LOS ANGELES — Delisa Miles is through with cowering. For the first time in her long struggle against domestic violence, the mother of three feels as though someone is backing her up.
In her hometown in the Silicon Valley, and in communities across the United States, authorities have begun offering women like Ms. Miles technology to help them feel safe.
There are buttons to summon aid quickly, alarms to warn of approaching danger, computer-generated phone calls to announce that an abuser has posted bail.
No device can protect absolutely, and critics worry that the new technology will give victims a false sense of security. But women like Miles welcome the programs as proof that, at long last, society is willing to try.
"It helps with healing and growing stronger," Miles said. "It helps with taking control."
The potential market for such high-tech security is huge: The FBI estimates that in the US a woman is beaten by a spouse or lover every 9 to 12 seconds. "But technology is giving victims the means to step off the tracks," says David Beatty, director of public policy for the National Victim Center.
Ms. Miles, for instance, takes some comfort from a pendant that she can press if her ex-boyfriend tries to break into her house. Donated by an alarm company, the pendant will summon police at a touch. Other victims carry free cellular phones distributed by law enforcement and programmed to dial only 911.
TOOLS also include an automated notification system known as VINE that alerts women when their batterers walk free from jail. The system - already installed in 340 communities in 20 states - calls the victim every two hours until she answers and punches in a code to prove she has heard the message.
Another electronic surveillance device, being tested in Florida and Pennsylvania, warns a woman if her abuser invades "hot zones" around her home or office. It builds on technology often used with probationers: The offender wears a bracelet that transmits his location to law enforcement. If he enters a forbidden zone - or cuts off the bracelet - he triggers a computer that dials the victim's phone or pager and alerts police.
But the technology has limitations. The alarm pendants, for example, work only in an individual's home or yard. As for VINE, Miles complained that it notified her of her ex-boyfriend's release from jail nearly 10 hours after he walked free - and then, with a phone call at 2:30 a.m.
Despite such glitches, victims and their advocates welcome the devices - as much for the message they send as for the results they get. At last, they say, they are being taken seriously, by officers who respond to 911 calls, by politicians who fund the high-tech programs, and by corporate bigwigs who donate supplies.