ADAPTABLE RETRACTOR FOR

TOTAL HIP REPLACEMENT

SURGERYTrey DeLong

Lacey GorochowBrian Rappa

Adam VandergriffSandra Wadeer

Advisor: Dave MartinezVP of Sales at Zimmer, Inc.

Problem Statement Current tissue retractors are narrow, multiple

retractors are required especially in obese patientsNY times reports 34% adults are obese+Surgical Techs($20.00/hr*2-4hr/surgery*200k

surgeries/year)Time of surgery increases as well

Previous team designed an adjustable retractor Complex and impractical for industrial productionPrototype could not be used in surgery

Mechanism & Consequences Mechanism causing the problem

Physical properties of adipose tissue allow it to wrap around narrow retractors

  Consequences of unresolved

problemPoor surgical field of visionIncrease cost for additional materials and personnel

Surgery Experience

Fat tissue getting in the way

4-5 in (6 in in bigger patient)

3 in wide

Dr. Christie’s Perspective Functions of retractor:

Pull on incisionKeep tissue from falling into surgical window

Disposability Not “green”

Ideal Device:Robust Simple Movable window

Design Requirements & Objectives Keep back adipose tissue Fit multiple patient sizes and provide a clear view

of the surgical site Must be cost efficient

Simple manufacturingcheap material

Ready for use in surgeryEasily attachedEasily sterilized

Strong enough to hold back fat tissue

Preliminary Design Similar to cheek

retractor Plastic material Disposable Hands-free Does not allow for

mobile window No relaxation on one

side (non-movable window)

Preliminary Design #1

4 in

1 in sliding room

Guide Rails

Flap(similar to cheek retractor)

Preliminary Design #2

3 guide rails inside this part

Preliminary Design #3

Retractor

Attaching Part

Guides

Rails

Preliminary Design #3

Goals Reduce total hip replacement surgery

costLess personnel in the operating roomLess retractors needed for surgery

Increase vision and work room for the surgeonIncrease efficiency of the surgeryReduce surgery time

Performance Metrics Retractor system work on 95% of patients

Different size attachments for non-disposable and disposable design

CostsKeep production costs minimal

○ Mass production○ Readily machined

Predicted to be ~$300 for retractor and attachments (non-disposable)

Disposable: $1-$10 per device

System and Environment Role in surgery

Increase view of region and allows access Why its beneficial to the surgeon

Reduce people near patientReduce number of retractorsMake surgery easier

Testing Methods Verification

Ensuring all parts of the device function together properlyDetect errors at all stages of development

ValidationDetermine whether device is easily sterilized

Hardware TestingUse of mechanical equipment to test strength of device

Stress TestingPro/E Mechanical Analysis

Safety Testing Take into surgery and access ability to use device

Next Steps…

Visit Surgery Feb. 2

Design Sketches

3 Design Options

Final Design

Prototype Completed

Complete Testing/Surgery

Use

Presentation

6/21 8/10 9/29 11/18 1/7 2/26 4/17 6/6

Start Date

Completed

Remaining

References http://www.bls.gov/bls/blswage.htm http

://www.innomed.net/hip_rets_mis.htm#Anchor-APC-49575

http://www.nytimes.com/2010/01/14/health/14obese.html

http://www.orthosupersite.com/view.aspx?rid=1889

http://www.zimmer.com/z/ctl/op/global/action/1/id/8140/template/PC/navid/10427