Vagus nerve stimulation system

Abstract

A vagus nerve stimulation system for stimulating a vagus nerve in a biological subject, the system including a clip configured to be attached to a tragus of the subject, the clip including opposing arms configured so that a distal end of the arms are biased towards each other and electrodes positioned proximate a distal end of the arms on opposing faces so that the electrodes are urged into engagement with opposing faces of the tragus and a signal generator electrically connected to the electrodes, the signal generator being configured to generate at least one therapy signal that is applied to the vagus nerve within the tragus via the electrodes, to thereby modulate the vagus nerve.

The claims defining the invention are as follows: 
     
         1 ) A vagus nerve stimulation system for stimulating a vagus nerve in a biological subject, the system including:
 a) a clip configured to be attached to a tragus of the subject, the clip including:
 i) opposing arms configured so that a distal end of the arms are biased towards each other; and, 
 ii) electrodes positioned proximate a distal end of the arms on opposing faces so that the electrodes are urged into engagement with opposing faces of the tragus; and, 
   b) a signal generator electrically connected to the electrodes, the signal generator being configured to generate at least one therapy signal that is applied to the vagus nerve within the tragus via the electrodes, to thereby modulate the vagus nerve.   
     
     
         2 ) A nerve stimulation system according to  claim 1 , wherein the system includes a hook extending over and behind an ear of the subject to at least partially support the clip. 
     
     
         3 ) A nerve stimulation system according to  claim 2 , wherein the hook is configured to extend laterally from the clip so that the lead can loop over and behind an ear of the subject. 
     
     
         4 ) A nerve stimulation system according to any one of the  claims 1  to  3 , wherein the system includes a lead extending from the clip, the lead including connections configured to electrically connect the electrodes to the signal generator. 
     
     
         5 ) A nerve stimulation system according to  claim 4 , wherein the lead is configured to extend laterally from the clip so that the lead can loop over and behind an ear of the subject. 
     
     
         6 ) A nerve stimulation system according to  claim 4  or  claim 5 , wherein the lead is configured to extend from a distal end of one of the arms. 
     
     
         7 ) A nerve stimulation system according to any one of the  claims 4  to  6 , wherein the lead includes a sheath extending at least part way along a length of the lead and wherein the sheath defines a hook shaped to loop over and behind an ear of the subject. 
     
     
         8 ) A nerve stimulation system according to any one of the  claims 1  to  7 , wherein one of the arms is configured to be positioned within a concha of the user. 
     
     
         9 ) A nerve stimulation system according to any one of the  claims 1  to  8 , wherein the arms are pivotally connected about a mid-portion. 
     
     
         10 ) A nerve stimulation system according to any one of the  claims 1  to  9 , wherein a distal ends of the arms are biased together using a biasing mechanism. 
     
     
         11 ) A nerve stimulation system according to  claim 10 , wherein the biasing mechanism includes at least one of:
 a) a pivot;   b) a spring;   c) a rubber member;   d) a malleable member interconnecting the arms;   e) at least partially malleable arms;   f) an at least partially elastic member interconnecting the arms;   g) at least partially elastic arms; and,   h) magnets provided on the arms.   
     
     
         12 ) A nerve stimulation system according to any one of the  claims 1  to  11 , wherein a proximal outer face of the arms include a depression configured to allow a subject to engage the arms and bias the arms apart. 
     
     
         13 ) A nerve stimulation system according to any one of the  claims 1  to  12 , wherein the arms have at least one of:
 a) a length that is at least one of:
 i) greater than 15 mm; 
 ii) greater than 16 mm; 
 iii) greater than 17 mm; 
 iv) greater than 18 mm; 
 v) greater than 19 mm; 
 vi) greater than 20 mm; 
 vii) greater than 21 mm; 
 viii) less than 30 mm; 
 ix) less than 28 mm; 
 x) less than 27 mm; 
 xi) less than 26 mm; 
 xii) less than 25 mm; 
 xiii) less than 24 mm; 
 xiv) less than 23 mm; 
 xv) about 22 mm; and, 
 
 b) a width that is at least one of:
 i) greater than 5 mm; 
 ii) greater than 6 mm; 
 iii) greater than 7 mm; 
 iv) greater than 8 mm; 
 v) greater than 9 mm; 
 vi) greater than 10 mm; 
 vii) less than 16 mm; 
 viii) less than 15 mm; 
 ix) less than 14 mm; 
 x) less than 13 mm; 
 xi) less than 12 mm; 
 xii) about 11 mm. 
 
 
     
     
         14 ) A nerve stimulation system according to any one of the  claims 1  to  13 , wherein the electrodes are:
 a) substantially circular; 
 b) rounded rectangular; 
 c) rounded square; 
 d) at least partially dome shaped; 
 e) have a diameter of at least one of:
 i) greater than 4 mm; 
 ii) greater than 5 mm; 
 iii) greater than 6 mm; 
 iv) greater than 7 mm; 
 v) less than 12 mm; 
 vi) less than 11 mm; 
 vii) less than 10 mm; 
 viii) less than 9 mm; and, 
 ix) about 8 mm. 
 
 
     
     
         15 ) A nerve stimulation system according to any one of the  claims 1  to  14 , wherein a surface of the electrodes at least one of:
 a) is roughened; 
 b) includes grooves; 
 c) includes ridges; and, 
 d) is coated. 
 
     
     
         16 ) A nerve stimulation system according to any one of the  claims 1  to  15 , wherein a surface of the electrodes is coated with at least one of:
 a) an inert metal; and, 
 b) gold. 
 
     
     
         17 ) A nerve stimulation system according to any one of the  claims 1  to  16 , wherein therapy signals are signals having a frequency that is at least one of:
 a) less than 20 kHz; 
 b) less than 10 kHz; 
 c) less than 1 kHz; 
 d) less than 500 Hz; 
 e) less than 200 Hz; 
 f) less than 150 Hz; 
 g) less than 100 Hz; 
 h) less than 75 Hz; 
 i) greater than 1 Hz; 
 j) greater than 2 Hz; 
 k) greater than 5 Hz; 
 l) greater than 10 Hz; 
 m) greater than 20 Hz; 
 n) about 20 Hz; and, 
 o) about 50 Hz. 
 
     
     
         18 ) A nerve stimulation system according to any one of the  claims 1  to  17 , wherein therapy signals are signals having a pulse width of at least one of:
 a) less than 5,000 μs; 
 b) less than 2,500 μs; 
 c) less than 1,000 μs; 
 d) less than 500 μs; 
 e) less than 200 μs; 
 f) less than 100 μs; 
 g) less than 75 μs; 
 h) greater than 1 μs; 
 i) greater than 2 μs; 
 j) greater than 5 μs; 
 k) greater than 10 μs; 
 l) greater than 20 μs; and, 
 m) about 50 μs. 
 
     
     
         19 ) A nerve stimulation system according to any one of the  claims 1  to  18 , wherein the therapy signals are signals having a voltage that is at least one of:
 a) less than 50V; 
 b) less than 25V; 
 c) less than 10V; 
 d) less than 5V; 
 e) less than 2V; 
 f) less than 1V; 
 g) greater than 0.1V; 
 h) greater than 0.2V; 
 i) greater than 0.5V; and, 
 j) greater than 1V. 
 
     
     
         20 ) A nerve stimulation system according to any one of the  claims 1  to  19 , wherein the therapy signals are signals having a current that is at least one of:
 a) less than 50 mA; 
 b) greater than 0.1 mA; and, 
 c) between 0.1 mA and 36 mA. 
 
     
     
         21 ) A nerve stimulation system according to any one of the  claims 1  to  20 , wherein the therapy signals at least one of:
 a) are symmetrical; 
 b) are asymmetrical; 
 c) are monophasic; 
 d) are bi-phasic; 
 e) are tri-phasic; 
 f) are poly-phasic; and, 
 g) include multiple phases with at least one interspersed dwell. 
 
     
     
         22 ) A nerve stimulation system according to any one of the  claims 1  to  21 , wherein a respective therapy signal is applied to each of the electrodes. 
     
     
         23 ) A nerve stimulation system according to  claim 22 , wherein the respective therapy signals are at least one of:
 a) in phase; and,   b) out of phase.   
     
     
         24 ) A nerve stimulation system according to any of  claims 1  to  23 , wherein the lead includes at least one of:
 a) a respective conductor for each electrode; 
 b) at least one insulating layer; and, 
 c) a braided shield. 
 
     
     
         25 ) A nerve stimulation system according to any one of the  claims 1  to  24 , wherein the therapy signals are configured to at least one of:
 a) stimulate activity of the vagus nerve; and, 
 b) inhibit activity of the vagus nerve. 
 
     
     
         26 ) A nerve stimulation system according to any one of the  claims 1  to  25 , wherein the signal generator is mounted on the clip. 
     
     
         27 ) A nerve stimulation system according to any one of the  claims 1  to  26 , wherein the system includes a control system having a housing containing at least one of:
 a) the signal generator; 
 b) a power supply; and, 
 c) a controller. 
 
     
     
         28 ) A nerve stimulation system according to  claim 27 , wherein a lead extends from the clip to the housing. 
     
     
         29 ) A nerve stimulation system according to any of  claims 1  to  28 , wherein the system includes a controller configured to control the signal generator. 
     
     
         30 ) A nerve stimulation system according to  claim 29 , wherein the controller is configured to:
 a) determine therapy signal parameters; and,   b) control the signal generator in accordance with the therapy signal parameters.   
     
     
         31 ) A nerve stimulation system according to  claim 30 , wherein the controller is configured to determine the therapy signal parameters in accordance with at least one of:
 a) defined therapy signal parameters stored in a memory;   b) user input commands;   c) biofeedback;   d) neurofeedback;   e) signals from a sensor; and,   f) a selected therapy mode.   
     
     
         32 ) A nerve stimulation system according to any of  claims 29  to  31 , wherein the system includes a sensor configured to sense at least one subject parameter and wherein the controller is configured to:
 a) determine at least one subject parameter using signals from the sensor; and, 
 b) cause the signal generator to generate therapy signals in accordance with the at least one subject parameter. 
 
     
     
         33 ) A nerve stimulation system according to  claim 32 , wherein the sensor is at least one of:
 a) mounted on the clip proximate at least one electrode;   b) electrically coupled to at least one of the electrodes;   c) a wearable sensor;   d) provided on a wearable band; and,   e) provided on a wearable wrist band.   
     
     
         34 ) A nerve stimulation system according to  claim 32  or  claim 33 , wherein the sensor is at least one of:
 a) an inflammatory biomarker sensor; 
 b) a temperature sensor; 
 c) a blood oxygen sensor; 
 d) a pulse oximeter; 
 e) a heart rate sensor; and, 
 f) an impedance sensor. 
 
     
     
         35 ) A nerve stimulation system according to any of  claims 32  to  34 , wherein the at least one subject parameter includes at least one of:
 a) a presence, absence or concentration of an inflammatory biomarker; 
 b) a temperature; 
 c) a blood oxygen level; 
 d) a heart rate; 
 e) a heart rate variability; 
 f) an impedance; and, 
 g) a galvanic skin response. 
 
     
     
         36 ) A nerve stimulation system according to any of  claims 32  to  35 , wherein the controller is configured to:
 a) monitor a heart rate of the subject based on signals from the sensor; and, 
 b) cause the signal generator to generate the therapy signals at least partially in accordance with the feedback. 
 
     
     
         37 ) A nerve stimulation system according to any of  claims 32  to  36 , wherein the controller is configured to:
 a) cause the signal generator to generate progressively therapy signals having progressively changing parameters; 
 b) monitor a heart rate of the subject based on signals from the sensor whilst the therapy signals change; 
 c) detect changes in heart rate; 
 d) set a therapy signal parameter threshold based on a parameter of the therapy signal when changes in heart rate are detected; and, 
 e) cause the signal generator to generate therapy signals based on the therapy signal parameter threshold. 
 
     
     
         38 ) A nerve stimulation system according to  claim 37 , wherein the therapy signal parameter threshold is a therapy signal magnitude and is 50%-60% of the therapy signal magnitude being applied when the change in heart rate is detected. 
     
     
         39 ) A nerve stimulation system according to any of  claims 32  to  38 , wherein the controller is configured to:
 a) cause the signal generator to generate the therapy signals; 
 b) monitor changes in a heart rate of the subject based on signals from the sensor, in response to the applied therapy signals; and, 
 c) at least one of:
 i) cause the signal generator to generate therapy signals based on monitored changes in heart rate; and, 
 ii) analyse monitored changes in heart rate to determine a heart variability in response to the applied therapy signals. 
 
 
     
     
         40 ) A nerve stimulation system according to  claim 39 , wherein the controller is configured to use the heart rate variability to generate an inflammatory indicator indicative of a presence, absence or degree of inflammatory markers within the subject. 
     
     
         41 ) A nerve stimulation system according to  claim 40 , wherein the inflammatory indicator is inversely proportional to the heart rate variability. 
     
     
         42 ) A nerve stimulation system according to any of  claims 39  to  41 , wherein the controller is configured to use the heart rate variability to generate a predictive indicator indicative of a responsiveness to the therapy signals. 
     
     
         43 ) A nerve stimulation system according to  claim 42 , wherein the predictive indicator is indicative of a responsiveness to atrial fibrillation therapy. 
     
     
         44 ) A nerve stimulation system according to any of  claims 29  to  43 , wherein the controller is configured to:
 a) determine feedback using user input commands; and, 
 b) cause the signal generator to generate the therapy signals in accordance with the feedback. 
 
     
     
         45 ) A nerve stimulation system according to any of  claims 29  to  44 , wherein the controller is configured to:
 a) cause the signal generator to generate therapy signals having progressively changing parameters; and, 
 b) selecting one or more therapy signal parameters in response to user input commands. 
 
     
     
         46 ) A nerve stimulation system according to any of  claims 29  to  45 , wherein the parameters include at least one of:
 a) a therapy signal pulse width; 
 b) a therapy signal magnitude; and, 
 c) a therapy signal frequency; and, 
 d) a therapy signal waveform shape. 
 
     
     
         47 ) A nerve stimulation system according to  claim 46 , wherein the controller is configured to progressively increase the therapy signal in steps of at least one of:
 a) 0.1 mA;   b) 0.2 mA;   c) 0.5 mA;   d) 0.8 mA;   e) 1 mA;   f) 1.5 mA; and,   g) 2 mA.   
     
     
         48 ) A nerve stimulation system according to any of  claims 29  to  47 , wherein the controller is configured to:
 a) determine selection of a therapy mode in accordance with user input commands; and, 
 b) control the signal generator in accordance with the selected mode. 
 
     
     
         49 ) A nerve stimulation system according to  claim 48 , wherein the system includes a number of therapy modes stored in a store, each therapy mode defining a sequence of therapy signals and wherein the controller is configured to cause the signal generator to generate the sequence of therapy signals. 
     
     
         50 ) A nerve stimulation system according to any of  claims 29  to  49 , wherein in a research mode the controller is configured to at least one of:
 a) select a therapy signal magnitude in response to user input commands and progressively decrease the therapy signal magnitude to zero; and, 
 b) . 
 c) deliver non-electrical stimulus. 
 
     
     
         51 ) A nerve stimulation system according to any of  claims 29  to  50 , wherein the controller includes at least one of:
 a) at least one processing device; 
 b) a software application executed by a client device; and, 
 c) an external controller wirelessly connected to at least one of:
 i) the signal generator; and, 
 ii) at least one sensor. 
 
 
     
     
         52 ) A nerve stimulation system according to any of  claims 29  to  51 , wherein the system includes a stimulator configured to apply stimulus to the subject. 
     
     
         53 ) A nerve stimulation system according to  claim 51 , wherein the stimulator includes at least one of:
 a) an audio stimulator;   b) a vibratory stimulator;   c) an optical stimulator; and,   d) a thermal stimulator.   
     
     
         54 ) A nerve stimulation system according to  claim 51  or  claim 52 , wherein the stimulator is incorporated into the clip. 
     
     
         55 ) A nerve stimulation system according to any of  claims 51  to  54 , wherein the stimulator is controlled by a controller to cause stimulus to be applied in conjunction with the therapy signals. 
     
     
         56 ) A nerve stimulation system according to any of  claims 1  to  55 , wherein the nerve stimulation system is configured to treat at least one of:
 a) depression; 
 b) mental health disorders; 
 c) autonomic nervous system dysfunction; 
 d) stress; 
 e) heart failure; 
 f) traumatic brain injury; 
 g) disorders of consciousness; 
 h) inflammatory disorders; 
 i) autoimmune disorders; 
 j) cognitive dysfunction; 
 k) infections; 
 l) symptoms of infections; 
 m) respiratory dysfunction; 
 n) post viral syndrome; 
 o) fatigue; 
 p) post traumatic stress disorder; 
 q) cancer; 
 r) fibromyalgia; 
 s) postural orthostatic tachycardia syndrome; 
 t) myocardial infarction; and, 
 u) atrial fibrillation. 
 
     
     
         57 ) A nerve stimulation system according to any of  claims 1  to  56 , wherein the nerve stimulation system is configured to enhance at least one of:
 a) physical performance; and, 
 b) cognitive function. 
 
     
     
         58 ) A vagus nerve stimulation method for stimulating a vagus nerve in a biological subject, the method including:
 a) attaching a clip to a tragus of the subject, the clip including:
 i) opposing arms configured so that a distal end of the arms are biased towards each other; and, 
 ii) electrodes positioned proximate a distal end of the arms on opposing faces so that the electrodes are urged into engagement with opposing faces of the tragus; and, 
   b) using a signal generator electrically connected to the electrodes to generate at least one therapy signal that is applied to the vagus nerve within the tragus via the electrodes to thereby modulate the vagus nerve.   
     
     
         59 ) A system for treating at least one of depression and atrial fibrillation, the apparatus including:
 a) a clip configured to be attached to a tragus of the subject, the clip including:
 i) opposing arms configured so that a distal end of the arms are biased towards each other; and, 
 ii) electrodes positioned proximate a distal end of the arms on opposing faces so that the electrodes are urged into engagement with opposing faces of the tragus; and, 
   b) a signal generator electrically connected to the electrodes, the signal generator being configured to generate at least one therapy signal that is applied to the vagus nerve within the tragus via the electrodes to thereby modulate the vagus nerve.   
     
     
         60 ) A method for treating at least one of depression and atrial fibrillation, the method including:
 a) attaching a clip to a tragus of the subject, the clip including:
 i) opposing arms configured so that a distal end of the arms are biased towards each other; and, 
 ii) electrodes positioned proximate a distal end of the arms on opposing faces so that the electrodes are urged into engagement with opposing faces of the tragus; and, 
   b) using a signal generator electrically connected to the electrodes to generate at least one therapy signal that is applied to the vagus nerve within the tragus via the electrodes to thereby modulate the vagus nerve.   
     
     
         61 ) A vagus nerve stimulation system for stimulating a vagus nerve in a biological subject, the system including:
 a) a securing member configured to be attached to a tragus of the subject so that the electrodes are urged into engagement with opposing faces of the tragus; and,   b) a signal generator electrically connected to the electrodes, the signal generator being configured to generate at least one therapy signal that is applied to the vagus nerve within the tragus via the electrodes, to thereby modulate the vagus nerve.   
     
     
         62 ) A vagus nerve stimulation method for stimulating a vagus nerve in a biological subject, the method including:
 a) attaching a securing member to a tragus of the subject so that electrodes are urged into engagement with opposing faces of the tragus; and,   b) using a signal generator electrically connected to the electrodes to generate at least one therapy signal that is applied to the vagus nerve within the tragus via the electrodes to thereby modulate the vagus nerve.