Project Lead(s): German Comina Bellido
Issue
Foot ulcers have been identified as a precursor in 84% of lower extremity amputations in patients with diabetes.
Due to sensory neuropathy, it is often only after a wound develops that patients recognize they are suffering from complications and are at risk of foot amputation.
Constant monitoring of the feet of patients with diabetes by health workers is unrealistic for many public health systems, because of the intensity of care required. There is a need for a device that can be used by patients to perform daily self-inspection of their feet, to alert them before open wounds appear and to facilitate early management and prevention of amputation.
Solution
This project involved development and testing of an easy-to-use, smartphone-enabled, low-cost, dermal thermometer (TempFast) for early detection of foot ulcerations in patients with diabetes.
In a previous study, an association has been shown between the temperature differences within two symmetrical points on both feet and the probability of an ulcer appearing at one of those points. If that difference is greater than 2.20C on two or more consecutive days, there is a higher probability of an infection and subsequent ulceration.
The system has hardware and software components with the hardware based on 12 infrared temperature sensors and an Arduino mainboard with Bluetooth capability.
An Android application enables the smartphone connection to the hardware, collects temperatures from all sensors, calculates the differences, and gives an alert when the difference between symmetric points on both feet is more that 2.20C.
The system has been tested in 40 patients with diabetes at Hospital Nacional Cayetano Heredia in Lima, Peru, and was compared against a Thermal Imager (Fluke Ti555), an FDA-approved dermal thermometer (TempTouch®) and a commercial colourimetric thermometer, based on liquid crystal (TempStat®).
Outcome
In testing, the TempFast showed advantages over all the compared devices.
In this study, the 40 patients involved also learned the importance of self-monitoring of their feet on a daily basis to avoid future amputations. They also learned that different temperatures of feet at symmetric areas for more than two days increases the probability of infection in those areas.
To date, four TempFast devices have been manufactured.
Mass production of the TempFast device will drop the price to less than $330 CAD. While the team feels there is a global market for the device, a market analysis is required to accurately assess potential for future sales.