JPH0381656A - Distribution measuring method for electric characteristic of body - Google Patents
Distribution measuring method for electric characteristic of bodyInfo
- Publication number
- JPH0381656A JPH0381656A JP1216148A JP21614889A JPH0381656A JP H0381656 A JPH0381656 A JP H0381656A JP 1216148 A JP1216148 A JP 1216148A JP 21614889 A JP21614889 A JP 21614889A JP H0381656 A JPH0381656 A JP H0381656A
- Authority
- JP
- Japan
- Prior art keywords
- distribution
- sample
- measured
- magnetic field
- local
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title description 11
- 230000005684 electric field Effects 0.000 claims abstract description 6
- 238000000691 measurement method Methods 0.000 claims 1
- 238000005259 measurement Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 6
- 230000005284 excitation Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
Landscapes
- Magnetic Resonance Imaging Apparatus (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
この発明は例えば生体等の物体の電気特性、例えばイン
ピーダンス分布、アドミッタンス分布等を測定する方法
に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for measuring electrical characteristics of an object such as a living body, such as impedance distribution, admittance distribution, etc.
［従来の技術及び発明が解決しようとする課題］従来、
生体等の物体のインピーダンス分布、アドミッタンス分
布等を測定する場合には、電位分布若しくは電流分布又
はそれらによる磁界分布を直接することにより測定して
いた。ところが、直接されりずらい物体の内部や測定時
にされれない生体組織を測定することができなかった。[Prior art and problems to be solved by the invention] Conventionally,
When measuring the impedance distribution, admittance distribution, etc. of an object such as a living body, the measurement is performed by directly measuring the potential distribution, current distribution, or magnetic field distribution due to them. However, it has not been possible to measure the inside of an object that is difficult to directly measure or the biological tissue that cannot be measured.
この発明は、かかる問題点を解決するためになされたも
ので、非接触で物体のインピーダンス、アドミッタンス
等の電気特性の分布を測定することを可能にした物体の
電気特性の分布測定方法を提供することを目的とする。This invention was made to solve these problems, and provides a method for measuring the distribution of electrical properties of an object, which makes it possible to measure the distribution of electrical properties such as impedance and admittance of an object without contact. The purpose is to
［課題を解決するための手段］
この発明に係る物体の電気特性の分布測定方法は、被測
定対象物をＭＲ装置又はＭＲＩ装置で観測しつつ、それ
に直流電界を印加し、それに伴って流れる電流の局所分
布により生じる局所磁界の分布を、被測定対象物に含ま
れるスピンの磁気共鳴の分布を解して検出するようにし
たものである。[Means for Solving the Problems] A method for measuring the distribution of electrical properties of an object according to the present invention involves applying a DC electric field to the object to be measured while observing it with an MR device or an MRI device, and measuring the current flowing along with the object. The distribution of the local magnetic field caused by the local distribution of is detected through the distribution of magnetic resonance of spins contained in the object to be measured.
［作 用］
この発明においては、被測定対象物に直流電界を印加し
て、被測定対象物に含まれるスピンの磁気共鳴の分布を
求めて、このスピンの磁気共鳴の分布に基づいて磁界分
布を求める。この磁界分布により電気特性の分布、例え
ばインピーダンス分布、アドミッタンス分布等が求めら
れ、非接触で被測定対象物の電気特性の分布が得られる
。[Function] In this invention, a DC electric field is applied to the object to be measured, the distribution of magnetic resonance of spins included in the object to be measured is determined, and the magnetic field distribution is calculated based on the distribution of magnetic resonance of spins. seek. This magnetic field distribution determines the distribution of electrical properties, such as impedance distribution and admittance distribution, so that the distribution of electrical properties of the object to be measured can be obtained without contact.
［実施例］
第１図はこの発明の一実施例に係る方法を実施するため
の装置の構成図である。図において、（１）はＭＲ装置
又はＭＲＩ装置（以下単にＭＲＩ装置という）、（２）
はそのサンプル架台、（３）はサンプル架台（３）に載
置されたサンプル（１０）に取り付けられた複数の電極
である。（４）は直流電源であり、その両端の電位は電
極（３）に印加される。[Embodiment] FIG. 1 is a block diagram of an apparatus for carrying out a method according to an embodiment of the present invention. In the figure, (1) is an MR device or MRI device (hereinafter simply referred to as an MRI device), (2)
is the sample mount, and (3) is a plurality of electrodes attached to the sample (10) placed on the sample mount (3). (4) is a DC power supply, and the potential at both ends thereof is applied to the electrode (3).
（５〉は分圧用抵抗であり、（６ａ〉〜（６ｒ）は分圧
用抵抗（５〉で分圧された電位を増幅して電極（３）に
印加する増幅器である。(5> is a voltage dividing resistor, and (6a> to (6r) are amplifiers that amplify the potential divided by the voltage dividing resistor (5>) and apply it to the electrode (3).
サンプル架台（２）中のサンプル（ｌＯ〉には、直流電
源（４〉及び増幅器（６ａ）〜（６ｆ）により電極（３
）を介して一方向に−様な電界が印加され、図示のよう
に、電流（又は電気力線）（２０）が分布し、また等電
位線（２１〉も分布する。The sample (lO) in the sample stand (2) is connected to the electrode (3) by a DC power supply (4) and amplifiers (6a) to (6f).
) is applied in one direction, and as shown in the figure, current (or lines of electric force) (20) are distributed, and equipotential lines (21>) are also distributed.
サンプル（ｌＯ）がインピーダンス分布のない−様な導
電性の物体ならば、電流（２０〉は−様に平行となり、
磁界Ｈ８が−様に変化するだけであり、サンプリング（
１０）内で変化は生じない。If the sample (lO) is a -like conductive object with no impedance distribution, the current (20〉) will be parallel to -like,
The magnetic field H8 only changes in a negative manner, and the sampling (
No change occurs within 10).
ところが、サンプル（１０〉の内部にインピーダンス分
布又は導電性分布があると、電流に分布を生じ、従って
磁界にも分布を生じる。磁界に分布を生じると、ＭＲＩ
装置（１）の吸収線のブロービング（広くなる）とか、
出てくる像が歪むといった現象が起きる。However, if there is an impedance distribution or conductivity distribution inside the sample (10), a distribution will occur in the current, and therefore a distribution in the magnetic field.If a distribution occurs in the magnetic field, the MRI
Blobbing (broadening) the absorption line of device (1), etc.
A phenomenon occurs in which the image that emerges is distorted.
第２図は磁界分布の説明図である。厚みＤのある−様な
抵抗率の円板状のサンプル（１０）に一方向の−様な電
流（２０〉を流すと、磁界Ｈ６に肉厚面内に直線状に、
即ち一定の勾配を有する分布が生じる。このサンプル（
１０〉が大量の水分を含んでいると、そのプロトンの共
鳴線の分布は（磁界Ｈ８以外に勾配を与えないとして）
、この磁界Ｈ８の勾配に従って広がる。その広がり具合
は電流の大きさに依存するので、導電率δに比例し、抵
抗率ρに反比例することになる。FIG. 2 is an explanatory diagram of the magnetic field distribution. When a unidirectional -like current (20〉) is passed through a disk-shaped sample (10) with a thickness D and a -like resistivity, a magnetic field H6 flows in a straight line in the thickness plane.
That is, a distribution with a constant slope results. This sample (
10〉 contains a large amount of water, the distribution of its proton resonance line will be (assuming no gradient is given to anything other than the magnetic field H8)
, spreads according to the gradient of this magnetic field H8. Since the degree of spread depends on the magnitude of the current, it is proportional to the conductivity δ and inversely proportional to the resistivity ρ.
また、局所毎にエンコードしてイメージングするには、
上記に加えて、更に通常のＭＲＩ装置の手法と同様にイ
メージをとればよい。そのための簡単な手法としては、
公知の磁場焦点／走査法を用いればよい。In addition, in order to encode and image each locale,
In addition to the above, images may be taken in the same manner as in a normal MRI apparatus. A simple method for this is
A known magnetic field focusing/scanning method may be used.
第３図は局所の導電率δを把握する際の説明図である。FIG. 3 is an explanatory diagram for understanding the local conductivity δ.
図示の局所（３０）の導電率δが回りのそれより大きい
場合には、共鳴線の間隔は大きくなり、そのイメージが
導電率δのイメージとなる。局所〈３０〉の導電率δが
回りのそれより小さい場合にはその逆となり、共鳴線の
間隔は、小さくなる。If the electrical conductivity δ of the illustrated local area (30) is larger than that of the surrounding area, the spacing between the resonance lines becomes large, and the image becomes an image of the electrical conductivity δ. When the local conductivity δ of <30> is smaller than that of the surrounding area, the opposite is true, and the spacing between the resonance lines becomes smaller.
また、被観測面を厚み方向に選択するには、通常の選択
励起法、即ち厚み方向に交番磁界をかけておいて、その
値がＯ又は所定の値の面（個所）を該当するγＨｏ−ω
。の周波数で励起する、という手法を使うことができる
。この選択励起から先、ＦＩＤ信号やリフェーズするス
ピンの信号をひろってイ゛メージにする所は全て通常の
ＭＲＩ装置で行われている手法が使える。その結果、得
られたイメージを検分し、サンプル（ｌＯ）に直流電界
を、かけて、電流を流したときのイメージと流さないと
きのイメージとの相違から電流分布を知ることができ、
そしてインピーダンス分布を知ることができる。In addition, to select the surface to be observed in the thickness direction, use the usual selective excitation method, that is, apply an alternating magnetic field in the thickness direction, and select the surface (location) whose value is O or a predetermined value by the corresponding γHo- ω
. It is possible to use a method of excitation at a frequency of . From this selective excitation onwards, the methods used in normal MRI equipment can be used to collect and image the FID signal and rephased spin signals. As a result, it is possible to inspect the obtained image, apply a DC electric field to the sample (lO), and determine the current distribution from the difference between the image when current is flowing and the image when no current is flowing.
And you can know the impedance distribution.
［発明の効果〕
以上のようにこの発明によれば、被測定対象物のスピン
の磁気共鳴の分布を求めてその電気特性の分布を求める
ようにしたので、生体等の水分を含む物体のアドミッタ
ンス分布、インピーダンス分布等を非接触に、かつ、局
所をブロービングせずに測定できる。[Effects of the Invention] As described above, according to the present invention, the distribution of the spin magnetic resonance of the object to be measured is determined to determine the distribution of its electrical characteristics, so that the admittance of an object containing water such as a living body can be determined. Distribution, impedance distribution, etc. can be measured non-contact and without locally probing.
第１図はこの発明の一実施例に係る方法を実施する装置
の説明図、第２図は肉厚方向の磁界分布の説明図、第３
図は局所の導電率を把握する際の説明図である。
図において、（１）はＭＲＩ装置、（３）は電極１、（
５）は分圧抵抗、（８ａ） 〜（８ｆ）は増幅器、（１
０）はサンプルである。
なお、図中同一符号は同−又は相当部分を示す。FIG. 1 is an explanatory diagram of an apparatus for carrying out a method according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of magnetic field distribution in the thickness direction, and FIG.
The figure is an explanatory diagram for understanding local conductivity. In the figure, (1) is the MRI device, (3) is the electrode 1, (
5) is a voltage dividing resistor, (8a) to (8f) are amplifiers, (1
0) is a sample. Note that the same reference numerals in the figures indicate the same or equivalent parts.
Claims (1)
それに直流電界を印加し、それに伴って流れる電流の局
所分布により生じる局所磁界の分布を、被測定対象物に
含まれるスピンの磁気共鳴の分布を介して検出すること
を特徴とする物体の電気特性の分布測定方法。While observing the object to be measured with an MR device or an MRI device,
Electrical properties of an object characterized in that a direct current electric field is applied thereto, and the distribution of the local magnetic field generated by the local distribution of current flowing therewith is detected via the distribution of magnetic resonance of spins contained in the object to be measured. distribution measurement method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1216148A JPH0381656A (en) | 1989-08-24 | 1989-08-24 | Distribution measuring method for electric characteristic of body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1216148A JPH0381656A (en) | 1989-08-24 | 1989-08-24 | Distribution measuring method for electric characteristic of body |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0381656A true JPH0381656A (en) | 1991-04-08 |
Family
ID=16684033
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1216148A Pending JPH0381656A (en) | 1989-08-24 | 1989-08-24 | Distribution measuring method for electric characteristic of body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0381656A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005009235A1 (en) * | 2003-07-29 | 2005-02-03 | Hamano Life Science Research Foundation | Electric characteristics measuring method and equipment using magnetic resonance imaging method |
-
1989
- 1989-08-24 JP JP1216148A patent/JPH0381656A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005009235A1 (en) * | 2003-07-29 | 2005-02-03 | Hamano Life Science Research Foundation | Electric characteristics measuring method and equipment using magnetic resonance imaging method |
| JPWO2005009235A1 (en) * | 2003-07-29 | 2007-04-19 | 財団法人濱野生命科学研究財団 | Method and apparatus for measuring electrical characteristics using magnetic resonance imaging |
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