Abstract: A headgear (200) for a respiratory mask (202) of a ventilator or CPAP device is provided. The headgear includes a strap portion (204, 206) formed of a substantially inextensible material. The strap portion has formed on one end thereof a connecting structure configured to connect to a mask of the ventilator or CPAP device. One advantage is that the mask will not or at least will be less inclined to lift off the face as mask pressure is increased.

Abstract: CPAP treatment apparatus is disclosed having a controllable flow generator (34, 38, 40) operable to produce breathable gas at a treatment pressure elevated above atmosphere to a patient by a delivery tube (32) coupled to a mask (30) having connection with a patient's airway. A sensor (44, 50, 56, 58) generates a signal representative of patient respiratory flow, that is provided to a controller (54, 62, 64). The controller (54, 62, 64) is operable to determine the occurrence of an apnea from a reduction in respiratory airflow below a threshold, and if an apnea has occurred, to determine the duration of the apnea and to cause the flow generator (34, 38) to increase the treatment pressure. In one preferred form the increase in pressure is zero if the treatment pressure before the apnea exceeds a pressure threshold.

Abstract: A comfortable low-leak mask assembly for use with Non-Invasive Positive Pressure Ventilation (NIPPV) is provided to improve patient compliance and/or treatment. The mask system may include headgear having straps that are substantially inextensible and/or micro-adjustable; and/or a mask and/or cushion that includes various structures to allow enhanced/tailored sealing and/or fit at selected locations on the patient's face.

Abstract: A methodology and apparatus for determining ventilator settings including an end expiratory pressure setting, pressure swing, resistive unloading and target ventilation for delivering ventilatory support based upon generalized patient ventilation characteristics and/or disease classifications. An apparatus may be programmed with the instructions to accomplish the methodology interactively by prompting the user/physician during setup and calculating settings based upon measurements or input responses. Pre-assigned values associated with ventilation characteristics or disease classifications may be combined with a base pressure value or measured values to provide patient customized settings or adjustments to determine pressure levels for the delivery of ventilatory support.

Abstract: Methods and apparatus for detecting the occurrence of a potential or actual overpressure during assisted ventilation are described. A blower (10) supplies pressurized gas to a conduit (12), and in turn to a patient mask (11) for connection with the entrance of a patient's airways. A pressure sensor (17, 18) detects the delivered pressure in the mask (11), which is provided to a controller (16). The controller (16) has operation over the blower (10) by way of a servo (19) and motor (20). The controller (16) determines a relatively longterm average of the pressure signal, and compares it against a threshold value (40). If the threshold value is approached or exceeded, the controller (16) controls the blower (10) and thus the supplied pressure to the patient. The effect of the control can be to limit or reduce the supplied gas pressure. The relatively longterm average can be of the order of minutes, or taken over ten or more breaths.

Abstract: Methods and apparatus for determining the occurrence of an apnea, patency and/or partial obstruction of the airway are disclosed. Respiratory air flow from a patient is measured to give an air flow signal. The determination of an apnea is performed by calculating the variance of the air flow signal over a moving time window and comparing the variance with a threshold value. One determination of partial obstruction of the airway is performed by detecting the inspiratory part of the air flow signal, scaling it to unity duration and area and calculating an index value of the amplitude of the scaled signal over a mid-portion. Alternatively, the index value is a measure of the flatness of the air flow signal over the mid-portion.

Abstract: Methods and apparatus for determining the occurrence of an apnea, patency and/or partial obstruction of the airway are disclosed. Respiratory air flow from a patient is measured to give an air flow signal. The determination of an apnea is performed by calculating the variance of the air flow signal over a moving time window and comparing the variance with a threshold value. One determination of partial obstruction of the airway is performed by detecting the inspiratory part of the air flow signal, scaling it to unity duration and area and calculating an index value of the amplitude of the scaled signal over a mid-portion. Alternatively, the index value is a measure of the flatness of the air flow signal over the mid-portion.

Abstract: A mask assembly includes a mask with an inflatable bladder. The internal pressure of the inflatable bladder can be set to be higher than the delivered therapeutic pressure. The pressure offset may be constant, or it may vary over the range of therapeutic pressures. Thus, the force necessary to maintain a contact seal between the mask and the patient can be reduced, thereby providing a system that is more comfortable to the patient, which increases patient compliance.

Abstract: Methods and apparatus for assessing the condition of and treating patients for heart failure by the delivery of continuous positive airway pressure are disclosed. Treatment of obstruction due to reflex vocal cord closure often experienced by heart failure patients is distinguished from treatment of upper airway obstruction typically associated with Obstructive Sleep Disorder Treatment may also be implemented by delivering synchronized cardiac pressure oscillations superimposed on a respiratory pressure level to provide assistance for the heart. Heart treatment pressure dose indicator may be calculated for prescribing and monitoring the delivery of treatment. The apparatus may also generate data to track heart failure condition that may be indicative of the degree of severity of heart failure based upon breathing patterns to assist in the diagnosis and management of heart failure patients.

Abstract: CPAP treatment apparatus is disclosed having a controllable flow generator (34, 38, 40) operable to produce breathable gas at a treatment pressure elevated above atmosphere to a patient by a delivery tube (32) coupled to a mask (30) having connection with a patient's airway. A sensor (44, 50, 56, 58) generates a signal representative of patient respiratory flow, that is provided to a controller (54, 62, 64). The controller (54, pressure. In one preferred form the increase in pressure is zero if the treatment pressure before the apnea exceeds a pressure threshold. Below the pressure threshold the increase in pressure is an increasing function of the duration of the apnea multiplied by the difference between the pressure threshold and the current treatment pressure.

Abstract: A methodology and apparatus for determining ventilator settings including an end expiratory pressure setting, pressure swing, resistive unloading and target ventilation for delivering ventilatory support based upon generalized patient ventilation characteristics and/or disease classifications. An apparatus may be programmed with the instructions to accomplish the methodology interactively by prompting the user/physician during setup and calculating settings based upon measurements or input responses. Pre-assigned values associated with ventilation characteristics or disease classifications may be combined with a base pressure value or measured values to provide patient customized settings or adjustments to determine pressure levels for the delivery of ventilatory support.

Abstract: A method and CPAP apparatus for automatically adjusting a continuous positive airway treatment pressure delivered to a patient responds in different manners according to the type of breathing problem. If a respiratory event is an apnea at a treatment pressure below a first value, then the treatment pressure is increased in one manner. If the respiratory event is a partial upper airway obstruction at a treatment pressure below a second value, then the treatment pressure is increased in a different manner; where the first pressure value is less than the second pressure value. In particular, obstructive and central apneas are treated differently by the apparatus.

Abstract: A method and apparatus for treating sleep disordered breathing. An arousal index is determined for use in an outer loop of a control algorithm, the arousal index being a measure of the frequency of sleep arousals. The respiratory airflow signal in an inner loop of the control algorithm is monitored to detect an airway obstruction. If the arousal index is high, then the sensitivity of obstruction detection and/or the aggressiveness of the treatment is increased, and if the arousal index is low, then the sensitivity of the obstruction detection and/or the aggressiveness of the treatment is decreased.

Abstract: The invention is a ventilator whose servo-controller adjusts the degree of support by adjusting the profile of the pressure waveform as well as the pressure modulation amplitude. As the servo-controller increases the degree of support by increasing the pressure modulation amplitude, it also generates a progressively more square, and therefore efficient, pressure waveform; when the servo-controller decreases the degree of support by decreasing the pressure modulation amplitude, it also generates a progressively more smooth and therefore comfortable pressure waveform.

Abstract: The invention is a ventilator whose servo-controller adjusts the degree of support by adjusting the profile of the pressure waveform as well as the pressure modulation amplitude. As the servo-controller increases the degree of support by increasing the pressure modulation amplitude, it also generates a progressively more square, and therefore efficient, pressure waveform; when the servo-controller decreases the degree of support by decreasing the pressure modulation amplitude, it also generates a progressively more smooth and therefore comfortable pressure waveform.

Abstract: The apparatus provides for the determination of the instantaneous phase in the respiratory cycle, subject's average respiration rate and the provision of ventilatory assistance. A microprocessor (16) receives an airflow signal from a pressure transducer (18) coupled to a port (17) at a mask (11). The microprocessor (16) controls a servo (19), that in turn controls the fan motor (20) and thus the pressure of air delivered by the blower (10). The blower (10) is coupled to a subject's mask (ii) by a conduit (12). The invention seeks to address the following goals: while the subject is awake and making substantial efforts the delivered assistance should be closely matched in phase with the subject's efforts; the machine should automatically adjust the degree of assistance to maintain at least a specified minimum ventilation without relying on the integrity of the subject's chemoreflexes; and it should continue to work correctly in the presence of large leaks.

Abstract: Methods and apparatus for detecting the occurrence of a potential or actual overpressure during assisted ventilation are described. A blower (10) supplies pressurised gas to a conduit (12), and in turn to a patient mask (11) for connection with the entrance of a patient's airways. A pressure sensor (17, 18) detects the delivered pressure in the mask (11), which is provided to a controller (16). The controller (16) has operation over the blower (10) by way of a servo (19) and motor (20). The controller (16) determines a relatively longterm average of the pressure signal, and compares it against a threshold value (40). If the threshold value is approached or exceeded, the controller (16) controls the blower (10) and thus the supplied pressure to the patient. The effect of the control can be to limit or reduce the supplied gas pressure. The relatively longterm average can be of the order of minutes, or taken over ten or more breaths.

Abstract: The apparatus provides for the determination of the instantaneous phase in the respiratory cycle, subject's average respiration rate and the provision of ventilatory assistance. A microprocessor (16) receives an airflow signal from a pressure transducer (18) coupled to a port (17) at a mask (11). The microprocessor (16) controls a servo (19), that in turn controls the fan motor (20) and thus the pressure of air delivered by the blower (10). The blower (10) is coupled to a subject's mask (ii) by a conduit (12). The invention seeks to address the following goals: while the subject is awake and making substantial efforts the delivered assistance should be closely matched in phase with the subject's efforts; the machine should automatically adjust the degree of assistance to maintain at least a specified minimum ventilation without relying on the integrity of the subject's chemoreflexes; and it should continue to work correctly in the presence of large leaks.

Abstract: Method and apparatus for the treatment of cardiac failure, Cheyne Stokes breathing or central sleep apnea are disclosed. A subject is provided with ventilatory support, for example positive pressure ventilatory support using a blower and mask. Respiratory airflow is determined. From the respiratory airflow are derived a measure of instantaneous ventilation (for example half the absolute value of the respiratory airflow) and a measure of longterm average ventilation (for example the instantaneous ventilation low pass filtered with a 100 second time constant). A target ventilation is taken as 95% of the longterm average ventilation. The instantaneous ventilation is fed as the input signal to a clipped integral controller, with the target ventilation as the reference signal. The output of the controller determines the degree of ventilatory support. Clipping is typically to between half and double the degree of support that would do all the respiratory work.

Abstract: A method and apparatus for treating sleep disordered breathing. An arousal index is determined for use in an outer loop of a control algorithm, the arousal index being a measure of the frequency of sleep arousals. The respiratory airflow signal in an inner loop of the control algorithm is monitored to detect an airway obstruction. If the arousal index is high, then the sensitivity of obstruction detection and/or the aggressiveness of the treatment is increased, and if the arousal index is low, then the sensitivity of the obstruction detection and/or the aggressiveness of the treatment is decreased.