Stroke Patient Recovery Pillow
This project was conducted through the CHARM LAB, the Collaborative Haptics and Robotics in Medicine Lab at Stanford University
Role: Undergraduate Research Assistant, Product Developer
Skills: Design Sketching, Physical Prototyping, Design Communication, Collaborative Research, Product Realization, Arduino
Overview: Developed inflatable pillow measuring displacement of air pressure in order to quantify the physical therapeutic progress of the grip strength in stroke patients
Read more about the project here.
Ideation
The idea for the initial prototype was to create an inflatable hollow silicone carrot that would be used to help recovering stroke patients loosen their chenched hands while simultaneously measuring their progress during the recovery process. The amount of air pressure remaining in the carrot would be measured after it is inserted into the patient’s hand.
My first direction to achieve this goal: designing a carrot with a pneumatic pump and gauge attached to the larger end. A string and a safe, large needle will be attached to the other end. The pump will inflate the carrot, and the gauge will measure the maximum pressure reached by the patient’s grip. The string and dull needle would be used to thread the device into the patient’s hand, as their hands are typically clenched to a point where it can be difficult to place a device into their hand.
Troubleshooting & Second Prototype Proposal
One way the design could be improved would be changing the technique for jamming. In our device, we used a syringe to add or remove air into the balloon. While this technique is great for costs and portability, it would likely be difficult for the patient to change the resistance of the ball by themselves if they are in need of hand rehabilitation. Using another air supply system where the user could change the supply more easily would be more beneficial for our user base.
On top of altering the method of air pressure, some issues with using silicone were appearing. The silicone must be highly elastic in order to allow for enough room for air. Nails can also puncture the material.
The third issue with the prototype is the shape of the device. In order to adequately gauge the pressure of each finger in the stroke patients, the shape of the device must be uniform. Rectangular when flat, and a pillow when inflated.
Prototype 2 Sketch
An inflatable carrot pillow with an airtight balloon surrounded by fabric that would be comfortable for the patient and would allow for friction so that the hand stays in place on the device. There would be two holes: one for inflating the device and one for deflating it A pressure transducer will be attached to the device to gauge the grip strength of the patient.
Final Product
I was very pleased with how the pillow turned out! This project spanned out from January to March of 2020, and I am very thankful to say that we were able to run a handful of patient trials before the initial COVID lockdown took place. This image is taken from the published paper, and provides a clean visual for the inner workings of the mechanism.
However, because of the time this experiment took place, I was unable to take any personal photos of the mechanism. All photos include patients, and I am not allowed to share those here.