Monitoring unit

A monitoring unit for a medicament delivery device, the monitoring unit comprises;

• a housing comprising a longitudinal axis, a distal end and a proximal end;
• a monitoring circuit arranged in said housing that can detect and monitor functions of the medicament delivery device;
• an attachment mechanism arranged within the proximal end of the housing, where the attachment mechanism comprises a ring-shaped element having proximally directed releasable locking elements that are configured to releasably attach to a terminal distal end of an outer housing of the medicament delivery device such that when the monitoring unit is releasably attached to the medicament delivery device the housing of the monitoring unit extends distally from the outer housing of the medical delivery device;
• a tubular holding member positioned within the housing and having a plate-shaped contact member comprising a proximally directed surface that is traverse to the longitudinal axis;
• a releasable mechanical interface arranged on the proximally directed surface of the contact member that is configured to releasably interact with a mating mechanical interface arranged on the terminal distal end of the outer housing of the medicament delivery device;
• and
• an activation switch arranged to activate said monitoring circuit, wherein the activation switch is configured to activate the monitoring circuit in response to at least one of a removal of a protective cap, penetration of an injection needle, a start of a dose delivery sequence, and end of a dose delivery sequence, and a shielding of an injection needle.

An assembly comprising:

• a medicament delivery device including an activator element configured to be displaced in a distal direction from an initial position to an activation position in response to a movement of a drive element;
• and
• a monitoring unit for connection to a distal end of the medicament delivery device, the monitoring unit comprising:
• a housing comprising a longitudinal axis, a proximal end, and a distal end;
• a monitoring circuit arranged within the housing that detects and monitors functions of the medicament delivery device;
• an attachment mechanism positioned at the proximal end of the housing comprising a ring shaped connector having a proximally directed and radially flexible releasable locking tongue, where the releasable locking tongue releasably connects with the distal end of the medicament delivery device such that the monitoring unit extends distally and outwardly along the longitudinal axis away from the distal end of the medical delivery device;
• and
• an activation switch electrically connected to the monitoring circuit, where, when the activator element is in the activation position, the activator element acts on the activation switch to activate said monitoring circuit.