Occlusion detection techniques for a fluid infusion device having a rotary pump mechanism and rotor position sensors
First Claim
1. A fluid pump mechanism comprising:
- a stator comprising a stator cam element having a stator cam surface;
a rotor comprising a reference surface and a rotor cam element having a variable height rising from the reference surface, the rotor cam element cooperating with the stator cam element to axially displace the rotor, relative to the stator, as a function of angular position of the rotor;
a biasing element that provides a biasing force to urge the rotor cam element toward the stator cam element and toward the reference surface; and
a detection circuit to process axial position data and angular position data of the rotor, and to determine that an upstream occlusion has occurred based on detectable characteristics of the axial and angular position data, wherein the detection circuit calculates axial velocity of the rotor, based on the axial position data, during a fluid expulsion period of the fluid pump mechanism, the fluid expulsion period indicated by the angular position data, and wherein the detection circuit determines that an upstream occlusion has occurred when the calculated axial velocity of the rotor exceeds a threshold axial velocity value.
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Accused Products
Abstract
An embodiment of a fluid infusion device includes a fluid pump mechanism having a rotor and a stator. The rotor includes a reference surface and a cam element rising from the reference surface, and the stator includes a cam element having a stator cam surface. The cam elements cooperate to axially displace the rotor as a function of angular position of the rotor. A biasing element provides force to urge the cam elements together. A drive motor actuates the rotor to pump medication fluid from a fluid cartridge module to a body, via a subcutaneous conduit. A detection circuit processes axial and angular position data of the rotor, and determines that an upstream occlusion has occurred based on detectable characteristics of the axial and angular position data.
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Citations
13 Claims
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1. A fluid pump mechanism comprising:
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a stator comprising a stator cam element having a stator cam surface; a rotor comprising a reference surface and a rotor cam element having a variable height rising from the reference surface, the rotor cam element cooperating with the stator cam element to axially displace the rotor, relative to the stator, as a function of angular position of the rotor; a biasing element that provides a biasing force to urge the rotor cam element toward the stator cam element and toward the reference surface; and a detection circuit to process axial position data and angular position data of the rotor, and to determine that an upstream occlusion has occurred based on detectable characteristics of the axial and angular position data, wherein the detection circuit calculates axial velocity of the rotor, based on the axial position data, during a fluid expulsion period of the fluid pump mechanism, the fluid expulsion period indicated by the angular position data, and wherein the detection circuit determines that an upstream occlusion has occurred when the calculated axial velocity of the rotor exceeds a threshold axial velocity value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A fluid infusion device for delivering a medication fluid to a body, the fluid infusion device comprising:
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a fluid pump mechanism that cooperates with a fluid cartridge module, the fluid pump mechanism comprising a rotor and a stator, the rotor comprising a reference surface and a rotor cam element having a variable height rising from the reference surface, the stator comprising a stator cam element having a stator cam surface, the rotor cam element cooperating with the stator cam element to axially displace the rotor, relative to the stator, as a function of angular position of the rotor; a biasing element that provides a biasing force to urge the rotor cam element toward the stator cam element and toward the reference surface; a subcutaneous conduit in fluid communication with an outlet valve of the fluid pump mechanism; a drive motor coupled to actuate the rotor of the fluid pump mechanism to pump medication fluid from the fluid cartridge module to the body, via the subcutaneous conduit; an axial position sensor to obtain axial position data of the rotor during operation of the fluid pump mechanism; an angular position sensor to obtain angular position data of the rotor during operation of the fluid pump mechanism; and a detection circuit to process the axial and angular position data of the rotor, and to determine that an upstream occlusion has occurred based on detectable characteristics of the axial and angular position data, wherein the detection circuit calculates axial velocity of the rotor, based on the axial position data, during a fluid expulsion period of the fluid pump mechanism, the fluid expulsion period indicated by the angular position data, and wherein the detection circuit determines that an upstream occlusion has occurred when the calculated axial velocity of the rotor exceeds a threshold axial velocity value. - View Dependent Claims (9, 10, 11, 12, 13)
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Specification