Sophysa SiphonX Manual De Instrucciones página 5

The SiphonX® gravitational anti-siphon device (Figures 1&2) is a single use
implantable device.
The SiphonX® enables additional resistance to be added to the operating pressure
of a CSF drainage valve.
The SiphonX® is placed downstream of the shunt valve so that the CSF arrives in the
anti-siphon device from the valve through the inlet connector [1]. It then passes into
the body of the anti-siphon device [3] and leaves it through the outlet connector [4].
On the body of the device an arrow [2] shows the direction of CSF fl ow through the
device. This helps to position the SiphonX® correctly during implantation.
Above this arrow is a unique serial number [5].
The operational principle of the SiphonX® gravitational anti-siphon device is based
on the resistance to the fl ow exerted by the weight of tantalum weighting ball [6],
which presses on a ruby ball [7]. This ruby ball [7] occludes the aperture for the
passage of the CSF [8].
The operating pressure of the SiphonX® gravitational anti-siphon device is determined
by the inclination of the device from the vertical axis.
When the SiphonX® is in the horizontal position, the ruby ball is not subjected to the
weight of the tantalum ball and so does not occlude the aperture [8] of the device.
The SiphonX® is therefore open and does not add any additional resistance to the
operating pressure of the valve (Cf. Figure 3).
Figure 3: The SiphonX® in horizontal position : open
When the SiphonX® is in the vertical position, the ruby ball is subjected to the full
weight of the tantalum ball, occludes the aperture (Cf. Figure 4) and the device adds
200mmH 0 to the operating pressure of the valve.
2
Figure 4: The SiphonX® in vertical position : closed
If the pressure applied to the shunt exceeds the sum of the operating pressures of the
valve and the anti-siphon device, the device opens: the CSF pushes the ruby ball and
the weighting ball and fl ows through the outlet connector (Cf. Figure 5).
Figure 5: The SiphonX® in vertical position : open
For example, for a valve set to 110mmH
assembly is 110+200 = 310mmH
110+0 =110mmH 0 for a patient in the horizontal position.
2
For all intermediate inclinations between the horizontal and the vertical, the
SiphonX® adds a resistance which depends on the angle of inclination (Cf. Figure 6).
Figure 6: Operating pressures for the SiphonX®, SX-200 model, depending on its
inclination, whatever the flow rate between 5 and 50ml/h
This curve is obtained by applying the following method: the measurement concerns
the upstream pressure of a 10ml/h fl ow of water passing through the SiphonX®
and the Sophysa proximal and distal catheters and by varying the angle from
0° (horizontal) to 90° (vertical). The same curves are obtained for fl ow rates between
5 and 50ml/h.
The measurement is performed disregarding the resistance of the catheters.
5
0, the resistance of the "Valve + SiphonX®"
2
0 for a patient in the vertical position and
2
Angle (°)