||Particles can cause blockage of hydraulic
resistors (see Section 5, Perfusion rate/hydraulic resistors).
||Our resistors that reduce perfusate
flow rates to very low levels have a very fine lumen,
and so are most susceptible to blockage.
||Blockage is prevented by avoiding contamination
with particles and by perfusate filtration.
supplies a purpose-designed filter for perfusion manometry.
Our water filter design has the same shape as the 0.3 micron
gas filter, so must be distinguished from it (see page 60).
The water filter has the marking "Water-20 um". The
Dentsleeve product code is FIL/WA/1.
On Dentsleeve manometric infusion
pumps, this filter connects to the male luer of the reservoir
squeeze clamp assembly outlet.
The 20 micron filter pore size is suited to our entire range
of hydraulic resistors.
Low cost means these filters can be discarded as required to
satisfy infection control requirements.
We recommend de-ionised, degassed water, preferably prepared
by reverse osmosis as this method of reparation greatly reduces
particle load. If this is not available, heat-distilled water
is next best.
Care must be taken to ensure
that the perfusate reservoir is kept meticulously clean and
free of particles.
The perfusate reservoir should be emptied after each
use. If this is not done, algae can grow in the reservoir,
cause clogging downstream, quite apart from infection control
Clogging of the filter is recognised by a poor water jet through
the filter when the perfusate reservoir is pressurised.
Flow through the filter is best assessed with the filter outlet
disconnected from its connection to the manifold.
Filtration capacity needs to be conserved by minimisation
of particle load.
Supplied non-sterile, but autoclavable.