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Accessible Unlicensed Requires Authentication Published by De Gruyter July 29, 2015

An adjustable flow restrictor for implantable infusion pumps based on porous ceramics

Holger Jannsen, Stephan Klein and Bodo Nestler


This paper describes an adjustable flow restrictor for use in gas-driven implantable infusion pumps, which is based on the resistance of a flow through a porous ceramic material. The flow inside the walls of a ceramic tube can be adjusted between 270 nl/min and 1260 nl/min by changing the flow path length in the ceramic over a distance of 14 mm. The long-term stability of the flow restrictor has been analyzed. A drift of -8% from the nominal value was observed, which lies within the required tolerance of ±10% after 30 days. The average time needed to change the flow rate is 40 s. In addition, the maximum adjustment time was 110 s, which also lies within the specification.

Corresponding author: Bodo Nestler, Luebeck University of Applied Sciences, Medical Sensors and Devices Lab, Mönkhofer Weg 239, 23562 Lübeck, Germany, Phone: +49 451 300 5524, Fax: +49 451 300 5100, E-mail:


The authors would like to thank the German Federal Ministry for Education and Science for funding the project “VarioPump” within its program “Intelligente Implantate” (BMBF 16SV3784) and the company Tricumed Medizintechnik GmbH, Kiel, for the good cooperation.


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Received: 2015-4-15
Accepted: 2015-7-10
Published Online: 2015-7-29
Published in Print: 2015-8-1

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