Battery-Free, Wireless, Ionic Liquid Sensor Arrays to Monitor Pressure and Temperature of Patients in Bed and Wheelchair

Repositioning is a common guideline for the prevention of pressure injuries of bedridden or wheelchair patients. However, frequent repositioning could deteriorate the quality of patient's life and induce secondary injuries. This paper introduces a method for continuous multi-site monitoring of pressure and temperature distribution from strategically deployed sensor arrays at skin interfaces via battery-free, wireless ionic liquid pressure sensors. The wirelessly delivered power enables stable operation of the ionic liquid pressure sensor, which shows enhanced sensitivity, negligible hysteresis, high linearity and cyclic stability over relevant pressure range. The experimental investigations of the wireless devices, verified by numerical simulation of the key responses, support capabilities for real-time, continuous, long-term monitoring of the pressure and temperature distribution from multiple sensor arrays. Clinical trials on two hemiplegic patients confined on bed or wheelchair integrated with the system demonstrate the feasibility of sensor arrays for a decrease in pressure and temperature distribution under minimal repositioning.

Automated summary

This paper presents a method for continuous multi-site monitoring of pressure and temperature distribution using wireless ionic liquid pressure sensors on bedridden or wheelchair-bound patients. The wirelessly delivered power enables stable operation of the sensors, which exhibit enhanced sensitivity, negligible hysteresis, high linearity, and cyclic stability. Experimental investigations and numerical simulations support the real-time, continuous, long-term monitoring capabilities of the sensor arrays. Clinical trials on two hemiplegic patients demonstrate the feasibility of reducing pressure and temperature distribution with minimal repositioning using the sensor arrays.