Yu.V. Kadochkin – Master, Department of Medical and Technical Information Technologies (BMT-2), 

Bauman Moscow State Technical University

P.V. Luzhnov – Ph.D. (Eng.), Associate Professor, Department of Medical 

and Technical Information Technologies (BMT-2), 

Bauman Moscow State Technical University

E-mail: petervl@yandex.ru

A.P. Nikolaev – Dr.Sc. (Med.), Professor, Head of Department of Medical and Technical Management (BMT-4),  Bauman Moscow State Technical University

E-mail: apnikolaev@yandex.ru

E.N. Iomdina – Dr. Sc. (Biol.), Professor, Leader Research Scientist, 

Moscow Helmholtz Research Institute of Eye Diseases

Statement of the problem. The general analysis of a blood flow is necessary for receiving fuller information on blood supply of an eye and formation on this basis of effective diagnostic inferences. Rheoophthalmography (ROG) method addition with the photoplethysmography (PPG) channel will raise its accuracy and self-descriptiveness verified. 

Aim of the work – development of PPG sensor design, capable of working together with a transpalpebral ROG channel, and also researching of motion artefacts in the PPG channel at its use on an eyelid. 

Results. The group of researches consists of 6 volunteers who are not suffering by cardiovascular diseases. Were chosen PPG in red and in infra-red channel. The registered signals have been processed by means of spectral analysis. Computing of a signal spectrum was realized in MATLAB software environment by means of discrete Fourier transformation algorithm. The ratio a signal/noise was computed for every calculated value of power spectrum. The frequency band of a useful signal and the frequency band of artifacts were defined in the following way. The central frequency of pulse wave frequency band was defined as the average frequency of heart rate computed with using PPG signal of 2-nd stage of measurement (measurements during rest, without artifacts). The central frequency of motion artifacts frequency band is equal to the frequency of artifacts. Power in every of frequency bands was calculated as value of the amplitudes sum in the area with the boundary lines matching values of boundary lines in chosen areas of frequencies. Then the analysis and statistical manipulation of results was carried out. Results of research have shown that PPG in the infra-red range is less subjected to influence of motion artifacts, than PPG in a red range. 

Practical significance. Thus registrated signals in the conditions of vertical oscillations of the artifacts possess lower signal/noise ratio than at the signals whose registration was carried out in the conditions of horizontal motion artifacts. It can be explained by change of a skin layers thickness in which PPG signal is carried out. The PPG signal of the infra-red range both in case of vertical, and in case of horizontal motion artifacts shows higher value of ratio a signal/noise types.

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