Abstract: A high-frequency oscillator ventilator has a first gas conduit with an opening for gas connection with a patient's airways and a bias gas flow inlet and a bias flow outlet disposed to define therebetween a flow path for a bias gas within the first conduit. An oscillator operable to alternately introduce a volume of additional gas from a source into, and to withdraw at least the same volume of gas from, the first gas conduit, thereby inducing pressure oscillations in gas within the first conduit to move gas along a path intersecting the flow path for a bias gas alternately into and out of the opening at a predetermined high-frequency dependent on the output of a control signal generator.

Abstract: A patient ventilator system has a high-frequency oscillation ventilator connectable to a patient circuit and operable to induce oscillations within gas in the circuit at a predetermined high-frequency and a gas supply connectable to the patient circuit for supplying breathing gas thereto. A detection device is also included within the ventilator system and is adapted to monitor during the operation of the high-frequency oscillator ventilator, gas pressure and/or gas flow to detect a variation therein not derived from the induced high-frequency oscillations and to output a trigger signal dependent on the detected variation indicating a spontaneous breathing effort. The gas supply is operable on receipt of the trigger signal to supply breathing gas into the circuit at a level to assist the spontaneous breathing effort.

Abstract: A high frequency oscillator (HFO) ventilator has an oscillator unit for alternately supplying a volume of gas (“oscillator volume”) to and removing the oscillator volume from a proximal end of a gas conduit at a predetermined high frequency. The gas conduit has a proximal end connectable to the oscillator unit and a distal end connectable with the patient's airways. Located between the proximal end and the distal end is an inlet for receiving a continuous flow of a bias gas from a supply, and an outlet. The ventilator further has a flow controller adapted to apportion, between the distal end of the conduit and the outlet, the volume of gas supplied by the oscillator unit to establish a predetermined inspiration tidal volume for delivery to the patient's airways independent of the oscillator volume.

Abstract: A high-frequency oscillator (HFO) ventilator has a gas conduit with an opening for gas connection with a patient's airways and a bias gas flow inlet and outlet disposed to define therebetween a bias gas flow-path within the conduit. An oscillator is operable to induce pressure oscillations in gas within the conduit to move a volume of gas (“tidal volume”) along a respiration flow-path, intersecting the bias gas flow-path, alternately in to and out of the opening at a predetermined high-frequency to provide, respectively, an inspiration phase and an expiration phase of a breathing cycle. The HFO ventilator further has an extraction device operable during the breathing cycle, and preferably in timed relation with the operation of the oscillator, to withdraw an additional amount of gas from the respiration flow-path.

Abstract: In a method and arrangement for evaluating effective flow resistance of a patient breathing circuit connected to a mechanical breathing assist device, a flow controller is operable to temporarily introduce an occlusion to the gas flow within the breathing circuit at a time after the end of an inspiration phase of a breathing cycle provided by the breathing assist device. A sensor unit 34 has a flow sensor for measuring gas flow within the circuit and a pressure sensor for measuring gas pressures within the circuit. An evaluating unit receives measurements from the sensor unit, to determine for a measured gas flow a value of a pressure drop within the breathing circuit after the introduction of the occlusion, and establishes a relationship between the calculated pressure drop and the measured gas flow, such as based on the known Blasius formula.

Abstract: in a method and arrangement for evaluating effective flow resistance of a patient breathing circuit connected to a mechanical breathing assist device, a flow controller is operable to temporarily introduce an occlusion to the gas flow within the breathing circuit at a time after the end of an inspiration phase of a breathing cycle provided by the breathing assist device. A sensor unit 34 has a flow sensor for measuring gas flow within the circuit and a pressure sensor for measuring gas pressures within the circuit. An evaluating unit receives measurements from the sensor unit, to determine for a measured gas flow a value of a pressure drop within the breathing circuit after the introduction of the occlusion, and establishes a relationship between the calculated pressure drop and the measured gas flow, such as based on the known Blasius formula.

Abstract: A high frequency oscillator (HFO) ventilator has an oscillator unit for alternately supplying a volume of gas (“oscillator volume”) to and removing the oscillator volume from a proximal end of a gas conduit at a predetermined high frequency. The gas conduit has a proximal end connectable to the oscillator unit and a distal end connectable with the patient's airways. Located between the proximal end and the distal end is an inlet for receiving a continuous flow of a bias gas from a supply, and an outlet. The ventilator further has a flow controller adapted to apportion, between the distal end of the conduit and the outlet, the volume of gas supplied by the oscillator unit to establish a predetermined inspiration tidal volume for delivery to the patient's airways independent of the oscillator volume.

Abstract: A high-frequency oscillator (HFO) ventilator has a gas conduit with an opening for gas connection with a patient's airways and a bias gas flow inlet and outlet disposed to define therebetween a bias gas flow-path within the conduit. An oscillator is operable to induce pressure oscillations in gas within the conduit to move a volume of gas (“tidal volume”) along a respiration flow-path, intersecting the bias gas flow-path, alternately in to and out of the opening at a predetermined high-frequency to provide, respectively, an inspiration phase and an expiration phase of a breathing cycle. The HFO ventilator further has an extraction device operable during the breathing cycle, and preferably in timed relation with the operation of the oscillator, to withdraw an additional amount of gas from the respiration flow-path.

Abstract: A high-frequency oscillator ventilator has a first gas conduit with an opening for gas connection with a patient's airways and a bias gas flow inlet and a bias flow outlet disposed to define therebetween a flow path for a bias gas within the first conduit. An oscillator operable to alternately introduce a volume of additional gas from a source into, and to withdraw at least the same volume of gas from, the first gas conduit, thereby inducing pressure oscillations in gas within the first conduit to move gas along a path intersecting the flow path for a bias gas alternately into and out of the opening at a predetermined high-frequency dependent on the output of a control signal generator.