Center for Devices and Radiological Health U. S. Department of Health and Human Services Paul L. Jones Senior Systems / Software Engineer Division of Electronics and Software Engineering Office of Science and Engineering Laboratories Feb 21, 2008 Pros and Cons of Assurance Cases

Center for Devices and Radiological Health 2 Question? Can important & complex information (safety & effectiveness) be communicated more optimally to regulators without placing additional burden on the manufacturer? Assurance Case

Center for Devices and Radiological Health 3 Answer It depends! Topic

Center for Devices and Radiological Health 4 Levels of abstraction Architecture Foundation Plan Floor Plan Framing Plan Wiring Plan Plumbing Plan HVAC Plan

Center for Devices and Radiological Health 5 Assurance Case  Claim  My house is safe  Argument  My house is substantially equivalent to Abe Lincoln’s house  Evidence Sufficient rigor

Center for Devices and Radiological Health 6 (Safety) Assurance Case  Claim  My medical device is safe  Argument  I tested it  Evidence  A test report Sufficient rigor

Center for Devices and Radiological Health 7 (Safety) Assurance Case  Claim  My medical device is safe  Argument  I comply with ISO  Evidence  Conformity assessment letter from Notified Body Sufficient rigor

Center for Devices and Radiological Health 8 A Regulator’s dilemma What is the criteria for an acceptable assurance case? What is the criteria for an unacceptable assurance case? Issues

Center for Devices and Radiological Health 9 TRUST What are the properties of trust?  Trusted abstractions  Trusted components  Trusted compositions  Trustable arguments  Trustable evidence  Trustable changes Issues

Center for Devices and Radiological Health 10 Possible regulatory benefits  Provides a simple framework for reviewing "complex" device designs  Frameworks are persistent (not lost at end of a review)  Possibly use standards more effectively  Frameworks may be used internationally  Communication with mfrs can be more focused (new paradigm for communication) Soft Factors

Center for Devices and Radiological Health 11 Possible regulatory benefits Soft Factors Assurance framework can be extended for changes

Center for Devices and Radiological Health 12 Possible regulatory benefits  Templates can be developed for classes of devices (e.g. GIP, RTP)  Framework may lend itself to automation techniques Future possibilities GIP – Generic Infusion Pump RTP – Radiation Treatment Planning

Center for Devices and Radiological Health 13 Silver Bullet?