Detecting reinsertion of a continuous glucose monitoring sensor

A continuous glucose monitoring (CGM) system comprising:

• a sensor configured to be inserted into skin of a user and to generate electrical signals indicative of a glucose level;
• a first memory having an identifier stored therein identifying the sensor;
• a second memory configured to store therein a plurality of sensor identifiers;
• and
• a processor in communication with the first and second memories, wherein the processor is configured to execute computer instructions to:
• read the identifier stored in the first memory;
• determine whether the identifier matches any previously-stored identifier in the second memory;
• store the identifier in the second memory in response to the identifier not matching any previously-stored identifier in the second memory;
• and
• determine whether the sensor has met a predetermined usage limit in response to the identifier matching a previously-stored identifier in the second memory.

A method of detecting reinsertion of a continuous glucose monitoring (CGM) sensor, the method comprising:

• reading an identifier of the sensor from a sensor unit memory via a processor executing computer instructions in response to activation of CGM;
• determining whether the identifier matches any previously-stored identifier in a second memory;
• storing the identifier in the second memory in response to the identifier not matching any previously-stored identifier in the second memory;
• determining whether the sensor has met a predetermined usage limit in response to the identifier matching a previously-stored identifier in the second memory;
• and
• stopping operation of the CGM in response to determining that the sensor has met its predetermined usage limit.