Method and apparatus for oral flow therapy

Abstract

A therapy system configured to wash out or flush out the oral and/or nasal cavity to reduce the effective dead space and reduce the work of breathing. The system may displace the expired air in the oral and/or nasal cavity with atmospheric air, or air with altered concentrations, for example, increased humidity, or oxygen levels. A sealed oral interface is provided to the mouth of a patient to supply a volume of pressurized gas. A control system to synchronize the supply of pressurized gas with the patients respiratory cycle. The supply of respiratory gas may be provided during only a portion of the respiratory cycle.

1 . A method of reducing the work of breathing in a patient, the method comprising:
 sealingly providing a first volume of breathable gas into a rear side of the patient's oral cavity during at least a portion of the patient's expiratory phase of a respiratory cycle to assist with washing out at least a portion of the dead space in the patient's oral and/or nasal cavities.   
     
     
         2 . The method of  claim 1 , wherein the breathable gas is provided continuously throughout the patient's respiratory cycle. 
     
     
         3 . The method of  claim 1 , further comprising the step of detecting the patients respiratory cycle and delivering the first volume of breathable gas during at least a portion of the expiration phase. 
     
     
         4 . The method according to  claim 3 , wherein the first volume of breathable gas is delivered at an end of the expiration phase. 
     
     
         5 . The method of  claim 2 , further comprising an initial step of determining an approximate volume of the patient's oral and/or nasal cavities. 
     
     
         6 . The method of  claim 5 , wherein the volume of the patient's oral and/or nasal cavities is determined based on the patient's height and weight. 
     
     
         7 . The method of  claim 5 , wherein the first volume is equal to or greater than the determined volume. 
     
     
         8 . The method of  claim 1 , wherein the breathable gas is delivered at a constant flow rate. 
     
     
         9 . The method according to  claim 8 , wherein the flow rate is between 5 litres per minute and 20 litres per minute. 
     
     
         10 . The method of  claim 1 , wherein the breathable gas is delivered at a constant pressure. 
     
     
         11 . The method according to  claim 10 , wherein the pressure is less than 4 cmH2O. 
     
     
         12 . The method of  claim 1 , wherein the patient is able to breathe naturally in and out through their nose whilst the volume of breathable gas is delivered. 
     
     
         13 . The method of  claim 1 , wherein the gas is delivered to the oral cavity via a sealed oral interface. 
     
     
         14 . The method of  claim 1  further comprising controlling the breathable gas in accordance with a determined impedance. 
     
     
         15 . The method of  claim 14  wherein the controlling comprises decreasing a pressure of the breathable gas in accordance with a detection of an impedance indicative of an airway blockage. 
     
     
         16 . The method of  claim 1  wherein the first volume of breathable gas is provided with an oral interface comprising first and second release ports configured for gas release at opposing sides of the patient's oral cavity. 
     
     
         17 . The method of  claim 16 , wherein the first and second release ports are configured to reside between the teeth and inner cheek lining during use. 
     
     
         18 . The method of  claim 16  wherein the oral interface includes a teeth engaging portion, the teeth engaging portion adapted to conduct a flow of gas to a rear side of the oral cavity to wash out carbon dioxide in the patient's oral and/or nasal cavities. 
     
     
         19 . The method of  claim 18  wherein the teeth engaging portion of the oral interface is configured to reside between teeth and lips and/or between teeth and a cheek surface within the oral cavity. 
     
     
         20 . The method of  claim 16  wherein a teeth engaging portion of the oral interface is configured as a seal to permit washout of carbon dioxide from the oral cavity through a nasal cavity. 
     
     
         21 . The method of  claim 1  wherein an oral seal permits washout of carbon dioxide from the oral cavity through a nasal cavity.