Decompression bubble detectors

摘要

A decompression bubble detector comprises a pulsed ultra-sound transmitter/receiver which is scanned across a cross-section of tissue and the total number of pulse echoes received in a preselected time interval is recorded. Changes in the total number of pulse echoes recorded in successive time intervals are used to monitor the decompression. A single transducer is scanned by means of a driven eccentric cam and a cam follower. A sin/cos potentiometer generates a signal related to the angular position of the transducer connected to a delay so that pulse counting can be arranged to coincide with the passage of the transducer across the target.