New Markers of Thermoregulation in the Human Body Assessed Using Imaging Photoplethysmography
Natalia P. Podolyan1, Irina A. Mizeva2, Anastasiia V. Sakovskaia3, Maria E. Vasilieva4, Oleg V. Mamontov5, Viktor A. Kashchenko4, Roman V. Romashko1 and Aleksey A. Kamshilin1; 1Institute of Automation and Control Processes FEB RAS, Vladivostok, Russia;
2Institute of Continuous Media Mechanics, Perm, Russia;
3Institute of Therapy and Instrumental Diagnostics, Pacific State Medical University, Vladivostok, Russia;
4North-Western District Scientific and Clinical Center Named After L.G. Sokolov, FMBA, Saint Petersburg, Russia;
5Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russia
Abstract
In this work, a quantitative assessment of the blood flow response to heating of the forearm skin was performed using imaging photoplethysmography (IPPG). The heated area was illuminated by green incoherent light. The skin temperature in the heater area was monitored using a computer-controlled device. The video recording of the heating area was made by a monochrome camera synchronously with the subject’s electrocardiogram (ECG). The innovative approach of correlating IPPG and ECG signals, coupled with a novel algorithm for stabilizing images, has greatly enhanced the ability to detect the signal resulting from blood flow pulsation, despite the presence of unavoidable motion artifacts. This approach made it possible to estimate quantitatively and with high reliability the changes in the amplitude of pulsations (APC) and the arrival time of the pulse wave (PAT) in each cardiac cycle. A significant (up to 23 times) increase in the BPA parameter was found after local heating, accompanied by a significant (up to 80 ms) decrease in PAT in the heated area. Heating led to an increase in APC and a simultaneous decrease in PAT in all subjects (n=67). We assume that the observed dependencies can be explained by changes in hemodynamics caused by the activity of arteriovenous anastomoses. Therefore, the APC and PAT parameters make it possible to quantify the functional reserve of peripheral vessels and serve as new markers of blood flow changes during thermoregulation. The work is supported by the Russian Science Foundation (grant No. 25-15-00400).
Speaker
Natalia Podolyan
Institute of Automation and Control Processes FEB RAS
Russia
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