ISO 7197:2006 pdf download – Neurosurgical implants -Sterile,single-use hydrocephalus shunts and components
ISO 7197:2006 pdf download – Neurosurgical implants -Sterile,single-use hydrocephalus shunts and components.
4.5 Control of the implanted shunt
The functionality of the shunt and the method of control of the implanted shunt shall be stated in the accompanying documents,
If no test Is possible, the manufacturer shall state this fact In the instructions for use and the accompanying documents.
4.6 Pressure-flow characteristics of the valve, the components and the pre.assembled shunt
The pressure-flow diaractenstics of the valve shall be tested and monitored in the relevant flow range of (5 to 50) mllh, A graph showing the pressureiflow characteristics shall be included in the accompanying documents.
The manufacturer shall state if the complete system (catheter, reservoir and other devices) causes fundamental changes in the pressure/flow characteristics. In this case, graphs showing the pressure/flow characteristics of the complete shunt and the components shal be included.
NOTE Fundamental change would be additional resistance due to an inner dierneter of the catheter smaller than 1 mm (see 5.2).
It the device shows a posture-dependent function, the basic characteristic for the most important positions should be shown (see 5.1.3).
If the characteristic of the device depends on the subcutaneous pressure, the effects on the valve performance should be shown in the relevant ranges (see 8.2 9)].
4.7 IdentificatIon of shunts In vivo
The type of the valve as well as the direction of flow shell be detectable non-invasively. A method for the idenbtlcatn of the valve shall be given in the instructions for use and In the patient identification card. For adjustable devices, an X-ray image related to the basic understanding of the pressure settings shall be included in this information.
4.8 AbIlity to withstand overpressure
The functionality and integrity of the shunt shal not be affected by 9.806 7 kPa (1 m water column) positive
pressure applied to the open shunt.
4.9 Dynamic breaking strength
The dynamic breaking strength of every component of the shunt shall be tested using a frequency of (1 ± 0,2) Hz. The tension shall be applied in flow direction and lead to an elongation of the shunt of 10 % or a maximum force of 5 N whichever comes first. Testing shell be canted out for 100 000 cycles.
During this test, no component shall rupture or break.
4.10 BehavIour under MR Imaging conditions
For each of the components used for the shunt, the manufacturer shall state if it is MR unsafe. MR safe or MR
compatdle in accordance with ASTM F2503-05.
4.11 Bursting pressure
Each component of the shunt shall be capable of withstanding a positive pressure of 19,6133 kPa (2 m of water column) inside the component without a significant change of its characteristics within a tolerance of ± 10 % of each specification. The charactertstics shall be in the described range at the latest, two hours after the pessure has been applied
5 SpecifIc requirements for components
5.1.1 Reflux performance of shunts conn.cting the ventricl, to the blood system
A maxiium 110w of 0,04 mI/mm is allowed to be dramed back in a pressure range between 0 and . iFe
(0 and 500 mm of water column) against the flow direction.
5.1.2 Long term stability
The long term stability of a valve shall be demonstrated according to the following test method:
— immerse the valve in distilled, degassed water,
keep the water temperature at blood temperature ± 5 C;
pump distilled, degassed water at an average flow rate of 20 mllh through the valve for 28 d.
During testing time, the charactenstics of the valve (e.g. flow rate or opening pressure) shall remain in the
range which Is slated in the instructions for use.
5.1.3 Influence of the changed posture of the patient on the valve performance
The manufacturer shall slate in the instructions for use if the characteristics of the valve depend on the posture of the patient.
If the characteristics depend on the posture, the compliance ci these characteristics with the values stated by the manufacturer shall be stated for honzontal and vertical position of the patient (see 4.6).
5.2 ResIstance of tubing and components
In addition to the pressure flow graph of the valve, the manufacturer shall describe the influence of tubing or other additional components in the accompanying documents.
NOTE Ths can be done by an additional pressure-flow diagram
6 Marking and labelling of shunts
The requirements of Iso 14630:2005 11.2, 11.5 and the following shall apply.
– – Information on how the opening pressure was measured shall be stated in the accompanying documentation.
The characteristic pressure depending performance shall be olven at a flow rate of 20 ml/h.