Method and system for modulating neural activity

Abstract

Methods and related systems for modulating neural activity by modulating neural activity in a nerve plexus of a subject are disclosed. Neural activity may be modulated by stimuli delivered via various types of stimulus sources. Neural modulation may be used, for example, to modulate an undesired sensation, such as pain. Delivery of stimuli for modulating neural activity may be controlled in part in based on an activity state of the subject.

What is claimed is: 
     
         1 .- 27 . (canceled) 
     
     
         28 . A neural modulation method, comprising:
 receiving an activity signal indicative of an activity state of a subject;   determining an activity state of the subject based on the activity signal;   delivering a nerve blocking stimulus to a nerve plexus of the subject responsive to the determined activity state of the subject, wherein the nerve blocking stimulus is adapted to modulate pain in the subject; and   determining that a desired pain modulation effect has been produced.   
     
     
         29 . The method of  claim 28 , including determining that the desired pain modulation effect has been produced by sensing a physiological parameter from the subject. 
     
     
         30 . The method of  claim 28 , including determining that the desired pain modulation effect has been produced by sensing a physical parameter from the subject. 
     
     
         31 . The method of  claim 28 , including determining that the desired pain modulation effect has been produced by obtaining qualitative or subjective reporting from the subject. 
     
     
         32 . The method of  claim 28 , wherein the activity signal includes a signal indicative of a physiological activity. 
     
     
         33 . The method of  claim 32 , wherein the physiological activity includes at least one of heart rate, respiration, brain activity, peripheral neural activity, muscle activity, or body temperature of the subject. 
     
     
         34 . The method of  claim 32 , wherein the activity signal includes an electroencephalographic signal, an electromyographic signal, an electrocardiographic signal, an electrocardiogram morphology, a heart rate, a blood pressure, a blood oxygenation, a respiration rate, a respiratory volume, a skin conductivity, a body temperature, a core temperature, a subcutaneous temperature, or a signal indicative of a chemical indicator. 
     
     
         35 . The method of  claim 28 , wherein the activity signal includes a signal indicative of a physical activity. 
     
     
         36 . The method of  claim 35 , wherein the physical activity includes posture, movement, motion, or acceleration of at least a portion of the body of the subject. 
     
     
         37 . The method of  claim 28 , wherein the nerve blocking stimulus includes a chemical blocking stimulus, an electrical blocking stimulus, a magnetic blocking stimulus, a thermal blocking stimulus, an acoustic blocking stimulus, an ultrasonic blocking stimulus, or an electromagnetic blocking stimulus. 
     
     
         38 . The method of  claim 28 , further comprising receiving a signal indicative of a sleep-related state of a subject. 
     
     
         39 . The method of  claim 38 , wherein the sleep-related state of a subject includes a rest state or a waking state. 
     
     
         40 . The method of  claim 28 , further comprising receiving a user input indicative of a user instruction to modify a definition of a first activity state or a second activity state. 
     
     
         41 . The method of  claim 40 , wherein the definition of the first activity state or the second activity state includes a threshold level. 
     
     
         42 . The method of  claim 28 , including delivering the nerve blocking stimulus to the nerve plexus of the subject responsive while the subject is in a first activity state, and discontinuing delivery of the nerve blocking stimulus when the subject is in a second activity state. 
     
     
         43 . The method of  claim 28 , further comprising modulating delivery of the nerve blocking stimulus responsive to determining that the desired pain modulation effect has been produced. 
     
     
         44 . The method of  claim 28 , wherein delivering the nerve blocking stimulus includes delivering energy to the nerve plexus in a targeted fashion with one or more energy source. 
     
     
         45 . The method of  claim 44 , wherein delivering the nerve blocking stimulus includes delivering energy to the nerve plexus in a targeted fashion with one or more energy source includes delivering the nerve blocking stimulus with one or more thermal energy source, one or more acoustic energy source, one or more electromagnetic energy source, one or more optical energy source, one or more electric field source, or one or more magnetic field source. 
     
     
         46 . The method of  claim 44 , wherein delivering the nerve blocking stimulus includes delivering energy to the nerve plexus in a targeted fashion with one or more energy source includes delivering the nerve blocking stimulus with two or more ultrasound transducers aimed and focused to produce interference of ultrasonic energy at an area of overlap. 
     
     
         47 . The method of  claim 44 , further comprising delivering a chemical blocking agent non-specifically relative to the nerve plexus. 
     
     
         48 . A neural modulation system, comprising:
 an activity signal input structure adapted to receive an activity signal indicative of an activity state of a subject;   a signal processing portion including circuitry for determining an activity state of the subject based on the activity signal;   circuitry for generating a stimulus control signal for controlling delivery of a nerve blocking stimulus to a nerve plexus of the subject responsive to the determined activity state of the subject, wherein the nerve blocking stimulus is adapted to modulate pain in the subject; and   circuitry for determining that a desired pain modulation effect has been produced.   
     
     
         49 . The neural modulation device of  claim 48 , further comprising one or more energy source configured to deliver energy to the nerve plexus in a targeted fashion to produce nerve blocking. 
     
     
         50 . The neural modulation device of  claim 49 , wherein the one or more energy source includes one or more thermal energy source, one or more acoustic energy source, one or more electromagnetic energy source, one or more optical energy source, one or more electric field source, or one or more magnetic field source. 
     
     
         51 . The neural modulation device of  claim 49 , wherein the one or more energy source includes two or more ultrasound transducers aimed and focused to produce interference of ultrasonic energy at an area of overlap. 
     
     
         52 . The neural modulation device of  claim 48 , wherein the circuitry for determining that a desired pain modulation effect has been produced is configured to determine that a desired pain modulation effect has been produced based on a physiological parameter sensed from the subject. 
     
     
         53 . The neural modulation device of  claim 48 , wherein the circuitry for determining that a desired pain modulation effect has been produced is configured to determine that a desired pain modulation effect has been produced based on a physical parameter sensed from the subject. 
     
     
         54 . The neural modulation device of  claim 48 , wherein the circuitry for determining that a desired pain modulation effect has been produced is configured to determine that a desired pain modulation effect has been produced based on a qualitative or subjective reporting received from the subject. 
     
     
         55 . The neural modulation device of  claim 48 , further comprising an activity sensor operatively connected to the activity signal input. 
     
     
         56 . The neural modulation device of  claim 48 , wherein the activity signal input is adapted to receive a signal indicative of at least one of a physiological activity or a physical activity. 
     
     
         57 . The neural modulation device of  claim 48 , further comprising a nerve blocking stimulus source.