A powered tool for performing surgical procedures. The tool includes a handpiece
in which a power generating unit is housed. A control member is mounted to the
handpiece. The control member is mounted to the handpiece so that the orientation
of the control member can be selectively set relative to the point to which it
is mounted to the handpiece and so it can move relative to a reference point on
the handpiece. A control module monitors the orientation of the control member
and its position relative to the reference point. Based on the control member orientation
and position, the control module generates signals to regulate the operation of
the power generating unit. When the power generating unit is a motor, the control
module generates signals to ensure that the maximum speed at which the motor can
be driven is less than the no load speed.