Systems and methods for treating sleep apnea using neuromodulation

Abstract

Methods and systems for treating sleep apnea using electrical stimulation to a patient's upper and/or lower respiratory nerve or muscle are described. A stimulation regimen can be used to achieve upper airway patency and/or rhythmic air flow in a coordinated fashion during sleep. In some cases, diaphragm activity is monitored to determine whether sufficient upper airway patency and/or rhythmic air flow is achieved and maintained. The stimulation regimen may be adjusted based on the diaphragm activity. In some cases, the system includes modularized components so that the components can be customized to an individual's needs.

What is claimed is: 
     
         1 . A method of treating a patient's sleep apnea symptoms, the method comprising:
 screening the patient for an ability to overcome central apnea symptoms using a percutaneous trial neuromodulation system to repeatedly stimulate one or both of a phrenic nerve and a diaphragm, or increase a stimulus intensity applied to one or both of the phrenic nerve and the diaphragm, in accordance with a rhythmic air flow when a diaphragm electromyographic (EMG) activity is below a first threshold, wherein screening the patient comprises determining whether the patient has underlying obstructive apnea symptoms; and   configuring an implantable neuromodulation system to apply a stimulation regimen based on results from the screening using the percutaneous trial neuromodulation system.   
     
     
         2 . The method of  claim 1 , wherein determining whether the patient has underlying obstructive apnea symptoms comprises applying a central apnea stimulation regimen to treat the central apnea symptoms while monitoring the patient for the presence of obstructive apnea symptoms. 
     
     
         3 . The method of  claim 1 , wherein screening the patient comprises determining that the patient is able to tolerate a stimulation regimen that reduces the central apnea symptoms and/or the obstructive apnea symptoms. 
     
     
         4 . The method of  claim 1 , further comprising implanting the implantable neuromodulation system in the patient. 
     
     
         5 . The method of  claim 1 , wherein screening the patient comprises placing temporary electrodes on the diaphragm of the patient. 
     
     
         6 . The method of  claim 5 , wherein the temporary electrodes are used to sense EMG activity that indicates a presence of central apnea symptoms, and to stimulate the diaphragm to treat the central apnea symptoms. 
     
     
         7 . The method of  claim 6 , wherein the sensed EMG activity is logged as data in the percutaneous trial neuromodulation system, wherein the logged data is accessible for evaluation for configuring the implantable neuromodulation system. 
     
     
         8 . The method of  claim 6 , wherein stimulation parameters for stimulating the diaphragm are titrated to determine if effective stimulation can be tolerated by the patient and overcome central apnea symptoms of the patient. 
     
     
         9 . The method of  claim 5 , wherein additional sensors are used to detect the presence of obstructive apnea symptoms underlying treated central apneas. 
     
     
         10 . The method of  claim 9 , wherein one or more respiratory inductance plethysmography belts is used to determine the presence of obstructive apnea symptoms. 
     
     
         11 . The method of  claim 9 , wherein one or more oxygen sensors is used to determine the presence of obstructive apnea symptoms. 
     
     
         12 . The method of  claim 9 , wherein a polysomnogram system is used to determine the presence of obstructive apnea symptoms. 
     
     
         13 . A system for screening for sleep apnea, comprising:
 one or more controllers;   one or more electrodes operably coupled to the one or more controllers and arranged to stimulate a phrenic nerve and a diaphragm of a patient;   one or more sensing electrodes arranged to sense a diaphragm electromyographic (EMG) activity of the diaphragm of the patient; and   a processor arranged to cause the one or more controllers, via the one or more electrodes to:
 (a) repeatedly stimulate one or both of the phrenic nerve and the diaphragm, or increasing a stimulus intensity applied to one or both of the phrenic nerve and the diaphragm, in accordance with a rhythmic air flow when the EMG activity is below a first threshold; and 
 (b) sense when the EMG activity is above a second threshold. 
   
     
     
         14 . The system of  claim 13 , further comprising a memory configured to store EMG activity data. 
     
     
         15 . The system of  claim 13 , wherein the system comprises additional sensors to determine a presence of obstructive apnea symptoms during stimulation applied for treatment of a central sleep apnea. 
     
     
         16 . The system of  claim 15 , wherein the system also records obstructive apnea symptoms during periods when stimulation is not being applied. 
     
     
         17 . The system of  claim 13 , wherein the first threshold is a central sleep apnea/hypopnea (CSA) threshold. 
     
     
         18 . The system of  claim 13 , wherein the second threshold is an obstructive sleep apnea/hypopnea (OSA) threshold.