Injection device

Inventors

Kühnle, Sarah • Kistler, Tobias • Wurmbauer, Werner • Lauchard, Gerhard

Assignees

Vetter Pharma Fertigung GmbH and Co KG

Abstract

An injection device has a plunger for displacing a stopper in a syringe or carpule, a holder for the plunger, a drive for the axial displacement of the holder of the plunger, and a control device functionally assigned to the drive. The plunger, or at least a subcomponent thereof, relative to the holder, the holder is able to move over a limited distance relative to the plunger or a subcomponent thereof, opposing a pretensioning force, in that a sensor device is included which detects the relative position of the plunger, or at least a subcomponent thereof, relative to the holder, which comprises at least one sensor element which works together with the control device. The control device is designed such that, upon activation of the sensor element, the speed of advancement of the holder of the plunger is at least reduced.

Core Innovation

The invention relates to an injection device in which a plunger for displacing a stopper in a medical hollow device is provided with a base body and a subcomponent. A holder for the plunger is axially displaceable, and the holder can move over a limited distance relative to the plunger or the subcomponent to oppose a pretensioning force. The limited relative movement is used to avoid unintended displacement of the stopper.

A sensor device detects a relative position of the plunger or the subcomponent relative to the holder, and at least one sensor element works together with a control device. Upon activation of the sensor element, the control device reduces the speed of advancement of the holder of the plunger and can stop the drive speed when the sensor element is activated before sustained force would otherwise unintentionally displace the stopper.

Two embodiments are described: a hollow-cylinder plunger base with an internal space and a switch plunger subcomponent arranged to allow movement in the internal space, where the switch plunger is biased by a spring or pretensioning force toward a limit stop; and a solid plunger with a relative sliding mounting inside the holder, biased by a spring, with a microswitch actuating arm that detects relative position and triggers stop-then-reduce or stop drive behavior. The disclosed functionality includes controlled stopper contact and behavior for dual-chamber carpules, including priming and mixing for dual-chamber carpules.

Claims Coverage

The partial claim set includes two independent claims. The independent claims are directed to an injection device with an axially displaceable holder that moves over a limited distance against a pretensioning force and a plunger configuration in which a hollow-cylinder base body contains an internal space accommodating a switch plunger subcomponent, with one independent claim additionally requiring sensor-based control of holder advancement speed when the sensor element is activated.

Across the independent claims, the coverage centers on an injection device having an axially displaceable holder that moves a limited distance against a pretensioning force, combined with a plunger defined by a hollow-cylinder base body with an internal space and a switch plunger subcomponent. One independent claim further includes a sensor device and control device that reduce the speed of advancement when the sensor element is activated.

Stated Advantages

Documented Applications