A highly accurate flexible sensor system for human blood pressure and heart rate monitoring based on graphene/sponge

The development of wearable devices has shown tremendous dynamism, which places greater demands on the accuracy and consistency of sensors. This work reports a flexible sensing system for human health monitoring of parameters such as human pulse waveform, blood pressure and heart rate. The signal acquisition part is a vertically structured piezoresistive micro-pressure flexible sensor. To ensure accuracy, the sensors are filled with melamine sponge covered by graphene nanoconductive materials as the conductive layer, and ecoflex material acts as the flexible substrate. The flexible sensors fabricated under the 3D printing mold-assisted method exhibited high accuracy, good repeatability and remarkable response to micro-pressure. However, when used for human pulse signal measurement, the sensors are affected by unavoidable interference. In order to collect human health data accurately, signal acquisition and processing systems were constructed. The system allows for the accurate acquisition of human pulse signals, accompanied by the function of non-invasive, real-time and continuous detection of human blood pressure heart rate parameters. By comparing with an Omron blood pressure monitor, the blood pressure heart rate index error of the flexible sensing system does not exceed 3%.