The

Stand-N-Shower

Transfemoral Shower Prosthesis

Team Footloose

Selvin Amador�Kathryn Gaynor�Connor Kennedy

Sam McQuaid�John Miller�

Problem Statement

There are no solutions that are both convenient and affordable to help transfemoral amputees retain their independence while showering.

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Purpose of Our Project:

To provide above-knee amputees with greater independence and freedom in the shower for an affordable price

Problem Background

Why the problem exists

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Transfemoral (adj.) - occurring across or involving the femur (Merriam Webster Medical Dictionary)

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(i.e. above the knee)

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Levels of Transfemoral Amputation

K-Levels Explained

K0 – No Mobility. Base level assigned to amputees who do not have the ability or potential to ambulate or transfer safely with or without assistance. A prosthesis does not enhance the quality of life or mobility of the amputee.

K1 – Very Limited Mobility. The amputee has the ability or potential to use a prosthesis for transfers or ambulation on level surfaces at a walking pace.

K2 – Limited Mobility. The amputee has the ability or potential to use a prosthesis for ambulation and the ability to adjust for low-level environmental barriers such as curbs, stairs, or uneven surfaces.

K3 - Basic to Normal Mobility. The amputee has the ability or potential to use a prosthesis for basic ambulation and the ability to adjust for most environmental barriers.

K4 – High Activity. The amputee exceeds basic mobility and applies high impact and stress to the prosthetic leg. Typical of the prosthetic demands of the child, active adult, or athlete.

In short, the higher the K level the more activity the amputee can perform

Post-Amputation Challenges

• Not only physical but also psychological and psychosocial in nature
• Anxiety, depression, feelings of inferiority
• Loss of personal dignity, independence, and freedom

Existing Solutions

Solutions that are currently available, but not ideal

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• DryPro Plastic Shower Cover
• Flimsy
• High risk of accidental exposure to water
• No access to residual limb during shower

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• Aqualine Waterproof Prosthetic System
• Expensive ($15,000+)
• No access to residual limb during shower

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• Lytra Shower Leg
• For transtibial (below knee) amputees only

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Our Design Solution

An Intro to Our Creation

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“Socket”

Upper Pylon

Lower Pylon

Foot with Limited Slip Sole

Ischial Tuberosity Support

Primary Design Functions

1. Independence
2. Accessibility
3. Stability
4. Portability
5. Adjustability

1. Independence

• Eliminates need for an assistant or shower chair
• No modifications to shower or tub necessary
• Provides greater in-shower mobility

2. Accessibility

• Innovative “socket” design provides access to the residual limb while maintaining security

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3. Stability

• Anti-slip treads on bottom surface of foot

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• No actuating knee joint

4. Portability

• Slim, compact design
• Three points of separation
• Lightweight and durable materials

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5. Adjustability

• Two points of adjustability for wide range of customization
• Accommodates most heights, weights, residual limb lengths/sizes
• Use of Boa System for fine-tuned adjustment of socket diameter

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The Boa System

An innovative lacing system that creates a precise and snug fit by using a micro-adjustable dial, strong lightweight laces, and low-friction lace guides

Concept Sketch of the Stand-N-Shower with the Boa System

Operating Specifications

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Functionality

• Designed to handle axial load of 200 lbf

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• Maximum operating temperature of 180°F

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• Current prototype allows for ≤6in. diameter residual limb

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Development and Construction

How we brought our design to life

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Build Timeline

• Original prototype made
• Crutches used to aid in design and fabrication
• Second prototype made
• Residual limb attachment made and affixed

Division of Work

• Kathryn
• Communication with professionals
• Design sketches
• Testing
• Connor
• CAD modeling
• Testing
• Selvin
• Contact with primary machinist
• Testing
• Sam
• Material selection
• John
• Testing
• IRB
• Work with Dr. Kranov

Build Process/ Assembly

“Leg Day” prototype

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• All parts made from aluminum
• Very stable
• Heavy

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“Skip Leg Day” Prototype

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• Very stable
• Lightweight
• Limited Slip rubber sole
• Height adjustable

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Build Photos

Skip Leg Day Prototype

(Lower Parts)

Skip Leg Day Prototype

(Upper Parts)

Complete Assembly

Hardware Details and Cost Analysis

What it’s made of

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Prototype Costs

Design Testing

How we tested our design prototype

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Primary Testing Methods

• In-Lab Testing
• Instron Compression Test
• Friction Sled Test

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• Human Subjects Testing
• Fit and Comfort Test
• Limb Accessibility Test

In-Lab Testing

• Instron Compression Test
• Proof loaded the system to 25% over the designed load
• Done with just the leg and then again with the “socket” attachment in place

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• Friction Sled Test
• Tested the foot using a ceramic tile (less friction than a tub/shower floor)
• Performed a dry and wet test

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Human Subjects Testing

• Required approval from the University’s Institutional Review Board (IRB)

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• Tedious
• Six revisions to consent form, testing procedures, and wording were necessary

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• Good Experience
• Completed the NIH web-based training course “Protecting Human Research Participants”

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Test Results and Analysis

Interpreting our data

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Test Results & Interpretation

~10 Newtons

~22 Newtons

Coefficient of Friction: F=Mmg

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Market Potential

Where and how our design could compete commercially

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Potential Consumers

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• Those who live in the same household as other transfemoral amputees

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• College students using communal bathrooms

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• Frequent travelers

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• Those who value their independence

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Professional Analysis

Courtesy of Dennis Haun of Metro Prosthetics

• Overall design and estimated selling price of $100 are highly favorable compared to competing devices

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• Current design is most suitable for those at K-3 level of ambulation (~25% of Metro Prosthetics’ patient population)
• Absence of a locking knee joint component means user cannot don prosthesis while sitting

Improving Marketability

• Addition of a locking knee joint component would open up consumer base to K-1 and K-2 level users

Future Work

The next steps we would take

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Our Next Steps

Integrate Boa System to final prototype

Perform fit and comfort testing with human participants

Produce final product

Adjust design as necessary

Repeat testing as needed

Boa Closure System

Moving Anterior Plate

Locking Knee Joint here

Video of Sliding Solidworks Model

Critical Self-Assessment

The lessons we learned

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Critical Self-Assessment

1. Put a consistent meeting schedule into place as soon as possible

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• Regularly consult professionals/specialists

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• Take advantage of empty personal time to get something done

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• Communicate with team members constantly

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Credits

Special thanks to everyone who helped bring our project together:

• Dennis Haun (Metro Prosthetics)
• Pedro Almazo (Dejana Truck & Equipment)
• Dr. Kranov
• Dr. Pond
• Dr. Tangrea (Sinai Hospital)
• Dr. Brown (Sinai Hospital)

Questions

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