Method and apparatus to detect and monitor the frequency of obstructive sleep apnea

Abstract

The present invention provides a method and apparatus for detecting and monitoring obstructive sleep apnea. The apparatus includes an intracardiac impedance sensor to measure intracardiac impedance, a movement sensor to measure an amount of movement of a patient, and a controller operatively coupled to said intracardiac impedance sensor and said movement sensor, said controller adapted to receive at least one of an intracardiac impedance and the amount of movement of the patient and detect obstructive sleep apnea based upon said intracardiac impedance and said movement.

What is claimed:  
     
         1 . A method of detecting and monitoring obstructive sleep apnea, comprising: 
 measuring an intracardiac impedance to detect a change in the intracardiac impedance;    measuring an amount of movement of a patient; and    determining the presence of obstructive sleep apnea based upon the change in the intracardiac impedance and the movement of the patient.    
     
     
         2 . A method of  claim 1 , wherein measuring the intracardiac impedance further comprises measuring the intracardiac impedance between an intracardiac atrial electrode and an intracardiac ventricular electrode.  
     
     
         3 . A method of  claim 1 , wherein measuring the intracardiac impedance further comprises detecting a decrease in the intracardiac impedance.  
     
     
         4 . A method of  claim 1 , wherein measuring the amount of movement of the patient further comprises detecting a low amount of movement of the patient.  
     
     
         5 . A method of detecting and monitoring obstructive sleep apnea, comprising: 
 measuring the intrathoracic impedance to detect a change in the intrathoracic impedance; and    determining the presence of obstructive sleep apnea based upon the change in the intrathoracic impedance.    
     
     
         6 . A method of  claim 5 , wherein measuring the intrathoracic impedance further comprises measuring the intrathoracic impedance between an endocardial electrode and a pacemaker housing.  
     
     
         7 . A method of  claim 5 , wherein measuring the intrathoracic impedance further comprises detecting a decrease in the intrathoracic impedance.  
     
     
         8 . A method of detecting and monitoring obstructive sleep apnea, comprising: 
 measuring impedance minute ventilation to detect a change in the impedance minute ventilation;    measuring an amount of movement of a patient; and    determining the presence of obstructive sleep apnea based upon the change in the impedance minute ventilation and the movement of the patient.    
     
     
         9 . A method of  claim 8 , wherein measuring impedance minute ventilation further comprises detecting an increase in impedance minute ventilation followed by a decrease in impedance minute ventilation.  
     
     
         10 . A method of  claim 8 , wherein measuring impedance minute ventilation further comprises detecting an immediate increase in impedance minute ventilation followed by a more gradual decrease in impedance minute ventilation.  
     
     
         11 . A method of  claim 8 , wherein measuring the amount of movement of the patient further comprises detecting a low amount of movement of the patient.  
     
     
         12 . A method of detecting and monitoring obstructive sleep apnea, comprising: 
 detecting sinus tachycardia;    measuring an atrial-ventricular conduction to detect a change in the atrial-ventricular conduction; and    determining the presence of obstructive sleep apnea based upon detecting sinus tachycardia and the change in the atrial-ventricular conduction.    
     
     
         13 . A method of  claim 12 , measuring the atrial-ventricular conduction further comprises detecting an increase in the atrial-ventricular conduction.  
     
     
         14 . A medical device for detecting and monitoring obstructive sleep apnea, comprising: 
 means for measuring an intracardiac impedance to detect a change in the intracardiac impedance;    means for measuring an amount of movement of a patient; and    means for determining the presence of obstructive sleep apnea based upon the change in the intracardiac impedance and the movement of the patient.    
     
     
         15 . A medical device for detecting and monitoring obstructive sleep apnea, comprising: 
 means for measuring the intrathoracic impedance to detect a change in the intrathoracic impedance; and    means for determining the presence of obstructive sleep apnea based upon the change in the intrathoracic impedance.    
     
     
         16 . A medical device for detecting and monitoring obstructive sleep apnea, comprising: 
 means for measuring impedance minute ventilation to detect a change in the impedance minute ventilation;    means for measuring an amount of movement of a patient; and    means for determining the presence of obstructive sleep apnea based upon the change in the impedance minute ventilation and the movement of the patient.    
     
     
         17 . A medical device for detecting and monitoring obstructive sleep apnea, comprising: 
 means for detecting sinus tachycardia;    means for measuring an atrial-ventricular conduction to detect a change in the atrial-ventricular conduction;    means for determining the presence of obstructive sleep apnea based upon detecting sinus tachycardia and the change in the atrial-ventricular conduction.    
     
     
         18 . A medical device for detecting and monitoring obstructive sleep apnea, comprising: 
 an intracardiac impedance sensor to measure an intracardiac impedance;    a movement sensor to measure an amount of movement of a patient; and    a controller operatively coupled to said intracardiac impedance sensor and said movement sensor, said controller adapted to receive at least one of an intracardiac impedance and the amount of movement of the patient and detect obstructive sleep apnea based upon said intracardiac impedance and said movement.    
     
     
         19 . The medical device of  claim 18 , wherein the movement sensor further comprises a piezo crystal.  
     
     
         20 . The medical device of  claim 18 , wherein the movement sensor further comprises an accelerometer.  
     
     
         21 . The medical device of  claim 18 , further comprising an intrathoracic impedance sensor operatively coupled to said controller to measure an intrathoracic impedance, said controller adapted to receive the intrathoracic impedance and to detect said obstructive sleep apnea based upon said intrathoraic impedance.  
     
     
         22 . The medical device of  claim 18 , further comprising an electrical sensor operatively coupled to said controller to measure electrical activity in a heart, said controller adapted to receive the electrical activity and to detect said obstructive sleep apnea based upon said electrical activity.  
     
     
         23 . The medical device of  claim 22 , wherein the electrical sensor detects cardiac depolarizations.  
     
     
         24 . The medical device of  claim 22 , wherein the electrical sensor comprises an electrical sensing amplifier and at least one of a cardiac electrode and a subcutaneous electrode.  
     
     
         25 . The medical device of  claim 22 , wherein at least one of the intracardiac impedance sensor, the intrathoracic impedance sensor, the movement sensor, and the electrical sensor is implantable.  
     
     
         26 . The medical device of  claim 18 , further comprising a telemetry interface adapted to facilitate real-time access to the data on the controller.