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Medical Electronics: The
Delicate Job of Connecting Man to Machine
By
Dr.-Ing.
Kurt Woelfl, ODU
A sterile working environment—used on
or in the body—and special ambient conditions, such as strong
magnetic fields, place special demands on connectors. Perfect
shielding, shock protection, and endurance after tens of thousands
of mating cycles are only a few of the product features mandated in
the field of medical electronics.
Worldwide, roughly three percent of all connectors are manufactured
for medical electronics applications— representing a respectable
$1,158.4 million. The requirements placed on internal connectors,
for example, card-on-card or connector assemblies, are almost
identical to those in general industrial electronics or machine
construction. Significant differences apply, however, to so-called
interface connectors; i.e., the connectors that connect the medical
device directly to the medical “tool,” such as the bone saw, the
electric scalpel, the catheter, or the defibrillator—or to the
patient. These special demands result not only from requirements
related to the function of the connectors, but are also due to
sterilization of cables and connectors, and the use of the
connectors on or in the body.
Connectors play a pivotal role in medical electronics because they
constitute the interface between man and machine.
Connectors are used in diagnostic systems, such as magnetic
resonance scanners, patient monitoring systems, or endoscopes. They
are also used in the therapeutic arena, such as in optical surgical
devices, cardiac support systems, catheters, and defibrillators.
There are machine-oriented and patient-oriented connectors.
Typical examples of machine-oriented connectors in diagnostics
include connectors for patient coils in magnetic resonance imaging
(MRI) devices.
Patient-oriented connectors come into contact with the body of the
patient and can become bloody during use, such as in endoscopes,
catheters, or cardiac support systems. Particularly for these
connectors, special materials must be used, as the systems—including
the connectors—must be sterilizable.
An example of machine-oriented connectors are those used in MRIs. ODU
is one of the leading
manufacturers of interface connectors for magnetic resonance
scanners. This interface connector connects the individual body
coils (antennas) to the main device.
Here we are talking about a large number of (up to 32) RF signals
that must achieve extremely high signal quality across a broad
frequency range and under extreme conditions (a strong magnetic
field and up to 60,000 mating cycles; subject to drops of 1.5 meters
onto concrete, etc.). Look to a manufacturer whose strengths are in
the medical arena for confidence in designing medical products.
 ODU's
interface connector in this MRI
device features non-magnetic contacts, 64 coding possibilities,
operates to one gigahertz, and more than 50,000 mating cycles.
Connectors used in cardiac support
systems are an example of patient-oriented connectors. With cardiac
support systems, a distinction must be made between extracorporeal
and implanted systems. Both systems have very demanding requirements
for the connector systems used within them. With implanted systems,
an artificial heart pump takes over the cardiac activity and helps
bridge the waiting period until the patient receives a donor heart.
Connectors ensure the supply of electricity to this artificial heart
pump. An important factor in these systems is keyhole, or minimally
invasive, surgery, in which the connectors for the power supply must
be as small as possible. ODU has developed a system that is not only
small but also extremely reliable. For this highly specialized
application, special materials are used. The connector is designed
to be shielded and shock-protected, and to allow blind-mating
(foolproof).
 Particularly
in medical electronics, customer-specific solutions are frequently
necessary. Often, a standard connector is not suitable and the
medical device manufacturer cannot, and will not, settle for an
approximate solution, but instead demands a connector system that is
tailored precisely to the requirements of the particular
application. Individualized solutions are then developed in close
cooperation with the customer, ensuring that the customer receives a
connector that is perfectly matched to the application and that can
perform all of the required functions without compromise.
A recent development observed in medical electronics is the trend
towards disposable products. It is often cheaper to use a new system
than to sterilize or autoclave an existing one. The attached
connector system ends up in the landfill then as well.
Yet, despite all trends towards smaller, better, and cheaper
connectors, quality remains a deciding factor—even for disposables.
If a product or a system is used only once, it must be inexpensive.
On the other hand, it must function with absolute reliability. This
dichotomy between higher quality and lower price is the real
challenge for manufacturers of connectors.
To meet this challenge, manufacturers must develop connectors that
are affordable, yet at the same time offer a high standard of
quality. ODU’s disposable connector products are delivered as a
system solution; i.e., the customer receives a complete system
(connector with cable, packing, and over-molding).
The trend in medical electronics is
basically the same as in other markets: Namely, more and better for
less. Depending on the exact application, what defines more (more
signals, higher voltage, etc.) and better (higher quality, smaller
size) varies, but what defines less (shorter development time, lower
costs) is usually the same.
Seek a supplier who focuses on innovative and customer-specific
solutions, and is familiar with medical interconnect trends and is
able to respond effectively.
Medical electronics is currently experiencing a pioneering role in
the technology world. This is no different with connectors. The
know-how we gain from medical electronics can be applied in many
other areas and thus contributes to success in all technical fields.
Visit ODU online.
Dr.-Ing. Kurt Woelfl
is the executive director of ODU in Mühldorf, Germany. He began his
career at BMW in 1995. He served as plant manager at
Dräxlmaier in 1998,
and joined ODU in 2001. Dr. Woelfl has a Ph.D. in robotics from the
University of Technology, Munich, a MBA from the University of
Texas, Pan American, and aeronautical and aerospace engineering
degrees from Stanford University.
ODU Steckverbindungssysteme GmbH & Co. KG,
Otto Dunkel GmbH
Pregelstraße 11
D - 84453 Mühldorf
Tel.: +49/8631/6156-0
Fax: +49/8631/6156-49
E-mail: zentral@odu.de |
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