VP shunt systems are programmed proGAV

The principles of working proGAV


Şekil-1. ProGAV mechanism

MIETHKE proGAV position is a dependent valve.The opening pressure of valve changes according to patients position otomotically.When a proGAV put into practice;pressures are conditioned of the patients such as horizantal and vertical position.

Horizantal Position

Şekil-2 Gravitasyonel ünit

The pressure of the body’s of patient working pressure is determined by the adjustable unit of valves.Gravitational ünit has no effect on the working pressure.Woking pressure of the valve is adjusted while after the determinig of patients suitable values between the 0 and 20 cmH2O(21 steps).

If the patient is horizantal position,the gravitional unit sopn all the time,it does not disrupt to flow of BOS.(figure 2)In the figure of 3 and 4 shows the function of adjustable unit.


Şekil-3 Adjustable unit and valve-close

Şekil-4 Adjustable unit and valve-open

Vertical Position

When the patient is afoot,gravitional unit is closed.For this reason pressure of the proGAV get by the high functional grade and happens the BOS dreinage.(figure 5)the total of intraventicüler pres and hydrostatic pres drive through the second step of proGAV,dreinage starts reagain.(figure6).In the vertical position the working pressure of proGAV equals the total pressure of adjustable unit and gravitional unit.

Gravitional unit Şekil-5 close Şekil-6 open

Value of the pressure of proGAV

Standard	Smart unit	Gravitional unit
Above the lenght of 1.60 and active patients until 60 years old	0 - 20 cm H2O	25 cm H2O
Until the 5 years of child and above 60 years old patients	0 -20 cm H2O	20 cm H2O