To quantify flow velocity in vascular structures in the upper gastrointestinal tract,
prototype ultrasound Doppler transducers having frequencies of 5 and 10 MHz were designed.
Connected to an advanced pulsed ultrasound Doppler meter via an isolation transformer
for patient safety, these transducers enabled the recording of flow velocity in vessels
within and surrounding the wall of the GI tract. This set up improves the endoscopic
ultrasound Doppler method by extending the measurable depth-range by using two frequencies,
permitting independent selection of measuring depth and sample volume length, and
giving an output format which includes full spectral analysis, simultaneous ECG and
capabilities of displaying two additional signals.
Ultrasound Doppler - Gastrointestinal endoscopy - Transducer - Blood velocity - Blood
vessels
