Codman Hakim Bedienungsanleitung Seite 9

ENGLISH
IMPORTANT INFORMATION
Please Read Before Use
Codman Hakim
®
Precision Fixed Pressure Valves
Description
The Codman® Hakim® Precision Fixed Pressure Valve includes a valve
mechanism (Figures 1 & 2) that incorporates a flat 316L stainless steel spring
in which the calibration is accomplished by a combination between a pillar
and a micro-adjustable telescoping fulcrum The valve chassis is made of
titanium Casing and connectors are made of polysulfone The ball and cone
are manufactured from synthetic ruby Intraventricular pressure is maintained
at a constant level by the ball and cone valve seat design
The operating pressures of the valve unit have been determined with
a flow rate of 10–25 ml H 2 O per hour The valve is classified by its
operating pressure with a specified flow rate and not by the opening and
closing pressures The pressure that a valve sustains with a given flow
is the parameter that reflects the operating pressure of the valve once
it is implanted Before shipment, each valve is calibrated with special
equipment Duplication of these test procedures cannot be accomplished
in the operating room
Several models of the valve have been marked with an x-ray detectable
direction-of-flow indicator
Codman Hakim Precision Fixed Pressure Valves are available in the
following preset operating pressure ranges Each valve is calibrated and
tested at the time of manufacture
Precision Fixed Pressure Valve Operating Pressures
10 mm H 2 O
40 mm H 2 O
70 mm H 2 O
100 mm H 2 O (980 Pa)
130 mm H 2 O
The pressure-flow performance characteristics for each preset operating
pressure range as required by ISO 7197 are shown in Graph 1
Graph 1. Average operating pressure range (mm H 2 O) for each preset
operating pressure with active flow through the valve captures
The pressure shown in the graph for each setting is an average range
recorded with active flow through the valve alone at flow rates of 5, 20 and
50 ml/hr; the average operating pressure at 20 ml/hr is shown
®
(98 Pa) Very Low Range
(392 Pa) Low Range
(686 Pa) Medium Low Range
Medium High Range
(1274 Pa) High Range
Flow Rate (ml/hr)
1