Patent ID: 7614699

Claim:
A wheelchair supported by a surface, comprising: a base; a seat pivotally connected to the base for at least two degrees of rotational freedom of movement of the seat with respect to the base, the seat having a bottom and a backrest and resting atop the base with the bottom substantially parallel to the surface when in a reference position; a 3-axis accelerometer connected to the seat, for determining position of the seat with respect to the reference position; a load sensor connected to the seat, for sensing force against the seat; an actuator connected to the base and the seat, the actuator capable of rotating the seat position in the at least two degrees of rotational freedom of movement of the seat with respect to the reference position; a powered controller connected to the actuator, and communicatively connected to the 3-axis accelerometer and the load sensor, the powered controller, in response to the load sensor and the 3-axis accelerometer, activates the actuator varying position of the seat with respect to the reference position via pivot of the seat on the base; and a logic processor of the powered controller, communicatively connected to the 3-axis accelerometer and the load sensor, for invoking the powered controller to activate the actuator, the logic processor responsive to the 3-axis accelerometer determining position of the seat and the load sensor sensing force against the seat, for rotationally varying seat position in respect to the reference position by pivot on the base at intervals.