quentin mease hospital
prosthetic design

an accessible prosthetic finger design

A research project with an amputee patient, occupational therapists, and design partner.
Project PARA-FINGER was about creating an affordable prosthetic for patients in lower income brackets. Most prosthetic devices use materials which increase the price of the prosthetic,, making it unaffordable to most amputees, PARA-FINGER was designed to be a rigid and strong prosthetic using 3D printing as a means of greatly reducing the cost without sacrificing rigidity.

field research:
patient profile

design goals
Through its structure, topology, and materials, PARA-FINGER had to be a strong sturdy design in order to be functional. For PARA-FINGER to be successfully integrated into Ms. Santos’ life, it needed to be lightweight and unobtrusive.For PARA-FINGER to be a prosthetic that could help Ms. Santos and others in need, it had to be affordable through its choice of materials.
ms. santos
Ms. Santos is a middle-aged woman and amputee, missing the middle and distal digits of her pinky, ring, and middle fingers on her right hand.

main design iterations

main iteration mk.1
The first iteration in our design process, MK.1 utilized a traditional configuration of a 4-bar linkage mechanism.

The main purpose of this iteration was to test the sizing of the ring piece, which was discovered to be too large.

We also conducted strength testing and realized we would need to dramatically increase thicknesses of multiple components.

A study of ergonomic measurements were taken so we could refine the positioning & location of the prosthetic on Ms. Santos’ hand.
main iteration mk.2
The first successful iteration when testing with Ms. Santos.

Includes a unique 3 layer configuration for the mechanism.

The main issue with this iteration was that it made too much contact with Ms. Santos’ stumps, which caused uncomfortable abrasion.

Furthermore it caused too much abrasion with Ms. Santos’ knuckles as well.
main iteration mk.3
The most successful iteration, 70% functionality rating from occupational therapist.

Didn’t cause abrasion of Ms. Santos’ stumps or her knuckles

With this iteration visual weight had to be increased, making the design heavier.

This was due to the required geometry of our 4-bar linkage mechanism being placed above the knuckle and requiring the height of the knuckle piece to be increased. This would allow for us to achive a full functional motion of travel.

main iteration mk.4

a process of refinement
The final version of PARA-FINGER was the result of more months of refining. I realized through specific thickening and reducing of material in certain orientations, a much slimmer, yet strong and rigid design could be achieved.
reducing visual weight
My goal through this project, and specifically on my end of the project, has ben to make PARA-FINGER as slim as possible through the design of each part and choice of materials. This way, PARA-FINGER can become a more usable prosthetic device which patients will want to integrate into their daily lives.