Mechanical Engineer | Generate Product Development Studio | Jan - Apr 2024
Muscle Recovery
Modular, wearable device tailored for measuring muscle voltage during physical therapy
Project Overview
Project Objective & Key Requirements
The goal was to design a modular wearable electromyography (EMG) device tailored for measuring muscle voltage during physical therapy for ACL injuries. This would help patients and physical therapists track muscle recovery progress. Stated below were some of the mechanical key requirements given to us by the client:
Adjustable fabric band with elegant, user-friendly latching mechanism
Battery enclosure and PCB enclosure housing electronics, buttons, and LCD screen
Design Concept & Process
Initial Design Concept
When I was assigned with the latching mechanism, I looked up latches on google but nothing clicked. I opened my suitcase one day and saw this oval interlocking latch and felt like this would be a good fit for our wearable. I drew out top and bottom views, designed it in OnShape, and printed it. It took multiple attempts, but over time I was able to get a clean fit that felt stable.
One issue with the design was the size and how it fit around the leg. Since it was flat and didn't form to the leg, the ovals would not stay closed, but rather angle up. These short comings were resolved in the next iterations talked about below.
Iterations
Key Innovations & Features
To solve the short comings stated above, I came up with four key innovations and features to solve these problems over 6 different iterations.
Magnetic Latch: Added magnets to improve retention and satisfaction when closing the latch
Ergonomic Curve: Designed clasp to have a curved profile to conform to anatomy of a leg (avg. circumference measured to be 135mm)
Textured Grip: Added grooves to finger placement for easy handling
Directional Arrows: Used extruded arrows to show how to use the latch
With the final versions printed in SLA, a sleek, magnetic, ergonomic latching mechanism came to life!
Outcome & Results
Project Outcomes and Future Improvements
With user testing conducted throughout the design process, Muscle Recovery was able to become a slick, fully functional prototype, ready to go to the next steps for the client. If there was more time, I would have loved to try to design the latch to be manufacturable. This would have meant altering the magnet placement, designing a mold for the part, and much more. In the end, this was one of my first projects where I was able to create multiple iterations and come to a end design that I fell in love with.
