A Review on PPG Compression Techniques and Implementations

Photoplethysmography is a simple, widely used low cost technique to acquire important diagnostic information for assessing significant physiological parameters of the human body based on the amount of light reflected from or absorbed by the body. Photoplethysmogram (PPG) signal is recognized as one of the most powerful signals in the diagnosis of variations in heart rate and pulse rate, changes in blood oxygenation levels etc. With the great advancements in communication, information technology and Internet of Things (IoT), wearable health devices have been extensively used to measure PPG signals in telemedicine, remote health monitoring, ambulatory systems and in several mobile health systems. As these small wearable medical devices are battery operated and resource-constrained, dedicated and efficient compression techniques are required to optimally manage energy and memory requirements, without jeopardizing the relevant clinical morphologies. The paper focuses on the review of the existing PPG compression techniques, type of the compression used, the basic implementation and a comparative analysis of these techniques, which could help choose a suitable technique for specific applications.