The present invention relates to a spring-loaded medical injection device for automatically ejecting set doses of a drug having an injection button (10). The injection device comprises a housing having a dose setting member (20) for straining an injection spring when setting the size of the dose to be injected and a release element (30) for releasing the strained injection spring to eject the set dose. The injection button (10) is movable in a distal direction against the bias of a return spring (1) and movable in a proximal direction by the force of the return spring (1). Further, the injection button (10) moves with it the release element from a first position to a second position. The release element (30) is further coupled to the injection button (10) by a plurality of fingers (31, 15) which disengages the injection button (10) from the release element (30) in the first position and engages the injection button (10) with the release element (30) in the second position, such that the injection button (10) can move a distance axially independently of the release element (30) in the first position and the injection button (10) and the release element (30) move axially together in the second position.

The present disclosure is generally directed to a drive mechanism for use in a drug delivery device having a cylindrical cartridge, i.e. a handheld injection device for selecting and dispensing a number of user variable doses of a medicament. The drive mechanism includes a base element, a toothed piston rod, which is guided within and movable relative to the base portion, and a drive gear having a pinion, which is rotatably held in the base element and in meshed engagement with the toothed piston rod. The toothed piston rod includes multiple rigid rod pieces which are connected by hinges. The rigid rod pieces comprise a flat plate provided with a straight toothed rack.

The present invention relates in a first aspect to a multi-state ratchet mechanism for a drug injection device. The multi-state ratchet mechanism comprises a ratchet gear member and a cooperating ratchet pawl member. An annular inner surface of the ratchet gear member comprises a first ring shaped surface portion with a first predetermined cross-sectional profile comprising a first asymmetrical toothing arranged at a first axial position of the inner annular surface. The annular inner surface of the ratchet gear member further comprises a second ring shaped surface portion arranged at a second axial position of the inner surface axially spaced apart from the first axial position. The second ring shaped surface portion comprises a second predetermined cross-sectional profile differing from the first predetermined cross-sectional profile. The ratchet pawl member is axially displaceable between the first ring shaped surface portion and the second ring shaped surface portion to provide first and second operating states, respectively, of the multi-state ratchet mechanism. The first operational state of the multi-state ratchet mechanism provides unidirectional rotation between the ratchet gear member and the ratchet pawl member in a first direction. The present multi-state ratchet mechanism is particularly suitable for drug injection devices such as user operated drug injection devices for administration of insulin for treating diabetes.

A medication injection pen, including a housing, a dose set knob (DSK) comprising an internal key, and a dose stop member engaging the dose set knob. Rotation of the dose set knob to set a medication dose causes rotation of the dose stop member with respect to the dose set knob, and when the dose set knob is rotated to a last dose setting position, the dose stop member rotationally abuts the internal key thereby preventing further rotational movement of the dose set knob in a dose setting direction.

A drive mechanism for a drug delivery device having a rotationally fixed plunger rod driven by a lead screw. The lead screw engages a free lock which is coupled to a release knob. A dose setting dial cooperates with an inner cylinder using a clutch to establish the axial movement of the plunger rod during dose setting and dispensing.

Described is a dose tracking mechanism for a drug delivery device, including an RFID device with an electric circuit and a switch operable to open and close the electric circuit to transmit a wireless signal to a receiving device when the electric circuit is closed by the switch. The switch is configured to open and close in response to operation of a dose setting and/or a dose dispensing mechanism of the drug delivery device, and the closing and opening of the electric circuit generates a pulse of the wireless RFID signal. In one embodiment, each pulse corresponds to a unit of a dose of medicament set by the dose setting mechanism or dispensed by the dose dispensing mechanism from a drug container of the drug delivery device, depending on if the dose setting or dose dispensing mechanism is arranged to toggle the switch.

A medication injection pen (50) includes a housing (1) and a dose set knob (2) rotatably connected to the housing (1) for setting a dose. An indicator member (200) is movable between a visible position indicating a zero position of the dose set knob (2) and a non-visible position indicating a non-zero position of the dose set knob (2). The indicator member is visible to a user in the visible position and not visible to the user in the non-visible position. The dose set knob is in the zero position when a set dose has been completely administered. Accordingly, a visible indication is provided to the user when a set dose has been completely administered.

The present disclosure relates to a medication delivery device having a dose detection system and an associated control system configured to determine an amount of medication delivered from the medication delivery device based on the sensing of relative rotation within the medication delivery device. The relative rotation may occur between a dose setting member and an actuator and/or housing of the medication delivery device. The rotation sensing may involve piezoelectric sensing, more specifically repeatedly deforming a piezoelectric sensor with a mechanical force. The dose detection system may be a modular or integral component of the medication delivery device.

A mechanism unit for a drug delivery device, comprising a housing (10), a piston rod (30), and a dose setting and drive mechanism, which is configured to perform a dose setting operation and a dose delivery operation by transferring a delivery force to the piston rod (30) in order to drive the piston rod (30) in a distal direction in a dose delivery operation, wherein the dose setting and drive mechanism comprises a first drive member (40a), a second drive member (40b), and a clutch mechanism, which has at least two different states, a setting state and a delivery state, wherein, in the setting state, the second drive member (40b) is rotationally secured with respect to the housing (10) at least against rotation in a delivery direction, and wherein, in the delivery state, the second drive member (40b) is rotatable relative to the housing (10) in the delivery direction, wherein, in the setting state, the first drive member (40a) is rotatable relative to the second drive member (40b) at least in the delivery direction, and wherein, in the delivery state, the second drive member (40b) is rotationally locked to the first drive member (40a) at least against rotation of the second drive member (40b) relative to the first drive member (40a) in the delivery direction.

An injection device includes a housing; an actuation member movable between a first position relative to the housing and a second position relative to the housing, wherein the actuation member is arranged to inhibit a mechanical operation of the injection device when the actuation member is in the first position, and allow the mechanical operation of the injection device when the actuation member is in the second position; electronic circuitry; and an actuation sensing arrangement, wherein the actuation sensing arrangement is configured to detect movement of the actuation member from the first position relative to the housing to the second position relative to the housing, and wherein the electronic circuitry is configured to be activated in response to detection by the actuation sensing arrangement that the actuation member has moved from the first position relative to the housing to the second position relative to the housing.