Parasympathetic activation by vagus nerve stimulation

Abstract

The vagus nerve and branches of the vagus nerve are stimulated below the laryngeal nerve branch bifurcation in order to induce desired parasympathetic responses, such as decreased heart rate, without also triggering any adverse sympathetic responses. Stimulating surfaces of an open field bipolar electrode are positioned on or inserted through the pleural membrane overlying the vagus nerve at a location having substantially no cardiac sympathetic fibers adjacent to the vagus nerve. The open field bipolar electrodes can be securable-wire, needle, plate, or any other type of electrode suitable for being secured to the pleural membrane using one or more fastening mechanisms. Electrical stimuli are generated by a stimulator connected to the stimulating surfaces of the open field bipolar electrode by one or more leads.

1 . An apparatus comprising:
 a stimulator configured to generate one or more electric stimuli based at least in part on at least one stimulating parameter;   at least two leads, each of the at least two leads having a proximal end and a distal end, wherein the proximal end of each lead is electrically connected to the stimulator; and   at least one stimulating surface at the distal end of each of the at least two leads, wherein the at least one stimulating surface is configured to create an electrical field in response to receiving the one or more electric stimuli generated by the stimulator.   
     
     
         2 . The apparatus of  claim 1 , wherein the at least two leads and the at least one stimulating surface are provided as components of an open field bipolar electrode. 
     
     
         3 . The apparatus of  claim 2 , wherein the open field bipolar electrode comprises one of an epimysial electrode, a fascial electrode, a needle electrode, a wire electrode and a plate electrode. 
     
     
         4 . The apparatus of  claim 1 , wherein the at least two leads are configured to be secured to a pleural membrane of a subject using one or more of the following: sutures; surgical clips; surgical glue; barbs; coils; mesh; or corkscrew wire. 
     
     
         5 . The apparatus of  claim 4 , further comprising said one or more of the following: sutures; surgical clips; surgical glue; barbs; coils; mesh; or corkscrew wire. 
     
     
         6 . The apparatus of  claim 1 , wherein the at least one stimulating parameter comprises an electric pulse frequency selected from a range of 3 Hertz to 20 Hertz. 
     
     
         7 . The apparatus of  claim 1 , wherein the at least one stimulating parameter comprises an electric pulse duration selected from a range of 200 μs to 1000 μs. 
     
     
         8 . The apparatus of  claim 1 , wherein the at least one stimulating parameter comprises an electric current amperage selected from a range of 1 mA to 12 mA. 
     
     
         9 . The apparatus of  claim 1 , wherein the at least one stimulating parameter comprises a duty cycle having a 10 second ON period and a 5 second OFF period. 
     
     
         10 . The apparatus of  claim 1 , wherein the at least one stimulating parameter comprises a duty cycle comprising an ON period of up to 24 hours and an OFF period between 1 second to 2000 seconds. 
     
     
         11 . The apparatus of  claim 1 , wherein each stimulating surface of the at least one stimulating surface is between 0.5 mm to 5 mm in length and between 0.5 mm and 1.5 mm in width. 
     
     
         12 . The apparatus of  claim 1 , each stimulating surface of the at least one stimulating surface is between 0.5 mm to 5 mm in length and 0.5 mm to 5 mm in width. 
     
     
         13 . The apparatus of  claim 1 , wherein the at least two leads comprise a first lead and a second lead, wherein the at least one stimulating surface at the distal end of the first lead comprises a first stimulating surface, and wherein the at least one stimulating surface at the distal end of the second lead comprises a second stimulating surface that is positioned 1 mm to 5 mm away from the first stimulating surface. 
     
     
         14 . The apparatus of  claim 1 , wherein each of the at least two leads comprises a conducting wire that is at least partially surrounded by an insulating surface, and wherein each stimulating surface of the at least one stimulating surface at the distal end of each lead is formed at an exposed area where the conducting wire is not covered by the insulating surface. 
     
     
         15 . The apparatus of  claim 14 , wherein the conducting wire comprises platinum. 
     
     
         16 . The apparatus of  claim 1 , further comprising at least two insertion needles, wherein the distal end of each lead of the at least two leads is coupled to a respective insertion needle of the at least two insertion needles. 
     
     
         17 . The apparatus of  claim 1 , further comprising at least two caps, wherein each cap of the at least two caps is placed on the distal end of a respective lead of the at least two leads.