The invention relates to a sensor device for capturing data when carrying outfirst aidmeasures for reanimating a person affected by a cardiac arrest. The sensordevice isexactly positioned on the chest of the patient by means of a positioning-aidapparatus(5) and affixed by means of a fastening means (2). The thorax compressions,i.e., thepressing-in depth and compression frequency, are detectable by means of amotionsensor. A data-transfer interface allows communication, e.g. wirelesscommunication,with a mobile terminal.
