Fluid flow control system
First Claim
1. In a system for parenteral administration of liquids at desired flow rates through a feeding tube from a liquid source to a patient, the combination comprising:
- syringe means for performing alternate fill and pump strokes to control the flow of liquid through the feeding tube;
motor means for driving said syringe means;
electrical pulsing means for providing output pulses to said motor means at a fill frequency and at a pump frequency to operate said syringe means; and
digital means for automatically varying said pump frequency output pulses as a function of said fill frequency output pulses to achieve the desired flow rate.
2 Assignments
0 Petitions
Accused Products
Abstract
A syringe pump operated by a stepping motor to repetitively fill and empty a syringe cartridge over a plurality of operational cycles of successive fill stroke and pump stroke periods. The motor is driven by drive pulses from a digital pulse generation and control system, the pulse frequency establishing a predetermined fixed rate of fill during the fill stroke and being preselected, in accordance with desired output flow rate, to establish the rate at which the syringe is emptied during the pump stroke. The drive pulse rate during a fill stroke exceeds the maximum pulse rate during a pump stroke and, in order to maintain a proportional relationship between the preselected pumping rate and the actual pumping rate over each complete cycle of successive fill and pump strokes, the drive pulse frequency during each pump stroke is automatically increased to compensate for the time lost during each fill stroke. This is accomplished by accelerating counting up of the electrical network defining each individual pump stroke drive pulse period for a time interval equal to a single fill stroke drive pulse period. A start-up subsystem insures proper cartridge installation prior to initiation of a pumping cycle. Appropriate alarms respond to improper operating conditions including leakage from the source during the pump stroke, empty bottle or insufficient flow during fill, air in the I.V. line, a stalled motor, lack of flow due to system component failure, or occurrence of a runaway high pumping rate.
161 Citations
59 Claims
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1. In a system for parenteral administration of liquids at desired flow rates through a feeding tube from a liquid source to a patient, the combination comprising:
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syringe means for performing alternate fill and pump strokes to control the flow of liquid through the feeding tube; motor means for driving said syringe means; electrical pulsing means for providing output pulses to said motor means at a fill frequency and at a pump frequency to operate said syringe means; and digital means for automatically varying said pump frequency output pulses as a function of said fill frequency output pulses to achieve the desired flow rate. - View Dependent Claims (2, 3, 4, 5, 6)
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7. In a system for parenteral administration of liquids via a syringe pump, apparatus comprising:
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motor means for driving a syringe through successive fill and pump strokes during which the syringe is first filled with liquid and the liquid is subsequently delivered from the syringe; electrical pulsing means for providing output pulses at a fill frequency and at a pump frequency to operate said motor means in said fill stroke and said pump stroke, respectively; and electrical control means for automatically varying the pump frequency of said output pulses during said pump stroke, to compensate for time lost during said fill stroke and to achieve the desired flow rate. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. In a syringe pump including a syringe, apparatus comprising:
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driving means for driving the syringe through a fill stroke in which the syringe is filled with fluid through an intake line and through a pump stroke during which fluid is delivered from the syringe through an output line; detection means responsive to fluid flow below a prescribed drop flow rate through the intake line during said fill stroke; and means for delaying the response to said prescribed drop flow rate for a pre-established period of time at the beginning of each fill stroke. - View Dependent Claims (28)
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29. In a syringe pump including a syringe, apparatus comprising:
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driving means for driving the syringe through a fill stroke in which the syringe is filled with fluid through an intake line and through a pump stroke during which fluid is delivered from the syringe through an output line; and detection means responsive to detection of fluid flow in said intake line during a pump stroke. - View Dependent Claims (30, 31, 32)
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33. In a syringe pump, apparatus comprising:
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motor means for driving the syringe through a fill stroke in which the syringe is filled with fluid through an input line and through a pump stroke during which fluid is delivered from the syringe through an output line; and detection means responsive to lack of a prescribed number of accumulated drops detected in said input line at the end of a fill stroke. - View Dependent Claims (34, 35)
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36. In a syringe pump for delivering fluid at selected flow rates, apparatus comprising:
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motor means for driving the syringe through a fill stroke in which the syringe is filled with fluid through an input line and through a pump stroke during which fluid is delivered from the syringe through an output line; means for generating motor drive pulses to energize said motor means; and detection means responsive to a high rate of said motor drive pulses in the absence of concurrent high flow rate selected. - View Dependent Claims (37)
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38. In a syringe pump including a syringe, apparatus comprising:
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means for driving the syringe through a fill stroke in which the syringe is filled with fluid through an intake line and through a pump stroke during which fluid is delivered from the syringe through an output line; and detection means responsive to fluid flow below a prescribed drop flow rate through the intake line during said fill stroke. - View Dependent Claims (39)
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40. In a syringe pump including a syringe, apparatus comprising:
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means for driving the syringe through a fill stroke in which the syringe is filled with fluid through an intake line and through a pump stroke during which fluid is delivered from the syringe through an output line; drop detection means responsive to drop flow in the intake line; and drop rate discriminator means, responsive to said drop detection means, for sensing fluid flow below a prescribed drop flow rate through the intake line during said fill stroke.
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41. In a syringe pump including a syringe, apparatus comprising:
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stepping motor means for driving the syringe through a fill stroke in which the syringe is filled with fluid through an input line and through a pump stroke during which fluid is delivered from the syringe through an output line at a selected fluid flow rate; means for generating motor drive pulses to energize said motor means; and compensation means for compensating all of said motor drive pulses during said pump stroke for the total time lost during performance of said fill stroke. - View Dependent Claims (42)
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43. in a syringe pump, the combination comprising:
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a syringe actuator; a stepping motor for driving said actuator; means for detecting the presence of a syringe; means responsive to the lack of presence of a syringe for energizing said stepping motor at a prescribed rate to drive said actuator; and means for sensing a predetermined position of said actuator for de-energizing said stepping motor, whereby a syringe may be installed.
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44. In a fluid pumping system for driving a disposable syringe having inlet and outlet ports and a piston slidably received within said syringe, the combination comprising:
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means for selecting a desired output fluid flow rate from said syringe; drive means for reciprocating said syringe piston, said drive means including a d.c. stepping motor; means for generating motor drive pulses during a fill stroke; means for generating motor drive pulses during a pump stroke; and means for compensating the frequency of all of the motor drive pulses during said pump stroke for time lost during said fill stroke.
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45. In a syringe pump, apparatus comprising:
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motor means for driving the syringe through a fill stroke in which the syringe is filled with fluid through an input line and through a pump stroke during which fluid is delivered from the syringe through an output line; rate multiplier means; means for deriving from said rate multiplier means a pump frequency proportional to desired fluid flow rate; and means for deriving a fixed fill frequency from said rate multiplier means, said fill frequency being in excess of the maximum value of said pump frequency. - View Dependent Claims (46)
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47. In a fluid pumping system for driving a syringe having inlet and outlet ports and a piston slidably received within said syringe, the combination comprising:
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means for selecting a desired output fluid flow rate from said syringe; drive means for reciprocating said syringe piston through a fill stroke, in which said syringe is filled with fluid through an input line and said inlet port, and through a pump stroke during which fluid is delivered through said outlet port and an output line, said drive means including a d.c. stepping motor; means for generating motor drive pulses during a fill stroke; means for generating motor drive pulses during a pump stroke; counting means for determining the duration of the period between successive pump stroke motor drive pulses; and means for counting up said period between successive pump stroke motor drive pulses, at twice the rate called for by the selected fluid flow rate, for a time interval equal to the period between successive fill stroke motor drive pulses, whereby the frequency of the motor drive pulses during said pump stroke is uniformly compensated for time lost during said fill stroke. - View Dependent Claims (48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58)
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59. In a fluid pumping system for driving a disposable syringe having inlet and outlet ports and a piston slidably received within said syringe, the combination comprising:
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rate multiplier means having a plurality of rate multiplier decades; variable rate selector switch means connected to said rate multiplier means for establishing a desired output fluid flow rate pump frequency from said rate multiplier means proportional to desired fluid flow rate from said syringe during a pump stroke in which fluid is delivered from said syringe through said outlet port and an outlet line; means for deriving a fixed fill frequency from said rate multiplier means proportional to a specified flow rate during a fill stroke in which said syringe is filled with fluid through said inlet port and an input line, said fill frequency being in excess of the maximum pump frequency; means for generating motor drive pulses at said fixed fill frequency during a fill stroke; means for generating motor drive pulses at a pump frequency during a pump stroke; counting means for counting up the period between successive pump stroke motor drive pulses; means for counting up said period between successive pump stroke motor drive pulses, at twice the normal rate called for by the selected fluid flow rate during the pump stroke, for a time interval equal to the period between successive fill stroke motor drive pulses, whereby the frequency of the motor drive pulses to said d.c. stepping motor is compensated during said pump stroke for time lost during said fill stroke; and means responsive to said counting means for resetting the high order rate multiplier decades at the beginning of each motor drive pulse period in the pump stroke.
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Specification