System and Method for Improved Treatment of Sleeping Disorders using Therapeutic Positive Airway Pressure

Abstract

Described is a method and system providing therapeutic positive airway pressure to a particular area of patient's airways. The system may include a flow generator and a processing arrangement. The flow generator supplies an airflow to an airway of the patient. The processing arrangement is connected to the flow generator to control a supply pressure at which the airflow is generated by the flow generator. The processing arrangement continuously adjusts the supply pressure to maintain a pressure in a predetermined portion of the patient's airway substantially constant. The predetermined portion of the patient's airway includes a collapsible portion of an upper airway of the patient. The processing arrangement also controls the supply pressure to maintain the pressure in the collapsible portion of the patient's airway at a value at least as great as a tissue pressure below which the collapsible portion collapses.

Description

BACKGROUND[0001]Obstructive sleep apnea / hypopnea syndrome (OSAHS) is a well recognized disorder which may affect as much as 1-5% of the adult population. OSAHS is one of the most common causes of excessive daytime somnolence. OSAHS is most frequent in obese males, and it is the single most frequent reason for referral to sleep disorder clinics.[0002]OSAHS is associated with all conditions in which there is anatomic or functional narrowing of the patient's upper airway, and is characterized by an intermittent obstruction of the upper airway occurring during sleep. The obstruction results in a spectrum of respiratory disturbances ranging from the total absence of airflow (apnea) to significant obstruction with or without reduced airflow (hypopnea, episodes of elevated upper airway resistance and snoring), despite continued respiratory efforts. The morbidity of the syndrome arises from hypoxemia, hypercapnia, bradycardia and sleep disruption associated with the respiratory obstruction ...

AI Technical Summary

Problems solved by technology

OSAHS is one of the most common causes of excessive daytime somnolence.

The obstruction results in a spectrum of respiratory disturbances ranging from the total absence of airflow (apnea) to significant obstruction with or without reduced airflow (hypopnea, episodes of elevated upper airway resistance and snoring), despite continued respiratory efforts.

However, it is now well recognized that obstruction of the upper airway during sleep is in part due to the collapsible behavior of the supraglottic segment of the respiratory airway during the negative intraluminal pressure generated by inspiratory effort.

The availability of this non-invasive form of therapy has resulted in extensive publicity for sleep apnea / hypopnea and the appearance of large numbers of patients who previously may have avoided the medical establishment because of the fear of tracheostomy.

However, Bi-level PAP has been shown to have little benefit in obstructive sleep apnea as the second expiratory pressure needs to be set at or near the level that would have been chosen for single pressure CPAP in order to prevent airway collapse.

However, as will be discussed below, patients who do not need assistance in breathing may find it difficult to draw the amount of air they desire as these systems react to their breathing by changing inhalation and exhalation pressures, and thus may not deliver the necessary pressure at the beginning of inspiration predictably.

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