ARRANGEMENT AND METHOD FOR DETERMINING A STOPPER POSITION

摘要

The invention relates to an arrangement for determining a position (x) of a stopper (4) relative to a container (2) in a drug delivery device (1), comprising an acoustic source (5) configured to emit an acoustic signal and an acoustic sensor (6) configured to detect an acoustic signal, a processing unit (10) for controlling the acoustic source (5) and processing the detected acoustic signal for determining characteristics of the acoustic signal correlated with the position (x) of the stopper (4). Furthermore, the invention relates to a method for determining a position (x) of a stopper (4) relative to a container (2) in a drug delivery device (1), the method comprising the steps of:
- emitting an acoustic signal from an acoustic source (5),
- detecting an acoustic signal caused by the emitted acoustic signal by means of an acoustic sensor (6),
- processing the detected acoustic signal for determining characteristics of the acoustic signal correlated with the position (x) of the stopper (4) by means of a processing unit (10).