Positive control intravenous fluid administration
OwnerPatricia M. Sadlier, Edward Willettinventors
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Abstract
A method and apparatus for parenteral administration of medical fluids has a normally closed clamp on the intraveneous feeding tube which is opened by means of an electromagnetic actuator at a preselected drop frequency rate and closed when a drop is detected by a conductive path established by the drop passing between two opposing electrodes. The electrical system governing the drop counting electrodes also is provided with drop size measuring means which acts to control the preselected drop frequency rate wherein a desired volumetric rate is maintained. Safety features are also provided to prevent excessive or insufficient flow rates.
Claims15
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.
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.
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.
Dependencies are inferred from the claim text.