Wearable heart rate variability analysis system based on ionic conductive hydrogels

Developing a wearable device that can continuously and reliably detect and evaluate heart rate variability (HRV) parameters is critical for the diabetic population with cardiac autonomic neuropathy (CAN). In this work, we proposed a zwitterionic conducting hydrogel that enabled a reliable and comfortable wearable device for the evaluation and detection of the autonomic nervous system (ANS). The hydrogel can achieve a strain of 2003 %, an electrical conductivity of 190 mS/m, and is capable of adhering to a variety of materials, including wood, plastic, and glass. Through the excellent performance of the hydrogel, we can continuously monitor the electrocardiogram (ECG) signals of healthy people and diabetic patients in the resting state for 5 min and analyze the HRV parameters in the time domain, frequency domain and nonlinear condition. The results showed that compared with healthy people, the HRV parameters of diabetic patients were decreased. Finally, the obtained state of the ANS is displayed through a self-designed mini-program on WeChat. In conclusion, by combining the proposed hydrogel with wearable devices, real-time monitoring of CAN in diabetic patients is expected to be achieved and shows great potential in personalized human-computer interaction.