Page 286 - Safety Risk Management for Medical Devices

APPENDIX C: EXAMPLE DEVICE—VIVIO

In this appendix, the BXM method is applied to a hypothetical Automatic External
Defibrillator (AED) named Vivio. The purpose for this example is to teach by illustra-
tion, the mechanics of the BXM method. Vivio is not a real device. The cited elec-
tronics and mechanical designs, or the Failure Modes or mitigations are not from a
real device. Use the example as a vehicle to learn how risk management is done per
the BXM method, and how the different elements of risk management are connected
to one another.
The Vivio example is deliberately simplified and abbreviated to ease comprehen-
sion by the reader, and also to fit within the bounds of this book.
• Only System-level Failure Modes and Effects Analyses (FMEAs) are provided:
System Design Failure Modes and Effects Analysis (DFMEA), System Process
Failure Modes and Effects Analysis (PFMEA), and Use-Misuse Failure Modes and
Effects Analysis (UMFMEA). Lower level FMEAs are presumed to be performed
as needed.
• Only some of the Failure Modes with safety impact are carried forward to the Risk
Assessment and Control Table (RACT). In a real project all Failure Modes in System-
level FMEAs that have a safety impact should be carried forward to the RACT.

C.1 VIVIO PRODUCT DESCRIPTION

Vivio is an AED. It is small, lightweight, rugged, and battery operated. Vivio is
intended for simple and reliable operation by minimally trained people.
Vivio is intended to treat Ventricular Fibrillation (VF), the most common cause
of sudden cardiac death (SCD). VF is a chaotic quivering of the heart muscle that
prevents the heart from pumping blood. The only effective treatment of VF is defi-
brillaiton, which is sending an electric shock across the heart, so as to reset the
heart and enable it to start pumping again. A victim of VF is genrally unconscious.
When properly applied, Vivio automatically senses, and diagnoses the victim’s heart
rhythm, and if VF is detected, Vivio delivers a high voltage electric shock to the
victim’s heart.

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