Abstract:
Stimulation of the facial nerve system (e.g., electrically, electromagnetically, etc.) in stroke patients will cause dilation of occluded arteries and dilation of surrounding arteries, allowing for blood flow to circumvent the obstruction and reach previously-deprived tissue. The device approaches the facial nerve and its branches in the vicinity of the ear. In use, the device can be inserted into the ear canal or placed in proximity to the ear in order to stimulate the facial nerve system without puncturing the tympanic membrane (e.g., using an electromagnetic field). The device can also be advanced into the middle ear through a puncture created in the tympanic membrane. Branches of the facial nerve in the middle ear can then be stimulated directly (e.g., by application of electrical current). The device can be used in the emergency treatment of acute stroke or as chronically-implanted/inserted variations for long-term maintenance of blood flow to the brain and stroke prevention.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/397,462 filed on Jun. 14, 2010, entitled “Apparatus and Means of Use for Modulating the Function of Neural Structures within and near to the Middle Ear,” and of U.S. Provisional Application No. 61/330,366 filed on May 2, 2010, entitled “Apparatus and Means of Use for Modulating the Function the Tympanic Plexus, Geniculate Ganglion, Facial Nerve and/or Related Neural Structures of the Middle Ear,” the entire disclosures of which are hereby incorporated by reference herein in their entireties for all purposes. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to apparatuses and methods for treatment of conditions of the cranial vasculature, and more specifically to modulating function of particular neural structures in the vicinity of the ear for treatment of stroke and other conditions. 
     2. Description of the Related Art 
     Stroke is the most common cause of physical disability and the third most common cause of death in the United States. Nearly 900,000 cases of stroke occur each year in the United States, costing $69 billion in healthcare costs. Worldwide, there are nearly 15 million cases of stroke annually; the cost of healthcare services and lost productivity on such a scale is incalculable. Most cases of stroke are caused by loss of blood flow to the brain because of occlusion of a cerebral artery or carotid artery. Cerebral artery occlusion commonly results from (1) a blood clot that is carried by the blood flow into an artery in which it becomes lodged or (2) by formation of a blood clot upon an area of atherosclerotic plaque inside the artery. Loss of blood flow by either mechanism, or by any of several less-common mechanisms, deprives areas of the brain fed by the artery of nutrients and oxygen, leading to cell death and tissue necrosis. 
     The emergency treatment of stroke is limited. Only one drug, the thrombolytic tissue plasminogen activator (Alteplase), has been approved for the treatment of acute stroke in the United States. Alteplase acts to dissolve blood clots such as those that occlude cerebral and carotid arteries, causing stroke. As a result, Alteplase can also cause severe intracranial hemorrhage, which is its most serious complication. In order to reduce the chance of intracranial hemorrhage, Alteplase is subject to numerous restrictions that ultimately limit its use to only about 3% of all stroke patients. 
     In addition to Alteplase, endovascular techniques employing intra-arterial catheters are used to treat acute stroke. Endovascular techniques, based largely on retrieval of the blood clot from the cerebral or carotid artery or else local administration of thrombolytic drugs onto the blood clot, are costly and dangerous, and their use is limited to large hospitals that have highly-trained endovascular physicians on staff. Accordingly, only several thousand stroke patients appear to be treated with endovascular techniques each year in the United States. 
     A possible treatment of stroke that is currently under development is electrical stimulation of the sphenopalatine ganglion. This potential treatment involves placement of a stimulator rod through the roof of the mouth (hard palate) into the vidian canal, which leads to the sphenopalatine ganglion. This device and method has a number of drawbacks. By inserting the stimulator rod through the mouth into the vidian canal, there is a risk of introducing dangerous oral bacteria into the bones of the face. In addition, the blind insertion of the stimulator rod into the confines of the vidian canal (which not only leads to the sphenopalatine ganglion but also contains the vidian artery and nerve) of the hard palate risks inducing bleeding or direct nerve injury. Furthermore, placement of the stimulator rod requires specialized training and equipment. An additional concern associated with this method is that stroke patients commonly have difficulty swallowing as part of their neurological injury. Procedures requiring implantation of foreign bodies in the mouth, as required by this method, may lead to aspiration injury in patients with airways already compromised by the neurological injury from stroke. Finally, this device and method only stimulates the sphenopalatine ganglion and its immediate connections, which in animals has a small effect on blood flow to the brain. In comparison, stimulation of the entire facial nerve—which activates the sphenopalatine ganglion as well as several other nerves and ganglia—has a much more profound effect on blood flow to the brain. 
     Because of the magnitude of the disease and the limited treatments for it, a significant unmet medical need exists in acute stroke. Thus, there is a need for a solution that solves the problems with current acute stroke treatments noted above, and that: (a) does not cause intracranial hemorrhage, aspiration injury, bleeding and nerve injury in the vidian canal, or facial bone infection; (b) does not require highly-trained endovascular physicians or specialized training for use; and (c) can be placed under direct visualization or else is non- or minimally-invasive. 
     SUMMARY OF THE INVENTION 
     Disclosed herein is a medical device and method that solves the above problems and that improves blood flow to the brain by causing dilation of the cerebral and carotid arteries using the body&#39;s own neural regulation of the vasculature. The invention is an apparatus and method for modulating function of particular neural structures located within the vicinity of the ear for treatment of stroke and other conditions. In one embodiment, the medical device is a stimulator that causes dilation (relaxation) of the cerebral arteries. The cerebral and carotid arteries are innervated by nerves originating in the brainstem (“cranial nerves”), one of which—the facial nerve (also known as the 7 th  cranial nerve)—acts to dilate those arteries. Stimulation of the facial nerve in stroke patients may then cause dilation of the arteries supplying the brain and the head, allowing for blood flow to circumvent an obstruction and reach previously deprived brain tissue. 
     The device approaches the facial nerve and its branches as they pass through and near to the ear. In one embodiment, the device can be inserted into the ear canal, and it stimulates the facial nerve system without puncturing the ear drum (primary position) using stimulating energy such as an electromagnetic field. The device can also be advanced into the middle ear through an incision created in the ear drum (secondary position), and branches of the facial nerve in the middle ear can then be directly stimulated by application of electrical current. The device can be used in the emergency treatment of acute stroke or can be used as a chronically-implanted/inserted device for long-term maintenance of blood flow to the brain, e.g., in people with atherosclerotic disease of the cerebral vasculature in whom blood flow to parts of the brain is chronically compromised. 
     The invention can include a number of different aspects. In one aspect, the invention is an apparatus that comprises an insulating guide sheath having a proximal and a distal end. The insulating guide sheath is moveable into and out of the ear of a mammalian subject. The apparatus also includes an electrode having a proximal end and a distal tip. The electrode can be moveably disposed within the insulating guide sheath and can be placed in proximity to the tympanic membrane (ear drum) of the ear. The distal tip of the electrode can be disposed for translation within the insulating guide sheath and either (a) up to the distal end of the insulating guide sheath, but remaining inside the insulating guide sheath (e.g., when using the apparatus with the electrode positioned in the external ear) or (b) out of the distal end of the insulating guide sheath to be exposed (e.g., when using the apparatus with the electrode positioned in the middle ear). The apparatus also comprises a stimulus generator in electrical communication/direct connection with the electrode for supplying stimulus energy to the electrode for stimulating one or more components of the facial nerve system in the vicinity of the ear. In some embodiments, the stimulus generator is attached to an electrode that delivers stimulus energy, whereas in other embodiments the stimulus generator also serves as the electrode. The apparatus also includes a power source in electrical communication with the stimulus generator for providing power to the stimulus generator for supplying the stimulus energy to the electrode. 
     In another aspect, the invention is a method that comprises a step of moving an insulating guide sheath, having a proximal and a distal end, into the ear of a mammalian subject and a step of moving an electrode, having a proximal end and a distal tip, within the insulating guide sheath. The method also includes a step of translating the distal tip of the electrode up to the distal end of the insulating guide sheath or out of the distal end of the insulating guide sheath via the movement of the electrode to place the distal tip in proximity to the tympanic membrane of the ear. The method also includes stabilizing the insulating guide sheath to hold the insulating guide sheath in place within the ear. The method further includes supplying stimulus energy to the electrode to stimulate one or more components of the facial nerve system in the vicinity of the ear. 
     In a further aspect, the invention is a chronic method that comprises a step of inserting or implanting a chronic treatment device into the ear of a mammalian subject. The chronic treatment device can comprise an insulating guide sheath containing an electrode. The chronic treatment device can be inserted or implanted in proximity to the course of the facial nerve system through the temporal bone. The method also includes supplying stimulus energy to the electrode over a period of time to chronically stimulate one or more components of the facial nerve system in the vicinity of the temporal bone. The method further includes providing power via a power source for supplying the stimulus energy to the electrode. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description and accompanying drawings where: 
         FIG. 1  depicts a side, cross-sectional view of the external and middle ear with surrounding structures, and the Figure illustrates an apparatus for modulation of the function of the facial nerve system in the primary position, according to an embodiment of the invention. 
         FIG. 2  depicts a side, cross-sectional view of the ear (enlargement of  FIG. 1 ) including stimulation by the apparatus in the primary position, according to an embodiment of the invention. 
         FIG. 3  depicts a side, cross-sectional view of the external and middle ear with surrounding structures, and the Figure illustrates the apparatus for modulation of the function of the facial nerve system in the secondary position, according to an embodiment of the invention. 
         FIG. 4  depicts a side, cross-sectional view of the ear (enlargement of  FIG. 3 ) including stimulation by the apparatus in the secondary position, according to an embodiment of the invention. 
         FIG. 5 a    depicts a side, cross-sectional view of the electrode of  FIG. 2  configured as a wire coil, according to an embodiment of the invention. 
         FIG. 5 b    depicts a side, cross-sectional view of the electrode of  FIG. 2  configured as a series of arcs, according to an embodiment of the invention. 
         FIG. 5 c    depicts a side, cross-sectional view of the electrode of  FIG. 2  configured as series of circles, according to an embodiment of the invention. 
         FIG. 6 a    depicts a side, cross-sectional view of the apparatus demonstrating multiple interchangeable electrodes and the manner in which they connect to the stimulus generator. 
         FIG. 6 b    depicts a side, cross-sectional view (enlargement of  FIG. 6 a   ) showing separation of the two tips of a bipolar electrode caused by flexible bends near the distal end of the wires of a bipolar electrode, with the wires retracted within the insulating guide sheath, according to an embodiment of the invention. 
         FIG. 6 c    depicts a side, cross-sectional view of the bipolar electrode of  FIG. 6 b   , after incision of the tympanic membrane where the electrode enters the middle ear and the electrode wires are extended out of the insulating guide sheath, according to an embodiment of the invention. 
         FIG. 7 a    depicts a side, cross-sectional view of the distal tip of the apparatus having an insulating plug that is within the insulating guide sheath, according to an embodiment of the invention. 
         FIG. 7 b    depicts a side, cross-sectional view of the distal tip of the apparatus in  FIG. 7 a    with the insulating plug after incision of the tympanic membrane, where the electrode enters the middle ear and pushes the insulating plug out, according to an embodiment of the invention. 
         FIG. 7 c    depicts a side, cross-sectional view of the distal tip of the apparatus with an annulus where the electrode is within the insulating guide sheath, according to an embodiment of the invention. 
         FIG. 7 d    depicts a side, cross-sectional view of the distal tip of the apparatus of  FIG. 7 c    with the annulus after incision of the tympanic membrane, where the electrode enters the middle ear and perforates the annulus, according to an embodiment of the invention. 
         FIG. 7 e    depicts a side, cross-sectional view of the distal tip of the apparatus with the flower tip having the leaves closed and the electrode within the insulating guide sheath, according to an embodiment of the invention. 
         FIG. 7 f    depicts a side, cross-sectional view of the distal tip of the apparatus of  FIG. 7 e    with a flower tip having the leaves open after lancing the tympanic membrane, where the electrode enters the middle ear and forces open the closed tip, according to an embodiment of the invention. 
         FIG. 8  depicts a side view of a speculum for use with the apparatus, according to an embodiment of the invention. 
         FIG. 9  depicts a side, cross-sectional view of an ear piece of the apparatus with a stimulus generator placed on the external ear and an insulating guide sheath containing the electrode that are insertable into the ear canal, where the apparatus includes a wireless transmitter and receiver, according to an embodiment of the invention. 
         FIG. 10  depicts a side, cross-sectional view of an ear piece of the apparatus with a stimulus generator placed on the external ear and an insulating guide sheath containing the electrode that are insertable into the ear canal, where the ear piece connects to the power source, according to an embodiment of the invention. 
         FIG. 11 a    depicts a side, cross-sectional view of an ear piece of the apparatus in which an electromagnetic coil forms the stimulus generator placed on the external ear, in which a guide piece positions the device over the ear canal, according to an embodiment of the invention. 
         FIG. 11 b    depicts an ear piece of the apparatus that positions an electromagnetic coil in a manner offset from the ear canal, according to an embodiment of the invention. 
         FIG. 12 a    depicts a side, cross-sectional view of an electromagnetic coil cylinder of the apparatus that is positioned in the ear canal by its form-fitting shape, according to an embodiment of the invention. 
         FIG. 12 b    depicts the electromagnetic coil cylinder of  FIG. 12 a    with a ferromagnetic bar placed through its lumen and into the middle ear space, according to an embodiment of the invention. 
         FIG. 12 c    depicts a side, cross-sectional view of the ear (enlargement of  FIG. 12 b   ) including stimulation by the ferromagnetic bar, according to an embodiment of the invention. 
         FIG. 13  depicts a side, cross-sectional view of a stimulator device for chronic modulation of the facial nerve system implanted into the bones of the skull, according to an embodiment of the invention. 
         FIG. 14  depicts a side, cross-sectional view of a stimulator device for chronic modulation of the facial nerve system placed into the middle ear, according to an embodiment of the invention. 
         FIG. 15  is a flow diagram illustrating a method for stimulation of neural structures, according to an embodiment of the invention. 
         FIG. 16  is a flow diagram illustrating another method for stimulation of neural structures, according to an embodiment of the invention. 
         FIG. 17  is a flow diagram illustrating a continuation of the method for stimulation of neural structures of  FIG. 16 , according to an embodiment of the invention. 
         FIG. 18  is a flow diagram illustrating a chronic method for stimulation of neural structures, according to an embodiment of the invention. 
     
    
    
     The skilled artisan will understand that the drawings are for illustration purposes only. The drawings are not intended to limit the scope of the present teachings in any way. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Neural Structure Modulation Apparatus 
     The purpose of stimulation of the facial nerve system by the apparatus is to modulate the cranial blood flow. Modulation of the cranial blood flow includes increasing, decreasing, redistributing, or otherwise changing blood flow to the cerebral, carotid, and/or extracerebral arteries, including but not limited to the arteries of the brain, brainstem, face, scalp, eyes, and neck. In some embodiments, the apparatus stimulates the facial nerve system in order to increase blood flow to the brain of the subject for treatment of a stroke or to enhance delivery of a blood-borne pharmacologic agent to treat a condition of the subject. In other embodiments, blood flow to the brain or other parts of the head is decreased. As used herein, the term stroke refers to any type of stroke, and the phrase “stroke caused by atherosclerotic disease” refers specifically to stroke caused by atherosclerotic cerebral artery disease, which includes about 20% of all stroke. 
       FIG. 1  depicts a side view of the apparatus  100  for treatment of conditions of the cerebral vasculature in which stimulation of part or all of the facial nerve system is accomplished through the ear, according to an embodiment of the invention.  FIG. 1  illustrates various components of the ear, including the external ear  114 , the middle ear  116 , the inner ear  118 , the tympanic membrane  136  (ear drum), and the Eustachian tube  120 . As used herein, the term “ear” refers to any portion of the ear, including the external, middle, and inner ear, unless otherwise specified.  FIG. 1  also illustrates certain components of the nervous system including the facial nerve  124  and a branch  126  of the facial nerve passing through the middle ear  116 . The term “facial nerve system” as used herein includes, but is not limited to, the facial nerve, the geniculate ganglion, the tympanic plexus, the sphenopalatine nerves and ganglion, the petrosal nerves, the ethmoidal nerves, the palatine nerves, the vidian nerve, the communicating branches and connections of the aforementioned structures, and the communicating branches and connections between any of the aforementioned structures and the trigeminal, glossopharyngeal, or vagal nerves. These components of the facial nerve system are in the vicinity of, in proximity to, or are proximate to the ear  136 . In some embodiments, the apparatus stimulates components of the facial nerve system that pass through, have a portion or branch within, or contribute to a structure within the middle ear  116 . Furthermore, in some embodiments, the apparatus stimulates components of the facial nerve system that have a portion or branch within the middle ear  116  or that are immediately outside the middle ear  116 . As used herein, the term “limited facial nerve system” includes the nerves listed above, but not including the sphenopalatine nerves and ganglion, the petrosal nerves and communicating branches thereof, the ethmoidal nerves and communicating branches thereof, the palatine nerves including nasopalatine nerves, the vidian nerve and communicating branches thereof, and communicating branches between any of the aforementioned structures and the trigeminal nerve system. 
     The apparatus  100  shown in  FIG. 1  includes various components. The apparatus  100  includes an insulating guide sheath  104  having a proximal end  103  (end closest to the stimulus generator  106  and closest to the operator of the device) and a distal end  105  (end inside the ear, farthest from the operator of the device and stimulus generator). The insulating guide sheath  104  is moveable into and out of the ear (e.g., of a mammalian subject). As used herein, the term “mammalian subject” or “subject” refers to any mammal, including humans. In some embodiments, the insulating guide sheath  104  is rigid or substantially rigid (i.e., sufficiently rigid for translation into the ear but not inflexible) and is insertable into the ear via pressure or pushing of the proximal end  103  of the insulating guide sheath  104  to translate the distal tip  132  into the ear. The apparatus  100  also includes an electrode  102  that also has a proximal end  131  and a distal tip  132 . As used herein, the term “electrode” includes a stimulation device that provides stimulation, such as stimulation or stimulus energy in the form of an electric current or in the form of an electromagnetic or magnetic field. In some embodiments, the electrode  102  is housed within the insulating guide sheath  104 . In some embodiments, the electrode  102  is a straight wire or plurality of wires. In some embodiments, the electrode  102  is a coiled wire or wire formed into a non-linear shape. In some embodiments, the electrode  102  and insulating guide sheath  104  together form a stimulator. In further embodiments, the distal tip  132  of the electrode  102  is detachable from the electrode  102  and is replaceable with a plurality of different distal tips that are attachable to the electrode  102 . Thus, the apparatus  100  can be reused with new/clean distal tips  132  if desired or if the type of stimulation (e.g., electrical, electromagnetic) delivered by the electrode  102  is to be changed. 
     In the apparatus  100  shown in  FIG. 1 , the insulating guide sheath  104  is moveably disposed within the ear and the electrode  102  is moveably disposed within the insulating guide sheath  104 . In some embodiments, the electrode  102  and insulating guide sheath  104  are advanced together into the ear. In other embodiments, the insulating guide sheath  104  is advanced into the ear first, and the electrode  102  is advanced within the insulating guide sheath  104  and into the ear. In some embodiments, the distal tip  132  of the electrode  102  can be advanced up to the distal end  105  of the insulating guide sheath  104 . In some embodiments, the distal tip  132  is further advanced out of the distal end  105  of the insulating guide sheath  104  so that the distal tip  132  is exposed. 
     There are two positions for the apparatus  100 , as follows: the primary position and the secondary position.  FIG. 1  illustrates the primary position and  FIG. 3  illustrates the secondary position. For the primary position, the electrode  102  and the insulating guide sheath  104  are advanced into the ear canal  122  near to the tympanic membrane  136 , and the electrode  102  is disposed to remain inside the insulating guide sheath  104  (or the electrode tip can be translated out of the insulating guide sheath  104  and exposed, if desired). In the primary position, the electrode  102  remains external to the tympanic membrane  136 , and so remains within the ear canal  122 . For the secondary position, the distal tip  132  of the electrode  102  is disposed for translation out of the distal end  105  of the insulating guide sheath  104  to be exposed (or it can be kept within the insulating guide sheath  104  if desired) and placed in proximity to a tympanic membrane  136  of the ear. Thus, the insulating guide sheath  104  and electrode  102  are passed into the middle ear  116 , and so are positioned internal to the tympanic membrane  136 . In this situation, the tympanic membrane  136  is incised or punctured to insert the insulating guide sheath  104  and electrode  102  through the incised tympanic membrane  136  and into the middle ear  116 . The tympanic membrane  136  can be incised in various ways. In one embodiment, the distal end  105  of the insulating guide sheath  104  is sharp, and this sharpened distal tip can be pushed through the tympanic membrane  136  to create an opening to reach the middle ear  116 . In other embodiments, a separate instrument can be used to make an incision in the tympanic membrane  136 . According to some embodiments, both the insulating guide sheath  104  and electrode  102  are inserted into the middle ear  116 . According to other embodiments, only the electrode  102  is inserted into the middle ear  116  while the insulating guide sheath  104  remains in the ear canal  122 . In some embodiments, the insulating guide sheath  104  is between 6 cm and 12 cm in length in order to allow access to the middle ear  116  through the ear canal  122 . 
     Once the insulating guide sheath  104  is in place within the ear, it can be fixed into position to prevent unintended movement. In one embodiment, the insulating guide sheath  104  is fixed into position by inflation of an inflatable cuff  134  on the insulating guide sheath  104  in the ear canal  122 , though other stabilization mechanisms can also be used, including stabilization with an ear piece or clip fixed to the external ear  114  (not shown). In some embodiments, the inflatable cuff  134  is attached to the outer wall of the insulating guide sheath  104  and the inflatable cuff  134  is configured to fit against a surface of the ear for holding the insulating guide sheath  104  in place within the ear. The inflatable cuff  134  can be used to fix the insulating guide sheath  104  into the primary position or the secondary position. 
     A stimulus generator  106  can be in electrical communication with the electrode in  102  various ways. For example, the stimulus generator  106  can be directly connected to the electrode  102  (e.g., connected via one or more wires or other connectors), or indirectly connected to or in communication with the electrode  102 . A power source  108  can be placed in electrical communication with the stimulus generator  106  for providing power to the stimulus generator  106  for supplying the stimulus energy to the electrode  102 . The power source  108  can also be directly or indirectly connected to the stimulus generator  106 . For example, the power source  108  can connect to the stimulus generator  106  via one or more wires or other connectors, but the power source  108  can also indirectly connect to or be in communication with the stimulus generator  106 , such as via a wireless communication method. In some embodiments, the power source  108  provides power to the stimulus generator  106 , and the stimulus generator  106  provides stimulus energy to the electrode  102  that then provides stimulation to one or more aspects of the facial nerve system. 
     In addition, the apparatus  100  can include an electrode advancer  110  to which the proximal end  131  of the electrode  102  is attached or associated. The electrode advancer  110  can include an advancement mechanism for advancing the electrode  102  within the insulating guide sheath  104  and/or for advancing the insulating guide sheath  104  into the ear. 
     While  FIGS. 1-4  show the insulating guide sheath  104  and electrode  102  being inserted into the ear via the ear canal  122 , these components can be also configured for insertion into the middle ear  116  via a Eustachian tube  120  of the subject. Various disease processes in the ear canal or upon the tympanic membrane may impair access of medical devices through the ear canal. To overcome limited access through the ear canal  122 , an apparatus capable of accessing the middle ear through the Eustachian tube  120  can be employed. The Eustachian tube  120  connects the middle ear  116  with the nasopharynx, allowing for pressure equilibration between the middle ear  116  and the external environment and for drainage from the middle ear  116  to enter the throat. The insulating guide sheath  104  and electrode  102  can be inserted into the Eustachian tube  120  without direct visualization through transnasal positioning, under direct visualization transnasally, or under direct visualization transorally. The insulating guide sheath  104  and electrode  102  can then be advanced along the Eustachian tube  120  and into the middle ear  116 . In some embodiments, the insulating guide sheath  104  is between 20 cm and 30 cm in length in order to allow access to the middle ear  116  through the Eustachian tube  120 . Once placed in the middle ear  116  through the Eustachian tube  120 , the apparatus  100  can then be used as explained above, i.e., to apply stimulus energy to one or more components of the facial nerve system for stroke treatment, etc. 
     Filling of the ear canal, or of the middle ear, with electrically-conductive material, gel, or solution may be used to achieve the desired result of the invention. Thus, in some embodiments, the apparatus  100  further includes an injection port  112  connected to the insulating guide sheath  104 . The injection port  112  can be a tube or other structure attached to an opening in the wall of the insulating guide sheath  104 . The injection port  112  can include an opening on one end into which the user can insert a material, gel, or solution. The injection port  112  is used for injecting into the insulating guide sheath  104  a material, gel, or solution to facilitate treatment of the subject. The material, gel, or solution is contained within the insulating guide sheath  104  following injection, and in some embodiments, some or all of the material, gel, or solution is transferred through the insulating guide sheath  104  for release from the distal end  105  of the insulating guide sheath  104 . A variety of different materials, gels, or solutions can be placed into the lumen of the insulating guide sheath through the injection port  112 . For example, an electrically-conductive gel or solution can be injected into an ear canal  122  or middle ear  116  of the subject to increase conductivity. As another example, an anesthetic or other pharmacological agent used to eliminate an unwanted response of tissue local to the electrode  102  can be injected into an ear canal  122  or middle ear  116 . The pharmacological agent can also be added to the conductive material, gel, or solution. In some embodiments, the injection port  112  connects into a single lumen within the insulating guide sheath  104 . In other embodiments, the injection port  112  connects into one of a plurality of lumens within the insulating guide sheath  104 . 
     In some embodiments, the apparatus  100  further includes a stimulus controller  140  attached to the stimulus generator  106  for adjusting the stimulus energy applied to the electrode  102 . The stimulus controller  140  can include a user interface by which the operator of the apparatus can provide instructions to or otherwise interact with the apparatus  100 . The stimulus controller  140  can allow the operator to control the strength, frequency, and/or other parameters of the stimulus energy. For example, the controller  140  can include particular controls (e.g., knobs, digital settings, etc.) for increasing or decreasing the strength of the current and controlling various other factors in the operation of the apparatus  100 . Where the apparatus  100  is connectable to a computer or other machinery, the operator may also be able to interact with and control the apparatus  100  via the interface of the computer, including tracking the subject&#39;s vital signs, responses to the stimulus energy over time, and so forth. 
     The stimulus controller  140  can further be used to adjust the stimulus energy for various purposes. For example, the stimulus energy can be adjusted based on one or more physiological or pathophysiological responses of the subject to the stimulus energy (e.g., taste sensation; audition; lacrimation; nasal drainage; nasal congestion; salivation; sound sensitivity; face, head, or hand movements; speech production or arrest; sensation of body movement; eye movements; cranial blood flow; direct or indirect activity of a nerve; and severity of neurological dysfunction of the subject). For example, if the subject exhibits certain eye movements, the operator can observe this and respond to this by changing the stimulus energy or certain other parameters associated with the stimulus energy. As another example, the apparatus  100  itself can determine or interact with other instrumentation to detect certain physiological or pathophysiological responses of the subject to the stimulus energy, and the apparatus  100  can automatically adjust the stimulus energy in response. As a further example, the stimulus energy can be adjusted to increase or otherwise control blood flow to the brain of the subject as either the direct treatment of a disease process or else to facilitate the delivery of blood-borne pharmacologic agents as the treatment of a disease process. 
     The apparatus  100  also includes a stimulus generator  106  in electrical communication with the electrode  102  for supplying stimulus energy to the electrode  102  for stimulating one or more components of the facial nerve system. In some embodiments, the stimulus energy is electrical current applied through the electrode  102  that creates an electromagnetic field  202  that is of sufficient strength to stimulate one or more components of the facial nerve system located in the vicinity of the ear.  FIG. 2  illustrates the insulating guide sheath  104  and electrode  102  in the primary position, and further illustrates application of the stimulus energy, according to an embodiment of the invention. In this embodiment, the stimulus energy is electrical current applied to the electrode  102  in order to create an electromagnetic field  202  that is of sufficient strength to stimulate one or more components of the facial nerve system located in, or in the vicinity of, the middle ear  116 . Thus, the electromagnetic field  202  is used to stimulate the facial nerve system with the electrode  102  being in the ear canal  122 , on the external side of the tympanic membrane  136 . In some embodiments, the electromagnetic field  202  is defined by various combinations of the following parameters: a stimulation frequency ranging from 0.01 to 100 Hz; a field strength of 0.01 to 5.0 Tesla; a biphasic or oscillatory waveform. In some embodiments, the electromagnetic field  202  is applied intermittently or periodically. In some embodiments, stimulation with certain parameters reduces or redirects blood flow to the brain. 
     In some embodiments, failure of the electrode to achieve the desired result when used in the primary position is followed by advancement of the electrode  102  into the middle ear  116  to put the apparatus  100  into the secondary position. In this situation, the tympanic membrane  136  is incised using the sharpened distal end  105  of the insulating guide sheath  104  or other mechanism for allowing the insulating guide sheath  104  and/or electrode  102  to enter the middle ear  116 . The insulating guide sheath  104  can be fixed into place in the ear canal  122  or advanced through the incision in the tympanic membrane  136  and then fixed into place, and the electrode  102  can be advanced past the distal end  105  of the insulating guide sheath  104  into the middle ear  116 . Electrical current can then be applied through the exposed tip of the electrode  102  in order to stimulate one or more components of the facial nerve system. This is referred to as the secondary position. In the secondary position, one or more components of the facial nerve present within the middle ear  116  can be subjected to stimulation by direct exposure to electrical current. In some embodiments, the electrode comprises a cathode and an anode. In one embodiment, the closest distance between the cathode and the anode is greater than the closest distance between any portion of the cathode and any portion of a tympanic plexus, facial nerve, or other neural structure of the middle ear. In some embodiments, the electrode is monopolar and a ground wire is applied to an external ear or other part of the head. 
       FIG. 3  illustrates the apparatus  100  in the secondary position, according to an embodiment of the invention. The insulating guide sheath  104  has been fixed into place by the inflatable cuff  134  in the ear canal  122 . The insulating guide sheath  104  has been used to incise the tympanic membrane  136 . The incision  302  (e.g., puncture hole) is illustrated in  FIG. 3  and the insulating guide sheath  104  and electrode  102  have been advanced through the incision  302  into the middle ear  116 . The electrode  102  has further been advanced within the insulating guide sheath  104  so that the distal tip  132  of the electrode  102  is exposed. In some embodiments, the distal tip  132  of the electrode  102  is positioned near a branch  126  of the facial nerve  124  that is passing through middle ear  116 . 
       FIG. 4  illustrates the apparatus  100  in the secondary position with the stimulus energy being applied to the electrode  102 .  FIG. 4  illustrates direct electrical stimulation  402  of a facial nerve branch  126  in the middle ear  116 . In some embodiments, the electrode is retained within the insulating guide sheath  104  and application of the electrical current to the electrode  102  creates an electromagnetic field  202  that penetrates various tissues in order to stimulate components of the facial nerve system. In some embodiments, the electrical stimulation  402  is defined by various combinations of the following parameters: a stimulation frequency ranging from 0.1 to 100 Hz; a current of 0.1 to 5.0 mA; a biphasic waveform with or without a delay between the phases. In some embodiments, the electrical stimulation  402  is provided intermittently or periodically. In some embodiments, stimulation with certain parameters decreases or shunts off blood flow to the brain. 
       FIGS. 5 a - c    illustrate the distal tip  132  of the apparatus  100  used in the primary position, and further illustrate examples of various configurations of the distal tip  132  of the electrode  102  suitable for generating an electromagnetic field  202 .  FIG. 5 a    illustrates the distal tip  132  of the electrode  102  configured as a wire coil  504  with repeating loops that connects at one end to the electrode current inflow wire  502  and at the other end to the electrode current outflow wire  506 , according to an embodiment of the invention. The electrode current inflow wire  502  and electrode current outflow wire  506  are separated by an insulating septum  508  or other means of insulation within the lumen  512  of the insulating guide sheath  104 . In some embodiments, and as shown in  FIG. 5 a   , the wire coil  504  is positioned near the distal end  105  of the insulating guide sheath  104  with its axis largely parallel to the direction of the electrode wires. In other embodiments, the wire coil  504  is positioned within the lumen  512  of the insulating guide sheath  104  with its axis largely perpendicular to, or significantly angled away from, the direction of the electrode wires (not shown). In some embodiments, the wire coil  504  is tapered as is a cone. In some embodiments, the wire coil  504  has an outer diameter of less than 6 mm, an inner diameter of at least 2 mm, and a length of 10-30 mm. In some embodiments, the wire coil is coiled into 5-25 layers with 50-250 turns per layer. 
       FIG. 5 b    illustrates the distal tip  132  of an electrode  102  configured as one or more wire arcs  514 , according to an embodiment of the invention. As shown in  FIG. 5 b   , in some embodiments, a series of arcs are placed at the distal tip  132  of the electrode  102  between the electrode current inflow wire  502  and the electrode current outflow wire  506 , so as to form electrical connections between the electrode current inflow wire  502  and the electrode current outflow wire  506 . In some embodiments of the invention, the arcs are inclined from the plane formed by the electrode current inflow wire  502  and the electrode current outflow wire  506  within the lumen  512  of the insulating guide sheath  104 . In some embodiments, the distance between the electrode current inflow wire  502  and the electrode current outflow wire  506  is minimal, thereby pulling the wire arcs  514  into substantially noose-like shapes (not shown). In some embodiments, 4-50 wire arcs  514  are employed. 
       FIG. 5 c    illustrates the distal tip  132  of an electrode  102  configured as one or more wire circles  516 , according to an embodiment of the invention. In some embodiments, the wire circles  516  are placed between the electrode current inflow wire  502  and the electrode current outflow wire  506  so that the electrode current inflow wire  502  and the electrode current outflow wire  506  connect to the wire circles  516  at a single point. In some embodiments, the wire circles  516  are placed between the electrode current inflow wire  502  and the electrode current outflow wire  506  so that their planes are not perpendicular to the direction of the electrode current inflow wire  502  or the electrode current outflow wire  506 . In some embodiments, the wire circles  516  are distorted so that their shape is substantially oval. In some embodiments, the wire circles  516  are distorted so that all the points along the wire do not lie within a single plane (not shown). 
     Referring to  FIGS. 5 a - c   , the wire and insulating guide sheath  104  can be constructed in various ways. In some embodiments, the wire comprising the shapes illustrated in  FIGS. 5 a - c    is between 0.06-0.60 mm in diameter. In some embodiments of apparatus  100 , the insulating guide sheath  104  is composed of poly(4,4′-oxydiphenylene-pyromellitimide) (KAPTON®), polyimide, or polytetrafluoroethylene (PTFE or TEFLON®). In some embodiments, the insulating guide sheath  104  is prepared with a conformal coating. 
     Everything described above including the various embodiments of the distal tip of the electrode described in  FIGS. 5 a - c    can apply to the remaining designs, such as  FIGS. 6-14 . For example, the description of the sizes, shapes, designs, and materials used in the construction of the components of  FIGS. 5 a - c    can apply to the apparatus designs of  FIGS. 6-14 . However, for ease of presentation and clarity, these details are not repeated again below for each of  FIGS. 6-14 . 
       FIG. 6 a    illustrates an apparatus  600  that allows for exchange of electrodes for use in the primary and secondary positions, according to an embodiment of the invention. For use of an electromagnetic field stimulator in the primary position, a junction is formed by the union of a distal coupler  608  and proximal coupler  606 , in which the distal coupler  608  is in electrical communication with the electrode  102  at the proximal end  103  of the insulating guide sheath  104 , and in which the proximal coupler  606  is in communication with the stimulus generator  106 . Connection of the proximal coupler  606  and the distal coupler  608  places the electrode in electrical continuity with the stimulus generator  106  allowing stimuli to be delivered through the electrode that then generates an electromagnetic field  202 . For use in the secondary position, the electromagnetic field stimulator described above is removed by disconnection of the distal coupler  608  from the proximal coupler  606  specific for that stimulator type. Then, a stimulator type appropriate for the secondary position is attached, e.g., through a distinct junction. In this example, an electrode capable of delivering direct electrical stimulation through its uninsulated distal tip  132  is attached by means of a distal coupler  604  at the proximal end  131  of the electrode to a proximal coupler  602  on the stimulus generator  106 , wherein the distal coupler  604  and the proximal coupler  602  are specific for this type of electrode and are not typically used with other electrode types (e.g., those that generate electromagnetic fields). Connection of the proximal coupler  602  and the distal coupler  604  places the electrode in electrical continuity with the stimulus generator  106 , allowing stimuli to be delivered through the electrode and released from the distal tip  132  as direct electrical current or voltage. 
     In some embodiments, attachment of one electrode type by means of connection of the proximal coupler  602 , 606  to the distal coupler  604 , 608  prohibits the simultaneous attachment of another electrode type to the apparatus. In some embodiments, attachment of an electrode type by means of a proximal coupler  602 , 606  and a distal coupler  604 , 608  determines, adjusts, or limits the power delivered by the power source  108 . 
     In some embodiments, a bipolar electrode is used to deliver stimulation in the secondary position of the device, as shown in  FIG. 6 a   . In order to optimally orient the bipolar electrode within the middle ear  116  space, an electrode rotator  610  is positioned at or near the proximal end  131  of the electrode for use in the secondary position. The electrode rotator  610  is used to rotate one pole of the bipolar electrode around the second pole, or else to rotate both poles around a common axis, or to otherwise adjust the positioning of the electrode. In some embodiments, rotation of one or more of the electrode poles is achieved by rotating the insulating guide sheath  104  that houses the poles of the bipolar electrode. An electrode advancer  110  can also be attached at or near the proximal end of the bipolar electrode such that one or both poles of the bipolar electrode can be advanced from, or retracted into, the insulating guide sheath  104 . 
     As shown in  FIG. 6 b   , in some embodiments, a bipolar electrode is formed by a cathodic wire  506  and an anodic wire  502  that are housed within separate lumens within the insulating guide sheath  104 . In some embodiments, separate lumens are formed by an insulating septum  508  or other such division. In some embodiments, flexible bends  652  are placed in the electrode wire near the distal ends of the cathodic wire  626  and anodic wire  622 . As shown in  FIG. 6 c   , when the electrode wires are advanced out of the distal end  105 , the flexible bends  652  spread the tips of the electrode wires apart by a predetermined distance. In other embodiments, separate lumens within the insulating guide sheath  104  open at different positions along the length of the insulating guide sheath  104  so that a fixed distance exists between the cathodic wire  626  and anodic wire  622  once the wires are advanced out of the insulating guide sheath  104  (not shown). 
     The wire or wires of the electrode for use in the secondary position to deliver stimulation in the middle ear  116  is/are formed or constructed in various ways. In some embodiments, the wire or wires is/are formed from stainless steel, platinum, silver alloy, gold alloy, or nitinol. In some embodiments, the wire or wires of the electrode may be square or in a strip shape. In some embodiments, the wire or wires of the electrode may be capped at their distal ends so as to be non-traumatic once extended from the insulating guide sheath  104 . 
       FIGS. 7 a  and 7 b    illustrate the distal end  105  of the insulating guide sheath  104 , according to an embodiment of the invention.  FIG. 7 a    illustrates the electrode  102  within the hollow lumen  512  of the insulating guide sheath  104  for use in the primary position. The distal end  105  of the insulating guide sheath  104  includes a cutting edge  702  that is used to incise or create an opening in the tympanic membrane  136  through which the insulating guide sheath  104  and electrode  102  can be passed.  FIG. 7 a    further shows an insulating plug  706  attached to the distal tip  132  of the electrode  102 . The insulating plug  706  protects and insulates the distal tip  132  of the electrode  102 .  FIG. 7 a    shows the electrode retracted within the hollow lumen  512  of the insulating guide sheath  104 .  FIG. 7 b    shows the distal tip  132  of the electrode  102  extended from the hollow lumen  512  of the insulating guide sheath  104 . After incision of the tympanic membrane  136 , the electrode  102  pushes the insulating plug  706  out of the insulating guide sheath  104  and enters the middle ear  116 , achieving the secondary position. 
       FIGS. 7 c  and 7 d    illustrate the distal end  105  of the insulating guide sheath  104 , according to an embodiment of the invention.  FIG. 7 c    illustrates the electrode  102  within the hollow lumen  512  of the insulating guide sheath  104  for use in the primary position. Like the embodiment of  FIGS. 7 a  and 7 b   ,  FIGS. 7 c  and 7 d    illustrate an embodiment in which the distal end  105  of the insulating guide sheath  104  includes a cutting edge  702  that is used to incise the tympanic membrane  136  through which the insulating guide sheath  104  and electrode  102  can then be passed.  FIG. 7 c    further shows an intact annulus  708  and  FIG. 7 d    shows a perforated annulus  710 .  FIG. 7 c    shows the electrode retracted within the hollow lumen  512  of the insulating guide sheath  104 .  FIG. 7 d    shows the distal tip  132  of the electrode  102  extended from the hollow lumen  512  of the insulating guide sheath  104  through the annulus, causing perforation of the annulus. In other words, after incision of the tympanic membrane  136 , the electrode  102  perforates the annulus to insert the distal tip  132  of the electrode  102  into the middle ear  116 , achieving the secondary position. 
       FIGS. 7 e  and 7 f    illustrate the distal end  105  of the insulating guide sheath  104 , according to an embodiment of the invention.  FIG. 7 e    illustrates the electrode  102  within the hollow lumen  512  of the insulating guide sheath  104  for use in the primary position.  FIGS. 7 e  and 7 f    illustrate an embodiment in which the insulating guide sheath  104  includes a pointed tip  712  that is used to incise the tympanic membrane  136  through which the insulating guide sheath  104  and electrode  102  can be passed.  FIG. 7 e    shows the electrode  102  retracted within the hollow lumen  512  of the insulating guide sheath  104  and the closed end  714  of the insulating guide sheath  104 .  FIG. 7 f    shows the open end  716  of the insulating guide sheath  104 . The distal end  105  of the insulating guide sheath  104  in this embodiment includes three leaves (though more or fewer leaves can be included) that are moved apart to open the closed end  714 . Once open, the distal tip  132  of the electrode  102  is extended from the hollow lumen  512  of the insulating guide sheath  104 . Thus, after lancing the tympanic membrane  136 , the electrode  102  forces open the closed end  714  of the insulating guide sheath  104  and enters the middle ear  116 , achieving the secondary position. 
       FIG. 8  illustrates a speculum  800  for use with the apparatus  100 , according to an embodiment of the invention. Placement of the insulating guide sheath  104  and electrode  102  in the ear canal  122  or in the middle ear  116  may require a specialized otoscope speculum  800  that will allow for direct visualization of anatomical structures. The ear speculum  800  can be composed of a hollow, largely conical structure with openings at its proximal end  802  and distal end  804 . The speculum  800  can also be modified with a groove  806  or other peripheral channel along its lateral length, where the groove  806  or other peripheral channel is of sufficient size to accommodate the guide sheath  104 . In this embodiment, the groove  806  allows for lateral passage of the insulating guide sheath  104  and for manipulation of the insulating guide sheath  104  and electrode  102 . The groove  806  can be on the outside of the speculum  800  or can be inside the speculum  800 . The groove  806  can be open along its length so that the speculum  800  can be separated from the insulating guide sheath  104  once the speculum  800  is removed from the ear (e.g., after successful positioning of the insulating guide sheath  104 ). The groove  806  can also be closed along its length to hold the insulating guide sheath  104  in place during placement of the insulating guide sheath  104  in the ear. Where the groove  806  is closed, it can include a latch or other mechanism for opening the groove  806  to release the insulating guide sheath  104 . 
     The distal end  804  of the speculum  800  is placed into the ear facing into the tympanic membrane  136  for direct visualization inside the ear canal  122 . The proximal end  802  of the speculum  800  faces toward an operator and may be connected to an otoscope which will allow the visualization. Light  810  can be shone through the opening in the speculum  800  and into the ear canal  122  to view the inside of the ear. The opening of the proximal end  802  of the speculum  800  is significantly larger than the opening of the distal end  804  of the speculum  800 , and the proximal end  802  can be attached to an ordinary otoscope from which light is projected through the hollow lumen of the speculum  800 . During placement of the apparatus  100  in its primary or secondary positions, the distal end  804  of the speculum  800  can be inserted into the ear canal  122  of the subject, allowing direct visualization of the ear canal  122  and tympanic membrane  136 . The insulating guide sheath  104  and electrode  102  can then be advanced down the length of the groove  806  in the speculum  800  and manipulated into proper position. 
       FIG. 9  illustrates a side view of apparatus  900  with the stimulus generator  106  resting against the external ear  114 , according to an embodiment of the invention. In this embodiment, the stimulus generator  106  is an outer covering, plug, or other design that sits outside the ear canal  122 . In some embodiments, the stimulus generator  106  is shaped as a ring or a hook that sits upon the pinna, concha, scapha, tragus, or antitragus of the external ear (not shown). 
     In  FIG. 9 , the stimulus generator  106  is comprised of a wireless transmitter  908  and a wireless receiver  906 . The electrode  102  and the insulating guide sheath  104  are connected to the wireless receiver  906 , and the wireless receiver  906  sits against the external ear  114  in a manner that places the electrode  102  and insulating guide sheath  104  inside the ear canal  122 , bringing the distal tip  132  of the electrode  102  into proximity to the tympanic membrane  136 . Proximity to the tympanic membrane  136  is defined in relation to either the internal face of the tympanic membrane (observed from the position in the middle ear  116 ) or the external face of the tympanic membrane (observed from the position of the ear canal  122 ). 
     As shown in  FIG. 9 , the distal tip  132  of the electrode  102  is placed through an incision  302  in the tympanic membrane  136  within the middle ear  132 , achieving the secondary position. In other embodiments, the distal tip  132  of the electrode  102  is placed near the external face of the tympanic membrane  136  within the ear canal  122 , achieving the primary position (not shown). The wireless receiver  906  is held in place on the external ear  114  by an ear piece  902  that rests against the head, in this embodiment behind the external ear  114 . A variety of other ear piece designs can be used for holding the wireless receiver  906  in place as well. In this embodiment, the ear piece  902  is designed in  FIG. 9  to wrap around the back side of the ear and under the ear lobe. The apparatus  900  further includes a wireless transmitter  908  that can be separate and unattached from the body of the subject, or that can be attached to the body somewhere on the body or in clothing on the body (e.g., in a pocket, attached to a belt, worn around the neck, etc.). The wireless transmitter  908  is directly or indirectly in communication with a power source  108  that provides power to the wireless transmitter  908 . In some embodiments, one or more wires electrically couple the power source  108  to the wireless transmitter  908 . 
     The wireless transmitter  908  can communicate with the wireless receiver  906  on the distal ear piece  904  to generate stimulus energy for the electrode  102 . The wireless receiver  906  and the wireless transmitter  908  can be electromagnetically or inductively coupled. 
     The apparatus  900  of  FIG. 9  can be a chronic treatment device or can be an acute treatment device. For acute treatment of a stroke, the apparatus  900  can be placed on the subject&#39;s ear, and can deliver stimulus energy as desired by a physician or other operator. The stimulus generator  106  can be attached to a stimulus controller  140  that allows a physician or other operator to control when the energy is delivered, the intensity of the energy, etc. For chronic treatment of a stroke, the apparatus  900  can be worn as a chronic treatment device that is worn regularly by the subject. It can be worn all the time, at certain times of day, or whenever prescribed. The apparatus  900  can thus chronically stimulate and modulate one or more components of the facial nerve system in the vicinity of the ear. In another embodiment, one or more components of the chronic treatment apparatus are shaped to fit into an ear canal of the subject or against the external ear (e.g., as shown in  FIG. 9  or another design to be worn externally by the subject). In this embodiment, the components are on an external side of the tympanic membrane for chronically stimulating and modulating one or more components of the facial nerve system in the vicinity of the ear. 
       FIG. 10  illustrates a side view of apparatus  1000  with the stimulus generator  106  resting against the external ear  114 , according to an embodiment of the invention. The design is similar to that of  FIG. 9 , but in this case the power source  108  directly connects to the distal ear piece  904 . There is no wireless transmitter or receiver in this embodiment, therefore the stimulus generator  106  is represented as a single object that received power from the power source  108  through the ear piece  902 . The distal tip  132  of the electrode  102  can be placed in proximity to the tympanic membrane  136 , achieving either the primary or secondary position as needed. 
       FIG. 11 a    illustrates a side view of apparatus  1100  with an electromagnetic coil  1102  resting against the external ear  114 , according to an embodiment of the invention. The coil  1102  has a central opening  1106  through which light  810  and sound can be transmitted. The electromagnetic coil  1102  is worn against the external ear using an ear piece. This ear piece can be similar to ear piece  902  (including connecting directly to the stimulus generator  106  which connects directly to the power source  108 ), as is shown in  FIG. 10 , or can be designed in a different manner as desired. In some embodiments, the apparatus can include the wireless transmitter/receiver design of  FIG. 9 , in which the ear piece  902  does not connect directly to the power source  108 , but is worn as apparatus  900  is worn. The electromagnetic coil  1102  acts as the stimulus generator in this embodiment, and provides the stimulus energy by producing an electromagnetic field  202  through which one or more components of the facial nerve system are stimulated. 
     In some embodiments, the electromagnetic coil  1102  is shaped largely as a circle or ring, as shown in  FIG. 11 a   . In other embodiments, the electromagnetic coil  1102  is shaped as a figure-8, a cloverleaf, or other configuration. A detachable connection between the distal ear piece  902  and the stimulus generator  106  allows for attachment of various configurations of the electromagnetic coil  1102 . In some embodiments, the electromagnetic coil  1102  is between 2 cm and 8 cm in diameter. 
     In some embodiments, there is a guide piece  1108  attached to the electromagnetic coil  1102 , where the guide piece is inserted into the ear canal  122  when the electromagnetic coil is placed against the external ear  114 . For example, the insertable guide piece  1108  can be a sound-dampening ear plug or a speculum for visualization of the tympanic membrane  136 . In some embodiments, the guide piece  1108  is positioned on the electromagnetic coil  1102  in a manner that orients the generated electromagnetic field  202  in a certain direction. In some embodiments, the guide piece  1108  is composed of ferromagnetic material that distorts or modifies the electric or magnetic field generated by the electromagnetic coil  1102  in a desirable manner. In some embodiments, the guide piece  1108  includes one or more fiducial markers that indicate the expected direction or position of the electromagnetic field  202  on an imaging study. 
     As shown in  FIG. 11 b   , some embodiments of the apparatus  1150  involve offsetting the electromagnetic coil  1152  from a position immediately over the ear canal in a manner determined by its attachment to the ear piece  902 .  FIG. 11 b    shows an electromagnetic coil  1152  shaped largely like an elongated pentagon in which attachment to the ear piece  902  at a position behind the external ear  114  places the electromagnetic coil  1152  over or near to the mastoid region  1170 , above the temporal bone. As in  FIG. 11 a   , the electromagnetic coil  1152  in this embodiment acts as the stimulus generator, and provides the stimulus energy by producing an electromagnetic field through which one or more components of the facial nerve system are stimulated. In some embodiments, the electromagnetic coil  1152  is connected through the ear piece  902  to the stimulus generator  106  which connects directly to the power source  108 . 
       FIG. 12 a    illustrates a side view of apparatus  1200  with an electromagnetic coil  1202  resting partially or completely inside the ear canal  122 , according to an embodiment of the invention. The coil  1202  has a central opening  1106  through which light  810  and sound can be transmitted. This design is similar to  FIG. 11 a    except that the coil  1202  forms a column that rests in, is wedged in, or is surgically attached to or implanted into the ear canal  122 . The electromagnetic coil  1202  can further connect directly to the stimulus generator  106  which connects directly to the power source  108 . In some embodiments, the apparatus  1200  can include the wireless transmitter/receiver design of  FIG. 9 . As with  FIG. 11 a   , the electromagnetic coil  1202  of  FIG. 12 a    acts as the stimulus generator and electrode in this embodiment, and provides the stimulus energy by producing an electromagnetic field  202  that stimulates one or more components of the facial nerve system. 
       FIG. 12 b    illustrates a side view of apparatus  1250  in which an electromagnetic coil  1202  is placed in the ear canal  122  without use of a supporting ear piece, inflatable cuff, or other similar positioning assistance, but rather is kept in position by its form-fitting shape. In some embodiments, a ferromagnetic bar  1252  is placed within the central opening  1106  of the electromagnetic coil  1202  such that magnetic energy is conducted through the ferromagnetic bar  1252  to its distal end  1254 . As illustrated in  FIG. 12 c   , placement of the distal end  1254  of the ferromagnetic bar  1252  near the facial nerve  124  as the nerve courses behind the middle ear  116  space allows for generation of a magnetic field  1256  surrounding the distal end  1254  that then stimulates the facial nerve  124 . This placement involves advancing the distal end  1254  of the ferromagnetic bar  1252  into the middle ear  116  through an incision  302  in the tympanic membrane  136 . In some embodiments, the ferromagnetic bar  1252  has a 180-degree bend within the electromagnetic coil  1202  so that the proximal and distal ends of the ferromagnetic bar  1252  are brought into proximity in an elongated “horseshoe” structure (not shown). In some embodiments, the ferromagnetic bar is composed of Permalloy or Mu-metal. In some embodiments, the magnetic field carried by the ferromagnetic bar is focused or amplified by placement of ferromagnetic material in the facial nerve canal, fallopian aqueduct, or middle ear space. 
     Atherosclerotic disease of the cerebral arteries narrows cerebral arteries, which may chronically impair blood flow to parts of the brain, thereby causing among other symptoms recurring near-strokes/transient ischemic attacks as blood flow becomes intermittently compromised. In order to overcome the narrowing in the cerebral arteries caused by atherosclerosis or other malformations, chronic stimulation of the facial nerve system provided by a chronic treatment device can be used to maintain dilation of the arteries, thereby preventing stroke caused by atherosclerotic disease. 
       FIG. 13  illustrates a side view of apparatus  1300  with the electrode  102  chronically positioned within the bone of the skull and/or soft tissues of the head for stimulation of one or more components of the facial nerve system, according to an embodiment of the invention. In some embodiments, the electrode  102  is positioned in proximity to a branch  126  of the facial nerve  124  that passes through the middle ear space  116 . Stimulation can then be achieved by application of electrical current from a stimulus generator  106 . In some embodiments, the stimulus generator  106  and power source  108  are implanted within the body, thereby allowing direct connection between the electrode  102  and the stimulus generator  106 . Also implanted in the body is a power source  108  that is connected directly to the stimulus generator  106  by one or more wires or other connectors. In some embodiments, a stimulus controller  140  controls one or more parameters of the stimulus energy applied to the electrode  102  by the stimulus generator  906  using a wireless transmitter  908  external to the body that transmits information to a wireless receiver  906  connected to the stimulus generator  106  where the wireless receiver  906  is implanted within the body. 
       FIG. 14  illustrates a side view of apparatus  1400  with the electrode  102  positioned within the middle ear  116  by means of the Eustachian tube  120  for stimulation of one or more components of the facial nerve system, according to an embodiment of the invention. In some embodiments, the electrode  102  is in direct connection with a stimulus generator  106  placed within the middle ear  116  or the Eustachian tube  120 . Stimulus energy from a power source  108  with parameters determined by a stimulus controller  140  can be provided to the stimulus generator  106  either by direct connection between the stimulus controller  140  and the stimulus generator  106  through the Eustachian tube (not shown) or wirelessly by transmission of the stimulus energy from a wireless transmitter  908  placed external to the body to a wireless receiver  906  that is in direct connection with the stimulus generator  906 . In other embodiments, a wireless transmitter  908  is an aural appliance (not shown) configured to fit against the external ear  114 . Circuitry in the wireless transmitter  908  can drive the wireless transmitter  908  to transmit stimulus energy to the wireless receiver  906 . Similarly, circuitry in the wireless receiver  906  can receive the stimulus energy and transmit the energy to the stimulus generator  106 . The apparatus  1400  positioned in the middle ear  116  in this manner and supplied with stimulus energy by wireless transmission can be used for acute or chronic treatment of a disorder of abnormal blood flow within the head. Electrical stimulation  402  of a branch  126  of the facial nerve can be performed, as in this example, or other means of stimulation can be employed. In other embodiments, direct connection of the stimulus generator  106  and the stimulus controller  140  can be maintained by one or more wires running through the Eustachian tube  120  and exiting the head via nasal or oral passages. 
     Neural Structure Modulation Methods 
     Referring now to  FIG. 15 , there is shown a flow diagram providing a method for neural structure modulation, according to an embodiment of the invention. It should be understood that these steps are illustrative only. Different methods of the invention may perform the illustrated steps in different orders, omit certain steps, and/or perform additional steps not shown in  FIG. 15  (the same is true for the other Figures). The method can start and end at various points in the process, and often the method is a continuous process with multiple steps occurring simultaneously, so the Figures provide only an example of one ordering of method steps. In addition, the method can be performed using any of the apparatuses described herein or another apparatus capable of performing the steps provided below. 
     As shown in  FIG. 15 , the method includes a step of providing stimulation  1502  in the ear canal (primary position). For example, the stimulation can include providing stimulus energy to an electrode positioned in the ear canal, in the primary position for the apparatus. This may result in sufficiently improving  1504  blood flow to the brain, thus rendering the treatment of the stroke a success. However, stimulation in the primary position may not be successful for one of two reasons. First, stimulation  1508  in the primary position may not sufficiently improve blood flow to the brain, thus rendering the treatment of the stroke a failure. Second, even if blood flow to the brain is sufficiently improved by stimulation in the primary position, side effects associated with stimulation in the primary position may prevent the use of stimulation in the primary position  1506 . In case of failure of stimulation in the primary position, the method can further include a step of advancing an electrode into the middle ear by puncturing the tympanic membrane and inserting the electrode through the punctured tympanic membrane. The method can also include providing stimulation  1510  from this position in the middle ear, which is the secondary position for the apparatus. In this secondary position, the electrode is closer to some components of the facial nerve system for providing stimulation to improve blood flow, and certain components of the facial nerve system can be directly stimulated with electrical current. The stimulation  1510  provided from the secondary position may result in sufficiently improving  1504  blood flow, thus rendering the treatment of the stroke a success. Thus, in the embodiment of  FIG. 15 , the method includes first trying to stimulate the facial nerve system from the primary position (in the ear canal), and if this position does not provide the desired results, the method includes then trying to stimulate the facial nerve system from the secondary position (in the middle ear). However, the user does not have to perform the steps in this order, or may perform only one of the steps. For example, only the secondary position may be used if this is preferred. 
     Referring now to  FIG. 16 , there is shown a method of facial nerve system stimulation, according to an embodiment of the invention. If the means for first approaching the stimulation site will be via the Eustachian tube of the ear (e.g., due to poor access through the ear canal), the method includes moving  1602  the insulating guide sheath within a Eustachian tube of the ear to an internal side of the tympanic membrane. This method then continues to a step that includes moving  1613  the electrode within the insulating guide sheath (note that the moving  1602  of the insulating guide sheath and moving  1613  of the electrode can occur simultaneously). If the mechanism for approaching the stimulation site will not be via the Eustachian tube (e.g., will be via the ear canal), then the method follows a different course in the flowchart. If a speculum is to be used, the speculum is inserted  1606  into the ear canal, and the insulating guide sheath is inserted  1608  into the speculum. For example, the insulating guide sheath can be inserted  1608  through a groove or peripheral channel along the lateral length of a specialized otoscope speculum and then into the ear canal of the subject under direct visualization of anatomical structures within the ear. If no speculum is to be used, the insulating guide sheath is moved  1610  into the ear canal without a speculum. The moving  1610  of the insulating guide sheath into the ear can include moving the insulating guide sheath into the ear canal and into proximity of the tympanic membrane. 
     Once the device has been moved  1610  into the ear canal, the user can opt to proceed with stimulation from the ear canal (primary position), or can opt to advance the device into the middle ear to perform the stimulation in the middle ear (secondary position). If the stimulation is to occur in the middle ear, the moving  1610  of the insulating guide sheath into the ear can lead to steps of puncturing  1604  the tympanic membrane with the insulating guide sheath (e.g., a sharpened distal tip of the insulating guide sheath) or other surgical procedure and moving  1605  the insulating guide sheath into the middle ear. In some embodiments, the user might opt to first provide stimulation from the ear canal, and if the appropriate response does not occur, the user can then opt to move the device into the middle ear for providing stimulation in the middle ear. 
     With successful placement of the distal end of the insulating guide sheath in the middle ear or with placement of the distal end of the insulating guide sheath in the ear canal external to the tympanic membrane, the method further includes moving  1612  the distal tip of the electrode within the insulating guide sheath to the end of the insulating guide sheath (for stimulation in the primary position) or moving  1613  the distal tip of the electrode out of the distal end of the insulating guide sheath (for stimulation in the secondary position). This can also occur simultaneously with the any of the steps described above or it may precede any of the steps in certain methods. In the primary position, the distal tip of the electrode can remain inside the insulating guide sheath in a position near the external side of the tympanic membrane and in the secondary position, the distal tip can be exposed near an internal side of the tympanic membrane. The method also includes stabilizing  1615  the insulating guide sheath to hold the insulating guide sheath in place within the ear while the distal tip of the insulating guide sheath is located in the middle ear, or stabilizing  1616  the insulating guide sheath to hold the insulating guide sheath in place within the ear while the distal tip of the insulating guide sheath is located in the ear canal. Stabilizing  1615 , 1616  can include inflating an inflatable cuff associated with the outer wall of the insulating guide sheath to fit the insulating guide sheath against a surface of the ear or to hold the insulating guide sheath in place within the ear canal. Stabilizing  1615 , 1616  can further include stabilization with an ear piece fixed to the external ear. 
     Referring now to  FIG. 17 , there is shown a continuation of the flow chart of  FIG. 16 , according to an embodiment of the invention. If a material, gel, or solution (e.g., electrically-conductive gel or solution to increase conductivity, an anesthetic or other pharmacological agent to eliminate an unwanted response of tissue local to the electrode, etc.) is to be injected into the insulating guide sheath, the method includes injecting  1702  such material, gel, or solution through an injection port out the distal tip of the insulating guide sheath to facilitate treatment of the subject. This can also occur earlier or later in the process, or at multiple times in the process with the same or different materials, gels, or solutions, as desired. The material, gel, or solution can be released from the distal end of the insulating guide sheath into an ear canal, middle ear, or Eustachian tube. 
     The method also includes providing  1704  power via a power source for supplying the stimulus energy to the electrode (the power may also be provided  1704  automatically, as the device may be constantly connected to or in communication with the power source). The power can be provided  1704  via wires connecting the power source to the device, or wirelessly via a wireless transmitter/receiver. In addition, the method includes supplying  1706  stimulus energy to the electrode to stimulate one or more components of the facial nerve system in the vicinity of the ear (e.g., a facial nerve, a tympanic plexus, a geniculate ganglion, a tympanic plexus, a sphenopalatine nerve or ganglion, a petrosal nerve, etc.). In some methods, supplying  1706  stimulus energy to the electrode modulates blood flow to the brain of the subject or enhances delivery of a blood-borne pharmacologic agent to treat stroke or another condition of the subject. The stimulus energy can be supplied via a wire connecting a stimulus generator to the electrode or wirelessly via a stimulus generator that is not in direct contact with the electrode. Where the electrode is in the primary position (in the ear canal), supplying  1706  stimulus energy can create an electromagnetic, electric, or magnetic field to stimulate the facial nerve system from the external side of the tympanic membrane. Where the electrode is in the secondary position (in the middle ear), an electrical current can be directly supplied to components of the facial nerve system within the middle ear and may also be provided to certain components of the facial nerve system indirectly (e.g., via an electromagnetic field). In some methods, supplying  1706  stimulus energy drives electrical current between a cathodic site and an anodal site of a bipolar electrode. In some embodiments, supplying  1706  stimulus energy drives electrical current from a monopolar electrode to a ground wire applied to the pinna of the ipsilateral or contralateral ear, or to another part of the head. 
     If any adjustments are needed or desired regarding the stimulus energy, the method can include adjusting  1708  the stimulus energy. For example, the adjustments can be made based on physiological or pathophysiological responses of the subject to the stimulus energy. The method can continue with supplying  1706  and adjusting  1708  as needed until the method is done. When the method is done (i.e., the treatment is successful and complete), the insulating guide sheath and/or electrode can be removed  1718  from the ear. If the device has a detachable electrode tip, the method can include detaching  1720  the tip and attaching  1722  a new tip. 
     If the method is not finished because successful treatment was not achieved and because appropriate stimulation in both the primary and secondary positions was not attempted, the method can continue to completion with steps  1602 ,  1604 ,  1605 ,  1606 ,  1608 ,  1610 ,  1613 ,  1615 ,  1702 ,  1704 ,  1706 ,  1708 ,  1718 ,  1720 , and/or  1722 , described above. For example, if the device was initially used in the primary position in the ear canal, but the secondary position was not attempted, the device can then be moved into the secondary position in the middle ear if stimulation in the middle ear is judged appropriate. 
     Referring now to  FIG. 18 , there is shown a method of chronic nerve stimulation, according to an embodiment of the invention. If the method is to occur in the middle ear, the method includes surgically, interventionally, or endoscopically implanting  1802  the chronic treatment device (e.g., an electrode with or without an insulating sheath) within or in proximity to the ear of the subject. This may include placement of the chronic treatment device in the middle ear space, in the Eustachian tube, into a bone of the skull, or into a soft tissue or potential space of the head. If the method is not to involve implanting  1802  the chronic treatment device, and instead will occur in the ear canal, the external ear, or on the surface of the head, the method includes placing  1804  the chronic treatment device into the ear canal, on the external ear, or on the surface of the head (e.g., the mastoid region behind the external ear) of the subject. Certain positions may only allow for stimulation of one or more components of the limited facial nerve system. In some methods, the device can be implanted into the facial nerve canal, the Eustachian tube, the internal auditory meatus, the Fallopian aqueduct, the mastoid antrum, the temporal bone, the cartilage of the ear, or the epitympanic recess of the subject. The method also includes supplying  1806  stimulation (e.g., via a stimulus generator that can be in wireless communication with the electrode) to the electrode over a period of time to chronically stimulate one or more components of the facial nerve system in the vicinity of the ear. In some methods, the supplying  1806  of stimulation step includes supplying stimulation automatically over a period of time to maintain relaxation of one or more cerebral or carotid arteries associated with the facial nerve system for treatment or prevention of a stroke, particularly stroke caused by atherosclerotic disease. The method can further include providing  1808  power via a power source for supplying the stimulus energy to the electrode. 
     The method can also include monitoring  1810  one or more physiological or pathophysiological responses of the subject over a period of time. In this method, if it is determined that an adjustment is needed, the method can include adjusting  1812  the intensity, frequency, etc. of the stimulus energy supplied to the electrode. The adjustment  1812  can be made based on the one or more physiological or pathophysiological responses of the subject, or based on other factors. In some methods, the adjustment  1812  can also occur automatically without requiring any action by a physician or subject to make the adjustment. In other embodiments, the physician or subject can have access to the monitored  1810  responses of the subject, and can control the adjustment  1812  based on the monitoring  1810 . The method can include continued supplying  1814  of stimulus energy to the electrode with periodic monitoring  1810  and adjusting  1812  as needed over a period of time to chronically treat the subject. In this manner, if stimulation is needed or desired of one or more components of the facial nerve system to dilate vessels and prevent stroke, the chronic device can provide such stimulation. This can be done automatically or under the control of a physician or of the subject using the device. 
     Various of the features described herein for the different apparatus designs can be used with other apparatus designs as well. In addition, the numerical values presented herein are approximate, and can include numbers below or above the stated values. Furthermore, the numerical ranges presented herein can include any of the values, fractional values, or ranges falling within the numerical range. While the present teachings are described in conjunction with various embodiments and methods, it is not intended that the present teachings be limited to such embodiments. On the contrary, the present teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those of skill in the art. Most of the words used in this specification have the meaning that would be attributed to those words by one skilled in the art. Words specifically defined in the specification have the meaning provided in the context of the present teachings as a whole, and as are typically understood by those skilled in the art. In the event that a conflict arises between an art-understood definition of a word or phrase and a definition of the word or phrase as specifically taught in this specification, the specification shall control. It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. In addition, number labels included in the drawings are organized to provide clarity. In some cases, the same number label is used throughout to refer to a structure that corresponds with another structure in a different apparatus design of a different figure, even though that structure may be somewhat differently designed or have some different components, a different size or shape, etc. For example, insulating guide sheath  104 , electrode  102 , and distal tip  132  are given the same number labels throughout. In some cases, a different number label is used to delineate corresponding structures across different apparatus designs, even though that structure may be generally designed the same or have the same components, size or shape, etc.