Auto Control of Volume Management for Limb Loss

University of Washington104 enrolled

Overview

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.

People with lower limb amputations often experience daily changes in the size (volume) of their residual limb. These daily changes can cause a prosthesis to fit poorly. They can also cause limb health problems including skin breakdown and injury to deeper tissues. Prosthetic socket systems that accommodate limb volume changes can help address these issues, but they require users to make adjustments throughout the day. The objective of this research is to develop and test an automatically-adjusting prosthetic socket system for prosthesis users. The system integrates with a range of adjustable socket technologies, including those that are commercially available. The system allows small size adjustments for both tightening and loosening the socket. In early aims of the study, the prosthesis will be adjusted manually, but can be controlled remotely, eliminating the need to remove the prosthesis or bend down to make adjustments. The system will later be enhanced to automatically change the fit of an adjustable socket at the appropriate times, without distracting the user. We hypothesize that this system will help to maintain consistent limb fluid volume while the prosthesis user is wearing the socket and that socket fit will be improved. The system functions by continuously collecting measurements from sensors within the socket and uses small motors to control adjustable panels in the socket wall.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

SUPPORTIVE_CARE

Masking

NONE

Enrollment

104

Conditions

Lower Limb Amputation Below Knee (Injury)

Interventions

Adjustable socketDEVICE

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.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * 18 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 Exclusion Criteria: * 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.

Locations (1)

University of Washington Bioengineering

Seattle, Washington, United States

Outcomes

Primary Outcomes

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.

Time frame: 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.

Time frame: 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

Time frame: 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).

Data from ClinicalTrials.gov

This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.

Auto Control of Volume Management for Limb Loss

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes