Fixed volume infusion device
First Claim
1. For use with a gravitational intravenous fluid system of the type in which intravenous fluid from an elevated source flows by gravity through tubing defining a flow passage under a pressure gradient to a vascular system of a patient, said pressure gradient being a higher static pressure of said intravenous fluid source in relation to a lower pressure of said patient vascular system, a fixed volume metering valve for providing incremental flow of said intravenous fluid comprising a housing bounding a chamber for a piston having an inlet at an upper end thereof in communication with said intravenous fluid source and at a lower opposite end an outlet in communication with said patient vascular system, an inverted U-shaped piston having three legs cooperating to bound therebetween a compartment and operatively disposed for opposite direction sliding movement in said chamber between an upper position of movement established by a horizontally oriented leg of said piston being adJacent said inlet and a lower position of movement established by the vertically oriented other two legs thereof being adJacent said outlet, a piston return spring disposed in said piston compartment so as to bias said piston in ascending movement from said lower to said upper position of movement, said ascending piston movement being normally prevented by said pressure gradient urging said piston in descending movement from said upper to said lower position of movement, and a normally open clamp operatively arranged to cyclically clamp closed said tubing so as to remove said pressure gradient from said flow system, whereby in response to said open condition of said clamp, said pressure gradient urges said piston in descending movement causing the dispensing of a selected fixed volume of intravenous fluid by said piston and in response to said closed clamp condition, said spring urges said piston in ascending movement, incident to repeating the fluid dispensing functioning thereof to thereby enable said metering valve to provide successive incremental intravenous fluid flow in selected fixed amounts through said gravitational intravenous fluid system.
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Accused Products
Abstract
In a gravity feed intravenous fluid delivery system, a fixed volume metering valve having an upwardly spring biased fluid-measuring piston that is also downwardly pressure biased and is effective to cause the dispensing of a fixed volume of intravenous fluid for each up and down cycle of piston movement, characterized by a cyclically operated clamp on the delivery tube of the system which, when the clamp is closed, allows the spring bias to lift the piston in ascending movement and, when in an open clamp condition, causes the pressure to urge the piston in descending movement, to thereby produce said up and down piston movement which cyclically dispenses the fixed volume of intravenous fluid.
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Citations
16 Claims
- 1. For use with a gravitational intravenous fluid system of the type in which intravenous fluid from an elevated source flows by gravity through tubing defining a flow passage under a pressure gradient to a vascular system of a patient, said pressure gradient being a higher static pressure of said intravenous fluid source in relation to a lower pressure of said patient vascular system, a fixed volume metering valve for providing incremental flow of said intravenous fluid comprising a housing bounding a chamber for a piston having an inlet at an upper end thereof in communication with said intravenous fluid source and at a lower opposite end an outlet in communication with said patient vascular system, an inverted U-shaped piston having three legs cooperating to bound therebetween a compartment and operatively disposed for opposite direction sliding movement in said chamber between an upper position of movement established by a horizontally oriented leg of said piston being adJacent said inlet and a lower position of movement established by the vertically oriented other two legs thereof being adJacent said outlet, a piston return spring disposed in said piston compartment so as to bias said piston in ascending movement from said lower to said upper position of movement, said ascending piston movement being normally prevented by said pressure gradient urging said piston in descending movement from said upper to said lower position of movement, and a normally open clamp operatively arranged to cyclically clamp closed said tubing so as to remove said pressure gradient from said flow system, whereby in response to said open condition of said clamp, said pressure gradient urges said piston in descending movement causing the dispensing of a selected fixed volume of intravenous fluid by said piston and in response to said closed clamp condition, said spring urges said piston in ascending movement, incident to repeating the fluid dispensing functioning thereof to thereby enable said metering valve to provide successive incremental intravenous fluid flow in selected fixed amounts through said gravitational intravenous fluid system.
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4. A control system for operating a fluid dispensing unit having a piston movable within a housing from a ready position to a home position to pass a measured volume of fluid through the unit, comprising:
- a timer adapted to generate a series of timing signals, said signals defining the dispensing rate of the unit;
pulse generating means operatively connected to said timer for generating a drive signal of predetermined length in response to receipt of a timing signal;
valve means operatively connected to said pulse generating means for passing fluid to said piston housing during the duration of said drive signal;
ready and home position sensors mounted to said housing for sensing the ready and home positions, respectively, of said piston and generating an output responsive thereto; and
alarm means operatively connected to said pulse generating means and ready and home sensors to generate an alarm signal when a combination of drive signal, ready sensor output and home sensor output indicates an improper operating condition. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
- a timer adapted to generate a series of timing signals, said signals defining the dispensing rate of the unit;
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15. A control system for operating a fluid dispensing unit having a piston movable within a housing from a ready position to a home position to pass a measured volume of fluid through the unit, comprising:
- a timer adapted to generate a series of timing signals, said signals defining the dispensing rate of the unit;
pulse generating means operatively connected to said timer for generating a drive signal of predetermined length in response to receipt of a timing signal;
valve means operatively connected to said pulse generating means for passing fluid to said piston housing during the duration of said drive signal;
ready and home position sensors mounted to said housing for sensing the ready and home positions, respectively, of said piston and generating an output responsive thereto;
an occlusion alarm operatively connected to said pulse generating means and home sensor for generating an occlusion alarm signal if the end of said drive signal occurs prior to receipt of said home signal;
a piston failure alarm operatively connected to said signal generating means and said home sensor for generating an air alarm signal when the time between receipt of said home signal and said ready signal exceeds a predetermined value.
- a timer adapted to generate a series of timing signals, said signals defining the dispensing rate of the unit;
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16. A fixed volume metering valve for providing incremental flow of intravenous fluid to a patient through a tubing connected between a source of said intravenous fluid and said patient comprising a housing bounding a chamber for a piston having an inlet at one end thereof in communication with said intravenous fluid source and at an opposite end an outlet in communication with said patient vascular system, an inverted U-shaped piston having three legs cooperating to bound therebetween a compartment and operatively disposed for opposite direction sliding movement in said chamber between a first position of movement established by a horizontally oriented leg of said piston being adjacent said inlet and a second position of movement established by the vertically oriented other two legs thereof being adjacent said outlet, a piston return spring disposed in said piston compartment so as to bias said piston in directional movement from said second to said first position of movement, said directional piston movement being normally prevented by a pressure gradient urging said piston in opposite directional movement from said first to said second position of movement, and a normally open clamp operatively arranged to cyclically clamp closed said tubing so as to remove said pressure gradient, whereby in response to said open condition of said clamp said pressure gradient urges said piston in said directional movement causing the dispensing of a selected fixed volume of intravenous fluid by said piston and in response to said closed clamp condition said spring urges said piston in said opposite directional movement incident to repeating the fluid dispensing functioning thereof to thereby enable said metering valve to provide successive incremental intravenous fluid flow in selected fixed amounts to said patient.
Specification
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- Resources
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Current AssigneeAndrew I. Sealfon
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Original AssigneeAndrew I. Sealfon
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InventorsSealfon, Andrew I.
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Primary Examiner(s)Yasko, John D.
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Application NumberUS07/274,327Time in Patent Office526 DaysField of Search604/65, 604/66, 604/67, 604/121, 604/122, 604/123, 604/151, 604/152, 604/153US Class Current604/65CPC Class CodesA61M 5/16809 by repeated filling and emp...G01F 11/021 of the piston type G01F11/0...G01F 11/029 provided with electric cont...
