Senior design project to meet customer requirements and benchmarks - working with Zimmer, surgeons, and manufacturers to create a redesign for a mutli-angular surgical drill shaft used in minimally invasive surgeries.

1. Multi-Angular Drill Shaft
Tuesday, May 31, 2005
Chester Bennett
Joslyn Bradley
Scott Russell
Ryan Schlotterback
Mark Svendsen

2. Project Background
Purdue Mechanical Engineering program
recently rated 7th best Mechanical
Engineering program in the nation
Zimmer Holdings, Inc. the largest
orthopedic engineering company, based
out of Warsaw, IN
Tuesday, May 31, 2005 Zimmer/IUPUI 2

3. Product Description
Zimmer to redesign a
flexible drill shaft
Current shaft does not
meet customer
requirements
Surgeons use drill shaft in
MIS to drill pilot holes for
replacement hip sockets
Incisions is small, so drill
shaft flexes to reach pilot
holes
Tuesday, May 31, 2005 Zimmer/IUPUI 3

4. Surgical Use
Tuesday, May 31, 2005 Zimmer/IUPUI 4

5. Zimmer Requirements
Surgical approved material
Cleanable or Single Use (Preferred)
Wide angle of orientation - 90° minimum
Non-locking angle orientation
Durable – Higher torsional strength
Operates in forward and reverse
Zimmer connections
Instrument dimensions
Prints
Tuesday, May 31, 2005 Zimmer/IUPUI 5

6. Engineering Specifications
Non-negotiables Angle Orientation
Surgically approved 90° minimum
material
Stiffness
Cleanable – for multiple
use device Deflection - 0.150 inches
Operate in forward and Durability
reverse
3 N*m or 26.6 in*lbs
Zimmer Connections
Product Life
One time use
Cost less than $50
Tuesday, May 31, 2005 Zimmer/IUPUI 6

7. Concept Generation
Braided SS Shaft
with a Teflon Core
Polymer Shaft
Nitinol Shaft
Tuesday, May 31, 2005 Zimmer/IUPUI 7

8. Design Validation - Torque
Experimental Analysis
Torque Results
Reached 26.6 in·lbf of torque
Met the target value for torque
Exceeded current Zimmer requirement of 25 in·lbf
Tuesday, May 31, 2005 Zimmer/IUPUI 8

9. Zimmer Flexibility Testing Setup
Vertical supports
must be 1.5 inches
apart
A load of 47 lbf is
applied to the shaft
Shaft must deflect at
least 0.15 inches
Tuesday, May 31, 2005 Zimmer/IUPUI 9

10. Design Validation - Flexibility
Flexibility Results
A load of 11 lbf was
applied.
The shaft deflected
0.40 inches.
Exceeded flexibility
requirement of 0.15
inches considerably.
Tuesday, May 31, 2005 Zimmer/IUPUI 10

11. Cost Analysis
Cost of braided stainless steel shaft: ~$4
Cost of Zimmer end pieces, currently:
$50/end piece.
Recommendation: reduce cost by utilizing 304
stainless steel material
Tuesday, May 31, 2005 Zimmer/IUPUI 11

12. Cost Analysis
One time use device
Below $50
Tuesday, May 31, 2005 Zimmer/IUPUI 12

13. Final Design Specs
Length – 2.75 inches
Diameter - 0.250 inches
Assembly – Ø 0.096 SS Roll Pins
One time use
Cost - ~$37
Tuesday, May 31, 2005 Zimmer/IUPUI 13

14. Final Design Performance
All the critical design parameters were met by
the newly designed drill shaft
Significant achievements of the braided wire shaft
Flexibility requirement
Torque requirement
Forward and reverse operation
Disposable device
Tuesday, May 31, 2005 Zimmer/IUPUI 14

15. Impact of Design
Safety
Surgically approved materials
Contamination risks reduced
Environmental
No hazardous materials
Recycle components
Society
Improves surgical operations
Tuesday, May 31, 2005 Zimmer/IUPUI 15

16. Zimmer Involvement
Platform for success
Provided tools and resources
Provided industry contacts
Contacts provided customer requirements
Product meets customer requirements where
others do not
Tuesday, May 31, 2005 Zimmer/IUPUI 16

17. Purdue Involvement
Provided understanding of engineering
principles
Process of design provided clear goal:
meet customer requirements
Process of design provided steps to meet
customer requirements
Success proves our education
Tuesday, May 31, 2005 Zimmer/IUPUI 17