Analog Front End Helps Shrink Ultrasound Equipment
Packs more than 30 components in a chip measuring 9 x 9 mm
Charles J. Murray, Senior Technical Editor -- Design News, September 10, 2009
A new "analog front
end" chip plays a key role in delivering medical ultrasound capabilities to a
host of new locales, including ambulances, disaster sites and remote geographic
regions.
The new technology, developed by engineers at Texas Instruments (TI), packs between 30 and 40 electronic components into a single chip. As a result of its compactness, it enables medical product developers to shrink console-sized ultrasound equipment into handheld sizes.
"This technology cuts size by 70 percent and power by 40 percent, it still enables the ultrasound machine to maintain good image quality," says Veronica Marques, business development manager for Texas Instruments' Medical Business Unit.
Like all "analog front ends" (AFEs), the new product handles signals as they pass from an ultrasound machine's probe to its microprocessor. The new device, however, differs dramatically from predecessors in terms of size. Known as the AFE5851, it incorporates 16 variable gain amplifiers and eight 12-bit analog-to-digital converters, along with voltage-controlled attenuators (VCA), programmable gain amplifiers (PGA) and anti-aliasing filters in a single chip measuring about 9 x 9 mm. TI says it was able to reduce the size of the resulting package by developing a new architecture for the PGA and VCA, and by eliminating a low-noise amplifier from the package. The company claims that the AFE5851 is the first 16-channel AFE for the ultrasound market and is the smallest, lowest-power analog front end, as well.
"If you go back just two or three years, ultrasound designers were using big components," Marques says. "There was a minimum of 30 to 40 of those components making up one of these devices, and we've placed all of them on this single chip."
Moreover, the new integrated AFE architecture has cut power consumption. It consumes 39 mW per channel while operating at 32.5 megasamples per second.
TI engineers say the device serves as an enabler for portable ultrasound, not only because of its size, but also because of its low power draw. Together, the small size and low power draw have helped to deliver ultrasound capabilities to remote regions and rural locales where console-sized units can't be used.
"Whether it's for doctors in remote regions or medical technicians in first-respondent situations, there's a need for ultra-portable systems," Marques says. "This product is giving the ultrasound manufacturers a whole new market to go after."
