Optical detection of medical pump rotor position

A pump rotor for a medical pumping apparatus, said medical pumping apparatus having a motor, an emitter, and a detector, said pump rotor comprising:

• a receiver constructed and arranged for engaging a motor shaft, said motor shaft defining an axis of rotation and supporting the pump rotor when engaged by the receiver;
• a surface transverse to the axis of rotation, said surface comprising a reflective portion for reflecting electromagnetic radiation and a non-reflective portion that does not reflect electromagnetic radiation;
• wherein:
• the motor rotates the pump rotor via the shaft;
• the emitter emits electromagnetic radiation onto the surface of the pump rotor, said emitter being positioned to sequentially emit electromagnetic radiation on the reflective and non-reflective portions of the surface of the pump rotor as the pump rotor rotates about the axis of rotation;
• and
• the detector is positioned to receive electromagnetic radiation reflected by the surface of the pump rotor.

A method of detecting rotation of a rotatable assembly in a medical pumping apparatus comprising:

• providing a surface on the rotatable assembly having a reflective portion for reflecting electromagnetic radiation and a non-reflective portion that does not reflect electromagnetic radiation;
• emitting electromagnetic radiation onto the surface of the rotatable assembly such that as the rotatable assembly rotates, the reflective portion and the non-reflective portion of the surface of the rotatable assembly sequentially pass through the electromagnetic radiation emitted by the emitter;
• receiving electromagnetic radiation reflected by the surface of the rotatable assembly at a detector of the medical pumping apparatus;
• and
• providing a detection signal in response to receiving electromagnetic radiation reflected by the surface of the rotatable assembly at the detector.

A medical pumping apparatus comprising:

• a pumping mechanism including a disk having a surface with a reflective portion for reflecting electromagnetic radiation and a non-reflective portion that does not reflect electromagnetic radiation;
• a motor for rotating the pumping mechanism;
• an emitter for emitting electromagnetic radiation, said emitter positioned to emit electromagnetic radiation sequentially on the reflective and non-reflective portions of the surface of the disk as the pumping mechanism rotates;
• and
• a detector for receiving electromagnetic radiation reflected by the surface of the disk and providing a detection signal indicative of the received electromagnetic radiation for monitoring rotation of the pumping mechanism.