Positive control intravenous fluid administration

Claim 2

In the delivery of fluids parenterally by using an intravenous device which includes a drop former and a fluid conduit connected to the drop former for delivery of fluid from the drop former to a fluid delivery means, the method of controlling the volumetric flow through the fluid conduit comprising the steps of periodically opening the fluid conduit at a frequency equal to a desired rate of drop flow, detecting each drop formed in response to the opening of the fluid conduit, closing the fluid conduit each time a drop is formed and detected, determining the size of formed drops, and varying the time of subsequent openings of the fluid conduit by times relates directly responsive to the size of the formed drops whereby a desired volumetric rate is maintained.

Claim 3

The method of claim 1 further comprising the step of giving an alarm whenever a drop is not detected within a given period of time less than the drop period after the opening of the fluid conduit.

Claim 4

The method of claim 1 further comprising the steps of monitoring the state of the conduit and giving an alarm whenever the open or closed state of the conduit is different from the desired state of the conduit.

Claim 5

In a system for delivery of fluids by means of a flow of drops, apparatus for controlling the rate of flow of the drops comprising, drop forming means for forming drops of the fluid, a fluid conduit having one end connected to said drop forming means for receiving fluid therefrom and another end for delivery of fluid, an electromechanical clamping means on said conduit, said clamping means being in a normally closed position but shifting to an open position in response to the receipt of a signal of a given level, a bistable signal generator means having input means for receiving control signals and output means connected to said electromechanical clamping means for transmitting a signal having other than the given level when in a first state and for transmitting a signal having the given level when in a second state, said input means having means for switching said bistable signal generator means to said first state upon receipt of a first control signal and for switching said bistable signal generator means to said second state upon receipt of a second control signal, source means connected to said input means for periodically generating said first control signals with a repetition rate equal to a desired drop delivery rate, drop detector means for generating one of said second control signals each time a drop is formed and delivered by said drop forming means, indicating means for giving an indication of the size of the drops detected by said drop detector means, and means for controlling the frequency of the generation of said first control signals in accordance with the indications given by said indicating means.

Claim 6

In a system for delivery of fluids by means of a flow of drops, apparatus for controlling the rate of flow of the drops comprising, drop forming means for forming drops of the fluid, a fluid conduit having one end connected to said drop forming means for receiving fluid therefrom and another end for delivery of fluid, an electromechanical clamping means on said conduit, said clamping means being in a normally closed position but shifting to an open position in response to the receipt of a signal of a given level, a bistable signal generator means having input means for receiving control signals and output means connected to said electromechanical clamping means for transmitting a signal having other than the given level when in a first state and for transmitting a signal having the given level when in a second state, said input means having means for switching said bistable signal generator means to said first state upon receipt of a first control signal and for switching said bistable signal generator means to said second state upon receipt of a second control signal, source means connected to said input means for periodically generating said first control signals with a repetition rate equal to a desired drop delivery rate, drop detector means for generating one of said second control signals each time a drop is formed and delivered by said drop forming means, indicating means for giving an indication of the size of the drops detected by said drop detector means, and means for controlling the frequency of the generation of said first control signals in accordance with the indications given by said indicating means.

Claim 7

The apparatus of claim 4, wherein said source means is a signal pulse generator having a controllably variable repetition rate.

Claim 8

The apparatus of claim 4 further comprising time measuring means for measuring the time between a first control signal and the next occurring second control signal, and means response to said time measuring means for giving an alarm when said time exceeds a given duration.

Claim 9

The apparatus of claim 4 wherein said drop detecting means comprises a funnel member operatively positioned in the path of travel of drops formed by said drop forming means, said funnel member having an output end, a pair of electrodes spaced from each other at said output end by a distance which is less than the minimum drop diameter, a pair of electrical conductors respectively connected to said electrodes and disposed along the outer wall of said funnel member, and circuit means for generating one of said second control signals whenever the electrodes are electrically connected by a drop of fluid passing through the output end of said funnel means.

Claim 10

The apparatus of claim 4 wherein the portion of the fluid conduit engaged by said clamping means has a pair of diametrically opposite axially entending sections where the tubing is fused.

Claim 11

The apparatus of claim 4 further comprising means for monitoring the position of said electromechanical clamping means, and means for giving an alarm whenever said electromechanical clamping means is in a closed position whenever a second control signal is generated.

Claim 12

The apparatus of claim 4 further comprising means for monitoring the position of said electromechanical clamping means, and means for giving an alarm whenever said electromechanical clamping means is in an open position whenever a first control signal is generated.

Claim 13

The apparatus of claim 10 further comprising auxiliary clamping means for clamping said fluid conduit closed whenever an alarm is given.

Claim 14

Apparatus for detecting the passage of drops of a conductive liquid along a given path comprising a funnel means of insulative material positioned in the path for intercepting the drops, said funnel means of insulative material having an output end, first and second electrodes spaced opposite each other and only at the output end of said funnel means, first and second electrical conductors respectively connected to said first and second electrodes and fixed to the outer wall of said funnel means, and circuit means connected to said electrical conductors for generating an electrical signal whenever a drop of conductive fluid bridges said electrodes, said circuit means also including means for determining the size of said drops.

Claim 15

Apparatus for detecting the passage of drops of a conductive liquid along a given path comprising a funnel means of insulative material positioned in the path for intercepting the drops, said funnel means of insulative material having an output end, first and second electrodes spaced opposite each other and only at the output end of said funnel means, first and second electrical conductors respectively connected to said first and second electrodes and fixed to the outer wall of said funnel means, and circuit means connected to said electrical conductors for generating an electrical signal whenever a drop of conductive fluid bridges said electrodes, said circuit means also including means for determining the size of said drops.

Claim 16

The apparatus of claim 12 wherein the output end of said funnel means is an opening having a circular periphery and each of said electrodes is an arcuate member disposed on said circular periphery.

Claim 17

The apparatus of claim 13 wherein each of said electrodes extends in the order of 90° around the circular periphery.

Claim 18

The apparatus of claim 12 wherein said funnel means is provided with venting openings.