Development of a functional prototype of a SMART (Sensor-integrated for Monitoring And Remote Tracking) foot abduction brace for clubfoot treatment: a pre-clinical evaluation

Abstract

Purpose: Recurrences following clubfoot correction by the Ponseti method can be prevented by regular use of a foot abduction brace (FAB) until the child is four to five years old. However, there is a lack of an objective method to measure actual hours of brace usage. The aim was to develop a functional prototype of a SMART (Sensor-integrated for Monitoring And Remote Tracking) clubfoot brace to record accurate brace usage and transmit the data remotely to healthcare providers treating clubfoot.

Methods: A collaborative team of engineers and doctors was formed to investigate various types of sensors and wireless technologies to develop a functional prototype of a SMART brace.

Results: Infrared sensors were used to detect if the feet were placed inside the shoes and magnetic Hall effect sensors to detect that the shoes were latched on to the bar of the existing FAB. Brace usage data were captured by the sensors every 15 minutes and stored locally on a data card. A Bluetooth low energy (BLE)-based wireless transmission system was used to send the data daily from the brace to the remote cloud server via a smartphone application. Accurate brace usage data could be recorded by the sensors and visualized in real time on a web-based application in a pre-clinical setting, demonstrating feasibility in clinical practice.

Conclusion: The low-cost SMART brace prototype that we have developed can accurately measure and remotely transmit brace usage data and has the potential to transform caregivers' behaviour towards brace adherence, which could result in a tangible reduction in recurrence rates.

Keywords: Brace adherence; Clubfoot; Foot abduction brace; Ponseti method; Recurrences; Sensors.

Conflict of interest statement

The authors have declared the following relationships: Dr. Alaric Aroojis received consultancy fees from MiracleFeet as principal investigator for this project. The other authors received part-time fees and reimbursement of incurred expenses from the funds received from the SICOT grant. BETiC has collaborations with the medical device industry on other products.

© 2021. SICOT aisbl.

Figures

Fig. 1

a SMART brace modular attachments fitted on to the bar of the MiracleFeet foot abduction brace (MFAB). b Final prototype of the SMART brace showing modular attachments and shoes attached to the bar of the MFAB

Fig. 2

First iteration of sensor design showing a force-sensitive resistor (FSR) sensors in the sole of the shoe and b magnetic port for data transmission

Fig. 3

Second iteration of sensor design showing a touch sensors on the sole of the shoe and b data recorder and transmitter in the shoe base

Fig. 4

Final iteration of sensor design showing a infrared sensor in the modular attachment and b Hall sensor magnet embedded in the base of the shoe

Fig. 5

Block diagram showing data flow

Fig. 6

a The under surface of the printed circuit board (PCB) showing both the Hall effect and the infrared (IR) sensors. b The top layer of the PCB showing electronics components

Fig. 7

Block diagram of the electronic components for the master module

Fig. 8

Screenshot of data visualization page of the web application showing cumulative number of hours the child has worn the brace, day-wise