StretchPRO
Kevin Ritchey (LTU), Norah Hammad (LTU), Brendan O’Neil (UDM), Arafat Abdulmalek (UDM), David Duron (UDM), Ashley Gwiazdon
(UDM), Austin Carlisle (UDM)
Client Information
- 46 year old male involved in motorcycle accident 23 years ago
- Partial spinal cord injury → Brown Sequard Syndrome → Spasticity
- Requires two people to separate legs
- Cane or wheelchair
Current Treatment Options
- Leg separator machines- Expensive- Heavy- Won’t fit between patient’s legs
- Leg separator pillows- Will not fit between legs- Do not keep legs straight
- Muscle relaxers- Patient has tried them without success
- Physical therapy
Market Analysis
- Costs of treatment- Leg stretch machine = $175 - $350- Pillows = $20 - $50
- Medications- $120 -$2500/year
- Spasticity affects more than an estimated 12 million people worldwide
- 80% of people with CP experience spasticity
- 400,000/500,00 in U.S.- 80% of people with MS experience
spasticity- 320,000/400,000 in U.S.
Need Statement and Strategic Focus
Need Statement: Patients who suffer from spasticity in their legs and groin need to be able to stretch and separate their legs without assistance, in a safe and effective manner.
Strategic Focus: Create a convenient and cost-efficient device that will allow our client to accomplish tasks he is currently unable to do. We are interested in solutions that will increase the patient’s mobility and/or decrease his pain level.
Design Process
- Started with 3 ideas- Independence- Able to fit between legs, ease of
manufacturing, safety- Crank design provides
independence in a novel way with more control
Design ConceptsUnstretched View Top ViewStretched View
Scissor jack Locking leg braces
Lift off hinges
Crank
- Novelty comes from use of scissor jack and detachable leg braces
- Deliverables: 3-piece device and instruction manual
Design Concept
- Patient straps on leg braces- Attaches separator via lift off hinges- Patient turns crank wheel slowly
Bevel gear assembly LIft-off hinge
Methods
- Determine separation force- Static analysis of system- Manufacture using off-the-shelf
and custom fabricated components
- Design Validation- Post-IRB client test
Budget- Funding from UDM : 1000$
- Current total (minus manufacturing): $269
-
Item Cost Reasons
Ram Scissor Jack $25 - Lightweight- 2500 lbs capacity- 18-¾” lift
Ossur Knee Immobilizers
$54/each = $108 - Fully adjustable- Provides immobilization in extended position
6061 Al Plates $60/each = $120 - Most widely used Al- 35,000 psi yield strength- Better corrosion resistance and weldability than Al 2024 and 7075
Lift-off Hinges $8/ea = $16 - 270 degree ROM- Full surface mounting- 88 lb load capacity- 304 stainless
TimelineTask Time
Client update Week of 12/26
IRB, testing, static analysis, acquire materials
Month of January
Complete first prototype Week of 2/13
Testing and modifications Remainder of February
Build 2, client testing, and modification Month of March
Final build and presentation prep Month of April
Deliver product to client First week in May
- Weekly meetings with
whole team- Weekly
meetings with advisor
Team Structure
LTU Students UDM Engineers UDM Nurses All
Biomechanics - Kevin
Device mechanics Anatomy Design ideas
Ergonomics - Norah
Manufacturing Patient monitoring
Crank design - Both
Jack/plate/leg interfaces
Brace design/selection
Impact & Bigger Picture
- We take the ability to separate our legs for granted- Patient has been unable to do so for nearly half of his life- Increase mobility
- Device can have applications beyond our client’s needs- Fitness, martial arts- Other patients with spasticity- IP
References
1. @medchrome. "Brown-Sequard Syndrome - Anatomical Basis | Epomedicine." Epomedicine. N.p., 25 July 2016. Web. 09 Dec. 2016.
2. "Brown-Séquard Syndrome." Wikipedia. Wikimedia Foundation, n.d. Web. 09 Dec. 2016.3. 3. IngeborgK. "Bend Sheet Metal." WikiHow. N.p., 09 Dec. 2016. Web. 09 Dec. 2016.4. "Lift-Off Hinge, Natural, 2 X 1-11/16 In." Battalion Lift-Off Hinge, Natural, 2 X 1-11/16 In. 3HUF8 | Zoro.com. N.p., n.d. Web. 09
Dec. 2016.5. "McMaster-Carr." McMaster-Carr. N.p., n.d. Web. 09 Dec. 2016.6. "Ossur Universal 3-Panel Knee Immobilizer." Ossur 3-Panel Immobilizer | The Brace Shop. N.p., n.d. Web. 09 Dec. 2016.7. "Ram Scissor Stabilizer Jack - 18-3/4" Travel - 2,500 Lbs - Qty 1 Etrailer Camper Jack TJSC-24." Etrailer.com. N.p., n.d. Web.
09 Dec. 2016.8. Saulino, Michael. "Economic Impact of Spasticity and Its Treatment." Spasticity: Diagnosis and Management. 2nd ed. N.p.:
Demos Medical, 2016. 479. Print.