JP6116157B2 - Device feeding device, in-body device feeding device, and in-body device feeding method - Google Patents

Description

The present invention, non-contact device supply electric location of feed at relates vivo device power supply apparatus and the body device power supply method for supplying power from the endoscope capsule and organ sensors like outside the body device in the body to the device.

  Conventionally, the electric power supply apparatus described in patent document 1 is known. This power supply device supplies power to a capsule endoscope, which is a device introduced into a human body, in a non-contact manner from outside the human body. Specifically, an AC magnetic field generated from a power transmission coil wound around a human body acts on a power receiving coil provided in a capsule endoscope inside the body, and the power receiving coil on which the AC magnetic field acts The alternating current generated in this way is used to supply power to each part of the capsule endoscope.

JP 2007-105218 A

  In the power supply device (power supply device) as described above, for receiving power that is extremely small, such as being wound around a human body, an alternating magnetic field generated by a relatively large power transmission coil is provided in the capsule endoscope in the body. In order to act on the coil, the power transmission efficiency is generally not good, and it is desired to improve it.

  The present invention has been made in view of such circumstances, and an apparatus power supply apparatus and an apparatus power supply method capable of supplying power to a device in a non-contact manner as efficiently as possible, and further to a device in the body as much as possible. It is an object of the present invention to provide an in-vivo device power supply device that can efficiently supply power from outside the body.

In addition, the in-vivo device power supply device according to the present invention includes a first resonator including a first coil that is a spiral coil, and a predetermined connection to the first coil without being connected to the first coil. And a second resonator including a second coil which is a spiral coil arranged coaxially at a distance of the first resonance in a state where an alternating current is supplied to the first coil. And a second resonator that magnetically couples and resonates, and a power source that supplies the alternating current to the first coil, the first coil and the second Via a third resonator which is disposed opposite to the animal body with the predetermined distance therebetween and is magnetically coupled to the coupled resonator provided in a device introduced into the animal body. The power is supplied to the device.

With such a configuration, when an alternating current is supplied to the first coil in the coupled resonator, the alternating current is applied to the second coil that is coaxially disposed opposite to the first coil by a predetermined distance. Even if no current is supplied, the first resonator including the first coil and the second resonator including the second coil are magnetically coupled to resonate. As a result, the animal body between the first coil and the second coil that are opposed to each other with the predetermined distance across the animal body has a magnetic field generated by the first resonator, A magnetic field generated by the two resonators is superimposed to generate a combined magnetic field. And the 3rd resonator provided in the apparatus (for example, capsule type endoscope) introduced into the inside of the body is magnetically coupled with the above-mentioned coupling resonator (the 1st resonator and the 2nd resonator). Thus, electric power that can be generated based on the electromagnetic action of the third resonator with the combined magnetic field is supplied to the device (for example, a capsule endoscope). And since the 1st coil and the 2nd coil are comprised by the flat spiral coil, it is easy to arrange these 1st coils and the 2nd coil oppositely across the animal's body.

Further, engagement Ru equipment power supply device according to the present invention includes a first resonator including a first coil, without being connected to the first coil, a predetermined distance away relative to the first coil And a second resonator including a second coil disposed coaxially and oppositely, and in a state where an alternating current is supplied to the first coil, the first resonator and the second resonator A coupled resonator that is magnetically coupled to the resonator and resonates; and a power source that supplies the alternating current to the first coil; and the first coil that is disposed correspondingly in the coupled resonator; Power is supplied to the device via a third resonator provided in a device disposed between the second coil and magnetically coupled to the coupled resonator, and the coupled resonator includes the first resonator. and the resonator and the second resonator is configured to resonate with the odd mode frequency.

  With such a configuration, since the combined magnetic field strength between the first coil and the second coil becomes relatively large, power can be efficiently supplied to the device via the third resonator.

  According to the present invention, two resonators (a first resonator and a second resonator) are supplied by supplying an alternating current (energy) to a single resonator (a first coil of the first resonator). ) Is supplied to the device (device introduced into the body) based on the combined magnetic field, so that the device can be more efficiently contactlessly powered.

It is a figure which shows the basic composition of the in-body apparatus electric power feeder which concerns on embodiment of this invention. The subject (person) of the first pad in which the first power supply side coil of the first power supply side resonator and the second pad in which the second power supply side resonator are stored in the in-body power supply device shown in FIG. It is a figure which shows the example of arrangement | positioning. It is a circuit diagram which shows a part of electric power feeding circuit provided in an in-vivo apparatus. It is a figure which shows an example of the odd mode frequency fodd and the even mode frequency fevn. It is a figure which shows notionally the synthetic | combination magnetic field Hc and the synthetic | combination electric field Ec which are produced | generated by two coils R1, R2 (resonator) at the time of resonating with an even mode frequency. It is a figure which shows notionally the synthetic | combination magnetic field Hc and the synthetic | combination electric field Ec which are produced | generated by two coils R1, R2 (resonator) at the time of resonating with an odd mode frequency. In odd mode resonance, it is a figure which shows notionally the magnetic field H1 produced | generated by the 1st electric power feeding side coil, the magnetic field H2 produced | generated by the 2nd electric power feeding side coil, and those synthetic magnetic fields Hc. It is a figure which shows a coupling | bonding microstrip resonator (open ring resonator). It is a figure which shows a coupling | bonding microstrip resonator (multi-open ring resonator). It is a figure which shows a coupling | bonding microstrip resonator (spiral resonator). It is a figure which shows the LTCC quadruple microstrip interdigital resonator. It is a figure which shows notionally the magnetic field distribution of odd mode notionally. It is a figure which shows notionally the electric field distribution of odd mode. It is a figure which shows notionally magnetic field distribution notionally. It is a figure which shows the electric field distribution of even mode notionally. It is a figure which shows a basic spiral coil. It is a figure which shows a single resonator. It is a figure which shows a split resonator. It is a figure which shows a dual resonator. It is a figure which shows the magnetic field distribution (simulation) on the central axis of a single, a division | segmentation, and a dual resonator. It is a figure which shows the electric field amplitude distribution (simulation) on the central axis of a single, a division, and a dual resonator at the time of odd mode resonance. It is a figure which shows the change (resonance frequency is 1 MHz) (simulation) of the inductance L by the coil winding number n, and the capacity | capacitance C which should be added. It is a figure which shows the change (resonance frequency is 1 MHz) (measurement) of the inductance L by the coil winding number n, and the capacity | capacitance C which should be added. It is a figure which shows the change (measurement) of the no-load Q by the number of coil turns. It is a figure which shows the shape of a receiving coil. It is a figure which shows the influence (simulation) on the coupling coefficient of the number of coil turns. It is a figure which shows the influence (measurement) on the coupling coefficient of the number of coil turns. It is a figure which shows the type which changed one side of the dual resonator to the solenoid. It is a figure which shows distribution (simulation) on the central axis of the coupling coefficient of a spiral-solenoid coupling dual resonator. It is a figure which shows the lowest mode resonance frequency (measurement) of the dual resonator with respect to the space | interval of a spiral coil. It is a figure which shows how to wind the spiral coil which increases the uniformity of magnetic field distribution. It is a figure which shows the magnetic field distribution (simulation) of a uniform winding dual spiral resonator. It is a figure which shows the magnetic field distribution (simulation) of a non-uniform winding dual spiral resonator. It is a figure which shows the coupling coefficient (simulation) of the non-uniform winding dual spiral resonator and the receiving coil placed on the central axis.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The in-vivo device electric power feeder which concerns on embodiment of this invention is comprised as shown in FIG.

  In FIG. 1, the in-vivo device power supply apparatus includes a first power supply side resonator 10 (first resonator) and a second power supply side resonator 20 (second resonator). The first power supply side resonator 10 is configured by an LC circuit including a first power supply side coil 11 (first coil) and a capacitor 12 formed by a spiral coil having a predetermined number of turns. In this LC circuit, an AC power supply 13 is connected in series to a first power supply side coil 11 and a capacitor 12, and the first power supply side coil 11 and the capacitor 12 (the first power supply side resonator 10 are connected from the AC power supply 13. ) Is supplied with an alternating current.

  Similar to the first power supply side resonator 10, the second power supply side resonator 20 includes a second power supply side coil 21 (second coil) formed by a spiral coil having a predetermined number of turns, a capacitor 22, and the like. It is comprised by LC circuit containing. Unlike the first power supply side resonator 10, an AC power source is not connected to this LC circuit.

  The LC circuit including the first feeding side coil 21 and the capacitor 12 in the first feeding side resonator 10 is housed in a flat first pad 110, and the second feeding in the second feeding side resonator 20. The LC circuit including the side coil 21 and the capacitor 22 is also accommodated in the flat second pad 120. For example, as shown in FIG. 2, the first pad 110 is placed at a position facing the back of the subject (person) HMN in the bed 200, and the second pad 210 is separated from the first pad 110 by a predetermined distance A. It is placed facing the abdomen of the subject HMN. As a result, the first power supply side coil 11 in the first pad 110 and the second power supply side coil 21 in the second pad 120 are coaxially opposed to each other with a predetermined distance A therebetween. Then, with the alternating current from the alternating current power supply 13 being supplied to the first power supply side coil 11, the first power supply side resonator 10 and the second power supply side resonator are magnetically coupled to resonate. Thus, the inductance L of the first power supply side coil 11, the capacity of the capacitor 11, the inductance L of the second power supply side coil 21, and the capacity of the capacitor 21 are determined. The first feeding side resonator 10 and the second feeding side resonator 20 that are magnetically coupled and resonated in this way constitute a coupled resonator.

  A power receiving side resonator 30 (third resonator) including a power receiving side coil 31 is provided in an in-vivo device (for example, capsule endoscope, organ sensor) 100 introduced into the body of a subject (person) HMN. . As shown in FIG. 3, the power receiving side resonator 30 is formed of an LC circuit including a power receiving side coil 31 (solenoid, spiral coil, etc.) and a capacitor 32. In the in-vivo device 100, the alternating current generated by the power receiving resonator 30 is rectified by the rectifier circuit 33 and supplied (powered) to each part as a direct current.

  Incidentally, in general, as a mode in which two resonators (coils) are electromagnetically coupled and resonated, for example, as shown in FIG. 4, an even mode that resonates at a relatively high frequency fevn (referred to as an even mode frequency), and There is an odd mode that resonates at a relatively low frequency fodd (referred to as odd mode frequency). When two resonators resonate in the even mode, the region between the coils R1 and R2 of these resonators has a negative value (minimum value) at the position of one coil R1, as shown in FIG. 5A. As a result, a combined magnetic field Hc that is monotonically increased and has a maximum value (positive value) at the position of the other coil R2 is formed, and a positive value is obtained at both the position of one coil R1 and the position of the other coil R2. Thus, a combined electric field Ec having a minimum value at the center of the two coils R1 and R2 is formed. When two resonators resonate in an odd mode, the region between the coils R1 and R2 of the resonators has a position of one coil R1 and a position of the other coil R2, as shown in FIG. 5B. A combined magnetic field Hc having a minimum distribution at the center of the two coils R1 and R2 is formed, and a negative value (minimum value) is monotonically increased at the position of one coil R1. Thus, a combined electric field Ec having a maximum value (positive value) at the position of the other coil R2 is formed.

  The intracorporeal device power supply apparatus according to this embodiment sends power to the intracorporeal device 100 introduced into the subject HMN by a synthesized magnetic field generated by resonance between the first power supply resonator 10 and the second power supply resonator 20. Therefore, the inductance L of the first feeding side coil 11, the capacitance of the capacitor 11, the inductance L of the second feeding side coil 21, and the capacitance of the capacitor 21 are set so as to give the same resonance frequency. The frequency of the power supply 13 is set to be equal to the odd mode frequency fodd formed by the coupling of the first power supply side resonator 10 and the second power supply side resonator 20.

  In the in-vivo device power supply apparatus configured as described above, when an alternating current from the alternating current power supply 13 is supplied to the first power supply side coil 11, it is coaxial with a predetermined distance A from the first power supply side coil 11. The first feeding-side resonator 10 including the first feeding-side coil 11 and the second feeding-side coil 21 are not particularly supplied with the second feeding-side coil 21 that is disposed in a regular manner. The second power-feeding-side resonator 20 that is included is magnetically coupled to resonate in an even / odd mode. Therefore, by adjusting the power source frequency to the odd mode frequency (fodd), the subject HMN between the first power supply side coil 11 and the second power supply side coil 21 that are opposed to each other with a predetermined distance A across the subject HMN. 6, the magnetic field H1 generated by the first power supply resonator 10 (first power supply coil 11) and the second power supply resonator 20 (second power supply coil) are formed. 21) is superimposed on the magnetic field H2 generated by 21) to generate a combined magnetic field Hc having a relatively large intensity. Thereby, the power receiving side coil 31 of the power receiving side resonator 30 provided in the in-vivo device in the body of the subject HMN is, for example, as shown in FIG. 1, the first power feeding side coil 11 and the second power feeding side coil. 21 is placed in a synthetic magnetic field Hc formed with a relatively high strength.

  The power receiving side resonator 30 constituted by the LC circuit of the power receiving side coil 31 and the capacitor 32 is magnetically coupled to the coupling resonator (the first power feeding side resonator 10 and the second power feeding side resonator 20). Is coupled to the LC circuit of the power receiving side coil 31 and the capacitor C constituting the power receiving side resonator 30 based on the electromagnetic action of the power receiving side coil 31 (power receiving side resonator 30) with the synthetic magnetic field Hc. An electric current is generated. In the in-vivo device 100, the alternating current generated in the LC circuit is rectified by the rectifying circuit 33 and supplied (powered) to each part as a direct current.

  According to the in-vivo device power feeding device according to the embodiment of the present invention as described above, the first power feeding is performed by supplying the alternating current (energy) to the first power feeding resonator 10 (single resonator). Since the electric power based on the combined magnetic field Hc (see FIG. 6) having a relatively high strength by the two resonators of the side resonator 10 and the second power supply side resonator 20 is supplied to the internal device 100, the internal device 100 In contrast, power can be supplied in a non-contact manner more efficiently.

  The present invention is not limited to the above-described in-vivo device power supply device, but can be embodied as a device power supply device that supplies power to a device in a non-contact manner.

  Further, each of the first power supply side coil 11 and the second power supply side coil 21 is formed of a spiral coil, but is not limited thereto, and these are other types of coils, for example, solenoid coils. They may also be different types of coils (one is a spiral coil, the other is a solenoid coil, etc.). However, when each of the first power supply side coil 11 and the second power supply side coil 21 is formed of a spiral coil, the first power supply side coil 11 and the second power supply side coil 21 have a flat shape. The first pad 110 and the second pad 120 (see FIG. 2) for accommodating the first pad 110 and the second pad 120 can be formed flat, and the first pad 110 and the second pad 120 can be easily arranged to face each other across the body of the subject HMN. As a result, the first power supply side coil 11 and the second power supply side coil 21 are easily arranged to face each other with the body of the subject HMN interposed therebetween.

  In addition, this inventor made the apparatus electric power feeder (in-body apparatus electric power feeder) which concerns on this invention based on experiment and consideration which are demonstrated below with reference to FIG. 7A-FIG. The dual resonator described below is used in a device power supply device (in-body device power supply device) according to the present invention.

でありｎが大きいときｌは巻き数に比例するとしてよい。自己インダクタンスＬは一次近似の範囲ではコイル長に比例するはずなので図１３Ａ及び図１３ＢのＬは直線になると予想される。しかし現実にそうはなっていないのはコイル巻線間の相互インダクタンスおよび線間容量が等価的に全インダクタンスに寄与しているためと考えられる。一方コイル抵抗Ｒはもし近接効果が小さければコイル長に比例するので、この共振器の無負荷Qは

であることから巻数の増加とともにQは増加することが期待できる。図１４に巻数に対する無負荷Qの測定結果を示してあるが予測どおりに増大しており、伝送効率が結合係数と無負荷Qに支配されることを考えると、この特性は実用上重要である。
次に図１５のような小さい受電コイルを用意して、結合係数がコイル巻き数の影響を受けるかどうかを調べる。結合係数は基本的にコイル直径で決まる[5]ことを考えるとほとんど巻き数の影響はないと予想されるが、図１６のシミュレーション結果はそれを裏付けるものである。図１６では送電用として図１１Ｃのデュアルスパイラル共振器の基本モードを仮定して、別のループプローブと疎結合状態にして計算した。また、２つのスパイラルコイルの外側を利用することも有るかもしれないので外側の結果も示している。
シミュレーションに加えて上記共振器を実際に製作して実験を行った結果を図１７に示す。デュアルスパイラル共振器の巻数をパラメータとした図１６に対応する測定結果は巻数の少ないときはシミュレーションより小さいが、巻数の増加に従って明らかに結合係数が増加し、シミュレーション値に近づいている。その理由は今のところ不明である。
（２）ソレノドコイルの導入
ソレノイドコイルは同じ直径のスパイラルコイルに比べてより遠方まで磁界が強度を保つことが知られている[5]。そこで図１８のように片方だけをソレノイドコイルに置き換えてデュアル共振器を構築し、中心軸上の磁界分布をWIPL-Dで計算したところ図１９のような結果が得られた。ソレノイドコイルの巻数は２０回としその奥行きｔは２０〜５０mmと変えて図１５と同じ直径３cm、巻数２５回の単一スパイラルコイルを受電用に使用した。ソレノイドコイルはｚ=１０cmの場所にその左端面がおかれているが、受電コイルの直径は小さく、ソレノイドコイルの直径が３０cmあるため内部を貫通して受電コイルを移動できる。その結果ｚ=２０cmまでデータが示されている。
図１９の結果は図１６に比べて結合係数が減少しあまり好ましくない。半径方向の変化を確認したうえで何らかの改善することは今後の課題である。
（３）コイル間隔
デュアル共振器を形成する2つのスパイラルコイルの間隔が何らかの理由で変わると共振周波数も変わって具合が悪いのでその影響を調べておく必要がある。実験によってそれを確認したので図２０に示す。この結果からコイル直径程度に共振器が離れていれば共振周波数シフトは問題とするほど大きくないことが分かる。
５．結合係数の空間的一様性の向上
同一のスパイラルコイルを２個用いることは変わらないが、巻き方を工夫して磁界分布の空間一様性を高めることによって結合係数の一様性を高める事が出来る。各コイルは従来の一様巻きに対して、図２１のように円形を方形に変更し、エッジ部は従来どおり一様であるが、中心部は次第に疎に巻くようにする。この根拠は図１１Ａ〜図１１Ｃのように一様巻きの場合には図２２に示すように中心軸方向、半径方向ともに磁界分布（方向は無視して振幅のみの分布）が非一様となるからである。
最も強い箇所の強度を減らすような巻き方の一つとして図２１のような巻き方を考えた。図２２において各曲線はコイル中心軸から半径方向にｒだけ位置をずらし、その値を保ったままコイル軸に平行に観測点をずらせて磁場強さを計算した結果である。また図２３においては、同じく中心軸からコイル外形に平行にｄだけ位置をずらせて同じ計算を行った。
図２３によると一番外側であるｄ=１５cm以外の曲線は図２２に対して非常に一様性が向上していることが分かる。ｄ=１０cm以下の範囲に限れば図２２では場所によって１０倍の磁界強度差があるのに対して、図２３では３倍にまで減少していて、一様化が実現していることが分かる。
その結果として図１６と同様に図１５のコイルを用いて結合係数を計算してみると、図２４のように一様巻きに比べて大幅な一様化を達成することが出来た。ただしこの結果は全体として結合係数を若干減らすマイナス面を持っているが、磁界の一様化は伝送効率一様化に直接つながり応用上重要である。
６．結論
マイクロ波BPF作製時に小型化の有力な手段として提案した結合共振器という概念を別の目的、すなわち共振器電磁界の増強と一様化に役立て、"磁界共鳴型"WPTシステムの伝送効率とその空間的一様性の向上を図った。
向上率は期待したほど大きくはなかったが、少しの向上であっても他の方法と組み合わせて積み上げることによって、大きな効果へと高められると考えている。

文 献
[1] 山本卓史, 粟井郁雄, 真田篤志, 久保洋, "プリント回路基板両面に作製された2重結合共振器とその応用,"電子情報通信学会論文誌,J87-C, No. 12,1045-1052, 2004 年12月
[2] Ikuo Awai, "Wide Band Spurious Suppression of Multi-Strip Resonator BPF -Comprehensive Way to Suppress Spurious Responses in BPFs-", IEICE Trans. Electron., Vol. E93-C, No 7, pp.942-948, July 2010,invited.
[3] Wei Wei，Yoshiaki Narusue，Yoshihiro Kawahara，Naoki Kobayashi，Hiroshi Fukuda，Tsuneo Tsukagoshi，Tohru Asami，" Characteristic Analysis on Double Side Spiral Resonator's Thickness Effect on Transmission Efficiency-Distance Feature for Wireless Power Transmission"、信学技報WPT2012-01, 2012年5月．
[4] Ikuo Awai, "New expressions for coupling coefficient between resonators", IEICE Trans. Electron., E88-C, No.12, pp.2295-2301, Dec. 2005.
[5] Toshio Ishizaki, Takuya Komori, Tetsuya Ishida and Ikuo Awai, "Comparative study of coil resonators for wireless power transfer system in terms of transfer loss", IEICE Electronics Express, Vol. 7, No. 11, pp. 785-790, June, 2010. 1. Preface Among the wireless power transfer (WPT) systems, the "magnetic resonance type" is suitable for near / medium-distance transmission. Increasing the transmission efficiency and improving the spatial uniformity of efficiency are important for expanding the application range of the system. It is. We propose a new structure called dual resonator as one way to achieve the purpose using multiple coupled resonators. The same structure has already been proposed by several groups, but the purpose of use is different from that of this report [1]-[3]. There are no examples. As the name implies, this resonator is formed by two resonators, and the two have the same resonance frequency. When two or more resonators are brought close to each other, they are coupled to each other, and the resonance frequency is known to be divided into as many as the number of resonators. If two resonators are used, so-called even mode / odd mode is obtained. Split.
At this point, the two resonators can be regarded as being integrated [1], [2], which are called dual resonators and used for power transmission. Since the even-odd mode has different frequencies, the lower odd mode can be considered as the basic mode, and the higher even mode can be considered as the higher-order mode. If another resonator is introduced and used on the power receiving side, the two are coupled in accordance with the odd mode frequency to form a WPT transmission circuit. In this report, a dual spiral resonator is used to increase the transmission efficiency and spatial uniformity of the WPT system.
2. Characteristics of coupled resonators One of the authors has previously proposed the use of resonators based on the above ideas for band-pass filter (BPF) miniaturization [1], [2]. In Reference 1, a normal resonator is fabricated on the upper surface of a printed circuit board, and the same type of resonator is added to the lower ground surface, as shown in FIGS. 7A to 7B. In Reference 2, low temperature co-sintered ceramics (LTCC) is used. A multilayer interdigital strip resonator as shown in FIG. Since these are composed of strip conductor resonators that are spread side coupled to each other, the resonance frequency is largely split up and down by strong coupling. Therefore, if the lowest frequency is used as the basic mode for the BPF, it contributes to miniaturization of the circuit and low spurious.
However, this report uses another aspect of the coupled resonator. It focuses on the electromagnetic field distribution formed by two coupled resonators as shown in FIGS. 9A to 9D. As described above, even and odd modes are generated by mutual coupling when the same spiral resonators are arranged symmetrically. However, it is known that the electromagnetic field distribution is analyzed as shown in FIGS. 9A to 9D by the coupled mode theory. [Four]. Approximately, in the odd mode, the magnetic field formed by coupling is the sum of the resonator fundamental modes, and the electric field is the difference. On the other hand, the opposite is true in even mode.
In the magnetic field coupled resonator type ("magnetic field resonance") WPT system, the magnetic field distribution is important and the electric field distribution does not contribute much to the coupling, so it can be seen from FIGS. 9A to 9D that the odd mode is preferably used. When the power receiving resonator is placed between the power transmitting resonators R1 and R2, a magnetic field twice as large as that of the single resonator can be obtained in the central portion that gives the lowest magnetic field strength, so that the transmission efficiency is expected to double. .
3. Electromagnetic field distribution In order to clarify the characteristics of the dual resonator, the representative structures shown in FIGS. 10 and 11A to 11B are compared and examined. FIG. 11A is a normal spiral resonator in which a capacitor is added in series to the basic spiral coil of FIG. 10 and is called a single resonator. In FIG. 11B, two basic spiral coils are connected in series at an appropriate interval, and a common capacitor is added in series to resonate. This is called a split resonator. FIG. 11C places and couples the two single resonators of FIG. 11A in opposition. Therefore, one of them is powered from the outside, while the other has the feature that no wiring is required. As described above, FIG. 11C has two resonance frequencies, but only the lower mode (odd mode) is used.
The intensity distribution along the resonator axis of the electromagnetic field formed by the three structures was calculated by the electromagnetic field simulator WIPL-D, and the results of FIGS. 12A and 12B were obtained. The coordinate axis was determined by setting the distance between the two spiral coils constituting the split resonator and dual resonator to 20 cm, and setting the center axis to 0, so that the coordinates of the single resonator were set at −10 cm accordingly. I am doing it.
In the WIPL-D excitation method, 1W of power is input and the reflection coefficient S11 is displayed. Therefore, the excitation loop coil is adjusted so that S11 = -3dB and 3 structures are common. Care was taken to inject into the resonator. As a result, as described above (FIG. 9A), the odd mode of the dual resonator should have double the magnetic field strength at the central point as compared to the single resonator, but it is only about 1.5 times here. ing. In addition, it is preferable that the magnetic field strength of the split resonator is approximately the same as that of the dual resonator.
For reference, the electric field distribution is shown in FIG. 12B, but the negative value in FIG. 9A of the electric field of the dual resonator is changed to a positive value for the absolute value display. Since the electric field of the split resonator is large, it is considered that it does not affect the coupling with the power-receiving resonator, so there is no interest here.
Judging from the electromagnetic field distribution formed as described above, the split resonator and the dual resonator have the same performance, but use the dual resonator having the advantage that it is not necessary to connect the two resonators with a wire. I will do it.
4). Characteristics of Dual Spiral Resonator (1) Influence of the number of coil turns The power used is in the order of mW, so the capacity is chip parts. When the no-load Q value was measured for various capacitance values, it was 2000 or more regardless of the capacitance value, so that the capacity loss may be ignored as compared with a coil having a Q value of several hundreds or less. I examined what happens if the outer shape of the spiral coil is fixed at 30 cm and the number of turns (the pitch also changes simultaneously) is changed. As a result, the inductance changes, and the resonant frequency is fixed at 1 MHz, so that the additional capacitance value naturally changes. 13A and 13B show the results of simulating changes in inductance and additional capacitance with the horizontal axis as the total number of turns of the coil. When the number of turns is n and the radius is r, the total coil length l is almost

And when n is large, l may be proportional to the number of turns. Since the self-inductance L should be proportional to the coil length in the first order approximation range, L in FIGS. 13A and 13B is expected to be a straight line. However, this is not actually the case because the mutual inductance and the line capacitance between the coil windings contribute to the total inductance equivalently. On the other hand, the coil resistance R is proportional to the coil length if the proximity effect is small.

Therefore, Q can be expected to increase as the number of turns increases. FIG. 14 shows the measurement result of the no-load Q with respect to the number of turns, which increases as expected, and considering that the transmission efficiency is dominated by the coupling coefficient and the no-load Q, this characteristic is practically important. .
Next, a small receiving coil as shown in FIG. 15 is prepared, and it is examined whether the coupling coefficient is affected by the number of coil turns. Considering that the coupling coefficient is basically determined by the coil diameter [5], it is expected that there is almost no influence of the number of turns, but the simulation result in FIG. 16 supports this. In FIG. 16, the basic mode of the dual spiral resonator of FIG. 11C is assumed for power transmission, and calculation is performed in a loosely coupled state with another loop probe. The outer results are also shown because the outside of the two spiral coils may be used.
FIG. 17 shows the result of actually manufacturing the resonator in addition to the simulation and conducting an experiment. The measurement result corresponding to FIG. 16 with the number of turns of the dual spiral resonator as a parameter is smaller than the simulation when the number of turns is small, but the coupling coefficient obviously increases as the number of turns increases and approaches the simulation value. The reason is unknown for now.
(2) Introduction of Solenoid Coil Solenoid coils are known to maintain their magnetic field strength farther than spiral coils of the same diameter [5]. Thus, as shown in FIG. 18, a dual resonator is constructed by replacing only one side with a solenoid coil, and the magnetic field distribution on the central axis is calculated with WIPL-D. The result shown in FIG. 19 is obtained. The number of turns of the solenoid coil was 20 and the depth t was changed from 20 to 50 mm, and a single spiral coil having the same diameter of 3 cm and 25 turns as in FIG. 15 was used for power reception. The solenoid coil has a left end face at a location where z = 10 cm. However, since the diameter of the power receiving coil is small and the solenoid coil has a diameter of 30 cm, the power receiving coil can be moved through the inside. As a result, data is shown up to z = 20 cm.
The result of FIG. 19 is less preferable because the coupling coefficient is reduced compared to FIG. It is a future problem to make some improvement after confirming the change in the radial direction.
(3) Coil spacing If the spacing between the two spiral coils forming the dual resonator changes for some reason, the resonance frequency will also change and the condition will be bad. Since it was confirmed by experiment, it is shown in FIG. From this result, it is understood that the resonance frequency shift is not so large as to be a problem if the resonator is separated by about the coil diameter.
5. Improving the spatial uniformity of the coupling coefficient The use of two identical spiral coils remains the same, but improving the uniformity of the coupling coefficient by improving the spatial uniformity of the magnetic field distribution by devising the winding method. I can do it. Each coil is changed from a circular shape to a square shape as shown in FIG. 21 with respect to the conventional uniform winding, and the edge portion is uniform as before, but the center portion is gradually wound sparsely. The reason for this is that in the case of uniform winding as shown in FIGS. 11A to 11C, the magnetic field distribution (distribution of only the amplitude, ignoring the direction) is non-uniform in both the central axis direction and the radial direction as shown in FIG. Because.
As one of the winding methods for reducing the strength of the strongest part, the winding method as shown in FIG. 21 was considered. In FIG. 22, each curve is the result of calculating the magnetic field strength by shifting the position by r in the radial direction from the coil center axis and shifting the observation point parallel to the coil axis while maintaining the value. In FIG. 23, the same calculation was performed by shifting the position by d in the same way from the central axis in parallel with the coil outer shape.
According to FIG. 23, it can be seen that the curves other than d = 15 cm, which is the outermost side, are much more uniform than FIG. If it is limited to the range of d = 10 cm or less, in FIG. 22, there is a magnetic field strength difference of 10 times depending on the location, but in FIG. .
As a result, when the coupling coefficient was calculated using the coil of FIG. 15 as in FIG. 16, it was possible to achieve significant uniformization compared to uniform winding as shown in FIG. However, this result has a negative effect of slightly reducing the coupling coefficient as a whole, but uniforming the magnetic field directly leads to uniform transmission efficiency and is important for application.
6). Conclusion The concept of coupled resonator, which was proposed as an effective means of miniaturization when producing microwave BPF, was used for another purpose, namely, enhancement and equalization of the electromagnetic field of the resonator, and the transmission efficiency of the "magnetic resonance type" WPT system. The spatial uniformity was improved.
Although the improvement rate was not as great as expected, we believe that even a slight improvement can be increased to a great effect by accumulating in combination with other methods.

Literature
[1] Takashi Yamamoto, Ikuo Sakurai, Atsushi Sanada, Hiroshi Kubo, "Double-coupled resonators fabricated on both sides of printed circuit boards and their applications," IEICE Transactions, J87-C, No. 12,1045 -1052, December 2004
[2] Ikuo Awai, "Wide Band Spurious Suppression of Multi-Strip Resonator BPF -Comprehensive Way to Suppress Spurious Responses in BPFs-", IEICE Trans. Electron., Vol. E93-C, No 7, pp.942-948, July 2010, invited.
[3] Wei Wei, Yoshiaki Narusue, Yoshihiro Kawahara, Naoki Kobayashi, Hiroshi Fukuda, Tsuneo Tsukagoshi, Tohru Asami, “Characteristic Analysis on Double Side Spiral Resonator's Thickness Effect on Transmission Efficiency-Distance Feature for Wireless Power Transmission” WPT2012-01, May 2012.
[4] Ikuo Awai, "New expressions for coupling coefficient between resonators", IEICE Trans. Electron., E88-C, No. 12, pp.2295-2301, Dec. 2005.
[5] Toshio Ishizaki, Takuya Komori, Tetsuya Ishida and Ikuo Awai, "Comparative study of coil resonators for wireless power transfer system in terms of transfer loss", IEICE Electronics Express, Vol. 7, No. 11, pp. 785-790 , June, 2010.

  As described above, the device power supply device (internal device power supply device) and the device power supply method according to the present invention have an effect that power can be supplied to the device (internal device) in a non-contact manner as efficiently as possible. Therefore, the present invention is useful as a device power supply apparatus and device power supply method for supplying power to a device in a non-contact manner, and an in-vivo device power supply device for supplying power to an in-vivo device such as an endoscope capsule or an organ sensor in the body from outside the body.

10 1st power supply side resonator (1st resonator)
11 First power supply side coil (first coil)
12 Capacitor 13 AC power supply 20 Second power supply side resonator (second resonator)
22 Capacitor 30 Receiving side resonator (third resonator)
31 Power-receiving coil 32 Capacitor 100 Internal device 110 First pad 120 Second pad 200 Bed

Claims (3)

A first resonator including a first coil that is a spiral coil, and a spiral coil that is coaxially disposed at a predetermined distance from the first coil without being connected to the first coil And a second resonator including a second coil, wherein the first resonator and the second resonator are magnetic in a state where an alternating current is supplied to the first coil. A coupled resonator that couples to and resonates;
A power supply for supplying the alternating current to the first coil;
The first coil and the second coil are opposed to each other with a predetermined distance between the animal body, and are provided in a device introduced into the animal body and magnetically coupled to the coupling resonator. An in-vivo device power supply device that supplies power to the device via a third resonator.   A first resonator that includes a first coil that is a spiral coil, and a spiral that is not connected to the first coil and is coaxially disposed opposite to the first coil by a predetermined distance. A coupled resonator comprising a second resonator comprising a second coil that is a coil;
  The first coil and the second coil are arranged opposite to each other with the predetermined distance between the animal body,
  An alternating current is supplied to the first coil, and the first resonator and the second resonator in the coupled resonator are magnetically coupled to resonate,
  An in-vivo device feeding method for feeding power to a device via a third resonator provided in the device introduced into the animal body and magnetically coupled to the coupled resonator. A first resonator including a first coil, and a second coil that is coaxially disposed opposite to the first coil by a predetermined distance without being connected to the first coil. A second resonator including the second resonator, wherein the first resonator and the second resonator are magnetically coupled to resonate in a state where an alternating current is supplied to the first coil. A resonator,
A power supply for supplying the alternating current to the first coil;
Via a third resonator that is provided in a device arranged between the first coil and the second coil correspondingly arranged in the coupled resonator and is magnetically coupled to the coupled resonator Power the device,
The coupling resonator is a device power supply apparatus configured such that the first resonator and the second resonator resonate with an odd mode frequency.

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