This paper deals with the design and the development of an equipment, called DDI, as acronym for Disease Detector, developed for the quantitative analysis of neuromotor diseases. It measures the reaction of a person evaluating in the motion of one finger of the hand the time response, the velocity of phalanxes, the force exerted from the finger against a button. The condition of motion are ballistic motion, controlled motion guided by vision, controlled motion without vision, motion with a virtual reality modelization on the computer screen. The system performs also the requirements for medical applications and with its portability and accordance to European normative for safety and quality, represents a new step towards the possibility of quantitative analysis of the performances of the human hand both of mechanical phenomenon and electromyographic of neuromotor diseases, which provoke a decrease in upper and lower limbs action.