(Corvallis, OR) -- Researchers at Oregon State University's College of Engineering say they've developed a sensor system for quickly testing saliva to see if epilepsy patients have the correct level of anti-epileptic medication in their system. The standard way of measuring that uses a time-consuming blood test. Scientists say with more refinement, the hand held device will allow patients to monitor medicine levels at home, reducing the chances of seizures from too little medication and toxic side effects from too much. Roughly three-and-a-half million Americans suffer from epilepsy.