Pulse Waveforms Monitoring Using Supercapacitive Sensing

Abstract

There is a recent boost of interest in wearable, flexible sensors, and devices for non-invasive monitoring of physiological parameters. Among such flexible sensors, considerable research has been appointed towards flexible pressure sensors. These pressure sensors can detect large and small deformations suitable for applications ranging from e-skin to detecting tiny pulse waveforms from the neck and wrist artery. In order to realize a sensor capable of pressure sensing targeting numerous applications, the recent sensors should have high sensitivity with an extended pressure range, fast response time, and a high signal-to-noise ratio. Pulse waveforms are important cardiovascular biomarkers that bear essential information about cardiovascular health. In order to visualize and extract meaningful information from the pulse waveforms, acquiring high-quality pulse waveforms is the prerequisite. However, building highly sensitive pressure sensors is still challenging while maintaining the sensitivity with a broad pressure sensing range. Targeting these issues, this study presents a facile and cost-effective approach to realize a capacitive pressure sensor based on a supercapacitive sensing mechanism. The sensor could achieve high sensitivity of 2.9kPa-1 with a broad and linear range of around 100kPa. Besides, the sensor has a fast response time of 0.2s and negligible hysteresis. The sensor showed no performance degradation after 5000 cycles. In order to show the practicality, the sensor was used to acquire pulse waveforms from wrist and neck arteries under different conditions. The excellent performance of the sensor was observed as the sensor could detect detailed pulse waveforms under all circumstances. The detailed results will be discussed during the presentation.