Assessing the DSR Ankle

NCT ID: NCT05955378

Last Updated: 2025-07-01

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 5 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-08-22
• Study Completion Date: 2024-12-19

Brief Summary

This research is being done to conduct a preliminary investigation into a new prosthetic microprocessor controlled (MPC) ankle, called the Damping, Stiffness, and Repositioning (DSR) ankle. The DSR ankle is a new design to support a person while they walk on both even and uneven ground, as well as with bending the ankle for safe foot clearance while a person takes a step. In particular, in this study we are interested in seeing how this type of new device may benefit people who are rated as a K2-level ambulator.

Detailed Description

Synchro Motion, LLC developed a novel MPC ankle. Because of its unique actuation scheme, the prosthesis can behave as: (1) a lockable conformal damper, (2) a variable set-point spring, and (3) an actively repositionable joint.

The investigators therefore refer to the device as the damping, stiffness, and repositioning (DSR) ankle. The DSR ankle is small, lightweight, quiet, and runs for multiple days on a single charge. No other commercially available prosthesis combines this set of features. It will be shown in preliminary work that the features of the DSR ankle can increase toe clearance in swing, reduce the time-to-foot-flat after heel strike, and improve weight bearing symmetry when standing on slopes for K3 Individuals with Lower Limb Amputation (ILLAs). These biomechanical functions have all been linked to improved safety and stability, which leads the investigators to hypothesize that the DSR ankle may provide benefits to K2 ILLAs as well.

The main purpose of this research is to determine the ways in which the DSR ankle may be adapted to provide benefits specifically to ILLAs who use their prosthesis at the K2 level. For purposes of the Phase I work, the development and assessment will be performed exclusively with K2 ILLAs in order to provide an opportunity to implement any necessary refinements to the DSR ankle to ensure optimal K2 performance. The remainder of the research is to quantify the effectiveness of the DSR ankle as compared to a predicate non-MPC ankle in improving performance for K2 ILLAs.

Conditions

Amputation; Limb Deficiencies

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

DSR Ankle

The DSR Ankle is a novel microprocessor-controlled ankle prosthesis that is able to provide enhanced mobility and stability to individuals with lower limb amputation. It interfaces to the user by attaching to their socket via an industry-standard pyramid connector.

Group Type: EXPERIMENTAL

DSR Ankle

Intervention Type: DEVICE

This is the experimental ankle component used in the overall prosthetic intervention.

Predicate Ankle

The predicate ankle is the user's prescribed prosthesis worn for the activities of daily living.

Group Type: ACTIVE_COMPARATOR

Predicate Ankle

Intervention Type: DEVICE

This is the participant's prescribed ankle/foot complex used in the overall prosthetic intervention.

Interventions

DSR Ankle

This is the experimental ankle component used in the overall prosthetic intervention.

Intervention Type: DEVICE

Predicate Ankle

This is the participant's prescribed ankle/foot complex used in the overall prosthetic intervention.

Intervention Type: DEVICE

Other Intervention Names

The Damping, Stiffness and Repositioning Ankle; Daily Use Ankle

Eligibility Criteria

Inclusion Criteria

1. Adults aged 18-89 years

2. Patients who have a unilateral transtibial amputation who are able to use a prosthesis and who currently use a passive, non-MPC prosthesis

3. K2 level ambulators

Exclusion Criteria

1. Pregnant women

2. Children (<18 years old)

3. Prisoners or institutionalized individuals

4. Individuals who have the inability to give informed consent

5. Participants unable to walk for 2 minutes without an assistive device

6. Participants with complicating health conditions that interfere with the study

7. Inability to read and understand the English language. As this is a pilot study with a small sample size, it is prohibitive to translate Study documents to other languages as recruitment will be from a sample of convenience.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 89 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Shirley Ryan AbilityLab

OTHER

Sponsor Role: collaborator

Synchro Motion LLC

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Shirley Ryan AbilityLab

Chicago, Illinois, United States

Countries

United States

Provided Documents

Document Type: Study Protocol, Statistical Analysis Plan, and Informed Consent Form

View Document

Other Identifiers

STU00217993

Identifier Type: -

Identifier Source: org_study_id