Dosing device for the volumetric dosing of a liquid additive
First Claim
1. A dosing device for volumetric dosing of a liquid additive which is added in a certain volume ratio to a fluid flowing in two hose lines comprising a first hose line and a second hose line which feeds directly or indirectly into the first hose line, said dosing device comprising two electrically triggerable valve means which are each inserted into one of two hose lines and coupled so that only one of the two valve means is switched in a switching cycle to an open position;
- a counting and control unit (CPU, RAM);
a drip tube which extends downstream from a junction;
a drip chamber connecting downstream from the drip tube; and
a light barrier, the direction of action of which is arranged transversely to a fall path of drops of additive, whereby drops falling in the drip chamber are counted and the valve means is alternately triggered by the counting and control unit after a certain number of drops have been counted.
1 Assignment
0 Petitions
Accused Products
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device for volumetric dosing of a liquid additive which is added in a certain volume ratio to a fluid, in particular withdrawn blood, flowing in a first hose line, via a second hose line feeding directly or indirectly into the first hose line.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 result of capillary action thereby brings about a volume constancy between drops falling at the lower end of the drip tube and additive which is added at the upper end of the drip tube.
-
Citations
11 Claims
-
1. A dosing device for volumetric dosing of a liquid additive which is added in a certain volume ratio to a fluid flowing in two hose lines comprising a first hose line and a second hose line which feeds directly or indirectly into the first hose line, said dosing device comprising two electrically triggerable valve means which are each inserted into one of two hose lines and coupled so that only one of the two valve means is switched in a switching cycle to an open position;
- a counting and control unit (CPU, RAM);
a drip tube which extends downstream from a junction;
a drip chamber connecting downstream from the drip tube; and
a light barrier, the direction of action of which is arranged transversely to a fall path of drops of additive, whereby drops falling in the drip chamber are counted and the valve means is alternately triggered by the counting and control unit after a certain number of drops have been counted. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
- a counting and control unit (CPU, RAM);
Specification