SACRAMENTO, Calif. — Dr. Alan Shatzel’s pager beeped at 9 on a Saturday morning. A man had suffered a stroke and someone had to decide, quickly, whether to give him an anti-clotting drug that could mean the difference between life and death.

Shatzel, a neurologist, hustled not to the emergency room where the patient lay — 260 miles away, in Bakersfield — but to a darkened room at a hospital here. He took a seat in front of the latest tools of his trade: computer monitors, a keyboard and a joystick that control his assistant on the scene — a robot on wheels.

He guided the roughly 5-foot-tall machine, which has a large monitor as its "head," into the patient’s room in Bakersfield. Shatzel’s face appeared on screen, and his voice issued from a speaker.

Shatzel acknowledged the nurse and introduced himself to the patient’s grandson, explaining that he would question the patient to determine whether he was a candidate for the drug. The robot’s stereophonic hearing conveyed the answers. Using the hypersensitive camera on the monitor, Shatzel zoomed in and out and swung the display left and right, much as if he were turning his head to look around the room.

For years, the military and law enforcement agencies have used specialized robots to disarm bombs and carry out other dangerous missions. This summer, such systems helped seal a BP well a mile below the surface of the Gulf of Mexico. Now, with rapidly falling costs, the next frontiers are the office, the hospital and the home.

Mobile robots are now being used in hundreds of hospitals nationwide as the eyes, ears and voices of doctors who cannot be there in person. They are being rolled out in workplaces, allowing employees in disparate locales to communicate more easily and letting managers supervise employees from afar. And they are being tested as caregivers in assisted-living centers.

"Computers are beginning to grow wheels and roll around in the environment," said Jeanne Dietsch, a veteran roboticist and co-founder of MobileRobots Inc., a robot maker in Amherst, N.H., and a division of Adept Technologies.

Skeptics say these machines do not represent a great improvement over video teleconferencing. But advocates say the experience is substantially better, shifting control of space and time to the remote user.

"Most of the existing videoconferencing technology is designed for meetings," said Pamela J. Hinds, co-director at the Center for Work, Technology and Organization at Stanford University. "That is not where most work gets done."

For now, most of the mobile robots, sometimes called telepresence robots, are little more than ventriloquists’ dummies with long, invisible strings. But some models have artificial intelligence that lets them do some things on their own, and they will inevitably grow smarter and more agile. They will not only represent the human users, they will augment them.

"The beauty of mobile telepresence is it challenges the notion of what it means to be somewhere," said Colin Angle, chief executive of one of the largest robot manufacturers, iRobot

The robot is what allowed Shatzel to "be" in the patient’s room far away. From an earlier telephone conversation with the emergency room doctor, the patient’s condition had not been clear. But in speaking directly with the patient, examining his face and control of his hands and glancing with the camera at the cardiac monitor in the room, Shatzel could assess the stroke, he said, with the same acuity as if he were there. He instructed the staff to administer the drug.

"We had a good outcome," he said later.

Dr. John Whapham, a Loyola University neurologist who has helped create several regional networks providing telemedicine with robots made by InTouch Health, says that when he began using the robot during his residency, he would carry his laptop in a backpack so he could perform consultations anytime.

"I’ll pull out the laptop, and when I’m on Michigan Avenue here in Chicago, put it on a garbage can or on the seat of a bus stop," he said. "You’re live, and you can walk around, examine, image, zoom in and out. I do it all the time."

EXPANDING THE WORKPLACE

"I’m very thin in this new outfit," Mike Beltzner says, breaking the ice in a room of Silicon Valley computer programmers. In the flesh, he is 2,200 miles away, at home in Toronto with his cat. But at this meeting his face appears on a 15-inch LCD display atop a narrow aluminum machine resembling an upright vacuum cleaner. Indeed, as this robot rolls around the room it looks as if it could just as easily be sweeping.

Beltzner rolls the robot to a large conference table in the Mountain View headquarters of Mozilla Corp., maker of Firefox, a popular Web browser. By swiveling his camera eye back and forth, he can see the entire room and chats comfortably with the assembled team.

An hour earlier, Beltzner, director of Firefox, was logged into a different robot on the other side of the building to attend the weekly all-hands meeting. With a pink lei on one shoulder and a jaunty cap on the other, the robot was surrounded by more than 100 young software engineers, each sitting with a wirelessly connected laptop.

Aside from the occasional greeting, no one seems to notice the disembodied Beltzner until he is called upon by Mary Colvig, a Mozilla marketing manager. She wants employees to share the chore of leading tours of the office each week.

"What do you want me to do?" Beltzner asks, his voice piping from twin speakers in the robot’s chest.

"I would like you to give tours," she responds from the front of the room. "That would be pretty insane."

When the meeting ends, "Robo-Beltzner" — as one colleague calls him — mingles in the large room, chatting. Then Beltzner executes a nifty pirouette and moves the robot, made by Willow Garage of Menlo Park, Calif., to a charging station.

Like many other Silicon Valley companies, Mozilla has employees around the world, and in the month since it began testing the system, as many as 10 employees have logged in to run errands, chat and attend meetings.

Beltzner has now used the Willow Garage robot for more than a month, usually four to six times a week to attend meetings and chat with his co-workers in Mountain View. He finds it to be a distinctly different experience from a video teleconference or a computer chat system.

"With the robot, I find that I’m getting the same kind of interpersonal connection during the meetings and the same kind of nonverbal contact" that he would get if he were in the room, he said. "It’s a lot easier to have harder conversations when I ‘roll the robot,"’ he added, referring to reviewing an employee’s performance or discussing technical issues.

There are few drawbacks to the robots, the company’s employees agree, although Erica Jostedt, a Mozilla communications manager, notes that the virtual Beltzner is ruder than his flesh-and-blood Canadian counterpart.

"I came to a meeting with him, and he didn’t even open the door for me!" she said, laughing.

The robot, of course, has no arms.

That has not stopped other programmers from commuting to Silicon Valley robotically.

Each morning for the past year, Chad Evans’ robot has sat with its back to a freeway in a double aisle of cubicles occupied by software designers at Philips Healthcare in Foster City, Calif.

Evans, a software designer himself, sits more than 2,000 miles away at home in Atlanta. But "Chadbot," a 4-foot-tall prototype built by RoboDynamics of Santa Monica, Calif., allows him to live where he chooses and work West Coast hours.

When he is sitting at his desk in Atlanta, Evans is visible in a small monitor at the top of the robot, which is usually plugged into a recharging station. His workmates can see at a glance whether he is available for a quick chat by simply peering down the aisle.

When Evans needs to go to a meeting in Foster City or visit a colleague, he drives the robot to a desk or a meeting room. If someone is willing to help him by pressing the elevator buttons, he can even visit other floors.

"Using Skype would require me to initiate a phone call," he said. "This gives me more of a passive ability. I’m just sitting here like I would be at my desk if I was in the office. I see people coming and going, and they see me and they think, ‘Oh yeah, there was something I wanted to ask Chad."’

It took a while for his co-workers to get used to Chad as Chadbot. "The first three weeks were the weirdest experience I’ve ever had," said Karl McGuinness, a software architect whose desk is adjacent to the robot. "You’d hear his voice and I’d think, ‘What the heck is going on?"’

THE BOSS, OR BIG BROTHER?

Tom Serani’s boss had grown frustrated that while Serani was on the road, his 20 salespeople working the phones back at company headquarters did not have the same zip as when he was in the office.

"The new guys were not doing quite as well," said the boss, Neal Creighton, a co-founder of RatePoint, a company based in Needham, Mass., that tracks Internet users’ opinions of products and companies.

When RatePoint was approached by Vgo Communications to test a mobile robot, Creighton jumped at the chance.

From his hotel room, Serani can roll a robot up to an office cubicle back at headquarters, listen in on a telephone sales pitch and offer advice.

Serani was initially skeptical. "I immediately saw the potential," he said. "It was more a question of ‘How do I position this so I don’t have my guys running out of the building calling the local reporters about how insane I am?"’

But in practice, he said: "Our sales team responded a lot differently to the robot than they did to the speakerphone. They were looking at it like it was a person, and their behavior patterns were completely different when it was here."

Still, the possibility that remotely operated robots might be used by some managers as surveillance devices, or as peeping Toms, has made some in the fledgling industry nervous.

"I don’t want this technology to be seen as a means of oppression," said Trevor Blackwell, founder and chief executive of Anybots, the maker of QB, a $15,000 mobile robot that balances on two wheels like a Segway and will be shipped commercially beginning this fall.

Others argue that the design of a robot determines how it will be perceived in the workplace. "Larger screens for showing the pilot’s video create a greater sense of presence, whereas little to none suggests surveillance," said Sanford Dickert, a Willow Garage executive.

There are also skeptics about the value of the current generation of mobile robots. "It’s cool, but it’s a little gimmicky," said Michael Arrington, founder and co-editor of the technology news website TechCrunch. Although he now lives much of the year in Seattle and manages his Silicon Valley website from afar, he said he would consider the robot as a stunt, perhaps for an interview, but not for running his company.

"You can walk around, but you can’t really see what’s going on," he said.

A TOOL FOR THE ELDERLY

All five of the U.S. companies that have announced or are already selling mobile robots are adding or experimenting with automation. For example, it will not be unusual for mobile robots in the next year to feature collision avoidance and lane-following technologies like those now offered in luxury automobiles. Already Vgo’s robot automatically parks itself when it is driven within a foot or two of its recharging station.

Such automated robots could help in caring for a rapidly aging population.

Vgo’s executives said they ultimately envisioned their robots being used by family members to pay visits and offer help to elderly parents, allowing them to remain independent longer. At the simplest, the Vgo robots could help workers in assisted-living homes check in on residents and make sure they were taking medicines at the correct time each day.

"We’re not replacing low-cost labor," said Brad Kayton, Vgo’s chief executive. "We’re acting as a supplement for it."

Others see the robots as a new means of mobility for the elderly, allowing them to stay in better contact with friends and family and visit museums and theaters, among other possible applications.

As technology advances, designers say, mobile robots will allow the elderly and others to do more than be in two places at one time. The robots will augment their human users, enhancing their senses by offering capabilities like better vision and hearing as well as futuristic skills like face recognition.

Still, no one believes the telepresence robots will be accepted without some resistance.

Lou Mazzucchelli, an expert in video teleconferencing, suggested that workers might make fun of their robot-enhanced managers behind their backs.

Moreover, there may be unpredictable consequences. The robots might become a new target for frustrated colleagues. "All of these products," he said, "are just begging me to kick them over."

© 2010 The New York Times Company