1. Chapter 16 Medical device reliability

2. 16.1 Facts and figures, government control and liability NFPA 1200 deaths per year due to faulty instrumentation Operator error account for well over 50% of all technical medical equipment problem. 4%-6% of hospital products were sufficient dangerous to warrant immediate correction.

3. 16.2 Medical electronic equipment classification Category A-equipment requiring high reliability because it is directly and immediately responsible for the patient’s life or which may become so in emergencies. Category B-used for routine or semi-emergency, there is time to repair. Category C-not essential to a patient’s life or welfare but serves as a convenience equipment.

4. 16.3 medical device recalls The recalls were classified into 9 problem: Faulty product design Contamination Mislabeling Defects in material selection and manufacturing Defective components Miss assembly of parts Electrical problem Radiation violations No pre-market approval and failure to comply with GMPs

5. 16.4 Medical device design quality assurance FDA preproduction or design quality assurance program is composed of 12 elements: 1.Organization 2.Specification 3.Design review 4.Reliability assessment 5.Parts/material quality control 6.Software quality control 7.Design transfer 8.Labeling 9.Certification 10.Test instrumentation 11.Manpower 12.Quality monitoring subsequent to the design phase

6. 16.4.1 Organization Preproduction quality assurance program (PQA) 16.4.2 Specification Performance characteristics, such as reliability, safety, stability and precision 16.4.3 Design Review FMECA FTA (fault tree analysis

7. 16.4.4 Reliability assessment Parts reliability, subsystem reliability and system reliability 16.4.5 Parts/material quality control Develop a preferred P/M list 16.4.6 Software quality control SQPA

8. 16.4.7 Design transfer Transfer to scale up production 16.4.8 Labeling 16.4.9 certification Overall adequacy of quality assurance plan. Resolution of any discrepancy between the standard/procedures employed to construct the design during the research and development phase and those identified for the production phase. Adequacy of specifications. Suitability of test approaches employed for evaluating compliance with the approved specifications. Adequacy of specification change control program. Resolution of any discrepancy between the approved specifications for the device and the end product device.

9. 16.4.10 test instrumentation 16.4.11 Manpower Enough qualified person to perform the design activity 16.4.12 Quality monitoring subsequent to the design phase Identifying trends or patterns associated with device failures. Performing analysis of quality related problem. Initiating appropriate corrective measures to stop recurrence of the above failures or problems. Reporting in a timely manner the problems found either in-house or in the filed use.

10. 16.5 Human error occurrence and related human factors 16.5.1 Control/Display related human factors guidelines Controls, displays and workstation are designed considering user capability. Switches and control knobs correspond to medical standard Design facets are consistent with user expectation. Control and display arrangements is well organized and uncluttered. Tactile feedback is provided by control Knob,switches, keys are arranged and designed to prevent any inadvertent activation. Color and shape coding is easy to identification. Intensity and pitch of auditory signals easy to be heard. Visual signal’s brightness is easy to be perceived. Items should consistent between display and instructional manual.

11. 16.5.2 Medical device maintainability related human factor problems 16.5.3 Human factor pointers for already being used/to be purchased medical devices Information come from 1.Complains 2.Observation 3.Installation problems 4.incidents

12. 16.6 Medical device software 16.6.1 Software testing for improving medical device safety Manual software testing Free form testing White-box testing Functional testing safety testing Approaches to manual software testing Error testing

13. Automated software testing Four purposes: 1.To stimulate the test target 2.Monitor associated response from the device 3.Record the end results or conclusions 4.Control the total process.

14. 16.6.2 Quadriplegias delivery system software reliability program core elements and software safety improvement with redundancy 16.7 Source for adverse medical device reportable events and failure investigation documentation 1.Service/repair reports 2.User/distributor records 3.Published/unpublished literature sources 4.The manufacturer’s product complaint-handling mechanism 5.In house research/testing evaluation/etc. records 6.Legal records 7.Sales representative contact. 8.Technical service customer contacts.

15. 16.8 A small instrument manufacturer’s approach to produce reliable and safe medical devices 1.Analyze existing medical problems 2.Develop a product concept to find a solution to a specific device is operating 3.Evaluate environments under which the medical device is operating. 4.Evaluate the people expected to operate the product under consideration 5.Building a prototype 6.Test the prototype under library environment. 7.Test the prototype under the field operating environment. 8.Make changes to the device design as appropriate to satisfy the actual field requirement.

16. 16.9 Aerospace and medical equipment reliability and reliability approach comparison