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Visual inspection: during the investigation, no significant deformations or damages of the valves were determined.Permeability test: a permeability test has shown that both valves are permeable.Computer controlled test: to investigate the claim of over-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 position.The results show that the valves do not operate within the permissible tolerance in their respective relevant position.An accelerated outflow of progav 2.0 and a slower outflow of the m.Blue could be determined.Adjustment test: the valves were tested and the m.Blue is adjustable, but the progav 2.0 is not adjustable to all pressure settings.Braking force and brake function test: the brake functionality test has shown that the brake function of the m.Blue operates as expected and the braking force is within the given tolerance.However, the brake function of the progav 2.0 operates as expected, but the braking force cannot be measured due to the non-adjustability of the valve.Internal inspection: after dismantling of the valves, organic deposits were found.Results: according to the results of the investigation, a reduced outflow of the m.Blue was detected.Furthermore we found the progav 2.0 was no longer adjustable and had an accelerated outflow.The visible deposits in the shuntsystem have led to the functional deviations.We can determine visible deposits in the control reservoir.The deposits had no effect upon the specifications at the time of the examination.Deposits caused by substances naturally present in the patient's body, such as protein, blood or tissue particles, are among the known and unavoidable risks and side effects of hydrocephalus therapy.Even small amounts of organic material can affect the integrity of the valve.The examination of the return has been completed with the drafting of this report.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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