MEDICAL
WAVE SPRINGS FOR
MEDICAL APPLICATIONS
Design engineers
in the medical sector are
constantly innovating to improve
patient care. Here Simon Ward, technical
manager at leading fastening and fixing supplier
TFC, explains how designers can reduce the size
of their devices with wave springs.
There are more than
500,000 medical
technologies on the
market, from thermometers
to mechanical ventilators.
Products typically have a
short lifecycle of around
18 to 24 months before an
improved version becomes
available, in fact.
One example of rapid
innovation is wearable
technologies, which are now
available to track everything
from patient blood pressure
to walking gait, electrolyte
levels and heart rhythms.
Across the board, we are
seeing innovation in tools and
technology for prevention,
diagnosis and management
of diseases. As the use of
digital technology in medical
applications rise, engineers
are designing new, innovative
CHOOSING A
WAVE SPRING
Crest-to-crest wave springs
are one option for medical
applications requiring lower
spring rates. Another precise
and reliable option is a singleturn
wave spring, which
is useful if the application
involves short deflections
and low-medium forces. If a
straight load bearing system
products to aid patient welfare.
When innovation makes
technology more complex,
design engineers are often
challenged with device
size, particularly when
integrating all the mechanical
components into a practical
size. For example, traditional
coil springs may be too large
for medical technologies that
are designed to be small and
lightweight — causing the
design engineer to consider
alternatives.
WHAT ARE SPRINGS
USED FOR?
Springs are used in numerous
medical products. They are
commonly used as a return
spring on a function button
— they can also be used to
maintain electrical contact or
to compensate for assembly
tolerances. Traditionally, coil
springs have been used in
these applications, but the
tides are beginning to turn.
An alternative option is a
crest-to-crest wave spring,
which like coil springs apply
force axially when compressed.
Wave springs are a great space
saving technology, as they
require less than half of the
space needed for a coil spring
— providing the same spring
force at a smaller operating
height. This in turn reduces
the spring cavity, which is
helpful when working with
tight space constraints.
Wave springs can therefore
be a great asset to a designer
of handheld instruments and
tools, or wearable devices,
who is looking to design a
lightweight, compact and
balanced product.
14 Issue 4 2020