Ole: the brain surgeon with a difference

Press, 6 December 1985, Page 11

Ole: the brain surgeon with a difference

From

ROGER HIGHFIELD,

in London

Ole is a brain surgeon with a difference. The steady-handed, $35,000 robot helps neurosurgeons at the Memorial Medical Centre in Long Beach, California, perform brain surgery with greater precision and in less time than previously possible. It is used in “stereotactic” surgery where a surgical instrument is guided to a pre-determined point in the brain without directly looking at the site. The robot uses high resolution Eictures of a slice through a human rain, taken with a computer-aided tomography (CAT) scanner, to calculate the trajectory of a probe used to take brain tissue samples. Since April, it has been successfully used in seven operations. Ole, named after a hospital benefactor, consists of a Puma robot arm, made by Unimation, controlled by a minicomputer. The Memorial researchers, led by Dr Yik San Kwoh, director of tomography research, use it in brain surgery as follows:

First, the patient’s head is bolted into a restraint using stainless steel tipped screws, ensuring it cannot be moved during the operation. A CAT scanner is used to take images of cross-sections of the patient’s skulk The patient is then slid out of the scanner into Ole’s work area. Dr Kwoh selects the target area on the CAT scan, say a suspected tumour, and Ole works out the corresponding point in the patient’s brain in terms of its own location in the operating theatre. Dr Kwoh guides Ole to an appropriate entrance point where he uses it as a guide to bore a “burr hole” through the skull. When

the surgeon inserts the probe, which resembles a hypodermic needle, Ole constantly checks that it stays on course and prevents it from penetrating too deep. Throughout the process of taking the tissue sample the patient is under local anaesthetic and remains conscious.

During conventional brain surgery the entrance position and trajectory of the probe are calculated from the two-dimensional CAT scans by the surgeon. Then comes the laborious process of setting up the position and trajectory of the probe on the “surgeon’s sextant” — a complicated stereo- , tactic frame bolted to the patient’s head.

With Ole, operating times are cut from three hours to 45 minutes. Most important, Ole removes human error by calculating the possible probe trajectories directly from the scans.

Ole is extremely accurate — to 1/2000 of an inch. As a result less brain tissue is destroyed during the procedure and the size of the bunhole can be cut down to around % inch in diameter. Ole is also more flexible. It is simple to move and can reach any area; in the conventional method there are occasions when the stereotactic frame obscures entrance points on the skull. In future, it is hoped that Ole will be able to drill the burr hole automatically. Another modification may be to arm it with a laser scalpel Two other research groups, one in the United States, and the other in West Germany, are developing similar robot systems..

Copyright — London Observer'