Comparison of high-speed videokeratoscopy and ultrasound distance sensing for measuring the longitudinal corneal apex movements


Autoria(s): Kowalska, Malgorzata A.; Kasprzak, Henryk; Iskander, Robert
Data(s)

2009

Resumo

Two different methods to measure binocular longitudinal corneal apex movements were synchronously applied. High-speed videokeratoscopy at a sampling frequency of 15 Hz and a customdesigned ultrasound distance sensor at 100 Hz were used for the left and the right eye, respectively. Four healthy subjects participated in the study. Simultaneously, cardiac electric cycle (ECG) was registered for each subject at 100 Hz. Each measurement took 20 s. Subjects were asked to suppress blinking during the measurements. A rigid headrest and a bite-bar were used to minimize undesirable head movements. Time, frequency and time-frequency representations of the acquired signals were obtained to establish their temporal and spectral contents. Coherence analysis was used to estimate the correlation between the measured signals. The results showed close correlation between both corneal apex movements and the cardiopulmonary system. Unraveling these relationships could lead to better understanding of interactions between ocular biomechanics and vision. The advantages and disadvantages of the two methods in the context of measuring longitudinal movements of the corneal apex are outlined.

Identificador

http://eprints.qut.edu.au/31095/

Publicador

Blackwell Publishing

Relação

DOI:10.1111/j.1475-1313.2009.00648.x

Kowalska, Malgorzata A., Kasprzak, Henryk, & Iskander, Robert (2009) Comparison of high-speed videokeratoscopy and ultrasound distance sensing for measuring the longitudinal corneal apex movements. Ophthalmic And Physiological Optics, 29, pp. 227-234.

Direitos

Copyright 2009 Wiley Interscience

Fonte

Faculty of Health; Institute of Health and Biomedical Innovation; School of Optometry & Vision Science

Palavras-Chave #Cardiopulmonary system #Coherence function #Distance Measurement #Dynamic Corneal Topography
Tipo

Journal Article