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

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 electrically conductive sensor contact element on the rotor and located at an angular position that follows an upper edge of the rotor cam element;
• a second electrically conductive sensor contact element on the rotor and located at an angular position that follows the first electrically conductive sensor contact element;
• and
• an electrically conductive sensing element on the stator, the electrically conductive sensing element cooperating with a detection circuit to detect when the electrically conductive sensing element makes physical and electrical contact with the first electrically conductive sensor contact element and the second electrically conductive sensor contact element;
• wherein the detection circuit monitors characteristics of a detection signal obtained from the electrically conductive sensing element in response to angular position of the rotor to determine an operating condition of the fluid pump mechanism;
• wherein, under normal operating conditions:
• the electrically conductive sensing element makes no physical or electrical contact with the first electrically conductive sensor contact element;
• and
• the electrically conductive sensing element physically and electrically contacts the second electrically conductive sensor contact element once per pumping cycle.

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 electrically conductive sensor contact element on the rotor and located at an angular position that follows an upper edge of the rotor cam element;
• a second electrically conductive sensor contact element on the rotor and located at an angular position that follows the first electrically conductive sensor contact element;
• and
• an electrically conductive sensing element on the stator, the electrically conductive sensing element cooperating with a detection circuit to detect when the electrically conductive sensing element makes physical and electrical contact with the first electrically conductive sensor contact element and the second electrically conductive sensor contact element;
• wherein the detection circuit monitors characteristics of a detection signal obtained from the electrically conductive sensing element in response to angular position of the rotor to determine an operating condition of the fluid pump mechanism;
• wherein, under upstream occlusion conditions:
• the electrically conductive sensing element physically and electrically contacts the first electrically conductive sensor contact element once per pumping cycle;
• the electrically conductive sensing element physically and electrically contacts the second electrically conductive sensor contact element once per pumping cycle;
• and
• the detection circuit determines that an upstream occlusion has occurred based on the electrically conductive sensing element physically and electrically contacting the first and second electrically conductive sensor contact elements.

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 electrically conductive sensor contact element on the rotor and located at an angular position that follows an upper edge of the rotor cam element;
• a second electrically conductive sensor contact element on the rotor and located at an angular position that follows the first electrically conductive sensor contact element;
• and
• an electrically conductive sensing element on the stator, the electrically conductive sensing element cooperating with a detection circuit to detect when the electrically conductive sensing element makes physical and electrical contact with the first electrically conductive sensor contact element and the second electrically conductive sensor contact element;
• wherein the detection circuit monitors characteristics of a detection signal obtained from the electrically conductive sensing element in response to angular position of the rotor to determine an operating condition of the fluid pump mechanism;
• wherein, under downstream occlusion conditions:
• the electrically conductive sensing element makes no physical or electrical contact with the first electrically conductive sensor contact element;
• the electrically conductive sensing element makes no physical or electrical contact with the second electrically conductive sensor contact element;
• and
• the detection circuit determines that a downstream occlusion has occurred based on the electrically conductive sensing element making no physical or electrical contact with the first and second electrically conductive sensor contact elements.

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 electrically conductive sensor contact element on the rotor and located at an angular position that follows an upper edge of the rotor cam element;
• a second electrically conductive sensor contact element on the rotor and located at an angular position that follows the first electrically conductive sensor contact element;
• and
• an electrically conductive sensing element on the stator, the electrically conductive sensing element cooperating with a detection circuit to detect when the electrically conductive sensing element makes physical and electrical contact with the first electrically conductive sensor contact element and the second electrically conductive sensor contact element;
• wherein the detection circuit monitors characteristics of a detection signal obtained from the electrically conductive sensing element in response to angular position of the rotor to determine an operating condition of the fluid pump mechanism;
• wherein angular positioning of the first electrically conductive 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
• wherein angular positioning of the second electrically conductive 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.