Certain embodiments of a sensor cartridge element include a sensor module, an electrode arrangement installed on the sensor module, and a delivery arrangement securely coupled to the sensor module. The sensor module includes an analysis cell and a skin piercing member. The electrode arrangement generates an electrical signal when exposed to a fluid sample collected in the analysis cell. The delivery arrangement includes a drug reservoir, a piston chamber, and a valve arrangement providing selective fluid communication between the drug reservoir and the piston chamber. Metering electronics and an actuator can manage collection of fluid samples and/or dispensing of drug doses.