Abstract

Subject of study. The investigation pertains to the optical systems of medical devices designed for dermatoscopy and capillaroscopy, with a focus on facilitating non-invasive skin and microcirculation diagnostics. The aim of the study is to design an optical system that integrates the visual observation capabilities of a dermatoscope with the essential features of a modern video capillaroscope, namely, capillary blood flow imaging and photoplethysmography. Photoplethysmography is a recording of changes in the amplitude of blood volume fluctuations that occur during filling of capillaries and small vessels, depending on the phase of the cardio cycle. Method. This study discusses the basic principles of the layout of visual and recording channels; formulates the requirements for the spectral range, main optical characteristics, and image quality of the recording channel; and examines the parameters of a sensor for digital image recording. Main results. A principal optical scheme and a modular layout for the device are proposed, followed by simulations and analyses. The study introduces a modular device design and details the recording channel’s optical system design, including aberration analysis, optimization, and image quality evaluation. Practical significance. The synthesis of the newly developed lens components data is pivotal in devising a videocapillaroscopy device layout. This layout is applicable not only to nailfold capillaroscopy (NFC) but also to arbitrary skin area examination, significantly enhancing the diagnostic scope of the video capillaroscopy method.

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