Objective: I set out to redesign the Panasonic Deep Muscle Stimulator (below) in order to make it more ergonomic as a hand tool.

I began by observing a professional, an athletic trainer for the Georgia Tech football team, use the tool on an athlete. I then interviewed him afterward to gain insight on his perspective of the tool. From this research, I built a journey map to identify high and low points of usage.

Next, I researched ways I could apply the study of Human Factors to my redesign and created my findings graphically.

I identified two main areas that caused the biggest issues for the user:

Button Location: the power button is located at the bottom of the tool; in order to turn in on or off, the user must hold the tool with two hands.

Trainer Fatigue: after roughly five minutes of treatment, the trainer's hand gets sore from their dominant hand twisting forward and their non-dominant hand pressing on the tool without any kind of grip.

I sketched six ideas that incorporated a better grip for the dominant hand and that added a grip for the non-dominant hand and then created a concept model for each idea.

Based on feedback from the trainer, I narrowed it down to essentially two ideas, combing A and D.

I 3D printed the two models and gave it to the trainer and fellow designers around me. Based on their feedback, I chose to move forward with model G.

My final design is limited in two ways because of time and money:

Motor: I purchased a low-end motor to keep cost down. Consequently, it cannot withstand much torque.

Battery: ideally, this product would be rechargeable, but a rechargeable battery that would fit well with the design was not in the budget.