An injection device is described. The injection device includes a stopper having a first conductive element, a barrel having a medicament reservoir sealed at a proximal end with the stopper, and a plunger rod having a second conductive element. The plunger rod is coupled with the stopper to cause forward axial movement of the stopper to expel a medicament from the medicament reservoir. The first conductive element and the second conductive element complete an electrical circuit when the plunger rod is coupled to the stopper.