JP2010510862A - Uniform electric field induction method - Google Patents

Abstract

The present invention provides a method and apparatus for delivering an electric field to the body, delivering a polarized magnetic field to the body in a first direction toward the desired target in the body, and the electric field across the desired target. Changing the direction of delivery of the magnetic field to a second direction toward the desired target.

Description

  The present invention relates generally to the use of a magnetic field, and more particularly to a method of using a magnetic field to induce an electric field uniformly for therapeutic purposes.

  Exposure to electromagnetic fields (EMF) has become an increasingly useful tool in the treatment of many medical conditions. For example, exposure to a time-varying magnetic field is an approved method for accelerating bone and wound healing. For example, EMF can be used to reduce damage to the heart during a heart attack and to protect the bone marrow during chemotherapy and x-ray therapy for tumor destruction.

  When EMF is applied to a cell, the electric field that acts on the cell is the primary mechanism for EMF to act on the cell. As the main objective, the use of a low frequency, time-varying magnetic field is the simplest and controllable way to generate an electric field across the tissue to be treated. A time-varying magnetic field can be formed outside the body (eg, with one coil pair and a time-varying current source). When this field enters the body, it induces a time-varying electric field (by Faraday's law). Since the magnetic properties of the body are very uniform, it is very easy to form a uniform magnetic field in the body. However, the induced electric field is very non-uniform because the electrical conductivity of the body can vary greatly from organ to organ (eg, lung to heart) and within an organ (eg, myocardium to heart blood).

  This lack of uniformity implies a serious limitation of the therapeutic application of time-varying magnetic fields. A good example of this limitation is the use of a magnetic field to reduce damage to the heart after an ischemic event (eg, a heart attack). Application of a magnetic field for more than 30 minutes induces heat shock protein (hsp) activation in myocardial cells. These hsp function to protect the heart from cell death (necrosis) during cellular stress caused by disruption of blood flow (ischemia). The problem that exists with this technique is that the induced electric field is so different that in many areas of the heart, the magnitude of the induced electric field is not sufficient for the cells to produce hsp. For example, the lung is a high resistance region adjacent to the heart. As a result, when an induced electric field passes through both the lung and the heart, most of the magnetic field appears across the lung and only a few appear in the heart. Even if an induced electric field is applied in a direction that does not cross the lungs, the blood has a very low conductivity compared to the myocardium, so there are areas in the heart that do not receive a large electric field.

  Which region of the organ does not receive a large electric field is highly dependent on the direction of the applied magnetic field and thus the direction of the induced EMF. One proposed solution may simply be to apply the field simultaneously in the x, y and z directions. However, this does not work because the sum of these field vectors is simply a new magnetic field in one direction.

  It is an object of the present invention to provide a uniform electric field induction method and apparatus.

  According to a first broad aspect of the invention, there is provided a method of delivering an electric field to the body, the method delivering a polarized magnetic field to the body in a first direction toward a desired target in the body. And changing the direction of delivery of the magnetic field to a second direction toward the desired target so as to induce an electric field across the desired target.

  According to a second broad aspect of the invention, a method for delivering an electric field to a body is provided, the method directing a first magnetic field from a first coil to the body to a desired target in the body. Delivering in a first orientation; and delivering a second magnetic field from a second coil in a second orientation directed to the desired target in the body to induce an electric field across the desired target. Only one magnetic field is delivered to the body at any given time.

  According to a third broad aspect of the invention, a method for delivering an electric field to a body is provided, the method directing a first magnetic field from a first coil to the body and to a desired target in the body. Delivering in a first orientation; delivering a second magnetic field from a second coil in a second orientation directed to a desired target in the body; and to induce an electric field across the desired target And delivering a third magnetic field from a third coil in a third orientation toward the desired target in the body.

  According to a fourth broad aspect of the present invention, there is provided an apparatus for delivering an electric field to a body, the apparatus applying a first magnetic field from a first coil to the body and a desired target in the body. Means for delivering in a first orientation towards the second; a second magnetic field in a second orientation towards the desired target in the body from a second coil so as to induce an electric field across the desired target Means for delivering; and means for alternating current flow between the first coil and the second coil.

2 is a schematic diagram of a coil arrangement according to one embodiment of the present invention in which two coil pairs are oriented at right angles to one another. FIG. 2 is a schematic diagram of a coil arrangement according to one embodiment of the present invention in which two coil pairs are oriented at right angles to one another. FIG. FIG. 3 is a schematic diagram of a coil arrangement according to one embodiment of the present invention using three coil pairs. FIG. 5 is a graph of on / off interval and percentage of maximum response for different models of EMF inducing effects, including hypoxic protection (circles) and changes in enzyme activity (squares). FIG. 5 is a table showing the effect of EMF on post-stroke attacks using vertical and horizontal linear EMF exposure polarization. FIG. 6 is a table showing the effect of EMF on post-stroke attacks using vertical, horizontal, and alternating vertical and horizontal linear EMF exposure polarization.

  The present invention will be described with reference to the accompanying drawings.

(Detailed explanation)
Before describing the invention, it is convenient to define several terms. It will be understood that the following definitions are used throughout this specification.

(Definition)
Where the definition of a term departs from the commonly used meaning of the term, the applicant intends to utilize the definitions provided below unless otherwise indicated.

  For the purposes of the present invention, the term “linearly polarized magnetic field” refers to a magnetic field that changes in time but is always directed along a predetermined fixed line.

  For the purposes of the present invention, the term “circularly polarized magnetic field” refers to a magnetic field that appears as a field vector rotates around a fixed axis and turns into a circle.

  For the purposes of the present invention, the term “linear vertical field” refers to a linearly polarized field in which the field vectors are oriented vertically.

  For the purposes of the present invention, the term “linear horizontal field” refers to a linearly polarized field in which the field vectors are oriented horizontally.

  For the purposes of the present invention, the term “circular vertical field” refers to a circularly polarized field in which the field vector rotates about its vertical axis.

  For the purposes of the present invention, the term “circular horizontal field” refers to a circularly polarized field in which the field vector rotates about its horizontal axis.

  For the purposes of the present invention, the term “uniform electric field” refers to an induced electric field that is essentially unchanged in all tissues to be treated.

  For the purposes of the present invention, the term “orientation” refers to the arrangement, configuration, orientation, etc. of a specified element, such as the orientation of a magnetic field.

(Explanation)
The present invention provides a method and apparatus for delivering an electric field to the body, which delivers a first magnetic field from a first coil to the body in a first orientation that directs the body to a desired target. And delivering a second magnetic field from the second coil in a second orientation directed to the desired target in the body and inducing an electric field across the desired target, always with only one magnetic field Are delivered to the body. The present invention provides increased uniformity of the induced electric field. Increased uniformity is useful. Because if the induced electric field is not uniform, its value can be below the threshold necessary to induce a useful biological effect (in some areas of the tissue being treated), so that the treatment is partially It is only effective.

  Under certain conditions, the effectiveness of magnetic field therapy (its duration can be, for example, about 30 minutes to about 60 minutes) is significantly enhanced when the direction of the magnetic field direction changes over time during treatment. obtain.

  As the linearly polarized magnetic field, one that reciprocates from one direction (for example, vertical) to the direction perpendicular thereto (for example, horizontal) and alternately switches can be used. In other embodiments of the invention, the field delivery direction may be switched about 90 degrees +/- 30 degrees relative to the original direction of the field.

  In some embodiments of the invention, the timing of exposure is an important component of effective treatment. In some embodiments of the invention, the magnetic field is held in any constant direction for at least 5 seconds before switching the delivery direction to the new direction. By changing the delivery direction of the magnetic field, an electric field can be induced across the desired target. In some embodiments of the invention, the minimum exposure time in any direction before switching the delivery direction is greater than 10 seconds. In some embodiments of the invention, the maximum exposure time in any direction before switching the delivery direction is 300 seconds or more. Thus, a suitable duration of exposure in any one direction can be from about 5 seconds to about 300 seconds or more, preferably from about 10 seconds to about 30 seconds. The time frame of exposure can be modified depending on the tissue or cell being treated, the frequency of exposure, and the length of time between treatments.

  A magnetic field for use in the present invention may be generated, for example, by two coil pairs. The two coil pairs are oriented at right angles to each other, with AC current flowing alternately in one pair and then in that right pair. Such an arrangement provides a field in two perpendicular directions (ie, the planar orientation of one magnetic field is substantially perpendicular to the planar orientation of the other magnetic field). 1 and 2 provide a schematic illustration of a coil arrangement according to an embodiment of the present invention in which two coil pairs are oriented at right angles to each other.

  One goal of the present invention is to obtain a uniform induction electric field. Therefore, according to one embodiment of the present invention, it is preferable to start with a reasonably uniform magnetic field. Although current flowing through a single coil can be used in the present invention, such an arrangement creates a relatively non-uniform magnetic field and consequently introduces some of the problems described above. Coil pairs located in planes that are perpendicular to each other produce a much more uniform magnetic field when current flows through them so that the fields of those two coils are summed in the region between the coils.

  In another arrangement of the present invention, two coil pairs are arranged at right angles to each other, and one pair of AC currents is 90 degrees out of phase with the other coil pair to form a circularly polarized magnetic field. According to embodiments of the present invention, the current may be a phase shift other than 90 degrees (eg, 90 degrees +/− 30 degrees). If the current is out of phase but not 90 degrees out of phase, the resulting field is a circularly polarized field (caused by the 90 degree out of phase current element) and a linearly polarized magnetic field (currents that are in phase with each other). Can be considered to be composed of This is generally not as effective as the 90 degree phase shift condition. However, such an arrangement is within the scope of the present invention. Therefore, for example, a magnetic field that continuously rotates from the vertical direction to the horizontal direction is formed. Such an arrangement provides a field in two perpendicular directions.

  Another embodiment of the invention provides a circularly polarized magnetic field, the circular field having a plane with a direction that is switched in time to its perpendicular direction. This can be achieved by three coil pairs oriented perpendicular to each other. Such an arrangement can be seen in FIG. These coils may be referred to as coil pair 302, coil pair 304, and coil pair 306, respectively. In an exemplary embodiment of the invention, first an AC current flows through coil pairs 302 and 304. The currents in these coils can be 90 degrees out of phase. After a period of time (eg, at least about 5 seconds, preferably longer than about 10 seconds, but usually not more than about 300 seconds), with and without 90 degrees out of phase current, coil pair 302 and The current is switched so that the coil pair 306 is excited. In one embodiment of the invention, coil pair 304 and coil pair 306 are also 90 degrees out of phase. Such an arrangement provides a field in three perpendicular directions.

  The magnetic field used in embodiments of the present invention includes a field that ranges in frequency from about 10 Hz to 5 GHz. The type of magnetic field used in a given implementation can be determined by equipment costs and ease of application. According to an embodiment of the present invention, the frequency of the applied magnetic field is at least about 20 Hz. In other embodiments of the invention, the frequency of the applied magnetic field can be from about 20 Hz to about 60 Hz, or more. The current in the coil must be large enough to create a magnetic field in the tissue to be treated that is sufficient to induce an electric field of greater than about 10 microvolts / meter at 60 Hz. For frequencies above 60 Hz, the magnetic field can still be the same as calculated above for the 60 Hz condition. At frequencies below 60 Hz, the magnetic field increases inversely with decreasing frequency. Thus, for example, at 20 Hz, the magnetic field is three times larger than required at 60 Hz.

  Any suitable magnetic field generating coil may be used for use in the present invention, including Helmholtz coils and the like. 1, 2 and 3 show schematic diagrams of coil arrangements, but should not be construed to limit the application of the present invention to such arrangements. The coils of the present invention can be of various shapes and arrangements now known or later developed.

  Embodiments of the present invention may use non-thermal EMF (ie, a field that does not cause an increase in tissue temperature). Non-thermal EMF forms a desired biological effect, such as modification of hsp concentration, when field parameters (eg, amplitude, frequency, and waveform) are unchanged for a period or interval of at least a few seconds. obtain. Applying non-thermal EMF to the tissue with an on-off cycle ranging from about 0.1 seconds to about 1-2 seconds has no biological effect. In one embodiment, non-thermal EMF having an on-off cycle longer than 10 seconds is applied to the tissue to produce the desired biological effect.

  The present invention may be used in a variety of treatment protocols, including a single treatment or multiple treatments over a day, a week, or weeks or months, depending on the particular application. A single treatment may be provided over a period of seconds, minutes or hours depending on the particular application.

  EMF exposure according to the present invention can be used to target and enhance treatment or palliative treatment. Treatment or palliative treatment includes, but is not limited to, physical, chemical, radioactive or gene therapy applied for the treatment and prevention of disease. The present invention improves the effectiveness of magnetic field therapy when treating various organs of the body against conditions including cancer, arthritis, psoriasis, diabetes, autoimmune diseases, heart attacks and the like.

  Application of EMF activates cellular signaling pathways that result in the production of stress proteins. These stress proteins protect cells from harmful stimuli. However, prolonged or repetitive stimulation causes the cells to reduce or down-regulate this stress response. This leaves the cells highly sensitive after EMF exposure. Thus, any therapeutic agent applied to damage these cells will be more effective. Thus, the present invention can be used in a combined manner that correlates the use of EMF and temporary invariant requirements with the ability to concentrate the biological effects of EMF. Such methods have the ability to selectively protect or deprotect the tissue volume, depending on the parameters of the applied EMF exposure. Embodiments of the present invention can further target a specific volume of tissue to focus the effects of selected EMF exposure.

  For cancer, the present invention can also be used in combination with anticancer or chemotherapeutic agents, or in combination with radiation therapy. Application of long-term EMF exposure to tumor cells according to embodiments of the present invention may make tumor cells more sensitive to subsequent treatment with toxic chemicals such as taxol. In one embodiment, the cells are exposed to EMF prior to administration of taxol, which leads to a very significant increase in the toxic effects of taxol. For example, chicken embryos exposed to EMF for 48 hours before taxol injection and 48 hours after injection showed an increase in the toxic effects of taxol.

  It is described herein that embodiments can be applied to other medical procedures using harmful stimuli aimed at destroying or modifying selected volumes of tissue or biological cells for reasons other than cancer treatment. It will be clear to those skilled in the art who have read Some examples of this are benign tumors, keloids, arterio-venous malformations, benign prostatic hypertrophy, splenomegaly, and the like. Furthermore, the auxiliary application of the embodiments may not only be for treatment aimed at healing, but may also be a palliative aid, e.g. ionizing radiation used to reduce tumor mass or growth At the same time, it temporarily relieves the symptoms caused by the tumor mass.

  Furthermore, when a time-varying magnetic field is used as a preventive measure to protect against hypoxia, UV light, X-ray stress or other adverse stresses, the present invention provides a time-varying magnetic field. Make it more effective. However, the protection that is induced is highly dependent on the dose of EMF used. Short-term field exposure (ranging from 20 minutes to several hours) is protective against stress and can reduce cytokine expression leading to swelling and inflammation. Long-term pre-exposure (longer than 12 hours) can make cells, tissues and organs more susceptible to damage from subsequent stress. The degree of protection or increased sensitivity depends on the length of exposure time and the strength of the applied EMF.

  The following data shows the effect of the present invention. A study was conducted to investigate the ability of the induced electric field in the rat heart to protect against simulated heart attacks. In this study, the magnetic field was applied in only one of two directions (vertical or horizontal straight line relative to the rat). As can be seen in the data shown in Table 1 of FIG. 5, no statistically significant reduction was observed in necrotic heart tissue. This was because most of the myocardium was not exposed to an electric field that could induce biological effects (in this case ischemic protection).

  However, further studies have shown that myocardial tissue salvage was improved by a factor of 3 by varying the applied magnetic field in time so that more than one plane of magnetic field is used during exposure. It was issued. In this second study, rats were exposed to either a circularly polarized field (in a vertical or horizontal plane) or a field where the direction of the applied magnetic field switches from vertical to horizontal every 30 seconds. In these experiments, as shown in Table 2 of FIG. 6, a reduction of about 15% was observed in the necrotic tissue compared to the reduction of about 5% in Table 1 of FIG.

  As summarized in Table 1 of FIG. 5 and Table 2 of FIG. 6, all of the linear unidirectional EMF (vertical or horizontal) had a negligible effect on reducing the infarct area after a simulated heart attack. This is expected due to the non-uniform nature of the electric field induced by these unidirectional exposures. However, as summarized in Table 2 of FIG. 6, the other EMF exposures tested (vertical circles, horizontal circles or alternating) resulted in a significant improvement in heart damage reduction. These findings support the view that multi-directional EMF exposure can induce a more uniform electric field and, as a result, can have significant biological effects on tissues.

  According to one embodiment of the present invention, a multi-directional magnetic field exposure approach can be combined with a specific timing protocol to increase its effectiveness. A specific time scale of exposure induces a more robust biological effect. It has already been described that complete biological effects can be achieved if the magnetic field exposure is temporarily unchanged for some minimum period (eg longer than about 10 seconds). FIG. 4 illustrates this phenomenon for several different models of EMF inducing effects, including hypoxia protection (circles) and changes in enzyme activity (squares). As can be seen in FIG. 4, according to one embodiment of the present invention, the maximum induced biological effect is achieved with a minimum on / off time interval of about 10 seconds. Thus, in one embodiment of the invention, the field direction is not switched on a time scale shorter than about 10 seconds. However, in other embodiments, the time scale may be longer or shorter than 10 seconds between field direction switching.

  In addition, all uniaxial exposures form inhomogeneous induced electric fields in the tissue, whereas most multiaxial exposures do this as well. This is because when tissue is exposed to a multi-directional field simultaneously, the actual applied field is the sum of all the fields applied in their different directions, resulting in a unidirectional magnetic field exposure vector. To avoid this situation, multidirectional exposures can be applied other than simultaneously. One way to achieve this is to use a circularly polarized magnetic field whose direction changes continuously (eg, a vertical or horizontal circle shown in Table 2 above). However, this method produces an induced electric field that is relatively difficult to quantify because there may still be a region of sub-threshold induced electric field and is not always the most effective means to induce an electric field in tissue. Instead, according to one embodiment of the present invention, the direction / orientation changes at a constant time interval in the second exposure plane (as evidenced by the alternating linear data shown in Table 2). Use of a magnetic field (straight line or circle) is provided. If the magnetic field exposure is temporarily unchanged for some minimum period (eg, longer than about 10 seconds), a full biological effect can be achieved.

  While the invention has been fully described in conjunction with several embodiments thereof with reference to the accompanying drawings, it will be understood that various changes and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the present invention, as defined in the appended claims, without departing therefrom.

Claims (54)

A method of delivering an electric field to the body, the method comprising:
Delivering a polarized magnetic field to the body in a first direction toward a desired target in the body; and
Changing the direction of delivery of the magnetic field to a second direction toward the desired target so as to induce an electric field across the desired target;
Including a method.   The method of claim 1, wherein the planar orientation of the magnetic field in the first direction is perpendicular to the planar orientation of the magnetic field in the second direction.   The method of claim 1, wherein the magnetic field is delivered in the first direction for at least 5 seconds before the delivery direction is changed to the second direction.   The method of claim 1, wherein the magnetic field is delivered in the first direction for at least 10 seconds before the delivery direction is changed to the second direction.   The method of claim 1, wherein the magnetic field is delivered in the first direction for at least 30 seconds before the delivery direction is changed to the second direction.   The method of claim 1, wherein the magnetic field is delivered for 300 seconds or less in the first direction before the delivery direction is changed to the second direction.   The method of claim 1, wherein the magnetic field is delivered to the body from about 30 minutes to about 60 minutes.   The method of claim 1, wherein the target comprises cancer cells.   The method of claim 1, wherein the target comprises heart tissue.   The method of claim 1, wherein the magnetic field is linearly polarized light.   The method of claim 1, wherein the magnetic field is circularly polarized light.   The method of claim 1, wherein the magnetic field is formed by flowing an AC current through at least one coil pair.   The method of claim 1, wherein the magnetic field is formed of at least two coil pairs.   The method of claim 13, wherein the at least two coil pairs are arranged to deliver a magnetic field in at least two different directions.   The method of claim 14, wherein AC current flows alternately through the at least two coil pairs.   The method of claim 15, wherein the AC current of one coil pair is approximately 90 degrees out of phase with the AC current of at least one other coil pair.   The method of claim 15, wherein the AC current of one coil pair is about 60 degrees to about 120 degrees out of phase with the AC current of at least one other coil pair.   The method of claim 1, wherein the delivered magnetic field comprises a frequency of about 20 Hz or greater.   The method of claim 1, wherein the delivered magnetic field comprises a frequency from about 20 Hz to about 60 Hz. A method of delivering an electric field to the body, the method comprising:
Delivering a first magnetic field from a first coil to a body in a first orientation toward a desired target in the body; and
Delivering a second magnetic field from a second coil in a second orientation toward the desired target in the body to induce an electric field across the desired target, where only one magnetic field is always present Delivered to the body,
Method.   21. The method of claim 20, wherein at least one of the first magnetic field in a first orientation and the second magnetic field in a second orientation comprises a linearly polarized magnetic field.   21. The method of claim 20, wherein at least one of the first magnetic field in a first orientation and the second magnetic field in a second orientation comprises a circularly polarized magnetic field.   21. The method of claim 20, wherein at least one of the first coil and the second coil comprises a coil pair.   21. The method of claim 20, wherein the first orientation is perpendicular to the second orientation.   21. The method of claim 20, further comprising delivering a third magnetic field from a third coil in a third orientation.   26. The method of claim 25, wherein the first orientation, the second orientation and the third orientation are perpendicular to each other coil orientation.   21. The method of claim 20, wherein the first magnetic field is delivered in the first orientation for at least 5 seconds before the delivery orientation is changed to the second orientation of the second magnetic field.   21. The method of claim 20, wherein the first magnetic field is delivered in the first orientation for at least 10 seconds before the delivery orientation is changed to the second orientation of the second magnetic field.   21. The method of claim 20, wherein the first magnetic field is delivered in the first orientation for at least 30 seconds before the delivery orientation is changed to the second orientation of the second magnetic field.   21. The method of claim 20, wherein the first magnetic field is delivered in the first orientation for 300 seconds or less before the delivery orientation is changed to the second orientation of the second magnetic field.   21. The method of claim 20, wherein the magnetic field is delivered to the body for a total of about 30 minutes to about 60 minutes.   21. The method of claim 20, wherein the target comprises cancer cells.   21. The method of claim 20, wherein the target comprises heart tissue.   21. The method of claim 20, wherein AC current flows alternately through the first coil and the second coil.   35. The method of claim 34, wherein the AC current flowing through the first coil is approximately 90 degrees out of phase with the AC current flowing through the second coil.   35. The method of claim 34, wherein the AC current flowing through the first coil is about 60 degrees to about 120 degrees out of phase with the AC current flowing through the second coil. A method of delivering an electric field to the body, the method comprising:
Delivering a first magnetic field from a first coil to a body in a first orientation toward a desired target in the body;
Delivering a second magnetic field from a second coil in a second orientation toward the desired target in the body; and
Delivering a third magnetic field from a third coil in a third orientation directed toward the desired target in the body to induce an electric field across the desired target;
Including a method.   38. At least one of the first magnetic field in a first orientation, the second magnetic field in a second orientation, and the third magnetic field in a third orientation comprises a linearly polarized magnetic field. Method.   38. At least one of the first magnetic field in a first orientation, the second magnetic field in a second orientation, and the third magnetic field in a third orientation comprises a circularly polarized magnetic field. Method.   38. The method of claim 37, wherein at least one of the first coil, the second coil, and the third coil comprises a coil pair.   38. The method of claim 37, wherein the first orientation, the second orientation, and the third orientation are perpendicular to each other coil orientation.   38. The method of claim 37, wherein at least one of the first magnetic field, the second magnetic field, and the third magnetic field is delivered for at least 5 seconds before the delivery orientation is changed to a different orientation. .   38. The method of claim 37, wherein at least one of the first magnetic field, the second magnetic field, and the third magnetic field is delivered for at least 10 seconds before the delivery orientation is changed to a different orientation. .   38. The method of claim 37, wherein at least one of the first magnetic field, the second magnetic field, and the third magnetic field is delivered for at least 30 seconds before the delivery orientation is changed to a different orientation. .   38. The method of claim 37, wherein at least one of the first magnetic field, the second magnetic field, and the third magnetic field is delivered for 300 seconds or less before the delivery orientation is changed to a different orientation. .   38. The method of claim 37, wherein two of the first magnetic field, the second magnetic field, and the third magnetic field are delivered simultaneously.   38. The method of claim 37, wherein the magnetic field is delivered to the body for a total of about 30 minutes to about 60 minutes.   38. The method of claim 37, wherein the target comprises cancer cells.   38. The method of claim 37, wherein the target comprises heart tissue.   AC current flowing through at least one of the first coil, the second coil, and the third coil is at least another of the first coil, the second coil, and the third coil. 38. The method of claim 37, wherein the AC current flowing through one is about 90 degrees out of phase.   AC current flowing through at least one of the first coil, the second coil, and the third coil is at least another of the first coil, the second coil, and the third coil. 38. The method of claim 37, wherein the AC current flowing through one is out of phase from about 60 degrees to about 120 degrees. A device for delivering an electric field to the body, the device comprising:
Means for delivering a first magnetic field from a first coil to the body in a first orientation directed to a desired target in the body;
Means for delivering a second magnetic field from a second coil in a second orientation toward the desired target in the body to induce an electric field across the desired target; and
Means for alternating current flow between the first coil and the second coil;
Including the device.   53. The apparatus of claim 52, wherein at least one of the first coil and the second coil comprises a coil pair.   53. The apparatus of claim 52, further comprising means for delivering a third magnetic field from the third coil in a third orientation.

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