1. Prosthetic Ear Fixation March 9, 2007

2. Design Team Team Members Cullen Rotroff Evan Rogers Joe Hippensteel Steve Noel Ashley Phillips Advisor Prof. Willis Tompkins, PhD Client Greg Gion, MMS, CCA

3. Background Microtia - congenital deformity of the outer ear 1 in every 8,000-10,000 births Auricular (ear) prostheses can be made to mirror the contra lateral ear Prosthetic ear can be inadvertently removed http://www.medicalartprosthetics.com/auricular.htm

4. Background Attachment of auricular prosthesis: Titanium keepers are screwed into bone of the patient Magnetic post is screwed into keeper Prosthetic ear contains magnets, oriented to be placed on top of magnetic caps Usually 3 abutments are placed in a triangle, although placement is custom for each patient http://technovent.com/asp/about.asp

5. Problem Statement Our goal is to design a new attachment mechanism that: Can be discretely placed behind the prosthetic ear Does not allow accidental removal Requires little force for attachment and detachment Can be easily cleaned for hygiene purposes Is compatible with keeper

6. Push Tab Mechanism Three moving components; one male, one female, and one spring User compresses male and female parts together to move around posts

7. Push Tab Mechanism Pros Secure Ease of Use Patient does not have to touch silicon

8. Design Concerns oRelies on two abutments oHard to make discrete oWear on spring oHard to customize

9. Spring-Clip Mechanism Squeeze edges of ear Slide clips into slots o Ergonomic o Keeper-compatible post o Discrete o Hygienic o Simple Design Compressive Spring Ear Prosthesis Clip-in Process Mastoid Bone Overview

10. Design Concerns o Possible functional inadequacy due to size o Difficult to machine o Requires new post element o Fragile clipping component

11. Clipping Post Mechanism Keeper compatible female post Central plunger unlocks clip for easy removal Breakaway force protects Prosthesis Varied entry and exit slopes control force requirements

12. Locking disk pushes down on 4 clips Entry angle absorbs normal force, pushing clips outwards Clips recoil around disk to lock Shallow exit slope requires large removal force How it works: Locking

13. How it works: Removal o Depressed plunger opens clips o Disk slides out of clip with minimal force o Breakaway force protects prosthesis

14. Design Concerns o Manipulating plunger through prosthesis oPlunger locking mechanism o Requires new post element o Small components may be fragile

15. Future Work Conduct tests to determine forces Determine attachment to ear (implantation?) Finalize design and present to client Build model

16. References