Design Review P09006 – Upper Extremity Exerciser Wesley Adam (ISE), Matthew Oelkers (ME), Dwight Cooke (ME), Omar Ghani (ME), Andrew Krivonak(ME), Jamie Rothfuss (ISE)

Design Review Agenda Start Time Topic Of Review Required Attendees 10:00 Team and Project Introduction All 10:15 Assembled Design Presentation 10:20 Spring Attachment to Arm System 10:25 Spring Attachment to Body System 10:30 Design Feasibility 10:45 Design Feedback (Open Forum) 11:30 Dismissal

General Project Information Project Name: Upper Extremity Exerciser Project Number: P09006 Project Family: Assistive Devices Track: Assistive Devices and Bioengineering Faculty Guide(s): Dr. Matthew Marshall (ISE) Dr. Elizabeth DeBartolo (ME) Primary Customer: J.J. Mowder-Tinney Director of Clinical Education Nazareth College Department of Physical Therapy Budget: $1,500 - $2,000 Primary Market Opportunities: Secondary Market Opportunities: Stroke Victims Other Physical Therapy Providers

Project Background Mission Statement: “The purpose of this project is to redesign or create a new upper extremity exerciser, to be used in the rehabilitation of stroke victims, who have lost basic mobile function in their upper body.”

Needs Hierarchy Need 1: Safety: Need 1.1: Must maintain safe range of motion Need 1.2: Must be able to be cleaned/sterilized Need 1.3: Any and all forces exerted by device must safe to patient Need 1.4: Must be safe to physical therapist Need 2: Adjustability: Need 2.1: Must have the ability to fit patients of various height and weight Need 2.2: Must be able to be used on either side of the body Need 2.3: Must be able to be used while sitting or standing Need 2.4: Must be able to increase or decrease the resistive and assistive capability of the device Need 3: Economic: Need 3.1: Must remain within the allowed budget of $1500-$2000 Need 3.2: Must be easy to reproduce Need 4: Ease of Use: Need 4.1: Patients must be able to use device without assistance Need 4.2: Must be portable, therefore of minimal size and weight Need 5: Rehabilitative: Need 5.1: Must allow arm to rest at a patients side, 90 degree angle between upper and lower arm Need 5.2: Must provide assistance as a patient extends and then raises their arm Need 5.3: Must provide resistance as a patient lowers their arm to the rest position Need 5.4: Must allow the arm to be raised above the shoulder, to an angle of at least 90 degrees, but no higher than 120 degrees. Need 5.5: Must assist elbow extend to roughly 170 degrees between the upper and lower arm Need 5.6: Must limit motion to only that along the sagital plane Need 5.7: Device does not allow the patient's arm to extend beyond the resting position at the side of the patient's body

Project Specifications

Recap of Points Addressed From PDR Spring capabilities Inverse ratio of desired torque output Will spring shift with patient motion Will spring have adjustable forces Traverse of rotation axis with spring arm displacement Spring to arm attachment system Concern about friction from displacement of spring arm along the human arm Concern about discomfort at point of contact Spring to body attachment system Concern about devices ability to withstand forces applied by patient

Assembled Design Side View Front View

Spring to Arm Attachment System

Spring to Body Attachment System

Bill of Materials Long Medium Short or No Component Number Component Name Quantity Price Supplier Part Number 1 25lb. Mechanical Scale $9.99 Gander Mountain (585) 424-4100 22677070308 2 1/2" Galvanized Hex Bolt $1.88 Lowe's (585) 424-1340 67312 3 1/2" Galvanized Hex Nut $0.34 67342 4 1/2" Galvanized Round Washer 8 $0.28 Lowe's (585) 424-1340 63449 5 8/3 GRN PHILLIPSII EXT $8.67 Lowe's (585) 424-1340 52429 6 1lb. Box Common Bright Nail $3.37 69124 7 1/4" - 5/8" Clamp $0.97 62508 1/2" Split Ring Hanger $1.37 Lowe's (585) 424-1340 82324 9 1/2" SCH40 Cap $0.26 23937 10 12 x 1-3/16" Screw Eye $5.91 54692 11 1-7/16"-7/16 x 2 TZ ANGL C 12934 12 1/2" Pipe Straps $1.97 22144 13 $1.57 82172 14 1/2" x 5' SCH40 PVC Pipe 23967 15 1 x 12 x 2 Maple Board $14.94 44993 16 2 x 4 $2.29 6003 17 Round Stock Torsion Spring $44.25 W.B. Jones Spring Company (859) 581-7600 N/A 18 Linear Ball Bearing $45.20 McMaster-Carr (630) 600-3600 1052K11 19 Waist Belt 3.5" $9.39 MedPolitan (800) 670-7430 MP-ZRB147REG/XLG 20 Aluminum Bar Stock $15.39 86895K521 21 Aluminum Round Tube $39.92 1968T792 22 Aluminum 12" Rod $8.26 9061K131 23 Steel Sheet $26.74 1388K39 24 36" Aluminum Rod $27.17 9061K163 25 Hardware $30.00 26 Advanced Dynamic ROM $1,295 EMPI clinicaconsultants@EMPI.com Bill of Materials Lead Time Scale: Long   Medium Short or No

Advance® Dynamic ROM Fish scale attached perpendicular to end of forearm strut Foutput measured at 30° increments of θ, for settings 1,5,10 Fscale θ Foutput

Advance® Dynamic ROM Foutput(θ) created

Flagpole Prototype Process performed similar to Advance® Dynamic ROM Foutput Process performed similar to Advance® Dynamic ROM Foutput measured at 30° increments of θ θ Fscale

Flagpole Prototype Foutput(θ) created

Moment Arm Resolved Force Location = Larm-4” 90° 4” Figure A 60° 5.625” Figure B Resolved Force Location = Larm-4” Resolved Force Location = Larm-5.625” 30° 6.5” Figure C Resolved Force Location = Larm-6.5”

Torque Analysis Purpose: to find out if the EMPI spring is sufficient to provide assistance/resistance to the patient Calculated the normal component of arm weight Converted the Force to Torque F θ W θ (degrees) Force (male) Force (female) Torque Male Torque Female 0.00 10 3.54 0.89 6.3 1.6 20 6.98 1.74 12.6 3.2 30 10.20 2.55 19.1 4.8 40 13.11 3.28 25.8 6.4 50 15.63 3.91 32.9 8.2 60 17.67 4.42 40.3 10.1 70 19.17 4.79 48 12 80 20.09 5.02 55.5 13.9 90 20.40 5.10 62.4 15.6 100 68.3 17.1 110 72.4 18.1 120 74.1 18.5

Upper Arm Shaft Material strength due to bending A Conservative Approach From Matweb.com σyield = 50 ksi F = 21 lb 12 in FOS = 2.4

Upper Arm Shaft Connection τyield = 41 ksi M = 252 lb-in yields a shear force of 21.3 lb at each of the holes Fshear = 21.3 lb Farm = 21 lb M = 252 lb-in Fshear = 21.3 lb FOSshear = 94.6 σ = 1.012 ksi

Shoulder Lockout Slot From Matweb.com, σyield = 53.7 ksi At 120°, the moment is the applied torque by the spring, with no arm weight. T = 41 lb-in 0.25 in 0.125 in 0.125 in 0.125 in FOS = 6.3

95th Percentile Male Vertical Adjustment Sleeve Analysis 1.8” 0.509” 0.500” 0.0045” .O Overlap Due to the small difference in diameter of the tube and the stock lubrication will likely be necessary. However, for rotation about the center of overlapped area vertical displacement is limited to 0.0045 in. This corresponds to an angle of 0.28º about point O.

Stress and Factor of Safety Approximations for VAS Stress in tubing The inserted moment arm acts like a lever transferring force to the side wall of the tubing. The maximum moment of a male was calculated to be 74.1 in·lbs. If this is applied at point O the resulting force on the outer edge of the tubing would be = 82.3 lbs distributed on both sides of the tubing ≈ 41.15 lbs on each side. We can approximate the contact area of the tube to be 5% of the total cross-sectional area of 0.1033 in2. . An approximation of the stress can then be calculated to be psi. Assuming a yield strength of 45 ksi we get a factor of safety of n=5.6. This can be further verified with a finite element model. 1.8” 0.509” 0.500” 0.0045” .O Bending Stress in moment arm Bending stress can be approximated as the stress of a cylindrical beam of a 10 inch length with a diameter of 0.5 in. in this case M=74.1 in·lb, c=0.25 and 0.00307 therefore psi.

Project Risks adjustability & interchangeability patients ability to “cheat” device durability shifting spring or belts weight difficulty fabricating or welding parts budget force output

Questions / Comments