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Visual inspection: during the investigation, scratches on the outer housing of the valves, but no significant deformations or damage were determined.Permeability test: a permeability test has shown that both valves are permeable.During the permeability test bloody liquid were flushed out.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 operate within the permissible tolerance in their respective relevant position.Adjustment test: during the adjustment test it was determined that the progav 2.0 but not the m.Blue is adjustable in all pressure ranges.Braking force and brake function test: the brake function test has shown that the brake function works as expected with both valves and that the braking force of the progav 2.0 is within the specified tolerances.Internal inspection: after dismantling of the valves, deposits were found in both valves.Results: based on our investigation results, we can determine that the m.Blue is not adjustable.The deposits visible in the valve are the cause of the functional impairment.Deposits caused by natural substances in the 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 proteins can impair the integrity of the valve.Furthermore, we can detect visible deposits in the progav 2.0.These deposits did not affect the technical properties at the time of testing.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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