Imaging Photoplethysmography in Real-time: Development of a Hardware-Software Complex for Vital Signs Monitoring
Valeriy V. Zaytsev 1, Serguei V. Miridonov 2, Victor A. Kashchenko 3,4,5, Alexei A. Kamshilin 1;
1 Institute of Automation and Control Processes Russian Federation;
2 Optics Department, Centro de Investigación Cientfica y de Educación Superior de Ensenada, 3918 Carretera Tijuana-Ensenada, 22860 Ensenada, Baja California, Mexico ;
3 North-Western District Scientific and Clinical CenterNamed After L.G. Sokolov, FMBA, Saint Petersburg,Russian Federation;
4 Saint Petersburg State University, Saint Petersburg,Russian Federation;
5 Beloostrov Clinic, Vsevolozhsk District, Leningrad Region,Russian Federation;
Abstract
Imaging photoplethysmography (iPPG) is a contactless optical technology enabling tissue perfusion mapping through analysis of spatiotemporal changes in reflected light intensity. The vast majority of existing iPPG systems utilize only video data without synchronization with electrocardiogram (ECG) that limits their diagnostic value. Physiological parameter calculation in such systems relies on optical signal analysis algorithms, leading to significant errors caused by either motion artifacts or illumination variations. We propose a novel approach based on processing of synchronously acquired data of iPPG and ECG, which is promising for peripheral microcirculation assessment.
Unlike existing solutions, our custom-made system achieves synchronization between ECG signals and video streams with millisecond accuracy. The hardware incorporates synchronously operating modules: high-sensitivity ECG module based on an Arduino microcontroller and an integrated circuit for signal amplification and filtering, along with commercially available Daheng Imaging camera featuring external synchronization capability. The software ensures synchronous data acquisition and analysis: iPPG-video is streamed at adjustable frame rate, and ECG signal is sampled at 1 kHz. Synchronization is implemented using a shared clock generator and hardware-triggered interrupt mechanism, guaranteeing high accuracy.
The developed system provides real-time processing and visualization of physiological parameters, including perfusion maps with spatial resolution sufficient for ischemia detection. In this report, we will present the latest results of intraoperative monitoring of perfusion changes during abdominal surgeries, which allow surgeons to promptly assess anastomosis viability and identify early signs of postoperative complications, demonstrating its practical clinical significance. The work is supported by the Russian Science Foundation (grant No. 25-15-00400).
Speaker
Valery V. Zaytsev
Institute of Automation and Control Processes Russian Federation
Russia
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