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Investigation: visual inspection: no significant deformations or damage of the valves were detected during the visual inspection.Permeability test: a permeability test has shown that both valves are permeable.Computer controlled test: to investigate the claim of under-drainage, the opening pressure is measured using a miethke computer controlled testing apparatus which simulates a cerebrospinal fluid flow.The valves are tested in both the horizontal as well as the vertical positions.The results show that the progav 2.0 is operating within the accepted tolerance in the horizontal position.The shuntassistant 2.0 is operating not within the specified tolerances in the vertical position, a slight accelerated outflow was detected.Adjustment test: the progav 2.0 was tested and is adjustable to all specified pressures.Since the shuntassistant 2.0 is a valve with a fixed pressure stage, the adjustment test was not applicable.Braking force and brake function test: the brake functionality test of the progav 2.0 has shown that the brake function is fully operational and the braking force is within the given tolerances.Results first, we performed a visual inspection of the progav 2.0 shunt system.No significant deformations or damage of the valves were detected during the visual inspection.Next, we tested the permeability, adjustability, and opening pressure of the valves, as well as the brake functionality and brake force.The progav 2.0 operated as expected and met all specifications.The opening pressure of the shuntassistant 2.0 was out of tolerance, a slight accelerated outflow was detected, but all other specifications were met.Finally, we have dismantled the valves.Inside both valves we have found some build-up of substances (likely protein).Based on our investigation, we confirm that the shuntassistant 2.0 shows a slight accelerated outflow of liquid at the time of our investigation.This is likely due to the deposits observed inside the valves.Deposits caused by natural substances in the cerebrospinal fluid, such as protein, blood or tissue particles, are among the known and unavoidable risks and side effects of hydrocephalus therapy.We can exclude a defect at the time of release.The shunt system met all specifications of the final inspection when released from christoph miethke gmbh & co.Kg.No further regulatory actions are required from our point of view.
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