Rama II

8 BIOMETRY

The medical briefing had already be­gun when Francesca and General Borzov arrived. All the rest of the cosmonauts were present, as well as twenty-five or thirty additional engineers and scientists associated with the mission. Four newspaper reporters and a television crew completed the audi­ence. At the front of the small auditorium stood Nicole des Jardins, wearing her gray flight outfit as always, and holding a laser pointer in her hand. To the side of her was a tall Japanese man in a blue dress suit. He was listening carefully to a question from the audience. Nicole interrupted him to ac­knowledge the new arrivals.

“Sumimasen, Hakamatsu-sanr ” she said. “Let me introduce our com­mander, General Valeriy Borzov of the Soviet Union, as well as the journal­ist-cosmonaut Francesca Sabatini.”

She turned toward the latecomers. “Dobriy Utra,” Nicole said to the general, quickly nodding a greeting in Francesca’s direction as well. “This is the esteemed Dr. Toshiro Hakamatsu,” Nicole said. “He designed and devel­oped the biometry system that we are going to use in flight, including the tiny probes that will be inserted into our bodies.”

General Borzov extended his hand. “I am glad to meet you, Hakamatsu-san,” he said– “Madame des Jardins has made us all very much aware of your outstanding work.”

“Thank you,” the man replied, bowing in the direction of Borzov after shaking his hand. “It is an honor for me to be part of this project.”

Francesca and General Borzov took the two empty seats at the front of the auditorium and the meeting continued. Nicole aimed her pointer at a keyboard on the side of a small podium and a full-scale, multicolored male model of the human cardiovascular system, with veins marked in blue and arteries in red, appeared, as a three-dimensional holographic image in the front of the room. Tiny white markers circulating inside the flowing blood vessels indicated the direction and rate of flow. “The Life Sciences Board of the ISA just last week gave final approval to the new Hakamatsu probes as our key health monitoring system for the mission,” Nicole was saying. “They withheld their approval until the last minute so that they could properly assess the results of the stress testing, in which the new probes were asked to perform in a wide variety of off-nominal situations. Even under those condi­tions there was no sign that any rejection mechanisms were triggered in any of the test subjects.

“We are fortunate that we will be able to use this system, for it will make life much easier both for me, as your life science officer, and for you. During the mission you will not be subjected to the routine injection!scanning tech­niques that have been used on previous projects. These new probes are injected one time, maybe twice at the most during our one-hundred-day mission, and they do not need to be replaced.”

“How did the long-term rejection problem get solved?” came a question from another doctor in the audience, interrupting Nicole’s train of thought. “I will discuss that in detail during our splinter session this afternoon,” she replied. “For now, it should be sufficient for me to mention that since the key chemistry governing rejection focuses on four or five critical parameters, including acidity, the probes are coated with chemicals that adapt to the local chemistry at the implantation site. In other words, once the probe arrives at its destination, it noninvasively samples its ambient biochemical environment and then exudes a thin coating for itself that is designed to be consistent with the chemistry of the host and thereby avoid rejection. “But I am getting ahead of myself,” Nicole said, turning to face the large model showing blood circulation in the human being. “The family of probes will be inserted here, in the left arm, and the individual monitors will dis­perse according to their prescribed guidance programs to thirty-two distinct locales in the body. There they will embed themselves in the host tissue.” The inside of the holographic model became animated as she spoke and the audience watched as thirty-two blinking lights started from the left arm and scattered throughout the body. Four went to the brain, three more to the heart, four to the primary glands of the endocrine system, and the remaining twenty-one monitors spread out to assorted locations and organs ranging from the eyes to the fingers and toes.

“Each of the individual probes contains both an array of microscopic sensors to sample important health parameters and a fancy data system that first stores and then transmits the recorded information upon receipt of an enabling command from the scanner. In practice, I would expect to scan each of you and dump all your health telemetry once a day, but the recorders can handle data covering up to four days if necessary.” Nicole stopped and looked at the audience. “Are there any questions so far?” she asked.

“Yes,” said Richard Wakefield in the front row. “I see how this system gathers trillions of bits of data. But that’s the easy part. There’s no way you or any other human being could look at all that information. How does the data get synthesized or analyzed so that you can tell if anything irregular is happening?”

“You’d make a great straight man, Richard,” Nicole said with a smile. “That’s my next subject.” She held up a small, flat, thin object with a keyboard on it. “This is a standard programmable scanner that permits the monitored information to be sampled in many different ways. I can call for a full dump from any and!or all channels, or I can request transmission only of warning data…”

Nicole saw many confused looks in her audience. “I’d better back up and start this part of the explanation again,” she said. “Each measurement made by each instrument has an expected range — one that will vary of course from individual to individual — and a much wider tolerance range used to identify a true emergency. If a particular measurement only exceeds the expected range, it is entered in the warning file and that specific channel is marked with an alarm identifier. One of my options using the scanner is to read out only these warning lists. If an individual cosmonaut is feeling fine, my nor­mal procedure would be just to see if there are any entries in the warning buffer.”

“But if you have a measurement outside the tolerance range,” interjected Janos Tabori, who was the backup life science officer, “then watch out. The monitor turns on its emergency transmitter and uses all its internal power to send out a beep, beep noise that is frightening. I know, it happened to me during a short test with what turned out to be improper tolerance values. I thought I was dying.” His comment caused general laughter. The image of little Janos walking around emitting a high-pitched beep was amusing.

“No system is foolproof!” Nicole continued, “and this one is only as good as the set of values that are entered to trigger both the warnings and the emergencies. So you can see why calibration data is essential. We have ex­amined each of your medical histories with extreme care and entered initial values in the monitors. But we must see actual results with the real probes inserted in your bodies. That’s the reason for today’s activity. We will insert your probe set today, monitor your performance during the four final simula­tion exercises that begin on Thursday, and then update the trigger values, if necessary, before we actually launch.”

There was some involuntary squirming as the cosmonauts thought about the prospect of tiny medical laboratories indefinitely embedded in their criti­cal organs. They were accustomed to the regular investigative probes that were placed in the body to obtain some specific information, like the amount of plaque blocking the arteries, but those probes were temporary. The thought of permanent electronic invasion was disquieting, to say the least. General Michael O’Toole asked two questions that were bothering most of the crew.

“Nicole,” he inquired in his usual earnest manner, “can you tell us how you make sure that the probes actually go to the right places. Even more important, what happens if one malfunctions?”

“Of course, Michael!” she answered pleasantly. “Remember these things will be inside me as well and I had to ask the same questions.” Nicole des Jardins was in her middle thirties. Her skin was a shiny copper brown, her eyes dark brown and almond-shaped, her hair a luxurious jet black. There was an unshakable self-confidence radiating from her that was sometimes mistaken for arrogance. “You won’t leave the clinic today until we have verified that all the probes are properly positioned,” she was saying. “Based on recent past experience, one or two of you may have a monitor wander off course. It is an easy matter to track it with the lab equipment and then send overwrite commands as necessary to move it to the proper spot.

“As far as the malfunction issue is concerned, there are several levels of fault protection. First, each specific monitor tests its own battery of sensors more than twenty times a day. Any individual instrument failing a test is turned off immediately by the executive software in its own monitor. In addition, each of the probe packages undergoes a full and rigorous self-test twice a day. Failure of self-test is one of many fault conditions that causes the monitor to secrete chemicals causing self-destruction, with eventual harmless absorption by the body. Lest you become unduly concerned we have rigorously verified all these fault paths with test subjects during the past year. r

Nicole wound up her presentation and stood quietly in front of her col­leagues. “Any more questions?” she asked. After a few seconds” hesitation she continued, “Then I need a volunteer to walk up here beside the robot nurse and be inoculated. My personal probe set was injected and verified last week. Who wants to be next?”

Francesca stood up. “All right, we’ll start with la bella signora Sabatini ” Nicole said w.th uncharacteristic flare. She gestured to the television person­nel. Focus those cameras on the tracer simulation. It’s quite a show when these electronic bugs swarm through the bloodstream.”