Novel Flexible Wearable Sensor Materials and Signal Processing for Vital Sign and Human Activity Monitoring

Abstract

Advances in flexible electronic materials and smart textile, along with broad availability of smart phones, cloud and wireless systems have empowered the wearable technologies for significant impact on future of digital and personalized healthcare as well as consumer electronics. However, challenges related to lack of accuracy, reliability, high power consumption, rigid or bulky form factor and difficulty in interpretation of data have limited their wide-scale application in these potential areas. As an important solution to these challenges, we present latest advances in novel flexible electronic materials and sensors that enable comfortable and conformable body interaction and potential for invisible integration within daily apparel. Advances in novel flexible materials and sensors are described for wearable monitoring of human vital signs including, body temperature, respiratory rate and heart rate, muscle movements and activity. We then present advances in signal processing focusing on motion and noise artifact removal, data mining and aspects of sensor fusion relevant to future clinical applications of wearable technology.

Hydrogel‐Enabled Transfer‐Printing of Conducting Polymer Films for Soft Organic Bioelectronics

“…These unique properties of PEDOT:PSS have enabled the development of numerous advanced organic electronic devices including solar cells, light‐emitting diodes, transistors, memristors, and artificial synapses for neuromorphic computing . Recently, with the rising research trend in flexible electronics, which have offered unprecedented opportunities in revolutionizing our understanding of electronic devices, PEDOT:PSS has extended its important role in developing various flexible organic electronic devices such as organic electrochemical transistors (OECTs), an emerging tool for biosensing . However, directly manipulating and patterning PEDOT:PSS thin films on flexible substrates remain challenging because of difficulties in obtaining uniform and continuous films on soft substrates such as plastics and elastomers due to their hydrophobic nature .…”

Experimental Characterization of Inkjet-Printed Stretchable Circuits for Wearable Sensor Applications

“…The first method is based on the addition of conductive fillers such as carbon nanotubes, carbon black or metallic powders to non-conductive elastomers. The second method allows the patterning of conductive lines on rubber substrates using various photolithography techniques; such as depositing conductive lines on a prefabricated wavy stretchable substrate [22], depositing conductive lines on an axially pre-stretched substrate to produce line buckling after release [23], and depositing tortuous conductive lines on a stretchable substrate [24,25,26]. …”

A Multi-Parametric Wearable System to Monitor Neck Movements and Respiratory Frequency of Computer Workers

“…Two FBG sensors were encapsulated into a flexible matrix to have a robust system, and to improve the adherence of the sensing elements to the skin and the compliance with the neck movements. FBGs were chosen because of their lightweight, small size, high metrological performances, and immunity to electromagnetic interference [21,[40][41][42][43][44][45][46]. A pilot study on five volunteers aimed at assessing the proposed wearable system in following FE and axial rotation (AR) of the neck, and f R .…”