Method and apparatus for neural stimulation via the lymphatic system

Abstract

An implantable neural stimulation system includes an implantable medical device having a neural stimulation circuit and at least one implantable lead configured to allow one or more stimulation electrodes to be placed in one or more lymphatic vessels of a patient, such as the patient's thoracic duct and/or vessels branching from the thoracic duct. Neural stimulation pulses are delivered from the implantable medical device to one or more target regions adjacent to the thoracic duct or the vessels branching from the thoracic duct through the one or more stimulation electrodes.

1 . A system for delivering neural stimulation to a target region in a body having lymphatic vessels, the system comprising:
 a first electrode assembly including a first electrode base configured to be implanted into one of the lymphatic vessels and a first stimulation electrode on the first electrode base, the first electrode base configured to cause a portion of the one of the lymphatic vessels to substantially alter its natural path to contact the target region and maintain the contact between the portion of the one of the lymphatic vessels and the target region after an implantation of the first electrode assembly; and   an implantable medical device including a neural stimulation circuit adapted to deliver neural stimulation pulses through the first stimulation electrode.   
   
   
       2 . The system of  claim 1 , wherein the first electrode base comprises an elongate electrode base including one or more biases each configured to cause the portion of the one of the lymphatic vessels to substantially alter its natural path to contact the target region, the elongate electrode base having a stiffness allowing for maintaining the contact between the portion of the one of the lymphatic vessels and the target region after the implantation of the first electrode assembly. 
   
   
       3 . The system of  claim 1 , wherein the first electrode base comprises an expandable electrode base configured to cause the portion of the one of the lymphatic vessels to substantially alter its natural path to contact the target region, after being expanded. 
   
   
       4 . The system of  claim 3 , wherein the expandable electrode base comprises a stent, and the first electrode is incorporated into or integrated with the stent. 
   
   
       5 . The system of  claim 1 , further comprising a first implantable lead having a first distal end, a first proximal end configured to be connected to the implantable medical device, and a first elongate lead body between the first distal end and the first proximal end, and wherein the first electrode assembly is incorporated into the first implantable lead. 
   
   
       6 . The system of  claim 5 , wherein the first electrode assembly is incorporated into the first distal end. 
   
   
       7 . The system of  claim 5 , wherein the first electrode assembly is incorporated into the first elongate lead body. 
   
   
       8 . The system of  claim 5 , wherein the first electrode base further comprises a second stimulation electrode, and the neural stimulation circuit is adapted to deliver the neural stimulation pulses through the first stimulation electrode and the second stimulation electrode. 
   
   
       9 . The system of  claim 5 , further comprising a second stimulation electrode configured to be placed in a location external to the lymphatic vessels, and wherein the neural stimulation circuit is adapted to deliver the neural stimulation pulses through the first stimulation electrode and the second stimulation electrode. 
   
   
       10 . The system of  claim 9 , further comprising a second implantable lead configured to be subcutaneously implanted, the second implantable lead having a second distal end including the second stimulation electrode, a second proximal end configured to be connected to the implantable medical device, and a second elongate lead body between the distal end and the proximal end. 
   
   
       11 . The system of  claim 9 , wherein the second stimulation electrode is incorporated onto the implantable medical device. 
   
   
       12 . The system of  claim 5 , comprising a physiological sensor adapted to sense a physiological signal, and wherein the implantable medical device comprises:
 a sensing circuit, coupled to the physiological sensor, to process the physiological signal; and   an implant control circuit adapted to control the delivery of the neural stimulation pulses using the physiological signal.   
   
   
       13 . The system of  claim 12 , wherein the physiological sensor comprises an neural sensing electrode configured to sense a neural signal, the sensing circuit comprises a neural sensing circuit to process the neural signal, and the implant control circuit is adapted to control the delivery of the neural stimulation pulses using the processed neural signal. 
   
   
       14 . The system of  claim 13 , wherein the neural sensing electrode is the first stimulation electrode. 
   
   
       15 . The system of  claim 13 , wherein the implant control circuit comprises a closed-loop controller adapted to provide feedback control of the delivery of the neural stimulation pulses using the sensed neural signal as an input signal. 
   
   
       16 . The system of  claim 5 , wherein the implantable medical device comprises an implant control circuit adapted to control the delivery of the neural stimulation pulses using a plurality of stimulation parameters, the implant control circuit including:
 a parameter storage circuit to store values of the plurality of stimulation parameters; and   a parameter receiver to receive one or more programmed values of the plurality of stimulation parameters and to update the parameter storage circuit with the received one or more programmed values of the plurality of stimulation parameters.   
   
   
       17 . The system of  claim 16 , wherein the implantable medical device comprises an implant telemetry circuit to receive the one or more programmed values of the plurality of stimulation parameters. 
   
   
       18 . The system of  claim 17 , further comprising an external system communicatively coupled to the implantable medical device, the external system including:
 a user input device adapted to allow programming of the one or more programmed values of the parameters; and   an external telemetry circuit to transmit the one or more programmed values of the plurality of stimulation parameters to the implantable medical device.   
   
   
       19 . A method for delivering neural stimulation to a body having lymphatic vessels including a thoracic duct, the method comprising:
 delivering neural stimulation pulses from an implantable medical device to at least a first stimulation electrode placed in one of the lymphatic vessels.   
   
   
       20 . The method of  claim 19 , further comprising altering a natural path of the one of the lymphatic vessels to cause a portion of the one of the lymphatic vessels to contact a target region to which the neural stimulation are delivered using an electrode base configured to be implanted in the one of the lymphatic vessels, and wherein the first stimulation electrode is incorporated into or integrated with the electrode base. 
   
   
       21 . The method of  claim 19 , wherein delivering the neural stimulation pulses comprises delivering the neural stimulation pulses through a stimulation electrode placed in the thoracic duct. 
   
   
       22 . The method of  claim 19 , wherein delivering the neural stimulation pulses comprises delivering the neural stimulation pulses through a stimulation electrode placed in one of the vessels branching from the thoracic duct. 
   
   
       23 . The method of  claim 19 , wherein delivering the neural stimulation pulses comprises delivering the neural stimulation pulses through the first stimulation electrode and a second stimulation electrode placed in the one of the lymphatic vessels. 
   
   
       24 . The method of  claim 19 , wherein delivering the neural stimulation pulses comprises delivering the neural stimulation pulses through the first stimulation electrode and a second stimulation electrode placed in a location in the body external the lymphatic vessels. 
   
   
       25 . The method of  claim 19 , further comprising:
 sensing one or more physiological signals; and   controlling the delivery of the neural stimulation pulses using the one or more physiological signals.   
   
   
       26 . The method of  claim 25 , wherein sensing the one or more physiological signals comprises sensing a neural signal using the first stimulation electrode, and controlling the delivery of the neural stimulation pulses comprises controlling the delivery of the neural stimulation pulses using the neural signal. 
   
   
       27 . The method of  claim 19 , further comprising:
 controlling the delivery of the neural stimulation pulses using a plurality of stimulation parameters;   receiving one or more values of the plurality of stimulation parameters; and   storing the received one or more values of the plurality of the stimulation parameters.   
   
   
       28 . The method of  claim 27 , further comprising programming one or more values of the stimulation parameters according to a target to which the neural stimulation pulses are delivered, the target including one or more component of a nervous system. 
   
   
       29 . The method of  claim 28 , wherein delivering the neural stimulation pulses comprises delivering the neural stimulation pulses to a parasympathetic nerve. 
   
   
       30 . The method of  claim 29 , wherein delivering the neural stimulation pulses comprises delivering the neural stimulation pulses to a vagus nerve. 
   
   
       31 . The method of  claim 28 , wherein delivering the neural stimulation pulses comprises delivering the neural stimulation pulses to a sympathetic nerve. 
   
   
       32 . The method of  claim 28 , wherein delivering the neural stimulation pulses comprises delivering the neural stimulation pulses to a spinal cord. 
   
   
       33 . The method of  claim 28 , wherein delivering the neural stimulation pulses comprises delivering the neural stimulation pulses to baroreceptors.