Flow sensor for an infusion pump
First Claim
1. A medication infusion pump, comprising:
- a pump housing having a medication chamber formed therein for receiving a supply of a selected medication;
pump means within said housing for delivering the medication from said medication chamber through a discharge conduit to a patient; and
flow sensor means for monitoring flow of the medication through said discharge conduit, said flow sensor means including an inductor coil mounted externally about said discharge conduit, and a core pin of a magnetically attractable material mounted within said discharge conduit for displacement therein relative to said inductor coil in response to medication flow through said discharge conduit;
said flow sensor means including means for normally retaining said core pin in a first position retracted from said inductor coil during nonflow of medication through said discharge conduit, said core pin responding to flow of medication through said discharge conduit for displacement from said first position to a second position disposed generally coaxially within said inductor coil;
said core pin retaining means comprising means for magnetically retracting said core pin to said first position.
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0 Petitions
Accused Products
Abstract
An infusion pump for delivering a selected medication to a patient is provided with an inductance flow sensor for monitoring and verifying delivery of medication in response to pump operation. The flow sensor comprises a compact inductor coil wrapped about a pump discharge conduit, in combination with a magnetically attractable core pin disposed within the discharge conduit for movement to a position within the inductor coil in response to pump outflow. A control circuit operates with minimal power requirements to monitor coil inductance changes as a result of core pin displacement to confirm medication delivery to the patient in response to pump operation. A magnet mounted at one end of the inductor coil draws and retains the core pin at a position retracted from the coil in the absence of pump outflow.
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Citations
19 Claims
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1. A medication infusion pump, comprising:
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a pump housing having a medication chamber formed therein for receiving a supply of a selected medication; pump means within said housing for delivering the medication from said medication chamber through a discharge conduit to a patient; and flow sensor means for monitoring flow of the medication through said discharge conduit, said flow sensor means including an inductor coil mounted externally about said discharge conduit, and a core pin of a magnetically attractable material mounted within said discharge conduit for displacement therein relative to said inductor coil in response to medication flow through said discharge conduit; said flow sensor means including means for normally retaining said core pin in a first position retracted from said inductor coil during nonflow of medication through said discharge conduit, said core pin responding to flow of medication through said discharge conduit for displacement from said first position to a second position disposed generally coaxially within said inductor coil; said core pin retaining means comprising means for magnetically retracting said core pin to said first position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A flow sensor for monitoring and verifying actual flow of a medication from a medication dispensing pump through a pump discharge conduit for delivery to a patient, said flow sensor comprising:
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an inductor coil mounted about the pump discharge conduit; a core pin of a magnetically attractable material mounted along the pump discharge conduit; means forming first and second generally opposed end stops along the pump discharge conduit for limiting movement of said core pin along the conduit between a first position generally retracted from said inductor coil and a second position generally coaxially within said inductor coil; and retraction means for normally drawing and retaining said core pin at said first position, said core pin responding to medication flow through the pump discharge conduit for movement to said second position for the duration of said flow, said core pin cooperating with the pump discharge conduit to permit medication flow through the conduit and past the core pin; said retraction means comprising a magnet mounted along the pump discharge conduit at a position generally axially adjacent to said inductor coil. - View Dependent Claims (13, 14)
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15. An inductance flow sensor for monitoring and verifying fluid flow through a flow passage, said flow sensor comprising:
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a generally tubular member adapted for in-line connection with the flow passage for flow of the fluid therethrough; a core pin of a magnetically attractable material mounted within said tubular member for movement therein between a first position seated against a first end stop defined by said tubular member, and a second position spaced from said first end stop; an inductor coil mounted externally about said tubular member at a position with said core pin generally retracted axially therefrom when said core pin is in said first position, and with said core pin disposed generally coaxially therein when said core pin is in said second position; and retraction means for magnetically drawing and retaining said core pin in said first position during nonflow of the fluid through said tubular member, said core pin being displaced upon flow of the fluid through said tubular member to said second position, said core pin cooperating with said tubular member to permit fluid flow therethrough past said core pin when said core pin is spaced from said first end stop. - View Dependent Claims (16, 17, 18, 19)
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Specification