title: An improved signal processor for the ultrasonic dimension gauge.
abstract: The flip-flop producing a pulse proportional to the transit time of an ultrasonic burst between two piezoelectric crystals was often reset by transmission artefacts in sonomicrometers. A design improvement was made. The insertion of two monostable vibrators and one nand gate corrected the resetting caused by transmission artefacts. The new design produced a flip-flop pulse that was proportional to the transit time of the ultrasonic burst through the aorta. Ascending aortic diameter was monitored in unanaesthetised dogs for 6 to 8 weeks using the new design.
mesh_terms: D000818:Animals; D001011:Aorta / Q000033:anatomy & histology*; D001699:Biometry; D004285:Dogs; D004582:Electronics, Medical; D005260:Female; D008297:Male; D008991:Monitoring, Physiologic / Q000295:instrumentation; D014465:Ultrasonics / Q000295:instrumentation*; D014463:Ultrasonography