After more than 2 1/2 years of physical therapy and electronic stimulation, stroke victim Mike Marin still couldn't open a door with his left hand. Now, thanks to a robot, Marin can open a door and his atrophied left arm isn't completely useless anymore.

Marin is at the forefront of what may seem an unlikely use for robots: providing the caring human touch.

For three months in rehab at a suburb north of New York, an unnamed and unlikely looking robot guided his arm repeatedly through an ordinary video game.

"I still got a long way to go," said the New York City computer network specialist who had a stroke two days before his 40th birthday.

He's one of about 300 stroke patients in experimental studies with a robot that's a cross between an exercise machine and video game. And many of these patients, who wouldn't normally get better, are showing significant improvement.

"We're able to show consistently better outcome with therapy using robots rather than conventional standard care," said his MIT colleague, Neville Hogan.

At the University of Southern California, Maja Mataric, who runs the robotics center, is also using robots therapy on stroke patients. Unlike Hogan's robots, Mataric's are more like a coach, using humor and personality, to guide patients through monotonous therapy.

She's also about to test robots as therapy aids for autistic children, with recent studies showing that they "have a fascination with repetitive mechanical things".

"Nursebot" (a robot which took on male and female personalities of Earl and Pearl depending on the gender of the voice used at the time) has also been tried out with elderly patients in Pittsburgh.

Sebastian Thrun, developer of Nursebot and director of Stanford University's artificial intelligence lab, said robots are making inroads into the health care community for the repetitive tasks of taking people to the restroom and reminding them to take medicines.

June Green, an able-bodied patient who tested the arm robot as part of a control group, is strapped in again in a chair for another robotic spin. If she fails to guide the joystick correctly, the robot takes over, moving her entire arm.

"You can feel it guide you," Green said. "It feels kind of funny because you're not in control."