How can a person truly know that a lie detector test shows accuracy?

The human body is extraordinary and there are still questions that medical science can't even answer. We are living in a time where computers are doing the work of men. Yes, the fact is that even technology can be inconclusive in not given the right answers. Also, lie detector tests can be altered and be tampered with to fit a persons’ agenda. On any test a person is nervous, agitated, maybe happy, ecstatic and feeling reassured that the outcome is a plus. These emotions and feelings can be picked up as anything and be determined as something else. The device is picking up information in the nervous system to show multitudes of emotions that do not comply with the questions, creating the body gestures of a person to be tense. Now, the person that is administering the test gives out specified questions presented in such a matter to be disguised as multiple choice, this can be very tricky and absolutely wrong. Quite naturally any test that is being given causes a person to be frustrated and nervous because that person wants a positive answer. If the examiner words the question in a way to be confusing, then this will reassure the examiner that he or she is justified in making the person a wrong individual. When taking test, smoking, eating and drinking are not allowed for the examiner and patient when dealing with something as important as this.