Hospitals Steal Tactic From Stores : Technology: To stop infant kidnapings, some medical centers turn to sensitized bracelets, tape woven into diapers and doorway sensors.

The same electronic security that trips an alarm to catch shoplifters has been adopted by some hospitals to thwart abductions of newborns.

Sensitized bracelets and tape woven into diapers as well as doorway sensors are among the devices installed to prevent what is admittedly a small number of infant kidnapings.

St. Francis Hospital and Medical Center here quietly introduced electronic surveillance to its maternity and neonatal units after a woman sneaked in and took a 16-hour-old infant two years ago.

Hartford Hospital is installing a system, a spokesman said, and Danbury, Conn., Hospital put in similar measures two years ago.

Although such gadgets have been used primarily to foil thefts from libraries and record and clothing stores, “it was a natural evolution” to apply them to hospitals, said Sam Shirley of Sensormatic Electronic Corp., a maker of electronic surveillance devices for retailers, nuclear power plants and those needing to guard computerized information systems.

Danbury Hospital is among Sensormatic’s clients, Shirley said.

Bruce K. Smock, a researcher for the International Assn. for Hospital Security, based near Chicago, said the technology has been available for about three years.

Danbury Hospital installed its system not because of an incident there but as a precaution, spokesman John Morgan said. Hartford and St. Francis hospitals confirmed that they have electronic surveillance in their newborn units but declined to discuss the operation.

It is possible for a savvy shoplifter to defeat some retail systems, which depend on magnetic and microwave methods, Shirley said.

But although a retailer might be willing to accept a 10% failure rate, a hospital obviously cannot, he added.

To address that need, his company, based in Deerfield Beach, Fla., developed a combined acoustic and magnetic system that he said is more effective.

Tags in infant bracelets or diapers are tuned during manufacture to a specific frequency. When the tag passes through a gate, a transmitter beaming that frequency causes the tag to vibrate harmlessly, tripping the alarm, Shirley said.

Unlike systems in retail stores that work only in narrow doorways, the field of detection is as wide as 8 feet, well suited to the larger doorways in hospitals, he said. Backup surveillance techniques may also be in place.

An additional challenge, Smock said, “is designing something small enough for an infant. A high percentage of newborns are preemies (born prematurely)--you can hold one in your hand--so some hospitals have had to adapt the devices themselves.”

Smock said he has kept an unofficial count of 79 child abductions from U.S. hospitals since 1983; 13 of those were in 1989, the latest year for which he had figures.

He said he believes the actual numbers are higher because hospitals have been unwilling to share information with him.

Smock called the hospital kidnaping figures “very minute” in comparison with child abductions generally. An FBI spokesman in Washington said the bureau was unable to provide national figures on abductions.

Smock said that of the 79 abductions he has tracked, all but four infants were later recovered, most within hours of their abduction.

All 79 cases involved a female abductor, he said, although boyfriends and spouses sometimes helped.

A typical abductor profile, Smock said, is a woman “under a lot of pressure to have another child.” Abductors tend to cluster in two age groups, from 16 to 21 and from their mid-30s to early 40s, he said.

Shirley said the crimes are usually easily solved, in part because the criminal has no prior record and because the woman is almost always “not too bright,” he said.

Shirley said Sensormatic is marketing the security gadgets directly to hospitals and to the manufacturers of diapers.