In Frye v. U.S., 54 App. D.C. 46, 293 F. 1013 (D.C. Cir. 1923), the United States Court of Appeals for the District of Columbia Circuit ruled on the admissibility of expert testimony on a "deception test" based on blood pressure, an early form of the lie detector. 293 F. at 1013. The court explained that, in general, when the question involved does not lie within the range of common experience or common knowledge, but requires special experience or special knowledge . . . the opinions of witnesses skilled in that particular science, art, or trade to which the question relates are admissible in evidence. Id. at 1014. The court noted, however, that just when a scientific principle or discovery crosses the line between the experimental and demonstrable stages is difficult to define. Somewhere in this twilight zone the evidential force of the principle must be recognized, and while courts will go a long way in admitting expert testimony deduced from a well-recognized scientific principle or discovery, the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs. Id.