This complaint was reopened in reference to (b)(4).Investigation: we received the valve in a plastic container.The valve was inserted in an unknown liquid.The progav was set to pressure range 8 cmh2o at the time of delivery.Optical inspection: first step of our investigation is the optical inspection.The visual inspection revealed that the valve has no apparent deformations or other abnormalities.However, the measurement of parallelism has shown, with a measured value of -0,0715 mm, that the valve is outside the accepted tolerance.Result: in the visual inspection of the valve, we could not detect any apparent damage.Nevertheless, the measurement of the parallelism could confirm a deformation.In the further course of investigation we carried out a permeability test.The investigation has resulted that the valve was permeable.However, it was not possible to adjust the valve.To proof if the brake function is full in place, despite the deformation observed, we carried out a brake function test.The investigation has shown that the brake function is present, but it was not possible to measure the braking force due to the non-adjustability.In order to verify whether the valve examined here has been influenced by the known risks of hydrocephalus therapy, for example by natural substances in the cerebrospinal fluid (protein, blood or tissue particles), we have finally decided to dismantle the valve.Inside the progav-valve we have found apparent deposits or substances of protein which might could be the reason for the assumed difficulties in adjustability in the past.Based on our investigation results we can confirm that it was not possible to adjust the progav valve.This is presumably due to the found deposits inside the valve and probably less due to the fact that the valve is deformed.But at the time of delivery there is no failure detectable with this progav valve.No further actions required.
|