Electric contacts are mounted on the support block of the Machine, where the hand is situated. These contacts are activated as soon as the first "nervous sweat" appears that turns the skin into a conductor. Subsequently the computer becomes disturbed by the electric current that is now transmitted via the skin.
This has two effects: on the one hand, sounds are generated by the closure of the contacts (circuit bending) that can either be interpreted as warning or act as an additional source of stress. On the other hand, they can have an effect on the position of the knife which is controlled by the computer and thereby hurt the potential perpetrator of the disturbance.