Visual inspection: in the first step of our investigations, an optical control is carried out.It is checked whether any defects, deformations or other noticeable irregularities can be identified.Permeability test: to proof the penetrability of the valves we have carried out penetrability tests.These tests are carried out at a calculated hydrostatic high (open pressure of the valves + 30 cmh2o) in horizontal direction of flow.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 by simulating a cerebrospinal fluid flow at rates between 60 ml/h down to 5 ml/h and up again to 60 ml/h with the valves in both vertical position and horizontal position (in acc.To iso 7197).Distilled water is used as the test-liquid.Adjustment test: the adjustment test is used to ensure that the proga_v 2.0 can be adjusted to all pressure levels.The tests are carried out with the standard progav 2.0 checkmate and measurement tool.The valve is adjusted from 0 to 20 cmh2o and down again in increments of 5 cmh2o.Braking force and brake function test: to measure the braking force, we tested the progav 2.0 valve with a braking force apparatus.Here it is measured how much force must be exerted on the housing to release the rotor to adjust the valve by the integrated magnet of the braking force apparatus.Results: it should be noted that the shunt system was received dry (i.E.Not submersed in liquid as recommended).The investigation of dry items is not significant due to the affect dry deposits of liquor and blood can have on product performance.In spite of this, we have investigated the system to the best of our abilities.No significant deformations or damage of the valves were detected during the visual inspection.Next, we tested the permeability and opening pressure of the valves.Both valves were shown to be permeable and their opening pressures were operating within specifications.Additionally, we tested the adjustability as well as the brake functionality and brake force of the progav 2.0 valve.The valve operated as expected and met all specifications.Finally, we have dismantled the progav 2.0.The shunt assistant 2.0 was not dismantled because there was no reason for complaint and no deviations in the product could be observed during the investigation.There were no visible deposits observed inside the progav 2.0.Based on our investigation, we are unable to substantiate the claim of under-drainage and non-adjustability.At the time of our investigation, the progav 2.0 was able to be adjusted to all specified settings and operates to all specified tolerances.At the time of the investigation we are not able to determine how the functional impairment mentioned above occurred in the past.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.
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