Optical extra-body communication using smartphone cameras for human vital sign transmission

This paper presents an optical extra-body communication (OEBC) for the transmission of human vital signs in an optical camera communication link. The primary vital signs, such as pulse rate, respiratory rate, body temperature, blood pressure, and peripheral capillary oxygen saturation, are captured from the patient's body. The proposed OEBC system has body sensors installed on various parts of the body for detecting, processing, and communicating the vital sign data. A light-emitting diode (LED) hub is a 4×4 red, green, and blue (RGB) LED array that acts as a coordinator to collect the vital sign data from the sensors and transmit through an optical link, while an android-based smartphone camera is used as the receiver. The proposed OEBC employs color modulation, which assigns colors to each vital sign data and transmits data based on the RGB color combinations. The experiment and simulation results show that the scheme is able to transmit the vital sign data through the optical link with an acceptable bit error rate value of 1.2×10^-4 at a peak signal-to-noise ratio value of 15 dB. The proposed OEBC can thus facilitate both reliable and convenient health monitoring in hospital environments.