1. Development of Depth Gage Instrument Brian Cost Justin Johnson Tyler Kibbee February 19, 2008

2. Project Description Design, build and test an improved depth gage instrument for a variety of orthopedic surgeries Achieve bi-cortical fixation using a compression stopper Ergonomic Grip Ease of use for surgeons Accuracy Proper depth and correct size screw used

3. Existing Design Inadequate measurements Unable to engage far cortex of bone Poor repeatability Discuss weaknesses in MAUDE results

4. Current Status Obtained 2 saw bone models Hand and Foot models Additional implants on order Drill Bits, drivers Plates, screws Revised switch to compress tip Set up to meet with Doctors at VUMC Dr. Dan Spengler Dr. Kurt Spindler Dr. Thomas Limbird

5. Feedback Derek Lewis, advisor Surgeons are used to ergonomics of old design—minimal changes Currently critiquing design with president of OrthoHelix Surgeons Design needs to be for one handed operation Needs to slide smoothly Switch needs to be relatively easy to flip

6. Current Depth Gage Design

7. Switch Demonstration

8. Tip Demonstration Before Compression (switch disengaged) After Compression (switch engaged)

9. Experimental Testing Material testing Stainless steel  Autoclave Medical-grade Silicon  Autoclave, heat resistance Failure testing Pull-out strength  Amount of force needed to pull silicon through hole Silicon-strength testing  Bone pressing against silicon

10. Sawbone Models

11. FDA Classification Class I – Surgical devices Sec. 888.4300 Depth gauge for clinical use. (a) Identification. A depth gauge for clinical use is a measuring device intended for various medical purposes, such as to determine the proper length of screws for fastening the ends of a fractured bone. (b) Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter, subject to the limitations in 888.9.[52 FR 33702, Sept. 4, 1987, as amended at 66 FR 38815, July 25, 2001]

12. Project Timeline SolidWorks 7.0 3D modeling Revise 3D models with advisor Create additional Model Simulation Shadow Surgeons at VUMC Product design input SLA plastic prototype Quick, cheap prototype for visual inspection 1 st SLA deadline: On order (pending design approval) Test SLA prototype Use saw bone models to conduct testing Prototype contract Prepare for FDA approval Might not be before 4/22/08

13. Summary of Maude Database Results Malfunction Improper depth measurement Depth gauge does not read accurately. When used, the depth gauge reads long. Depth gauge for cortex screws was sticking and provided an incorrect measurement Translation mechanism failure The depth gauge is not sliding smoothly Depth gauge for cortex screws was sticking and provided an incorrect measurement Tip Failure A modified depth gauge reportedly broke during surgery. A ball-tip that was 3mm in diameter had fallen off and was left in the patient. Injury - None Serious Injury/Death - None

14. Complaints/Incidences of Malfunction

15. Questions?