Data collection device for attachment to an injection device

An injection system comprising:

• an injection device for expelling a number of user-selectable doses of a medicament, the injection device comprising:
• an elongated housing extending along an axial direction and configured to accommodate a cartridge filled with the medicament and sealed by a bung that is displaceable in a distal direction for expelling of the medicament,
• a dial member rotatable relative to the elongated housing during expelling of the medicament, and
• a trigger displaceable in the axial direction relative to the dial member to initiate or to control expelling of the medicament, wherein the trigger is configured not to rotate relative to the elongated housing during expelling of the medicament;
• and
• a data collection device attachable to the injection device, the data collection device comprising:
• a body attachable to the dial member,
• a sensor arrangement comprising a sensor and a sensed element, wherein the sensor is configured to detect a rotation of the body relative to the trigger during expelling of the medicament,
• a button attached to the body, wherein the button is axially displaceable relative to the body, and
• a processor arrangement configured to determine, based on the rotation detected by the sensor, an amount of the medicament expelled by the injection device.

An injection system comprising

• an injection device comprising a trigger, a dial member, and an expelling mechanism, and the injection device being configured such that during expelling of a medicament by the injection device, (a) a relative rotation occurs between the dial member and the trigger upon an advancement of the expelling mechanism of the injection device, and (b) the trigger is rotationally fixed relative to a housing of the injection device;
• and
• a data collection device comprising
• a body attachable to the dial member of the injection device,
• a button attached to the body, wherein the button is axially displaceable relative to the body and wherein the button is freely rotatable relative to the body and wherein the button comprises an end section that is configured to axially abut with an end face of the trigger,
• a sensor arrangement comprising a sensor and a sensed element, wherein the sensor is configured to detect a rotation of the body relative to the trigger during expelling of the medicament, and
• a processor arrangement configured to determine, based on the detected rotation, an amount of the medicament expelled by the injection device.

A data collection device attachable to an injection device, the data collection device comprising:

• a body attachable to a dial member of the injection device, the injection device comprising a trigger, the dial member, and an expelling mechanism, the injection device being configured such that during expelling of a medicament by the injection device, (a) a relative rotation occurs between the dial member and the trigger upon an advancement of the expelling mechanism of the injection device, and (b) the trigger is configured not to rotate relative to a housing of the injection device;
• a button attached to the body, wherein the button is axially displaceable relative to the body and wherein the button is freely rotatable relative to the body;
• a sensor arrangement comprising a sensor, wherein the sensor is configured to detect a rotation of the body relative to the button during expelling of the medicament;
• and
• a processor arrangement configured to determine, based on the detected rotation, an amount of the medicament expelled by the injection device.