Stimulator systems and methods for obstructive sleep apnea

Abstract

An electrode lead comprises an electrically insulative cuff body and at least three axially aligned electrode contacts circumferentially disposed along the inner surface of the cuff body when in the furled state. The electrode contacts may be circumferentially disposed around a nerve, and an electrical pulse train may be delivered to the electrode contacts thereby stimulating the nerve to treat obstructive sleep apnea. The electrical pulse train may be one that pre-conditions peripherally located nerve fascicles to not be stimulated, while stimulating centrally located nerve fascicles. A feedback mechanism can be used to titrate electrode contacts and electrical pulse train to the patient. A sensor that is affixed to the case of a neurostimulator can be used to measure physiological artifacts of respiration, and a motion detector can be used to sense tapping of the neurostimulator to toggle the neurostimulator between an ON position and an OFF position.

What is claimed is: 
     
         1 . A neurostimulation system for treating obstructive sleep apnea (OSA) in a patient, comprising:
 an electrode lead carrying at least one electrode contact;   a neurostimulator configured for delivering an electrical pulse train to the at least one electrode contact; and   a feedback mechanism configured for measuring a physiological parameter of the patient indicative of an efficacy of the delivered electrical pulse train in treating the OSA.   
     
     
         2 . The neurostimulation system of  claim 1 , wherein the neurostimulator is further configured for sensing physiological artifacts that are caused by respiration, and delivering the electrical pulse train to the at least one electrode contact in synchronization with a respiratory cycle based on the sensed physiological artifacts. 
     
     
         3 . The neurostimulation system of  claim 2 , wherein the neurostimulator is configured for determining the next projected onset of an inspiratory phase of the respiratory cycle based on the sensed physiological artifacts, and delivering the electrical pulse train to the at least one electrode contact immediately before, at, or right after the next projected onset of the inspiratory phase of the respiratory cycle. 
     
     
         4 . The neurostimulation system of  claim 2 , wherein the neurostimulator is configured for storing data representative of the physiological artifacts sensed by the sensing circuitry. 
     
     
         5 . The neurostimulation system of  claim 1 , wherein the electrical pulse train has an initial, preconditioning current or voltage amplitude and a subsequent higher stimulating current or voltage amplitude. 
     
     
         6 . The neurostimulation system of  claim 1 , further comprising a clinician programmer configured for selecting the at least one electrode contact from the electrode contacts, and transcutaneously communicating with the neurostimulator, and programming the neurostimulator to deliver the electrical pulse train to the selected at least one electrode contact. 
     
     
         7 . The neurostimulation system of  claim 1 , further comprising a patient programmer configured for transcutaneously communicating with the neurostimulator, and toggling the neurostimulator between an OFF position and an ON position, such that in the OFF position, no stimulation is delivered to the at least one electrode contact. 
     
     
         8 . The neurostimulation system of  claim 1 , further comprising an external charger configured for inductively and transcutaneously charging the neurostimulator. 
     
     
         9 . The neurostimulation system of  claim 1 , wherein the feedback mechanism comprises one or more temperature sensors configured for measuring the temperature of inhaled and exhaled air of the patient, one or more carbon dioxide (CO2) sensors configured for measuring a concentration of CO2 in inhaled and exhaled air of the patient, one or more electro-myographic (EMG) sensors configured for measuring the electrical potential generated by the muscle cells of a tongue of the patient, one or more cameras configured for capturing pictures of the airway of the patient, or one or more inertial sensors configured for measuring the movement of the tongue of the patient. 
     
     
         10 . The neurostimulation system of  claim 9 , wherein the feedback mechanism comprises one or more temperature sensors configured for measuring the temperature of inhaled and exhaled air of the patient. 
     
     
         11 . The neurostimulation system of  claim 9 , wherein the feedback mechanism comprises one or more carbon dioxide (CO2) sensors configured for measuring a concentration of CO2 in inhaled and exhaled air of the patient. 
     
     
         12 . The neurostimulation system of  claim 9 , wherein the feedback mechanism comprises one or more electro-myographic (EMG) sensors configured for measuring the electrical potential generated by the muscle cells of a tongue of the patient. 
     
     
         13 . The neurostimulation system of  claim 9 , wherein the feedback mechanism comprises one or more cameras configured for capturing pictures of the airway of the patient. 
     
     
         14 . The neurostimulation system of  claim 9 , wherein the feedback mechanism comprises one or more inertial sensors configured for measuring the movement of the tongue of the patient. 
     
     
         15 . The neurostimulation system of  claim 1 , further comprising a clinician programmer configured for computing a score of the at least one electrode based on the measured physiological parameter. 
     
     
         16 . The neurostimulation system of  claim 15 , wherein the clinician programmer is configured for determining the efficiency of each inspiration phase in the respiratory cycle based on the measured physiological parameter, and computing the score based on the determined efficiency of each inspiration phase in the respiratory cycle. 
     
     
         17 . The neurostimulation system of  claim 15 , wherein the feedback mechanism comprises one or more temperature sensors, the measured physiological parameter is a peak-to-peak difference in temperature of inhaled and exhaled air of the patient, the clinician programmer determines the efficiency of each inspiration phase in the respiratory cycle based on the measured physiological parameter, and computes the score based on the determined efficiency of each inspiration phase in the respiratory cycle. 
     
     
         18 . The neurostimulation system of  claim 15 , wherein the feedback mechanism comprises one or more carbon dioxide (CO2) sensors, the measured physiological parameter is a peak-to-peak difference in the concentration of CO2 in inhaled and exhaled air of the patient, the clinician programmer determines the efficiency of each inspiration phase in the respiratory cycle based on the measured physiological parameter, and computes the score based on the determined efficiency of each inspiration phase in the respiratory cycle. 
     
     
         19 . The neurostimulation system of  claim 15 , wherein the feedback mechanism comprises one or more electro-myographic (EMG) sensors, the measured physiological parameter is an electrical potential generated by the muscle cells of a tongue of the patient, and the clinician programmer determines the extent to which one or more tongue protusor muscles are activated based on the measured physiological parameter, and computes the score based on the determined extent to which the one or more tongue protrusor muscles are activated. 
     
     
         20 . The neurostimulation system of  claim 15 , wherein the feedback mechanism comprises one or more cameras, the physiological parameter is a picture of the airway of the patient, clinician programmer determines the extent to which the airway of the patient is obstructed based on the measured physiological parameter, and computes the score based on the determined extent to which the airway of the patient is obstructed. 
     
     
         21 . The neurostimulation system of  claim 15 , wherein the feedback mechanism comprises one or more inertial sensors, the measured physiological parameter comprises is the movement of the tongue of the patient, the clinician programmer determines the extent to which the tongue of the patient protrudes based on the measured physiological parameter, and computes the score based on the determined extent to which the tongue of the patient protrudes.