Electric surgical instruments can be a boon to patients and doctors. But many need to be sterilized, often by autoclaving, which can force water in through the rubber seals on the controls, ruining the instrument. To solve this problem, engineers at Servometer, Cedar Grove, N.J., (www.servometer.com) designed a "thumbtack-within a-bellows" pushbutton. It has a control button shaped like a tack welded on top of metal bellows. The bottom of the bellows is fastened and sealed to the body of the handpiece which holds the controls. The button has an actuator pin underneath it. When the surgeon pushes the ...