No abstract

Slow and regular breathing can generate beneficial effects on cardiovascular system and reduce stress. Breathing pacer is usually helpful for a user to learn to control breathing and restore an optimal breathing pattern. In this paper, a wearable physiological monitoring system supporting real-time breathing biofeedback is presented. An elastic T-shirt with two inductive bands integrated in the positions of rib cage (RC) and abdomen (AB) is used as a motherboard both for physiological monitoring and respiratory biofeedback. Physiological signals such as RC and AB respiration, electrocardiography (ECG), photoplethysmograph (PPG) and artery pulse wave (APW) can be sampled, stored and transmitted wirelessly. When this system is used in biofeedback applications, respiratory signals are processed in real-time by a peak-detection algorithm to recognize the concurrent breathing pattern. By comparing the actual breathing rate with the guiding breathing rate, an audio biofeedback is generated by playing music audios stored in the Micro-SD card through an MP3 decoder chip VS1053. With this design, multiple functions of physiological monitoring, real-time signal processing and audio biofeedback were integrated in one wearable system. Experiment showed that through audio biofeedback this system can guide the user to practice a slow and regular breathing effectively. Physiological data recorded from a Yoga practitioner during meditation demonstrated the capability of the system to acquire cardiopulmonary physiological data during slow breathing. This system is a useful tool both for breathing biofeedback training and its related scientific researches.