environment allowed for fault injection.
Fault injection is a technique where the
effectiveness of tests and diagnostics
can be assessed by creating simulated
faults and seeing the effect of it on the
system. We also used programmable
signal generators to simulate abnormal
sensor inputs and conditions.
Managing Risk / Risk Analysis
It is important to understand the difference between verification and validation. Verification tests that the product
meets the specifications/requirements
as written. Verification answers the
Figure 2. Software segmentation within a typical medical device
• Did we build the product as we
• Is it bug-free?
Validation ensures that the product
meets a real need and that the right
product is built. This can only be done
in a clinical setting when you have a
heart pump actually pumping blood
through a patient.
Software verification and validation
is only one portion of the overall equa-
tion. To increase confidence in safety
and reliability measures, all aspects of
the software development life cycle
must be monitored for compliance with
applicable requirements, standards,
procedures, and regulations. This can
only be accomplished through rigorous
quality assurance activities.
Risk analysis and providing traceability must be performed at all stages
of the development process: user
needs, detailed functional requirements, architecture, design, reviews,
verification, test cases, defect reporting,
contingency, and next step planning.
This management is a mandated
requirement whether a traditional
waterfall or more iterative approach
is used for the software development.
Impact analysis and version history
must be complete.
FDA Submission and Approval
Our client submitted to the FDA for
510(k) clearance and we are pleased
to say that it was approved without
any conditions or comments. It was
quite unusual that the FDA had no
comments on software for a Class III
device. Normally when you do an FDA
submission on any device that has
software, most of the issues are around
In conclusion, software is a major risk for medical devices and can
complicate getting FDA approval. A
systematic approach to verification and
traceability analysis can help you prove
to the FDA that you have tested your
system against regulatory standards and
it meets clinical needs without unnecessary patient safety risk. MDT
Figure 3. A flow chart of the development process
Va da on li i t
Fucoa i l nt n
R q irem s e u ent