KANSAS CITY, Mo. — An intensive-care patient grimaces as she clutches her chest.

"Tell me about your chest pain," the physician inquires calmly. The woman reaches for a spot on the left side of her chest. "Right where your hand is?" asks the doctor. The woman nods.

Sounds routine — except the patient is at St. Luke's Hospital in Kansas City, Mo., and the physician is 20 miles away. The doctor is seated before a video screen and a bank of computers and monitors, watching and measuring the woman's vital signs in Lee's Summit, Mo.

The futuristic ICU monitoring system is the latest in a quiet medical revolution in which healthcare is increasingly delivered through broadband technologies — land-based and wireless networks that allow continuous communication of data, voice and video at ultra high speeds.

Medical innovations include wristwatches that monitor the heart, cell phones that can prick the finger of a diabetic patient and send the information to a doctor, and bedroom floor sensors that can discern an elderly patient's unsteady gait or even predict the onset of Parkinson's disease.

Supporters seeking to accelerate the use of these new technologies say they will not only make healthcare more accessible, but also improve treatments and reduce costs.

How much? A scholar with the Ewing Marion Kauffman Foundation and the Brookings Institution estimates savings of nearly $1 trillion.

While independent experts confirm these savings are realistic, they also complain the U.S. telemedicine revolution lags the rest of the world. Most Americans still don't have access to broadband, smaller hospitals can't afford the technology and current laws slow the approval process of the technology for medical use or make it hard to use across state lines.

In short, they say there is an urgent need for a national policy on telemedicine.

"The promise is gigantic for improving the quality of care and the convenience of care," said Steven Findlay, a health-care analyst at Consumers Union, which publishes Consumer Reports. "The writing is on the wall — it's just a matter of how we are going to get there."

In a report released last month, Robert E. Litan said expanding telemedicine to hospitals, doctors' offices, nursing centers and homes can in 25 years save billions by lowering medical costs, reducing institutionalized living and allowing seniors and people with disabilities to remain active in the labor force.

He said under the right policies, savings "could exceed what the United States currently spends annually for healthcare for all its citizens." Healthcare currently consumes 16 percent of the nation's gross domestic product.

Since last January, St. Luke's Health System has used its broadband network to monitor 66 ICU beds at three hospitals, allowing one on-call specialist to provide critical bedside care and respond to emergencies without stepping into a patient's room. It will expand to a fourth St. Luke's hospital this month.

Jennifer M. Ball, director of St. Luke's eICU system, said it was too early to say whether the system saves money. Ball said the priority is to provide constant and intensive monitoring of patients, which has been shown in studies to improve care.

So far, the eICU system, developed by Baltimore-based Visicu Inc., is used in 34 health systems serving 150 hospitals in 22 states, including an Air Force facility in Honolulu that monitors patients in Guam. Telemedicine is spreading "but this is still the tip of the iceberg," Ball said.

Cerner Corp. in North Kansas City has developed online technology to allow young diabetes patients to upload their glucose meters for faster feedback from caregivers. The service is used at Children's Mercy Hospital in Kansas City and is being marketed to hospitals elsewhere.

Still, barriers remain that slow telemedicine's growth, said Russell Bodoff, executive director of the Center For Aging Services Technologies, which last month made a presentation at a White House conference.

One major barrier is that only 40 percent of Americans have access to broadband. That compares with 75 percent in Japan and South Korea. The United States ranks 18th in the world in broadband access.

"It's absolutely essential to get broadband to more citizens," Bodoff said.