It was just a matter of time until scientists developed devices to measure alcohol, marijuana, automobile-driving ability, etc.
The journal of Bioscience Technology reports 4 new devices that the law can monitor your body for drugs, marijuana.
Go to Google and type titles into search box:
"Electronic Skin Patch Measures Blood Alcohol Content."
"Wearable Electronic Patch Detects Blood Alcohol Content Quickly."
"Roadside Breathalyzer Can Detect High Driving."
"Toward A Marijuana Breathalyzer Test."