A Wearable Bracelet for Simultaneous Monitoring of Transcutaneous Carbon Dioxide and Pulse Rates

Daily monitoring of psychological parameters, encompassing chemical and physical signals, has become increasingly valuable for the management of chronic diseases. Among various vital signs, carbon dioxide exchange and pulse rate (PR) serve as critical indicators for the comprehensive assessment of the cardiopulmonary system. However, simultaneous monitoring of these chemical and physical signals in a nonintrusive manner is challenging. This study presents a wearable bracelet that enables simultaneous monitoring of transcutaneous carbon dioxide (TcCO 2 ) and PR using a nanomaterials-modified lensless CMOS imager. The proposed bracelet exhibits exceptional sensitivity, selectivity, and anti-humidity interference in TcCO 2 detection, and achieves reliable tracking of TcCO 2 and PR fluctuations induced by daily activities, demonstrating great potential in the comprehensive assessment of cardiopulmonary system. In addition, the proposed compact imaging approach is multiplexed and extensible, providing a promising sensing platform for the future development of multifunctional wearable devices.