Calibration of sensors for reliable radio telemetry in a prototype flexible wound monitoring device

With the growing financial burden of chronic wound management in clinics and hospitals, it is high time to devise wireless wound monitoring devices to be placed within wound dressing for continuously sensing the wound milieu. Sensors are a vital part of such monitoring system, enabling it to sense and measure variations in wound parameters. This paper describes the calibration, characterization and real-time testing of selected temperature, moisture, and pressure sensors deemed suitable for wound monitoring applications. The sensors were chosen on the basis of small size, non-invasiveness, reliable performance, low power consumption and their suitability for placement within wound dressings. All selected sensors were first individually calibrated and characterized using commercially-available software and measurement tools, they are then collectively interfaced to a custom-designed flexible radio-frequency transmitter device for real-time performance measurement within a clinical-grade wound bandage. Experimental results on a mannequin leg have validated the low-power operation, and reliable sensing and data transmission capabilities. The nominal measurement resolutions obtained for temperature, moisture, and pressure were 0.15. °C, 0.85-5 %RH, and 0.05-0.56. mmHg, respectively.