Intravenous-line flow-control system
First Claim
1. An intravenous-line flow-control system for receiving a disposable cassette disposed in the intravenous line and preventing the free flow of intravenous fluid through the cassette as the cassette is removed from the system, the system comprising:
- a housing having a receiving surface against which the cassette is placed;
door means, connected to the housing, for holding the cassette against the receiving surface when the door means is closed and for allowing removal of the cassette when the door means is open;
door-opening means for causing, upon actuation by a user, the opening of the door means;
turning means for turning a rotatable control valve on the cassette in order to restrict variably the flow of fluid through the cassette, the turning means including a stepper motor and a transmission member, capable of being turned by the stepper motor and capable, when the door means is closed, of engaging the control valve to transmit torque from the motor to the control valve, the transmission member being movably mounted in the housing;
motor-disengagement means, connected to the door-opening means, for moving, when the door-opening means is being actuated but while the cassette is still held against the receiving surface, at least the transmission member of the turning means with respect to the housing from a first position to a second position away from the cassette'"'"'s control valve so that the transmission member becomes disengaged from the control valve; and
shut-off means, connected to the door-opening means, for engaging, when the door-opening means is being actuated but while the cassette is still held against the receiving surface, the cassette'"'"'s control valve and turning the control valve to its closed position.
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Accused Products
Abstract
An intravenous-line flow-control system for receiving a disposable cassette disposed in the intravenous line. The system prevents the free flow of intravenous fluid through the cassette when the cassette is removed from the system. The system includes a control unit having a door or similar structure for holding the cassette against a receiving surface. The control unit includes a stepper motor and a transmission member for turning a rotatable control valve on the cassette in order to restrict variably the flow of fluid through the cassette. When the door is being opened but while the cassette is still held against the receiving surface, a motor-disengagement mechanism moves at least the transmission member, and preferably the stepper motor as well, from a first position, from which the control valve may be engaged by the transmission member, to a second position, in which the transmission member is disengaged from the control valve. Preferably, the motor-disengagement mechanism includes a button on the handle of a door-opening mechanism, and by pushing the button the transmission member and the stepper motor are moved to the second position. In addition, when the door is being opened but while the cassette is still held against the receiving surface, a shut-off mechanism engages the cassette'"'"'s control valve and turns the control valve to its closed position. The control unit may use alternative power supplies and include links for communicating with other control units.
201 Citations
12 Claims
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1. An intravenous-line flow-control system for receiving a disposable cassette disposed in the intravenous line and preventing the free flow of intravenous fluid through the cassette as the cassette is removed from the system, the system comprising:
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a housing having a receiving surface against which the cassette is placed; door means, connected to the housing, for holding the cassette against the receiving surface when the door means is closed and for allowing removal of the cassette when the door means is open; door-opening means for causing, upon actuation by a user, the opening of the door means; turning means for turning a rotatable control valve on the cassette in order to restrict variably the flow of fluid through the cassette, the turning means including a stepper motor and a transmission member, capable of being turned by the stepper motor and capable, when the door means is closed, of engaging the control valve to transmit torque from the motor to the control valve, the transmission member being movably mounted in the housing; motor-disengagement means, connected to the door-opening means, for moving, when the door-opening means is being actuated but while the cassette is still held against the receiving surface, at least the transmission member of the turning means with respect to the housing from a first position to a second position away from the cassette'"'"'s control valve so that the transmission member becomes disengaged from the control valve; and shut-off means, connected to the door-opening means, for engaging, when the door-opening means is being actuated but while the cassette is still held against the receiving surface, the cassette'"'"'s control valve and turning the control valve to its closed position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for controlling flow through an intravenous-line having a cassette disposed therein, and preventing the free flow of intravenous fluid through the cassette as the cassette is removed from a control unit, the method comprising the steps of:
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providing on the cassette a rotatable valve with a control wheel having a circumference, wherein the control wheel has first and second engaging means, the first engaging means including a plurality of teeth closely located with respect to each other and evenly distributed around the circumference of the control wheel, except for a sector of the circumference that lacks teeth; providing a stepper motor in the control unit for controlling the setting of the control wheel, by engaging the control wheel'"'"'s second engaging means, in order to restrict variably the flow of intravenous fluid through the cassette; providing a motor-disengagement mechanism in the control unit for disengaging the stepper motor from the control wheel'"'"'s second engaging means; and providing a shut-off mechanism in the control unit for turning the control wheel to close the valve, after the stepper motor is disengaged from the control wheel'"'"'s second engaging means but before the cassette can be removed the shut-off mechanism having a gear for engaging the control wheel'"'"'s first engaging means; wherein the sector of the control wheel'"'"'s circumference that lacks teeth is located so that, when the valve is in its fully closed position, the sector lacking teeth is adjacent the shut-off mechanism'"'"'s gear, so that the shut-off mechanism does not continue turning the control wheel after the valve is fully closed.
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12. A system for controlling flow through an intravenous-line, and preventing the free flow of intravenous fluid through the line cassette as the line is removed from the system, the system comprising:
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a cassette having a rotatable valve with a control wheel having a circumference, wherein the control wheel has first and second engaging means, the first engaging means including a plurality of teeth closely located with respect to each other and evenly distributed around the circumference of the control wheel, except for a sector of the circumference that lacks teeth; a control unit; turning means, in the control unit, for controlling the setting of the control wheel, by engaging the control wheel'"'"'s second engaging means, in order to restrict variably the flow of intravenous fluid through the cassette; motor-disengagement means, in the control unit, for causing the turning means to disengage the control wheel'"'"'s second engaging means; and shut-off means, in the control unit, for turning the control wheel to close the valve, after the turning means is disengaged from the control wheel'"'"'s second engaging means but before the cassette is removed from the control unit, the shut-off means having a gear for engaging the control wheel'"'"'s first engaging means; wherein the sector of the control wheel'"'"'s circumference that lacks teeth is located so that, when the valve is in its fully closed position, the sector lacking teeth is adjacent the shut-off means'"'"'s gear, so that the shut-off means does not continue turning the control wheel after the valve is fully closed.
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Specification