Page 67 - Biomedical Engineering and Design Handbook Volume 2, Applications

46 MEDICAL DEVICE DESIGN

• Detailed assembly drawings
• Manufacturing flowcharts
• Software code
• Packaging specifications
• Labeling specifications
The many interactions of a design project, including prototyping and testing, all go into a design
package that is the basis for the device master record. ∗
(3) Design verification
Design verification is the testing of the design output to ensure that it meets all the requirements
†
in the design input. Of course, this has to be done in using written procedures established and
maintained by the manufacturer.
It is important to differentiate this use of the term verification from the use of the term in man-
ufacturing. Here, it is the design output that is being verified. This is commonly done by all the
bench testing that goes into proving the concept of the design. Each requirement must be tested
to show conformance, for example, pull testing to show tensile strength. Later in the manufac-
turing process, verification and validation are alternate paths to qualifying a manufacturing
process. Here in the design arena, both verification and validation of a design are required.
(4) Design validation
Once all requirements in the design output are verified, the device goes on to the validation
phase. Validation is the process of ensuring that the device works for the purpose for which it
was designed, in the environment for which it was intended. This must be distinguished from the
term process validation, which is used in the manufacturing area as an optional way of qualifying
a process. Design validation must be done on every design. The QSR states:

Design validation shall be performed under defined operating conditions on initial production units, lots,
or batches, or their equivalents. Design validation shall ensure that devices conform to defined user
needs and intended uses and shall include testing of production units under actual or simulated use con-
ditions. Design validation shall include software validation and risk analysis, where appropriate.
Id. § 820.30(g).

As usual, this must be done under a written set of procedures. The results become part of the
DHF.
Methods of validation differ with the type of device. Most lower-risk Class II devices may be
validated in simulated environments on the bench. Some of these Class II devices are validated
in relatively simple user tests in a hospital or doctor’s office. In the type of higher-risk devices
for which FDA expects human clinical data for clearance/approval, the validation is done as part
of the clinical testing. The successful use in a clinical trial validates that the design meets the
defined user needs.
Software validation, a term built into the FDA design validation definition cited above, is yet
a third use of the term validation. This involves establishing a test plan and thoroughly testing
the software. This testing involves a combination of tools which resemble both what are call
verification and validation in the manufacturing regulation. FDA has issued guidance on software
validation which has established some fairly common techniques and procedures used by the
industry.
Once again, the results documenting the successful completion of design validation become
part of the DHF.

∗ Id. § 820.181.
† Id. § 820.30(f).