VOA标准英语2015--Tiny Camera Sees Inside Blood Vessels（在线收听）

Tiny Camera Sees Inside Blood Vessels

Ahead of any surgical procedure, doctors try to learn as much as possible about the state of the organs they plan to operate on.  A new camera developed in the Netherlands can now make that easier - giving surgeons an incredibly detailed look inside blood vessels, all the way to the patient’s heart.  

Blockages in coronary arteries, caused by the buildup of plaque, are the main cause of heart attacks.  In most cases, doctors treat the problem by widening the artery with a mechanical device called a stent, inserted at the end of a long thin wire-like catheter.

But within a year, about 10 percent of patients have to return for another procedure, says cardiologist Evelyn Reger.

“Roughly half of the patients have to come back because we did not do an excellent job in the blockage that is causing the heart attack, and the other half of the patients have to come back because we overlook additional lesions, problems that are present in the artery," she said.

This situation could improve considerably with a new camera that provides a clearer, more detailed view from inside arteries, developed at the Erasmus Medical Center in Rotterdam, Netherlands.

Currently, to take different images through the catheter, surgeons control the rotation of the catheter's camera from outside the body. The new camera has its own tiny electrical motor.

Professor Ton van der Steen is the head of Department of Biomedical Engineering at the Erasmus Medical Center.

“With this system you have rotation where exactly needs to be, only in the tip. So you have a micro-motor in the tip that can rotate and that's why it can rotate so fast and so accurately," said van der Steen.

Researchers are still experimenting on lab animals, but the results are stunning.

While catheter cameras now in use take only about 100 images per second, too slow not to be distorted by the movement of the heart, the new camera can take 2,500 images in-between two heartbeats.

Its one millimeter-thick motor rotates a mirror 5600 times per second, while a fast-pulsing laser lights up the environment, allowing the camera to take sharp pictures of the artery wall.

“Suddenly we get a view on a blood vessel like we just know from the text book. And we can see that in our living patients at the very moment when we have to do the operation," said Reger.

Scientists say they are now trying to build an even smaller motor, only half a millimeter thick.

The new catheter camera was presented at the Optics in Cardiology symposium in Rotterdam on March 11, but researchers say it will take up to three years before they start with trials on humans.