Abstract
Congenital nystagmus (CN) is an ocular-motor disorder characterised by involuntary, conjugated ocular oscillations, that can arise since the first months of life. Pathogenesis of congenital nystagmus is still under investigation. In general, CN patients show a considerable decrease of their visual acuity: image fixation on the retina is disturbed by nystagmus continuous oscillations, mainly horizontal. However, image stabilisation is still achieved during the short periods in which eye velocity slows down while the target image is placed onto the fovea (called foveation intervals). To quantify the extent of nystagmus, eye movement recording are routinely employed, allowing physicians to extract and analyse nystagmus main features such as shape, amplitude and frequency. Using eye movement recording, it is also possible to compute estimated visual acuity predictors: analytical functions which estimates expected visual acuity using signal features such as foveation time and foveation position variability. Use of those functions add information to typical visual acuity measurement (e.g. Landolt C test) and could be a support for therapy planning or monitoring. This study focus on robust detection of CN patients' foveations. Specifically, it proposes a method to recognize the exact signal tracts in which a subject foveates, This paper also analyses foveation sequences. About 50 eyemovement recordings, either infrared-oculographic or electrooculographic, from different CN subjects were acquired. Results suggest that an exponential interpolation for the slow phases of nystagmus could improve foveation time computing and reduce influence of breaking saccades and data noise. Moreover a concise description of foveation sequence variability can be achieved using non-fitting splines.
Original language | English |
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Title of host publication | 4th European Conference of the International Federation for Medical and Biological Engineering |
Subtitle of host publication | ECIFMBE 2008 23–27 November 2008 Antwerp, Belgium |
Editors | Jos Vander Sloten, Pascal Verdonck, Marc Nyssen, Jens Haueisen |
Place of Publication | Berlin (DE) |
Publisher | Springer |
Pages | 364-367 |
Number of pages | 4 |
ISBN (Electronic) | 978-3-540-89208-3 |
ISBN (Print) | 978-3-540-89207-6 |
DOIs | |
Publication status | Published - 2008 |
Event | 4th European Conference of the International Federation for Medical and Biological Engineering - Antwerp, Belgium Duration: 23 Nov 2008 → 27 Nov 2008 |
Publication series
Name | IFMBE proceedings |
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Publisher | Springer |
Volume | 22 |
ISSN (Print) | 1680-0737 |
Conference
Conference | 4th European Conference of the International Federation for Medical and Biological Engineering |
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Abbreviated title | ECIFMBE 2008 |
Country | Belgium |
City | Antwerp |
Period | 23/11/08 → 27/11/08 |
Fingerprint
Keywords
- congenital nystagmus
- eye movement signal processing
- foveation
- interpolation
Cite this
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Detection of foveation windows and analysis of foveation sequences in congenital nystagmus. / Pasquariello, Giulio; Cesarelli, Mario; Bifulco, Paolo; Fratini, Antonio; La Gatta, Antonio; Boccuzzi, Domenico.
4th European Conference of the International Federation for Medical and Biological Engineering: ECIFMBE 2008 23–27 November 2008 Antwerp, Belgium. ed. / Jos Vander Sloten; Pascal Verdonck; Marc Nyssen; Jens Haueisen. Berlin (DE) : Springer, 2008. p. 364-367 (IFMBE proceedings; Vol. 22).Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
TY - GEN
T1 - Detection of foveation windows and analysis of foveation sequences in congenital nystagmus
AU - Pasquariello, Giulio
AU - Cesarelli, Mario
AU - Bifulco, Paolo
AU - Fratini, Antonio
AU - La Gatta, Antonio
AU - Boccuzzi, Domenico
PY - 2008
Y1 - 2008
N2 - Congenital nystagmus (CN) is an ocular-motor disorder characterised by involuntary, conjugated ocular oscillations, that can arise since the first months of life. Pathogenesis of congenital nystagmus is still under investigation. In general, CN patients show a considerable decrease of their visual acuity: image fixation on the retina is disturbed by nystagmus continuous oscillations, mainly horizontal. However, image stabilisation is still achieved during the short periods in which eye velocity slows down while the target image is placed onto the fovea (called foveation intervals). To quantify the extent of nystagmus, eye movement recording are routinely employed, allowing physicians to extract and analyse nystagmus main features such as shape, amplitude and frequency. Using eye movement recording, it is also possible to compute estimated visual acuity predictors: analytical functions which estimates expected visual acuity using signal features such as foveation time and foveation position variability. Use of those functions add information to typical visual acuity measurement (e.g. Landolt C test) and could be a support for therapy planning or monitoring. This study focus on robust detection of CN patients' foveations. Specifically, it proposes a method to recognize the exact signal tracts in which a subject foveates, This paper also analyses foveation sequences. About 50 eyemovement recordings, either infrared-oculographic or electrooculographic, from different CN subjects were acquired. Results suggest that an exponential interpolation for the slow phases of nystagmus could improve foveation time computing and reduce influence of breaking saccades and data noise. Moreover a concise description of foveation sequence variability can be achieved using non-fitting splines.
AB - Congenital nystagmus (CN) is an ocular-motor disorder characterised by involuntary, conjugated ocular oscillations, that can arise since the first months of life. Pathogenesis of congenital nystagmus is still under investigation. In general, CN patients show a considerable decrease of their visual acuity: image fixation on the retina is disturbed by nystagmus continuous oscillations, mainly horizontal. However, image stabilisation is still achieved during the short periods in which eye velocity slows down while the target image is placed onto the fovea (called foveation intervals). To quantify the extent of nystagmus, eye movement recording are routinely employed, allowing physicians to extract and analyse nystagmus main features such as shape, amplitude and frequency. Using eye movement recording, it is also possible to compute estimated visual acuity predictors: analytical functions which estimates expected visual acuity using signal features such as foveation time and foveation position variability. Use of those functions add information to typical visual acuity measurement (e.g. Landolt C test) and could be a support for therapy planning or monitoring. This study focus on robust detection of CN patients' foveations. Specifically, it proposes a method to recognize the exact signal tracts in which a subject foveates, This paper also analyses foveation sequences. About 50 eyemovement recordings, either infrared-oculographic or electrooculographic, from different CN subjects were acquired. Results suggest that an exponential interpolation for the slow phases of nystagmus could improve foveation time computing and reduce influence of breaking saccades and data noise. Moreover a concise description of foveation sequence variability can be achieved using non-fitting splines.
KW - congenital nystagmus
KW - eye movement signal processing
KW - foveation
KW - interpolation
UR - http://www.scopus.com/inward/record.url?scp=70350680137&partnerID=8YFLogxK
UR - http://link.springer.com/chapter/10.1007/978-3-540-89208-3_86
U2 - 10.1007/978-3-540-89208-3_86
DO - 10.1007/978-3-540-89208-3_86
M3 - Conference contribution
AN - SCOPUS:70350680137
SN - 978-3-540-89207-6
T3 - IFMBE proceedings
SP - 364
EP - 367
BT - 4th European Conference of the International Federation for Medical and Biological Engineering
A2 - Vander Sloten, Jos
A2 - Verdonck, Pascal
A2 - Nyssen, Marc
A2 - Haueisen, Jens
PB - Springer
CY - Berlin (DE)
ER -