Medical injections and related devices and methods

An autoinjector comprising:

• a housing;
• a needle arranged at a distal end of the housing;
• a needle guard configured to expose the needle when an insertion force is applied to insert the needle into a user;
• a container disposed within the housing and configured to contain medicament;
• a plunger slidably disposed within the container;
• a plunger rod configured to push the plunger through the container to dispense the medicament through the needle when the container contains medicament and when the needle is exposed, wherein the plunger rod comprises one or more optical transmission regions;
• an optical mechanism configured to emit a first optical signal through at least one of the one or more optical transmission regions of the plunger rod and to receive the first optical signal, wherein a dispensing movement of the plunger rod enables transmission of the first optical signal;
• and
• an electrical mechanism configured to contact a portion of the needle guard, wherein a compression movement of the needle guard generates a first electrical signal.