Patent ID: 8160694

Claim:
Electrical medical equipment, including; a user operable primary adjustment mechanism containing two or fewer user-adjustable elements, a controller adapted to control and alter at least one output parameter of said equipment, said controller connected and responding to input from said primary adjustment mechanism to alter said output parameter, said primary adjustment mechanism having at least four conditions; a first condition which the mechanism returns to without user input, a second condition, following manipulation of one of said elements from said first condition, a third condition, following manipulation of one of said elements from said first condition, and a fourth condition following manipulation of the same said element manipulated to achieve said third condition to another position, wherein in each said condition said mechanism provides a distinct output as input to said controller, said controller responding to said input by: maintaining said output parameter at a previous level while said input indicates said mechanism is in said first condition, incrementing or gradually increasing the prevailing level of said output parameter while said input indicates said mechanism is in said second condition, decrementing or gradually decreasing the prevailing level of said output parameter while said input indicates said mechanism is in said third condition, and setting the level of said output parameter to zero when said input indicates said mechanism is in said fourth condition.