Center for Devices and Radiological Health

William Midgette

A PerspectiveOn

Medical Device Risk Management

Heart Rhythm SocietyWashington, D.C.September 16, 2005

Center for Devices and Radiological Health

Two Common Approaches to Analyzing Risk Bottom-up (inductive, e.g., Failure Mode and

Effects Analysis) versus top-down (deductive, e.g. Fault Tree Analysis)

Bottom-up – induce a failure and determine the harm it can cause

Top-down – select an undesired top-level event and identify the faults that can cause it

Center for Devices and Radiological HealthFault-Tree Analysis

Requires the selection of an undesired top-level event, e.g, life-saving shock not delivered for an ICD

The analysis should identify all faults that can cause the event

Risk control measures should be included in the analysis

Center for Devices and Radiological HealthRisk Control Measures

Protective measures, e.g. default operating modes

Information for safety, e.g., warnings in labeling

Many measures require intervention– The correct response for the circumstances, e.g.

a patient-specific response– Timeliness

Center for Devices and Radiological HealthHazardous Situations

Circumstances in which people are exposed to a potential source of harm

Examples of ICD Hazardous Situations– Life-saving shock not delivered– Pacing therapy not delivered

Usually require a “system” of risk control measures

Center for Devices and Radiological Health

Hazardous Situation and Causes

Cause

#1

Cause

#2

Cause

#3

Cause

#4

OR

Hazardous Situation

Center for Devices and Radiological Health

Hazardous Situations, Causes, and Control Measures

Cause

#1 Cause

#2

Cause

#3

Cause

#4

OR

Hazardous Situation

Control

Measure

#1 FailsCntr.Msr.

#2,#3.#4

Fails

AND AND

OR

Center for Devices and Radiological Health

Simplified Example: Part of the Risk Control System for a Hazardous Situation

OR

Alarm

Failure

Sensor

Failure

No InterventionIncorrect

Intervention

Inadequate TrainingConfusing

Instructions

Air Embolism > 0.4mm Enters

Blood Stream

OR

Dialysis System

OR

Center for Devices and Radiological Health

Simplified Example: Part of the Risk Control System for a Hazardous Situation

OR

Premature

Battery

Failure

No Daily

Battery Check

By Patient

No InterventionUntimely

Intervention

Poor

Patient

History

Life-Saving Shock Not Delivered

OR

No

Scheduled

Appt.

Limited Access To

Emergency CareAND

AND

No

AED

Rural

Home

ICD

Center for Devices and Radiological Health

Conclusions