Apparatus for infusing liquids into human or animal bodies

An apparatus for infusing of a liquid into a human or animal body comprising a catheter for extending into a blood stream of the body, a supply reservoir for the liquid having a discharge conduit, pressure generator means for applying a pressure on the liquid in the supply reservoir to cause discharge through the discharge conduit, and an adjustable dosing means attached between the catheter and the discharge conduit for producing a desired infusion rate in the catheter, said pressure generator means being an over-pressure generator operating without an external energy source and constantly maintaining the liquid in the supply reservoir at an excess pressure as compared with the pressure prevailing at the point of the liquid discharge from the catheter, said adjustable dosing means including means for providing an infusion flow at a base rate and means including a controllable switching valve means for periodically producing an infusion flow at a peak value, said switching valve being operable by a switching pulse, a switch pulse transmitter means for producing the switching pulse with one of the repetition rates and duration of the switching pulses being programmatically predetermined for the purpose of producing a periodic release of the liquid at a peak rate from the supply reservoir through the catheter to the body at pre-programmed time intervals, said means for providing a flow rate at a base rate comprising a flow limiting device having a preselected flow cross section, said flow limiting device being connected between the discharge conduit and the catheter and parallel with the switching valve means so that the base rate is discharged regardless of actuation of the switching valve means.

An apparatus for infusing of liquid into a human or animal body comprising a catheter for extending into a blood stream of a body, a supply reservoir for the liquid having a discharge conduit, pressure generator means for applying a pressure on the liquid in the supply reservoir to cause discharge through the discharge conduit, and an adjustable dosing means attached between the catheter and the discharge conduit for producing a desired infusion rate in the catheter, said pressure generator means being an over-pressure generator operating without an external energy source and constantly maintaining the liquid in the supply reservoir at an excess pressure as compared with the pressure prevailing at the point of the liquid discharge from the catheter, said adjustable dosing means including means for providing an infusion flow at a base rate and means including a controllable switching valve means for periodically producing an infusion flow at a peak value, said switching valve means being operable by a switching pulse, a switch pulse transmitter means for producing the switching pulse with one of the repetition rates and duration of the switching pulses being programmatically predetermined for the purpose of producing a periodic release of the liquids from the supply reservoir through the catheter to the body at pre-programmed time intervals, said over-pressure generator including a sensor means for sensing a change in one of the temperature and pressure of the over-pressure generator, said sensor means being coupled to the switch pulse transmitter means to effect a change of liquid flow by adjusting the switch pulse duration in inverse proportion to the adjusting the switch pulse duration in inverse proportion to the change in pressure in the over-pressure generator.