Wearable, portable gel sensor for the simultaneous acquisition of heart-related bio-signals at one point and blood pressure estimation

As human lifespan is extended, interest in healthcare and remote diagnosis is being continuously increased. However, conventional electrodes and sensors used in biology are difficult to use in convenience and portability in new remote medical systems. In particular, products using hydrogels, which are commonly used to measure blood pressure (BP) and electrocardiogram (ECG), rapidly deteriorate performance over time. In addition, a complicate process is required to acquisite more than one biosignal. In this study, wearable, portable, cuffless all-gel-based sensors to acquire the pulsation and ECG were developed, which is simultaneously measured them at a single-site. Poly (vinylidene fluoride-trifluoroethylene) gel and polyvinyl chloride ion gel were used for the pulsation and ECG measurement, respectively. An integrated gel sensor with stretchability and flexibility was fabricated and easily attached to the radial artery position. Then, pulsation and ECG were successfully measured at one point at the same time even after 30 days. After calculating the phase time difference between two signals, the algorithm for BP estimation was demonstrated.