Professor F. Levent Degertekin at Georgia Institute of Technology has developed a miniature chip that can be inserted into a patient’s blood stream on a catheter to take three-dimensional ultrasound images from inside the heart, coronary arteries, and peripheral blood vessels. The 1.4 mm silicon chip does some signal processing, so all the data can be sent outside the body via 13 cables.
The chip uses two capacitive micromachined ultrasonic transducer (CMUT) ring arrays. The dual-ring array includes 56 ultrasound transmitters and 48 receivers, all working in the 20 MHz range. The donut-shaped array measures 1.5 mm in diameter with a 430 micron center hole to accommodate the catheter’s guide wire. The device operates on only 20 mW, thanks to power-saving circuits that shut down unneeded sensors. This also reduces the amount of heat being put into the patient’s body.
“Our device will let cardiac surgeons see the entire volume in front of them within a blood vessel,” says Degertekin. “It will give them the equivalent of a flashlight so they can see blockages ahead of them in occluded arteries. And it could reduce the amount of surgery done to clear blocked blood vessels.”
Researchers plan on developing a version that could guide cardiologists working on patients when they are in MRI machines. They also want to miniaturize the ultrasound chip and put it on a 400-micron diameter guide wire. Eventually, they foresee licensing the technology to a medical diagnostic firm for clinical trials that will warrant FDA approval.