Abstract: A coupler having a releasable compression fitting connects a length of tubing to a ventilator fitting. The compression fitting allows the tubing to be made of economical and re-usable materials that would otherwise be difficult to attach to a ventilator fitting. The coupler may have a conical end that can be directly attached to a ventilator fitting, or it may have a barbed end over which an elastomeric endpiece is attached, which in turn can be attached to a ventilator fitting. The tubing and coupler may be sterilized and re-used.

Abstract: A gas mixing valve has first and second inlet chambers linked to supplies of a first and second gas, and a mixing chamber having a blended gas outlet. The inlet chambers are connected to the mixing chamber via first and second control valves, each valve having a valve seat and valve member with opposing surfaces defining a flow control orifice. Each valve seat and valve member are relatively movable between a closed position in which no flow occurs and a maximum opening position to define a series of orifices of progressively increasing area corresponding to the same geometrical progression. The position of each valve member can be controlled to provide a desired mixing ratio. Each valve seat is provided in a respective piston, and the pistons are tied together to move in response to variations in pressure drop across each piston, in order to vary the orifice size to compensate for changes in flow rate without changing the mixing ratio.

Abstract: A gas mixing valve has first and second inlet chambers linked to supplies of a first and second gas, and a mixing chamber having a blended gas outlet. The inlet chambers are connected to the mixing chamber via first and second control valves, each valve having a valve seat and valve member with opposing Surfaces defining a flow control orifice. Each valve seat and valve member are relatively movable between a closed position in which no flow occurs and a maximum opening position to define a series of orifices of progressively increasing area corresponding to the same geometrical progression. The position of each valve member can be controlled to provide a desired mixing ratio. Each valve seat is provided in a respective piston, and the pistons are tied together to move in response to variations in pressure drop across each piston, in order to vary the orifice size to compensate for changes in flow rate without changing the mixing ratio.

Abstract: The breathing of a patient is monitored with a movement sensor, taped to the abdomen of the patient, that produces an output signal indicative of the movement of the diaphragm of the patient. The rate of change of the output signal with time is determined. When the rate of change with time exceeds a preselected value, a ventilation of the lungs of the patient by an external ventilator is initiated.

Abstract: A ventilator is operable to ventilate a patient responsive to a trigger signal. A nasal sensor is affixed to the external surface of the nose of the person. A nasal sensor output signal is produced responsive to the alae nasi reflex or other source of nasal movement of the person, and that nasal sensor output signal is provided to a controller, which in turn produces a trigger signal for the ventilator responsive to the nasal sensor output signal. Other sensor signals can also be measured, and used together with the output of the nasal sensor to provide the most reliable triggering and closest synchronization of the mechanical breathing assistance of the ventilator to the spontaneous breathing efforts of the person.

Abstract: A patient ventilator system provides a controllable flow and volume of a mixed inhalation gas to a patient, and receives exhaled gas from the patient. The ventilator system includes gas flow controllers that mix air and oxygen, and provide the mixture to the patient with a controllable inhalation cycle. The ventilator system monitors the resulting patient pressures and volume of gas exhaled by the patient, as necessary. Compressed air is provided to the gas controller in the event of an absence of an external gas supply by a compressor. A controller permits the user of the ventilator system to control ventilation mode, gas pressure, composition, and flow rate of the mixed gas with a single control knob.

Abstract: Patients are ventilated responsive to a temporary cessation of breathing by monitoring the spontaneous breaths of the patient and providing a series of mechanical breaths to the patient in the event that the spontaneous breaths by the patient cease. The individual breaths of the series are timed such that the rate of the breaths decreases with increasing time, to induce the patient to resume spontaneous breathing. The approach is practiced with a patient ventilator that is operable responsive to a series of commands that trigger the series of mechanical breaths, with the time between breaths gradually increasing.

Abstract: A patient ventilator system provides a controllable flow and volume of a mixed inhalation gas to a patient, and receives exhaled gas from the patient. The ventilator system includes gas flow controllers that mix air and oxygen, and provide the mixture to the patient with a controllable inhalation cycle. The ventilator system monitors the resulting patient pressures and volume of gas exhaled by the patient, as necessary. Compressed air is provided to the gas controller in the event of an absence of an external gas supply by a compressor. A controller permits the user of the ventilator system to control ventilation mode, gas pressure, composition, and flow rate of the mixed gas with a single control knob.

Abstract: An exhalation system for connection in the exhalation path of a ventilator for assisting a patient's breathing includes a heated bacteria filter for heating exhaled gas passing through it to a temperature high enough to substantially avoid condensation in the filter. A connecting passageway on the downstream side of the filter for connection to a monitoring device is also heated along at least part of its length to add additional heat to the gas passing through it so that condensation in the connecting passageway and monitoring device is substantially avoided.