A smart brake system for safety at movement on a slope, includes: a multi-brake which comprises a deceleration brake for working while moving on a descending slope and a ratchet brake for working while moving on an ascending slope; a brake controller which selectively controls one of the deceleration brake and the ratchet brake to work as buoyancy of fluid is varied depending on the movement on the descending or the ascending slope.

A medical chair includes a base, a seat, and a leg rest pivotally mounted relative to the seat and adapted to move between an extended position and a retracted position. The chair further includes a first actuator for tilting the seat with respect to the base, a second actuator for lifting the seat with respect to the base, and a leg rest actuator adapted to move the leg rest. The chair also includes a controller adapted to control the first and second actuators to move the seat between a first position and a second position such that the seat is both lifted and tilted at the same time as the seat moves from the first position to the second position, and wherein the controller is adapted to control the leg rest actuator such that the leg rest maintains a substantially constant orientation with respect to the floor.

A medical chair includes a seat supported by a base and actuators adapted to both tilt and lift the seat with respect to the base. A controller controls the actuators to both lift and tilt the seat as the seat moves from the sitting position to the standing position. The movement from the sitting position to the standing position assists in the egress of an occupant from the chair, while the movement from the standing position to the sitting position assists in the ingress of an occupant to the chair. A backrest on the chair remains substantially vertically oriented during movement between the sitting and standing position so as to provide more comfort to the occupant during the sit-to-stand or stand-to-sit movement. The backrest also moves in a manner that generally keeps the occupant's torso vertically aligned with his or her hips during this movement.

There are provided a rear wheel rotatably provided in a body, a seat disposed on a top surface side of the body, a seat link mechanism by which the seat is supported to be movable up and down between a raised position and a lowered position on the top surface side of the body, and a brake mechanism which inhibits the rear wheel from rotating in interlock with the seat link mechanism, when the seat is raised from the lowered position to the raised position.