Microsensor Set to Broadcast Data from Inside the Heart or Blood Vessels

In a development reminiscent of the "pillcam" technology that transmits information from within the digestive tract, researchers have created a highly miniaturized signaling device capable of sending data from inside blood vessels or the heart.

Investigators at the Georgia Institute of Technology (Atlanta, USA) built a device that integrates ultrasound transducers with processing electronics on a single 1.4 millimeter silicon chip. The chip combines capacitive micromachined ultrasonic transducer (CMUT) arrays with front-end CMOS electronics technology to provide three-dimensional intravascular ultrasound (IVUS) and intracardiac echography (ICE) images. The dual-ring array includes 56 ultrasound transmit elements and 48 receive elements. When assembled, the donut-shaped array is 1.5 millimeters in diameter, with a 430-micrometer center hole to accommodate a guide wire.


The device operates on 20 milliwatts of power, which minimizes the amount of heat generated inside the body, and contains ultrasound transducers that operate at a frequency of 20 megahertz (MHz).

The investigators reported that they had tested and demonstrated the image quality of the system on a wire phantom and an ex vivo chicken heart sample. They successfully acquired volumetric imaging data from the ex vivo chicken heart at 60 frames per second without any signal averaging.

"Our device will allow doctors to see the whole volume that is in front of them within a blood vessel," said senior author Dr. F. Levent Degertekin, professor of mechanical engineering at the Georgia Institute of Technology. "This will give cardiologists the equivalent of a flashlight so they can see blockages ahead of them in occluded arteries. It has the potential for reducing the amount of surgery that must be done to clear these vessels."

"If you are a doctor, you want to see what is going on inside the arteries, and inside the heart, but most of the devices being used for this today provide only cross-sectional images," said Dr. Degertekin. "If you have an artery that is totally blocked, for example, you need a system that tells you what is in front of you. You need to see the front, back, and sidewalls altogether. That kind of information is basically not available at this time."

The study was published in the February 2014 issue of the journal IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

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