Abstract: 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.

Abstract: A cardiac output measurement device for the real-time, non-invasive measurement of cardiac output that can be effectively operated by relatively unskilled personnel on a routine monitoring basis in a wide variety of office and hospital conditions. To accomplish this task, the system utilizes a pulsed Doppler ultrasound transducer directed through the suprasternal notch of a patient axially towards the blood flow in the ascending aorta. The device automatically searches the ascending aorta at various predetermined depths to find the depth at which the greatest quality blood velocity reading is detected. An examination is performed at that chosen depth and the device automatically calculates a patient's cardiac output from the Doppler measured velocity combined with an aortic diameter estimation made from the patient's height, weight, and age. The device automatically calculates cardiac velocity, cardiac index, stroke distance, heart rate, and stroke volume.