Patent Publication Number: US-2022226654-A1

Title: Auricular nerve field stimulation device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This is a divisional application of U.S. patent application Ser. No. 17/040,766, filed Sep. 23, 2020, which is a U.S. national stage entry of PCT Application No. PCT/US2019/029172, filed Apr. 25, 2019, which claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 62/662,995, filed Apr. 26, 2018, the disclosures of which are incorporated herein by reference in their entireties. 
    
    
     FIELD OF THE DISCLOSURE 
     This disclosure relates generally to electrical stimulation devices, and more specifically to auricular stimulation devices for stimulating auricular nerve fields. 
     BACKGROUND 
     Percutaneous electrical stimulation devices are known and used to provide therapy to humans and animals. As one example of such devices, conventional electrical acupuncture devices are used to percutaneously supply electrical stimulation to acupuncture points including those in the region of the ear. 
     Located within the ear are cranial nerves V, VII, IX, X which anastomose (connect) directly into the brain and branches of the greater and lesser occipital nerves anastomosing directly into the cervical spine. There are distinct areas of the auricle on both the dorsal and ventral aspect which carry a predominance/concentration of the cranial nerves, peripheral nerves, arterial branches, and neurovascular bundles. In this regard, other known electrical stimulation devices are used to percutaneously supply electrical stimulation to such auricular peripheral nerve fields for various purposes including pain management. 
     Non-percutaneous electrical stimulation devices are also known and used to provide therapy to humans and animals. One example of such a non-percutaneous device is a conventional transcutaneous electrical nerve stimulation (TENS) device which typically uses two or more non-percutaneous electrodes spaced apart along an area or region of the skin of a human or animal to provide low-voltage current to the surface of the skin for the purpose of pain management. One particular class of TENS devices includes so-called interferential therapy (IFT) or interferential current (IFC) devices which typically use four or more non-percutaneous electrodes spaced apart along an area or region of the skin. The operation of conventional IFT devices differ from conventional TENS in that voltages with differing frequencies are applied across diagonally-spaced pairs of the electrodes to create lower frequency “interference” currents in a region of the anatomy located between the four spaced-apart electrodes. 
     SUMMARY 
     The present disclosure may comprise one or more of the features recited in the attached claims, and/or one or more of the following features and combinations thereof. In one aspect, a non-percutaneous trans-auricular nerve field stimulation device may comprise a first plurality of spaced-apart electrically conductive electrodes each arranged to non-percutaneously contact a ventral aspect of an auricle of a human ear, a second plurality of spaced-apart electrically conductive electrodes each arranged to non-percutaneously contact a dorsal aspect of the auricle, and electrical circuitry coupled to the first and second plurality of electrodes and configured to selectively apply electrical stimulation signals to at least one of the first plurality of electrodes and the second plurality of electrodes to cause a first set of trans-auricular currents to flow through the auricle between the first plurality of electrodes and respective ones of the second plurality of electrodes paired therewith according to a first pairing, and to cause a second set of trans-auricular currents to flow through the auricle between the first plurality of electrodes and respective ones of the second plurality of electrodes paired therewith according to a second pairing different from the first pairing, the first and second sets of trans-auricular currents to stimulate at least one auricular nerve field within the auricle. 
     In another aspect, a non-percutaneous trans-auricular nerve field stimulation device may comprise a first electrically conductive electrode arranged to non-percutaneously contact a first portion of a ventral aspect of an auricle of a human ear, a second electrically conductive electrode arranged to non-percutaneously contact a first portion of a dorsal aspect of the auricle opposite the first portion of the ventral aspect, a third electrically conductive electrode arranged to non-percutaneously contact a second portion of the ventral aspect of auricle spaced apart from the first portion of the ventral aspect, a fourth electrically conductive electrode arranged to non-percutaneously contact a second portion of the dorsal aspect of the auricle opposite the second portion of the ventral aspect, and electrical circuitry coupled to the first, second third and fourth electrodes, the electrical circuitry configured to (i) selectively apply a first electrical stimulation signal to at least one of the first and second electrodes to cause a first trans-auricular current to flow therebetween and transversely through the auricle in a direction parallel to a transverse plane of the auricle, (ii) selectively apply a second electrical stimulation signal to at least one of the third and fourth electrodes to cause a second trans-auricular current to flow therebetween and transversely through the auricle in the direction parallel to the transverse plane of the auricle, (iii) selectively apply a third electrical stimulation signal to at least one of the second and third electrodes to cause a third trans-auricular current to flow therebetween and diagonally through the auricle, and (iv) selectively apply a fourth electrical stimulation signal to at least one of the first and fourth electrode to cause a fourth trans-auricular current to flow therebetween and diagonally through the auricle. 
     In a further aspect, a non-percutaneous trans-auricular nerve field stimulation device may comprise a first electrically conductive electrode arranged to non-percutaneously contact a ventral aspect of an auricle of a human ear, a second electrically conductive electrode arranged to non-percutaneously contact a dorsal aspect of the auricle opposite the first electrically conductive electrode, a third electrically conductive electrode arranged to non-percutaneously contact the ventral aspect of auricle spaced apart from the first electrically conductive electrode, a fourth electrically conductive electrode arranged to non-percutaneously contact the dorsal aspect of the auricle opposite the third electrically conductive electrode, and electrical circuitry coupled to the first, second third and fourth electrodes, the electrical circuitry configured to (i) selectively apply a first electrical stimulation signal of a first frequency to at least one of the first and fourth electrode to cause a first trans-auricular current to flow therebetween and diagonally through the auricle, and (ii) selectively apply a second electrical stimulation signal of a second frequency, different than the first frequency, to at least one of the second and third electrodes to cause a second trans-auricular current to flow therebetween and diagonally through the auricle, wherein the first and second trans-auricular currents define an interferential current within the auricle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       This disclosure is illustrated by way of example and not by way of limitation in the accompanying Figures. Where considered appropriate, reference labels have been repeated among the Figures to indicate corresponding or analogous elements. 
         FIG. 1  is a side elevational view of an embodiment of a non-percutaneous trans-auricular nerve field stimulation device. 
         FIG. 2  is a cross-sectional view of the device of  FIG. 1  as viewed along section lines  2 - 2 . 
         FIG. 3  is a side-elevational view of the device of  FIGS. 1 and 2  mounted to ventral and dorsal aspects of an auricle of a human ear. 
         FIG. 4  is a cross-sectional view of the device illustrated in  FIG. 3  as viewed along section lines  4 - 4 . 
         FIG. 5  is a table illustrating the possible combinations of trans-auricular current flow between the four electrodes of the device illustrated in  FIGS. 1-4  using a single voltage gating circuit or multiple voltage gating circuits with common ground references. 
         FIG. 6  is another table illustrating some of the possible combinations of trans-auricular current flow between the four electrodes of the device illustrated in  FIGS. 1-4  using two voltage gating circuits with decoupled ground references. 
         FIG. 7  is a side elevational view of another embodiment of a non-percutaneous trans-auricular nerve field stimulation device. 
         FIG. 8  is a simplified diagram illustrating one example trans-auricular current flow between the six electrodes of the device illustrated in  FIG. 7  using voltage gating circuits with common ground references. 
         FIG. 9A  is a side elevational view of an embodiment of a hybrid electrode assembly having a non-percutaneous electrode surrounding a percutaneously insertable needle electrode. 
         FIG. 9B  is a perspective view of the hybrid electrode assembly of  FIG. 9A . 
         FIG. 10  is a plan view of a human ear demonstrating an example placement of multiple ones of the hybrid electrode assemblies of  FIGS. 9A and 9B . 
         FIG. 11  is a cross-sectional view of the placed hybrid electrode assemblies illustrated in  FIG. 10  as viewed along section lines  11 - 11 . 
         FIG. 12  is a cross-sectional view similar to  FIG. 11  illustrating an alternate wire connection scheme to the hybrid electrode assemblies of  FIG. 11 . 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWING 
     While the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawing and will herein be described in detail. It should be understood, however, that there is no intent to limit the concepts of the present disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives consistent with the present disclosure and the appended claims. 
     References in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases may or may not necessarily refer to the same embodiment. Further, when a particular feature, structure or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure or characteristic in connection with other embodiments whether or not explicitly described. Further still, it is contemplated that any single feature, structure or characteristic disclosed herein may be combined with any one or more other disclosed feature, structure or characteristic, whether or not explicitly described, and that no limitations on the types and/or number of such combinations should therefore be inferred. 
     The present disclosure is directed to a device and method using at least two non-percutaneous electrodes mounted in contact with the skin of the dorsal aspect of a human or animal auricle and at least two non-percutaneous electrodes mounted in contact with the skin of the ventral aspect of the same auricle. Electrical stimulation signals are selectively applied to the electrodes to direct current flow in multiple directions through the auricle to effectuate trans-auricular, multi-directional peripheral nerve field stimulation within the auricle. 
     Definitions 
     For purposes of this disclosure, the following terms are defined. Like terms recited in the appended claims are to be interpreted consistently with the following terms: 
     Auricle—the visible portion of a human or animal hear residing outside of the human or animal head. 
     Dorsal aspect—rear surface of the auricle. 
     Ventral aspect—front surface of the auricle. 
     Coronal plane of the auricle—a plane dividing the auricle into the dorsal and ventral aspects. 
     Transverse plane of the auricle—a plane passing through the dorsal and ventral aspects of auricle, perpendicular to the coronal plane of the auricle, and dividing the auricle into top and bottom portions. 
     Trans-auricular—transversely through the auricle from the dorsal aspect to the ventral aspect and/or vice versa. 
     Trans-auricular current—current passing transversely through the auricle from the dorsal aspect to the ventral aspect and/or vice versa. 
     Non-percutaneous(ly) contact or contacting—physically contacting but not penetrating, piercing or otherwise breaking the skin. 
     Percutaneous insertion—penetrating or piercing the skin. 
     Interferential current—as between four electrodes placed on the auricle with two spaced apart along the ventral aspect and the remaining two spaced apart along the dorsal aspect, and with a current having a first frequency established diagonally through the auricle between one ventral electrode and a spaced apart one of the dorsal electrodes and another current having a second frequency established diagonally through the auricle between the other ventral electrode and the spaced apart other dorsal electrode, an interferential current in a space within the auricle intersected by the two currents has a frequency equal to the difference between the first and second frequencies. 
     First Embodiment 
     Referring to  FIGS. 1-4 , an embodiment is shown of a non-percutaneous trans-auricular nerve field stimulation device  10 . The device  10  includes multiple non-percutaneous electrodes, e.g., A, B, C and D in the embodiment illustrated in  FIGS. 1-4 , and electrical circuitry, e.g., circuitry  14  illustrated in  FIGS. 1 and 3 , for generating electrical stimulation signals and supplying the generated electrical stimulation signals to the electrodes. The electrodes are non-percutaneous in that they are configured to be positioned in contact the surface of the skin but not to pierce, penetrate or otherwise break through the surface of the skin, and electrical circuitry for generating and applying electrical stimulation signals to the electrodes. The electrodes are also electrically conductive and serve to deliver the electrical stimulation signals to the tissues within the auricle via contact with the skin surfaces of the ventral and dorsal aspects of the auricle as will be described in greater detail below. In one example embodiment, the electrodes are provided in the form of a low-resistance, high electrical conductivity, high-density silicone connecters such as those commercially available from Fujipoly America Corp. of Carteret, N.J. under the trade name ZEBRA® Elastomeric Electronic Connectors. In alternate embodiments, one or more of the electrodes may be provided in the form of rigid, semi-rigid or flexible electrodes made from or including one or more electrically conductive materials, examples of which include, but are not limited to, copper, aluminum, gold, silver, platinum, palladium, beryllium, nickel, tungsten, titanium, stainless steel, or the like. In some embodiments, the material(s) used to form the electrodes may be restricted, for example, to omit or minimize common allergy-causing materials such as nickel. In some embodiments, low-resistance contact between one or more of the electrodes A, B, C, D and the skin of the auricle  30  may be enhanced by providing conventional electrically conductive gel or other electrically conductive substance on the skin of the auricle  30  and/or on the surface(s) of one or more of the electrodes A, B, C, D prior to making contact between the electrodes and the auricle  30 . 
     In some embodiments, the electrodes, e.g., A, B, C and D depicted in  FIGS. 1-4 , and the electrical circuitry, e.g.,  14  depicted in  FIGS. 1 and 3 , are mounted to or otherwise carried by a flexible (or semi-flexible) carrier  12  configured to be operatively attached to an auricle of a human or animal. In the illustrated embodiment, the flexible carrier  12  is specifically shaped for operative attachment to an auricle  30  of a human, although it will be understood that alternative shapes for attachment to human ears and/or other shapes specific to one or more animal ears are intended to fall within the scope of this disclosure. In the embodiment illustrated in  FIGS. 1 and 3 , the flexible carrier  12  illustratively includes an elongated main body portion  12 A which is sized and configured to extend longitudinally along at least a portion of a helix  34  of an auricle  30  of a human ear  32  and to wrap transversely at least partially about that portion of the helix  34  as illustrated most clearly in  FIG. 3 . 
     An upper wing member  12 B is defined at an upper or top end of the elongated main body  12 A and a lower wing member  12 C is defined at a lower end of body  12 A. The upper wing member  12 B is sized to extend over at least a first portion of the ventral aspect  36  of the auricle  30  and to extend over at least a first portion of the dorsal aspect  38 . In this regard, the upper wing member  12 B includes a first wing  12 B 1  which extends transversely away from the corresponding upper end of the main body  12 A in one direction, e.g., a forward direction, and a second wing  12 B 2  extending transversely away from the corresponding upper end of the main body  12 A in an opposite direction, e.g., a rearward direction. The first wing  12 B 1  is configured to extend over and attach to the first portion of the ventral aspect  36 , and the second wing  12 B 2  is configured to extend over and attach to the first portion of the dorsal aspect  38 , with the upper wing member  12 B wrapped around the helix  34  and attached to the helix  34  between the first and second wings  12 B 1 ,  12 B 2  as illustrated in  FIG. 3 . 
     One of the electrodes A is illustratively mounted to the first wing  12 B 1  and another of the electrodes B is mounted to the second wing  12 B 2 . At least a portion of the electrode A is exposed at the bottom surface of the first wing  12 B 1 , as illustrated by example in  FIG. 2 , such that the electrode A contacts, and remains in contact with, the skin of the first portion of the ventral aspect  36  of the auricle  30  when the upper wing  12 B is attached to the first portion of the ventral aspect  36  of the auricle  30 . Likewise, at least a portion of the electrode B is exposed at the bottom surface of the second wing  12 B 2  such that the electrode B contacts, and remains in contact with, the skin of the first portion of the dorsal aspect  38  of the auricle  30  when the upper wing  12 B is attached to the first portion of the dorsal aspect  38  of the auricle  30 . It is to be understood that the first portion of the ventral aspect  36  to which the electrode A makes contact may be or include any portion of the ventral aspect  36  including, but not limited to, the scapha, the antihelical fold, the antihelix, the upper crus of the antihelix, the lower crus of the antihelix, the triangular fossa, the concha, the crux of the helix and the concha and the concha cava, as these anatomical terms are generally understood. The first portion of the dorsal aspect  38  to which the electrode B makes contact may be or include any portion of the dorsal aspect  38  that is generally opposite (transversely) the portion of the ventral aspect  36  to which the electrode A is disposed in contact. 
     A lower wing member  12 C is defined at a lower or bottom end of the elongated main body  12 A opposite the upper or top end of the main body  12 A. The lower wing member  12 C is sized to extend over at least a second portion of the ventral aspect  36  of the auricle  30  and to extend over at least a second portion of the dorsal aspect  38 . In this regard, the lower wing member  12 C includes a first wing  12 C 1  which extends transversely away from the corresponding lower end of the main body  12 A in the same direction as that of the first wing  12 B 1  of the upper wing member  12 B, and a second wing  12 C 2  extending transversely away from the corresponding lower end of the main body  12 A in an opposite direction, i.e., in the same direction as that of the second wing  12 B 2  of the upper wing member  12 B. 
     The first wing  12 B 1  is configured to extend over and attach to the first portion of the ventral aspect  36 , and the second wing  12 B 2  is configured to extend over and attach to the first portion of the dorsal aspect  38 , with the upper wing member  12 B wrapped around the helix  34  and attached to the helix  34  between the first and second wings  1261 ,  12 B 2  as illustrated in  FIG. 3 . The electrode C is illustratively mounted to the first wing  12 C 1  and the electrode D is mounted to the second wing  12 C 2 . At least a portion of the electrode C is exposed at the bottom surface of the first wing  12 C 1  such that the electrode C contacts, and remains in contact with, the skin of the second portion of the ventral aspect  36  of the auricle  30  when the lower wing  12 C is attached to the second portion of the ventral aspect  36  of the auricle  30 . Likewise, at least a portion of the electrode D is exposed at the bottom surface of the second wing  12 C 2  such that the electrode D contacts, and remains in contact with, the skin of the second portion of the dorsal aspect  38  of the auricle  30  when the lower wing  12 C is attached to the second portion of the dorsal aspect  38  of the auricle  30 . The second portion of the ventral aspect  36  to which the electrode C makes contact may be or include any portion of the ventral aspect  36  below that to which the electrode A makes contact. Depending upon the area of the ventral aspect  36  to which the electrode A makes contact, which may illustratively vary from application to application, may be or include any suitable remaining portion of the ventral aspect  36  including, but not limited to, the scapha, the antihelical fold, the antihelix, the upper crus of the antihelix, the lower crus of the antihelix, the triangular fossa, the concha, the crux of the helix, the concha and the concha cava. The second portion of the dorsal aspect  38  to which the electrode D makes contact may be or include any portion of the dorsal aspect  38  that is generally opposite (transversely) the portion of the ventral aspect  36  to which the electrode D is disposed in contact. 
     The carrier  12  further includes an electrical circuit mounting portion  12 E to which electrical circuitry  14  is mounted, as will be described in detail below, and a circuit extension member  12 D between the main body  12 A and the electrical circuit mounting portion  12 E. Illustratively, the circuit extension member  12 D extends rearwardly from a portion the main body  12 A between the upper and lower wing members  12 B,  12 C, e.g., in the same directions as the wings  12 B 2  and  12 C 2 , and the electrical circuit mounting portion  12 E is thus likewise rearward relative to the main body  12 A. In alternate embodiments, the electrical circuit mounting portion  12 E may extend from other portions of the main body  12 A. In any case, a number, M, of electrical conductors extend along the various portions of the carrier  12  to electrically connect each of the electrodes A, B, C and D to the electrical circuitry  14 . M may be any positive integer. In some embodiments, one or more, or all, of the electrical conductors are embedded within the carrier  12 , and in other embodiments one or more, or all, of the electrical conductors are attached to the top or bottom surface of the carrier  12 . 
     As illustrated by example in  FIG. 2 , an adhesive layer  20  may cover all or one or more portions of the bottom surface of the carrier  12  for the purpose of attaching, e.g., affixing, the carrier  12  to the auricle  30  as illustrated in  FIG. 3  and described above. In some such embodiments, a removable layer  22 , such as paper or other such layer, may cover the adhesive layer  20  to protect the adhesive layer  20  prior to application. The removable layer  22 , in embodiments which include it, is to be removed prior to attachment of the carrier  12  to the auricle  30  as illustrated in  FIG. 3 . It will be appreciated that the adhesive layer  20  illustrated in  FIG. 2  represents only one example structure and technique for attaching the flexible carrier  12  to the auricle  30 , and that this disclosure contemplates alternatively or additionally using one or more other conventional structures and techniques for attaching, affixing, mounting or otherwise securing the flexible carrier  12  to the auricle  30 . In one example embodiment, the carrier  12  is provided in the form of a woven fabric material, although this disclosure contemplates alternate embodiments in which the carrier  12  may be or include, but should not be limited to, a non-woven fabric, one or more other woven or non-woven textiles, latex or one or more suitable plastic materials such as polyvinylchloride (PVC), polyethylene, and/or polyurethane. 
     Referring now specifically to  FIG. 1 , the electrical circuitry  14  mounted to or otherwise carried by the electrical circuit mounting portion  12 E of the carrier  12  illustratively includes signal generation circuitry  15  and at least one power source  16  electrically connected to the signal generation circuitry  14  via at least one corresponding electrical conductor  17 . In some embodiments, the electrical circuitry  14  further illustratively includes a number, N, of voltage adjustment switches  18   1 - 18   N , electrically connected to the signal generation circuitry  14  via a corresponding number, N, of electrical conductors  19   1 - 19   N , where N may be any positive integer. The signal generation circuitry  15  is configured and operable, as will be described in greater detail below, to selectively apply electrical stimulation signals to one or more of the electrodes A, B, C, D to cause one or more trans-auricular currents to flow through the tissue of the auricle  30  between one or more of the electrodes A, B in contact with the ventral aspect  36  and one or more of the electrodes C, D in contact with the dorsal aspect  38  so as to stimulate one or more auricular nerve fields within the auricle  30 . 
     As further illustrated in  FIG. 1 , an embodiment of the signal generation circuitry  14  illustratively includes at least one control circuit  40  electrically coupled to the at least one power source  16  and to any number, N, conventional gating circuits  46   1 - 46   N , wherein N may be any positive integer as described above. In one embodiment, the at least one control circuit  40  is illustratively provided in the form of at least one conventional processor or controller  42  communicatively coupled to a conventional memory  44 , wherein the memory  44  has instructions, i.e., one or more programs, stored therein which, when executed by the processor or controller  42 , cause the processor or controller  42  to generate electrical stimulation control signals which are provided to the one or more gating circuits  46   1 - 46   N . The one or more gating circuits  46   1 - 46   N  is/are, in turn, responsive to the electrical stimulation control signals produced by the processor or controller  42  to produce the electrical stimulation signals to be applied to one or more of the electrodes A, B, C, D using electrical power produced by the at least one power source  16 . In alternate embodiments, the at least one control circuit  40  may be provided in other forms such as one or a combination of analog and/or digital hardware circuits. 
     The one or more gating circuits  46   1 - 46   N  are illustratively controlled by the at least one control circuit  40  to selectively apply voltages to one or more of the electrodes A, B, C, D as will be described in greater detail below. In some embodiments, the at least one control circuit  40  may include the one or more gating circuits  46   1 - 46   N . In some embodiments, one or more voltage adjustment switches  18   1 - 18   N , e.g., one for each gating circuit, is/are provided to allow adjustment of the maximum and/or minimum voltage(s) produced by the gating circuits. Illustratively, such gating circuit(s), in embodiments which include it/them, may be provided in the form of conventional pressure sensitive voltage adjustment switches, although other conventional voltage adjustment switches or actuators may alternatively be used. In any case, one or more of the voltage adjustment switches  18   1 - 18   N  may be configured and/or modified in one embodiment so as to be adjusted only during manufacturing and/or subsequent testing, and in other embodiments one or more of the voltage adjustment switches  18   1 - 18   N  may be configured and/or modified so as to be adjustable by the user and/or person(s) assisting the user. 
     In the embodiment illustrated in  FIG. 1 , a single power source  16  is shown mounted to or otherwise carried by the carrier  12 . In one embodiment, the power source  16  is a DC power source, e.g., illustratively provided in the form of a conventional battery. In other embodiments, the power source  16  may be or include one or more other conventional AC and/or DC voltage and/or current sources or storage devices. In some embodiments, two or more power sources  16  of any type may be included. In embodiments which include only a single power source  16  as shown, the single power source  16  supplies electrical power to all electrical power consuming circuits including the one or more gating circuits  18   1 - 18   N . In some embodiments which include two or more such gating circuits, the signal generation circuitry  14  may be configured such that all such gating circuits illustratively share a common electrical power reference potential, e.g., ground reference. In other embodiments which include two or more gating circuits, the signal generation circuitry  14  may be configured such that the electrical power references of at least two of the gating circuits are decoupled from one another. In any case, the circuit components of the signal generation circuitry  15  is/are illustratively operable, e.g., programmed, electrically interconnected and/or otherwise configured, to control one or more attributes of one or more of the electrical stimulation signals provided to one or more of the electrodes A, B, C, D. Examples of such attributes may be or include, but should not be limited to, switching frequency, duty cycle, signal duration, pause time between signal applications, maximum and/or minimum voltage level, maximum and/or minimum current level, polarity of voltage applied across two or more of the electrodes, signal sequence application duration and overall therapy duration in which at least one electrical stimulation signal is produced. 
     Referring now to  FIG. 4 , a cross-sectional diagram is shown as viewed along section lines  4 - 4  of  FIG. 3 . As illustrated in  FIG. 4 , the carrier  12  is attached to the auricle  30 , e.g., via an adhesive layer  20 , such that the electrodes A and C are in contact with the skin surface of the ventral aspect  36  of the auricle  30  and are spaced apart from one another along the ventral aspect  36 , and such that the electrodes B and D are similarly in contact with the skin surface of the dorsal aspect  38  of the auricle  30  and are spaced apart from one another along the dorsal aspect  38 . The electrode B is illustratively aligned with the electrode A and the electrode D is illustratively aligned with the electrode C. The illustrated arrangement is preferred but not strictly required as, in practice, the electrodes A, B and or the electrodes C, D may be somewhat offset relative to one another. In either case, the electrodes A, B, C, D are arranged to be responsive to electrical stimulation signals supplied thereto to cause trans-auricular current to flow through the auricle  30 , in either direction, between electrodes A and B, between electrodes C and D, between electrodes A and D and between electrodes B and C. As will be described in greater detail below, the electrical stimulation signals may be controlled to cause only one such trans-auricular current to flow through the auricle  30  at any one time, to cause any combination of such trans-auricular currents to simultaneously flow through the auricle  30  and/or to cause a sequence of any such trans-auricular current(s) to flow through the auricle  30  over time and/or a sequence of times. 
     Referring now to  FIG. 5 , a table  50  is shown of all possible voltage polarity combinations that could be applied to the electrodes A, B, C, D using at least one DC voltage source  16 . As there are four such electrodes A, B, C, D, there are 2 4 =16 possible combinations. Indeed, in embodiments which include K electrodes, where K is any positive, and typically even, integer, the total number of possible voltage polarity combinations that could be applied to such electrodes is 2K. The arrow-tipped lines represent the directions of current flow through the auricle  30  in response to the applied voltages. It is evident from these depictions that the voltages applied to the electrodes A, B, C, D are applied simultaneously, and are physically applied either by a single gating circuit  46  or by multiple gating circuits sharing a common electrical power source reference. Only polarity combinations 1 and 16 fail to produce current flow, and the remaining combinations result in current flow through the auricle  30  in a direction parallel to the transverse plane of the auricle  30 , e.g., the two through-currents depicted in polarity combination 7, current flow through the auricle  30  diagonally between electrodes A, D and/or B, C, e.g., the two diagonal currents depicted in polarity combination 6, and/or current flow along the skin, and at least partially into the auricle tissue, of the ventral aspect  36  and/or the dorsal aspect  38 , e.g., the current flowing between electrodes A and C along the skin surface of the ventral aspect  36  and the current flowing between electrodes D and B along the skin surface of the dorsal aspect  38 , as depicted in polarity combination 7. 
     As described above, it is also possible to decouple the power source references of two or more gating circuits which apply electrical stimulation pulses to the electrodes A, B, C, D. Such an arrangement effectively modifies the current flow possibilities depicted in  FIG. 5  by directing current flow only between specifically paired ones of the electrodes A, B, C, D. Referring to  FIG. 6 , for example, a table  60  is shown depicting four possible trans-auricular current flow scenarios using two reference (ground) decoupled gating circuits VG 1  and VG 2 . In gating combination 1, a positive voltage is applied by VG 1  between electrodes A and B, and a separate (i.e., decoupled) positive voltage is simultaneously applied by VG 2  between electrodes C and D. The result is the simultaneous flow of a first trans-auricular current through the auricle  30  from electrode A toward electrode B, and a second trans-auricular current through the auricle  30  from electrode C toward electrode D. Both such currents flow in a direction that is parallel to the physiological transverse plane of the auricle  30 . In gating combination 2, the polarities of the VG 1  and VG 2  are reversed, resulting in the flow of the same first and second trans-auricular currents but in the opposite direction as those depicted in gating combination 1. 
     In gating combination 3, a positive voltage is applied by VG 1  between electrodes A and D, and a separate (i.e., decoupled) positive voltage is simultaneously applied by VG 2  between electrodes C and B. The result is the simultaneous flow of a third trans-auricular current through the auricle  30  from electrode A toward electrode D, and a fourth trans-auricular current through the auricle  30  from electrode C toward electrode B. The third trans-auricular current flows through the auricle  30  in a downward diagonal direction between electrodes A and D and the fourth trans-auricular current flows through the auricle  30  in a downward diagonal direction between the electrodes C and B. In gating combination 4, the polarities of the VG 1  and VG 2  are reversed, resulting in the flow of the same third and fourth trans-auricular currents but each in opposite directions as those depicted in gating combination 3. 
     As is evident from  FIGS. 5 and 6 , various trans-auricular current flows can be established by controllably and selectively pairing the electrodes A and C contacting the ventral aspect  36  of the auricle  30  with different ones of the electrodes B and D contacting the dorsal aspect  38 , and then further controlling the polarities of the applied voltages to control trans-auricular current flow direction. Using the gating combinations illustrated in  FIG. 6  as one example, VG 1  and VG 2  are set in gating combinations 1 and 2 to a first pairing in which electrode A is paired with electrode B and in which electrode C is paired with electrode D. In gating combinations 3 and 4, VG 1  and VG 2  are set to a second pairing in which electrode A is paired with electrode D and in which electrode B is paired with electrode C. Electrical stimulation signals generated by the electrical circuitry  14  are then applied to the different pairings, e.g., one pairing after the other to cause a first set of trans-auricular currents to flow through auricle  30 , e.g., using gating combinations 1 and/or 2, and to then cause a second set of trans-auricular currents to flow through the auricle  30 , e.g., using gating combinations 3 and/or 4. Such applications of the electrical generation signals can be applied sequentially, i.e., such that one set of trans-auricular current flows but not the other and then vice versa, or simultaneously using gating circuits that share a common reference potential, e.g., ground reference, as illustrated in  FIG. 5 , or using gating circuits having decoupled references, e.g., ground references, as illustrated in  FIG. 6 . 
     It should be apparent from the foregoing description that the electrical circuit  14  may be programmed or otherwise configured to selectively apply electrical stimulation signals, e.g., in the form of voltage or voltage differentials, to various combinations of the electrodes A, B, C, D, simultaneously and/or sequentially and with any desired signal attributes as described above, for the purpose of causing corresponding trans-auricular currents to flow through the auricle  30  to provide therapy by stimulating at least one auricular nerve field within the auricle  30 . One example sequence of such electrical stimulation signals for providing auricular nerve field stimulation is the following, although those skilled in the art will recognize that this sequence represents only one of many different possible therapy approaches that may be implemented using the device  10 . It will be understood that all such different therapy approaches implementable using the device  10  are intended to fall within the scope of this disclosure. In any case, the following example sequence will assume the use of two ground reference-decoupled gating circuits controllable to selectively apply voltages and voltage differentials to the electrodes A, B, C, D as illustrated in  FIG. 6 . 
     Example Therapy Sequence 
     The following pattern of items 1-16 is illustratively repeated sequentially for P time units with a rest or pause time between each repeated pattern (in which no electrical stimulation signals are applied) of Q time units. The total therapy time is R time units. 
     1. Apply S volts according to combination 1 at T hertz for U time units. 
     2. Rest or pause V time units. 
     3. Apply S volts according to combination 2 at T hertz for U time units. 
     4. Rest or pause V time units. 
     5. Apply S volts according to combination 1 at W hertz for U time units. 
     6. Rest or pause V time units. 
     7 Apply S volts according to combination 2 at W hertz for U time units. 
     8. Rest or pause V time units. 
     9. Apply S volts according to combination 3 at T hertz for U time units. 
     10. Rest or pause V time units. 
     11. Apply S volts according to combination 4 at T hertz for U time units. 
     12. Rest or pause V time units. 
     13. Apply S volts according to combination 3 at W hertz for U time units. 
     14. Rest or pause V time units. 
     15. Apply S volts according to combination 4 at W hertz for U time units. 
     16. Rest or pause V time units. 
     Example values of variables P-W are the following, although it will be understood that in other implementations one or more of P-W may take on different values: 
     P=15 minutes. 
     Q=1 minute. 
     R=72 hours. 
     S=4.2 volts. 
     T=1 Hz. 
     U=1 millisecond. 
     V=2000 milliseconds. 
     W=10 Hz. 
     It will be further understood that in some embodiments one or more of the items 1-16 may be omitted and/or executed at a different point in the pattern, such that the sequential pattern may include any combination of any of items 1-16 executed in any order. In some alternate embodiments, the voltage applied between electrodes A and D in any or all of steps 9, 11, 13 and 15 may have a different frequency than the voltage applied between electrodes B and C so as to establish an interferential current in a space within the auricle  30  intersected by the two currents flowing between the pairs A, D and B, C of the four electrodes A, B, C and D. 
     Second Embodiment 
     The first embodiment of the non-percutaneous trans-auricular nerve field stimulation device  10  is illustrated in  FIGS. 1-6  and described above as including four electrodes A, B, C, D with two electrodes in spaced-apart contact with the ventral aspect  36  of the auricle  30  and with the remaining two electrodes in spaced-apart contact with the dorsal aspect  38 . It will be understood, however, that no limit on the total number of electrodes and/or electrode pairs is intended or should be inferred. In this regard, a second embodiment of a non-percutaneous trans-auricular nerve field stimulation device  100  is illustrated in  FIGS. 7 and 8  which includes a total of 6 electrodes A-F with three of the electrodes A, E and C in spaced-apart contact with the ventral aspect  36  of the auricle  30  and with the remaining three electrodes B, F and D in spaced-apart contact with the dorsal aspect  38 . The carrier  120 , like the carrier  12  illustrated in  FIGS. 1-3 , includes a main body  120 A, an upper wing member  120 B defining first and second wings  120 B 1  and  120 B 2  to which the electrodes A and B are respectively mounted, a lower wing member  120 C defining first and second wings  120 C 1  and  120 C 2  to which the electrodes C and D are respectively mounted, an electrical circuit mounting portion  120 F to which the electrical circuitry  14  is mounted and a circuit extension member  120 E between the main body  120 A and the electrical circuit mounting portion  120 F. Unlike the carrier  12  illustrated in  FIGS. 1-3 , the carrier  120  further includes a middle wing  120 D extending transversely away from the main body between, and in the same direction as, the wings  120 B 1  and  120 B 2 . The electrode E is mounted to the middle wing  120 D and the electrode F is mounted to the circuit extension member  120 F. In the illustrated embodiment, the electrodes A, E and C are respectively aligned with one another transversely about an imaginary longitudinal line bisecting the main body  120 A, although it will be understood that such alignment is not strictly required as other possible locations of the electrodes relative to the carrier  120  are contemplated. 
     With the illustrated electrode arrangement, a total of 2 6 =64 possible combinations of current flow combinations can be realized via selective application of voltage potentials to and between various ones of the electrodes A-F, and in this regard one example combination is illustrated in  FIG. 8 . As with the device  10  illustrated in  FIGS. 1-6 , the electrical circuitry  14  may include one or more gating circuits. If multiple gating circuits are included, two or more such gating circuits may share a common reference potential, e.g., ground reference, and/or two or more gating circuits may have decoupled references, e.g., decoupled ground references. 
     Third Embodiment 
     The first and second embodiments of the auricular nerve field stimulation device  10  and  100  illustrated in  FIGS. 1-6 and 7-8  respectively include four or more non-percutaneous electrodes spaced apart from one another in trans-auricular pairs as described above. A third embodiment replaces at least one of the multiple non-percutaneous, trans-auricular electrode pairs with hybrid, trans-auricular electrode pairs each having at least one non-percutaneously contacting electrode and at least one needle electrode for percutaneous insertion into the auricle  30  of the ear  32 . An embodiment of such a hybrid electrode is illustrated in  FIGS. 9A and 9B  in the form of a hybrid electrode assembly  200 . 
     Referring to  FIGS. 9A and 9B , the hybrid electrode assembly  200  includes an electrically non-conductive (i.e., electrically insulating) housing  202  in the form of a generally circular disk having a generally planar surface  214 A upon which an electrically conductive ring  204  is formed or attached in a conventional manner, and into which an insulated electrical conductor  206  extends into electrical contact, i.e., attachment, with the ring  204 . In the illustrated embodiment, the ring  204  circumscribes the housing  202 , although in alternate embodiments the ring  204  may be segmented into two or more pieces each electrically connected to the conductor  206 . An outer periphery of the ring  204  is illustratively adjacent to an outer periphery of the circular housing  202 , although in alternate embodiments the outer periphery of the ring  204  may be inboard of the outer periphery of the housing  202  such that at least a portion of the surface  214 A of the housing  202  extends beyond the outer periphery of the ring  204 . In one example implementation, which should not be considered to be limiting in any way, the circular housing  202  has a height or thickness of about 2 millimeters (mm) and a diameter of about 3 mm, although in alternate implementations the height or thickness may be more or less than 2 mm and/or the diameter may be more or less than 3 mm. Moreover, it will be understood that the circular disk configuration of the housing  202  illustrated in  FIGS. 9A and 9B  is provided only by way of illustration, and that in alternate embodiments the housing  202  may have other shapes or configurations. 
     A needle housing  208 , also illustratively in the form of a generally circular disk, is coupled to a surface  214 B of the housing  202  opposite the surface  214 A. In one embodiment, the needle housing  208  is separate from the housing  202  and is attached or affixed thereto in a conventional manner, although alternate embodiments are contemplated in which the needle housing  208  is integral with the housing  202  such that the housings  202  and  208  are of unitary construction. In any case, an insulated electrical conductor  212  extends into the needle housing  208  and is electrical connected to an electrically conductive needle or needle electrode  210  carried by the needle housing  208 . The needle or needle electrode  210  extends from the needle housing  208  and centrally through the housing  202  such that a portion of the needle  210  extends outwardly away from the surface  214 A of the housing  202 . As best shown in  FIG. 9B , an inner periphery of the electrically conductive ring  204  surrounds the needle electrode  210  with the needle electrode  210  spaced apart from the ring  204  by a ring-shaped portion  216  of the surface  214 A of the housing  202 . The electrically conductive needle electrode  210  is thus electrically isolated from the electrically conductive ring  204  by the housings  202  and  218 , and the electrical conductors  206 ,  212  are independent from one another with each attached to a respective one of the ring  204  and the needle electrode  210 . In the illustrated embodiment, the hybrid electrode assembly  202  carries a single needle electrode  210 , although in alternate embodiments the needle electrode  210  may be augmented with one or more additional needle electrodes each electrically connected to the electrical conductor  212 . 
     In some embodiments, at least one trans-auricular pair of non-percutaneous electrodes illustrated in  FIGS. 1-8  may be replaced by a pair of the hybrid electrode assemblies  200  likewise placed in a trans-auricular relationship relative to one another with the needle electrodes  210  thereof percutaneously inserted into the auricle  30  and advanced therein until the electrically conductive rings  204  thereof non-percutaneously contact the skin about the respective needle electrodes  210 . In some such embodiments, all of the trans-auricular pairs of non-percutaneous electrodes illustrated in  FIGS. 1-8  may be replaced by corresponding pairs of the hybrid electrode assemblies  200 . In other embodiments, the hybrid electrode assemblies  200  may be placed, in trans-auricular pairs, at locations or positions along the auricle  30  different from that illustrated in  FIG. 3 , as can the non-percutaneous electrodes illustrated in  FIGS. 1-8 . 
     Referring to  FIGS. 10 and 11 , for example, an implementation of an alternate auricular nerve field stimulation device  10 ′ is shown in which the electrodes are provided in the form of two trans-auricular pairs  200 A,  200 B and  200 C,  200 D of the hybrid electrode assemblies  200 . The hybrid electrode assembly  200 A may illustratively be placed on the ventral aspect  36  of the auricle  30  generally above the antihelix  33  and in the triangular fossa  35 , and the hybrid electrode assembly  200 B may be placed on the dorsal aspect  38  across from the hybrid electrode assembly  200 A such that the electrode assemblies  200 A,  200 B form a trans-auricular pair of electrodes. The hybrid electrode assembly  200 C may, in the illustrated embodiment, be placed on the ventral aspect  36  of the ear lobe  37 , and the hybrid electrode assembly  200 D may be placed on the dorsal aspect  38  of the ear lobe  37  across from the hybrid electrode assembly  200 C such that the electrode assemblies  200 C,  200 D form another trans-auricular pair of electrodes. It will be understood that in other implementations either or both trans-auricular pairs of the electrode assemblies  200 A- 200 D may be placed at other locations along the auricle, and/or that the device  10 ′ may include two or more additional trans-auricular pairs of hybrid electrode assemblies  200  and/or non-percutaneous electrodes placed at any location(s) along the auricle  30 . 
     In any case, the hybrid electrode assemblies  200  may, in some embodiments, be carried by, i.e., be operatively coupled to, the flexible carrier  12  illustrated in  FIGS. 1-4 and 7 , although in other embodiments the hybrid electrode assemblies may each be individually coupled to the auricle  30 . In the latter case, each of the housings  202  may illustratively be fitted with an individual, adhesive-backed, flexible carrier as described above. Alternatively, a suitable adhesive or other attachment medium may be applied to the region  216  of the housing  202  for promoting and maintaining contact between the ring  204  and the skin surface of the auricle  30 . A removable film, such as the film  22  described above, may be used to protect such adhesive or other attachment medium prior to placement of the electrode assemblies  200 . 
     The electrical conductors  208 ,  212  of the hybrid electrode assemblies  200 A- 200 D are electrically coupled to the electrical circuitry  14  similarly as illustrated in  FIG. 1 , although electrical control of the device  10 ′ differs from that of the devices  10 ,  100  in that the electrical circuitry  14  in the device  10 ′ has independent control of each of two electrode structures within each electrode assembly  200 A- 200 D. Example processes for controlling the hybrid electrode assemblies  200 A- 200 D will be described in detail below. The electrical circuitry  14  may, as illustrated in  FIG. 3 , be attachable to the patient, e.g., behind the ear  32  or other location. In alternate embodiments, the electrical circuitry  14  may be housed in a suitable circuitry housing that may be carried by and/or be attached to the patient. 
     In the example illustrated in  FIGS. 10 and 11 , each hybrid electrode assembly  200 A- 200 D is connected to two insulated electrical conductors  208 ,  212 , as illustrated in  FIGS. 9A and 9B  and described above, for a total of eight electrical conductors. In  FIG. 11 , the electrical conductors  212  electrically coupled to the needle electrodes  210  are labeled A, C, E and G, and the electrical conductors  208  electrically coupled to the ring electrodes  204  are labeled B, D, F and H respectively. The electrical circuit  14  may be programmed or otherwise configured to selectively apply electrical stimulation signals, e.g., in the form of voltage or voltage differentials, to various combinations of the electrodes A-H, simultaneously, individually and/or sequentially and with any desired signal attributes as described above, for the purpose of causing corresponding currents to flow through the auricle  30  to provide therapy by stimulating at least one auricular nerve field within the auricle  30 . 
     In one embodiment, the electrical circuitry  14  is illustratively configured to selectively supply voltages/currents solely to the percutaneously inserted needle electrodes  210  during a first phase of electrical stimulation treatment followed by selectively supplying voltages/currents solely to the non-percutaneous ring electrodes  204  during a second phase of electrical stimulation treatment separate from the first phase. In some such embodiments, any number of first phase treatments may be carried out prior to conducting each second phase treatment and vice versa. In one particular example implementation, each first phase treatment is following by one second phase treatment. In another example implementation, two first phase treatments are conducted, followed by one second phase treatment, followed by two first phase treatments, and so forth. In yet another example implementation, three or four first phase treatments are conducted, followed by one second phase treatment, followed by three or four first phase treatments, and so forth. In any of the foregoing examples, alternate implementations may include conducting two or more second phase treatments between each one or more first phase treatments. In still other alternate embodiments, multiple second phase treatments may conducted between each single first phase treatment. Those skilled in the art will recognize other treatment combinations, and it will be understood that all such other combinations are intended to fall within the scope of this disclosure. 
     An example therapy sequence of electrical stimulation signals applied by the circuitry  14  to the electrodes A-H during successive first and second phase treatment sequences are the following, although those skilled in the art will recognize that these treatment sequences represent only one of many different possible sequence combinations and therapy approaches that may be implemented using the device  10 ′. It will be understood that all such different sequence combinations and/or therapy approaches implementable using the device  10 ′ are intended to fall within the scope of this disclosure. 
     Example Therapy Sequence 
     First Phase Treatment: 
     The following example first phase treatment sequence utilizes only the needle electrodes A, C, E and G, with an arbitrary one of the needle electrodes A, C, E and G used as a ground or reference electrode. In this example, needle electrode G will be used as the reference electrode, although it will be understood that the reference electrode in other therapy sequences and/or in other instances of the first phase treatment in this example therapy sequence may be any of the other needle electrodes A, C and E. The following pattern of items 1-8 is illustratively repeated sequentially for P time units with a rest or pause time of Q time units following repeated execution of the pattern of items 1-8 for P time units. 
     1. Apply S volts simultaneously to A, C and E at T hertz for U time units. 
     2. Rest or pause V time units. 
     3. Apply S volts simultaneously to A, C and E at W hertz for U time units. 
     4. Rest or pause V time units. 
     5. Apply −S volts simultaneously to A, C and E at T hertz for U time units. 
     6. Rest or pause V time units. 
     7 Apply −S volts simultaneously to A, C and E at W hertz for U time units. 
     8. Rest or pause V time units. 
     Example values of variables P-W are the following, although it will be understood that in other implementations one or more of P-W may take on different values: 
     P=15 minutes. 
     Q=2 minutes. 
     S=3.2 volts. 
     T=1 Hz. 
     U=1 millisecond. 
     V=2 seconds. 
     W=10 Hz. 
     It will be further understood that in some embodiments one or more of the items 1-8 may be omitted and/or executed at a different point in the pattern, such that the sequential pattern may include any combination of any of items 1-8 executed in any order. 
     Second Phase Treatment: 
     The following second phase treatment sequence utilizes only the ring electrodes B, D, F and H, which will assume the use of two ground reference-decoupled gating circuits controllable to selectively apply voltages and voltage differentials to the electrodes B, D, F and H as illustrated in  FIG. 6  with respect to electrodes A, B, C and D thereof. In this regard, gating combination 1 refers to a positive voltage applied by VG 1  between electrodes B and D, and a separate (i.e., decoupled) positive voltage simultaneously applied by VG 2  between electrodes E and F, gating combination 2 refers to gating combination 1 with the polarities of VG 1  and VG 2  reversed, gating combination 3 refers to a positive voltage applied by VG 1  between electrodes B and H, and a separate (i.e., decoupled) positive voltage simultaneously applied by VG 2  between electrodes F and D, and gating combination 4 refers to gating combination 3 with the polarities of VG 1  and VG 2  reversed. 
     The following pattern of items 1-16 is illustratively repeated sequentially for P time units with a rest or pause time between each repeated pattern (in which no electrical stimulation signals are applied) of Q time units. 
     1. Apply S volts according to combination 1 at T hertz for U time units. 
     2. Rest or pause V time units. 
     3. Apply S volts according to combination 2 at T hertz for U time units. 
     4. Rest or pause V time units. 
     5. Apply S volts according to combination 1 at W hertz for U time units. 
     6. Rest or pause V time units. 
     7 Apply S volts according to combination 2 at W hertz for U time units. 
     8. Rest or pause V time units. 
     9. Apply S volts according to combination 3 at T hertz for U time units. 
     10. Rest or pause V time units. 
     11. Apply S volts according to combination 4 at T hertz for U time units. 
     12. Rest or pause V time units. 
     13. Apply S volts according to combination 3 at W hertz for U time units. 
     14. Rest or pause V time units. 
     15. Apply S volts according to combination 4 at W hertz for U time units. 
     16. Rest or pause V time units. 
     Example values of variables P-W are the following, although it will be understood that in other implementations one or more of P-W may take on different values: 
     P=15 minutes. 
     Q=1 minute. 
     S=4.2 volts. 
     T=1 Hz. 
     U=1 millisecond. 
     V=2 seconds. 
     W=10 Hz. 
     It will be further understood that in some embodiments one or more of the items 1-16 may be omitted and/or executed at a different point in the pattern, such that the sequential pattern may include any combination of any of items 1-16 executed in any order. In any case, a sequence of one or more cycles of the first phase treatment followed by one or more cycles of the second phase treatment is illustratively carried out over a time period of 120 hours, after which the therapy is discontinued. In one non-limiting example implementation, at least 2 sequences of the first phase treatment are carried out between each second phase treatment. In some alternate embodiments, the voltage applied between electrodes B and H in any or all of steps 9, 11, 13 and 15 may have a different frequency than the voltage applied between electrodes F and D so as to establish an interferential current in a space within the auricle  30  intersected by the two currents flowing between the pairs B, H and F, D of the four electrodes B, H, F and D. 
     Fourth Embodiment 
     The third embodiment of the auricular nerve field stimulation device  10 ′ is illustrated in  FIGS. 9A-11  and described above as including eight electrodes A-H each with a separate, dedicated electrical conductor connected to the electrical circuitry  14  such that the electrical circuitry  14  has independent control of each electrode A-H. In a fourth embodiment  10 ″, in contrast, the ring electrode  204  of each electrode assembly  200 A′- 200 D′ is electrically connected to the needle electrode  210  thereof, as illustrated by example in  FIG. 12 . Such connections may illustratively be made within the housing(s)  202 ,  208  or outside of the housing(s)  202 ,  208  adjacent thereto, and in either case only a single electrical conductor extends between the electrical circuitry  14  and each of the electrode assemblies  200 A′- 200 D′. In the embodiment illustrated in  FIG. 12 , electrical signals applied to the electrode assemblies  200 A′- 200 D′ are simultaneously applied to each electrode  204 ,  210  thereof. In this regard, conducting the first phase treatment described above not only provides percutaneous therapy via the needle electrodes  210  as described above, but further simultaneously provides conventional TENS therapy via the ring electrodes  204 . Similarly, conducting the second phase treatment described above not only provides second phase treatment therapy via the ring electrodes  204  as described above, but further simultaneously provides focused second phase treatment therapy via the percutaneously inserted needle electrodes  210 . It will be understood that further alternate embodiments are contemplated in which the ring electrode(s)  204  is/are electrically connected to the needle electrode(s)  210  in fewer than all of the electrode assemblies  200 A′- 200 D′, e.g., only in one or more of the electrode assemblies  200 A′- 200 D′. 
     While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such an illustration and description is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments have been shown and described and that all changes and modifications consistent with the disclosure and recited claims are desired to be protected.