Ultrasonic blood flow measurements: transcutaneous compared with implanted cuff

Experiments were undertaken in our laboratory to establish relationships between flow parameters calculated from implanted ultrasonic cuff signals and those obtained with a transcutaneous probe. Analog signals were received from crystals surgically implanted on the right carotid, right femoral, and abdominal aorta of a mature male beagle dog. Near these locations, transcutaneous measurements were made using a prescribed technique. From these ultrasonic signals, the following time dependent flow parameters were calculated: spatial velocities, velocity profiles, diameters, flows, and velocity frequency distributions. Using these measurements, a comparison between the implanted cuff and transcutaneous probe was made. In addition to high reproductibility, results confirm a strong correlation between the two techniques; consequently, the validity of the less traumatic transcutaneous method is substantiated.