JabRef references

Author	Title	Year	Journal/Proceedings	Reftype	DOI/URL
Anastasopoulos, D., Bronstein, A., Haslwanter, T., Fetter, M. and Dichgans, J.	The role of somatosensory input for the perception of verticality. [BibTeX]	1999	Ann N Y Acad Sci Vol. 871, pp. 379-383School: Department of Neurology, University of Ioannina, Greece. danastas@cc.uoi.gr	article
BibTeX: @article{Anastasopoulos1999, author = {D. Anastasopoulos and A. Bronstein and T. Haslwanter and M. Fetter and J. Dichgans}, title = {The role of somatosensory input for the perception of verticality.}, journal = {Ann N Y Acad Sci}, school = {Department of Neurology, University of Ioannina, Greece. danastas@cc.uoi.gr}, year = {1999}, volume = {871}, pages = {379--383} }
Anastasopoulos, D., Haslwanter, T., Bronstein, A., Fetter, M. and Dichgans, J.	Dissociation between the perception of body verticality and the visual vertical in acute peripheral vestibular disorder in humans. [Abstract] [BibTeX]	1997	Neurosci Lett Vol. 233(2-3), pp. 151-153School: Department of Neurology, Eberhard-Karls-Universität Tübingen, Germany.	article
Abstract: Estimates of the subjective visual and postural vertical were obtained from five patients with acute peripheral vestibular lesions and 20 normal subjects. The visual vertical was assessed by asking the subjects to align a target line to earth vertical by means of remote control. Postural vertical judgments were obtained by exposing them to rotational displacements in the roll plane while sitting on a motor-driven chair and requiring them to align their body to vertical using a joystick control. While the patients showed strong deviations of the visual vertical towards the lesion side, their postural vertical judgments remained veridical. We conclude that the above perceptions are not processed identically and that the participating sensory systems are differently weighted during these tasks.
BibTeX: @article{Anastasopoulos1997, author = {D. Anastasopoulos and T. Haslwanter and A. Bronstein and M. Fetter and J. Dichgans}, title = {Dissociation between the perception of body verticality and the visual vertical in acute peripheral vestibular disorder in humans.}, journal = {Neurosci Lett}, school = {Department of Neurology, Eberhard-Karls-Universität Tübingen, Germany.}, year = {1997}, volume = {233}, number = {2-3}, pages = {151--153} }
Anastasopoulos, D., Haslwanter, T., Fetter, M. and Dichgans, J.	Smooth pursuit eye movements and otolith-ocular responses are differently impaired in cerebellar ataxia. [Abstract] [BibTeX]	1998	Brain Vol. 121 ( Pt 8), pp. 1497-1505School: Department of Neurology, Eberhard-Karls-University, Tübingen, Germany.	article
Abstract: Horizontal and vertical smooth pursuit was compared with otolith-ocular responses in 11 patients with cerebellar ataxia and 21 normal subjects using three-dimensional magnetic search coil eye movement recordings. Otolith-ocular responses were investigated during off-vertical axis rotation. This stimulus induces nystagmus consisting of the exponentially decaying canalicular response, and an eye-velocity modulation and offset which arise from the excitation of the otoliths by the gravity vector, which lasts as long as the rotation continues. Otolith-ocular reflexes are intimately interrelated with visual tracking when real targets are viewed during linear motion. The responses of both the translational vestibulo-ocular reflex and the pursuit system have been shown to be linearly dependent on the inverse of the viewing distance, so that a common central pathway for the two systems has been suggested, probably travelling through the cerebellum. Thus, the aim of the study was to evaluate to what extent these reflexes are disturbed in cerebellar disease. The results confirm the earlier notion that in normal subjects pursuit performance is better for horizontal than for vertical tracking, and that it is better for upward than for downward tracking. This pattern is also found in patients. In addition, smooth pursuit performance is clearly degraded in patients, but the modulation of eye-velocity during off-vertical axis rotation is enhanced. Since the amount of this enhancement does not correlate with the amount of pursuit impairment, degradation of smooth pursuit and pathological enhancement of otolith-ocular responses seem to be independent effects of cerebellar degeneration. Thus, the increase in the otolith-ocular response in patients cannot be attributed to adaptational mechanisms trying to overcome the smooth pursuit deficiency; it is more likely to represent pathological disinhibition of otolith derived responses. The absence of compensatory eye-velocity offset during off-vertical axis rotation may reflect the fact that in patients the otolith signals are not utilized in computations thought to be important for spatial orientation mechanisms arising from the interaction of vestibular, visual and somatosensory signals.
BibTeX: @article{Anastasopoulos1998, author = {D. Anastasopoulos and T. Haslwanter and M. Fetter and J. Dichgans}, title = {Smooth pursuit eye movements and otolith-ocular responses are differently impaired in cerebellar ataxia.}, journal = {Brain}, school = {Department of Neurology, Eberhard-Karls-University, Tübingen, Germany.}, year = {1998}, volume = {121 ( Pt 8)}, pages = {1497--1505} }
Aw, S.T., Halmagyi, G.M., Haslwanter, T., Curthoys, I.S., Yavor, R.A. and Todd, M.J.	Three-dimensional vector analysis of the human vestibuloocular reflex in response to high-acceleration head rotations. II. responses in subjects with unilateral vestibular loss and selective semicircular canal occlusion. [Abstract] [BibTeX]	1996	J Neurophysiol Vol. 76(6), pp. 4021-4030School: Neurology Department, Royal Prince Alfred Hospital, Sydney, Camperdown, NSW, Australia.	article
Abstract: 1. We studied the three-dimensional input-output human vestibuloocular reflex (VOR) kinematics after selective loss of semicircular canal (SCC) function either through total unilateral vestibular deafferentation (uVD) or through single posterior SCC occlusion (uPCO), and showed large deficits in magnitude and direction in response to high-acceleration head rotations (head "impulses"). 2. A head impulse is a passive, unpredictable, high-acceleration (3,000-4,000 degrees/s2) head rotation through an amplitude of 10-20 degrees in roll, pitch, or yaw. The subjects were tested while seated in the upright position and focusing on a fixation target. Head and eye rotations were measured with the use of dual search coils, and were expressed as rotation vectors. A three-dimensional vector analysis was performed on the input-output VOR kinematics after uVD, to produce two indexes in the time domain: magnitude and direction. Magnitude is expressed as speed gain (G) and direction as misalignment angle (delta). 3. G. after uVD, was significantly lower than normal in both directions of head rotation during roll, pitch, and yaw impulses, and were much lower during ipsilesional than during contralesional roll and yaw impulses. At 80 ms from the onset of an impulse (i.e., near peak head velocity), G was 0.23 +/- 0.08 (SE) (ipsilesional) and 0.56 +/- 0.08 (contralesional) for roll impulses, 0.61 +/- 0.09 (up) and 0.72 +/- 0.10 (down) for pitch impulses, and 0.36 +/- 0.06 (ipsilesional) and 0.76 +/- 0.09 (contralesional) for yaw impulses (mean +/- 95% confidence intervals). 4. delta, after uVD, was significantly different from normal during ipsilesional roll and yaw impulses and during pitch-up and pitch-down impulses. delta was normal during contralesional roll and yaw impulses. At 80 ms from the onset of the impulse, delta was 30.6 +/- 4.5 (ipsilesional) and 13.4 +/- 5.0 (contralesional) for roll impulses, 23.7 +/- 3.7 (up) and 31.6 +/- 4.4 (down) for pitch impulses, and 68.7 +/- 13.2 (ipsilesional) and 11.0 +/- 3.3 (contralesional) for yaw impulses (mean +/- 95% confidence intervals). 5. VOR gain (gamma), after uVD, were significantly lower than normal for both directions of roll, pitch, and yaw impulses and much lower during ipsilesional than during contralesional roll and yaw impulses. At 80 ms from the onset of the head impulse, the gamma was 0.22 +/- 0.08 (ipsilesional) and 0.54 +/- 0.09 (contralesional) for roll impulses, 0.55 +/- 0.09 (up) and 0.61 +/- 0.09 (down) for pitch impulses, and 0.14 +/- 0.10 (ipsilesional) and 0.74 +/- 0.06 (contralesional) for yaw impulses (mean +/- 95% confidence intervals). Because gamma is equal to [G*cos (delta)], it is significantly different from its corresponding G during ipsilesional roll and yaw, and during all pitch impulses, but not during contralesional roll and yaw impulses. 6. After uPCO, pitch-vertical gamma during pitch-up impulses was reduced to the same extent as after uVD; roll-torsional gamma during ipsilesional roll impulses was significantly lower than normal but significantly higher than after uVD. At 80 ms from the onset of the head impulse, gamma was 0.32 +/- 0.13 (ipsilesional) and 0.55 +/- 0.16 (contralesional) for roll impulses, 0.51 +/- 0.12 (up) and 0.91 +/- 0.14 (down) for pitch impulses, and 0.76 +/- 0.06 (ipsilesional) and 0.73 +/- 0.09 (contralesional) for yaw impulses (mean +/- 95% confidence intervals). 7. The eye rotation axis, after uVD, deviates in the yaw plane, away from the normal interaural axis, toward the nasooccipital axis, during all pitch impulses. After uPCO, the eye rotation axis deviates in same direction as after uVD during pitch-up impulses, but is well aligned with the head rotation axis during pitch-down impulses.
BibTeX: @article{Aw1996, author = {S. T. Aw and G. M. Halmagyi and T. Haslwanter and I. S. Curthoys and R. A. Yavor and M. J. Todd}, title = {Three-dimensional vector analysis of the human vestibuloocular reflex in response to high-acceleration head rotations. II. responses in subjects with unilateral vestibular loss and selective semicircular canal occlusion.}, journal = {J Neurophysiol}, school = {Neurology Department, Royal Prince Alfred Hospital, Sydney, Camperdown, NSW, Australia.}, year = {1996}, volume = {76}, number = {6}, pages = {4021--4030} }
Aw, S.T., Haslwanter, T., Fetter, M. and Dichgans, J.	Three-dimensional spatial characteristics of caloric nystagmus. [Abstract] [BibTeX]	2000	Exp Brain Res Vol. 134(3), pp. 289-294School: Department of Neurology, Royal Prince Alfred Hospital, Camperdown, Sydney, NSW, Australia. sweea@icn.usyd.edu.au	article
Abstract: We investigated the three-dimensional spatial characteristics of caloric nystagmus during excitation and inhibition of the lateral semicircular canal in five normal human subjects. Each subject was repositioned in 45 degrees steps at 1-min intervals such that the right lateral semicircular canal plane was reoriented in pitch, from 135 degrees backwards from the upright position to 135 degrees forwards, while the right ear was continuously stimulated with air at 44 degrees C. In orientations in which caloric stimulus resulted in excitation of the right lateral semicircular canal, the eye velocity axis was orthogonal to the average orientation of the right lateral semicircular canal plane. However, in orientations in which caloric stimulus resulted in inhibition of the right lateral semicircular canal, the eye velocity axis was orthogonal to the average orientation of the left and not the right lateral semicircular canal plane. These findings suggest that velocity and direction of caloric nystagmus depend not only on the absolute magnitude of vestibular activity on the stimulated side but also on the differences in activity between the left and right vestibular nuclei, most probably mediated centrally via brainstem commissural pathways.
BibTeX: @article{Aw2000, author = {S. T. Aw and T. Haslwanter and M. Fetter and J. Dichgans}, title = {Three-dimensional spatial characteristics of caloric nystagmus.}, journal = {Exp Brain Res}, school = {Department of Neurology, Royal Prince Alfred Hospital, Camperdown, Sydney, NSW, Australia. sweea@icn.usyd.edu.au}, year = {2000}, volume = {134}, number = {3}, pages = {289--294} }
Aw, S.T., Haslwanter, T., Fetter, M., Heimberger, J. and Todd, M.J.	Contribution of the vertical semicircular canals to the caloric nystagmus. [Abstract] [BibTeX]	1998	Acta Otolaryngol Vol. 118(5), pp. 618-627School: Neurology Department, Royal Prince Alfred Hospital, NSW, Sydney, Australia. sweeo@icn.usyd.edu.au	article
Abstract: Modulation of the caloric nystagmus in response to repositioning the plane of one vertical semicircular canal from gravitational horizontal to vertical during continuous caloric stimulation was used to measure the vertical canal's contribution to the nystagmus. The rationale was to examine the thermovective response from one vertical canal at a time, after a temperature gradient had been established across its two limbs. The nystagmus was measured and analysed in three dimensions using orthogonal head-referenced coordinates. The magnitude of each semicircular canal's contribution to the overall caloric response, the canal vector, was determined in non-orthogonal, contravariant semicircular canal plane coordinates. By using the canal plane reorientation technique and contravariant canal plane coordinates, we were able to measure the proportional thermovective response magnitude generated by each vertical canal during caloric stimulation. We found that the anterior canal contributed about one-third and the posterior canal about one-tenth as much as the lateral canal did to the overall caloric response magnitude when it was reoriented from horizontal to vertical. Comparison of the eye rotation axis before and after each vertical canal plane reorientation, with the geometry of the stimulated semicircular canals, also showed directional modulation of the caloric nystagmus by the vertical canal response. When one vertical canal plane was horizontal during caloric stimulation, the eye rotation axis aligned with the resultant of the other vertical canal and the lateral canal response axes. After vertical canal plane reorientation, the eye rotation axis realigned towards the resultant of the maximally stimulated vertical canal and the lateral canal, by 55.2+/-33.9 degrees (mean+/-SD) after anterior canal plane reorientation and by 32.3+/-21.2 degrees after posterior canal reorientation.
BibTeX: @article{Aw1998, author = {S. T. Aw and T. Haslwanter and M. Fetter and J. Heimberger and M. J. Todd}, title = {Contribution of the vertical semicircular canals to the caloric nystagmus.}, journal = {Acta Otolaryngol}, school = {Neurology Department, Royal Prince Alfred Hospital, NSW, Sydney, Australia. sweeo@icn.usyd.edu.au}, year = {1998}, volume = {118}, number = {5}, pages = {618--627} }
Aw, S.T., Haslwanter, T., Halmagyi, G.M., Curthoys, I.S., Yavor, R.A. and Todd, M.J.	Three-dimensional vector analysis of the human vestibuloocular reflex in response to high-acceleration head rotations. I. Responses in normal subjects. [Abstract] [BibTeX]	1996	J Neurophysiol Vol. 76(6), pp. 4009-4020School: Neurology Department, Royal Prince Alfred Hospital, Sydney, Camperdown, NSW, Australia.	article
Abstract: 1. The kinematics of the human angular vestibuloocular reflex (VOR) in three dimensions was investigated in 12 normal subjects during high-acceleration head rotations (head "impulses"). A head impulse is a passive, unpredictable, high-acceleration (3,000-4,000 degrees/s2) head rotation of approximately 10-20 degrees in roll, pitch, or yaw, delivered with the subject in the upright position and focusing on a fixation target. Head and eye rotations were measured with dual search coils and expressed as rotation vectors. The first of these two papers describes a vector analysis of the three-dimensional input-output kinematics of the VOR as two indexes in the time domain: magnitude and direction. 2. Magnitude is expressed as speed gain (G) and direction as misalignment angle (delta). G is defined as the ratio of eye velocity magnitude (eye speed) to head velocity magnitude (head speed). delta is defined as the instantaneous angle by which the eye rotation axis deviates from perfect alignment with the head rotation axis in three dimensions. When the eye rotation axis aligns perfectly with the head rotation axis and when eye velocity is in a direction opposite to head velocity, delta = 0. The orientation of misalignment between the head and the eye rotation axes is characterized by two spatial misalignment angles, which are the projections of delta onto two orthogonal coordinate planes that intersect at the head rotation axis. 3. Time series of G were calculated for head impulses in roll, pitch, and yaw. At 80 ms after the onset of an impulse (i.e., near peak head velocity), values of G were 0.72 +/- 0.07 (counterclockwise) and 0.75 +/- 0.07 (clockwise) for roll impulses, 0.97 +/- 0.05 (up) and 1.10 +/- 0.09 (down) for pitch impulses, and 0.95 +/- 0.06 (right) and 1.01 +/- 0.07 (left) for yaw impulses (mean +/- 95% confidence intervals). 4. The eye rotation axis was well aligned with head rotation axis during roll, pitch, and yaw impulses: delta remained almost constant at approximately 5-10 degrees, so that the spatial misalignment angles were < or = 5 degrees. delta was 9.6 +/- 3.1 (counterclockwise) and 9.0 +/- 2.6 (clockwise) for roll impulses, 5.7 +/- 1.6 (up) and 6.1 +/- 1.9 (down) for pitch impulses, and 6.2 +/- 2.2 (right) and 7.9 +/- 1.5 (left) for yaw impulses (mean +/- 95% confidence intervals). 5. VOR gain (gamma) is the product of G and cos(delta). Because delta is small in normal subjects, gamma is not significantly different from G. At 80 ms after the onset of an impulse, gamma was 0.70 +/- 0.08 (counterclockwise) and 0.74 +/- 0.07 (clockwise) for roll impulses, 0.97 +/- 0.05 (up) and 1.09 +/- 0.09 (down) for pitch impulses, and 0.94 +/- 0.06 (right) and 1.00 +/- 0.07 (left) for yaw impulses (mean +/- 95% confidence intervals). 6. VOR latencies, estimated with a latency shift method, were 10.3 +/- 1.9 (SD) ms for roll impulses, 7.6 +/- 2.8 (SD) ms for pitch impulses, and 7.5 +/- 2.9 (SD) ms for yaw impulses. 7. We conclude that the normal VOR produces eye rotations that are almost perfectly compensatory in direction as well as in speed, but only during yaw and pitch impulses. During roll impulses, eye rotations are well aligned in direction, but are approximately 30% slower in speed.
BibTeX: @article{Aw1996a, author = {S. T. Aw and T. Haslwanter and G. M. Halmagyi and I. S. Curthoys and R. A. Yavor and M. J. Todd}, title = {Three-dimensional vector analysis of the human vestibuloocular reflex in response to high-acceleration head rotations. I. Responses in normal subjects.}, journal = {J Neurophysiol}, school = {Neurology Department, Royal Prince Alfred Hospital, Sydney, Camperdown, NSW, Australia.}, year = {1996}, volume = {76}, number = {6}, pages = {4009--4020} }
Bockisch, C.J. and Haslwanter, T.	Vestibular contribution to the planning of reach trajectories. [Abstract] [BibTeX]	2007	Exp Brain Res Vol. 182(3), pp. 387-397School: Department of Neurology, University Hospital Zürich, Frauenklinikstrasse 26, Zurich, Switzerland. Chris.Bockisch@usz.ch	article	DOI URL
Abstract: Reaching for an object while simultaneously rotating induces Coriolis and centrifugal inertial forces on the arm that require compensatory actions to maintain accuracy. We investigated whether the nervous system uses vestibular signals of head rotation to predict inertial forces. Human subjects reached in darkness to a remembered target 33 cm distant. Subjects were stationary, but experienced a strong vestibular rotation signal. We achieved this by rotating subjects at 360 degrees /s in yaw for 2 min and then stopping, and subjects reached during the 'post-rotary' period when the deceleration is interpreted by the vestibular system as a rotation in the opposite direction. Arm trajectories were straight in control trials without a rotary stimulus. With vestibular stimulation, trajectory curvature increased an average of 3 cm in the direction of the vestibular stimulation (e.g., to the right for a rightward yaw stimulus). Vestibular-induced curvature returned rapidly to normal, with an average time constant of 6 s. Movements also became longer as the vestibular stimulus diminished, and returned towards normal length with an average time constant of 5.6 s. In a second experiment we compared reaching with preferred and non-preferred hands, and found that they were similarly affected by vestibular stimulation. The reach curvatures were in the expected direction if the nervous system anticipated and attempted to counteract the presence of Coriolis forces based on the vestibular signals. Similarly, the shorter reaches may have occurred because the nervous system was attempting to compensate for an expected centrifugal force. Since vestibular stimulation also alters the perceived location of targets, vestibular signals probably influence all stages of the sensorimotor pathway transforming the desired goal of a reach into specific motor-unit innervation.
BibTeX: @article{Bockisch2007, author = {Christopher J Bockisch and Thomas Haslwanter}, title = {Vestibular contribution to the planning of reach trajectories.}, journal = {Exp Brain Res}, school = {Department of Neurology, University Hospital Zürich, Frauenklinikstrasse 26, Zurich, Switzerland. Chris.Bockisch@usz.ch}, year = {2007}, volume = {182}, number = {3}, pages = {387--397}, url = {http://dx.doi.org/10.1007/s00221-007-0997-x}, doi = {https://doi.org/10.1007/s00221-007-0997-x} }
Bockisch, C.J. and Haslwanter, T.	Three-dimensional eye position during static roll and pitch in humans. [Abstract] [BibTeX]	2001	Vision Res Vol. 41(16), pp. 2127-2137School: Department of Neurology, University Hospital Zürich, Frauenklinikstr. 26, 8091, Zürich, Switzerland. chris.bockisch@nos.usz.ch	article
Abstract: We investigated how three-dimensional (3D) eye position is influenced by static head position relative to gravity, a reflex probably mediated by the otolith organs. In monkeys, the torsional component of eye position is modulated by gravity, but little data is available in humans. Subjects were held in different head/body tilts in roll and pitch for 35 s while we measured 3D eye position with scleral coils, and we used methods that reduced torsion artifacts produced by the eyelids pressing on the contact lens and exit wire. 3D eye positions were described by planar fits to the data (Listing's plane), and changes in these planes showed how torsion varied with head position. Similar to findings in monkeys, the eyes counterrolled during roll tilts independent of horizontal and vertical eye position, reaching a maximum torsion of 4.9 degrees. Counterroll was not proportional to the shear force on the macula of the utricles: gain (torsion/sine of the head roll angle) decreased by 50% from near upright to ear down. During pitch forward, torsion increased when subjects looked right, and decreased when they looked left. However, the maximum change of torsion was only -0.06 degrees per degree of horizontal eye position, which is less than reported in monkey. Also in contrast to monkey, we found little change in torsion when subjects were pitched backwards.
BibTeX: @article{Bockisch2001, author = {C. J. Bockisch and T. Haslwanter}, title = {Three-dimensional eye position during static roll and pitch in humans.}, journal = {Vision Res}, school = {Department of Neurology, University Hospital Zürich, Frauenklinikstr. 26, 8091, Zürich, Switzerland. chris.bockisch@nos.usz.ch}, year = {2001}, volume = {41}, number = {16}, pages = {2127--2137} }
Bockisch, C.J., Straumann, D. and Haslwanter, T.	Human 3-D aVOR with and without otolith stimulation. [Abstract] [BibTeX]	2005	Exp Brain Res Vol. 161(3), pp. 358-367School: Department of Neurology, University Hospital Zürich, Frauenklinikstr. 26, 8091 Zürich, Switzerland. Chris.Bockisch@usz.ch	article	DOI URL
Abstract: We describe in detail the frequency response of the human three-dimensional angular vestibulo-ocular response (3-D aVOR) over a frequency range of 0.05-1 Hz. Gain and phase of the human aVOR were determined for passive head rotations in the dark, with the rotation axis either aligned with or perpendicular to the direction of gravity (earth-vertical or earth-horizontal). In the latter case, the oscillations dynamically stimulated both the otolith organs and the semi-circular canals. We conducted experiments in pitch and yaw, and compared the results with previously-published roll data. Regardless of the axis of rotation and the orientation of the subject, the gain in aVOR increased with frequency to about 0.3 Hz, and was approximately constant from 0.3 to 1 Hz. The aVOR gain during pitch and yaw rotations was larger than during roll rotations. Otolith and canal cues combined differently depending upon the axis of rotation: for torsional and pitch rotations, aVOR gain was higher with otolith input; for yaw rotations the aVOR was not affected by otolith stimulation. There was a phase lead in all three dimensions for frequencies below 0.3 Hz when only the canals were stimulated. For roll and pitch rotations this phase lead vanished with dynamic otolith stimulation. In contrast, the horizontal phase showed no improvement with additional otolith input during yaw rotations. The lack of a significant otolith contribution to the yaw aVOR was observed when subjects were supine, prone or lying on their sides. Our results confirm studies with less-natural stimuli (off-vertical axis rotation) that the otoliths contribute a head-rotation signal to the aVOR. However, the magnitude of the contribution depends on the axis of rotation, with the gain in otolith-canal cross-coupling being smallest for yaw axis rotations. This could be because, in humans, typical yaw head movements will stimulate the otoliths to a much lesser extent then typical pitch and roll head movements.
BibTeX: @article{Bockisch2005, author = {Christopher J Bockisch and Dominik Straumann and Thomas Haslwanter}, title = {Human 3-D aVOR with and without otolith stimulation.}, journal = {Exp Brain Res}, school = {Department of Neurology, University Hospital Zürich, Frauenklinikstr. 26, 8091 Zürich, Switzerland. Chris.Bockisch@usz.ch}, year = {2005}, volume = {161}, number = {3}, pages = {358--367}, url = {http://dx.doi.org/10.1007/s00221-004-2080-1}, doi = {https://doi.org/10.1007/s00221-004-2080-1} }
Bockisch, C.J., Straumann, D. and Haslwanter, T.	Eye movements during multi-axis whole-body rotations. [Abstract] [BibTeX]	2003	J Neurophysiol Vol. 89(1), pp. 355-366School: Department of Neurology, University Hospital Zürich, Switzerland. Chris.Bockisch@nos.usz.ch	article	DOI URL
Abstract: The semi-circular canals and the otolith organs both contribute to gaze stabilization during head movement. We investigated how these sensory signals interact when they provide conflicting information about head orientation in space. Human subjects were reoriented 90 degrees in pitch or roll during long-duration, constant-velocity rotation about the earth-vertical axis while we measured three-dimensional eye movements. After the reorientation, the otoliths correctly indicated the static orientation of the subject with respect to gravity, while the semicircular canals provided a strong signal of rotation. This rotation signal from the canals could only be consistent with a static orientation with respect to gravity if the rotation-axis indicated by the canals was exactly parallel to gravity. This was not true, so a cue-conflict existed. These conflicting stimuli elicited motion sickness and a complex tumbling sensation. Strong horizontal, vertical, and/or torsional eye movements were also induced, allowing us to study the influence of the conflict between the otoliths and the canals on all three eye-movement components. We found a shortening of the horizontal and vertical time constants of the decay of nystagmus and a trend for an increase in peak velocity following reorientation. The dumping of the velocity storage occurred regardless of whether eye velocity along that axis was compensatory to the head rotation or not. We found a trend for the axis of eye velocity to reorient to make the head-velocity signal from the canals consistent with the head-orientation signal from the otoliths, but this reorientation was small and only observed when subjects were tilted to upright. Previous models of canal-otolith interaction could not fully account for our data, particularly the decreased time constant of the decay of nystagmus. We present a model with a mechanism that reduces the velocity-storage component in the presence of a strong cue-conflict. Our study, supported by other experiments, also indicates that static otolith signals exhibit considerably smaller effects on eye movements in humans than in monkeys.
BibTeX: @article{Bockisch2003, author = {Christopher J Bockisch and Dominik Straumann and Thomas Haslwanter}, title = {Eye movements during multi-axis whole-body rotations.}, journal = {J Neurophysiol}, school = {Department of Neurology, University Hospital Zürich, Switzerland. Chris.Bockisch@nos.usz.ch}, year = {2003}, volume = {89}, number = {1}, pages = {355--366}, url = {http://dx.doi.org/10.1152/jn.00058.2002}, doi = {https://doi.org/10.1152/jn.00058.2002} }
Bockisch, C.J., Straumann, D., Hess, K. and Haslwanter, T.	Enhanced smooth pursuit eye movements in patients with bilateral vestibular deficits. [Abstract] [BibTeX]	2004	Neuroreport Vol. 15(17), pp. 2617-2620School: Department of Neurology, University Hospital Zürich, Frauenklinikstrasse 26, CH-8091 Zürich, Switzerland. Chris.Bockisch@usz.ch	article
Abstract: Patients with bilateral vestibular deficits experience unsteady gait and oscillopsia that can reduce the quality of life, though many patients adapt remarkably well and lead mostly normal lives. One source of adaptation could be the ability of sensory-motor systems to compensate for the vestibular loss by adaptive enhancement of their performance. We studied smooth-pursuit eye movements in five patients and six healthy control subjects using a step-ramp paradigm. Eye movements were measured with scleral search coils. Patients showed open- and closed-loop pursuit gains that were about 9% higher than controls. We suggest that the challenge of living with a deficient vestibular system caused an enhancement in the pursuit system, which contributes to the patient's overall compensation.
BibTeX: @article{Bockisch2004, author = {Christopher J Bockisch and Dominik Straumann and Klaus Hess and Thomas Haslwanter}, title = {Enhanced smooth pursuit eye movements in patients with bilateral vestibular deficits.}, journal = {Neuroreport}, school = {Department of Neurology, University Hospital Zürich, Frauenklinikstrasse 26, CH-8091 Zürich, Switzerland. Chris.Bockisch@usz.ch}, year = {2004}, volume = {15}, number = {17}, pages = {2617--2620} }
Brodsky, M.C., Haslwanter, T., Kori, A.A. and Straumann, D.	The role of volitional effort in the Bielschowsky head tilt test: a clinical and oculographic assessment. [Abstract] [BibTeX]	2000	Binocul Vis Strabismus Q Vol. 15(4), pp. 325-330School: Department of Ophthalmology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA. brodskymichaelc@exchange.uams.edu	article
Abstract: To determine whether volitional effort on the part of the subject can influence the results of the Bielschowsky Head Tilt Test.Bielschowsky Head Tilt testing was performed in five normal subjects. Vertical amplitudes were measured with prism alternate cover testing when the head tilt was voluntary (volitionally maintained in a tilted position by the subject), forced (restrained in the tilted position by the examiner while the patient actively resisted) and active (restrained in a tilted position by the examiner with the subject actively trying to increase the tilt). Three-dimensional scleral search coil recordings were performed in three additional normal subjects using the same paradigm to determine the effect of volition on the torsional positions of the eyes.No vertical deviation of the eyes was detectable with prism alternate cover testing in any position of tilt, regardless of whether the tilt was voluntary, forced, or active. Volitional attempts to tilt the head were preceded by a transient ipsiversive torsional movement of the measured eye, which was quickly followed by a normal ocular counterroll. Following completion of the counterroll, the position of the eyes was constant for any position of head tilt, regardless of whether the tilt was forced, active, or voluntary.Anticipatory torsional movements of the eyes are evoked by an attempted volitional head movement in the roll plane and its associated innervation to the cervical musculature. However, these volitional movements do not alter the final torsional position of the eyes, which is a function of the degree of head tilt and the normal ocular counterroll. These anticipatory torsional movements do not influence the results of the Bielschowsky Head Tilt Test clinically by prism alternate cover testing.
BibTeX: @article{Brodsky2000, author = {M. C. Brodsky and T. Haslwanter and A. A. Kori and D. Straumann}, title = {The role of volitional effort in the Bielschowsky head tilt test: a clinical and oculographic assessment.}, journal = {Binocul Vis Strabismus Q}, school = {Department of Ophthalmology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA. brodskymichaelc@exchange.uams.edu}, year = {2000}, volume = {15}, number = {4}, pages = {325--330} }
Carey, J.P., Hirvonen, T., Peng, G.C.Y., Santina, C.C.D., Cremer, P.D., Haslwanter, T. and Minor, L.B.	Changes in the angular vestibulo-ocular reflex after a single dose of intratympanic gentamicin for Ménière's disease. [BibTeX]	2002	Ann N Y Acad Sci Vol. 956, pp. 581-584School: Department of Otolaryngology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA. jcarey@jhmi.edu	article
BibTeX: @article{Carey2002a, author = {J. P. Carey and T. Hirvonen and G. C Y Peng and C. C. Della Santina and P. D. Cremer and T. Haslwanter and L. B. Minor}, title = {Changes in the angular vestibulo-ocular reflex after a single dose of intratympanic gentamicin for Ménière's disease.}, journal = {Ann N Y Acad Sci}, school = {Department of Otolaryngology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA. jcarey@jhmi.edu}, year = {2002}, volume = {956}, pages = {581--584} }
Carey, J.P., Minor, L.B., Peng, G.C.Y., Santina, C.C.D., Cremer, P.D. and Haslwanter, T.	Changes in the three-dimensional angular vestibulo-ocular reflex following intratympanic gentamicin for Ménière's disease. [Abstract] [BibTeX]	2002	J Assoc Res Otolaryngol Vol. 3(4), pp. 430-443School: Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University, Baltimore, MD 21287, USA. jcarey@jhmi.edu	article	DOI URL
Abstract: The 3-dimensional angular vestibulo-ocular reflexes (AVOR) elicited by rapid rotary head thrusts were studied in 17 subjects with unilateral Ménière's disease before and 2-10 weeks after treatment with intratympanic gentamicin and in 13 subjects after surgical unilateral vestibular destruction (SUVD). Each head thrust was in the horizontal plane or in either diagonal plane of the vertical semicircular canals, so that each head thrust effectively stimulated only one pair of canals. The AVOR gains (eye velocity/head velocity during the 30 ms before peak head velocity) for the head thrusts exciting each individual canal were averaged and taken as a measure of the function of that canal. Prior to intratympanic gentamicin, gains for head thrusts that excited canals on the affected side were 0.91 +/- 0.20 (horizontal canal, HC), 0.78 +/- 0.20 (anterior canal, AC), and 0.83 +/- 0.10 (posterior canal, PC). The asymmetries between these gain values and those for head thrusts that excited the contralateral canals were <2%. In contrast, caloric asymmetries averaged 40% +/- 32%. Intratympanic gentamicin resulted in decreased gains attributable to each canal on the treated side: 0.40 +/- 0.12 (HC), 0.35 +/- 0.14 (AC), 0.31 +/- 0.14 (PC) (p <0.01). However, the gains attributable to contralateral canals dropped only slightly, resulting in marked asymmetries between gains for excitation of ipsilateral canals versus their contralateral mates: HC: 34% +/- 12%, AC: 24% +/- 25%, and PC: 42% +/- 13%. There was no difference in the AVOR gain for excitation of the ipsilateral HC after gentamicin in patients who received a single intratympanic injection (0.39 +/- 0.11, n = 12) in comparison to those who received 2-3 injections (0.42 +/- 0.15, n = 5, p = 0.7). Gain decreases attributed to the gentamicin-treated HC and AC were not as severe as those observed after SUVD. This finding suggests that intratympanic gentamicin causes a partial vestibular lesion that may involve preservation of spontaneous discharge and/or rotational sensitivity of afferents.
BibTeX: @article{Carey2002, author = {John P Carey and Lloyd B Minor and Grace C Y Peng and Charles C Della Santina and Phillip D Cremer and Thomas Haslwanter}, title = {Changes in the three-dimensional angular vestibulo-ocular reflex following intratympanic gentamicin for Ménière's disease.}, journal = {J Assoc Res Otolaryngol}, school = {Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University, Baltimore, MD 21287, USA. jcarey@jhmi.edu}, year = {2002}, volume = {3}, number = {4}, pages = {430--443}, url = {http://dx.doi.org/10.1007/s101620010053}, doi = {https://doi.org/10.1007/s101620010053} }
Clarke, A.H. and Haslwanter, T.	The orientation of Listing's Plane in microgravity. [Abstract] [BibTeX]	2007	Vision Res Vol. 47(25), pp. 3132-3140School: Charité Medical School, Campus Benjamin Franklin, Hindenburgdamm 30, Berlin, Federal Republic of Germany. andrew.clarke@charite.de	article	DOI URL
Abstract: The orientation of Listing's Plane (LP) was examined under one-g and zero-g conditions during parabolic flight. Ten healthy subjects participated in the experiment. In zero-g the orientation of LP was consistently altered. LP elevation was tilted backwards by approx. 10 degrees (p=0.003). The azimuth angles of the left and right eyes also diverged in zero-g, with a statistically significant change (p=0.04) in the vergence angle between 6.1 degrees and 11.8 degrees . A discernible dissociation in torsional eye position was also observed, which proved to be statistically significant (p=0.03). The thickness of LP was found to be of the order of 1 degrees , and was not significantly altered by the transitions between one-g and zero-g. Additional control experiments involving repeated measurements of LP under normal laboratory conditions demonstrated that the parameters of LP remain stable in the individual. The parabolic flight results demonstrate that in contrast to re-orientation in the one-g gravitational field, the elimination of gravity represents a qualitative change for the vestibular and oculomotor systems. It appears that given the lack of voluntary control of ocular torsion, the tonic otolith afferences are instrumental in the stabilisation of torsional eye position and consequently of Listing's Plane. The observed torsional divergence also provides support for the so-called otolith asymmetry hypothesis.
BibTeX: @article{Clarke2007, author = {Andrew H Clarke and Thomas Haslwanter}, title = {The orientation of Listing's Plane in microgravity.}, journal = {Vision Res}, school = {Charité Medical School, Campus Benjamin Franklin, Hindenburgdamm 30, Berlin, Federal Republic of Germany. andrew.clarke@charite.de}, year = {2007}, volume = {47}, number = {25}, pages = {3132--3140}, url = {http://dx.doi.org/10.1016/j.visres.2007.09.001}, doi = {https://doi.org/10.1016/j.visres.2007.09.001} }
Curthoys, I.S., Haslwanter, T., Black, R.A., Burgess, A.M., Halmagyi, G.M., Topple, A.N. and Todd, M.J.	Off-center yaw rotation: effect of naso-occipital linear acceleration on the nystagmus response of normal human subjects and patients after unilateral vestibular loss. [Abstract] [BibTeX]	1998	Exp Brain Res Vol. 123(4), pp. 425-438School: Department of Psychology, University of Sydney, NSW, Australia. ianc@psych.usyd.edu.au	article
Abstract: Dual search coils were used to record horizontal, vertical and torsional eye movement components of one eye during nystagmus caused by off-center yaw rotation (yaw centrifugation). Both normal healthy human subjects (n=7) and patients with only one functioning labyrinth (n=12) were studied in order to clarify how the concomitant linear acceleration affected the nystagmus response. Each subject was seated with head erect on the arm of a fixed-chair human centrifuge, 1 m away from the center of the rotation, and positioned to be facing along a radius; either towards (facing-in) or away from (facing-out) the center of rotation. Both yaw right and yaw left angular accelerations of 10 degrees s(-2) from 0 to 200 degrees/s were studied. During rotation a centripetal linear acceleration (increasing from 0 to 1.24xg units) was directed along the subject's naso-occipital axis resulting in a shift of the resultant angle of the gravitoinertial acceleration (GIA) of 51 degrees in the subject's pitch plane and an increase in the total GIA magnitude from 1.0 to 1.59xg. In normal subjects during the angular acceleration off-center there were, in addition to the horizontal eye velocity components, torsional and vertical eye velocities present. The magnitude of these additional components, although small, was larger than observed during similar experiments with on-center angular acceleration (Haslwanter et al. 1996), and the change in these components is attributed to the additional effect of the linear acceleration stimulation. In the pitch plane the average size of the shift of the axis of eye velocity (AEV) during the acceleration was about 8 degrees for a 51 degrees shift of the GIA (around 16% of the GIA shift) so that the AEV-GIA alignment was inadequate. There was a very marked difference in the size of the AEV shift depending on whether the person was facing-in [AEV shift forward (i.e. non-compensatory) of about 4 degrees] or facing-out [AEV shift forward (i.e. compensatory) of around 12 degrees]. The linear acceleration decreased the time constant of decay of the horizontal component of the post-rotatory nystagmus: from an average of 24.8 degrees/s facing-in to an average of 11.3 degrees/s facing-out. The linear acceleration dumps torsional eye velocity in an manner analogous to, but independent of, the dumping of horizontal eye velocity. Patients with UVD had dramatically reduced torsional eye velocities for both facing-in and facing-out headings, and there was little if any shift of the AEV in UVD patients. The relatively small effects of linear acceleration on human canal-induced nystagmus found here confirms other recent studies in humans (Fetter et al. 1996) in contrast to evidence from monkeys and emphasizes the large and important differences between humans and monkeys in otolith-canal interaction. Our results confirm the vestibular control of the axis of eye velocity of humans is essentially head-referenced whereas in monkeys that control is essentially space-referenced.
BibTeX: @article{Curthoys1998, author = {I. S. Curthoys and T. Haslwanter and R. A. Black and A. M. Burgess and G. M. Halmagyi and A. N. Topple and M. J. Todd}, title = {Off-center yaw rotation: effect of naso-occipital linear acceleration on the nystagmus response of normal human subjects and patients after unilateral vestibular loss.}, journal = {Exp Brain Res}, school = {Department of Psychology, University of Sydney, NSW, Australia. ianc@psych.usyd.edu.au}, year = {1998}, volume = {123}, number = {4}, pages = {425--438} }
Fetter, M., Aw, S., Haslwanter, T., Heimberger, J. and Dichgans, J.	Three-dimensional eye movement analysis during caloric stimulation used to test vertical semicircular canal function. [Abstract] [BibTeX]	1998	Am J Otol Vol. 19(2), pp. 180-187School: Department of Neurology, Eberhard-Karls-University, Tübingen, Germany.	article
Abstract: Quantitative caloric testing is considered to be one of the most sensitive parameters in the diagnosis of peripheral vestibular disorders. In the past, because of limitations in the methods, the evaluation of the caloric response was restricted to mainly lateral semicircular canal functions. In this study, the authors tried to extend caloric testing to the function of all semicircular canals by using three-dimensional (3-D) analysis techniques.The authors studied in seven normal subjects 3-D eye movement responses to air caloric of the right ear with the subjects positioned in standard caloric position (lateral semicircular canal vertical) or such that one of the three semicircular canals of the right side was horizontal. Movement of the left eye was measured in 3-D with a dual-magnetic search coil. During stimulation, 10 seconds of maximum response were selected and desaccaded to yield the slow-phase velocity profile. From this profile, the average magnitude and direction of the eye rotation axis (velocity vector) were calculated in head coordinates.In all subjects, in standard caloric position, warm caloric produced eye velocity vectors that clustered closely along the direction expected from an excitation of the right lateral semicircular canal. When the subjects were positioned with one of the vertical semicircular canals horizontal, the orientation of the velocity vectors shifted toward a direction expected from the combined excitation of the lateral and the other vertical semicircular canal and vice versa.The 3-D eye movement recordings during caloric stimulation in different head positions allow the evaluation of the function of all semicircular canals.
BibTeX: @article{Fetter1998, author = {M. Fetter and S. Aw and T. Haslwanter and J. Heimberger and J. Dichgans}, title = {Three-dimensional eye movement analysis during caloric stimulation used to test vertical semicircular canal function.}, journal = {Am J Otol}, school = {Department of Neurology, Eberhard-Karls-University, Tübingen, Germany.}, year = {1998}, volume = {19}, number = {2}, pages = {180--187} }
Fetter, M. and Haslwanter, T.	3D eye movements--basics and clinical applications. [Abstract] [BibTeX]	1999	J Vestib Res Vol. 9(3), pp. 181-187School: Department of Neurology, Eberhard-Karls University, Tübingen, Germany. michael.fetter@uni-tuebingen.de	article
Abstract: The eye muscles in humans are arranged such that they allow rotations of the globe about any axis in three-dimensional space. Only 3D analysis techniques will suffice to describe the sometimes complex dependencies between the elicited eye movements and the stimulation conditions. With the recent availability of modern 3D eye movement measurement techniques and the further development of appropriate mathematical descriptions, we are now able to study eye movements in all three degrees of freedom. This article describes the basic mathematical tools for 3D eye movement analysis like rotation vectors, reference frames, coordinate systems, and the concept of Listing's law. In a second part some clinical applications are presented. The close coupling between the vestibular and the oculomotor system suggests that by observing spontaneous and elicited eye movements in the case of an acute unilateral vestibular pathology we might be able to find out which parts of the vestibular system (that is, which of the semicircular canals or which of the otoliths) are affected. The rationale of such an analysis is based on the observation that electrical stimulation of single semicircular canal afferents in animals induces eye movements that lie roughly in the plane of the canal. It is, therefore, possible to deduce which canals cause the eye movements observed when only some parts of the vestibular system are defective. Thus, the analysis of 3D movements not only provides an improved understanding of how the brain organizes movement in 3D space, but also has the potential to significantly improve our diagnostic capabilities.
BibTeX: @article{Fetter1999, author = {M. Fetter and T. Haslwanter}, title = {3D eye movements--basics and clinical applications.}, journal = {J Vestib Res}, school = {Department of Neurology, Eberhard-Karls University, Tübingen, Germany. michael.fetter@uni-tuebingen.de}, year = {1999}, volume = {9}, number = {3}, pages = {181--187} }
Fetter, M., Haslwanter, T., Bork, M. and Dichgans, J.	New insights into positional alcohol nystagmus using three-dimensional eye-movement analysis. [Abstract] [BibTeX]	1999	Ann Neurol Vol. 45(2), pp. 216-223School: Department of Neurology, Eberhard-Karls-University, Tübingen, Germany.	article
Abstract: The semicircular canals selectively transduce angular velocity and are normally insensitive to gravity and linear acceleration. In acute alcohol intoxication, however, the cupula becomes lighter than the endolymph, rendering it sensitive to gravity (buoyancy hypothesis). This results in positional alcohol nystagmus (PAN) and rotatory vertigo. We evaluated PAN in 8 normal subjects by means of three-dimensional eye-movement analysis in an attempt to clarify if the buoyancy mechanism is sufficient to explain PAN. Forty minutes after intake of 0.8 g of alcohol/kg of body weight, the subjects were positioned such that the lateral canals were earth vertical. They were then rotated in the plane of the lateral canals about an earth-horizontal axis to either 45 degrees or 90 degrees , right or left ear down, and eye movements were recorded for 40 seconds in each position. The spatial analysis of the responses showed that in addition to the nystagmus induced by the buoyancy of all six cupulae, alcohol intoxication also causes a vertical velocity offset (in all subjects, slow phase down) that is independent of the orientation of the subject in space. The offset may represent a toxic effect on central vestibular pathways, producing a tone imbalance of the vertical vestibulo-ocular reflex.
BibTeX: @article{Fetter1999a, author = {M. Fetter and T. Haslwanter and M. Bork and J. Dichgans}, title = {New insights into positional alcohol nystagmus using three-dimensional eye-movement analysis.}, journal = {Ann Neurol}, school = {Department of Neurology, Eberhard-Karls-University, Tübingen, Germany.}, year = {1999}, volume = {45}, number = {2}, pages = {216--223} }
Haslwanter, T.	Mechanics of eye movements: implications of the "orbital revolution". [Abstract] [BibTeX]	2002	Ann N Y Acad Sci Vol. 956, pp. 33-41School: Department of Neurology, University Hospital Zurich and Institute of Theoretical Physics, ETH Zurich, Switzerland. haslwant@neurol.unizh.ch	article
Abstract: Our understanding of the functional structure of extraocular muscles has undergone a profound change: while these muscles used to be represented by strings running straight from their origin in the posterior orbita to their insertion on the globe, we now know that their paths and pulling directions are dominated by fibromuscular pulley structures, keeping them close to the orbital wall for most of their path. An overview is presented of recent models that have been developed to understand the implications of muscle pulleys for the neural control of eye movements and the applications of such models to the interpretation of experimental data.
BibTeX: @article{Haslwanter2002, author = {Thomas Haslwanter}, title = {Mechanics of eye movements: implications of the "orbital revolution".}, journal = {Ann N Y Acad Sci}, school = {Department of Neurology, University Hospital Zurich and Institute of Theoretical Physics, ETH Zurich, Switzerland. haslwant@neurol.unizh.ch}, year = {2002}, volume = {956}, pages = {33--41} }
Haslwanter, T.	Mathematics of three-dimensional eye rotations. [Abstract] [BibTeX]	1995	Vision Res Vol. 35(12), pp. 1727-1739School: Department of Psychology, University of Sydney, NSW, Australia.	article
Abstract: The recording of three-dimensional eye position has become the accepted standard in oculomotor research. In this paper we review the mathematics underlying the representation of three-dimensional eye movements. Rotation matrices, rotation vectors and quaternions are presented, and their relations described. The connection between search coils and rotation matrices is explained, as well as the connection between eye position and eye velocity. While examples of applications of the formulas to vestibulo-ocular research are given, the methods and mathematical analyses are also useful for studying other motor systems.
BibTeX: @article{Haslwanter1995a, author = {T. Haslwanter}, title = {Mathematics of three-dimensional eye rotations.}, journal = {Vision Res}, school = {Department of Psychology, University of Sydney, NSW, Australia.}, year = {1995}, volume = {35}, number = {12}, pages = {1727--1739} }
Haslwanter, T., Buchberger, M., Kaltofen, T., Hoerantner, R. and Priglinger, S.	SEE++: a biomechanical model of the oculomotor plant. [Abstract] [BibTeX]	2005	Ann N Y Acad Sci Vol. 1039, pp. 9-14School: Upper Austrian Research, Department for MedicalInformatics, Softwarepark Hagenberg, Hauptstrasse 99, A-4232 Hagenberg, Austria. thomas.haslwanter@uar.at	article	DOI URL
Abstract: The consequences of changes in the oculomotor system on the three-dimensional eye movements are difficult to grasp. Although changes to the rectus muscles can still be approximately understood with simplified geometric models, this approach no longer works with the oblique muscles. It is shown how SEE++, a biomechanical model of the oculomotor plant that was built on the ideas of Miller and Robinson (1984) can improve the understanding of the effects of changes to the oblique eye muscles. By displaying only selected muscles, and by illustrating the relative contribution of these muscles through color-coding the bulb surface, the functional properties of the oblique muscles can be presented in a much clearer way. Investigating the effects of a hyperactive inferior oblique muscle shows that this type of model can help to clarify the functional cause of a pathology, which can otherwise be unclear, even for common pathologies.
BibTeX: @article{Haslwanter2005, author = {T. Haslwanter and M. Buchberger and T. Kaltofen and R. Hoerantner and S. Priglinger}, title = {SEE++: a biomechanical model of the oculomotor plant.}, journal = {Ann N Y Acad Sci}, school = {Upper Austrian Research, Department for MedicalInformatics, Softwarepark Hagenberg, Hauptstrasse 99, A-4232 Hagenberg, Austria. thomas.haslwanter@uar.at}, year = {2005}, volume = {1039}, pages = {9--14}, url = {http://dx.doi.org/10.1196/annals.1325.002}, doi = {https://doi.org/10.1196/annals.1325.002} }
Haslwanter, T., Curthoys, I.S., Black, R.A., Topple, A.N. and Halmagyi, G.M.	The three-dimensional human vestibulo-ocular reflex: response to long-duration yaw angular accelerations. [Abstract] [BibTeX]	1996	Exp Brain Res Vol. 109(2), pp. 303-311School: Department of Psychology, University of Sydney, NSW, Australia. ianc@psychvax.psych.su.oz.au	article
Abstract: We recorded three-dimensional eye movements during angular acceleration steps from 0 to 250 degrees/s at 20 degrees/s2 about an earth-vertical axis. Experiments were performed on 27 normal subjects and on 19 patients who had recovered well from unilateral vestibular deafferentation on the right or left side. In addition to compensatory horizontal eye movements, significant vertical and torsional eye movement components were elicited. These vertical and torsional eye velocity traces led to a shift of the axis of eye velocity away from the axis of head velocity. Horizontal, vertical, and torsional velocity components showed clear differences between normals and patients with unilateral vestibular deafferentation. In normals, the axis of eye velocity tilted backward and slightly away from the axis of head velocity. Patients showed similar, but more pronounced, shifts during rotations toward the intact ear and shifts in the opposite direction for rotations toward the operated ear. Eye velocity traces were analyzed with special consideration given to the orientation of the axis of eye velocity. We speculate that the vertical and torsional velocity components may be due to the effects of Listing's plane, as well as the contributions of the otolith signals.
BibTeX: @article{Haslwanter1996, author = {T. Haslwanter and I. S. Curthoys and R. A. Black and A. N. Topple and G. M. Halmagyi}, title = {The three-dimensional human vestibulo-ocular reflex: response to long-duration yaw angular accelerations.}, journal = {Exp Brain Res}, school = {Department of Psychology, University of Sydney, NSW, Australia. ianc@psychvax.psych.su.oz.au}, year = {1996}, volume = {109}, number = {2}, pages = {303--311} }
Haslwanter, T., Curthoys, I.S., Black, R. and Topple, A.	Orientation of Listing's plane in normals and in patients with unilateral vestibular deafferentation. [Abstract] [BibTeX]	1994	Exp Brain Res Vol. 101(3), pp. 525-528School: Department of Psychology, University of Sydney, NSW, Australia.	article
Abstract: The parameters characterizing Listing's plane have been determined in a group of normal subjects, and in patients who have had unilateral vestibular deafferentation on the right or left side. All patients were well compensated. There was no statistically significant difference in the orientation of Listing's plane between either of these groups: Listing's plane was approximately perpendicular to the horizontal stereotaxic plane and showed a systematic temporal tilt, i.e., it tilted right for the right eye, and left for the left eye. We also found a considerable intersubject variability in the orientation of Listing's plane. The effect of this variability on the interpretation of three-dimensional eye position and velocity data is discussed.
BibTeX: @article{Haslwanter1994, author = {T. Haslwanter and I. S. Curthoys and R. Black and A. Topple}, title = {Orientation of Listing's plane in normals and in patients with unilateral vestibular deafferentation.}, journal = {Exp Brain Res}, school = {Department of Psychology, University of Sydney, NSW, Australia.}, year = {1994}, volume = {101}, number = {3}, pages = {525--528} }
Haslwanter, T., Curthoys, I.S., Halmagyi, G.M., Black, R.A., Topple, A.N. and Todd, M.J.	Torsional eye velocity components during yaw angular acceleration identify the side of unilateral vestibular deafferentation. [Abstract] [BibTeX]	1995	Acta Otolaryngol Suppl Vol. 520 Pt 1, pp. 62-64School: Department of Psychology, University of Sydney, NSW, Australia.	article
Abstract: Using dual torsion scleral search coils we have recorded 3-dimensional eye position during yaw angular accelerations of 20 degrees/s2 about an earth vertical axis in healthy subjects and in patients with unilateral vestibular deafferentation (UVD). These experiments produced two interesting results: i) even in healthy subjects, the axis of eye velocity did not coincide with the (earth vertical) stimulus axis during centred rotation; ii) Patients with UVD had torsional eye velocity components that were systematically different from those in normal subjects. While in normals the direction of the torsional component of the eye velocity depended on the direction of rotation and was on average approximately symmetric for CW and CCW yaw rotation, there was a clear asymmetry in patients, which was distinctly different for left and right UVD.
BibTeX: @article{Haslwanter1995b, author = {T. Haslwanter and I. S. Curthoys and G. M. Halmagyi and R. A. Black and A. N. Topple and M. J. Todd}, title = {Torsional eye velocity components during yaw angular acceleration identify the side of unilateral vestibular deafferentation.}, journal = {Acta Otolaryngol Suppl}, school = {Department of Psychology, University of Sydney, NSW, Australia.}, year = {1995}, volume = {520 Pt 1}, pages = {62--64} }
Haslwanter, T., Hoerantner, R. and Priglinger, S.	Reduction of ocular muscle power by splitting of the rectus muscle I: biomechanics. [Abstract] [BibTeX]	2004	Br J Ophthalmol Vol. 88(11), pp. 1403-1408School: Department of Neurology, University Hospital Zürich, Switzerland. thomas.haslwanter@uar.at	article	DOI URL
Abstract: Based on mechanical considerations, the authors have developed a new approach to weakening oculomotor muscles. They present the biomechanical considerations that have encouraged them to explore this approach, and compare it with existing surgical techniques. Results of application to patients are given in the companion paper, and do not require an analytical understanding of the underlying mechanics.Using a simple biomechanical model for the oculomotor system and vector component analysis, the eye position dependent torque exerted by extraocular muscles on the eyeball was investigated. This model was applied to the healthy eye, as well as to different surgical procedures (Cuppers' Fadenoperation, Y-split muscle recessions, botulinum toxin, and simple muscle recessions).These investigations suggest that a Y-split muscle recession is a simple and efficient way to weaken ocular rectus muscles. Compared to alternative surgical procedures, undesired radial forces that can lead to post-surgical complications can be kept to a minimum. The authors further speculate that their good results may in part be because of possible preservation of proprioceptive inputs from the insertion of the extraocular muscle.
BibTeX: @article{Haslwanter2004, author = {T. Haslwanter and R. Hoerantner and S. Priglinger}, title = {Reduction of ocular muscle power by splitting of the rectus muscle I: biomechanics.}, journal = {Br J Ophthalmol}, school = {Department of Neurology, University Hospital Zürich, Switzerland. thomas.haslwanter@uar.at}, year = {2004}, volume = {88}, number = {11}, pages = {1403--1408}, url = {http://dx.doi.org/10.1136/bjo.2004.042713}, doi = {https://doi.org/10.1136/bjo.2004.042713} }
Haslwanter, T., Jaeger, R. and Fetter, M.	Otolith-canal interaction during pitch while rotating. [BibTeX]	1999	Ann N Y Acad Sci Vol. 871, pp. 410-413School: Department of Neurology, University Hospital Tübingen, Germany. haslwant@neurol.unizh.ch	article
BibTeX: @article{Haslwanter1999, author = {T. Haslwanter and R. Jaeger and M. Fetter}, title = {Otolith-canal interaction during pitch while rotating.}, journal = {Ann N Y Acad Sci}, school = {Department of Neurology, University Hospital Tübingen, Germany. haslwant@neurol.unizh.ch}, year = {1999}, volume = {871}, pages = {410--413} }
Haslwanter, T., Jaeger, R., Mayr, S. and Fetter, M.	Three-dimensional eye-movement responses to off-vertical axis rotations in humans. [Abstract] [BibTeX]	2000	Exp Brain Res Vol. 134(1), pp. 96-106School: Department of Neurology, Zurich, Switzerland.	article
Abstract: We recorded three-dimensional eye movements elicited by velocity steps about axes that were tilted with respect to the earth-vertical. Subjects were accelerated in 1 s from zero to 100 degrees/s, and the axis of rotation was tilted by 15 degrees, 30 degrees, 60 degrees, or 90 degrees. This stimulus induced a constant horizontal velocity component that was directed opposite to the direction of rotation, as well as a modulation of the horizontal, vertical and torsional components with the frequency of the rotation. The maximum steady-state response in the horizontal constant-velocity component was much smaller than in other species (about 6 degrees/s), reaching a maximum at a tilt angle of about 60 degrees. While the amplitude of the horizontal modulation component increased up to a tilt angle of 90 degrees (8.4 degrees/s), the vertical and torsional modulation amplitudes saturated around 60 degrees (ca. 2.5 degrees/s). At small tilt angles, the horizontal modulation component showed a small phase lag with respect to the chair position, which turned into a small phase lead at large tilt angles. The torsional component showed a phase lead that increased with increasing tilt angle. The vertical and torsional velocity modulation at large tilt angles was not predicted by a recent model of otolith-canal interaction by Merfeld. Agreement between model and experimental data could be achieved, however, by introducing a constant force along the body's z-axis to compensate for the gravitational pull on the otoliths in the head-upright position. This approach had been suggested previously to explain the direction of the perceived subjective vertical during roll under different g-levels, and produced in our model the observed vertical and torsional modulation components at large tilt angles.
BibTeX: @article{Haslwanter2000, author = {T. Haslwanter and R. Jaeger and S. Mayr and M. Fetter}, title = {Three-dimensional eye-movement responses to off-vertical axis rotations in humans.}, journal = {Exp Brain Res}, school = {Department of Neurology, Zurich, Switzerland.}, year = {2000}, volume = {134}, number = {1}, pages = {96--106} }
Haslwanter, T. and Minor, L.B.	Nystagmus induced by circular head shaking in normal human subjects. [Abstract] [BibTeX]	1999	Exp Brain Res Vol. 124(1), pp. 25-32School: Department of Neurology, University Hospital Tübingen, Germany. thomash@uni-tuebingen.de	article
Abstract: We recorded three-dimensional eye and head movements during circular, horizontal, vertical, and torsional head shaking in six human subjects with normal vestibular function. With circular head shaking, the stimulation of the canals by the termination of the head movement is similar to that following a step in velocity about the naso-occipital axis. A large torsional nystagmus with slow phase eye velocity of about 20 degrees/s was observed upon cessation of circular head shaking. The three-dimensional eye movements expected from stimulation of the semicircular canals by the head-shaking maneuvers were calculated. The predicted activation of the canals was determined by projecting the head velocity (in head coordinates) into the canal planes and then processing the signal with the transfer function of the canals. The torsional eye velocity components predicted by the stimulation of the canals matched the recorded ones. We observed small horizontal eye velocities that could not be predicted by the stimulation of the canals alone. No eye movements were observed after the end of head shaking about a fixed horizontal or vertical axis. The eye velocities following the termination of head oscillations in the roll plane were small. The analysis methods developed for this study may be useful in the investigation of eye movements elicited by other types of three-dimensional head movements.
BibTeX: @article{Haslwanter1999a, author = {T. Haslwanter and L. B. Minor}, title = {Nystagmus induced by circular head shaking in normal human subjects.}, journal = {Exp Brain Res}, school = {Department of Neurology, University Hospital Tübingen, Germany. thomash@uni-tuebingen.de}, year = {1999}, volume = {124}, number = {1}, pages = {25--32} }
Haslwanter, T. and Ong, J.	Applying knowledge--challenges in bringing scientific advances to dizzy patients. [Abstract] [BibTeX]	2009	Ann N Y Acad Sci Vol. 1164, pp. 309-315School: Upper Austria University of Applied Sciences, Linz, Austria. thomas.haslwanter@fh-linz.at	article	DOI URL
Abstract: Simple diagnostic or therapeutic procedures can produce tremendous benefits for dizzy patients. To see how new ideas in the laboratory evolve into benefits for patients, an attempt to analyze how the corresponding information is distributed was made. To quantify that flow of information, a number of new scientific publications, citation numbers, and a number of new books on relevant subjects were looked at. For vertigo, this approach was facilitated by the fact that the diagnostic procedures for benign paroxysmal positioning vertigo (BPPV) and for canal paresis can be traced back to seminal publications. Results indicate that the current way of disseminating new information used here is working well, and that new ideas on diagnosis and treatment are readily available to practitioners. However, the application of new methods is limited by the availability of the required technology. It is conjectured that the technological requirements have become more complex over time, leading to a slower uptake of new technology.
BibTeX: @article{Haslwanter2009, author = {Thomas Haslwanter and James Ong}, title = {Applying knowledge--challenges in bringing scientific advances to dizzy patients.}, journal = {Ann N Y Acad Sci}, school = {Upper Austria University of Applied Sciences, Linz, Austria. thomas.haslwanter@fh-linz.at}, year = {2009}, volume = {1164}, pages = {309--315}, url = {http://dx.doi.org/10.1111/j.1749-6632.2008.03716.x}, doi = {https://doi.org/10.1111/j.1749-6632.2008.03716.x} }
Haslwanter, T., Straumann, D., Hepp, K., Hess, B.J. and Henn, V.	Smooth pursuit eye movements obey Listing's law in the monkey. [Abstract] [BibTeX]	1991	Exp Brain Res Vol. 87(2), pp. 470-472School: Neurology Department, University Hospital, Zürich, Switzerland.	article
Abstract: We have tested Listing's law in the monkey using the dual search coil technique to record 3-dimensional eye positions during smooth pursuit and during spontaneous eye movements in the light. Our results indicate that during smooth pursuit the eye positions obey Listing's law with a least the same accuracy as during spontaneous eye movements or during periods of fixations.
BibTeX: @article{Haslwanter1991, author = {T. Haslwanter and D. Straumann and K. Hepp and B. J. Hess and V. Henn}, title = {Smooth pursuit eye movements obey Listing's law in the monkey.}, journal = {Exp Brain Res}, school = {Neurology Department, University Hospital, Zürich, Switzerland.}, year = {1991}, volume = {87}, number = {2}, pages = {470--472} }
Haslwanter, T., Straumann, D., Hess, B.J. and Henn, V.	Static roll and pitch in the monkey: shift and rotation of Listing's plane. [Abstract] [BibTeX]	1992	Vision Res Vol. 32(7), pp. 1341-1348School: Neurology Department, University Hospital, Zürich, Switzerland.	article
Abstract: In three rhesus monkeys three-dimensional eye positions were measured with the dual search coil technique. Recordings of spontaneous eye movements were made in the light and in the dark, with the monkeys in different static roll or pitch positions. Eye positions were expressed as rotation vectors. In all static positions eye rotation vectors were confined to a plane, i.e. Listing's plane was conserved. Tilt about the roll axis shifted the plane along this axis, i.e. a constant torsional component was added to all eye positions. Tilt about the pitch axis changed the pitch angle of Listing's plane.
BibTeX: @article{Haslwanter1992, author = {T. Haslwanter and D. Straumann and B. J. Hess and V. Henn}, title = {Static roll and pitch in the monkey: shift and rotation of Listing's plane.}, journal = {Vision Res}, school = {Neurology Department, University Hospital, Zürich, Switzerland.}, year = {1992}, volume = {32}, number = {7}, pages = {1341--1348} }
Haslwanter, T., Straumann, D., Hess, B.J. and Henn, V.	Does counterrolling violate Listing's law? [BibTeX]	1992	Ann N Y Acad Sci Vol. 656, pp. 931-932School: Neurology Department, University Hospital, Zürich, Switzerland.	article
BibTeX: @article{Haslwanter1992a, author = {T. Haslwanter and D. Straumann and B. J. Hess and V. Henn}, title = {Does counterrolling violate Listing's law?}, journal = {Ann N Y Acad Sci}, school = {Neurology Department, University Hospital, Zürich, Switzerland.}, year = {1992}, volume = {656}, pages = {931--932} }
Henn, V., Straumann, D., Hess, B.J., Haslwanter, T. and Kawachi, N.	Three-dimensional transformations from vestibular and visual input to oculomotor output. [BibTeX]	1992	Ann N Y Acad Sci Vol. 656, pp. 166-180School: Neurology Department, University Hospital, University of Zürich, Switzerland.	article
BibTeX: @article{Henn1992, author = {V. Henn and D. Straumann and B. J. Hess and T. Haslwanter and N. Kawachi}, title = {Three-dimensional transformations from vestibular and visual input to oculomotor output.}, journal = {Ann N Y Acad Sci}, school = {Neurology Department, University Hospital, University of Zürich, Switzerland.}, year = {1992}, volume = {656}, pages = {166--180} }
Hoerantner, R., Kaltofen, T., Priglinger, S., Fock, C.-M., Buchberger, M. and Haslwanter, T.	Model-based improvements in the treatment of patients with strabismus and axial high myopia. [Abstract] [BibTeX]	2007	Invest Ophthalmol Vis Sci Vol. 48(3), pp. 1133-1138School: Department of Ophthalmology, Krankenhaus der Barmherzigen Schwestern (Good Sisters Hospital), Ried, Austria.	article	DOI URL
Abstract: Eye motility disorders with axial high myopia and an enlarged globe are often characterized by a hypotropia of the affected eye, usually referred to as heavy-eye syndrome. Based on an intuitive interpretation of magnetic resonance (MR) images, the cause of the hypotropia has typically been assigned to the rectus muscles. In this study, the hypothesis that the oblique muscles play an important role in the underlying biomechanical disorder of this type of strabismus was investigated.The hypothesis was tested by (1) a retrospective analysis of surgical results in one patient with unilateral axial high myopia; and (2) MR images of orbital tissues in two further patients with unilateral axial high myopia.MR images demonstrated a pattern of extraocular muscle path displacements similar to those described previously, but also a uniform decrease in the cross-sectional area of the inferior oblique muscles. Computer modeling required decreased inferior oblique contractility in addition to displaced extraocular muscle paths to recreate the observed motility pattern accurately.Patients with axial high myopia regularly show a reduction in the diameter of the inferior oblique. The resultant reduction in muscle-strength is important for the correct explanation of this complex eye movement disorder.
BibTeX: @article{Hoerantner2007a, author = {Robert Hoerantner and Thomas Kaltofen and Siegfried Priglinger and Christian-Michael Fock and Michael Buchberger and Thomas Haslwanter}, title = {Model-based improvements in the treatment of patients with strabismus and axial high myopia.}, journal = {Invest Ophthalmol Vis Sci}, school = {Department of Ophthalmology, Krankenhaus der Barmherzigen Schwestern (Good Sisters Hospital), Ried, Austria.}, year = {2007}, volume = {48}, number = {3}, pages = {1133--1138}, url = {http://dx.doi.org/10.1167/iovs.06-0769}, doi = {https://doi.org/10.1167/iovs.06-0769} }
Hoerantner, R., Priglinger, S. and Haslwanter, T.	Reduction of ocular muscle torque by splitting of the rectus muscle II: technique and results. [Abstract] [BibTeX]	2004	Br J Ophthalmol Vol. 88(11), pp. 1409-1413School: Krankenhaus der Barmherzigen Brüder Linz, Austria.	article	DOI URL
Abstract: To present the results of a new technique that the authors have developed to weaken the extraocular muscles. The biomechanics of this technique, which is termed "Y-split recession," are given in the companion paper.A retrospective study, testing the effects of a new surgical technique on strabismus, nystagmus, and visual acuity. 228 patients (aged 6.8 (SD 6.0) years) with variable angle strabismus and nystagmus were treated by splitting and detaching two rectus muscles, and re-attaching the two halves at an angle of about 65 degrees to each other. Subjects were examined with the usual orthoptic tests immediately after the operation, and up to 96 months later.The operation reduced the strabismus, eliminated or weakened the nystagmus in primary position, and improved binocular vision and the development of visual acuity. Only minor side effects were observed.The Y-split recession can be used to reduce the torque for extraocular rectus muscles, and provides an alternative to "Cuppers Fadenoperation," recession, and similar procedures.
BibTeX: @article{Hoerantner2004, author = {R. Hoerantner and S. Priglinger and T. Haslwanter}, title = {Reduction of ocular muscle torque by splitting of the rectus muscle II: technique and results.}, journal = {Br J Ophthalmol}, school = {Krankenhaus der Barmherzigen Brüder Linz, Austria.}, year = {2004}, volume = {88}, number = {11}, pages = {1409--1413}, url = {http://dx.doi.org/10.1136/bjo.2004.042721}, doi = {https://doi.org/10.1136/bjo.2004.042721} }
Hoerantner, R., Priglinger, S., Koch, M. and Haslwanter, T.	A comparison of two different techniques for oculomotor torque reduction. [Abstract] [BibTeX]	2007	Acta Ophthalmol Scand Vol. 85(7), pp. 734-738School: Department of Ophthalmology, Good Sisters Hospital, Ried, Austria. robert.hoerantner@bhs.at	article	DOI URL
Abstract: To compare the results of two different surgical techniques: 'Cüppers technique', in which the torque of oculomotor rectus muscles is reduced by suturing the muscle to the globe in the posterior half of the globe; and 'Y-split recessions', in which the muscle torque is reduced by Y-splitting the rectus muscles, and reattaching the two halves at an angle to each other.We carried out a retrospective analysis of the outcome of surgery on 100 patients with infantile esotropia.Both techniques show a sufficient reduction of strabismus angle variability, and minimal and maximal strabismus angle.Both techniques achieve satisfactory results. In addition, the Y-split technique allows for accurate control of the muscle torque and requires no access to the posterior half of the eye, which can facilitate the surgical approach. For a reduction in muscle torque, the Y-split recession is a good alternative to the established Cüppers technique.
BibTeX: @article{Hoerantner2007, author = {Robert Hoerantner and Siegfried Priglinger and Martina Koch and Thomas Haslwanter}, title = {A comparison of two different techniques for oculomotor torque reduction.}, journal = {Acta Ophthalmol Scand}, school = {Department of Ophthalmology, Good Sisters Hospital, Ried, Austria. robert.hoerantner@bhs.at}, year = {2007}, volume = {85}, number = {7}, pages = {734--738}, url = {http://dx.doi.org/10.1111/j.1600-0420.2007.00933.x}, doi = {https://doi.org/10.1111/j.1600-0420.2007.00933.x} }
Jaeger, R. and Haslwanter, T.	Otolith responses to dynamical stimuli: results of a numerical investigation. [Abstract] [BibTeX]	2004	Biol Cybern Vol. 90(3), pp. 165-175School: Department of Neurology, University Hospital Zürich, Frauenklinikstrasse 26, 8091 Zürich, Switzerland. rudi_jaeger@web.de	article	DOI URL
Abstract: To investigate the dynamic effects of external forces on the displacement of the otolith membrane and subsequent neuronal responses of otoliths, we performed numerical analyses of otolith membrane displacements. In these studies we included the full geometry of the human otolith maculae, including their 3D curvature. The first part focuses on mechanical aspects of the otolith membrane. While it was found that the mechanical coupling of distant parts of the otolith membrane is only weak, these simulations indicate that curvature may have considerable local effects on displacements. They further suggest that the movements of the otoconia, embedded in the interotoconial matrix, show a resonance in a range between 100 and 2000 Hz. In the second part of the article we also investigate the tonic-phasic responses in the vestibular nerve emanating from hair cells in the striola region. Small head tilts away from head upright position are used. The simulations indicate that the direction of head tilt is coded in characteristic response patterns along the striola.
BibTeX: @article{Jaeger2004, author = {R. Jaeger and T. Haslwanter}, title = {Otolith responses to dynamical stimuli: results of a numerical investigation.}, journal = {Biol Cybern}, school = {Department of Neurology, University Hospital Zürich, Frauenklinikstrasse 26, 8091 Zürich, Switzerland. rudi_jaeger@web.de}, year = {2004}, volume = {90}, number = {3}, pages = {165--175}, url = {http://dx.doi.org/10.1007/s00422-003-0456-0}, doi = {https://doi.org/10.1007/s00422-003-0456-0} }
Jaeger, R., Kondrachuk, A.V. and Haslwanter, T.	The distribution of otolith polarization vectors in mammals: comparison between model predictions and single cell recordings. [Abstract] [BibTeX]	2008	Hear Res Vol. 239(1-2), pp. 12-19School: Department of Theoretical Astrophysics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany. rudijaeger@yahoo.com	article	DOI URL
Abstract: The transformation of head-movements into neural signals represents a multi-stage process. It depends on orientation and movement of the head, the geometry and mechanics of the vestibular sensors, and the ensuing processing of the peripheral vestibular signals. While this process is well understood for the semicircular canals, where each canal transduces the angular velocity in the corresponding canal plane, the contributions of the individual otoliths, our linear acceleration sensors, are still under debate. This is in part due to the complex geometrical structure of the otoliths. To improve our understanding of the otoliths, we have developed a new technique to visualize otolith function: using measured 3D-shapes of human otoliths and the observed 2D patterns of hair cell orientation over the epithelia, morphological polarization vectors are predicted. To visualize the geometric distribution of these vectors, we have created distribution plots which indicate the density of hair cell polarization vectors for the different directions. In many respects, our results closely agree with earlier recordings of polarization vectors of vestibular afferents in squirrel monkeys: for example, hair cells on the saccule do not cover the sagittal plane equally, but show a strong concentration in the dorso-ventral directions. Some discrepancies exist in the density distribution of otolith, which could provide valuable information for future anatomical investigations of the otoliths.
BibTeX: @article{Jaeger2008, author = {R. Jaeger and A. V. Kondrachuk and T. Haslwanter}, title = {The distribution of otolith polarization vectors in mammals: comparison between model predictions and single cell recordings.}, journal = {Hear Res}, school = {Department of Theoretical Astrophysics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany. rudijaeger@yahoo.com}, year = {2008}, volume = {239}, number = {1-2}, pages = {12--19}, url = {http://dx.doi.org/10.1016/j.heares.2008.01.004}, doi = {https://doi.org/10.1016/j.heares.2008.01.004} }
Jaeger, R., Takagi, A. and Haslwanter, T.	Modeling the relation between head orientations and otolith responses in humans. [Abstract] [BibTeX]	2002	Hear Res Vol. 173(1-2), pp. 29-42School: Department of Neurology, University Hospital Tübingen, Hoppe-Seyler-Str. 3, Germany. rudi.jaeger@uni-tuebingen.de	article
Abstract: We have performed a finite element simulation of realistic displacements of otolith membranes by static linear accelerations. The simulations were based on accurate measurements of the surfaces of human utricular and saccular maculae, which indicate a clear curvature of these surfaces. The results show that this curvature, a feature probably found in all mammals, has no effect on the mechanics of the structure as a whole since the elastic coupling in the otolith membrane is insufficient. Hair cell excitations on any place of the macula are only affected by the local orientation of the macula with respect to acceleration. Based on the displacements of the otolith membrane, we also calculated the induced activation patterns on the otolith epithelia. These patterns provide for the first time a complete image of peripheral otolith activity. The individual activation patterns at selected locations on the macula correspond well with single cell recordings of actual peripheral otolith neurons.
BibTeX: @article{Jaeger2002, author = {R. Jaeger and A. Takagi and T. Haslwanter}, title = {Modeling the relation between head orientations and otolith responses in humans.}, journal = {Hear Res}, school = {Department of Neurology, University Hospital Tübingen, Hoppe-Seyler-Str. 3, Germany. rudi.jaeger@uni-tuebingen.de}, year = {2002}, volume = {173}, number = {1-2}, pages = {29--42} }
Jarchow, T., Wirz, M., Haslwanter, T., Dietz, V. and Straumann, D.	Perceived horizontal body position in healthy and paraplegic subjects: effect of centrifugation. [Abstract] [BibTeX]	2003	J Neurophysiol Vol. 90(5), pp. 2973-2977School: Department of Psychology University of Zürich, CH-PO32 Zürich, Switzerland. thomas@jarchow.ch	article	DOI URL
Abstract: The perception of body position is mainly mediated by otolith information and visual cues. It has been shown, however, that proprioceptive sources are also involved. To distinguish between the contributions of the vestibular and nonvisual extra-vestibular information to graviception, we tested the effects of a stimulus that leaves the vestibular input unchanged but modifies the information from sense organs located more caudal along the trunk. This was achieved by bringing subjects into a horizontal ear-down position and rotating them around an earth-vertical axis that coincided with the interaural axis. In this paradigm, through centrifugal force, the stimulation of the vestibular and the putative extravestibular graviceptive organs in the body becomes dissociated. Healthy subjects (n = 14) and paraplegic patients with lesions between T4 and T8 (n = 7) adjusted themselves to the perceived horizontal right-ear down body position under two conditions: one with constant velocity rotation (ROT, velocity =120 degrees /s) around the earth-vertical axis of the turntable, and one without rotation (BASE). Among healthy subjects, the individual differences between BASE and ROT varied widely in both the feet-up or feet-down direction. In contrast, adjustments in paraplegic patients during ROT were always in the feet-down direction compared with BASE. A model with two extravestibular graviceptive sensors could explain our results: one sensor is located rostral to T4, and the other is caudal to T8. A load on the rostral graviceptor is interpreted as a tilt of the body in the feet-up direction and shifts the adjustments of perceived body position feet-down; a load on the caudal receptor is interpreted as a tilt in the feet-down direction and shifts the perceived body position feet-up. During ROT, healthy subjects solve the discrepant inputs of both extravestibular graviceptors in a highly variable manner, while paraplegic subjects show less variability because they are restricted to only the rostral graviceptor.
BibTeX: @article{Jarchow2003, author = {T. Jarchow and M. Wirz and T. Haslwanter and V. Dietz and D. Straumann}, title = {Perceived horizontal body position in healthy and paraplegic subjects: effect of centrifugation.}, journal = {J Neurophysiol}, school = {Department of Psychology University of Zürich, CH-PO32 Zürich, Switzerland. thomas@jarchow.ch}, year = {2003}, volume = {90}, number = {5}, pages = {2973--2977}, url = {http://dx.doi.org/10.1152/jn.01129.2002}, doi = {https://doi.org/10.1152/jn.01129.2002} }
Kapoula, Z., Bernotas, M. and Haslwanter, T.	Listing's plane rotation with convergence: role of disparity, accommodation, and depth perception. [Abstract] [BibTeX]	1999	Exp Brain Res Vol. 126(2), pp. 175-186School: Laboratoire de Physiologie de la Perception et de l'Action, UMR 9950 CNRS-Collège de France, Paris. zk@ccr.jussieu.fr	article
Abstract: Earlier studies have reported temporal rotation of Listing's plane with convergence of the eyes causing torsion, which is dependent on eye elevation. The amount by which the planes rotate differs from study to study. To gain insight into the functional significance of the temporal tilt of Listing's plane for vision, we examined whether the rotation of the plane depends on the visual conditions, namely on the stimuli driving vergence. In different conditions, accommodative vergence, disparity-vergence, combinations of disparity with accommodation or depth perception were used and the resulting rotation of Listing's plane was measured. Our findings show, for the first time, that the relationship between convergence and Listing's-plane temporal rotation depends on the stimuli driving vergence. When the stimulus contains only disparity cues, vergence and Listing's plane rotate immediately and consistently among subjects. Accommodative vergence, the mutual couplings between vergence and accommodation, can influence the orientation of Listing's plane, but they do so in a idiosyncratic way. The largest rotation was elicited by stereograms combining disparity-vergence with depth perception. These findings support the idea of a functional role of Listing's plane rotation for binocular vision, perhaps for depth perception.
BibTeX: @article{Kapoula1999, author = {Z. Kapoula and M. Bernotas and T. Haslwanter}, title = {Listing's plane rotation with convergence: role of disparity, accommodation, and depth perception.}, journal = {Exp Brain Res}, school = {Laboratoire de Physiologie de la Perception et de l'Action, UMR 9950 CNRS-Collège de France, Paris. zk@ccr.jussieu.fr}, year = {1999}, volume = {126}, number = {2}, pages = {175--186} }
Koch, M., Priglinger, S., Hoerantner, R. and Haslwanter, T.	Computer-assisted dosage calculation for strabismus therapy in myopic patients. [Abstract] [BibTeX]	2008	Acta Ophthalmol Vol. 86(1), pp. 53-57School: Department of Ophthalmology, University Hospital Graz, Graz, Austria.	article	DOI URL
Abstract: The published dosage recommendations for the surgical correction of horizontal strabismus in non-myopic patients show large, unexplained differences. For patients with high myopia, the situation becomes even more complex because the increase in the size of the bulb also affects the geometry of the oculomotor muscles. In this study, we wanted to investigate whether computer simulations of the oculomotor plant can be used to find accurate surgical parameters.In a retrospective study, we investigated pre- and postoperative strabismus patterns in 13 patients affected by convergent (seven patients) or divergent (six patients) strabismus and high myopia. Postoperative checks were made 1 day, 1 week, 3 months and 1-6 years after the operation. For each patient, we simulated the presurgical strabismus pattern with SEE++ (see 'Further Information' for manufacturer details), a biomechanical simulation program of the oculomotor plant. The individual results of the simulations were then compared to the measured postoperative strabismus patterns.We found a trend of under-correction in the postoperative situation, resulting in four patients having a large remaining strabismus angle of more than 5 degrees. The computer simulations were able to reproduce this under-correction, and suggested an increase in dosage.We conclude that realistic biomechanical simulations of the oculomotor plant can predict the postoperative result for myopic patients accurately. The results of the computer simulation correlate well with the postoperative outcome of the patient.
BibTeX: @article{Koch2008, author = {Martina Koch and Siegfried Priglinger and Robert Hoerantner and Thomas Haslwanter}, title = {Computer-assisted dosage calculation for strabismus therapy in myopic patients.}, journal = {Acta Ophthalmol}, school = {Department of Ophthalmology, University Hospital Graz, Graz, Austria.}, year = {2008}, volume = {86}, number = {1}, pages = {53--57}, url = {http://dx.doi.org/10.1111/j.1600-0420.2007.00997.x}, doi = {https://doi.org/10.1111/j.1600-0420.2007.00997.x} }
Lin, F.R., Migliaccio, A.A., Haslwanter, T., Minor, L.B. and Carey, J.P.	Angular vestibulo-ocular reflex gains correlate with vertigo control after intratympanic gentamicin treatment for Meniere's disease. [Abstract] [BibTeX]	2005	Ann Otol Rhinol Laryngol Vol. 114(10), pp. 777-785School: Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.	article
Abstract: The objective of our study was to determine whether angular vestibulo-ocular reflex (aVOR) gains correlated with vertigo control after intratympanic gentamicin treatment for Meniere's disease.We conducted a prospective study of 18 subjects with unilateral Meniere's disease treated with intratympanic gentamicin injection and followed all subjects for 1 year. We measured the gain of the aVOR elicited by rapid rotary head thrusts in each of the canal planes for each subject before and after treatment with intratympanic gentamicin by using magnetic search coils to record eye movements.During the follow-up period, 11 subjects ("single-treatment group"; 61%) had control of their vertigo with a single gentamicin injection. The remaining 7 subjects ("multiple-treatment group"; 39%) experienced recurrent vertigo that required a second injection of gentamicin at a mean of 6 months after the first treatment. The 11 subjects in the single-treatment group had significantly greater reduction of labyrinthine function after the first treatment, as measured by change in ipsilateral horizontal canal gain, than did the 7 subjects with vertigo recurrence. Changes in caloric asymmetry did not correlate with vertigo control.Our results suggest that successful treatment of Meniere's disease is closely related to attenuation of semicircular canal function as measured by horizontal canal aVOR gains.
BibTeX: @article{Lin2005, author = {Frank R Lin and Americo A Migliaccio and Thomas Haslwanter and Lloyd B Minor and John P Carey}, title = {Angular vestibulo-ocular reflex gains correlate with vertigo control after intratympanic gentamicin treatment for Meniere's disease.}, journal = {Ann Otol Rhinol Laryngol}, school = {Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.}, year = {2005}, volume = {114}, number = {10}, pages = {777--785} }
Minor, L.B., Haslwanter, T., Straumann, D. and Zee, D.S.	Hyperventilation-induced nystagmus in patients with vestibular schwannoma. [Abstract] [BibTeX]	1999	Neurology Vol. 53(9), pp. 2158-2168School: Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD 21287-0910, USA.	article
Abstract: To analyze the nystagmus evoked by hyperventilation in patients with unilateral vestibular schwannoma and to use this information to predict the effects of hyperventilation on individual ampullary nerves.Three-dimensional scleral search coil eye movement recording techniques were used to record the magnitude and time course of eye movements in six patients with unilateral vestibular schwannoma and hyperventilation-induced nystagmus. The presenting complaints in five of these patients were vertigo or dysequilibrium.The eye movement response to hyperventilation was a "recovery" nystagmus with slow-phase components corresponding to excitation of the affected vestibular nerve. Projection of the eye velocity vector into the plane of the semicircular canals revealed that fibers arising from the ampulla of the horizontal canal were most affected by hyperventilation with lesser activation of fibers to the superior canal and smaller, more variable responses from posterior canal fibers.The three-dimensional characteristics of the nystagmus evoked by hyperventilation in patients with vestibular schwannoma provide insight into the vestibular end organs affected by the tumor and the mechanism responsible for the nystagmus. This finding indicates that hyperventilation resulted in a transient increase in activity from these partially demyelinated axons.
BibTeX: @article{Minor1999, author = {L. B. Minor and T. Haslwanter and D. Straumann and D. S. Zee}, title = {Hyperventilation-induced nystagmus in patients with vestibular schwannoma.}, journal = {Neurology}, school = { Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD 21287-0910, USA.}, year = {1999}, volume = {53}, number = {9}, pages = {2158--2168} }
Moore, S.T., Haslwanter, T., Curthoys, I.S. and Smith, S.T.	A geometric basis for measurement of three-dimensional eye position using image processing. [Abstract] [BibTeX]	1996	Vision Res Vol. 36(3), pp. 445-459School: Department of Electrical Engineering, University of Sydney, NSW, Australia.	article
Abstract: Polar cross correlation is commonly used for determination of ocular torsion from video images, but breaks down at eccentric positions if the spherical geometry of the eye is not considered. We have extended this method to allow three-dimensional eye position measurement over a range of +/- 20 deg by determining the correct projection of the eye onto the image plane of the camera. We also determine the orientation of the camera with respect to the eye, allowing eye position to be represented in appropriate head-fixed coordinates. These algorithms have been validated using both in vitro and in vivo measures of eye position.
BibTeX: @article{Moore1996, author = {S. T. Moore and T. Haslwanter and I. S. Curthoys and S. T. Smith}, title = {A geometric basis for measurement of three-dimensional eye position using image processing.}, journal = {Vision Res}, school = {Department of Electrical Engineering, University of Sydney, NSW, Australia.}, year = {1996}, volume = {36}, number = {3}, pages = {445--459} }
Ong, J.K.Y. and Haslwanter, T.	Measuring torsional eye movements by tracking stable iris features. [Abstract] [BibTeX]	2010	J Neurosci Methods Vol. 192(2), pp. 261-267School: Entwicklungs GmbH, Upper Austria University of Applied Sciences, Garnisonstr 21, 4020 Linz, Austria. james.ong@fh-linz.at	article	DOI URL
Abstract: We propose a new method to measure torsional eye movements from videos taken of the eye. In this method, we track iris features that have been identified as Maximally Stable Volumes. These features, which are stable over time, are dark regions with bright borders that are steep in intensity. The advantage of Maximally Stable Volumes is that they are robust to nonuniform illumination and to large changes in eye and camera position. The method performs well even when the iris is partially occluded by reflections or eyelids, and is faster than cross-correlation. In addition, it is possible to use the method on videos of macaque eyes taken in the infrared, where the iris appears almost featureless.
BibTeX: @article{Ong2010, author = {James K Y Ong and Thomas Haslwanter}, title = {Measuring torsional eye movements by tracking stable iris features.}, journal = {J Neurosci Methods}, school = { Entwicklungs GmbH, Upper Austria University of Applied Sciences, Garnisonstr 21, 4020 Linz, Austria. james.ong@fh-linz.at}, year = {2010}, volume = {192}, number = {2}, pages = {261--267}, url = {http://dx.doi.org/10.1016/j.jneumeth.2010.08.004}, doi = {https://doi.org/10.1016/j.jneumeth.2010.08.004} }
Straumann, D. and Haslwanter, T.	Ocular motor disorders [Abstract] [BibTeX]	2001	Curr Opin Neurol Vol. 14(1), pp. 5-10School: Neurology Department, Zurich University Hospital, Zurich, Switzerland. dominik@neurol.unizh.ch	article
Abstract: Our detailed understanding of the physiology and anatomy of the ocular motor system allows an accurate differential diagnosis of pathological eye movement patterns. This review covers important clinical studies and studies in basic research relevant for the neurologist published during the past year.
BibTeX: @article{Straumann2001, author = {D. Straumann and T. Haslwanter}, title = {Ocular motor disorders}, journal = {Curr Opin Neurol}, school = {Neurology Department, Zurich University Hospital, Zurich, Switzerland. dominik@neurol.unizh.ch}, year = {2001}, volume = {14}, number = {1}, pages = {5--10} }
Straumann, D., Haslwanter, T., Hepp-Reymond, M.C. and Hepp, K.	Listing's law for eye, head and arm movements and their synergistic control. [Abstract] [BibTeX]	1991	Exp Brain Res Vol. 86(1), pp. 209-215School: Neurology Department, University Hospital, Zürich, Switzerland.	article
Abstract: We have recorded eye, head, and upper arm rotations in five healthy human subjects using the three-dimensional search coil technique. Our measurements show that the coordination of eye and head movements during gaze shifts within +/- 25 deg relative to the forward direction is organized by restricting the rotatory trajectories of the two systems to almost parallel planes. These so-called "Listing planes" for eye-in-space and head-in-space rotations are workspace-oriented, not body-fixed. Eye and head trajectories in their respective planes are closely related in direction and amplitude. For pointing or grasping, the rotatory trajectories of the arm are also restricted to a workspace-oriented Listing plane. During visually guided movements, arm follows gaze, and the nine-dimensional rotatory configuration space for eye-head-arm-synergies (three degrees of freedom for each system) is reduced to a two-dimensional plane in the space of quaternion vectors.
BibTeX: @article{Straumann1991, author = {D. Straumann and T. Haslwanter and M. C. Hepp-Reymond and K. Hepp}, title = {Listing's law for eye, head and arm movements and their synergistic control.}, journal = {Exp Brain Res}, school = {Neurology Department, University Hospital, Zürich, Switzerland.}, year = {1991}, volume = {86}, number = {1}, pages = {209--215} }
Straumann, D., Suzuki, M., Henn, V., Hess, B.J. and Haslwanter, T.	Visual suppression of torsional vestibular nystagmus in rhesus monkeys. [Abstract] [BibTeX]	1992	Vision Res Vol. 32(6), pp. 1067-1074School: Neurology Department, University Hospital, Zürich, Switzerland.	article
Abstract: Juvenile rhesus monkeys, placed on a motorized turntable, were rotated at constant velocity and then decelerated about an Earth-vertical axis. The animals were implanted with dual search coils to measure eye movements in three dimensions. By changing the monkey's body position (upright, ear-down, supine), postrotatory nystagmus was elicited in the horizontal, vertical, or torsional direction. Peak slow phase eye velocity and time constant of velocity decay were compared between decelerations in the dark and in the light. In all nystagmus directions, illumination reduced the time constant (Tc) to values around 5 sec. Peak velocity (Vp) was markedly attenuated in the horizontal and vertical directions (around 50%), but the effect of light on Vp in the torsional direction was small (less than 20%). These findings were independent of the velocity step size. Our hypothesis is that the two dynamic components of optokinetic nystagmus, as they interact with postrotatory nystagmus during visual suppression, differ in their dimensionality: the early component (fast component, direct pathway, pursuit system) is mainly activated in the horizontal and vertical directions, while the late component (slow component, indirect pathway, optokinetic system) effectively operates in all three dimensions.
BibTeX: @article{Straumann1992, author = {D. Straumann and M. Suzuki and V. Henn and B. J. Hess and T. Haslwanter}, title = {Visual suppression of torsional vestibular nystagmus in rhesus monkeys.}, journal = {Vision Res}, school = {Neurology Department, University Hospital, Zürich, Switzerland.}, year = {1992}, volume = {32}, number = {6}, pages = {1067--1074} }
Tweed, D., Haslwanter, T. and Fetter, M.	Optimizing gaze control in three dimensions. [Abstract] [BibTeX]	1998	Science Vol. 281(5381), pp. 1363-1366School: Department of Physiology, University of Western Ontario, London, Canada.	article
Abstract: Horizontal and vertical movements of the human eye bring new objects to the center of the visual field, but torsional movements rotate the visual world about its center. Ocular torsion stays near zero during head-fixed gaze shifts, and eye movements to visual targets are thought to be driven by purely horizontal and vertical commands. Here, analysis of eye-head gaze shifts revealed that gaze commands were three-dimensional, with a separate neural control system for torsion. Active torsion optimized gaze control as no two-dimensional system could have, stabilizing the retinal image as quickly as possible when it would otherwise have spun around the fixation point.
BibTeX: @article{Tweed1998, author = {D. Tweed and T. Haslwanter and M. Fetter}, title = {Optimizing gaze control in three dimensions.}, journal = {Science}, school = {Department of Physiology, University of Western Ontario, London, Canada.}, year = {1998}, volume = {281}, number = {5381}, pages = {1363--1366} }
Tweed, D.B., Haslwanter, T.P., Happe, V. and Fetter, M.	Non-commutativity in the brain. [Abstract] [BibTeX]	1999	Nature Vol. 399(6733), pp. 261-263School: Department of Physiology, University of Toronto, Canada.	article	DOI URL
Abstract: In non-commutative algebra, order makes a difference to multiplication, so that a x b not equal to b x a. This feature is necessary for computing rotary motion, because order makes a difference to the combined effect of two rotations. It has therefore been proposed that there are non-commutative operators in the brain circuits that deal with rotations, including motor circuits that steer the eyes, head and limbs, and sensory circuits that handle spatial information. This idea is controversial: studies of eye and head control have revealed behaviours that are consistent with non-commutativity in the brain, but none that clearly rules out all commutative models. Here we demonstrate non-commutative computation in the vestibulo-ocular reflex. We show that subjects rotated in darkness can hold their gaze points stable in space, correctly computing different final eye-position commands when put through the same two rotations in different orders, in a way that is unattainable by any commutative system.
BibTeX: @article{Tweed1999, author = {D. B. Tweed and T. P. Haslwanter and V. Happe and M. Fetter}, title = {Non-commutativity in the brain.}, journal = {Nature}, school = {Department of Physiology, University of Toronto, Canada.}, year = {1999}, volume = {399}, number = {6733}, pages = {261--263}, url = {http://dx.doi.org/10.1038/20441}, doi = {https://doi.org/10.1038/20441} }
Weber, K.P., Landau, K., Palla, A., Haslwanter, T. and Straumann, D.	Ocular rotation axes during dynamic Bielschowsky head-tilt testing in unilateral trochlear nerve palsy. [Abstract] [BibTeX]	2004	Invest Ophthalmol Vis Sci Vol. 45(2), pp. 455-465School: Department of Neurology, Zurich University Hospital, Zurich, Switzerland.	article
Abstract: To explain the positive Bielschowsky head-tilt (BHT) sign in unilateral trochlear nerve palsy (uTNP) by the kinematics of three-dimensional eye rotations.Twelve patients with uTNP monocularly fixed on targets on a Hess screen were oscillated (+/- 35 degrees, 0.3 Hz) about the roll axis on a motorized turntable (dynamic BHT). Three-dimensional eye movements were recorded with dual search coils. Normal data were collected from 11 healthy subjects.The rotation axis of the viewing paretic or unaffected eye was nearly parallel to the line of sight. The rotation axis of the covered fellow eye, however, was tilted inward relative to the other axis. This convergence of axes increased with gaze toward the unaffected side. Over entire cycles of head roll, the rotation axis of either eye remained relatively stable in both the viewing and covered conditions.In patients with uTNP, circular gaze trajectories of the covered paretic or unaffected eye during dynamic BHT are a direct consequence of the nasal deviation of the rotation axis from the line of sight. This, in turn, is a geometrical result of decreased force by the superior oblique muscle (SO) of the covered paretic eye or, according to Hering's law, increased force parallel to the paretic SO in the covered unaffected eye. The horizontal incomitance of rotation axes along horizontal eye positions can be explained by the same mechanism.
BibTeX: @article{Weber2004, author = {Konrad P Weber and Klara Landau and Antonella Palla and Thomas Haslwanter and Dominik Straumann}, title = {Ocular rotation axes during dynamic Bielschowsky head-tilt testing in unilateral trochlear nerve palsy.}, journal = {Invest Ophthalmol Vis Sci}, school = {Department of Neurology, Zurich University Hospital, Zurich, Switzerland.}, year = {2004}, volume = {45}, number = {2}, pages = {455--465} }
Weber, K.P., Palla, A., Landau, K., Haslwanter, T. and Straumann, D.	Incomitance of ocular rotation axes in trochlear nerve palsy. [Abstract] [BibTeX]	2003	Ann N Y Acad Sci Vol. 1004, pp. 347-351School: Department of Neurology, Zurich University Hospital, Zurich, Switzerland.	article
Abstract: Strabismus due to palsy of a single muscle in one eye is always incomitant, which is a consequence of Hering's law of equal innervation. We asked whether this law had similar consequences on the orientation of ocular rotation axes. Patients with unilateral trochlear nerve palsy were oscillated about the nasooccipital (= roll) axis (+/-35 degrees, 0.3 Hz), and monocularly fixed on targets on a head-fixed Hess screen. Both the covered and uncovered eyes were measured with dual search coils. The rotation axis of the covered eye (paretic or healthy) tilted more nasally from the line of sight when gaze was directed toward the side of the healthy eye. The rotation axis of the viewing eye (paretic or healthy), however, remained roughly aligned with the line of sight. We conclude that incomitance due to eye muscle palsy extends to ocular rotation axes during vestibular stimulation.
BibTeX: @article{Weber2003, author = {Konrad P Weber and Antonella Palla and Klara Landau and Thomas Haslwanter and Dominik Straumann}, title = {Incomitance of ocular rotation axes in trochlear nerve palsy.}, journal = {Ann N Y Acad Sci}, school = {Department of Neurology, Zurich University Hospital, Zurich, Switzerland.}, year = {2003}, volume = {1004}, pages = {347--351} }
Yakushin, S.B., Palla, A., Haslwanter, T., Bockisch, C.J. and Straumann, D.	Dependence of adaptation of the human vertical angular vestibulo-ocular reflex on gravity. [Abstract] [BibTeX]	2003	Exp Brain Res Vol. 152(1), pp. 137-142School: Department of Neurology, Mount Sinai School of Medicine, 1 East 100th Street, Box 1135, New York, NY 10029, USA. sergei.yakushin@mssm.edu	article	DOI URL
Abstract: We determined the spatial dependence of adaptive gain changes of the vertical angular vestibulo-ocular reflex (aVOR) on gravity in five human subjects. The gain was decreased for 1 h by sinusoidal oscillation in pitch about a spatial vertical axis in a subject-stationary surround with the head oriented left-side down. Gains were tested by sinusoidal oscillation about a spatial vertical axis while subjects were tilted in 15 degrees increments from left- to right-side down positions through the upright. Changes in gain of the vertical component of the induced eye movements were expressed as a percentage of the preadapted values for the final analysis. Vertical aVOR gain changes were maximal in the position in which the gain had been adapted and declined progressively as subjects were moved from this position. Gain changes were plotted as a function of head orientation and fit with a sine function. The bias level of the fitted sines, i.e., the gravity-independent gain change, was -29+/-10% (SD). The gains varied around this bias as a function of head position by +/-18+/-6%, which were the gravity-dependent gain changes. The gravity-dependent gain changes induced by only 1 h of adaptation persisted, gradually declining over several days. We conclude that there is a component of the vertical aVOR gain change in humans that is dependent on the head orientation in which the gain was adapted, and that this dependence can persist for substantial periods.
BibTeX: @article{Yakushin2003, author = {Sergei B Yakushin and Antonella Palla and Thomas Haslwanter and Christopher J Bockisch and Dominik Straumann}, title = {Dependence of adaptation of the human vertical angular vestibulo-ocular reflex on gravity.}, journal = {Exp Brain Res}, school = {Department of Neurology, Mount Sinai School of Medicine, 1 East 100th Street, Box 1135, New York, NY 10029, USA. sergei.yakushin@mssm.edu}, year = {2003}, volume = {152}, number = {1}, pages = {137--142}, url = {http://dx.doi.org/10.1007/s00221-003-1543-0}, doi = {https://doi.org/10.1007/s00221-003-1543-0} }
Brandner, M., Buchberger, M., Kaltofen, T., Haslwanter, T., Hoerantner, R. and Langmann, A.	Biomechanical analysis of x-pattern exotropia. [Abstract] [BibTeX]	2011	American journal of ophthalmology Vol. 152, pp. 141-146	article	DOI
Abstract: To simulate and check the plausibility of the proposed mechanisms of X-pattern exotropia and to determine the least invasive surgical method that can be used to treat the disorder. Computational supported analysis and retrospective study. The oculomotor model SEE++ was used to simulate the effects of the different causes that have been proposed for the X-phenomenon. In addition, a retrospective study was conducted using preoperative and postoperative measurements of 10 patients with X-pattern exotropia. Eye movements and surgery of these patients were simulated and analyzed statistically. Our computer-based simulations showed that only 1 of the 4 proposed theories can account successfully for the observed X-patterns: an overaction of all 4 oblique muscles can induce divergent exotropia in upgaze and downgaze, and an alteration of horizontal muscles can cause the additional divergence in all gaze positions. The simulation of eye muscle surgery confirmed that a sufficient correction of the divergent deviation in all gazes already can be achieved by a recession and resection of 2 horizontal eye muscles. In case of X-pattern exotropia, recession and resection of 2 horizontal muscles can be used as a first-line therapy, leading to a simplification of the therapy.
BibTeX: @article{Brandner2011, author = {Brandner, Martina and Buchberger, Michael and Kaltofen, Thomas and Haslwanter, Thomas and Hoerantner, Robert and Langmann, Andrea}, title = {Biomechanical analysis of x-pattern exotropia.}, journal = {American journal of ophthalmology}, year = {2011}, volume = {152}, pages = {141--146}, doi = {https://doi.org/10.1016/j.ajo.2011.01.029} }
Büki, B., Platz, M., Haslwanter, T., Jünger, H. and Avan, P.	Results of electrocochleography in Ménière's disease after successful vertigo control by single intratympanic gentamicin injection. [Abstract] [BibTeX]	2011	Audiol Neurootol Vol. 16(1), pp. 49-54School: ENT Department, General Hospital Krems, Krems, Austria. bukibela@hotmail.com	article	DOI URL
Abstract: In the last several years, a promising new approach has been suggested in the therapy of Ménière's disease (MD): the low-dose intratympanic gentamicin therapy. By titrating the desired vestibular inhibition by single injections and infrequent administration, side effects concerning hearing can be held on an acceptably low level, while disease-related symptoms are often successfully eliminated. However, it is still unclear if endolymphatic hydrops actually decreases when the patients become symptom free. In the literature, hydrops is significantly associated with an enhanced ratio of summating potential/action potential (SP/AP). Our aim in this retrospective study was to answer the question if pathologically high SP/AP ratios normalize after successful low-dose intratympanic gentamicin treatment. Twenty-eight patients with MD received one, two or three intratympanic gentamicin injections. These injections inhibited vertigo spells without causing additional hearing loss. SP/AP ratios measured by noninvasive electrocochleography did not improve statistically when patients became symptom free. This indicates that the beneficial effect of gentamicin does not depend on the improvement of SP/AP ratios. Considering the well-established correlation between increased SP/AP and active MD, it thus seems unlikely that gentamicin treatment significantly reduces hydrops.
BibTeX: @article{Bueki2011, author = {Béla Büki and Michael Platz and Thomas Haslwanter and Heinz Jünger and Paul Avan}, title = {Results of electrocochleography in Ménière's disease after successful vertigo control by single intratympanic gentamicin injection.}, journal = {Audiol Neurootol}, school = {ENT Department, General Hospital Krems, Krems, Austria. bukibela@hotmail.com}, year = {2011}, volume = {16}, number = {1}, pages = {49--54}, url = {http://dx.doi.org/10.1159/000312538}, doi = {https://doi.org/10.1159/000312538} }
Ring, M.H., Rabensteiner, D.F., Horwath-Winter, J., Boldin, I., Hörantner, R. and Haslwanter, T.	Introducing a new parameter for the assessment of the tear film lipid layer. [Abstract] [BibTeX]	2012	Investigative ophthalmology & visual science Vol. 53, pp. 6638-6644	article	DOI
Abstract: The differential diagnosis of dry eye syndrome is still a challenging task. The purpose of this study was to understand the relationship between a novel, objective clinical parameter, the "corrected lipid layer stabilization time," and commonly performed clinical tests for dry eye patients. Data were obtained from a prospective clinical study with 59 patients of different subjective severity, as determined with the Ocular Surface Disease Index (OSDI). The dynamics of the tear film lipid layer were made visible through a white light source and were stored digitally. Because the distance between the upper and lower eyelid affects the lipid layer dynamics and varies significantly between subjects, the distance of the eyelids was determined and used to correct the lipid layer stabilization time. The resulting parameter was compared with common clinical procedures. The corrected lipid layer stabilization time has a highly significant correlation with tear film breakup time (Spearman r = -0.485, P < 0.01), Schirmer test without anesthesia (r = -0.431, P < 0.01) and with the Ocular Surface Disease Index (r = 0.498, P < 0.01). It also correlates with the lissamine green staining score (r = 0.379, P < 0.05), but shows no correlation with the osmolarity of the tear film. Without the correction for the eyelid opening, the correlations decrease considerably. These data suggest that the diagnostic value of the lipid layer stabilization time for the assessment of the severity of dry eye syndrome increases considerably when it is corrected by the distance of the eyelids.
BibTeX: @article{Ring2012, author = {Ring, Michael H. and Rabensteiner, Dieter F. and Horwath-Winter, Jutta and Boldin, Ingrid and Hörantner, Robert and Haslwanter, Thomas}, title = {Introducing a new parameter for the assessment of the tear film lipid layer.}, journal = {Investigative ophthalmology & visual science}, year = {2012}, volume = {53}, pages = {6638--6644}, doi = {https://doi.org/10.1167/iovs.12-10257} }
Eibenberger, K., Ring, M. and Haslwanter, T.	Sustained effects for training of smooth pursuit plasticity. [Abstract] [BibTeX]	2012	Experimental brain research Vol. 218, pp. 81-89	article	DOI
Abstract: Maintaining orientation in space is a multisensory process, with the vestibular, visual, auditory and somatosensory systems as inputs. Since the input from each individual system changes, for example due to aging, the central nervous system must continuously adapt to these changes to maintain proper system performance. Changes can also be elicited by targeted modifications of the inputs, or by controlled training of sensory systems. While the effects of adaptation on eye movements elicited by the vestibulo-ocular reflex are well established, modifications of the efficacy of smooth pursuit eye movements are less well understood. We have investigated whether two 6-min training sessions on three subsequent days can induce lasting changes in the open- and closed-loop smooth pursuit performance of healthy, adult subjects. Ten subjects practiced making pursuit eye movements by tracking a target cross which moved quasi-randomly on a computer screen. Smooth pursuit performance was tested with a step-ramp paradigm immediately before and after the training, as well as 5 days after the last training session. Our results show that even such short training sessions can induce significant, lasting improvements in closed-loop smooth pursuit performance if the pursuit system of the subjects is challenged sufficiently during training. Control experiments on ten additional adult subjects who had their pursuit performance tested before and after a 20 min break without visual training confirmed that the pursuit enhancement is due to the visual training and not due to perceptual learning.
BibTeX: @article{Eibenberger2012, author = {Eibenberger, Karin and Ring, Michael and Haslwanter, Thomas}, title = {Sustained effects for training of smooth pursuit plasticity.}, journal = {Experimental brain research}, year = {2012}, volume = {218}, pages = {81--89}, doi = {https://doi.org/10.1007/s00221-012-3009-8} }
Eibenberger, K., Carey, J., Ehtiati, T., Trevino, C., Dolberg, J. and Haslwanter, T.	A novel method of 3D image analysis of high-resolution cone beam CT and multi slice CT for the detection of semicircular canal dehiscence. [Abstract] [BibTeX]	2014	Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology Vol. 35, pp. 329-337	article	DOI
Abstract: We investigated if current-generation computed tomographic (CT) scanners have the resolution required to objectively detect bone structure defects as small as 0.1 mm. In addition, we propose that our method is able to predict a possible dehiscence in a semicircular canal. In semicircular canal dehiscence (SCD), the bone overlying the superior canal (SC) is partially absent, causing vertigo, autophony, hyperacusis or hearing loss. Diagnosis of SCD is typically based on multi-slice computed tomography (MSCT) images combined with the consideration of clinical signs and symptoms. Recent studies have shown that MSCT tends to overestimate the size of dehiscences and may skew the diagnosis towards dehiscence when a thin bone layer remains. Evaluations of CT scans for clinical application are typically observer based. We developed a method of objectively evaluating the resolution of CT scanners. We did this for 2 types of computed tomography: MSCT, and cone beam computed tomography (CBCT), which have been reported to have a higher resolution for temporal bone scans. For the evaluation and comparison of image accuracy between different CT scanners and protocols, we built a bone cement phantom containing small, well-defined structural defects (diameter, 0.1-0.4 mm). These small inhomogeneities could reliably be detected by comparing the variances of radiodensities of a region of interest (i.e., a region containing a hole) with a homogenous region. The Fligner-Killeen test was used to predict the presence or absence of a hole (p ≥ 0.05). For our second goal, that is, to see how this technique could be applied to the detection of a possible dehiscence in a SC, a cadaveric head specimen was used to create an anatomic model for a borderline SCD; the SC was drilled to the point of translucency. After semi-automatically fitting the location of the canal, our variance-based approach allowed a clear, significant detection of the thin remaining bone layer. Our approach of statistical noise analysis on bone cement phantoms allowed us to distinguish real irregularities from measured image noise or reconstruction errors. We have shown that with computed tomography, an approach comparing radiodensity variance in regions of interest is capable of detecting inhomogeneities down to 0.1 mm (p ≤ 0.0001). Our analysis of data from the cadaveric head specimen demonstrates that this approach can be used to objectively detect thin layers of bone overlying an SC. This should provide the basis for using this approach for a semi-automated, objective detection of SCD.
BibTeX: @article{Eibenberger2014, author = {Eibenberger, Karin and Carey, John and Ehtiati, Tina and Trevino, Carolina and Dolberg, James and Haslwanter, Thomas}, title = {A novel method of 3D image analysis of high-resolution cone beam CT and multi slice CT for the detection of semicircular canal dehiscence.}, journal = {Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology}, year = {2014}, volume = {35}, pages = {329--337}, doi = {https://doi.org/10.1097/MAO.0000000000000199} }
Ring, M.H., Rabensteiner, D.F., Horwath-Winter, J., Boldin, I., Schrödl, F., Reitsamer, H. and Haslwanter, T.	Non invasive assessment of the human tear film dynamics. [Abstract] [Comment] [BibTeX]	2015	Annals of anatomy = Anatomischer Anzeiger : official organ of the Anatomische Gesellschaft Vol. 202, pp. 61-70	article	DOI
Abstract: Dry eye disease, or keratoconjunctivitis sicca, is a multifactorial syndrome with altered tear film homeostasis leading to ocular irritations. These alterations cause discomfort and stress for the patient, but only a few objective parameters allow for proper differential diagnosis into different subtypes of this condition. The mostly invasively performed standard assessment procedures for tear film diagnosis are manifold, but often correlate quite poorly with the subjectively reported symptoms. Due to the inherent limitations, e.g. the subjectivity of the commonly performed invasive tests, a number of devices have been developed to assess the human tear film non-invasively. Since the production, delivery, distribution and drainage of the tear film is a dynamic process, we have focused our review on non-invasive methods which are capable of continuous or repetitive observations of the tear film during an inter-blink interval. These dynamic methods include (1) Interferometry, (2) Pattern Projection, (3) Aberrometry, (4) Thermography; and (5) Evaporimetry. These techniques are discussed with respect to their diagnostic value, both for screening and differential diagnostic of Dry Eye Disease. Many of the parameters obtained from these tests have been shown to have the potential to reliably discriminate patients from healthy subjects, especially when the tests are performed automatically and objectively. The differentiation into subtypes based solely on a single, dynamic parameter may not be feasible, but the combination of non-invasively performed procedures may provide good discrimination results.
Comment: review
BibTeX: @article{Ring2015, author = {Ring, M. H. and Rabensteiner, D. F. and Horwath-Winter, J. and Boldin, I. and Schrödl, F. and Reitsamer, H. and Haslwanter, T.}, title = {Non invasive assessment of the human tear film dynamics.}, journal = {Annals of anatomy = Anatomischer Anzeiger : official organ of the Anatomische Gesellschaft}, year = {2015}, volume = {202}, pages = {61--70}, doi = {https://doi.org/10.1016/j.aanat.2015.07.007} }
Eibenberger, K., Eibenberger, B., Roberts, D.C., Haslwanter, T. and Carey, J.P.	A novel and inexpensive digital system for eye movement recordings using magnetic scleral search coils. [Abstract] [BibTeX]	2016	Medical & biological engineering & computing Vol. 54, pp. 421-430	article	DOI
Abstract: After their introduction by Robinson (IEEE Trans Biomed Eng 10:137-145, 1963), magnetic scleral search coils quickly became an accepted standard for precise eye movement recordings. While other techniques such as video-oculography or electro-oculography may be more suitable for routine applications, search coils still provide the best low-noise and low-drift characteristics paired with the highest temporal and spatial resolution. The problem with search coils is that many research laboratories still have their large and expensive coil systems installed and are acquiring eye movement data with old, analog technology. Typically, the number of recording channels is limited and modifications to an existing search coil system can be difficult. We propose a system that allows to retro-fit an existing analog search coil system to become a digital recording system. The system includes digital data acquisition boards and a reference coil as the hardware part, receiver software, and a new calibration method. The circuit design has been kept simple and robust, and the proposed software calibration allows the calibration of a single coil within a few seconds.
BibTeX: @article{Eibenberger2016, author = {Eibenberger, Karin and Eibenberger, Bernhard and Roberts, Dale C. and Haslwanter, Thomas and Carey, John P.}, title = {A novel and inexpensive digital system for eye movement recordings using magnetic scleral search coils.}, journal = {Medical & biological engineering & computing}, year = {2016}, volume = {54}, pages = {421--430}, doi = {https://doi.org/10.1007/s11517-015-1326-3} }
Moore, S., Haslwanter, T., Curthoys, I. and Smith, S.	Measurement of three dimensional eye position using image processing: a geometric approach [Abstract] [BibTeX]	1994	Proceedings of 1st International Conference on Image Processing Vol. 1, pp. 436-440 vol.1	inproceedings	DOI
Abstract: Accurate measurement of 3-dimensional eye position is an important tool in the study of the human oculomotor system. The expense and invasive nature of existing 3-dimensional measurement systems have prompted the development of video-based systems for eye position measurement. Most video systems use some variation of the polar cross correlation method, but this technique produces inaccurate results for the torsional component of eye position if the spherical shape of the eye is not taken into account. We have extended the polar cross correlation technique by considering eye geometry and developing the formulae required to determine the projection of the eye into the image plane for all eye positions. These formulae also allow the representation of 3-dimensional eye position in Fick-angles or as rotation vectors, which are commonly used in oculomotor research.<>
BibTeX: @inproceedings{Moore1994, author = {S.T. Moore and T. Haslwanter and I.S. Curthoys and S.T. Smith}, title = {Measurement of three dimensional eye position using image processing: a geometric approach}, journal = {Proceedings of 1st International Conference on Image Processing}, publisher = {IEEE}, year = {1994}, volume = {1}, pages = {436--440 vol.1}, doi = {https://doi.org/10.1109/ICIP.1994.413351} }
Crema, C., Depari, A., Flammini, A., Sisinni, E., Haslwanter, T. and Salzmann, S.	IMU-based solution for automatic detection and classification of exercises in the fitness scenario [Abstract] [BibTeX]	2017	2017 IEEE Sensors Applications Symposium (SAS), pp. 1-6	inproceedings	DOI
Abstract: Causal relationship between physical activity and prevention of several diseases has been known for some time. Recently, attempts to quantify dose-response relationship between physical activity and health show that automatic tracking and quantification of the exercise efforts not only help in motivating people but improve health conditions as well. However, no commercial devices are available for weight training and calisthenics. This work tries to overcome this limit, exploiting machine learning technique (particularly Linear Discriminant Analysis, LDA) for analyzing data coming from wearable inertial measurement units, (IMUs) and classifying/counting such exercises. Computational requirements are compatible with embedded implementation and reported results confirm the feasibility of the proposed approach, offering an average accuracy in the detection of exercises on the order of 85%.
BibTeX: @inproceedings{Crema2017, author = {C. Crema and A. Depari and A. Flammini and E. Sisinni and T. Haslwanter and S. Salzmann}, title = {IMU-based solution for automatic detection and classification of exercises in the fitness scenario}, journal = {2017 IEEE Sensors Applications Symposium (SAS)}, publisher = {IEEE}, year = {2017}, pages = {1--6}, doi = {https://doi.org/10.1109/SAS.2017.7894068} }
Haslwanter, T. and Moore, S.	A theoretical analysis of three-dimensional eye position measurement using polar cross-correlation [Abstract] [BibTeX]	1995	IEEE Transactions on Biomedical Engineering Vol. 42, pp. 1053-1061	article	DOI
Abstract: Polar cross-correlation is a commonly used technique for determination of torsional eye position from video images. At eccentric eye positions, the projection of the sampling window onto the image plane of the camera is translated and deformed due to the spherical shape of the eyeball. Here, the authors extend the polar cross-correlation technique by developing the formulas required to determine the correct location and shape of the sampling window at all eye positions. These formulas also allow the representation of three-dimensional eye position in Fick-angles, which are commonly used in oculomotor research. A numerical simulation shows the size of the errors in ocular torsion if the spherical geometry of the eye is not considered. Other effects which can affect the accuracy of video-based eye position measurements are also discussed.<>
BibTeX: @article{Haslwanter1995c, author = {T. Haslwanter and S.T. Moore}, title = {A theoretical analysis of three-dimensional eye position measurement using polar cross-correlation}, journal = {IEEE Transactions on Biomedical Engineering}, publisher = {IEEE}, year = {1995}, volume = {42}, pages = {1053--1061}, doi = {https://doi.org/10.1109/10.469371} }
Schreiber, K. and Haslwanter, T.	Improving calibration of 3-D video oculography systems. [Abstract] [BibTeX]	2004	IEEE Trans Biomed Eng Vol. 51(4), pp. 676-679School: School of Optometry, University of California at Berkeley, 360 Minor Hall, Berkeley, CA 94720-2020, USA. schreiber@genista.de	article	DOI URL
Abstract: Eye movement recordings with video-based techniques have become very popular, as long as they are restricted to the horizontal and vertical movements of the eye. Reliable measurement of the torsional component of eye movements, which is especially important in the diagnosis and investigation of pathologies, has remained a coveted goal. One of the main reasons is unresolved technical difficulties in the analysis of video-based images of the eye. Based on simulations, we present solutions to two of the primary problems: a robust and reliable calibration of horizontal and vertical eye movement recordings, and the extraction of suitable iris patterns for the determination of the torsional eye position component.
BibTeX: @article{Schreiber2004, author = {Kai Schreiber and Thomas Haslwanter}, title = {Improving calibration of 3-D video oculography systems.}, journal = {IEEE Trans Biomed Eng}, publisher = {IEEE}, school = {School of Optometry, University of California at Berkeley, 360 Minor Hall, Berkeley, CA 94720-2020, USA. schreiber@genista.de}, year = {2004}, volume = {51}, number = {4}, pages = {676--679}, url = {http://dx.doi.org/10.1109/TBME.2003.821025}, doi = {https://doi.org/10.1109/TBME.2003.821025} }
Haslwanter, T.	Hands-on signal analysis with python [BibTeX]	2021		book
BibTeX: @book{Haslwanter2021, author = {Haslwanter, Thomas}, title = {Hands-on signal analysis with python}, publisher = {Springer}, year = {2021} }
Haslwanter, T.	3D Kinematics [BibTeX]	2018	Vol. 578	book
BibTeX: @book{Haslwanter2018, author = {Haslwanter, Thomas}, title = {3D Kinematics}, publisher = {Springer}, year = {2018}, volume = {578} }
Crema, C., Depari, A., Flammini, A., Sisinni, E., Haslwanter, T. and Salzmann, S.	Characterization of a wearable system for automatic supervision of fitness exercises [BibTeX]	2019	Measurement Vol. 147, pp. 106810	article
BibTeX: @article{Crema2019, author = {Crema, C and Depari, A and Flammini, A and Sisinni, E and Haslwanter , T and Salzmann, S}, title = {Characterization of a wearable system for automatic supervision of fitness exercises}, journal = {Measurement}, publisher = {Elsevier}, year = {2019}, volume = {147}, pages = {106810} }
Hörantner, R., Wolfsgruber, J., Stü rzlinger, G., Ring, M. and Haslwanter, T.	Effect of repetitive visual training in patients with dry age-related macular degeneration [BibTeX]	2021	Spektrum der Augenheilkunde Vol. 35(1), pp. 11-15	article
BibTeX: @article{Hoerantner2021, author = {Hörantner, Robert and Wolfsgruber, Jürgen and Stü rzlinger, Gerald and Ring, Michael and Haslwanter, Thomas}, title = {Effect of repetitive visual training in patients with dry age-related macular degeneration}, journal = {Spektrum der Augenheilkunde}, publisher = {Springer}, year = {2021}, volume = {35}, number = {1}, pages = {11--15} }
Moore, S.T., Curthoys, I.S., Haslwanter, T. and Halmagyi, G.M.	Measuring Three-Dimensional Eye Position Using Image Processing--The VTM System [BibTeX]	2020	Three-dimensional Kinematics of the Eye, Head and Limb Movements, pp. 445-450	inbook
BibTeX: @inbook{Moore2020, author = {Moore, Steven T and Curthoys, Ian S and Haslwanter, Thomas and Halmagyi, G Michael}, title = {Measuring Three-Dimensional Eye Position Using Image Processing--The VTM System}, booktitle = {Three-dimensional Kinematics of the Eye, Head and Limb Movements}, publisher = {Routledge}, year = {2020}, pages = {445--450} }
Baur, E., Bauer, T., Egger, H., Salzmann, S. and Haslwanter, T.	Ein neuer Ansatz für eine sensitive Beinprothese--eine Fallstudie [BibTeX]	2016	Sensorische Rückmeldung mittels umgelagerter sensorischer Nerven aus dem Fußbereich. Orthopädie Technik Vol. 67(7), pp. 62-66	article
BibTeX: @article{Baur2016, author = {Baur, EM and Bauer, T and Egger, H and Salzmann, S and Haslwanter, T}, title = {Ein neuer Ansatz für eine sensitive Beinprothese--eine Fallstudie}, journal = {Sensorische Rückmeldung mittels umgelagerter sensorischer Nerven aus dem Fußbereich. Orthopädie Technik}, year = {2016}, volume = {67}, number = {7}, pages = {62--66} }
Fetter, M., Haslwanter, T., Misslich, H. and Tweed, D.	Three-dimensional kinematics of the eye, head and limb movements [BibTeX]	1997		book
BibTeX: @book{Fetter1997, author = {Fetter, Michael and Haslwanter, Thomas and Misslich, Hubert and Tweed, Douglas}, title = {Three-dimensional kinematics of the eye, head and limb movements}, publisher = {Harwood Academic Publishers}, year = {1997} }
Haslwanter, T.	An introduction to statistics with python [BibTeX]	2016	With applications in the life sciences. Switzerland: Springer International Publishing	book
BibTeX: @book{Haslwanter2016, author = {Haslwanter, Thomas}, title = {An introduction to statistics with python}, journal = {With applications in the life sciences. Switzerland: Springer International Publishing}, publisher = {Springer}, year = {2016} }
Haslwanter, T.	An introduction to statistics with python [BibTeX]	2022		book
BibTeX: @book{Haslwanter2022, author = {Haslwanter, Thomas}, title = {An introduction to statistics with python}, publisher = {Springer}, year = {2022}, edition = {2} }
Haslwanter, T. and Clarke, A.H.	Eye movement measurement: Electro-Oculography and Video-Oculography [BibTeX]	2010	Vestibular and Balance Disorders, pp. 61-80	inbook
BibTeX: @inbook{Haslwanter2010, author = {Haslwanter, Thomas and Clarke, Andrew H.}, title = {Eye movement measurement: Electro-Oculography and Video-Oculography}, booktitle = {Vestibular and Balance Disorders}, publisher = {Elsevier}, year = {2010}, pages = {61-80} }
Salzmann, S., Haslwanter, T., Baur, E., Bauer, T. and Egger, H.	A novel approach for a sensitive prosthetic leg - A case study [Comment] [BibTeX]	2016	OT World, Leipzig	inproceedings
Comment: Lecture Case Study [5812] Abstract [1776]
BibTeX: @inproceedings{, author = {Salzmann, Stefan and Haslwanter, Thomas and Baur, E.M. and Bauer, T. and Egger, Hubert}, title = {A novel approach for a sensitive prosthetic leg - A case study}, booktitle = {OT World, Leipzig}, year = {2016} }
Alber, G., Zoller, P. and Haslwanter, T.	One-photon resonant two-photon excitation of Rydberg series close to threshold [BibTeX]	1988	Journal of the Optical Society of America B Vol. 5(12), pp. 2439-2445	article
BibTeX: @article{Alber1988, author = {Alber, G and Zoller, P and Haslwanter, Th}, title = {One-photon resonant two-photon excitation of Rydberg series close to threshold}, journal = {Journal of the Optical Society of America B}, publisher = {OSA}, year = {1988}, volume = {5}, number = {12}, pages = {2439--2445} }
Haslwanter, T., Ritsch, H., Cooper, J. and Zoller, P.	Laser-noise-induced population fluctuations in two-and three-level systems [BibTeX]	1988	Physical Review A Vol. 38(11), pp. 5652	article
BibTeX: @article{Haslwanter1988a, author = {Haslwanter, Th and Ritsch, H and Cooper, J and Zoller, P}, title = {Laser-noise-induced population fluctuations in two-and three-level systems}, journal = {Physical Review A}, publisher = {APS}, year = {1988}, volume = {38}, number = {11}, pages = {5652} }
Haslwanter, T. and Mlynek, J.	Laser cooling in the center-of-mass system: a proposal for the creation of a monoenergetic atomic beam [BibTeX]	1990	Annalen der Physik Vol. 502(7), pp. 583-590	article
BibTeX: @article{Haslwanter1990, author = {Haslwanter, Th and Mlynek, J}, title = {Laser cooling in the center-of-mass system: a proposal for the creation of a monoenergetic atomic beam}, journal = {Annalen der Physik}, year = {1990}, volume = {502}, number = {7}, pages = {583--590} }