Abstract
The frequency of ocular microtremor (OMT) is related to the functional status of the brain stem, and thus OMT may be useful in the diagnosis and management of brain stem disorders. The paper discusses the design of an OMT measurement system and reports quantitative specifications for three portable systems. All systems use a piezo-electric element as the transducer, which measures the displacement of the sclera during eye rotations. The systems differ in the manner in which the signal is recorded. All systems can detect eye movements corresponding to displacements of the sclera ranging from 12 to over 3000 nm. The frequency responses of all systems are flat (<2 dB deviation from peak response) between 20 and 150 Hz. The phase response shows deviations (<π) at the extremes of this range, but qualitative comparison of input and measured signals demonstrates that phase distortion is not excessive. Thus all systems are acceptable for clinical studies involving OMT.
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Abakumova, L. Y., Shakanovich, A. R. andThomas, J. G. (1975) An investigation of the correlation between abnormal patterns of OMT and an abnormal pupil reflex in neurological patients.J. Neurol. Sci.,26, 469–518.
Adler, F. H. andFliegelman, F. (1934) Influence of fixation on the visual acuity.Arch. Ophthal.,12, 475–483.
Bengi, H. andThomas, J. G. (1968a) Fixation tremor in relation to eyeball muscle mechanics.Nature,217, 773–774.
Bengi, H. andThomas, J. G. (1968b) Three electronic methods for recording ocular tremor.Med. & Biol. Eng.,6, 171–178.
Bengi, H. andThomas, J. G. (1973) Studies on human ocular tremor. InPerspectives in biomedical engineering.Kenedi R. M. (Ed.) Macmillan, London, 281–292.
Brown, F. G. andFletcher, R. (1990)Glaucoma in optometric practice. Blackwell Scientific Publications, London.
Carpenter, R. H. S. (1988)Movements of the eyes, 2nd edn. Pion Ltd., London.
Coakley, D. andThomas, J. G. (1977) The ocular microtremor record as a potential procedure for establishing brain death.J. Neurol. Sci.,31, 199–205.
Coakley, D. andThomas, J. G. (1979) Ocular microtremor: A neurogenic phenomenon.Electromyogr. Clin. Neurophysiol.,19, 325–328.
Coakley, D., Williams, R. andMorris, J. (1979) Minute eye movement during sleep.Electroencephalogr. Clin. Neurophysiol.,47, 126–131.
Coakley, D. (1983)Minute eye movement and brain stem function. CRC Press, Boca Raton.
Ditchburn, R. W. (1955) Eye movements in relation to retinal action.Opt. Acta,1, 171–176.
Ditchburn, R. W. (1973)Eye movements and visual perception. Clarendon Press, Oxford, 381.
Edelhauser, H. F., van Horn, D. L. andRecords, R. E. (1985) Cornea and sclera. InBiomedical foundations of ophthalmology, Vol. 2.Duane, T. D. andJaeger, E. A. (Eds.), Harper & Row, Philadelphia, Chap. 4
Eizenman, M., Frecker, R. C. andHallett, P. E. (1984) Precise non-contacting measurement of eye movements using the corneal reflex.Vision Res.,24, 167–174.
Eizenman, M., Hallett, P. E. andFrecker, R. C. (1985) Power spectra for ocular drift and tremor. —Ibid.,25, 1635–1640.
Geddes L. A. andBaker, L. E. (1989)Principles of applied biomedical instrumentation, 3rd edn. John Wiley & Sons, New York.
Golda, V., Petr, R., Cermak, F., Rozsival, V. andSverak, J. (1981) Ocular microtremor and the level of vigilance.Sb. Ved. Pr. Lek. Fak. karlovy Univ. Hradci. Kralove,24, 77–83.
Hood, J. L. (1990) Tape recording. InAudio electronics reference book.Sinclair, I. R. (Ed.) BSB Professional Books, Oxford.
IFSECN Proceedings (1978) EEG information standards.Electroencephalogr, Clin. Neurophysiol.,45, 144.
International Commission on Radiological Protection (1991)1990 recommendations of the International Commission on Radiological Protection. ICRP Publication 60, Pergamon Press, Oxford.
International Electrotechnical Commission (1979)Safety of medical electrical equipment Part 1 General requirements. IEC Publication 601-1, IEC, Switzerland.
Kedem, B. (1986) Spectral analysis and discriminations by zerocrossings.Proc. IEEE,74, 1477–1493.
Kondraske, G. V. (1986) A noncontacting human tremor sensor and measurement system.IEEE Trans.,IM-35, 201–206.
Kriss, A. (1983) Setting up an evoked potential (EP) laboratory. InEvoked potentials in clinical testing.Halliday, A. M. (Ed.), Churchill Livingstone, Edinburgh.
Krupin, T. (1988)Manual of glaucoma: Diagnosis and management. Churchill Livingstone, New York.
Lynn, P. A. (1989)Introduction to analysis and processing of signals. Macmillan Education, London.
Metting van Rijn, A. C., Peper, A. andGrimbergen, C. A. (1990) High-quality recording of bioelectric events. Part 1 Interference reduction, theory and practice.Med. & Biol. Eng. & Comput.,28, 389–397.
Michalik, M. (1983) Der okular Mikrotremor—ein Indikator für den funktionellen Zustand des Hirnstammus.Psychiatr. Neurol. Med. Psychol. Beih. 29, 196–204.
Michalik, M. (1987) Spektralanalysen des okularen mikrotremors bei hirns trammfunktionsstorungen.EEG-EMG,18, 20–26.
Nagington, J., Sutehall, G. M. andWhipp, P. (1983) Tonometer disinfection and viruses.Br. J. Ophahalmol.,67, 674–676.
Pallis, C. (1983)ABC of brain stem death. Br. Med. J., London.
Pintelon, R. (1990) Phase correction of linear time invariant systems with digital all-pass filters.IEEE Trans.,IM-39, 324–330.
Ratliff, F. andRiggs, L. A. (1950) Involuntary motions of the eye during monocular fixation.J. Exp. Psychol.,40, 687–701.
Reilly, E. L. (1987) EEG recording and operation of the apparatus. InElectroencephalography, basic principles, clinical applications and related fields.Niedermeyer, E. andLopes Da Silva, F. (Eds.), Urban & Schwartzenberg, Baltimore, 57–77.
Riggs, L. A. andRatliff, F. (1951) Visual acuity and the normal tremor of the eyes.Science,114, 17–18.
Riggs, L. A., Armington, J. C. andRatliff, F. (1954) Motions of the retinal image during fixation.J. Opt. Soc. Am.,44, 315–321.
Shakanovich, A. R. andThomas, J. G. (1977) Microtremor of the eyes of comatose patients.Electroencephalogr. Clin. Neurophysiol.,42, 117–119.
Smits, J. G. (1984) Equivalent circuit forend-loaded piezoelectric bimorph actuators.Ferroelectrics,60, 141–148.
Tortora, G. J. andAnagnostakos, N. P. (1990)Principles of anatomy and physiology, 6th edn. Harper and Row, New York.
van Randeraat, J. andSetterington, R. E. (1974)Piezoelectric Ceramics. Elcoma Technical Publications Dept., Eindhoven.
Yarbus, A. L. (1967)Eye movements and vision. Plenum Press, New York.
Young, L. R. andSheena, D. (1975) Survey of eye movement recording methods.Behav Res. Methods & Instrum.,7, 397–429.
Young, L. R. (1988) Eye movement measurement techniques. InEncyclopedia of medical devices and instrumentation, Vol. 4,Webster, J. G. (Ed.) John Wiley & Sons, New York, 1259–1269.
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Sheahan, N.F., Coakley, D., Hegarty, F. et al. Ocular microtremor measurement system: Design and performance. Med. Biol. Eng. Comput. 31, 205–212 (1993). https://doi.org/10.1007/BF02458038
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DOI: https://doi.org/10.1007/BF02458038