BACKGROUND

The present disclosure relates to an electronic dose detection system for a medication delivery device and/or a module adapted to removably attach to a proximal end portion of a medication delivery device. The dose delivery detection system is operable to detect data for determining the amount of a dose of medication delivered by the medication delivery device.

Patients suffering from various diseases must frequently inject themselves with medication. To allow a person to conveniently and accurately self-administer medicine, a variety of devices broadly known as pen injectors or injection pens have been developed. Generally, these pens are equipped with a cartridge including a piston and containing a multi-dose quantity of liquid medication. A drive member is movable forward to advance the piston in the cartridge to dispense the contained medication from an outlet at the distal cartridge end, typically through a needle. In disposable or p refilled pens, after a pen has been utilized to exhaust the supply of medication within the cartridge, a user discards the entire pen and begins using a new replacement pen. In reusable pens, after a pen has been utilized to exhaust the supply of medication within the cartridge, the pen is disassembled to allow replacement of the spent cartridge with a fresh cartridge, and then the pen is reassembled for its subsequent use.

Many pen injectors and other medication delivery devices utilize mechanical systems in which members rotate and/or translate relative to one another in a manner proportional to the dose delivered by operation of the device. Systems to measure the relative movement of members of a medication delivery device have been developed in order to assess the dose delivered. Yet, systems integrated into the device or module for high volume manufacturing and repeatable accuracy during the product's lifecycle have been challenging to design. The administration of a proper amount of medication requires that the dose delivered by the medication delivery device be accurate. Many pen injectors and other medication delivery devices do not include the functionality to automatically detect and record the amount of medication delivered by the device during the injection event. In the absence of an automated system, a patient must manually keep track of the amount and time of each injection. Accordingly, there is a need for a device that is operable to automatically detect the dose delivered by the medication delivery device during an injection event, and/or overcome one or more of these and other shortcomings of the prior art.

SUMMARY OF THE DISCLOSURE

In one embodiment, a medication delivery device is provided, including a device body, a dose setting member attached to the device body and rotatable relative to the device body about an axis of rotation during dose delivery. The dose setting member includes a sensed element including surface features radially-spaced from one another about the axis of rotation of the dose setting member. An actuator or a dose button is attached to the device body. The sensed element is rotatable relative to the dose button during dose delivery in relation to the amount of dose delivered. A rotational sensor includes a movable element contactable against the surface features of the sensed element. The dose button may be configured to house the rotational sensor. The movable element is positioned to move over the surface features during rotation of the sensed element relative to the dose button during dose delivery. The rotational sensor is configured to generate a signal in response to the movement of the movable element over the surface features during the rotation of the dose setting member. A controller is operatively coupled to the rotational sensor and may be housed by the dose button or a module. In response to receiving the generated signal from the rotational sensor, the controller is configured to determine a number of the surface features passing the movable element of the rotational sensor during dose delivery.

In another embodiment of a medication delivery device, an actuator has a first position in which a movable element of a rotational sensor is disengaged from axially extending surface features, and a second position in which the movable element of the rotational sensor is contactable with the axially extending surface features. The actuator may be a dose button. When the actuator is in the second position, a controller is configured, upon receiving a signal indicative of contact with an initial first one of the axially extending surface features, to activate the controller to a full power state, and the controller is configured, upon receiving a signal indicative of contact with a subsequent one of the axially extending surface features after the initial first one, to determine a number of the axially extending surface features passing the movable element of the rotational sensor during dose delivery.

