The design and evaluation of a personalized 3D-printed hand brace with pressure sensors for enhanced functionality and continuous feedback monitoring

Abstract

Background: In the field of orthoses for the treatment of forearm injuries, there is a growing clinical demand for more precise and individualized health monitoring technologies. The integration of additive manufacturing techniques with wearable electronics has gained significant interest in this field, emerging as a prominent treatment option that aims to address this demand and gradually replacing conventional rehabilitation approaches. While the medical benefits of orthoses are well-established, a significant challenge persists in ensuring patient adherence to suggested usage guidelines.

Objectives: This thesis aims to develop a systematic workflow for providing personalized feedback to patients, with the objective of 1) improving their functional recovery throughout the rehabilitation process, and 2) facilitating patient adherence to their prescribed treatment plan.

Methods: A general workflow for the utilization of wearable electronics inside an orthotic device is proposed. This workflow accounts for the physical interactions between the user and the orthotic device itself. Particularly, an elastomer material was used to fabricate the hand brace with six commercially available force-sensitive sensors and a microcontroller for data processing and integration, into the proposed workflow. Each element of this workflow is discussed with respect to the role that it plays in the treatment of a forearm injury, along with how the data of each sensor can be used as inputs to the designed platform that aims to monitor the patient compliance to the treatment plan. Through an accessible web interface, users can conveniently track their treatment progress, receive real-time feedback on brace usage and monitor wear duration. Concurrently, clinicians can gain access to valuable monitoring capabilities, facilitating data-informed adjustments for personalized care. To validate the effectiveness of the designed 3D-printed hand brace, finite element simulations and experiments were conducted to evaluate the immobilization of the hand brace and study pressure distribution, by applying the brace on a participant’s hand.

Results: Simulation results were compared to those of experiments and demonstrate positive outcomes, affirming the brace's ability to provide support for forearm fractures with 85% immobilization for the hand rotation under wrist movements. The maximum average pressure values observed during experiments were less than 0.3 MPa for wrist flexion and 0.2 MPa for wrist extension.

Conclusion: The proposed method outlines a multistep process that lays the foundation for future advancements in orthopedic brace design and personalized healthcare. It offers an objective means of monitoring patient adherence to forearm treatment methods and allows a trained healthcare worker to 3D-print a brace based on the initial medical diagnosis and subsequently modify the treatment method considering the data captured via platform during the user’s daily activities.