Echocardiography vendors expand power and utility of ultrasound

Toshiba uses cardiac segment for digital launch

Technological competition in echocardiography intensified this month with the introductionof two significant works-in-progress at the American Society ofEchocardiography meeting in San Francisco. Toshiba and Hewlett-Packardboth accorded heavy R&D resources to their new scanners, butthe two ultrasound vendors took different tacks in pricing thesystems.

Cardiac segment leader Hewlett-Packard will completely revampits product line with the introduction of a new echocardiographyplatform and two systems, HP Sonos 2500 and HP Sonos 2000 (seestory, page 4).

Tustin, CA-based Toshiba America Medical Systems, meanwhile,chose the cardiac imaging segment by throwing its hat into thedigital ultrasound ring with its new PowerVision echocardiographysystem. PowerVision will offer extremely high frame rates andrapid parallel processing of digital image data. The system willsell for a premium over HP's 2500 once it is certified by theFDA, said Phil Smith, vice president of ultrasound business operations.

PowerVision converts the analog ultrasound signal to digitaldata immediately after the preamplifier, which is directly connectedto the transducer. Digital delay lines are substituted for analogdelay lines. The digital circuitry cuts the delay period to atenth of the time or less compared with standard analog systems,Smith said. Toshiba's digital echo system operates at up to 158frames per second in B-mode and 60 frames per second with colorDoppler.

"The price/performance (of PowerVision) is superior toother systems because of its digital capabilities and better framerate," Smith said.

Both Toshiba and Hewlett-Packard also adopted substantial redesignsof their scanner-user interfaces with their new technology, simplifyingthe physical configuration of control hardware and implementingmultiple application-specific software presets.

Four on the floor. PowerVision's digital circuitry, 32-bitCPU and parallel processing capabilities produce considerableenhancements in computational speed over previous ultrasound technology,with positive implications for image quality, according to Smith.

Quad Signal Processing, a major feature of Toshiba's new system,uses that improved digital speed to read four signals coming fromthe same returning beam with PowerVision's 128-channel transducers.

"Conventional (ultrasound) processing transmits and receivesone line of information per element," Smith said. "Weare able to go up to four (lines) simultaneously. It does thisso fast that we don't lose any time in going through all 128 elements(with QSP). The reason for this (speed) is that the digital delaycircuitry is faster than analog and we have the necessary computingpower."

PowerVision performs analog to digital conversion at approximatelythe same point as competitor ATL's Ultramark 9 HDI radiology system,Smith said. Toshiba's higher frame rate, however, makes its digitalsystem well suited to cardiac applications.

Toshiba also introduced a heart tissue analysis feature labeledtissue Doppler imaging, not to be confused with competitor Acuson'sDoppler tissue imaging. Toshiba again points to a higher framerate as a distinguishing factor between the two competing technologies.

TDI filters out blood-flow velocity and amplitude from theDoppler signal in order to paint a picture of heart tissue velocity.Where there is no velocity of the heart muscle, the tissue maybe stunned or dead, Smith said.

Each of PowerVision's transducers has an embedded integratedcircuit, which helps improve signal analysis and image quality,he said. Information on the physical characteristics of the particulartransducer is embedded in the chip. As the ultrasound signal returns,this information helps create uniformity in analyzing the effectof the signal on different elements.

"This will make the signal purer and produce greater fidelity.When a signal comes back through from a particular point in thebody, each element may look upon that a little bit differently,"Smith said.

Toshiba also showed a work-in-progress blood-flow quantificationtechnique at the ASE called automatic real-time flow quantification.The feature plots flow across the total vessel, with potentialquantification applications in the heart and other vessels.

Toshiba filed for 510(k) certification with the FDA last Julyfor PowerVision and hopes to receive the okay to begin shippingby this fall. PowerVision will sell in the $230,000 to $250,000price range, Smith said.