Without an aid, it is impossible for individuals with congenital upper limb differences or arm amputations to drum. Current prostheses for drumming are either expensive or relatively ineffective. Drummers require precise and minute motor control when using a drumstick to vary the speed, volume, and rhythm of their drumming. This makes designing a prosthesis that adapts to all drum playing rather challenging. As someone who played piano and violin since childhood, I value the happiness that music brings and wanted to open doors for amputees to play musical instruments as well.

Design and prototype an affordable mechanical prosthesis for individuals with transradial (forearm) amputations under Professor Alice Agogino in a team of five M.Eng. students and one Ph.D. student. Test the accuracy of the device and compare it to the accuracy of other available drumming prostheses.

Designer Dominic Siguang Ma created a free, open source drumming prosthesis for anyone with a 3D printer to make: one downloads the files, 3D prints the parts, then assembles it with a few screws and other materials easily purchasable at a local hardware store. Since this was the only affordable drumming prosthesis on the market at the time, it would be the direct competitor to our drumming prosthesis and therefore the most relevant benchmark device. Below are pictures of the Paradiddle prosthesis model and our recreation of it.

Each group member brainstormed ideas for our prosthesis. Below are my sketches.

Ultimately, we decided to create a body-powered prosthesis: to change the bounciness of the drumstick, the user would squeeze their shoulder blades together or loosen their shoulders. The stiffness/bounciness variability was surprisingly effective, and we were pleased with the results.

To test the efficacy of our solution, we had users drum following certain rhythms in the following ways:

   • Normally, using just their hands (if they have both hands)

   • With a rigid stick attached to their arm (to mimic the no-bounce scenario)

   • With the paradiddle prosthesis

   • With our body-powered prosthesis

We collected the data using a drum pad sensor (shown in the image above) and analyzed the data in MATLAB, comparing the user drum beats to the ideal drum beats that we had requested them to play. Unsurprisingly, hand drumming was the most accurate, and the rigid stick device was the least accurate (it could not even perform all the specified drum techniques). The paradiddle and our body-powered prosthesis were comparably accurate. However, the bounciness (stiffness) of our body-powered prosthesis was easier to vary while playing.