Occlusion detection techniques for a fluid infusion device having a rotary pump mechanism and multiple sensor contact elements

Patent metadata

Field	Value
Publication number	US-2016367754-A1
Application number	US-201514746654-A
Country	US
Kind code	A1
Filing date	Jun 22, 2015
Priority date	Jun 22, 2015
Publication date	Dec 22, 2016
Grant date	—

Abstract

A fluid infusion device includes a pump having a rotor and a stator. A rotor cam element rises from a reference surface of the rotor. The stator includes a cam element having a stator cam surface. The cam elements axially displace the rotor as the rotor revolves. Inlet and outlet valves open and close as a function of angular and axial position of the rotor. A motor actuates the rotor to pump fluid to a body, via a subcutaneous conduit. First and second contact elements are located on the rotor. A sensing element on the stator cooperates with a detection circuit to detect when the sensing element makes contact with the first sensor contact element and the second sensor contact element. The detection circuit monitors a detection signal obtained from the sensing element to determine an operating condition of the fluid pump mechanism.

First claim

What is claimed is:

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; an inlet valve that opens and closes as a function of angular and axial position of the rotor relative to the stator; an outlet valve that opens and closes as a function of angular and axial position of the rotor relative to the stator; a biasing element that provides a biasing force to urge the rotor toward the stator; a first sensor contact element on the rotor and located at an angular position that follows an upper edge of the rotor cam element; a second sensor contact element on the rotor and located at an angular position that follows the first sensor contact element; and a sensing element on the stator, the sensing element cooperating with a detection circuit to detect when the sensing element makes contact with the first sensor contact element and the second sensor contact element; wherein the detection circuit monitors characteristics of a detection signal obtained from the sensing element in response to angular position of the rotor to determine an operating condition of the fluid pump mechanism.

2 . The fluid pump mechanism of claim 1 , wherein the first and second sensor contact elements are located on the reference surface in a region that is unoccupied by the rotor cam element.

3 . The fluid pump mechanism of claim 1 , wherein:
the rotor comprises an endcap having a rim; the reference surface and the rotor cam element are located inside the endcap; and the first and second sensor contact elements are located on the rim.

4 . The fluid pump mechanism of claim 1 , wherein the sensing element comprises:
a first conductive spring tab electrically coupled to the detection circuit; and a second conductive spring tab electrically coupled to the detection circuit.

5 . The fluid pump mechanism of claim 1 , wherein:
angular positioning of the first sensor contact element on the rotor corresponds to a first valve state that occurs after the inlet valve closes for a current pumping cycle, and before the outlet valve opens for the current pumping cycle; and angular positioning of the second sensor contact element on the rotor corresponds to a second valve state that occurs after the outlet valve closes for the current pumping cycle, and before the inlet valve opens for a next pumping cycle.

6 . The fluid pump mechanism of claim 1 , wherein the detection circuit initiates an alert, alarm, or warning message in response to detecting a fault condition.

7 . The fluid pump mechanism of claim 6 , wherein the fault condition is a downstream occlusion or an upstream occlusion.

8 . The fluid pump mechanism of claim 1 , wherein, under normal operating conditions:
the sensing element makes no contact with the first sensor contact element; and the sensing element contacts the second sensor contact element once per pumping cycle.

9 . The fluid pump mechanism of claim 1 , wherein, under upstream occlusion conditions:
the sensing element contacts the first sensor contact element once per pumping cycle; the sensing element contacts the second sensor contact element once per pumping cycle; and the detection circuit determines that an upstream occlusion has occurred based on the sensing element contacting the first and second sensor contact elements.

10 . The fluid pump mechanism of claim 1 , wherein, under downstream occlusion conditions:
the sensing element makes no contact with the first sensor contact element; the sensing element makes no contact with the second sensor contact element; and the detection circuit determines that a downstream occlusion has occurred based on the sensing element making no contact with the first and second sensor contact elements.

11 . A fluid infusion device for delivering a medication fluid to a body, the fluid infusion device comprising:
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; an inlet valve that opens and closes as a function of angular and axial position of the rotor relative to the stator; an outlet valve that opens and closes as a function of angular and axial position of the rotor relative to the stator; a biasing element that provides a biasing force to urge the rotor toward the stator; a subcutaneous conduit in fluid communication with the outlet valve; 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; a first sensor contact element on the rotor and located at an angular position that follows an upper edge of the rotor cam element; a second sensor contact element on the rotor and located at an angular position that follows the first sensor contact element; and a sensing element on the stator, the sensing element cooperating with a detection circuit to detect when the sensing element makes contact with the first sensor contact element and the second sensor contact element; wherein the detection circuit monitors characteristics of a detection signal obtained from the sensing element in response to angular position of the rotor to determine an operating condition of the fluid pump mechanism.

12 . The fluid infusion device of claim 11 , wherein:
angular positioning of the first sensor contact element on the rotor corresponds to a first valve state that occurs after the inlet valve closes for a current pumping cycle, and before the outlet valve opens for the current pumping cycle; and angular positioning of the second sensor contact element on the rotor corresponds to a second valve state that occurs after the outlet valve closes for the current pumping cycle, and before the inlet valve opens for a next pumping cycle.

13 . The fluid infusion device of claim 12 , wherein, under normal operating conditions:
the sensing element makes no contact with the first sensor contact element; and the sensing element contacts the second sensor contact element once per pumping cycle.

14 . The fluid infusion device of claim 12 , wherein, under upstream occlusion conditions:
the sensing element contacts the first sensor contact element once per pumping cycle; the sensing element contacts the second sensor contact element once per pumping cycle; and the detection circuit determines that an upstream occlusion has occurred based on the sensing element contacting the first and second sensor contact elements.

15 . The fluid infusion device of claim 12 , wherein, under downstream occlusion conditions:
the sensing element makes no contact with the first sensor contact element; the sensing element makes no contact with the second sensor contact element; and the detection circuit determines that a downstream occlusion has occurred based on the sensing element making no contact with the first and second sensor contact elements.

16 . A fl

Assignees

• Medtronic Minimed Inc

Inventors

• Alderete Jr Juan M
• Yavorsky Matthew William
• Pananen Jacob E

Classifications

• F04B2201/02011

  Angular position of a piston rotating around its own axis · CPC title

• F04B2201/0201

  Position of the piston · CPC title

• F04B53/162

  Adaptations of cylinders · CPC title

• F04B49/065

  and making use of computers · CPC title

• F04B17/03

  driven by electric motors · CPC title