Eine linear-proportional regelbare Dauerinfusionspumpe zur stetig abstufbaren Applikation von Pharmaka

Summary

An improved pump for the continuous addition of drugs to the blood flowing through organs or to the fluid of perfusion systems is described; it has the following characteristics:

• 1. The adjustment of the infusion rate is stepless and linear-proportional. Thus, an adaptation to different flow rates of the perfusion is possible; the desired local end-concentration of the infused drug can be kept constant when rates of perfusion are variable. The pump speed further can be converted to be proportional to an external voltage e.g. that of an electromagnetic flowmeter or a perfusing roller pump or inversely proportional to the voltage of an electromanometer.

• 2. The system can be adapted to the use of different syringes of up to 50 ml. By an electrical adjustment the setting of the precision potentiometer for maximum pump speed represents an even number of millilitres; fractions thereof can be calculated easily.

• 3. A limit switch protects motor and gear against damage; furthermore, a variably adjustable release of a warning buzzer indicates that the syringe soon must be changed.

• 4. The syringe and its piston are firmly fixed. This is necessary in order to prevent jerks in the movement of the piston. Moreover, because of the fixation the direction of action can be reversed: fluid can be either infused or withdrawn.

• 5. Because of its small dimensions (case: 21×14×13 cm) the pump can be placed close to the perfusion equipment.

Possible applications of the pump are discussed, especially the intraarterial addition of drugs in perfusion experiments with constant flow or constant pressure.