Limiting life time of dispense assembly

A medical device for delivering at least one drug agent, the medical device comprising:

• a main body configured to contain at least one reservoir, said at least one reservoir containing said at least one drug agent;
• a sensor;
• a control unit;
• and
• an attachable dispense assembly, said dispense assembly configured to provide at least a part of a fluid channel and to be in fluid communication with said at least one reservoir when said dispense assembly is attached to said main body, such that upon attachment of a needle assembly to said dispense assembly attached to said main body, a fluid communication path is provided from said at least one reservoir, through said dispense assembly, and to said needle assembly,
• wherein said dispense assembly comprises a mounting hub configured for releasable attachment to the needle assembly,
• wherein said sensor is configured to detect attachment of said dispense assembly to said main body,
• wherein said control unit is configured to start a timer when said sensor indicates attachment of said dispense assembly,
• wherein said control unit is configured to determine, based at least in part on a signal from said sensor, whether an end of life of said dispense assembly is reached, wherein said end of life of said dispense assembly is determined based on a determination that an elapsed time since attachment measured by the timer exceeds a time limit, and wherein the time limit is variable and based on a temperature of said dispense assembly, a number of uses of said dispense assembly, and/or an identity of said dispense assembly, and
• wherein said medical device is configured to indicate said end of life of said dispense assembly.