Implantable neurostimulators having reduced pocket stimulation

Abstract

Neurostimulators and methods of using neurostimulators are provided. The neurostimulator is implanted within a tissue pocket of a patient, and electrical energy is conveyed from the neurostimulator to stimulate a target tissue site remote from the tissue pocket. The neurostimulator has a case with which one or more electrodes are associated. The electrical energy is returned to the electrode(s) in a manner that prevents, or at least reduces, pocket stimulation that may otherwise occur due to the return of electrical energy to the case of the neurostimulator.

1 . (canceled) 
     
     
         2 . A method, comprising:
 delivering monopolar neurostimulation to targeted neural tissue using a neurostimulator that includes an electrically conductive outer case implanted within a tissue pocket and a lead extending away from the outer case toward the targeted neural tissue, the outer case being configured to provide a hermetically sealed compartment for internal electronics that are operably connected to the outer case and the lead to transmit electrical stimulation pulses through tissue between the lead and the outer case, wherein the monopolar neurostimulation includes a plurality of stimulation pulses having an amplitude and a pulse width;   detecting tissue pocket stimulation, wherein the tissue pocket stimulation occurs with high current density at the outer case which is attributable at least in part to geometry of the outer case;   responding to detection of tissue pocket stimulation including reducing the pulse width of stimulation pulses in response to the detection of tissue pocket stimulation and delivering the monopolar neurostimulation using the electrical pulses with the reduced pulse width.   
     
     
         3 . The method of  claim 2 , wherein the decreased pulse width is in the range of 10-100 μs. 
     
     
         4 . The method of  claim 3 , wherein the decreased pulse width equal to or less than 50 μs. 
     
     
         5 . The method of  claim 2 , further comprising responding to reducing the pulse width by automatically increasing the amplitude of the electrical pulses. 
     
     
         6 . The method of  claim 2 , wherein the outer case for the neurostimulator used to deliver the monopolar neurostimulation has an area equal to or less than 1000 mm2, thereby contributing to high current density. 
     
     
         7 . The method of  claim 2 , wherein the outer case for the neurostimulator used to deliver the monopolar neurostimulation has an area equal to or less than 200 mm2, thereby contributing to high current density. 
     
     
         8 . The method of  claim 2 , wherein the outer case for the neurostimulator used to deliver the monopolar neurostimulation has length less than 35 mm, thereby contributing to high current density. 
     
     
         9 . The method of  claim 2 , wherein the outer case for the neurostimulator used to deliver the monopolar neurostimulation has diameter less than 5 mm, thereby contributing to high current density. 
     
     
         10 . The method of  claim 2 , wherein delivering monopolar neurostimulation to targeted neural tissue includes delivering cathodic energy to the targeted neural tissue. 
     
     
         11 . The method of  claim 2 , wherein delivering monopolar neurostimulation to targeted neural tissue includes delivering cathodic energy to the targeted neural tissue. 
     
     
         12 . A method for operating a neurostimulator that includes an electrically conductive outer case implanted within a tissue pocket and a lead extending away from the outer case toward targeted neural tissue, the method comprising:
 delivering monopolar neurostimulation to the targeted neural tissue including transmitting electrical stimulation pulses have an amplitude and a pulse width through tissue between the lead and the outer case;   detecting tissue pocket stimulation, wherein the tissue pocket stimulation occurs with high current density at the outer case which is attributable at least in part to geometry of the outer case;   responding to detection of tissue pocket stimulation including reducing the pulse width of stimulation pulses in response to the detection of tissue pocket stimulation and delivering the monopolar neurostimulation using the electrical pulses with the reduced pulse width.   
     
     
         13 . The method of  claim 12 , wherein the decreased pulse width is in the range of 10-100 μs. 
     
     
         14 . The method of  claim 13 , wherein the decreased pulse width equal to or less than 50 μs. 
     
     
         15 . The method of  claim 12 , further comprising responding to reducing the pulse width by automatically increasing the amplitude of the electrical pulses. 
     
     
         16 . The method of  claim 12 , wherein the outer case for the neurostimulator used to deliver the monopolar neurostimulation has an area equal to or less than 1000 mm2, thereby contributing to high current density. 
     
     
         17 . A method for operating a neurostimulator that includes an electrically conductive outer case implanted within a tissue pocket and a lead extending away from the outer case toward targeted neural tissue, the method comprising:
 delivering monopolar neurostimulation to the targeted neural tissue including transmitting electrical stimulation pulses have an amplitude and a pulse width through tissue between the lead and the outer case, wherein the outer case has an area equal to or less than 200 mm2;   detecting tissue pocket stimulation, wherein the tissue pocket stimulation occurs with high current density at the outer case which is attributable at least in part to geometry of the outer case including the area of the outer case;   responding to detection of tissue pocket stimulation including reducing the pulse width of stimulation pulses to a pulse width within the range of 10-100 μs in response to the detection of tissue pocket stimulation and delivering the monopolar neurostimulation using the electrical pulses with the reduced pulse width.   
     
     
         18 . The method of  claim 17 , wherein the outer case for the neurostimulator used to deliver the monopolar neurostimulation has an area equal to or less than 200 mm2 and the decreased pulse width is equal to or less than 50 μs. 
     
     
         19 . The method of  claim 17 , further comprising responding to reducing the pulse width by automatically increasing the amplitude of the electrical pulses. 
     
     
         20 . The method of  claim 17 , wherein the geometry of the outer case for the neurostimulator includes a length less than 35 mm and a diameter less than 5 mm. 
     
     
         21 . The method of  claim 17 , wherein delivering monopolar neurostimulation to targeted neural tissue includes delivering cathodic energy to the targeted neural tissue, and wherein the tissue pocket includes larger nerves than nerves within the targeted neural tissue.