real thing. But she turned around when she heard Benson say, very distinctly, “Uh.”
Ellis stopped. “What was that?”
“Patient,” the anaesthetist said, gesturing toward Benson.
Ellis paused, bent over, to look at Benson’s face. “You all right, Mr. Benson?” He spoke loudly, distinctly.
“Yuh. Fine,” Benson said. His voice was deeply drugged.
“Any pain?”
“No.”
“Good. Just relax now.” And he returned to his work.
Ross sighed in relief. Somehow, all that had made her tense, even though she knew there was no reason for alarm. Benson could feel no pain, and she had known all along that his sedation was only that—a kind of deep, drugged semi-sleep, and not unconsciousness. There was no reason for him to be unconscious, no reason to risk general anaesthesia.
She turned back to the computer screen. The computer had now presented an inverted view of the brain, as seen from below, near the neck. The electrode track was visible end on, as a single blue point surrounded by concentric circles. Ellis was supposed to keep within one millimeter, one twenty-fifth of an inch, of the assigned track. He deviated half a millimeter.
“50 TRACK ERROR ,” warned the computer. Ross said, “You’re slipping off.”
The electrode array stopped in its path. Ellis glanced up at the screens. “Too high on beta plane?”
“Wide on gamma.”
“Okay.”
After a moment, the electrodes continued along the path. “40 TRACK ERROR ,” the computer flashed. It rotated its brain image slowly, bringing up an anterolateral view. “20 TRACK ERROR ,” it said.
“You’re correcting nicely,” Ross said.
Ellis hummed along with the Bach and nodded.
“ ZERO TRACK ERROR ,” the computer indicated, andswung the brain view around to a full lateral. The second screen showed a full frontal view. After a few moments, the screen blinked “ APPROACHING TARGET .” Ross conveyed the message.
Seconds later, the flashing word “ STRIKE .”
“You’re on,” Ross said.
Ellis stepped back and folded his hands across his chest. “Let’s have a coordinate check,” he said. The elapsed-time clock showed that twenty-seven minutes had passed in the operation.
The programmer flicked the console buttons rapidly. On the TV screens, the placement of the electrode was simulated by the computer. The simulation ended, like the actual placement, with the word “ STRIKE .”
“Now match it,” Ellis said.
The computer held its simulation on one screen and matched it to the X-ray image of the patient. The overlap was perfect; the computer reported “ MATCHED WITHIN ESTABLISHED LIMITS .”
“That’s it,” Ellis said. He screwed on the little plastic button cap which held the electrodes tightly against the skull. Then he applied dental cement to fix it. He untangled the twenty fine wire leads that came off the electrode array and pushed them to one side.
“We can do the next one now,” he said.
At the end of the second placement, a thin, arcing cut was made with a knife along the scalp. To avoid important superficial vessels and nerves, the cut ran from the electrode entry points down the side of the ear to the base of the neck. There it deviated to the right shoulder. Using blunt dissection, Ellis opened a smallpocket beneath the skin of the right lateral chest, near the armpit.
“Have we got the charging unit?” he asked.
The charger was brought to him. It was smaller than a pack of cigarettes, and contained thirty-seven grams of the radioactive isotope plutonium-239 oxide. The radiation produced heat, which was converted directly by a thermionic unit to electric power. A Kenbeck solid-state DC/DC circuit transformed the output to the necessary voltage.
Ellis plugged the charger into the test pack and did a last-minute check of its power before implantation. As he held it in his hand, he said, “It’s cold. I can’t get used to that.” Ross knew layers of vacuum-foil insulation kept the exterior cool and
editor Elizabeth Benedict