A Novel Prosthetic Ankle Joint with Swing Phase Dorsiflexion and Terrain Adaptation

PROJECT SUMMARY
Objective
The objective of this proposal is to develop a novel ankle prosthesis prototype, named the Passive
Dorsiflexing Ankle Prosthesis (PDAP), into a clinically effective commercial product by validating it experimentally
and adding all terrain capabilities to transform it into the PDAP Terrain. The novel prosthesis is the first of its kind
to enable reduced fall risk and pain for prosthesis users without introducing the tradeoffs associated with other
more complex design approaches used in mechatronic or hydraulic ankles.
Significance
The clinical significance of the PDAP Terrain is threefold:
1. Ankle prostheses are relevant to all individuals with lower limb amputations above the level of the foot
(estimated at almost 1,000,000 in the US alone).
2. The PDAP Terrain is designed to reduce falls and pain, which are primary concerns among lower limb
prosthesis users, create millions of dollars in healthcare costs annually, and reduce quality of life for patients.
3. The PDAP Terrain represents an opportunity for rapid clinical adoption due to its classification as a Class I
medical device that is 510(k) exempt. Reimbursement codes already exist that will allow the PDAP Terrain
to be fit to both low and high mobility patients.
Innovation
The PDAP Terrain is a unique prosthetic ankle capable of swing phase dorsiflexion, stance phase energy
storage and return, and multiaxial terrain adaptation. It is the only passive prosthetic ankle that can achieve these
distinct behaviors, creating a unique place for this device in today's marketplace. Relative to mechatronic ankles
that provide comparable stance and swing behaviors, the PDAP Terrain provides its function in a smaller, lighter,
and simpler package and does not require batteries or associated charging. Other prosthetic manufacturers have
only been able to provide these features with the use of mechatronic devices due to the significant technological
hurdle of providing them passively. Little Room Innovations has cleared this hurdle with its novel mechanism.
Approach
Our approach is to optimize the PDAP Terrain and test it with prosthesis users. We propose 4 aims: 1) refine
the dorsiflexion mechanism for clinical readiness, 2) conduct a take-home study on the optimized design, 3)
integrate terrain adaptation, and 4) conduct an in-lab study of the PDAP Terrain to assess its added value.
This approach is carefully designed to produce a clinic-ready prosthesis with scientifically justified
biomechanical value. Once the refinement of the PDAP Terrain and its clinical value are fully vetted through the
aims of this proposal, the result will be a path to market that is clearly defined and low risk.

Grant Number: 1R44HD117546-01
NIH Institute/Center: NIH
Principal Investigator: Harrison Bartlett