Auto Control of Volume Management for Limb Loss

NCT03550118 | Completed Results FDA Device

• 1 other identifier: STUDY00001779
• Study Type: interventional
• Target: 104
• Locations: 1 country
• Sites: 1

Brief Summary

The aim of this research is to create a prosthetic system that will automatically adjust the fit of the socket and create a well-fitting prosthesis for people with leg amputations who experience volume fluctuations when using their prosthesis.

Conditions

Lower Limb Amputation Below Knee (Injury)

Keywords

Prosthetic Socket; Amputee; Adjustable Socket

Outcome Measures

Primary Outcomes (4)

• Change in Limb Volume

  Limb volume fluctuations will be measured in real-time as socket adjustment strategies are tested. This will be accomplished using a portable bioimpedance device with thin sticky electrodes that are placed on the residual limb. Specifically, the change in limb volume will be assessed from a baseline period where no socket adjustments are made to another period within the same test session where socket adjustments are made.

  Change from baseline period (non-adjustment) to test period (adjustment), commonly each 1 hour long and separated by a seated period of approximately 30 minutes.

• Change in Limb Movement

  Limb movement within the socket will be measured as socket adjustment strategies are tested. It will be used as an indicator of how well the socket is fitting (loose, tight, etc). The measurement will be made using an inductance sensor that is placed in the socket which measures the displacement of a sensor patch on the prosthetic liner. Specifically, the change in limb movement will be assessed from a baseline period where no socket adjustments are made to another period within the same test session where socket adjustments are made.

  Change from baseline period (non-adjustment) to test period (adjustment), commonly each 1 hour long and separated by a seated period of approximately 30 minutes.

• Number of Participants With Increase in Limb Fluid Volume After Panel Pull

  Limb volume fluctuations will be measured in real-time as socket adjustment strategies are tested. This will be accomplished using a portable bioimpedance device with thin sticky electrodes that are placed on the residual limb. Specifically, the change in limb volume will be assessed from a baseline period where no socket adjustments are made to another period within the same test session where socket adjustments are made.

  Change from baseline period (non-adjustment) to test period (adjustment), commonly each 1 hour long and separated by a seated period of approximately 30 minutes.

• Integral of Absolute Error to Maintain Set Point

  Clinically acceptable socket volume error as measured by an automatically adjusting prosthetic socket attempting to maintain a set socket volume set point, based on sensed distance (measured in mm).

  Over 30 minutes of controlled use of the auto-adjusting socket

Secondary Outcomes (1)

• Adjustable Socket Mode Preference

  After 3 weeks of use, where each mode was tested for about 1 week

Study Arms (8)

Aim 2 - Adjustable Socket - Researcher Controls

EXPERIMENTAL

An adjustable socket is tested where researchers control the adjustments. This arm focuses on socket size adjustments while walking.

Device: Adjustable socket

Aim 3 - Adjustable Socket - Participant Controls

EXPERIMENTAL

An adjustable socket is tested where the study participant controls the adjustments. This arm focuses on socket size adjustments while walking.

Device: Adjustable socket

Aim 4 - Adjustable Socket - Automatic Controls

EXPERIMENTAL

An adjustable socket is tested where a control system is used to automatically control the adjustments. This arm focuses on socket size adjustments while walking.

Device: Adjustable socket

Aim 6A - Release/Recovery - Researcher Controls

EXPERIMENTAL

An adjustable socket is tested where researchers control the adjustments. This arm focuses on a socket release and recovery mechanism that allows for full or partial doffing of the socket while seated.

Device: Adjustable socket

Aim 6B - Release/Recovery - Participant Controls

EXPERIMENTAL

An adjustable socket is tested where the study participant controls the adjustments. This arm focuses on a socket release and recovery mechanism that allows for full or partial doffing of the socket while seated.

Device: Adjustable socket

Aim 8 - Panel Pull During Resting

EXPERIMENTAL

The purpose of Aim #8 was to determine if vacuum-like action ("panel pull") during resting between periods of activity facilitated limb fluid volume recovery and retention in transtibial prosthesis users. Liner attached to panels.

Device: Adjustable socket

Aim 9 - Panel Pull During Ambulation

EXPERIMENTAL

Extending from the Aim #8 results, we sought to determine in Aim #9 if "vacuum-like" action during ambulation facilitated limb fluid volume recovery and retention. Vacuum-like action was achieved by quickly pulling the panels and liner (liner attached to panels) radially outward during late stance phase and then moving them back to their original position during early swing.

Device: Adjustable socket

Aim 10 - Adjustable Socket Out of Lab Testing

EXPERIMENTAL

Participants took the investigational device home in one of three test modes. In the first mode, the panels were in a "locked" flush position, similar to their traditional prosthesis. Participants were not able to adjust the panels in this first mode. The second mode allowed participants to manually make panel adjustments, incrementally enlarging or tightening the panels radially. Lastly, the third mode implemented the automated controller developed in the previous aims. Participants were still able to make manual adjustments to the panel positions but during walks adjustments would also occur automatically. Each mode was tested for a minimum of 1 week.

Device: Adjustable socket

Interventions

Adjustable socket DEVICE

The adjustable prosthetic socket will be used to test the influence of socket size adjustments during sitting, standing, and walking activities to determine if these strategies can be used to improve socket fit and reduce fluctuations in limb volume.

Aim 10 - Adjustable Socket Out of Lab Testing; Aim 2 - Adjustable Socket - Researcher Controls; Aim 3 - Adjustable Socket - Participant Controls; Aim 4 - Adjustable Socket - Automatic Controls; Aim 6A - Release/Recovery - Researcher Controls; Aim 6B - Release/Recovery - Participant Controls; Aim 8 - Panel Pull During Resting; Aim 9 - Panel Pull During Ambulation

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• years of age or older
• Unilateral transtibial amputee
• At least 6 months post-amputation
• Wear prosthesis at least 3 hours per day
• Use an elastomeric (i.e. gel) liner
• K3 or higher Medicare Functional Classification Level
• Able to walk continuously with prosthesis for at least 5 minutes at a time, sit, stand, and step up a height of 5.0 cm.
• Residual limb of 9.0 cm or longer
• Experience problems with volume fluctuations that affect their prosthetic socket fit

You may not qualify if:

• Participants experiencing skin breakdown on enrollment will be excluded, but can enter after having been free of clinically visually-apparent skin breakdown for two weeks.

Sponsors & Collaborators

• University of Washington: lead

Study Sites (1)

University of Washington Bioengineering

Seattle, Washington, 98195, United States

Location

MeSH Terms

Conditions

Wounds and Injuries

Results Point of Contact

• Title: Daniel Ballesteros
• Organization: University of Washington

danieb25@uw.edu

206-221-5873

Study Officials

• Joan E Sanders, PhD

  University of Washington

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: SUPPORTIVE CARE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: May 3, 2018
• First Posted: June 8, 2018
• Study Start: August 7, 2015
• Primary Completion: September 1, 2021
• Study Completion: January 1, 2022
• Last Updated: May 3, 2023
• Results First Posted: May 3, 2023

Record last verified: 2023-04

Locations

US (1)