摘要 |
This disclosure relates to a noninvasive means for detecting, counting and characterizing emboli moving through the arterial or venous circulation. An ultrasonic transducer is applied to the skin or other tissues of the subject at sites such as over the temporal bone on either side of the head of the subject, on the neck, on the chest, the abdomen, arm, leg, within the esophagus, or surgically exposed organs or blood vessels. Using standard ultrasonic Doppler techniques, Doppler-shifted signals are located which are proportional to the blood flow velocity in the blood vessel(s) of interest. Spectral analysis is performed on the received signal using the fast Fourier transform or other appropriate technique to determine the frequency components in the Doppler shift spectrum. Further analysis of the spectra is used to delineate and characterize Doppler shift signals due to blood from Doppler shift signals due to emboli having a variety of compositions. |
申请人 |
INSTITUTE OF APPLIED PHYSIOLOGY AND MEDICINE, SEATTLE, WASH., US |
发明人 |
MOEHRING, MARK, A., SEATTLE, WA 98115, US;CURRY, MARK, A., SEATTLE, WA 98115, US;SPENCER, MERRILL, P., SEATTLE, WA 98105, US;KLEPPER, JOHN, R., SEATTLE, WA 98199, US |