Click in the Eyewitness News story window above to watch Denise Dador's report.
In the movie "Untraceable," a similar theme, monitoring people verges on stalking. But in reality there is a helpful use for tracking people.
Tracking people down can greatly reduce waiting times in hospitals and doctor's offices.
Dr. Randy Sadd heads pre-operative services at White Memorial Hospital in East L.A. and he says the Tagnos system is the way of the future.
"We have seen significant gains already in terms of the ability to do more procedures in a given time," explains Dr. Sadd.
Here's how the Tagnos system works: Maria Hernandez arrives to get a CAT scan. The transmitter on her wrist sends ultrasound signals to the tracking devices on the ceilings. As soon as she registers she shows up in the computer. The program tells nurses and doctors just how long she's been waiting.
"The patient is automatically followed through each one of these steps," explains Dr. Sadd.
At each point in the process, staffers tell her exactly how long she has left to wait.
"I feel that the experience has been good because the communication has been there," says patient Maria Hernandez.
Creators of the tracking system say soon friends and family will be able to log on to their computer from home, and check check on the progress of their loved one. And the transmitter can also track down hard to find equipment.
"An example would be a pump or a gurney which is somewhere in a hallway. You need it, but you don't know where it is," says Tagnos representative Girish Kulkarni.
Maria says anything that gets her out of the waiting room faster is a good idea.
"It's excellent and it is a great idea for everyone," says Hernandez.
The Tagnos system is being used in hospitals across the country. Some use it to track ER patients, others use it for patients admitted into hospitals.
Dr. Randy Sadd of White Memorial in L.A. says it's cutting waiting times for procedures like X-rays and CAT scans in half.