Snap Into Motion

Snap into motion is a senior capstone design team that is dedicated in designing a system to enable independent liner donning for transtibial amputees. Our problem statement is to design a donning system that will aid lower limb amputees don their prosthetic liner. The system will ensure that the liner sits flush against the limb,properly aligns the pin into the prosthetic, and enables those with low hand dexterity, vision, or flexibility to don their liner independently.

Background
There are approximately 34,000 transtibial amputations performed each year in the United States. The causes of these amputations range from infection to tumors with the most prevalent causes being diabetes and severe traumatic injury. Patients with transtibial amputations that wish to use a prosthetic leg must wear a prosthetic liner that protects their skin from the rough prosthetic leg materials and helps suspend their leg in the prosthetic. Prosthetic liners can be difficult to don, especially for patients with limitations in flexibility, hand dexterity, or vision. Our goal is to create a donning system that will be:
 * Comfortable
 * Easy to use
 * Work with commercial liners/prosthetic components
 * Accommodate the majority of patients
 * Reduce strain for the patient
 * Require little to no hand strength or dexterity
 * Aid inflexible individuals
 * Properly align the pin
 * Allow independent donning

Team Members
Jordan Simonson is majoring in Biological & Agricultural Engineering: Biological Systems Option. She is responsible for team organization and the wiki page.

Matthew Guthrie is majoring in Mechanical Engineering. He is responsible for the team's budget.

Jennifer Rainey is majoring in Biological & Agricultural Engineering: Biological System Option. She is responsible for all team documentation.

Samantha Sutherland is majoring in Biological & Agricultural Engineering: Biological Systems Option. She is the project manager.

Allyson Labrum is majoring in Mechanical Engineering. She is responsible for client communication.

Design Goals

 * 1) Allow for patients to don the liner themselves easily
 * 2) The pin must be aligned each time the liner is donned
 * 3) Must accomadate all liner sizes and brand variations
 * 4) Must be easy to use for patients with low hand dexterity and limited flexibility

Dimensional Analysis of Transtibial Roll-On Style Prosthetic Liners

 * Distal diameter ranges from 2.5" to 12.0"
 * Proximal diameter ranges from 3.1" to 12.0"
 * Target lenght of liners ranges from 12.0" to 16.0"
 * Pin lengths have a standard diameter of 10 mm, standard pitch of 1.5 metric, and varying lengths from 1" to 2.25"

Garter Design Alternatives
A garter is what we have named the device that will be mounted on the end of the device's arms and will be the part of the device that comes in direct contact with the patient's liner. It is named a garter because it needs to expand and accommodate different sizes of the leg.

Design Decision Matrix
We compared the drive design concepts in a design matrix that was scaled from 1-5. Based on the matrix, we decided to follow through with the glider track system with the donning hand. Below is the link to the design matrix:
 * Design Matrix

Document Archive

 * Project Schedule
 * Meeting Minutes
 * Design Review Presentation
 * Design Matrix
 * Liner Donning Force Test Results

References: