Abstract: A lung ventilator is provided that reduces the number of mechanical components and is able to rapidly adjust to provide a selected volume of air or other gas for delivery to a patient's lungs. The ventilator includes a brushless-type DC electric motor having a number of coils that are energized in a predetermined manner to cause reciprocating movement of a piston within a cylinder. The retracted end position of the piston in a cylinder is used to define the volume of air that is to be received by the patient. Three Hall sensors are connected to the motor at predetermined locations and sense the position of the rotor as it rotates due to the energization of the coils. Each of the pulsed outputs from the Hall sensors is out-of-phase relative to the other Hall sensor outputs. The six different binary outputs of the Hall sensors are identified so that a ROM is able to provide a predetermined output for each of the identified Hall sensor combinations inputted to the ROM.

Abstract: A piston type air pump, for forced lung ventilation, with a variable length of stroke and a variable timing of inspiratory and expiratory phases. The pump includes a stepless change, variable radius crank arm, controllable during pump operation for changing the volume capacity of the pump. The drive motor is arranged for movement for varying the timing of piston in-movement to the piston out-movement for varying the time ratio of inspiration to expiration.

Abstract: A piston type air pump, for forced lung ventilation, with a variable length of stroke and a variable timing of inspiratory and expiratory phases. The pump includes a stepless change, variable radius crank arm, controllable during pump operation for changing the volume capacity of the pump. The drive motor is arranged for movement for varying the timing of piston in-movement to the piston out-movement for varying the time ratio of inspiration to expiration.

Abstract: A piston type air pump, for forced lung ventilation, with a variable length of stroke and a variable timing of inspiratory and expiratory phases. The pump includes a stepless change, variable radius crank arm, controllable during pump operation for changing the volume capacity of the pump. The drive motor is arranged for movement for varying the timing of piston in-movement to the piston out-movement for varying the time ratio of inspiration to expiration.