Exploring solutions for finger tremor patients

Abstract

This report presents an explorative study in finding solutions for finger tremor patients diagnosed with Essential Tremor (ET). Tremors restrict patients from performing delicate movements, creating difficulty in daily activities, such as drinking, writing, cooking or eating. Besides the challenges in performing tasks, social anxiety often occurs and negatively influences social life.

Currently, solutions for people with tremors are limited. STIL recognized this need and designed an orthosis for people with wrist tremors. The solution from STIL is an orthosis called the BEAM. The BEAM mechanically suppresses the wrist flexion extension and forearm pronation-supination tremors. Evaluation of the current BEAM concluded that wrist tremors are successfully suppressed, but tremors situated mainly in the fingers need additional stabilization. This study aims to design a functional wearable that mechanically suppresses finger tremors.

To better understand finger tremors, the project provides information on hand anatomy, the current market for finger wearables, and a video analysis of previous tests from STIL. The research found that there is limited knowledge about finger tremors and available wearables specifically designed for them. In user tests STIL saw many people with tremors also deal with a finger tremor, people can benefit from a finger wearable . In addition, the design scope research aimed to identify the specific needs and desires of people with finger tremors. The focus is on discovering a healthy and comfortable balance between freedom of movement and suppression of the fingers. The research conducted with three participant showed that the thumb, index, and middle fingers at the MCP (third joint from top of finger) and PIP (second joint from top of finger) joints need to be suppressed and that participants desire an inconspicuous and open design.

The ideation phase exists out of multiple iterations. The basis of the ideation is a meeting with an expert in Emerging Materials, a morphological card, and brainstorming with the team of STIL. The basis concluded in four promising design directions, which could suppress the finger tremor: wires with springs, gel/air damping, elastic bands, and splints with different stiffnesses. Prototypes were built to research and test the four directions. Finally, the most interesting concepts are elastic bands and splints with different stiffness. The elastic bands give a counterforce to the fingers by pulling them backward. The silicone splints in a glove are made of silicone with spring steel which lies on the fingers.

The working principle and ergonomics of the elastic bands and silicone splints have been validated in patient research. The results showed that the silicone splints were better in terms of performance and comfort, while the elastic bands were preferred in terms of design and adaptability. The final concept used the working principle of silicone splints. The final iteration focuses on appearance, ergonomics, usability, and connection to the BEAM.

In conclusion, this report provides a foundation for STIL to further develop a wearable solution for people with finger tremors. The working principle of using silicone splints to suppress finger tremors is promising, but additional iterations are necessary.