VEXTEC Reliability Analysis of Above-the-Knee Leg Prosthesis Group 11 Aashish Bapat, April Boldt, Jason Deaner, Grainger Greene, Dani Shuck

Project Need  VEXTEC (Sponsor Company) Fatigue failure and reliability analysis Automobile and Aerospace Industry  Market Potential in Medical Device Sector  Project Overview Re-Design the existing reliability analysis protocol to cater the needs of the medical device manufactures A) Cost B) Time C) Quality

Project Goals 1. Predict reliability of above-the-knee prosthetic leg (Finite element analysis) Material Geometrical Loading Available data on failure 2. Modify the design of Reliability analysis software for the prosthetic leg

Project Goals (contd..) 3) Market Analysis Potential Medical device manufactures  Testing cost and time reduction analysis  Meetings with the medical device industry to identify specific market needs  Aid for FDA approval

Prosthesis Hardware  Socket  Knee system  Shank  Foot-ankle system

Design System and Weaknesses  Inherent Weaknesses in Prosthetic Design: Longevity of Prosthesis  Fracture vs. hardness  Material friction vs. debonding  Cyclic loading vs. corrosion Strength of bone tissue surrounding  Method of fixation/integration into bone matrix  stress shielding  dissolved tissue  Misalignment and loosening BIOCOMPATIBILITY

Market Analysis  Approximately 50% of all medical device recalls are due to design errors that could have been prevented by adequate design controls  FDA Quality System Regulation requires risk analysis as a portion of its Design Control requirements.  November 9, 2006 – FDA announced it is strengthening its postmarket approval program for medical devices

Competitors  Relex Uses fault tree analysis, reliability predictions and block diagrams, FMEA/FMECA software modules Clients for medical device software/consulting include Abbott Laboratories, GE Medical Systems, Siemens Medical Other non medical device clients include Boeing, Northropp Grumman, Motorola  ReliaSoft Similar products to Relex, including fault tree analysis and MTBF calculations Weibull++ goes for approx. $1000 for individual customer

Work Completed Visited VEXTEC on October 19 to discuss design project goals with Dr. Curtin Submitted preliminary proposal on November 2 Talked with Dr. Collins to obtain alumni contacts in the FDA Contacted Dr. Goldfarb for future assistance in finite element analysis techniques Talked with Dr. Bers to discuss market potential and obtain permission to participate in the Technology Marketing course

Current Work  Tuesday, Nov. 28 Meeting with Dr. Bers on Market Analysis  Background Research completed by December 15 Technology  Prosthesis development since WWII  Current technologies  Prediction of future development Market  SBIRs  Need

Future Work  Development of MATLAB code by February 27  Development of MATLAB reliability analysis by March 30 Selection of most likely site of failure Finite Element Analysis – ProE  Manufacturing parameters MATLAB simulation  Poster and Design Report by April 26th

Roles Sponsors  Dr. Curtin  Dr. King Advisors  Dr. Collins  Dr. Goldfarb

Questions?