Method and system for applying stimulation in treating sleep disordered breathing

Abstract

A stimulation protocol determination system includes an input module and a selector module. The input module is provided to receive an indication of an upper airway flow limitation via sensed respiratory effort information. The selection module is provided to automatically select, based on the indicated upper airway flow limitation, a stimulation protocol.

1 . A stimulation protocol determination system comprising:
 an input module to receive an indication of an upper airway flow limitation via sensed respiratory effort information, wherein the indicated upper airway flow limitation corresponds to at least a partial obstruction of the upper airway associated with sleep apneas; and   a selection module to automatically select, based on the indicated upper airway flow limitation, a nerve stimulation protocol including at least one of:
 a first protocol to apply nerve stimulation generally synchronous with an expiratory phase of a respiratory cycle; and 
 a second protocol to apply nerve stimulation during both of a portion of an inspiratory phase of the respiratory cycle and a portion of the expiratory phase. 
   
     
     
         2 . (canceled) 
     
     
         3 . The system of  claim 1 , wherein the first protocol is automatically selected when the indicated upper airway flow limitation predominantly coincides with the expiratory phase. 
     
     
         4 . The system of  claim 1 , wherein the second protocol is automatically selected when the indicated upper airway flow limitation predominantly coincides with both of a first portion of the inspiratory phase and a first portion of the expiratory phase but does not predominantly coincide with a second portion of inspiratory phase and with a second portion of the expiratory phase. 
     
     
         5 . The system of  claim 4 , wherein the first portion of the inspiratory phase includes at least an end portion of the inspiratory phase and excludes a beginning portion of the inspiratory phase, and wherein the first portion of the expiratory phase includes at least a beginning portion of the expiratory phase and excludes an end portion of the expiratory phase. 
     
     
         6 - 7 . (canceled) 
     
     
         8 . The system of  claim 5 , wherein the second protocol includes a generally continuous stimulation period applied during at least a portion of at least some respiratory cycles, wherein the generally continuous stimulation period predominantly coincides with the first portion of the inspiratory phase and with the first portion of the expiratory phase, and
 wherein the generally continuous stimulation period includes an initial start point located after a beginning of the inspiratory phase and an initial termination point located prior to an end of the expiratory phase.   
     
     
         9 . The system of  claim 8 , wherein the second protocol includes the application of the generally continuous stimulation period for a set of consecutive respiratory cycles over a first time period and wherein the input module is configured to:
 determine if at least some indications of upper airway flow limitations exceeding a dysfunction threshold are received within the first time period;   maintain or increase a duration of the generally continuous stimulation period if the input module receives the at least some indications during the first time period;   reduce the duration of the generally continuous stimulation period if the input module receives no indications during the first time period.   
     
     
         10 . The system of  claim 9 , wherein the first time period, based on an apnea-hypopnea index, for which an apnea would likely occur in the absence of stimulation. 
     
     
         11 . The system of  claim 9 , wherein reducing the duration includes at least one of:
 decrementally moving the initial start point closer to the end portion of the inspiratory phase for the next set of consecutive respiratory cycles;   decrementally moving the initial termination point closer to the beginning portion of the expiratory phase for the next set of consecutive respiratory cycles.   
     
     
         12 . The system of  claim 8 , wherein a first portion of the generally continuous stimulation period coincides with the first portion of the inspiratory phase and has a duration of at least one of:
 at least one-third of an entirety of the inspiratory phase;   at least one-half of the entirety of the inspiratory phase; and   at least two-thirds of the entirety of the inspiratory phase.   
     
     
         13 . The system of  claim 8 , wherein a second portion of the generally continuous stimulation period coincides with the first portion of the expiratory phase and has a duration of at least one of:
 at least one-third of the entirety of the expiratory phase;   at least one-half of the entirety of the expiratory phase; and   at least two-thirds of the entirety of the expiratory phase.   
     
     
         14 . The system of  claim 5 , wherein the first portion of the inspiratory phase corresponds to at least a majority of the inspiratory phase and the first portion of the expiratory phase corresponds to at least a majority of the expiratory phase. 
     
     
         15 . The system of  claim 14 , wherein the majority of the inspiratory phase comprises at least two-thirds of the inspiratory phase and the majority of the expiratory phase comprises at least two-thirds of the expiratory phase. 
     
     
         16 . The system of  claim 1 , wherein the selection module is configured to automatically select a third protocol to apply stimulation generally synchronous with the inspiratory phase when the flow limitation generally coincides with the inspiratory phase, and wherein the system comprises a respiration sensor to provide the sensed respiratory effort information. 
     
     
         17 . The system of  claim 1 , comprising
 an implantable pulse generator; and   a nerve cuff electrode electrical couplable to the pulse generator to apply a respective one of the first and second stimulation protocols.   
     
     
         18 . The system of  claim 1 , wherein the nerve stimulation protocol is applied to at least the hypoglossal nerve. 
     
     
         19 . (canceled) 
     
     
         20 . A non-transitory computer readable medium for storing machine readable instructions to provide a stimulation protocol determination module comprising:
 an input function to receive an indication of an upper airway flow limitation via sensed respiratory effort information; and   a selection function to automatically select, based on the indicated upper airway flow limitation, a stimulation protocol including at least one of:
 a first protocol to apply stimulation generally synchronous with an expiratory phase of a respiratory cycle; and 
 a second protocol to apply stimulation during a portion of both of an inspiratory phase of the respiratory cycle and the expiratory phase. 
   
     
     
         21 . The system of  claim 1 , comprising:
 a non-volatile memory for storing, and a processor for executing, machine readable instructions to provide the input module and the selection module.   
     
     
         22 . A method of nerve stimulation comprising:
 sensing respiratory effort information to identify an upper airway flow limitation associated with obstructive sleep apneas; and   automatically applying stimulation from an implantable pulse generator through a cuff electrode to an airway-patentcy-related nerve, based on the identified upper airway flow limitation, according to least one of:
 a first protocol to apply stimulation to the nerve generally synchronous with an expiratory phase of a respiratory cycle; and 
 a second protocol to apply stimulation to the nerve during both of a portion of an inspiratory phase of the respiratory cycle and a portion of the expiratory phase. 
   
     
     
         23 . The system of  claim 22 , wherein the automatically applying comprises:
 automatically selecting the first protocol when the indicated upper airway flow limitation predominantly coincides with the expiratory phase; and   automatically selecting the second protocol when the indicated upper airway flow limitation predominantly coincides with both of a first portion of the inspiratory phase and a first portion of the expiratory phase but does not predominantly coincide with a second portion of inspiratory phase and with a second portion of the expiratory phase.   
     
     
         24 . The system of  claim 23 , wherein the first portion of the inspiratory phase includes at least an end portion of the inspiratory phase and excludes a beginning portion of the inspiratory phase, and wherein the first portion of the expiratory phase includes at least a beginning portion of the expiratory phase and excludes an end portion of the expiratory phase. 
     
     
         25 . The system of  claim 24 , wherein automatically applying stimulation via the second protocol includes:
 applying a generally continuous stimulation period during at least a portion of at least some respiratory cycles, wherein the generally continuous stimulation period predominantly coincides with the first portion of the inspiratory phase and with the first portion of the expiratory phase, and   wherein the generally continuous stimulation period includes an initial start point located after a beginning of the inspiratory phase and an initial termination point located prior to an end of the expiratory phase.   
     
     
         26 . The system of  claim 25 , comprising:
 applying the generally continuous stimulation period for a set of consecutive respiratory cycles over a first time period, including:
 determining if at least some indications of upper airway flow limitations exceeding a dysfunction threshold are received within the first time period; 
 maintaining or increasing a duration of the generally continuous stimulation period if the at least some indications are received during the first time period; and 
 reducing the duration of the generally continuous stimulation period if no indications are received during the first time period. 
   
     
     
         27 . The system of  claim 26 , wherein reducing the duration includes at least one of:
 decrementally moving the initial start point closer to the end portion of the inspiratory phase for the next set of consecutive respiratory cycles;   decrementally moving the initial termination point closer to the beginning portion of the expiratory phase for the next set of consecutive respiratory cycles.   
     
     
         28 . The system of  claim 25 , wherein a first portion of the generally continuous stimulation period coincides with the first portion of the inspiratory phase and has a duration of at least one of:
 at least one-third of an entirety of the inspiratory phase;   at least one-half of the entirety of the inspiratory phase; and   at least two-thirds of the entirety of the inspiratory phase.   
     
     
         29 . The system of  claim 25 , wherein a second portion of the generally continuous stimulation period coincides with the first portion of the expiratory phase and has a duration of at least one of:
 at least one-third of the entirety of the expiratory phase;   at least one-half of the entirety of the expiratory phase; and   at least two-thirds of the entirety of the expiratory phase.