For Homebound Students, a Robot Proxy in the Classroom John W. Adkisson for The New York Times Ivey Smith, right, a teacher in Sumter, S.C., speaking to Lexie Kinder, who was born with a chronic heart disorder, through a VGo robot. SUMTER, S.C. - Lexie Kinder solves problems during math class, earns gold stars from her teacher and jokes with classmates at her elementary school. All without leaving her living room. Born with a chronic heart disorder that weakened her immune system and made attending school risky, Lexie, 9, was tutored at her home in Sumter, S.C., for years. But this spring, her family began experimenting with an alternative - a camera-and-Internet-enabled robot that swivels around the classroom and streams two-way video between her school and house. "She immediately loved the robot," her mother, Cristi Kinder, said, of the device, called a VGo, which Lexie controls from her home computer. Lexie dressed up the robot, which is about the height of her third-grade classmates, in pink ribbons and a tutu, and she renamed it "Princess VGo." A small but quickly growing number of chronically ill students - at least 50 across the country - now attend school virtually with what are called "remote presence robots." The technology is still expensive (a VGo costs $6,000, in addition to $1,200 a year for maintenance and other costs) and imperfect (when the robot loses its Internet connection, it goes lifeless and must be pushed). And despite the fantasies of Lexie's classmates - "I want a robot so I can stay in bed all day," one 8-year-old said - such robots are mostly last resorts for children restricted to their houses or hospital rooms. As Web-based video becomes more prominent as a teaching tool, special education advocates say these robots are valuable alternatives to tutoring. About 23,000 students across the country are homebound or hospitalized each school year. They might not otherwise interact with classmates or could fall farther behind academically, advocates say. "Soon, these robots should be the price of an inexpensive laptop," said Maja Mataric, a computer science professor at the University of Southern California, who studies how robots help children with learning disabilities. They should make access to education much easier for students who are convalescing. Ms. Mataric's research focuses on using robots to teach social cues to children with autism. Children adapt far more quickly to the technology than adults and treat the machine like another classmate, she says. During a fire drill at one Texas school, students were so worried about the VGo that they insisted on escorting it out of the building to safety. The VGo is four feet tall, weighs 18 pounds and is shaped like a white chess pawn, with a video screen on its face. Lexie controls its movement with her computer mouse. Video of the classroom at Alice Drive Elementary School appears on her computer screen, and video of her face appears on the robot's display screen. The robot and Lexie's computer support two-way voice communication, and Lexie can flash her VGo's lights to get the teacher's attention. Since 2007, VGo, based in Nashua, N.H., has been selling the robots to company executives who want to keep an eye on employees while traveling and to doctors, who use it to "visit" patients at different hospitals. Two years ago, it realized schools might be a new market. The first classroom model was sold to a school in Knox City, Tex., to be used by a child with an immune deficiency. The company's big break came during this year's Super Bowl. Verizon, which provides the LTE wireless connection for the robot, ran a commercial about a student using VGo. Before the ad, VGo had sold about 10 robots to schools. Since then, they have sold about 40. Most robots are bought with state or local money marked for disabled students, but at some schools, parents have held fund-raising events or bought the robot themselves. In Huntsville, Tex., education officials bought five VGos last year and are planning for five more next year. They named the program "Morgan's Angels" after a student with cancer who missed school for six months but was able to attend remotely with the robot's help. For students like Connor Flanagan, 14, of Tyngsborough, Mass., the main benefit has been social interaction. He does not go to school because of a rare lung condition, but he has stayed in touch with friends while awaiting a transplant. "He walks down the hallway kind of like everybody else," his mother, Jennifer Flanagan, said. The kids - aside the fact that it was a robot - they treated him like Connor. He'd roll through the room, and you'd hear "Hey, Connor. Hi, Connor." "