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

2. 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

3. 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

4. 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.”

5. 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

6. Project Specifications

7. 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

8. Assembled Design
Side View
Front View

9. Spring to Arm Attachment System

10. Spring to Body Attachment System

11. 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) 2
1/2" Galvanized Hex Bolt
$1.88
Lowe's (585)
67312 3
1/2" Galvanized Hex Nut
$0.34
67342 4
1/2" Galvanized Round Washer 8
$0.28
Lowe's (585)
63449 5
8/3 GRN PHILLIPSII EXT
$8.67
Lowe's (585)
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)
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)
N/A 18
Linear Ball Bearing
$45.20
McMaster-Carr (630)
1052K11 19
Waist Belt 3.5"
$9.39
MedPolitan (800)
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
Bill of Materials
Lead Time Scale:
Long
Medium
Short or No

12. 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

14. Advance® Dynamic ROM
Foutput(θ) created

15. 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

17. Flagpole Prototype
Foutput(θ) created

18. 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”

20. 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

22. 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

23. 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 = ksi

24. 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

25. 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 in. This corresponds to an angle of 0.28º about point O.

26. 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 ≈ lbs on each side. We can approximate the contact area of the tube to be 5% of the total cross-sectional area of 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 therefore psi.

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

28. Questions / Comments