Systems and methods for strengthening a respiratory muscle

Abstract

This disclosure describes methods and systems for stimulating a respiratory muscle of a patient. The methods herein may include positioning a stimulator adjacent a nerve capable of activating the respiratory muscle; activating the stimulator to cause the respiratory muscle to contract; and ceasing the activation of the stimulator for a period of time. The level and the time of the stimulation may be adjusted for various applications. One or more of the steps in the methods may be repeated. The systems herein may include a stimulator for positioning adjacent a nerve capable of activating the respiratory muscle; a signal generator for providing stimulation energy to the stimulator; a sensor for detecting a response of the respiratory muscle to the stimulation energy; and a controller programmed to control the signal generator for providing stimulation with desired level and time.

We claim: 
     
         1 . A method for stimulating a respiratory muscle of a patient, comprising:
 a. positioning a stimulator adjacent a nerve capable of activating the respiratory muscle;   b. activating the stimulator to cause the respiratory muscle to contract only 100 times or less;   c. ceasing the activation of the stimulator for one or more hours; and   d. repeating steps (b) and (c) at least once.   
     
     
         2 . The method of  claim 1 , further comprising selecting a pre-determined value of a maximum inspiratory pressure of the patient, and repeating steps (b) and (c) until the maximum inspiratory pressure of the patient increases to the pre-determined value. 
     
     
         3 . The method of  claim 2 , wherein the pre-determined value is at least 30 cm H 2 O. 
     
     
         4 . The method of  claim 1 , wherein the nerve is a first nerve, and the respiratory muscle is a first respiratory muscle, and the method further includes carrying out steps (a) through (d) relative to a second nerve and a second respiratory muscle. 
     
     
         5 . The method of  claim 1 , wherein the stimulator includes one or more of transvascular electrodes, transdermal electrodes, subcutaneous electrodes, or electrodes configured to be positioned in contact with the nerve. 
     
     
         6 . The method of  claim 1 , further comprising determining a stimulation threshold, wherein the step of determining includes palpating the respiratory muscle. 
     
     
         7 . The method of  claim 1 , further comprising determining a stimulation threshold, wherein the step of determining includes observing at least one of a pressure data or a volume data from an external respiratory support system. 
     
     
         8 . The method of  claim 1 , wherein the patient initiates at least one respiratory muscle contraction of step (b). 
     
     
         9 . The method of  claim 1 , further comprising using a mechanical ventilator to provide respiratory support to the patient during at least a portion of step (b). 
     
     
         10 . A method for stimulating a respiratory muscle of a patient, comprising:
 a. positioning a stimulator adjacent a nerve capable of activating the respiratory muscle;   b. first activating the stimulator to cause the respiratory muscle to contract only 100 times or less;   c. ceasing the first activation of the stimulator for at least 30 seconds;   d. after step (c), second activating the stimulator to cause the respiratory muscle to contract only 100 times or less;   e. ceasing the second activation of the stimulator for one or more hours; and   f. repeating steps (b) through (e) at least once.   
     
     
         11 . The method of  claim 10 , wherein the nerve is at least one of a phrenic nerve or a vagus nerve. 
     
     
         12 . The method of  claim 10 , wherein the nerve is a first nerve, the respiratory muscle is a first respiratory muscle, and the stimulator includes a first set of electrodes positioned adjacent the first nerve and a second set of electrodes positioned adjacent a second nerve capable of activating either the first respiratory muscle or a second respiratory muscle, and the method further comprises:
 g. first activating the second set of electrodes to cause the first or second respiratory muscle to contract only 100 times or less;   h. ceasing the first activation of the second set of electrodes for at least 30 seconds;   i. after step (h), second activating the second set of electrodes to cause the first or second respiratory muscle to contract only 100 times or less;   j. ceasing the second activation of the second set of electrodes for one or more hours; and   k. repeating steps (g)-(j) at least once.   
     
     
         13 . The method of  claim 12 , wherein steps (b) and (g) occur at a same time. 
     
     
         14 . The method of  claim 10 , further comprising:
 sensing a contraction of the respiratory muscle; and   adjusting at least one stimulation parameter to achieve a desired contraction of the respiratory muscle.   
     
     
         15 . The method of  claim 14 , wherein the steps of sensing and adjusting are carried out automatically by a controller. 
     
     
         16 . The method of  claim 15 , wherein the controller is implanted in the patient. 
     
     
         17 . The method of  claim 10 , wherein step (b) includes 100 or less stimulations corresponding to the 100 or less contractions of the respiratory muscle, and step (b) includes adjusting at least one stimulation parameter between a first stimulation of the 100 or less stimulations and a second stimulation of the 100 or less stimulations. 
     
     
         18 . A method for stimulating a respiratory muscle of a patient, comprising:
 a. positioning a stimulator adjacent a nerve capable of activating a respiratory muscle; and   b. activating the stimulator to cause the respiratory muscle to contract for no more than 20% of the breaths taken by, or delivered to, the patient in a 24-hour period.   
     
     
         19 . The method of  claim 18 , wherein step (b) includes activating the stimulator to cause the respiratory muscle to contract for no more than 10% of the breaths taken by, or delivered to, the patient in the 24-hour period. 
     
     
         20 . The method of  claim 18 , further comprising:
 providing external respiratory support for at least 60% of the patient's breaths in the 24-hour period; and   subsequent to step (b), at least one of reducing a pressure provided by the external respiratory support or reducing a percentage of breaths assisted by the external respiratory support.   
     
     
         21 . The method of  claim 20 , wherein the external respiratory support includes at least one of mechanical ventilation, BiPAP, CPAP, or nasal cannula oxygenation. 
     
     
         22 . The method of  claim 18 , wherein the stimulator includes a plurality of electrodes, and the method further comprises using a controller to automatically select an electrode combination from the plurality of electrodes for stimulating the nerve and causing the respiratory muscle to contract. 
     
     
         23 . The method of  claim 18 , further comprising using a sensor to measure a physiological parameter of the patient, wherein the physiological parameter includes at least one of a breath rate, a heart rate, an ECG, a temperature, a motion, a blood oxygen level, a blood CO 2  level, or an air flow. 
     
     
         24 . A method for stimulating a respiratory muscle of a patient, comprising:
 a. positioning a stimulator adjacent a nerve capable of activating the respiratory muscle;   b. providing external respiratory support to the patient;   c. providing extracorporeal membrane oxygenation to the patient to at least one of remove CO 2  or add oxygen to the patient's blood; and   d. activating the stimulator to cause the respiratory muscle to contract for no more than five cumulative hours in a 24-hour period.   
     
     
         25 . The method of  claim 24 , at least some stimulations during the activation of the stimulator in step (d) occur during inspiration periods of the external respiratory support provided in step (b). 
     
     
         26 . The method of  claim 24 , wherein a first time period between a first pair of consecutive stimulations during the activation of the stimulator in step (d) is different than a second time period between a second pair of consecutive stimulations during the activation of the stimulator in step (d). 
     
     
         27 . The method of  claim 24 , further comprising delivering at least one drug to the patient prior to step (d). 
     
     
         28 . The method of  claim 24 , wherein a plurality of electrodes of the stimulator are positioned within the patient through a percutaneous incision. 
     
     
         29 . The method of  claim 24 , wherein a plurality of electrodes of the stimulator are positioned external to the patient. 
     
     
         30 . The method of  claim 24 , further comprising using a sensor to detect an inflammatory agent. 
     
     
         31 . A method for stimulating a respiratory muscle of a patient, comprising:
 a. positioning a stimulator adjacent a nerve capable of activating the respiratory muscle;   b. providing external respiratory support for at least 90% of the patient's breaths in a 24-hour period;   c. activating the stimulator to cause the respiratory muscle to contract for no more than five cumulative hours in a 24-hour period;   d. repeating steps (b) and (c) for 48 hours; and   e. removing the external respiratory support from the patient.   
     
     
         32 . The method of  claim 31 , further comprising repeating step (c) for at least one day after removing the external respiratory support from the patient. 
     
     
         33 . A method for stimulating a respiratory muscle of a patient, comprising:
 a. positioning a stimulator adjacent a nerve capable of activating the respiratory muscle; and   b. activating the stimulator to cause the respiratory muscle to contract while the patient is breathing for a cumulative duration of 2 hours or less per day.   
     
     
         34 . A system for stimulating a respiratory muscle of a patient, comprising:
 a stimulator for positioning adjacent a nerve capable of activating the respiratory muscle;   a signal generator for providing stimulation energy to the stimulator;   a sensor for detecting a response of the respiratory muscle to the stimulation energy; and   a controller programmed to:
 i. cause the signal generator to provide stimulation energy to the stimulator to cause only 100 or less contractions of the respiratory muscle; and 
 ii. cause the signal generator to provide a period of one hour or more after causing the 100 or less contractions. 
   
     
     
         35 . The system of  claim 34 , wherein the stimulator includes one or more of: nerve stimulation electrodes, endotracheal electrodes, endoesophageal electrodes, intravascular electrodes, transcutaneous electrodes, intracutaneous electrodes, electromagnetic beam electrodes, balloon-type electrodes, basket-type electrodes, umbrella-type electrodes, tape-type electrodes, suction-type electrodes, screw-type electrodes, barb-type electrodes, bipolar electrodes, monopolar electrodes, metal electrodes, wire electrodes, patch electrodes, cuff electrodes, clip electrodes, needle electrodes, or probe electrodes. 
     
     
         36 . The system of  claim 34 , further comprising a switch communicably coupled to the controller, wherein the switch includes one of a hand switch, a foot switch, a touch screen, a voice-activated switch, or a remote switch. 
     
     
         37 . The system of  claim 34 , wherein the stimulation energy is delivered by an energy form that includes at least one of mechanical, electrical, ultrasonic, photonic, or electromagnetic energy. 
     
     
         38 . A method for stimulating a respiratory muscle of a patient, comprising:
 a. positioning a stimulator adjacent a nerve or muscle capable of activating a respiratory muscle;   b. providing external respiratory support for at least 90% of a patient's breaths in a 24-hour period;   c. activating the stimulator to cause the respiratory muscle to contract;   d. varying at least one of a stimulation intensity or a stimulation rate; and   e. removing the external respiratory support from the patient.