An improved signal processor for the ultrasonic dimension gauge

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology

Background:

• Sonomicrometers use ultrasonic transit time for diameter measurement.
• Transmission artifacts frequently caused errors in previous sonomicrometer designs, leading to inaccurate readings.

Purpose of the Study:

• To improve sonomicrometer design by eliminating reset errors caused by transmission artifacts.
• To develop a reliable method for monitoring ascending aortic diameter.

Main Methods:

• Modified the sonomicrometer circuit by incorporating two monostable vibrators and one NAND gate.
• Tested the improved design by monitoring ascending aortic diameter in unanaesthetised dogs over 6-8 weeks.

Main Results:

• The enhanced design successfully corrected resetting errors caused by transmission artifacts.
• The new flip-flop pulse accurately reflected the ultrasonic burst transit time through the aorta.

Conclusions:

• The improved sonomicrometer design provides a reliable and artifact-free method for measuring aortic diameter.
• This technology facilitates long-term, non-invasive monitoring of cardiovascular parameters in animal models.