PS Medical® Flow Control Products -- Valves
Strata® Valves
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The PS Medical® Strata® valve is an adjustable flow
control valve in which the resistance properties of the valve
can be
changed non-invasively by the caregiver. It is designed to minimize
overdrainage of cerebrospinal fluid (CSF) and maintain intraventricular
pressure (IVP) within a normal physiologic range, regardless
of patient position. The normally closed Delta® chamber
mechanism opens in response to positive ventricular pressure.
Working with the ball and spring valve mechanism, overdrainage
is minimized by utilizing the principle of hydrodynamic leverage.
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Delta® Valves
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The PS Medical Delta® valve is designed
to minimize overdrainage of cerebrospinal fluid (CSF) and maintain
intraventricular pressure (IVP)
within a normal physiologic range, regardless of
patient position. The normally closed Delta chamber mechanism
opens in response to positive
ventricular pressure. Working with the membrane valve,
this mechanism minimizes overdrainage by utilizing the principles
of hydrodynamic leverage. All Delta valves incorporate a central reservoir dome, occluders for selective
flushing, and a non-metalliic design. The valves are fabricated of dissimilar
materials -- polypropylene and silicone elastomer -- reducing the chance of valve
sticking and deformation. Radiopaque indicators provide an indication of valve-to-catheter
approximation. Delta technology is available in two sizes, four levels, and many
configurations and styles, meeting the specific needs of patient groups, and
physician surgical techniques.
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The Delta valve is designed to minimize overdrainage
of cerebrospinal fluid (CSF) and maintain intraventricular pressure
(IVP) within a normal physiologic range, regardless of patient position.
The normally closed Delta chamber mechanism opens in response to ventricular
pressure. Working with the membrane valve, this mechanism minimizes
overdrainage by utilizing the principle of hydrodynamic leverage.
The Medtronic PS Medical Delta chamber (below) consists
of two silicone elastomer diaphragms, lying flat against two base
outlet ports.
CSF flowing from the ventricles pushes the diaphragm surfaces
away from
the outlet ports, allowing CSF to flow through the ports and out
the distal catheter. In the Delta chamber, the inlet area (shown
in blue) of the diaphragms acted
on by CSF flowing from the ventricles is 20 times greater than
the outlet area (shown in red ) of
the diaphragms
acted on by negative hydrostatic pressure from the distal catheter.
This application of hydrodynamic leverage nearly nullifies any effect
of the negative hydrostatic pressure.
All
Delta valves incorporate an injectable reservoir dome, occluders for
selective flushing, and a non-metallic design. The valves are fabricated
of dissimilar materials -- polypropylene and silicone elastomer -- reducing
the chance of valve sticking and deformation. Radiopaque indicators
provide an indication of valve-to-catheter approximation. Delta valves
are available in two styles, two sizes, and four performance levels,
meeting the needs of most patient groups. To view the performance level
charts, click on the links below:
0
cm Hydrostatic Pressure Performance Levels (Strata and Delta valves)
-50
cm Hydrostatic Pressure Performance Levels (Strata and Delta valves) |
PS
Medical CSF-Flow Control Valves
PS
Medical CSF-Flow Control Valves are available in several models:
Contoured, Burr Hole, Ultra Small, and Button. Each valve is fabricated
of dissimilar materials -- polypropylene and silicone elastomer --
reducing the chance of valve sticking and deformation. A simple,
uniform flow path, combined with the reliable membrane valve design,
ensures optimum valve performance. Every valve is individually tested
to ensure conformance with individual flow characteristics. All
valve designs include integral connectors to facilitate catheter
connection and decrease the possibility of catheter disconnection.
The Contoured, Burr Hole, and Ultra Small models include central
reservoirs with needle guards for percutaneous CSF access. Flushing
occluders are incorporated in the Contoured and Ultra Small models
for proximal and distal flushing. The non-metallic design of the
valves ensures non-interference with MRI or CT scans. Radiopaque
indicators show valve pressure, flow direction, and valve-to-catheter
approximation.