Abstract: A ventilator that delivers air at different pressures to a patient during inspiratory and expiratory cycles of breathing and that cycles from inspiratory to expiratory operation when the patient's respiratory flow passes a threshold level. The threshold generally increases form the beginning of inspiration to the end of inspiration. The increase can be linear over all or only a proton of the inspiratory cycle, and the threshold can be adjusted so that cycling is prevented during the initial portion of an inspiratory cycle. The minimum and maximum levels may both be functions of peak flow and the threshold may increase as a function of elapsed inspiratory time. The rate at which the threshold increases from a minimum level to a maximum level may be adjustable for individual patient needs and may be determined from previous breaths.

Abstract: A respiratory treatment apparatus and method in which a leak is determined by using an averaging window. The window starts at the present time and extends back in time to a point determined according to a current one of progressively detected phase measures of a first respiratory cycle and a corresponding phase measure attributable to a preceding second respiratory cycle. In another aspect, a jamming index indicates whether the leak is rapidly changing. To the extent that jamming is high, the leak estimate used progressively changes from that using sliding breath-window averaging to a more robust and faster responding low-pass filter method, and adjustment of ventilatory support based on measures employing estimated respiratory flow is slowed down or stopped.

Abstract: A method and apparatus for determining suitable settings for a servo-ventilator to be used during a treatment period. Respiratory characteristics of a patient are measured during a learning period preceding the treatment period. With these measured characteristics, a target ventilation setting may be calculated by alternative methods. The calculated setting may then be used for enforcing a minimum ventilation during the treatment period where ventilatory support is provided with a servo-controlled ventilator.

Abstract: A ventilator device delivers ventilatory support to a patient in a back up timed mode when patient respiration is not detected or a spontaneous mode when patient respiration is detected. The timing threshold governing the back-up mode is chosen to deviate from normal expected respiration time for the patient to promote patient initiated ventilation in the spontaneous mode but permit back-up ventilation in the event of apnea. Automated adjustments to the timing threshold during the timed mode are made from the less vigilant timing threshold to a more vigilant threshold at or near a timing of normal expected breathing of the patient. Such adjustments may be made from a minimum to a maximum vigilance timing settings or incrementally there between as a function of time in the timed mode which is preferably the number of delivered machine breaths.

Abstract: A respiratory flow limitation detection device, which can include an airway pressure treatment generator, determines a flow limitation measure 506 based one or more shape indices for detecting partial obstruction and a measure of a patient's ventilation or respiratory duty cycle. The shape indices may be based on function(s) that ascertain the likelihood of the presence of M-shaped breathing patterns and/or chair-shaped breathing patterns. The measure of ventilation may be based on analysis of current and prior tidal volumes to detect a less than normal patient ventilation. The duty cycle measure may be a ratio of current and prior measures of inspiratory time to respiratory cycle time to detect an increase in the patient's inspiratory cycle time relative to the respiratory cycle time. A pressure setting based on the flow limitation may then be used to adjust the treatment pressure to ameliorate the patient's detected flow limitation condition.

Abstract: A respiratory treatment apparatus and method in which a leak is determined by using an averaging window. The window starts at the present time and extends back in time to a point determined according to a current one of progressively detected phase measures of a first respiratory cycle and a corresponding phase measure attributable to a preceding second respiratory cycle. In another aspect, a jamming index indicates whether the leak is rapidly changing. To the extent that jamming is high, the leak estimate used progressively changes from that using sliding breath-window averaging to a more robust and faster responding low-pass filter method, and adjustment of ventilatory support based on measures employing estimated respiratory flow is slowed down or stopped.

Abstract: A ventilator device delivers ventilatory support to a patient in a back up timed mode when patient respiration is not detected or a spontaneous mode when patient respiration is detected. The timing threshold governing the back-up mode is chosen to deviate from normal expected respiration time for the patient to promote patient initiated ventilation in the spontaneous mode but permit back-up ventilation in the event of apnea. Automated adjustments to the timing threshold during the timed mode are made from the less vigilant timing threshold to a more vigilant threshold at or near a timing of normal expected breathing of the patient. Such adjustments may be made from a minimum to a maximum vigilance timing settings or incrementally there between as a function of time in the timed mode which is preferably the number of delivered machine breaths.

Abstract: A respiratory flow limitation detection device, which can include an airway pressure treatment generator, determines a flow limitation measure (506) based one or more shape indices for detecting partial obstruction and a measure of a patient's ventilation or respiratory duty cycle. The shape indices may be based on function(s) that ascertain the likelihood of the presence of M-shaped breathing patterns and/or chair-shaped breathing patterns. The measure of ventilation may be based on analysis of current and prior tidal volumes to detect a less than normal patient ventilation. The duty cycle measure may be a ratio of current and prior measures of inspiratory time to respiratory cycle time to detect an increase in the patient's inspiratory cycle time relative to the respiratory cycle time. A pressure setting based on the flow limitation may then be used to adjust the treatment pressure to ameliorate the patient's detected flow limitation condition.

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: 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: A servoventilator control slowly changes the target ventilation over a period of time, according to a preprogrammed schedule adapted to be set by the physician. Preferably, the target ventilation stays constant at an initial target ventilation for an initial hold time, and then increases at a constant rate until it reaches a final target ventilation, whereupon it stays constant thereafter. If the pressure support level is too high, possibly indicating glottic or upper airway closure, the rate of increase of target ventilation may be lowered or the final target ventilation not reached.

Abstract: A servoventilator control slowly changes the target ventilation over a period of time, according to a preprogrammed schedule adapted to be set by the physician. Preferably, the target ventilation stays constant at an initial target ventilation for an initial hold time, and then increases at a constant rate until it reaches a final target ventilation, whereupon it stays constant thereafter. If the pressure support level is too high, possibly indicating glottic or upper airway closure, the rate of increase of target ventilation may be lowered or the final target ventilation not reached.

Abstract: A ventilator device delivers ventilatory support to a patient in a back up timed mode when patient respiration is not detected or a spontaneous mode when patient respiration is detected. The timing threshold governing the back-up mode is chosen to deviate from normal expected respiration time for the patient to promote patient initiated ventilation in the spontaneous mode but permit back-up ventilation in the event of apnea. Automated adjustments to the timing threshold during the timed mode are made from the less vigilant timing threshold to a more vigilant threshold at or near a timing of normal expected breathing of the patient. Such adjustments may be made from a minimum to a maximum vigilance timing settings or incrementally there between as a function of time in the timed mode which is preferably the number of delivered machine breaths.

Abstract: Methods and apparatus are disclosed for determining the occurrence of a closed or open apnea. Respiratory air flow from a patient is measured to give an air flow signal. The determination of an apnea is performed by applying an oscillatory pressure waveform of known frequency to a patient's airway, calculating a complex quantity representing a patient admittance (12) and comparing its value with ranges (14,16) indicative of open or closed apneas. The method distinguishes open from closed apneas even when the model used to calculate admittance is not based on details of the respiratory apparatus. In addition the patient admittance may be compared with admittance during normal breathing to avoid having to characterize the airway.

Abstract: A ventilator device delivers ventilatory support to a patient in a back up timed mode when patient respiration is not detected or a spontaneous mode when patient respiration is detected. The timing threshold governing the back-up mode is chosen to deviate from normal expected respiration time for the patient to promote patient initiated ventilation in the spontaneous mode but permit back-up ventilation in the event of apnea. Automated adjustments to the timing threshold during the timed mode are made from the less vigilant timing threshold to a more vigilant threshold at or near a timing of normal expected breathing of the patient. Such adjustments may be made from a minimum to a maximum vigilance timing settings or incrementally there between as a function of time in the timed mode which is preferably the number of delivered machine breaths.

Abstract: Methods and apparatus are disclosed for determining the occurrence of a closed or open apnea. Respiratory air flow from a patient is measured to give an air flow signal. The determination of an apnea is performed by applying an oscillatory pressure waveform of known frequency to a patient's airway, calculating a complex quantity representing a patient admittance (12) and comparing its value with ranges (14,16) indicative of open or closed apneas. The method distinguishes open from closed apneas even when the model used to calculate admittance is not based on details of the respiratory apparatus. In addition the patient admittance may be compared with admittance during normal breathing to avoid having to characterize the airway.

Abstract: Disclosed is an apparatus for treating a respiratory disorder, configured to compute a measure of typical recent ventilation such that a rate of adjustment of the measure of typical recent ventilation is reduced as a measure of recent uncompensated leak increases. Also disclosed is an apparatus for treating a respiratory disorder, configured to compute a target ventilation from a product of a measure of typical recent ventilation and a target fraction, wherein the target fraction is dependent on the recent pressure support.

Abstract: A method of operating a CPAP apparatus in which the interface pressure is controlled to rapidly drop at the start of expiration by an expiratory relief pressure (ERP) that is independent of instantaneous respiratory flow, following which the pressure rises to an inspiratory level at or shortly before the end of expiration, or at the onset of an expiratory pause, if any. The ERP is an increasing function of the inspiratory pressure. The expiratory pressure follows a template that is a function of the expected expiration time, the magnitude of the template being equal to the ERP. The current estimated proportion of expiration is determined by comparing the expiration time of the breath in progress to low-pass filtered expiratory durations measured for a number of the preceding breaths.

Abstract: A ventilator that delivers air at different pressures to a patient during inspiratory and expiratory cycles of breathing and that cycles from inspiratory to expiratory operation when the patient's respiratory flow passes a threshold level. The threshold generally increases form the beginning of inspiration to the end of inspiration. The increase can be linear over all or only a proton of the inspiratory cycle, and the threshold can be adjusted so that cycling is prevented during the initial portion of an inspiratory cycle. The minimum and maximum levels may both be functions of peak flow and the threshold may increase as a function of elapsed inspiratory time. The rate at which the threshold increases from a minimum level to a maximum level may be adjustable for individual patient needs and may be determined from previous breaths.

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.