Dosing device for the volumetric dosing of a liquid additive

US5512046A · kind A · utility

Assignee

• Fresenius AG · DE

Inventors

• Thomas Pusinelli · Schongau, DE
• Dieter Mushoff · Lich, DE

Key dates

• Filing date: Nov 17, 1994
• Grant date: Apr 30, 1996
• Expiry date: Nov 17, 2014

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61M5/16827
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A dosing device for volumetric dosing of a liquid additive which is added in a certain volume ratio to a fluid, in particular withdrawn blood, flowing in a first hose line, via a second hose line feeding directly or indirectly into the first hose line. The dosing device for the volumetric dosing of an anticoagulant fluid or a sedimentation accelerator is preferably provided in a system for the collection and retransfusion of autologous blood which has a hose or tube section which extends downstream from the junction, and also a drip chamber connecting downstream from the drip tube and a light barrier, the direction of action of which is arranged transversely to the fall path of the drops. In order to avoid incorrect dosing because of changing viscosities of the liquid flowing in the first hose line, and thus of changing drop sizes, two electrically-triggerable valve means, one of which is in each case inserted into one of the two hose lines, are provided. The valve means are triggered alternately by means of a counting and control unit in such a way that in each case only one of the two named hoses is switched to "open" at the same time. The liquid remaining in the drip tube as a r…