Contactless blood perfusion assessment of the free flap in breast reconstruction surgery
Remote photoplethysmography proved useful as a non-contact method for estimating physiological data from different parts of the body. Recent studies have mainly focused on the face region for extraction of blood pulsation signal. In this paper, we have demonstrated the feasibility of non-contact remote photoplethysmography in the monitoring of free flap tissue. An experimental study was conducted, where video recordings of free flaps are obtained during breast reconstruction surgery for 8 patients. The hemoglobin absorption rate of the free flap is closely related to signal-to-noise ratio (SNR) values extracted from free flap pulsation signal during surgery. Obtained results show significantly lower SNR values when the free flap is disconnected from the blood supply compared to the SNR values when the flap is intact or after successful blood supply establishment. This method shows potential as a convenient, non-invasive and reliable tool in post-operative microvascular free flap monitoring.