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
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
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."