Design Rationale and Design Verification. BN3101 Bioengineering Design Casey K. Chan MD

Transcription

1 Design Rationale and Design Verification BN3101 Bioengineering Design Casey K. Chan MD

2 What this lecture is about Some design issues that you may encounter in your project Recap of some important dates Product development process Conduct Design verification for your project

3 Design Issues Anatomical Variations Limited Dimension Reduce Complexity

4 Anatomical Variation Size variation Shape variation

5 Size and Shape AP ML

6 AP Dimension Anatomical Variation ML Dimension

7 AP Dimension Anatomical Variation ML Dimension

8 AP Dimension Anatomical Variation ML Dimension

9 AP Dimension Anatomical Variation ML Dimension

10 AP Dimension Racial Differences ML Dimension

11 AP Dimension Anatomical Variation Small Medium Large ML Dimension

12 Narrow Standard Wide Size and Shape AP ML Small Standard Large

13 AP Dimension Anatomical Variation Small Medium Large ML Dimension

14 Shape Anatomical Variation Small Medium Large Wide Wide Wide Standard Standard Standard Narrow Narrow Narrow Size

15 Shape Anatomical Variation Small Medium Large Wide Wide Wide Standard Standard Standard Narrow Narrow Narrow Size

16 Shape Anatomical Variation Size

17 IMPORTANT DATES Mid-term Review 35 days Quiz 49 days Design Qualification 2 months Final Presentation in 2 months

18 GROUND RULES To ensure a good time to be had by all Timelines and schedules are tight Grading Project - Team Effort (55%) Project - Individual Effort (45%) Permission required for Late submission Project + Assignments Must be original work Acknowledge information source Team Project require individual submissions

19 Project Grading Project (Team Effort) 55% Presentation 15% Design 15% Documentation 15% Functional Prototype 10% Project (Individual) 45% Individual Report 15% Peer Review 10% Mentor assessment 10% Quiz 10% (1 hour, 14 th Oct 2013, 11-12pm, EA Engineering Auditorium)

20 Purpose of Documentation Record of proposal Continuity of project in case a team member leaves Reference for further detail analysis Audit Trail Review by consultants Part of Design History File

21 Comments of some of the current documentations lab book Read the instructions of the front pages Do not write on the back of the page Not for recording Do not paste one page on top of another page Sign across pasted pages Read and understood is an important phrases

22 Design History File Documented evidence of conformance to quality system requirements (FDA / ISO) Contents Project Planning Project Team Design Inputs Design Outputs Design Verification Design Validation Clinical Evaluation Regulatory Approvals

23 Product Development Process Design Input Design Review Design Output Planning Concept Development System Level Design Detail Design Design Verification Prototype Bench Testing Acceptance Criteria Clinical Trials Design for Manufacturing Production Ramp-up End Point for BN3101

24 4 Main Activities of this Project Develop Design Input Design solution for your medical device Achieve 1 st Phase of Design Output Design Rationale and Verification (Acceptance Criteria) Documentation

25 Product Development Process

26 Design Qualification User Needs Design Input Design Process Qualification Design Output Verification

27 FDA Design Guidance

28 Design Verification BN3101 Design Input User Specifications User Need => Target Values Design Process Engineering and CAD Drawings, Lab Book Concept Generation, Brain storming, Complementary Configuration Design Output Design Rationale and Design Verification Distil concept => Document concept selection and how design achieve concept to meet Intended Use Acceptance Criteria and Tests Protocols Prototyping Testing and Documentation of Test Results Design Review and its Documentation Design Change and its Documentation

29 Validation vs Verification Verification Specified requirements (acceptance criteria ) have been fulfilled Validation Requirements for a specific intended use can be consistently fulfilled. Process Validation product meeting specs Design Validation specs conform with user needs and intended use Example of axial compression strength of disc prosthesis Specified requirement - compressive strength=65kg verified by compression testing Some patients with this implant have failure of disc prosthesis after 2 years Design Verified but NOT Validated

30 Validation vs Verification Validation can only follow successful verification

31 Design Output Requirement per FDA Design Control Guidance Documentation to show that Design Output conforms to Design Input Requirement Establish Design Output Acceptance Criteria Documented, reviewed and approved before release Approval require proof of signature and date

32 Acceptance Criteria Conformance to Design Input Identify characteristics of the design that are crucial to the safety and proper functioning of the device State Evaluation Criteria Test Procedure End Point Basis for Design Review

33 Discuss with your supervisor on the design verification There are five projects Different design verification and demo protocols Discuss with your supervisors

34 Design Cycle FDM Prototype Non-functioning Acceptance Criteria End Point for BN3101

35 Design Rationale and Design Verification Template 1. User Needs/Intended Use 2. Responsibility 3. Product Description and Scope 4. Design Verification This document captures the essence of Design Output in the FDA Design Control Guidance document

36 Design Rational and Design Verification Template 1. User Needs/Intended Use 2. Responsibility 3. Product Description and Scope General description of how implant work and why you choose this design to meet your intended use. 1. Implant (type) 2. Material 3. Technical Advantages 4. Preliminary Specifications and Instrumentation 4. Design Verification Design Rationale May give overall dimensions. May refer to Engineering Drawing

37 Design Rational and Design Verification Template 1. User Needs/Intended Use 2. Responsibility 3. Product Description and Scope 4. Design Verification (Acceptance Criteria) Mechanical Tests Static vs Cyclic Functional Tests Biocompatibility Tests Cadaveric Implantation

38 Suggestions for developing acceptance criteria Any approach which establishes conformance with a design input requirement ASTM Weakest link tests Failure mode analysis Guidance Documents FDA Adverse Reports (MAUDE) Manufacturer and User Facility Device Experience Database Peer Review Literature

39 Guidance Document

40 Adverse Event or Product Problem Description Report Date: 11/25/2003 MDR Text Key: Patient Sequence Number: 1 During an open bankart repair and clinical evaluation of the 2. 9 mm bioraptor, three suture anchors broke. The surgeon successfully inserted two suture anchors without issue. Surgeon went to insert a third anchor, upon impacting the anchor it broke. This was attributed to the angle it was being inserted. A fourth anchor was placed without issue. The surgeon attempted to implant two additional anchors which bent and broke. All three broken anchors were removed. A delay of about one minute took place. Surgeon used a 3. 5 mm twinfix anchor to complete the repair. No pt injury or complications were reported.

41 How much is enough? Acceptance value high Disadvantage Verification may be hard to achieve There may not exist a feasible design Advantage Higher acceptance by surgeon Good marketing advantage Design is robust if verified Acceptance value low Disadvantage May not satisfy intended use Advantage Easily Verified

42 How many tests is enough? Large number of tests Disadvantage Verification hard to achieve or There may not exist a feasible design Advantage Design is robust if verified Small number of tests Disadvantage May not detect design flaw Advantage Easily Verified

43 End Point Achievable Acceptance Criteria Number of Tests

44 Mid-term review (Mon 29 th Sept) 20 mins presentation + 5 min feedback Literature Review Industry Bench Marking Patent Review Adverse Event Review Design Show Prototype Design Changes Please bring your lab book for review. Each team to hand in a Project Plan Schedule.

45 Assessment Be reminded to take your online assessment which will be open from Thursday to Sunday This assessment is ungraded but some of the questions may appear in the mid term quiz, which is graded