Stump Cone

Marissa Ammer

Jonisha Pollard

Alison Saulsbery

Mentor: Bob Maguire

DeLatorre Orthotics and Prosthetics, Inc.

BioEng 1161

Dept of Bioengineering

University of Pittsburgh

April 18, 2005

Amputation Procedure

www.wheelessonline.com Sugarbaker, Bickels, Malawer; “Above-knee Amputation” www. Sarcoma.org

Background• Post-amputation dressings are applied to

stump to:• Reduce edema (fluid collection)• Prevent Thrombo (clotting) and embolic

(occlusion of blood vessels) complications• Stabilize stump shape• Protect the stump from injury

• Three types of dressings: soft, semi-rigid, rigid• Soft dressings become a hassle, rigid dressings

do not allow for wound cleaning or expansion• Our device is semi-rigid

Types of Dressings

Soft Rigid Semi Rigid

Ace bandage Cast “Crash Helmet”

Competitive Analysis

• Soft dressings, Ace Bandages• Rigid dressings, such as casts• Weight bearing devices, such as

FloTech• Semi-rigid removable dressings,

such as PSRRD, “Crash Helmet”

Design Criteria• The Stump Cone will use surgical

spacer socks that can easily accommodate shape change throughout the day

• As the residual limb becomes smaller, the device will be able to fit around it maintaining compression

• The shell will be a harder plastic to protect the limb against bumps and falls

Economic Consideration• Hopefully covered by health

insurance, but if not completely, still relatively inexpensive.

• Market Size – $360 million in North America• 3 million patients • $1200 allowable charge for insurance

(Anthem Blue Cross Blue Shield)• Product will be distributed through

hospitals and medical centers

SolidWorks Modeling

• First designs in the planning stage

Final Design

Advantages of the New Design• Shock protection

• Via Comcore – patented composite material with excellent impact strength and fatigue life

Advantages

• Fluid Drainage through drainage holes

Advantages

• Adjustable • “clam shell”• Velcro

strapping

Advantages

• Pressure Relief• Thermo plastic

material• Bottom opening

Advantages

• Antibacterial Protection• Charcoal padding- activated charcoal

absorbs bacterial toxins and odor.

Advantages

• Non-weight bearing• Less bulk

• No buttock support

• More comfortable for user

• Best of both worlds• Integrating features from soft

and rigid dressings

Advantages

Methods to Test the Stump Cone

• Run an FEA in COSMOSWorks

• Survey prosthetists on what they think of the device

Results of FEA Testing

50 lbs Normal Force

Factor of Safety = 4.2

(Design Check)

Results from Testing

• Survey Results from Prosthetists:• Comfort Level: 8• Pressure: 8• Ease of Use: 8.75• Adjustability: 7.25• Protection: 9.25

• On Scale of 1 to 10, where 10 is the best

FDA Regulations

• Class I Device

• Permanent Device (greater than 30 days of use)

• Contact with the skin

Acknowledgements

• Funding Contributions• Drs. Hal Wrigley and Linda Baker• The Bioengineering Department

• Donation of Materials from DeLatorre O&P• DeLatorre O&P of Pittsburgh Personnel

• Brian – the technician that made our prototype• Drew Buffat, CP - Director of Prosthetics• Bob Maguire, CP• Jason, Head Prosthetic Technician

• Department of Bioengineering, University of Pittsburgh