Wireless sensors for continuous, multimodal measurements at the skin interface with lower limb prostheses

Abstract

Precise form-fitting of prosthetic sockets is important for the comfort and well-being of persons with limb amputations. Capabilities for continuous monitoring of pressure and temperature at the skin-prosthesis interface can be valuable in the fitting process and in monitoring for the development of dangerous regions of increased pressure and temperature as limb volume changes during daily activities. Conventional pressure transducers and temperature sensors cannot provide comfortable, irritation-free measurements because of their relatively rigid construction and requirements for wired interfaces to external data acquisition hardware. Here, we introduce a millimeter-scale pressure sensor that adopts a soft, three-dimensional design that integrates into a thin, flexible battery-free, wireless platform with a built-in temperature sensor to allow operation in a noninvasive, imperceptible fashion directly at the skin-prosthesis interface. The sensor system mounts on the surface of the skin of the residual limb, in single or multiple locations of interest. A wireless reader module attached to the outside of the prosthetic socket wirelessly provides power to the sensor and wirelessly receives data from it, for continuous long-range transmission to a standard consumer electronic device such as a smartphone or tablet computer. Characterization of both the sensor and the system, together with theoretical analysis of the key responses, illustrates linear, accurate responses and the ability to address the entire range of relevant pressures and to capture skin temperature accurately, both in a continuous mode. Clinical application in two prosthesis users demonstrates the functionality and feasibility of this soft, wireless system.

Stretchable Capacitive Pressure Sensing Sleeve Deployable onto Catheter Balloons towards Continuous Intra-Abdominal Pressure Monitoring

“…This can transmit the capacitance change wirelessly to a receiver antenna outside the body [ 28 ]. Alternatively, the device could be designed to have a small battery-powered integrated circuit (IC) to collect and transfer data via wireless communication protocols such as WiFi, bluetooth, or near-field communication (NFC) [ 41 ]. However, both of these options have design complications in terms of size, form factor, etc., that need to be explored.…”

Flexible Electronics and Healthcare Applications

“…and pressure of the prosthesis and skin interface of amputee patients under the conditions of standing, sitting and walking, and has the advantages of small hysteresis and high linearity (Kwak et al, 2020).…”

Recent progress in flexible tactile sensor systems: from design to application

“…A multi-mode integrated tactile sensor system that can detect strain, temperature, and gas simultaneously was reported [21] . Wireless tactile sensors were enabled with the development of Bluetooth transmission and near field communication technology [22][23][24] . To extend the application fields, a sensor array was realized to decode the facial strains through machine learning [25] , and a sweat sensor that can detect blood glucose, nicotine, and other health information was developed [26][27][28] .…”