Guiding an injection cannula into a blood vessel - using an ultrasonic oscillatory locating device in a polystyrene holder

摘要

The locating oscillator is positioned at the rear of the cannula and is acoustically coupled to the cannula so that the ultrasonic waves produced travel along the cannula to the tip. Pref. the holder for the oscillator is made of a material with a high oscillatory resistance to the ultrasonic waves, such as polystyrene.