John R. Klepper

Method and apparatus for ultrasonically detecting, counting and/or characterizing emboli

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.

Apparatus for measuring the characteristics of an ultrasonic wave medium

The present invention relates to an apparatus which determines the distribution of the attenuation slope coefficient on a real-time basis using the center frequency shift. In one embodiment, the phase difference between a received signal and a reference signal is determined using EXCLUSIVE OR gates or an inverse trigonometric relation stored in a ROM. The phase difference is input to a differentiator which outputs the center frequency shift of the received signal on a real-time basis. The center frequency shift is input to another differentiator which outputs the attenuation slope coefficient. In other embodiments, the received signal is distributed into received signal bands, having different center frequencies, and signal characteristics of the received signal bands are averaged to remove virtually all effects of spectrum scalloping in the time domain. Thus, the attenuation slope coefficient is obtained without the effects of spectrum scalloping using simple hardware and without Fourier transformation.

Scalable ultrasound PACS: evolving needs for multimode ultrasound image and data management

We propose a scalable approach to ultrasound PACS. The general lack of any network interface capability on a large percentage of installed ultrasound scanners limits the solution available in the near term. A staged implementation beginning with a small number of ultrasound scanners interfaced to a single networked acquisition station is proposed. Initial mini-PACS may provide better utilization of the shared resources, such as archive and print servers and imagers, which would be cost prohibitive in a one-machine-per-scanner configuration. As the system requirements grow and ultrasound systems add direct network support, mini-PACS performances can overcome the initial single acquisition node bottleneck encountered with video-capture based systems, and ultrasound PACS can be integrated into a full hospital-wide PACS.