Bayer Plastics Makrolon® Polycarbonate Resin Selected For Breakthrough Cardioplegia Device

“The small size of the VBC unit and thus the need
for much less blood to prime the system is a breakthrough,” said Daniele Ghidoli,
project engineer at Gish Biomedical, Inc.  “The unit provides complete visibility
of the blood path and excellent heat exchange efficiency.”

The VBC device requires only about 45 ml to prime,
handles blood flow up to 600 ml/min, and has an integral bubble trap, particulate
filter and temperature port.  The structural strength, biocompatibility and clarity
– it is critical for the perfusionist to be able to see how the blood is flowing
and to see if there are any bubbles in the blood – are provided by a medical grade
of Makrolon® polycarbonate from Bayer Plastics.

Gish Biomedical and its molder, Ambrit Engineering
Corp., selected Makrolon polycarbonate to manufacture the VBC unit because the
Bayer resin offers a combination of clarity, dimensional stability and ease of
processing, as well as meeting the requirements of FDA-modified ISO 10993, Part
1 “Biological Evaluation of Medical Devices.” 

Only products
that meet these requirements may be considered for applications – like the VBC
– requiring biocompatibility.  Another important aspect of this Makrolon resin
grade is the ability to be sterilized using radiation, ethylene oxide, or steam
autoclaving. Makrolon resin’s physical and molding properties also made it the
right material for the application.

“We have very tight requirements with regard to
dimensional stability,” Ghidoli said.  “For example, the inside surface has to
be very close to the heat exchanger to reduce the likelihood of shunting and to
assure the most efficient cooling or warming of the blood.”

The VBC unit is molded in two parts.  One part
is shallow, and is molded with a blood inlet port, blood outlet port and a pressure
relief port.  The part also has a temperature port connected to the blood outlet
port; a stainless steel part is insert molded in the temperature port.

The second part is
deeper, forming the housing for the heat exchanger, and has two half-inch universal
water connectors, as well as the integrated bubble trap on the top, which has
a pressure monitoring and vent port.  Both parts are formed in a single family
mold.

During assembly of the VBC, the stainless steel heat
exchanger and the blood filter are installed, and the two plastic parts are joined
using UV bonding.  The resulting unit is just 5 inches high, 3 inches wide and
2 inches deep.

“The whole unit is basically four pieces – the two
polycarbonate parts, the blood filter and the heat exchanger,” Ghidoli said. 
The VBC units are sterilized using ethylene oxide and supplied in sterile packs
with various configurations of tubing attached, to meet the needs of a particular
surgery.

Consistency and Ease of Use

Ambrit Engineering has worked with Gish for many
years, and is experienced in using Makrolon resins.

“Gish asked us to participate in development of
the VBC when it was in the design stage, evaluating the different kinds of materials
that could be used,” said John Mattimoe, Ambrit’s president.  “We build the tooling
and do the molding, so we also worked with Gish on the design of the parts, since
that would affect the design of the mold and the way it would fill.”

Mattimoe said his company recommended Makrolon
because the configuration of the parts is non-uniform – an upper and a lower housing
that are quite different in shape. 

“Even though the two parts are non-symmetrical,
they have a tongue-and-groove joint that has to match up perfectly, so polycarbonate
is the ideal candidate,” Mattimoe said.  “We knew that with Makrolon we would
be assured of a reliable shrinkage factor.  The material also has a wide processing
window, which allows us to have more latitude in molding a complex part like this.”

Mattimoe said the VBC project was completed on
a tight deadline, but with excellent results.  “The project was done in just under
ten weeks, which for a mold of this complexity was pretty fast,” he said.  “It
worked right off the bat.”

For more information on medical devices, contact
Gish Biomedical, Inc., at 1-800-938-0531, or visit their Web site: 
https://www.livanova.com/en-US/.

For more information on custom molding, contact
Ambrit Engineering Corp. at 714-557-1074.

For more information on Bayer Plastics and Makrolon
polycarbonate resins, contact 1-800-662-2927 or visit
www.bayerplastics.com.

Headquartered in Pittsburgh,
Bayer Corporation had sales of $10.1 billion in 2001 and is one of Fortune magazine’s
Most Admired Companies. The company employs 21,500 people. It is a member of the
worldwide Bayer Group, a $27 billion international health care and chemicals group
based in Leverkusen, Germany.  Bayer’s four operating companies – CropScience,
Chemicals, HealthCare and Polymers – produce a broad range of products that help
diagnose and treat diseases, purify water, preserve local landmarks, protect crops,
advance automobile safety and durability and improve people’s lives.

The Bayer Group has nearly 128,000 employees. 
Its stock is a component of the DAX and is listed on the New York Stock Exchange
(ticker symbol: BAY).  For 2001, the group recorded sales of EUR 30.3 billion
and a group net profit of EUR 965 million.  Capital expenditures totaled EUR 2.6
billion, and EUR 2.6 billion was invested in research and development.

This news release contains forward-looking statements
based on current assumptions and forecasts made by Bayer Group management.  Various
known and unknown risks, uncertainties and other factors could lead to material
differences between the actual future results, financial situation, development
or performance of the company and the estimates given here.  These factors include
those discussed in our public reports filed with the Frankfurt Stock Exchange
and with the U.S. Securities and Exchange Commission (including our Form 20-F). 
The company assumes no liability whatsoever to update these forward-looking statements
or to conform them to future events or developments.