Yes, 3M manufactures a product called MEMS, which is a breath alcohol device that's located in the home. It's hooked up to external power and a phone line. If there's no phone line available it uses wireless communication.
When the offender is at home he will be randomly required to blow into the device. Most of the offenders are on house arrest, so they're scheduled to be home at certain periods of time anyway. The offender blows into the device, and while he is blowing into the device a picture is taken and the results, along with that picture, are sent to the monitoring centre where the results can be reviewed.
It's a breathalyzer. The results hold up in court, at least in U.S. courts.