Optical Smart Wearable Sensor: Pulse Waveform and Pulse Rate Monitoring With a Flexible Loop Optic-Microfiber

A highly sensitive, wearable, flexible fiber-optic sensor for monitoring pulse waveforms and pulse rates is proposed and demonstrated, obtained by making a loop microfiber and encapsulating it in a polydimethylsiloxane (PDMS) film. This proposed sensor offers a dramatic improvement in sensitivity, achieving 5.85 V/kPa in the low pressure range of 0–0.15 N, while enabling weak pressure sensing, high flexibility and high sensitivity. The wearable sensor is demonstrated fast response/recovery time (approx. 0.25 s) and good repeatability in the load-unload test. In addition, the experimental verification of the sensing wrist pulse in different states of different human bodies has been carried out, and the experimental results show that the pulse detecting experiments based on this sensor are successful, which clearly displays the pulse waveforms in different states (prolonged periods of rest, 200 times high leg raises and resting for 20 min after exercising). The sensor is also able to promptly monitor whether there is any abnormality in the pulse rate after exercise, thus reducing the risk of disease. This such sensor offers the exciting prospects for personalized and non-invasive healthcare solutions, and as the technology continues to evolve and mature, the potential for this wearable sensor to improve healthcare outcomes and enhance an individual's quality of life will become increasingly apparent.