Motion-activated, closed-loop non-invasive vagus nerve stimulation for neurorehabilitation

Abstract

A system for neurorehabilitation is disclosed that includes a motion detector configured to generate a motion detection feedback signal, a transcutaneous auricular vagus nerve stimulation module, and a controller configured to receive the motion detection feedback signal and send a stimulation signal to the transcutaneous auricular vagus nerve stimulation module based on the motion detection feedback signal meeting a minimum threshold criteria. A method for neurorehabilitation is disclosed that includes the steps of detecting patient motor activity, determining if the detected patient motor activity meets a minimum threshold criteria, and stimulating a vagus nerve through transcutaneous auricular vagus nerve stimulation if the minimum threshold criteria is met.

What is claimed is: 
     
         1 . A system for neurorehabilitation comprising:
 a motion detector configured to generate a voluntary motion detection feedback signal;   a transcutaneous auricular vagus nerve stimulation module; and   a controller configured to receive the voluntary motion detection feedback signal and send a stimulation signal to the transcutaneous auricular vagus nerve stimulation module with a delay of 2 seconds or less based on the voluntary motion detection feedback signal meeting a minimum threshold criteria for contraction.   
     
     
         2 . The system of  claim 1 , wherein the transcutaneous auricular vagus nerve stimulation module comprises a surface electrode. 
     
     
         3 . The system of  claim 2 , wherein the stimulation signal comprises an electrical intensity greater than 0 mA and up to 10 mA, a frequency of greater than 0 Hz and up to 100 Hz, and a pulse width greater than Ops and up to 500 μs. 
     
     
         4 . The system of  claim 2 , wherein the stimulation signal comprises an electrical intensity greater than 0.5 mA and up to 5 mA, a frequency of greater than 10 Hz and up to and a pulse width greater than 100 μs and up to 250 μs. 
     
     
         5 . The system of  claim 1 , wherein the transcutaneous auricular vagus nerve stimulation module comprises a surface electrode configured to interface a head or neck area. 
     
     
         6 . The system of  claim 1 , wherein the transcutaneous auricular vagus nerve stimulation module is configured to stimulate an auricular branch of the vagus nerve. 
     
     
         7 . The system of  claim 1 , wherein the motion detector comprises one or more of an EMG electrode, an EEG electrode, a camera, a robotic apparatus, an exoskeleton apparatus and an accelerometer. 
     
     
         8 . The system of  claim 1 , wherein the motion detection feedback signal is based on a plurality of muscle activity feedback signals. 
     
     
         9 . The system of  claim 8 , wherein the muscle activity feedback signals are based on two or more muscles from the group consisting of flexor carpi radilalis, flexor capri ulnaris, biceps, triceps, anterior deltoid and middle deltoid. 
     
     
         10 . The system of  claim 8 , wherein the muscle activity signals are based on:
 at least a first signal from an upper limb indicative of movement from one or more of a trapezius, deltoid, biceps brachii, triceps, flexor/extensor carpi radialis, flexor/extensor digitorum, and flexor/extensor pollicis brevis; and   at least a second signal from a lower limb indicative of movement from one or more of a gluteus maximus, quadriceps femoris, anterior compartment of the leg, quadriceps femoris, foot inverters and evertors, biceps femoris, semitendinosus and semimembranosus.   
     
     
         11 . The system of  claim 1 , wherein the minimum threshold criteria comprises an EMG motor evoked potential of at least 50 uV. 
     
     
         12 . A method for neurorehabilitation comprising:
 detecting patient motor activity;   determining if the detected patient motor activity meets a minimum threshold criteria for contraction; and   stimulating a vagus nerve with a delay of 2 seconds or less through transcutaneous auricular vagus nerve stimulation if the minimum threshold criteria is met.   
     
     
         13 . The method of  claim 12 , wherein detecting patient motor activity comprises detecting muscle electrical activity. 
     
     
         14 . The method of  claim 12 , wherein detecting patient motor activity comprises detecting a plurality of muscle activity feedback signals. 
     
     
         15 . The method of  claim 12 , wherein detecting patient motor activity comprises patient imaging. 
     
     
         16 . The method of  claim 12 , wherein the plurality of muscle activity feedback signals are based on two or more muscles from the group consisting of flexor carpi radialis, flexor capri ulnaris, biceps, triceps, anterior deltoid and middle deltoid 
     
     
         17 . The method of  claim 12 , wherein the plurality of muscle activity feedback signals are based on:
 at least a first signal from an upper limb indicative of movement from one or more of a trapezius, deltoid, biceps brachii, triceps, flexor/extensor carpi radialis, flexor/extensor digitorum, and flexor/extensor pollicis brevis; and   at least a second signal from a lower limb indicative of movement from one or more of a gluteus maximus, quadriceps femoris, anterior compartment of the leg, quadriceps femoris, foot inverters and evertors, biceps femoris, semitendinosus and semimembranosus.   
     
     
         18 . The method of  claim 12 , wherein detecting patient motor activity comprises mechanical feedback from a robotic or exoskeleton apparatus. 
     
     
         19 . The method of  claim 12 , wherein stimulating a vagus nerve comprises stimulating an auricular branch of the vagus nerve. 
     
     
         20 . The method of  claim 12 , wherein the minimum threshold criteria comprises one or more of a minimum signal amplitude, a minimum signal frequency, a minimum signal duration, a comparison to a model signal, a comparison to a preset value, and a comparison to a previously measured signal. 
     
     
         21 . The method of  claim 12 , wherein the stimulation comprises an electrical intensity greater than 0 mA and up to 10 mA, a frequency of greater than 0 Hz and up to 100 Hz, and a pulse width greater than 0 μs and up to 500 μs. 
     
     
         22 . The system of  claim 12 , wherein the stimulation comprises an electrical intensity greater than 0.5 mA and up to 5 mA, a frequency of greater than 10 Hz and up to 25 Hz, and a pulse width greater than 100 μs and up to 250 μs. 
     
     
         23 . The method of  claim 12 , wherein the stimulation is delivered a head or neck area. 
     
     
         24 . The method of  claim 12 , wherein the minimum threshold criteria comprises an EMG motor evoked potential of at least 50 uV.