neckbrace design for patients with amyotrophic lateral sclerosis (als) sarah calano maneesha kumar...
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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