Waist packs track ER patients

Emergency room doctors and nurses at Brigham and Women's Hospital are getting some high-tech help watching vital signs and rapidly locating patients in the waiting room.

Under a trial funded by a $3.1 million grant from the National Institutes of Health, the hospital will today begin distributing 10 waist packs to patients that contain sensors, transmitters, and tracking gear. The packs will allow medical staff to constantly monitor patients' heart rates and blood-oxygen levels while they await treatment.

If a patient needs immediate attention -- or collapses in the vicinity of the emergency room -- an ultrasound tracking beacon will instantly give caregivers the patient's exact location. If successful, the units could be commercialized to be used to help handle large numbers of patients in major disasters.

''We wanted some way to monitor patients and track where they were," said Dr. Thomas Stair, a Brigham and Women's emergency physician coordinating the project.

The military already has a similar system, Stair said, and ''we're trying to come up with a civilian system using off-the-shelf technology." Stair is familiar with emergencies involving large numbers of patients. His experience includes a two-week volunteer stint in Louisiana after Hurricane Katrina last year.

The pilot program is a joint project of Brigham and Women's Hospital, Harvard Medical School, and the Massachusetts Institute of Technology's Computer Science and Artificial Intelligence Laboratory.

Patients' vital signs will be picked up by a three-lead electrocardiogram and a finger sensor and fed into a personal digital assistant (PDA), then transmitted to a server that will display the information for nurses to monitor.

An ultrasound transmitter will send location information to receivers in the walls of the emergency room, halls, and restrooms. Ultrasound receivers transmit the signals to a computer that stores information about a patient's movements, according to a program written by MIT scientists.

''This system will tell us heart rhythm, oxygen saturation, and where they are so we can respond better to codes," Stair said.

For the tracking equipment, researchers had to make a choice between more-common radio frequency identification tags -- which are beginning to be introduced in research hospitals around the country to track patients and equipment -- or ultrasound trackers.

They chose ultrasound, which cannot penetrate walls, because it pinpoints a patient or piece of equipment to a particular room, said Dorothy Curtis, an MIT research staffer who worked on the project. Radio frequency identification signals travel through walls and floors, which makes it harder to precisely pinpoint a location, Curtis said.

''This tracking industry is really in its infancy. There's no clear winner in the technology," she said.

The ultrasound units are manufactured by Sonitor Technologies Inc., a Norwegian corporation. Sonitor officials hope that more hospitals will take an interest in ultrasound. ''The advantage over RFID is the accuracy," said Sonitor's chief executive Terry Aasen.

Christopher Rowland can be reached at crowland@globe.com.