Rotary Sensor Module with Resynchronization Feature

摘要

Drug delivery device comprising expelling means allowing a user to set a dose corresponding to a number of increments from an initial state, an indication member adapted to rotate in a first direction corresponding to the set dose, and rotate in an opposed second direction corresponding to an expelled dose, the indication member having an initial rotational position corresponding to both the initial state and the fully expelled dose state. Sensor means having an incremental counter synchronized with the rotational position of the indication member and having a reference point corresponding to the initial rotational position of the indication member. After detecting an error state the sensor means is adapted to re-synchronize by detecting the number of rotational increments for a set dose and for a subsequent expelled dose. If the numbers are identical the reference point is reset corresponding to the current rotational position of the indication member.

主权项

1. A drug delivery device comprising:
a housing, a drug-filled cartridge or structure for receiving a drug-filled cartridge, the cartridge comprising an axially displaceable piston and a distal outlet portion, drug expelling structure comprising:
dose setting structure allowing a user to set a dose of drug to be expelled, the dose corresponding to a number of increments from an initial state,an axially displaceable piston rod adapted to move the piston of a cartridge in a distal direction to thereby expel drug from a cartridge,an indication member adapted to rotate in a first direction relative to the housing and corresponding to the set dose, and rotate in an opposed second direction relative to the housing and corresponding to an expelled dose, the indication member having an initial rotational position corresponding to both the initial state and the fully expelled dose state, andactuation structure for expelling a set dose, the drug expelling structure being in an expelling state during expelling of a dose, sensor structure having a synchronized state in which an incremental counter is synchronized with the rotational position of the indication member and has a reference point corresponding to the initial rotational position of the indication member, the sensor structure being adapted to detect:
the number of rotational increments performed by the indication member in the first direction corresponding to a set dose,the number of rotational increments performed by the indication member in the second direction corresponding to an expelled dose,an expelling state for the expelling structure, anda non-synchronized error state,  wherein, when a non-synchronized error state is detected, the sensor structure is adapted to automatically re-synchronize by:
detecting the number of rotational increments for a set dose,in the expelling state, detecting the number of rotational increments for a subsequent expelled dose, andif the two numbers of increments are the same, reset the reference point corresponding to the current rotational position of the indication member.