Open-source Adaptive Under-actuated Prosthetic Hand (Independent-Research)

• Since March 2020, I've been working alongside my job to bring a myoelectric prosthetic solution for transradial amputees to the commercial market. I was inspired to work on this project after my interaction with an orthopaedic surgeon from AIMS Rishikesh who was working with Jaipur Foot and visited our campus during my college final year. Although there are many high-tech devices available, the expense of these devices makes it exceedingly difficult for people to afford them, and even for those who can afford them, the abandonment rate remains very high. My goal was to develop a device which could address both these issues.

 Problem 1 (Low user satisfaction and difficult to use)

All the prosthetic devices available in the market provide a variety of grip patterns for different tasks. The most common selling point for these devices is the number of grip patterns these devices can provide, but more grip patterns also make the device difficult to use as switching between these grip patterns before every activity is cumbersome.

Problem 2 (High Cost)

The advanced prosthetic devices available in the market are very costly. The cheapest ones among these devices start anywhere around 4000-5000 $ and most amputees are not able to afford these devices. And even those who can afford these devices do not get user satisfaction for the price they are charged for.

 Developed Device (AU-Hand):

The device was developed with the aim of solving both the above-mentioned problems, and the developed device is having following features:

• The developed device uses a novel under-actuation mechanism that uses a  single actuator to synergistically move all the finger digits to adapt according to the object's shape. The user just needs to control the strength of the EMG input signal from the residual muscle to control the applied grasping force.

• The device is having a bistable adduction-abduction thumb that can be quickly switched according to the grip pattern required.

• The fingers digits of the device have a novel tendon sheath-inspired design that adapts according to the grasping strength required.

• The device is majorly 3D printed and costs one order less than the commercially available cheapest EMG-controlled prosthetics.

The work has been published online on  GitHub and the research has been submitted to IEEE-TMRB. Please find the preprint of the research article by clicking on the link below.