Electrode structures and methods for their use in cardiovascular reflex control

Abstract

Devices, systems and methods are described by which the blood pressure, nervous system activity, and neurohormonal activity may be selectively and controllably reduced by activating baroreceptors. A baroreceptor activation device is positioned near a baroreceptor, preferably a baroreceptor located in the carotid sinus. A control system may be used to modulate the baroreceptor activation device. The control system may utilize an algorithm defining a stimulus regimen which promotes long term efficacy and reduces power requirements/consumption. The baroreceptor activation device may utilize electrodes to activate the baroreceptors. The electrodes may be adapted for connection to the carotid arteries at or near the carotid sinus, and may be designed to minimize extraneous tissue stimulation.

1 . An extravascular baroreceptor activation device comprising: 
 a multi-channel electrode assembly having a flexible base adapted to be placed extravascularly around a vessel within a patient;    a plurality of selectively activateable electrodes coupled to the electrode assembly; and    a connection cable adapted to couple the device to a control system for controlling the device, wherein the electrodes are electrically coupled to the connection cable.    
   
   
       2 . The device of  claim 1 , wherein the electrodes are stretchable.  
   
   
       3 . The device of  claim 1 , wherein the flexible base is comprised of a material selected from the group consisting of: silicone, polyurethane, and latex.  
   
   
       4 . The device of  claim 1 , wherein one or more electrodes are adapted to sense a physiologic parameter.  
   
   
       5 . The device of  claim 1 , wherein at least one of the plurality of electrodes is configured as an anode-cathode pair including a ring generally surrounding a pad ring, the anode-cathode pair being electrically coupled to the connection cable.  
   
   
       6 . The device of  claim 1 , further comprising a control chip operably coupled between the connection cable and the electrodes, the control chip adapted to receive and decode a coded control signal, and further adapted to selectively activate or deactivate one or more electrodes in response to the decoded signal.  
   
   
       7 . The device of  claim 6 , wherein the control chip is operably coupled to a feedback sensor.  
   
   
       8 . The device of  claim 1 , wherein the electrodes are at least partially encapsulated in the flexible base.  
   
   
       9 . A method of maintaining efficacy of a baroreflex therapy, comprising: 
 providing a baroreceptor activation device including:    a multi-channel electrode assembly having a flexible base adapted to be placed extravascularly around a vessel within a patient;    at least four selectively activateable electrodes coupled to the electrode assembly; and    a connection cable adapted to couple the device to a control system for controlling the device, wherein the electrodes are electrically coupled to the connection cable;    selectively activating two or more electrodes with the control system to induce a baroreceptor signal in a patient and provide a baroreflex therapy;    altering the activating two or more electrodes to activate a different two or more electrodes to maintain the effectiveness of the therapy.    
   
   
       10 . The method of  claim 9 , wherein the baroreceptor activation device further includes a controller operably coupled between the connection cable and the electrodes, the controller adapted to receive and decode a coded control signal, and further adapted to selectively activate or deactivate one or more electrodes in response to the decoded signal.  
   
   
       11 . The method of  claim 10 , wherein the controller is operably coupled to a feedback sensor.  
   
   
       12 . The method of  claim 11 , wherein the baroreflex therapy is modified based on data provided by the feedback sensor.  
   
   
       13 . The method of  claim 9 , wherein one or more electrodes are adapted to sense a physiologic parameter.  
   
   
       14 . A method of mapping a baroreceptor-containing location, the method comprising: 
 providing a baroreceptor activation device including:    a multi-channel electrode assembly having a flexible base adapted to be placed extravascularly around a vessel within a patient;    at least four selectively activateable electrodes coupled to the electrode assembly; and    a connection cable adapted to couple the device to a control system for controlling the device, wherein the electrodes are electrically coupled to the connection cable;    selectively activating a first set of electrodes and measuring a parameter indicative of baroreceptor activation in response to activating the first set of electrodes;    selectively activating additional sets of electrodes, and measuring a parameter indicative of baroreceptor activation in response to activating the additional sets of electrodes; and    determining a set of electrodes which maximize the baroreceptor response for use in a baroreflex therapy.    
   
   
       15 . The method of  claim 14 , wherein one or more of the electrodes are adapted to sense a physiologic parameter.  
   
   
       16 . The method of  claim 14 , wherein the baroreceptor activation device further includes a controller operably coupled between the connection cable and the electrodes, the controller adapted to receive and decode a coded control signal, and further adapted to selectively activate or deactivate one or more electrodes in response to the decoded signal.  
   
   
       17 . The method of  claim 16 , wherein the controller is operably coupled to a feedback sensor.  
   
   
       18 . The method of  claim 17 , wherein the baroreflex therapy is modified based on data provided by the feedback sensor.  
   
   
       19 . A baroreflex activation device comprising: 
 an electrode assembly having a base adapted to be placed extravascularly generally around a vessel within a patient;    more than four electrodes coupled to the electrode assembly, each electrode being individually selectively activable; and    a connection cable adapted to couple the device to a control system that controls the baroreflex activation device, the connection cable including more than four conductors, each conductor electrically coupled to one of the electrodes.    
   
   
       20 . A baroreflex activation device comprising: 
 an electrode assembly including:    a base adapted to be placed extravascularly generally around a vessel within a patient; and    more than two channels defined in the base, each channel having a plurality of selectively activable electrodes positioned relative to that channel; and    a connection cable adapted to couple the device to a control system that controls the baroreflex activation device.    
   
   
       21 . The device of  claim 20 , further comprising a controller operably coupled between the connection cable and the more than two channels, the controller adapted to receive and decode a coded control signal, and further adapted to selectively activate or deactivate one or more channels in response to the decoded signal.  
   
   
       22 . The device of  claim 20 , wherein each channel contains at least four electrodes.  
   
   
       23 . The device of  claim 22 , wherein each electrode comprises an anode cathode pair having one ring electrode surrounding a point electrode.