CPC A61M 5/31551 (2013.01) [A61M 5/31528 (2013.01); A61M 5/31585 (2013.01); A61M 2005/3125 (2013.01); A61M 2205/3306 (2013.01); A61M 2205/502 (2013.01); A61M 2205/52 (2013.01); A61M 2205/581 (2013.01)] | 14 Claims |
1. A medicament administration apparatus comprising
a housing;
a drug container;
a dose setting member allowing a user to set a medicament dose to be delivered, wherein the dose setting member is a dosage knob that does not rotate during a dose delivery;
a release member moveable in a distal direction to permit the dose delivery;
an indicator adapted to rotate relative to the housing during the dose delivery, wherein an amount of rotation of the indicator indicates a delivered medicament dose; and
a sensor arrangement comprising:
a sensor adapted to measure the amount of rotation of the indicator, wherein the sensor is permitted to move axially together with the indicator; and
a processor configured to determine an amount of medicament expelled by the medication administration apparatus based on the amount of rotation that the sensor measured,
wherein the sensor is a magnetic sensor,
wherein the indicator comprises plural magnets, the plural magnets being provided around a circumference of a surface of the indicator, and
wherein the magnetic sensor varies its output due to variations in a magnetic field as the indicator and the plural magnets rotate relative to the housing.
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