Neckbrace Design for Patients with Amyotrophic Lateral Sclerosis (ALS)

Sarah Calano

Maneesha Kumar

Amy McNeal

Brooke Odle

April 18, 2006

University of PittsburghSenior Design – BioE 1160-1161

Overview

• Individuals with neuromuscular degenerative diseases (e.g. amyotrophic lateral sclerosis, ALS) often suffer from neck muscle weakness

• While these patients require vertical head support, they remain able to rotate their head

• Current neck braces are designed to immobilize the head and do not allow lateral mobility

Project Objectives

Our goal is to design a neck brace device that is able to:• Provide adequate support

for the weight of the head• Allow lateral rotation of the

head

Customers:• Orthotics companies

(reimbursed by insurance companies)

• Physicians (recommendations)

Quality systems considerations

• Hazard analysis:• Non collapsible material• Open design• Non abrasive, non allergenic materials

• Human factors:• Girth adjustability to allow proper fitting• Range of motion appropriate for daily activities• Washable or replaceable pieces• Durable, only padding to be replaced every 6 mo.

Regulatory considerations

• FDA Class I device (“cervical orthotic”)• Other similar devices exist within this

classification• Specifically those with open wire frame designs

(Headmaster)

• Patents• There are no other neck braces that have been

customized for ALS or designed with lateral mobility that have been patented to date

Constraints

Overall, our device design, material composition, and testing was limited by:• Cost ($500 budget)

• Material choices• Prototyping method

• Personnel (Learning curve)• Time

• Manufacturer: Hanger Orthotics

• Regulations (Limited clinical testing)

Design Iteration 1

• Lateral mobility provided through pivot joints at base of neck

• Issues: Design not feasible since pivot joints did not provide adequate support

Design Iteration 2

• Motion tracking data indicated constant arc, so pivot joint was designed for lateral rotation

• Issues: Needed larger radius (3.25 inches) than possible under the chin, not a feasible design

Design Iteration 3

• Moved lateral motion to chin piece along track

• Issues: Height adjustability feature not functional

Design Iteration 4

• Lateral translation of chin piece along track• Height adjustability through varying chin piece sizes• Issues: Painful pressure applied to sternum, Velcro

straps pull upward at an angle (destabilizing)

Design Iteration 5: FINAL

• Front support bars moved back and positioned vertically

• Additional padding along sternum

Design Iteration 5: FINAL

• Posterior neck support lined with plastic• Chin piece lined with open cell foam (memory foam)

Materials

• Actual materials:• Wire frame: Stainless steel • Track: WaterShed 11120 Resin• Padding: open cell foam, closed cell foam,

surgical tubing

• Ideal materials:• Wire frame: Aluminum wire or HD-polyethylene• Track: Any low coefficient of friction material that

can be cast• Padding: No changes

Engineering Tools

• SolidWorks 3D Design software

• VICON Motion tracking system

• Stereolithography (SLA) rapid prototyping

Features & Benefits

• Non collapsible Material Lowers chances of suffocation

• Open design Overheating less likely to occur No interference or pressure exertion to inhibit swallowing

• Adjustability Proper positioning removes interference with swallowing Alleviates soreness resulting from improper positioning

• Non-abrasive, breathable, hypoallergenic material Skin breakdown less likely to occur Overheating less likely

Competitive Analysis

Competitors:1. Philadelphia

C-breeze Collar

2. Headmaster Cervical Collar

3. Executive Collar

4. Aspen Cervical Collar

1 2

3 4

Competitive Analysis II

Our Strengths: • Lateral head rotation

possible through track device

• Discrete and open design

• Fully supports the weight of the head

• Adjustable to ensure proper positioning

• Durable (only soft goods need to be replaced)

• Easily replaceable parts

Our Weaknesses:• Not inherently height

adjustable

• Depending on wearer ability, may require assistance in securing

Design Evaluation Methods

• Doctors recommend these devices to patients• Prototypes were evaluated through surveys

and personal interviews of ALS clinicians• After trying the neck brace on, physicians and

nurses ranked the device on:• Functionality• Comfort • Appearance • Overall design

Design Evaluation Results

• According to our survey results, our brace was well received by both patients and clinicians:

Clinicians

(n=2)

Clinicians

(n=3)

Patient

(n=1)19/20 19.7/20 20/20

17/20 19.7/20 20/20

9.5/10 9.5/10 7/10

10/10 10/10 10/10

Functionality

Comfort

Appearance

Overall design

Design 4 Design 5

Project Summary

• Goal summary

• Design – developed a functional device according to specifications through 5 iterations

• Testing – patient and clinician interviews, clinician surveys completed

• Group responsibilities

Sarah Maneesha Amy BrookeClinical Manufacturing Design Documentation

ALS clinic meetings

Problem analysis & design development

Clinical & patient interviews and surveys

Contact with Hanger Orthotics

Materials research

Market research

SolidWorks modeling and design

Contact with Swanson Center for prototyping

Journal article

Patent searches

Initial business plan for design competition

Project Schedule

• Design 1: December 17

• Design 2: February 17

• Design 3: February 24

• Design 4: March 3

• Design 5: March 27

DECEMBER JANUARY FEBRUARY MARCH APRIL

Design 1 Design 2 Design 3 Design 4 Design 5

Clinic (2) Clinic (3) Clinic (4) Clinic (5)

Patient (3) Patient (5)

Journal article/DHF Business plan Design competition DHF Rev Journal article

Acknowledgements

Mentors:• Dr. Sandeep Rana (AGH)• Dr. Barbara Swan (AGH)• Linda Talmon, LPN (ALS Association)• Robert Mawhinney (Hanger Orthotics and Prosthetics)• J. Andrew Holmes (Swanson Center)• Human Movement & Balance Laboratory (VICON system)• Beverly Welte, Pittsburgh Life Sciences Greenhouse• Mark Gartner

Funding: • The generous gift of Dr. Hal Wrigley & Dr. Linda Baker• Department of Bioengineering

Thank You!

Questions?