A Review of Processing Techniques for Noninvasive Photoplethysmographic Extraction of Health Parameters
|Xavier Gonsalves1, M. M. Sardeshmukh2
|Related article at Pubmed, Scholar Google|
Phenomena like heart rate (HR), heart rate variability (HRV), respiratory rate (RR), blood pulse pressure, blood glucose concentration and oxyhemoglobin saturation are vital for asserting the physiological state of an individual. Conventional methods used to capture them give good signals but are invasive, expensive and are not portable. The flow of blood below the skin has certain parameters like blood volume, blood velocity, blood pressure and blood flow rate which change over time. These cause changes in the spectra of light transmitted through or reflected form the skin. When capturedusing a video camera and analysed after processing, this light information reveals certain health parameters which include HR, HRV, RR and many others. In this paper, we reviewa few of the new processing methods developed for using this imaging technique called photoplethysmographic imaging in extraction of health information and will suggest improvements that can be applied to them.