Biomedical Engineering Reference
In-Depth Information
different tube sizes, direct connection of different tube materials, aseptic on-
site manifold fabrication, large and smooth inside bore, no capital equipment
to purchase, and no requirement for power or calibration or service. These
connectors are supplied by Bioquate (
www.bioquate.com
)
.
Welding
When it is possible to use a thermoplastic tube, welding offers an easy, inex-
pensive, and very secure solution. Examples of thermoplastic tubes include
C-Flex, PharMed, and Bioprene. Both thermoplastic tubes must be aseptic,
should have the same dimensions (inner diameter and OD), and should have
their ends capped. The tubes are placed parallel in opposite directions, while
a heated blade cuts through them and seals them simultaneously. Preheating
of the blade is necessary both to achieve the welding temperature and to
sterilize and depyrogenize the blade itself prior to the welding process. The
depyrogenize procedure normally lasts 30 s at 250°C or 3 s at 320°C. After
being cut, the tubes are moved against each other so that the ends of each
tube, which are connected to the aseptic systems, are positioned directly
opposite to each other on either side of the blade. A welding cycle can be
between 1 and 4 min, depending on the material and the diameter of the
