MIETHKE GAV, Руководство для пациентов

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17
PATIENT HANDBOOK
GB
x = opening pressure in horizontal position
1 ventricle container
2 ventricles
3 drainage tube
4 abdominal cavity
5 abdominal container
6 GAV
Fig. 8: Ventricle drainage with GAV
a) horizontal, b) vertical
x
a) 1 2 3 4 5
2
3
4
0
1
6
5
b)
TECHNICAL SPECIFICATIONS OF THE VALVE
Fig. 9: Schematic cross section of the GAV
(see inner cover page)
a) ball-cone valve
b) gravity valve
1) coding ring
2) coil spring
3) tantalum ball
4) sapphire ball
The
GAV
uses gravity to adjust, regardless of the
patient’s position, a ventricular pressure guided by
pressure values as in a healthy person. A ball-cone
valve controls the ventricular pressure when the
patient is lying down. As soon as the patient rises,
a heavy tantalum ball is brought into action which,
through its gravity, adjusts the valve to a higher
opening pressure. The closer the upper body of
the patient gets to the vertical position, the higher
becomes the opening pressure of the GAV . This is
necessary, because the height difference between
the ventricles of the brain and the abdominal cavity
increases, see ”Physics background”.
The GAV is made only of high-grade materials
which have been tested and standardized for use
as implant materials, the main material being tita-
nium. The solid casing reduces external influences
(e.g. external pressure) on the functioning of the
valve to a negligible minimum. Hence a high level
of functional reliability and a long service life are
guaranteed.
Fig. 10: GAV, scale 1:1
27,4 mm
Ø 4,6 mm
Warning note: The shunt system may comprise
a reservoir that can be pumped. Since frequent
pumping may lead to overdrainage and thus
to very unfavorable pressure conditions, such
pumping should only be carried out by the phy-
sician.
PATIENT ID
Each GAV is delivered with a Patient ID which is fil-
led out by the attending physician. This document
will then hold important information for follow-up
examinations.