Medical Design Briefs - January 2024 - 20

TECHNOLOGY LEADERS Electrical Connectors/Wires/Cables
each test can be modified in order to obtain
data of a variable (numerical) type,
which may help to reduce the sample size
needed in order to achieve the desired
confidence intervals. For some tests, e.g.
sub-atmospheric pressure air leakage,
the change is trivial, only requiring one
or two additional calculation steps.
For others, like the positive pressure
falling drop liquid leakage test, the apparatus
used to perform the variable test
method requires additional levels of
control beyond what is needed to perISO
594 Test
ISO 80369-7 Test
Equivalent
Leakage by
Liquid
Leakage
Falling Drop
Positive Pressure
Liquid Leakage
Sub-Atmospheric
Pressure Air Leakage
Air
Leakage
There aren't significant changes to the
Separation Force
Unscrewing
Torque
Ease of
Assembly
Resistance to
Overriding
Stress
Cracking
Resistance to
Separation from
Unscrewing
None
Resistance to
Overriding
method; however, the acceptance criterion is
more specific in ISO 80369, which specifies
that the interface between the connectors
should not detach.
The ISO 80369 test resembles the ISO 594 test
without significant changes to the method.
The ease of assembly test was not included in
ISO 80369 because the analysis was too
dependent upon test operator subjectivity.
The ISO 80369 test resembles the ISO 594 test
without significant changes to the method.
Stress Cracking
The stress cracking preconditioning has not
changed significantly; however, the method of
detecting cracks has changed. In ISO 594, a
visual inspection was performed. In ISO 80369,
one the two fluid leakage tests is performed in
order to reduce the subjectivity of the test.
Table 3. Many of the tests have changed substantially. This table compares and contrasts some of the most
significant changes to each test.
Pressure Decay
form the attribute test method. The determination
of whether or not to utilize
the variable methods is typically made
on a case-by-case basis and takes into account
the potential extra test method
validation work, fixturing, and increased
cost for tests that require more time and
complex equipment to perform.
Is Non-Interconnectability Testing a
Requirement?
ISO 80369-1 states that small-bore
connectors of each application category
COMMENTS
This is a new test, which utilizes a pressure
decay leak tester in order to determine the
pressure decay rate of the connection using
air as the medium. The fluid leakage requirement
in ISO 80369 is satisfied by performing
either this test or the falling drop positive
pressure liquid leakage test.
The ISO 80369 test resembles the ISO 594 test
without significant changes to the method.
Rather than pulling a vacuum using a syringe
and monitoring for formation of bubbles, ISO
80369 specifies the vacuum pressure applied
to the connectors and the rate of pressure loss
is recorded. Use of a pressure decay leak tester
is preferred for this test.
shall be non-interconnectable with any
of the small-bore connectors of every
other application category, unless otherwise
indicated in ISO 80369-1 or within
the ISO 80369 series. Based on this,
manufacturers will need to demonstrate
that the small-bore connector under test
exhibits non-interconnectable characteristics
when evaluated against connectors
of other application category, in
addition to ensuring that they safely and
securely connect with their mating half.
If a small-bore connector meets the dimensional
compliance and modulus of
elasticity compliance within the requirements
of the various application parts of
the ISO 80369 series, it is considered
sufficient objective evidence of noninterconnectable
characteristics. If a
small bore-connector does not meet
both of these requirements, then the
methods of ISO 80369-1 are to be used.
There are two different ways to show
that a small-bore connector meets the criteria
of non- interconnectability per ISO
80369-1. The first is to run a dimensional
analysis comparing all of the different
parts of the connector to other connector
application types. Annex B.2 in ISO
80369-1 provides detailed instructions
regarding how to perform this dimensional
analysis. It takes into consideration
the least material condition (LMC) and
maximum material condition (MMC) of
all of the parts to ascertain whether they
will incidentally connect when assembly
of the parts is attempted.
If it is determined through this dimensional
analysis that a part could connect
to a different small-bore connector, the
feature, or as the standard calls it the
" potential mating surface, " which a given
part is being evaluated against would
need to be created and then tested in
the physical test in Annex B.3. The mating
surface needs to comply with the material
requirements in Annex B.2 to be a
valid part to test against.
The second method to show that a
sample meets the criteria of non-interconnectability
is to run the physical
tests that are described in Annex B.3
of ISO 80369-1 against a target reference
connector. The target reference
connector is either determined from
Annex B.2 or other connections as
identified by the manufacturer. In
20
www.medicaldesignbriefs.com
Medical Design Briefs, January 2024

http://www.medicaldesignbriefs.com

Medical Design Briefs - January 2024

Table of Contents for the Digital Edition of Medical Design Briefs - January 2024