Page 243 - Safety Risk Management for Medical Devices

222 Safety Risk Management for Medical Devices

to create functional and design boundaries between the safety-critical parts of the
System and the rest of the System and create firewalls to limit the impact of the latent
design defects.
In the course of regulatory review of the medical device submissions, the device
design, particularly the safety aspects of the design become scrutinized. A well-
architected System with clear and simple safety subsystems would be more easily
reviewed, with fewer questions, and gets approved more quickly.

31.1 IDENTIFICATION OF ESSENTIAL DESIGN OUTPUTS

CFR Title 20, Part 820.30 [35] states that “Design output procedures shall contain or
make reference to acceptance criteria and shall ensure that those design outputs that
are essential for the proper functioning of the device are identified.”
It can be stated that Essential Design Outputs (EDOs) are those design outputs,
which are essential to the safety and efficacy of the medical device.
The term “design output,” which is referenced in 21 CFR 820.30(d), can have
different meanings. A design output is the result of design efforts at each phase, and
also at the end of the total design effort. Therefore there can be intermediate and final
design outputs.
The FDA defines finished design output as the basis for the Device Master Record
(DMR); and defines the total finished design output of the device, as the device itself
plus its packaging, labeling, and the DMR.
So, what are EDOs? Why do they matter? And, once we identify them, what are
we supposed to do about them? Let’s answer each question in turn.
1. EDOs are element of the actual finished design output whose loss or degrada-
tion would have an adverse impact on the safety or proper functioning of the
device. For example, a particular dimension on a part, or a component itself
could be EDOs.
2. EDOs matter because they are essential for the “proper functioning” of the
device; meaning safe and effective functioning of the device.
3. Once EDOs are identified, certain policies should be exercised to provide
higher confidence in the implementation and performance of those outputs.
This could be in the form of increased process capability requirements, tighter
QC inspections, etc.

So, what role does risk management play for EDOs? As stated earlier, EDOs are
critical for the safe and effective functioning of the device. Risk management is con-
cerned with safety, and can assist the product design process in the identification of
EDOs. Fig. 31.1 presents a strategy for the identification of EDOs from a safety