US Patent 7934577 Ignition interlock breathalyzer

The invention relates to an improvement in a breath alcohol test devices includes within the handheld unit containing a fuel cell, a miniaturized self calibrating test device thereby avoiding the need for 30, 60 and 90 day calibration testing. It also relates to various tamper or circumvention improvements that may be used alone or in combination with the self calibration improvement, including cameras to record a driver providing a breath sample and to verify the location of the driver within a vehicle.