A method for evaluating the in vivo presence of a factor that prevents the biological effect of a type I in an individual that is under treatment with type I interferon is described. The system includes a frame adapted for placement on a platform. Therefore, it is possible to solve a problem of monotonous handwriting input in the related art where only the position is input and the handwriting is output with the same thickness. The oscilloscope includes: two comparators, a phase rotator that outputs an oscilloscope clock signal whose phase can be varied relative to that of the recovered clock signal, and an offset circuit that outputs a voltage offset. The count at that time is the control word, which if everything operated instantaneously, would be the control word that would alter the attenuation sufficiently to achieve nominal power. Each aperture has a detector and if the balls are captured in pre-selected apertures, an award is provided to the player.