New device provides live 3-D images from inside blood vessels

Scientists have developed a catheter-based device that provides real-time 3-D imaging from inside the heart, coronary arteries and blood vessels.
The single-chip device could better guide heart surgeons and potentially allow more of patients' clogged arteries to be cleared without major surgery, researchers said.
The device integrates ultrasound transducers with processing electronics on a single 1.4 millimetre silicon chip.
On-chip processing of signals allows data from more than a hundred elements on the device to be transmitted using just 13 tiny cables, permitting it to easily travel through circuitous blood vessels.
The forward-looking images produced by the device would provide significantly more information than existing cross-sectional ultrasound, researchers said.

Researchers have developed and tested a prototype able to provide image data at 60 frames per second, and plan next to conduct animal studies that could lead to commercialisation of the device.

"Our device will allow doctors to see the whole volume that is in front of them within a blood vessel," said F Levent Degertekin, a professor in the George W Woodruff School 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," Degertekin said.

"If you're 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," Degertekin said.
"If you have an artery that is totally blocked, for example, you need a system that tells you what's 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," Degertekin said.
Imaging devices operating within blood vessels can provide higher resolution images than devices used from outside the body because they can operate at higher frequencies.

However, operating inside blood vessels requires devices that are small and flexible enough to travel through the circulatory system. They must also operate in blood.
Doing that requires a large number of elements to transmit and receive the ultrasound information. Transmitting data from these elements to external processing equipment could require many cable connections, potentially limiting the device's ability to be threaded inside the body.
Degertekin and his colleagues addressed that challenge by miniaturising the elements and carrying out some of the processing on the probe itself, allowing them to obtain what they believe are clinically-useful images with only 13 cables.