Transcript Testing Medical Devices - IEEE Twin Cities Section

Testing Medical Devices
A Brief Overview
© 2005 Max Cortner. Copying and distribution of this document is permitted
in any medium, provided this notice is preserved.
Food and Drug Administration
Authority in the US
Criminal penalties for promoting
unapproved drugs or devices
 CDRH reviews and approves

Similar but more stringent than EU ISO
approach
Quality System “21 CFR Part 820”
Must Prove Safety and Efficacy
2
Design Controls for Class II
Devices
Planning,Input, Output, Review
Design Verification
Design Validation
Design Transfer (to manufacturing)
Design Change Procedure
Design History File – documents to
show design complies
3
Design Verification
Design Output Meets Design Input
Requirements
Identification of design (configuration
mgmt)
 Methods
 Date
 Individual performing tests

4
Typical Design Verification
Operating Range
Battery voltages
 Telemetry (range, speed, error rate)
 Temperature range

Internal Specs
Bus characteristics
 Memory operation (speed, errors)
 Sense amp operation (gain, BW, noise)

5
Design Validation
Design Conforms to User Needs and
Intended Use
Performed under defined operating
conditions (initial production lots)
 Actual or simulated use conditions
 Software validation
 Risk analysis
 Records similar to verification

6
Typical Design Validation
External Interface Specs
Indicator or display operation
 Blood pressure sensitivity, linearity,
accuracy

Simulated Use
Scenarios from users manual w/options
 Random inputs or error response
scenarios

7
Proving Safety
Clinical Trial (p People for d Days)
Compare to Existing Approved Devices
Engineering Analysis
Identify Potential Risks
 Hazards and mitigation
 FMEA
 Biocompatibility analysis of materials

8
Proving Efficacy
Intended Use
Describe diagnostic or therapeutic value
 Identify “Standard of Care” for comparison


Blood pressure cuff
“Claims” Parameters – labeling
Functions
 Useful life
 Accuracy

9
Device History Record
Requirements
Peer
Review
Design
Details
Version Control and History on ALL
Design
Verif.
Design
Valid.
V&V
Report
Peer
Review
10
Test Plans
Detail repeatable by an independent
individual of similar skill (Electrical Engr)
Set-up including equipment required
Measurement or observation to be
made (beware of observations)
Criteria for pass clearly defined
11
Test Reports
Original data must be maintained!
Signed
 Dated
 Indelible ink, no obliteration of changes

Record instrument models, s/n, and
calibration dates
Document setup (schematic)
12
Software Test
Requirements, Plan, Report (all peer
reviewed in that order)
Methods of test tailored to fit complexity
code reviews
 unit testing
 software test bench exercises
 integration testing with scenarios

Independence of review and test
13
Risk Management
Patient Safety Risk is Paramount in
Decision Making!
Must be considered in hardware and
software testing
 Explicitly state risk in design docs
 Consider risk in peer reviews

How much testing is optional once the
patient safety requirements satisfied
14