Occlusion detection techniques for a fluid infusion device having a rotary pump mechanism and an optical sensor

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 stator comprising a rotor chamber and a stator cam element having a stator cam surface, the rotor comprising an endcap and an axial extension section protruding from the endcap, the axial extension section shaped and sized for insertion into the rotor chamber of the stator;
• the rotor further comprising an optically detectable tab located around an outer exposed surface of the endcap, a reference surface, and a rotor cam element having a variable height rising from the reference surface, wherein the optically detectable tab rotates and axially translates as a function of angular position of the rotor;
• 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;
• wherein the rotor further comprises a conical tapered section having an asymmetrical profile, the conical tapered section located between the endcap and the axial extension section to remain exposed during operation of the fluid pump mechanism;
• 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;
• and
• an optical detection circuit to interrogate the outer exposed surface of the endcap to detect the optically detectable tab once per revolution of the rotor, and to interrogate the conical tapered section during operation of the fluid pump mechanism to determine an operating condition of the fluid pump mechanism based on a detected width of an interrogated location of the conical tapered section.