Bipolar devices for modification of airways by transfer of energy

Abstract

This relates to a device for treating lung disease, and more particularly, relates to a device for exchanging energy with airway tissue such as that found in the airways of human lungs. The exchange of energy with this airway tissue in the airways reduces the ability of the airways to constrict and/or reduces the resistance within the airway to the flow of air through the airway.

1 - 78 . (canceled) 
   
   
       79 . An apparatus for delivering energy to airway tissue, comprising:
 a flexible elongated body having a proximal portion and a distal portion;   a radially expandable electrode array including a rounded tip and at least four elongated flexible electrodes projecting from the distal portion of the body and longitudinally relative to the body, wherein each electrode has a proximal end attached to the distal portion of the elongated body, a distal end attached to the rounded tip, and an active region between the proximal and distal ends;   a first electric cable configured to be attached to one pole of an RF energy source and a first plurality of the electrodes, and a second cable configured to be attached to an opposite pole of the RF energy source and a second plurality of the electrodes, wherein the first and second cables provide RF energy to the first and second plurality of electrodes in a bipolar manner; and   a deployment member extending along the elongated body and attached to the rounded tip, wherein proximal movement of the deployment member flexes the electrodes such that the active regions move away from a longitudinal axis of the elongated body to contact the airway.   
   
   
       80 . The apparatus of  claim 79  wherein the electrodes are equally spaced apart from each other. 
   
   
       81 . The apparatus of  claim 79  wherein the active regions are approximately 10 mm long. 
   
   
       82 . The apparatus of  claim 79  wherein opposing active regions of the electrodes are diametrically spaced apart from each other by a distance of 10-12 mm in a fully flexed expanded state. 
   
   
       83 . The apparatus of  claim 79 , further comprising a first thermocouple operatively coupled to one of the first plurality of electrodes and a second thermocouple operatively coupled to one of the second plurality of electrodes. 
   
   
       84 . The apparatus of  claim 79  wherein the electrodes are made from a flat wire positioned to flex so that the active regions move radially outward to a deployed configuration. 
   
   
       85 . The apparatus of  claim 79 , further comprising a power source that provides RF energy in bipolar fields within airway tissue such that the electrodes reach a temperature of 65° C. for an activation time of at least 3 seconds. 
   
   
       86 . The apparatus of  claim 79 , further comprising a power source that provides RF energy in bipolar fields within airway tissue such that the electrodes reach a temperature of 70° C. for an activation time of 2 seconds. 
   
   
       87 . The apparatus of  claim 79  wherein individual active regions form individual arches when moved radially outward. 
   
   
       88 . An apparatus for delivering energy to airway tissue, comprising:
 a flexible elongated body having a proximal portion and a distal portion;   a radially expandable electrode array including a rounded tip and at least four elongated flexible electrodes projecting longitudinally relative to the body, wherein each electrode has a proximal end attached to the distal portion of the elongated body, a distal end attached to the rounded tip, and an active region between the proximal and distal ends, and wherein the electrodes extend generally parallel to a longitudinal axis of the elongated body in a collapsed state and are configured to flex such that the active regions move radially outward relative to the longitudinal axis of the elongated body to contact the airway in an expanded state; and   a first electric cable configured to be attached to one pole of an RF energy source and a first plurality of the electrodes, and a second cable configured to be attached to an opposite pole of the RF energy source and a second plurality of the electrodes, wherein the first and second cables provide RF energy to the first and second plurality of electrodes in a bipolar manner such that airway smooth muscle tissue is debulked and the ability of the airway smooth muscle to contract is reduced.   
   
   
       89 . The apparatus of  claim 88  wherein the electrodes are equally spaced apart from each other. 
   
   
       90 . The apparatus of  claim 88  wherein the active regions are approximately 10 mm long. 
   
   
       91 . The apparatus of  claim 88  wherein opposing active regions of the electrodes are diametrically spaced apart from each other by a distance of 10-12 mm in a fully flexed expanded state. 
   
   
       92 . The apparatus of  claim 88 , further comprising a first thermocouple operatively coupled to one of the first plurality of electrodes and a second thermocouple operatively coupled to one of the second plurality of electrodes. 
   
   
       93 . The apparatus of  claim 88  wherein the electrodes are made from a flat wire positioned to flex so that the active regions move radially outward to a deployed configuration. 
   
   
       94 . The apparatus of  claim 88 , further comprising a power source that provides RF energy in bipolar fields within airway tissue such that the electrodes reach a temperature of 65° C. for an activation time of at least 3 seconds. 
   
   
       95 . The apparatus of  claim 88 , further comprising a power source that provides RF energy in bipolar fields within airway tissue such that the electrodes reach a temperature of 70° C. for an activation time of 2 seconds. 
   
   
       96 . The apparatus of  claim 88  wherein individual active regions form individual arches when moved radially outward. 
   
   
       97 . A method for treating asthma, comprising:
 inserting a radially expandable electrode array into an airway in a lung of a patient, the radially expandable electrode array including at least four elongated flexible electrodes projecting from the distal portion of the body and longitudinally relative to the body, wherein each electrode has a proximal end attached to the distal portion of the elongated body, a distal end attached to a tip, and an active region between the proximal and distal ends;   flexing the electrodes such that the active regions move radially outward relative to a longitudinal axis of the elongated body and contact a wall of the airway, wherein individual active regions extend longitudinally along the wall of the airway; and   delivering RF energy to the wall of the airway via the electrodes in a bipolar manner such that airway smooth muscle tissue is debulked and the ability of the airway smooth muscle to contract is reduced.   
   
   
       98 . The method of  claim 97  wherein delivering the RF energy comprises heating the electrodes to at least 65° C. for at least 3 seconds and then terminating the RF energy. 
   
   
       99 . The method of  claim 97  wherein delivering the RF energy comprises heating the electrodes to approximately 70° C. for approximately 2 seconds and then terminating the RF energy. 
   
   
       100 . The method of  claim 97  wherein flexing the electrodes comprises moving the tip proximally, and wherein the method further comprises releasing the tip after terminating the RF energy such that the electrodes exert a longitudinal force that drives the tip distally and moves the active regions radially inward relative to the longitudinal axis of the elongated body. 
   
   
       101 . The method of  claim 97  wherein:
 flexing the electrode comprises drawing a pull wire attached to the tip proximally such that the tip moves proximally;   delivering the RF energy comprises heating the electrodes to at least 65° C. for at least 3 seconds at a first treatment site in the airway and then terminating delivery of the RF energy;   releasing the pull wire after terminating delivery of the RF energy at the first treatment site, whereby the electrodes exert a longitudinal force that drives the tip distally and moves the active regions inward relative to the longitudinal axis of the elongated body;   moving the expandable electrode array proximally within the airway to a second treatment site;   pulling the pull wire proximally, which moves the tip proximally and causes the electrodes to flex such that the active regions move radially outward relative to the longitudinal axis of the elongated body and contact the wall of the airway at the second treatment site;   delivering the RF energy in a bipolar manner to the wall of the airway at the second treatment site such that the electrodes are heated to at least 65° C. for at least 3 seconds.