JP2001037735A - Biological impedance measuring instrument - Google Patents
Biological impedance measuring instrumentInfo
- Publication number
- JP2001037735A JP2001037735A JP11211658A JP21165899A JP2001037735A JP 2001037735 A JP2001037735 A JP 2001037735A JP 11211658 A JP11211658 A JP 11211658A JP 21165899 A JP21165899 A JP 21165899A JP 2001037735 A JP2001037735 A JP 2001037735A
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- Prior art keywords
- voltage
- signal
- biological
- current
- electrodes
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- Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、人体の体脂肪量を
検出する体脂肪計等に使用する生体インピーダンス測定
装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bioimpedance measuring device used for a body fat meter for detecting the amount of body fat in a human body.
【０００２】[0002]
【従来の技術】一般に人体のインピーダンスは、複数の
電極を使用して例えば両手間に通電して、４端子法で測
定している。こうして計測した人体のインピーダンス
に、身長や体重などの身体情報を加味することによっ
て、人体の体脂肪量を求めているものである。2. Description of the Related Art In general, the impedance of a human body is measured by a four-terminal method using a plurality of electrodes, for example, by energizing both hands. The body fat mass of the human body is obtained by adding physical information such as height and weight to the impedance of the human body thus measured.
【０００３】図５は、前記人体のインピーダンスを測定
する生体インピーダンス測定装置の構成を示すブロック
図である。生体インピーダンスの測定は、５０ｋＨｚの
正弦波を発振器１から発生させ、この正弦波の電圧を電
圧−電流変換手段２によって定電流化して測定に使用し
ているものである。すなわち、この定電流を生体に接触
する電極３ａ、３ｂから生体に供給して、電極３ａ、３
ｂ間の電圧を差動増幅器４で取り出し、フィルター回路
などで波形を整形して整流器５で直流変換した後、ＡＤ
変換器６でアナログ値をＡＤ変換してデジタル数値とし
て、マイコンからなる演算部７に伝達しているものであ
る。こうして、演算部７が電圧信号から生体インピーダ
ンスＺを演算している。FIG. 5 is a block diagram showing a configuration of a bioelectrical impedance measuring device for measuring the impedance of the human body. In the measurement of the bioelectrical impedance, a 50 kHz sine wave is generated from the oscillator 1, and the voltage of the sine wave is converted into a constant current by the voltage-current conversion means 2 and used for the measurement. That is, the constant current is supplied to the living body from the electrodes 3a and 3b that come into contact with the living body,
After the voltage between the terminals b and b is taken out by the differential amplifier 4, the waveform is shaped by a filter circuit or the like, and the DC is converted by the rectifier 5,
The analog value is AD-converted by the converter 6 and transmitted as a digital numerical value to the arithmetic unit 7 composed of a microcomputer. Thus, the calculation unit 7 calculates the bioelectrical impedance Z from the voltage signal.
【０００４】生体電流Ｉと電極３ａ、３ｂ間の電圧Ｖと
は、Ｚ＝Ｖ／Ｉの関係が成り立っている。従って、電流
Ｉを一定とした時に、電極３ａ、３ｂ間の電圧Ｖを検出
することによって、生体インピーダンスＺを求めること
ができる。演算部７は、前記生体インピーダンスＺと身
長や体重等の身体情報から体内の脂肪量を算出してい
る。The relationship of Z = V / I holds between the bioelectric current I and the voltage V between the electrodes 3a and 3b. Therefore, when the current I is constant, the bioelectrical impedance Z can be obtained by detecting the voltage V between the electrodes 3a and 3b. The calculation unit 7 calculates the amount of fat in the body from the bioelectrical impedance Z and physical information such as height and weight.
【０００５】[0005]
【発明が解決しようとする課題】前記従来の構成の生体
インピーダンス測定装置は、外来ノイズの影響によって
測定誤差が大きいという課題を有している。すなわち、
生体の部位によっては電極間に発生する電圧が小さく、
測定電圧に外来ノイズが加わってしまうものである。The bioimpedance measuring apparatus having the above-mentioned configuration has a problem that a measurement error is large due to the influence of external noise. That is,
Depending on the part of the living body, the voltage generated between the electrodes is small,
External noise is added to the measured voltage.
【０００６】[0006]
【課題を解決するための手段】本発明は、生体電圧検出
手段の検出信号と抵抗電圧検出手段の検出信号とを乗算
手段によって乗算して、高周波発生手段の周波数成分の
みを抽出することによって、外来ノイズの影響を避け
て、高精度の測定ができる生体インピーダンス測定装置
としているものである。According to the present invention, the detection signal of the biological voltage detecting means and the detection signal of the resistance voltage detecting means are multiplied by the multiplying means to extract only the frequency component of the high frequency generating means. This is a bioimpedance measuring device capable of measuring with high accuracy while avoiding the influence of external noise.
【０００７】[0007]
【発明の実施の形態】請求項１に記載した発明は、生体
電圧検出手段の検出信号と抵抗電圧検出手段の検出信号
とを乗算手段によって乗算して、高周波発生手段の周波
数成分のみを抽出することによって、外来ノイズの影響
を避けて、高精度の測定ができる生体インピーダンス測
定装置としているものである。According to the first aspect of the present invention, only the frequency component of the high frequency generating means is extracted by multiplying the detection signal of the biological voltage detecting means and the detection signal of the resistance voltage detecting means by the multiplying means. Thus, a bioimpedance measuring apparatus capable of performing highly accurate measurement while avoiding the influence of external noise is provided.
【０００８】請求項２に記載した発明は、乗算手段は、
高周波電圧発生手段の出力信号と生体電圧検出手段の信
号と抵抗電圧検出手段の信号とを乗算するようにして、
外来ノイズの影響を避けて、高精度の測定ができる生体
インピーダンス測定装置としているものである。According to a second aspect of the present invention, the multiplying means includes:
By multiplying the output signal of the high-frequency voltage generation means and the signal of the biological voltage detection means and the signal of the resistance voltage detection means,
This is a bioimpedance measuring device capable of measuring with high accuracy while avoiding the influence of external noise.
【０００９】請求項３に記載した発明は、生体電圧検出
手段に出力信号の増幅率を切り替える増幅率切り替え手
段を備えて、生体電圧が小さい場合に増幅率を上げるよ
うにして精度の高い測定ができる生体インピーダンス測
定装置としている。According to a third aspect of the present invention, the biological voltage detecting means is provided with an amplification rate switching means for switching an amplification rate of an output signal, so that when the biological voltage is small, the amplification rate is increased to perform highly accurate measurement. It is a bioimpedance measuring device that can be used.
【００１０】請求項４に記載した発明は、乗算手段は、
出力信号をアナログ値からデジタル値に変換するＡＤ変
換手段と、このＡＤ変換手段の基準電圧を切り替える基
準電圧切り替え手段とを備えて、生体電圧が小さい場合
に基準電圧を切り替えるようにして、精度の高い測定が
できる生体インピーダンス測定装置としている。According to a fourth aspect of the present invention, the multiplying means includes:
AD conversion means for converting the output signal from an analog value to a digital value, and reference voltage switching means for switching the reference voltage of the AD conversion means, the reference voltage is switched when the biological voltage is small, the accuracy of It is a bioimpedance measurement device that can perform high measurement.
【００１１】[0011]
【実施例】（実施例１）以下、本発明の第１の実施例に
ついて説明する。図１は、本実施例の構成を示すブロッ
ク図である。本実施例の生体インピーダンス測定装置
は、５０ｋＨｚの正弦波を発生する高周波電圧発生手段
１０と、この高周波電圧発生手段１０の電圧を電流に変
換する電圧−電流変換手段１１と、生体に接触する複数
の電極１２ａ、１２ｂと、電極１２ａ、１２ｂ間を短絡
するスイッチ１３と、前記電極１２ａ、１２ｂに流れる
電流を検出する電流検出抵抗１４と、この電流検出抵抗
１４の電圧を検出する抵抗電圧検出手段１５と、電極１
２ａ、１２ｂ間の生体の電圧を検出する生体電圧検出手
段１６と、この生体電圧検出手段１６と前記抵抗電圧検
出手段１５との信号を乗算して前記高周波発生手段の周
波数成分のみを抽出する乗算手段１７と、この乗算手段
１７の信号から生体のインピーダンスを算出する演算手
段１８とを備えたものである。なお、前記電圧−電流変
換手段１１は本実施例では定電圧回路によって構成して
いるものである。(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described. FIG. 1 is a block diagram illustrating the configuration of the present embodiment. The bioimpedance measuring apparatus according to the present embodiment includes a high-frequency voltage generator 10 that generates a 50 kHz sine wave, a voltage-current converter 11 that converts the voltage of the high-frequency voltage generator 10 into a current, Of the electrodes 12a and 12b, a switch 13 for short-circuiting the electrodes 12a and 12b, a current detecting resistor 14 for detecting a current flowing through the electrodes 12a and 12b, and a resistance voltage detecting means for detecting a voltage of the current detecting resistor 14. 15 and electrode 1
Biological voltage detecting means 16 for detecting the voltage of the living body between 2a and 12b, and multiplication for multiplying the signals of the biological voltage detecting means 16 and the resistance voltage detecting means 15 to extract only the frequency component of the high frequency generating means Means 17 and a calculating means 18 for calculating the impedance of the living body from the signal of the multiplying means 17. In this embodiment, the voltage-current conversion means 11 is constituted by a constant voltage circuit.
【００１２】以下本実施例の動作について説明する。発
振器等によって構成している高周波電圧発生手段１０が
発生する５０ｋＨｚの正弦波の高周波電圧は、電圧−電
流変換手段１１が定電流化する。定電流化された電流
は、電流検出抵抗１４を介して電極１２ａ、１２ｂ間を
流れる。すなわち、例えば電極１２ａが人体の左手に電
極１２ｂが人体の右手に握られているときには、人体の
両手間に５０ｋＨｚの正弦波の電流が流れるものであ
る。抵抗電圧検出手段１５は、電流検出抵抗１４の両端
の電圧を測定し、乗算手段１７に伝達している。また、
生体電圧検出手段１６は、スイッチ１３を介して電極１
２ａ、１２ｂの両端の電圧、すなわち人体の両手間の電
圧を検出し、この信号を乗算手段１７に伝達している。The operation of this embodiment will be described below. The 50 kHz sine wave high frequency voltage generated by the high frequency voltage generating means 10 constituted by an oscillator or the like is converted into a constant current by the voltage-current converting means 11. The constant current flows between the electrodes 12a and 12b via the current detection resistor 14. That is, for example, when the electrode 12a is held by the left hand of the human body and the electrode 12b is held by the right hand of the human body, a sine wave current of 50 kHz flows between both hands of the human body. The resistance voltage detector 15 measures the voltage across the current detection resistor 14 and transmits the voltage to the multiplier 17. Also,
The biological voltage detecting means 16 is connected to the electrode 1 via the switch 13.
The voltage between both ends of 2a and 12b, that is, the voltage between both hands of the human body is detected, and this signal is transmitted to the multiplying means 17.
【００１３】乗算手段１７に伝達される信号は、スイッ
チ１３を閉じている場合は、抵抗電圧検出手段１５が検
出する電流検出抵抗１４の両端の電圧となる。スイッチ
１３が開いた場合は、抵抗電圧検出手段１５の検出電圧
と、生体電圧検出手段１６が検出している人体の両手間
の電圧の両方となる。従って乗算手段１７は、スイッチ
１３が開いているときは、抵抗電圧検出手段１５が検出
している電流検出抵抗１４の両端の電圧Ｖｏ１を演算手
段１８に伝達している。また、スイッチ１３が開いてい
るときは、抵抗電圧検出手段１５の検出電圧Ｖｏ１と、
生体電圧検出手段１６が検出している人体の両手間の電
圧Ｖｏ２の両方の積Ｖｏ３を出力している。このＶｏ３
は、高周波発生手段１０の高周波成分だけとなるもので
ある。換言すれば、電極１２ａ、電極１２ｂ間にノイズ
が乗ったとしても、このノイズ成分は除去されているも
のである。When the switch 13 is closed, the signal transmitted to the multiplying means 17 is a voltage across the current detecting resistor 14 detected by the resistance voltage detecting means 15. When the switch 13 is opened, the detected voltage of the resistance voltage detecting means 15 and the voltage between both hands of the human body detected by the biological voltage detecting means 16 become both. Therefore, when the switch 13 is open, the multiplying means 17 transmits the voltage Vo1 across the current detecting resistor 14 detected by the resistance voltage detecting means 15 to the calculating means 18. When the switch 13 is open, the detection voltage Vo1 of the resistance voltage detection means 15
It outputs the product Vo3 of both the voltages Vo2 between both hands of the human body detected by the biological voltage detecting means 16. This Vo3
Is only the high frequency component of the high frequency generating means 10. In other words, even if noise is present between the electrodes 12a and 12b, this noise component has been removed.
【００１４】演算手段１８は、前記Ｖｏ１を電流検出抵
抗１４で除することによって生体に流れる電流Ｉを求
め、この電流Ｉと前記Ｖｏ３を使用して、人体のインピ
ーダンスを演算するものである。The calculating means 18 calculates the current I flowing through the living body by dividing Vo1 by the current detecting resistor 14, and calculates the impedance of the human body using this current I and Vo3.
【００１５】こうして求めた人体のインピーダンスは、
人体の除脂肪分を代表するものであり、この値を身長や
体重等の身体情報を使用して演算することによって人体
の脂肪量を求めることができるものである。The impedance of the human body thus determined is
It represents the lean mass of the human body, and the fat amount of the human body can be obtained by calculating this value using physical information such as height and weight.
【００１６】以上のように本実施例では、生体のインピ
ーダンスを測定する時に、電流Ｉを常に検出すると共
に、生体間の電圧と電流検出抵抗の電圧とを乗じること
により、ノイズが除去された生体電圧Ｖｏ３を抽出する
ようにしているため、精度の高い生体インピーダンスの
測定装置を実現できるものである。As described above, in the present embodiment, when measuring the impedance of a living body, the current I is always detected, and the voltage between the living bodies is multiplied by the voltage of the current detecting resistor to thereby remove the noise from the living body. Since the voltage Vo3 is extracted, a highly accurate bioimpedance measuring device can be realized.
【００１７】なお、本実施例では、高周波発生手段１０
の出力電圧を５０ｋＨｚの正弦波としているが、１０ｋ
Ｈｚから５００ｋＨｚの正弦波としてもよいものであ
る。すなわち、１０ｋＨｚから５００ｋＨｚの正弦波
は、人体組織を通過しやすい性質を有しているものであ
り、筋肉等が存在しても正確な測定ができるものであ
る。In this embodiment, the high-frequency generating means 10
Output voltage is a 50 kHz sine wave,
It may be a sine wave from Hz to 500 kHz. That is, a sine wave of 10 kHz to 500 kHz has a property of easily passing through a human body tissue, and enables accurate measurement even when a muscle or the like is present.
【００１８】また本実施例では、スイッチ１３を使用し
て電極１２ａ、１２ｂ間を短絡するようにしているが、
例えば電流検出抵抗１４間を短絡するようにスイッチ１
３を配置する構成としても支障はないものである。In this embodiment, the switch 13 is used to short-circuit the electrodes 12a and 12b.
For example, the switch 1 is connected so that the current detection resistor 14 is short-circuited.
There is no problem even in the configuration where 3 is arranged.
【００１９】（実施例２）続いて本発明の第２の実施例
について説明する。図２は、本実施例の構成を示すブロ
ック図である。乗算手段１９に高周波電圧発生手段１０
の信号を伝達するようにしている。(Embodiment 2) Next, a second embodiment of the present invention will be described. FIG. 2 is a block diagram illustrating the configuration of the present embodiment. High frequency voltage generating means 10
The signal is transmitted.
【００２０】以下本実施例の動作について説明する。乗
算手段１９は、高周波発生手段１０の信号Ｖｏ４と抵抗
電圧検出手段１５の電圧信号Ｖｏ１、または生体電圧検
出手段１６の電圧信号Ｖｏ２の信号を乗ずるものであ
る。すなわち、スイッチ１３が閉じている場合は、乗算
手段１９は抵抗電圧検出手段１５の電圧信号Ｖｏ１と高
周波電圧発生手段１０の信号Ｖｏ４とを乗じた信号Ｖｏ
５を出力する。また、スイッチ１３が開いている場合
は、生体電圧検出手段１６の電圧信号Ｖｏ２と高周波発
生手段１０の信号Ｖｏ４の信号とを乗じた信号Ｖｏ６を
出力する。演算手段１８は、前記Ｖｏ５とＶｏ６とから
人体のインピーダンスを演算するものである。The operation of the embodiment will be described below. The multiplying means 19 multiplies the signal Vo4 of the high-frequency generating means 10 by the voltage signal Vo1 of the resistance voltage detecting means 15 or the voltage signal Vo2 of the biological voltage detecting means 16. That is, when the switch 13 is closed, the multiplying means 19 multiplies the voltage Vo1 of the resistance voltage detecting means 15 by the signal Vo4 of the high frequency voltage generating means 10.
5 is output. When the switch 13 is open, a signal Vo6 obtained by multiplying the voltage signal Vo2 of the biological voltage detecting means 16 and the signal Vo4 of the high frequency generating means 10 is output. The computing means 18 computes the impedance of the human body from Vo5 and Vo6.
【００２１】以上のように本実施例によれば、高周波電
圧発生手段１０の信号Ｖｏ４と抵抗電圧検出手段１５の
電圧信号Ｖｏ１、または生体電圧検出手段１６の電圧信
号Ｖｏ２の信号を乗じた信号を使用するようにして、外
来ノイズの影響を低減でき、測定精度の高いインピーダ
ンス測定装置を実現できるものである。As described above, according to the present embodiment, a signal obtained by multiplying the signal Vo4 of the high-frequency voltage generating means 10 by the voltage signal Vo1 of the resistance voltage detecting means 15 or the voltage signal Vo2 of the biological voltage detecting means 16 is obtained. By using it, the influence of external noise can be reduced, and an impedance measuring device with high measurement accuracy can be realized.
【００２２】（実施例３）続いて本発明の第３の実施例
について説明する。図３は本実施例の構成を示すブロッ
ク図である。本実施例では、生体電圧検出手段の増幅率
を切り替える増幅率切り替え手段２０を使用している。Third Embodiment Next, a third embodiment of the present invention will be described. FIG. 3 is a block diagram showing the configuration of the present embodiment. In the present embodiment, an amplification factor switching unit 20 for switching the amplification factor of the biological voltage detection unit is used.
【００２３】以下本実施例の動作について説明する。演
算手段１８が、所定の増幅率を用いて生体電圧検出手段
１６の電圧信号Ｖｏ２を検出する。この生体電圧Ｖｏ２
が設定値より小さい場合は、演算手段１８は増幅率切り
替え手段２０に信号を伝達して、増幅率切り替え手段２
０の増幅率を大きくする。こうして大きな増幅率に切り
替わった後、再度Ｖｏ２を測定するものである。増幅率
切り替え手段２０の増幅率を大きくすると、１ビットあ
たりの電圧分解能が高くなり、電圧検出精度が向上す
る。すなわち増幅率を設定値から２倍にすると、電圧分
解能は２倍になる。このような設定は、例えば臀部間な
どの生体インピーダンスの小さい局部を使用して、生体
インピーダンスを測定する必要があるときに有効なもの
である。The operation of the embodiment will be described below. The calculating means 18 detects the voltage signal Vo2 of the biological voltage detecting means 16 using a predetermined amplification factor. This biological voltage Vo2
Is smaller than the set value, the calculating means 18 transmits a signal to the amplification rate switching means 20 and the amplification rate switching means 2
Increase the amplification factor of 0. After switching to a large amplification factor in this way, Vo2 is measured again. When the amplification factor of the amplification factor switching means 20 is increased, the voltage resolution per bit is increased, and the voltage detection accuracy is improved. That is, when the amplification factor is doubled from the set value, the voltage resolution is doubled. Such a setting is effective when it is necessary to measure the bioimpedance using a local portion having a small bioimpedance such as between the buttocks.
【００２４】以上のように本実施例によれば、生体電圧
Ｖｏ２が小さい場合、増幅率切り替え手段２０が増幅率
を大きくするようにして、検出精度を高めることがで
き、測定精度の高い生体インピーダンス装置が実現でき
る。As described above, according to the present embodiment, when the biological voltage Vo2 is small, the amplification factor can be increased by the amplification factor switching means 20 to increase the detection accuracy, and the bioimpedance with high measurement accuracy can be obtained. The device can be realized.
【００２５】なお、複数の電極によって複数部位の生体
インピーダンスを測る装置においては、低いインピーダ
ンスの部位を測定する電極時に、この電極を切り替える
信号と連動して基準電圧Ｖｒｅｆを切り替えても同様な
効果が得られる。In a device for measuring the bioelectrical impedance of a plurality of parts by using a plurality of electrodes, the same effect can be obtained by switching the reference voltage Vref in conjunction with a signal for switching the electrodes at the time of measuring the low impedance part. can get.
【００２６】（実施例４）続いて本発明の第４の実施例
について説明する。図４は、本実施例の構成を示すブロ
ック図である。本実施例では、ＡＤ変換手段２１と基準
電圧切り替え手段２２とを有している。ＡＤ変換手段２
１は、乗算手段１７の出力信号をアナログ値からデジタ
ル値に変換して、演算手段１８に伝達している。基準電
圧切り替え手段２２は、ＡＤ変換手段２１の変換レベル
を設定する基準電圧を調節するものである。(Embodiment 4) Next, a fourth embodiment of the present invention will be described. FIG. 4 is a block diagram illustrating the configuration of the present embodiment. In the present embodiment, an A / D converter 21 and a reference voltage switching unit 22 are provided. AD conversion means 2
Numeral 1 converts the output signal of the multiplying means 17 from an analog value to a digital value and transmits it to the calculating means 18. The reference voltage switching means 22 adjusts a reference voltage for setting the conversion level of the AD conversion means 21.
【００２７】以下本実施例の動作について説明する。Ａ
Ｄ変換手段２０の基準電圧は、ＡＤ変換手段２０が例え
ば８ビットの設定であるとすれば２8−１番目の信号の
電圧となっているものである。従ってこの基準電圧を大
きく設定すれば、１ビットあたりの電圧分解能が高くな
るものである。本実施例では、演算手段１８が、生体電
圧Ｖｏ２を示すデジタル信号を所定の基準電圧に設定し
たＡＤ変換手段２１から受けたときに、この信号が所定
のレベルよりも低いときは基準電圧切換手段２２を使用
して増幅率を上げるように動作するものである。このた
め本実施例によれば、例えば臀部間などの生体インピー
ダンスの小さい局部を使用して、生体インピーダンスを
測定する必要があるときに有効なものである。The operation of this embodiment will be described below. A
The reference voltage of the D conversion means 20 is the voltage of the 2 8 -1st signal if the AD conversion means 20 is set to, for example, 8 bits. Therefore, if this reference voltage is set to a large value, the voltage resolution per bit is increased. In the present embodiment, when the arithmetic unit 18 receives a digital signal indicating the biological voltage Vo2 from the A / D converting unit 21 set to a predetermined reference voltage, and when this signal is lower than a predetermined level, the reference voltage switching unit 22 to operate to increase the amplification factor. Therefore, according to the present embodiment, the present invention is effective when it is necessary to measure the bioimpedance using a local part having a small bioimpedance such as between the buttocks.
【００２８】以上のように本実施例によれば、生体電圧
Ｖｏ２が小さい場合、ＡＤ変換手段に接続している基準
電圧切換手段２２の設定を大きくすることによって、検
出精度を高めることができ、測定精度の高い生体インピ
ーダンス装置が実現できる。As described above, according to the present embodiment, when the biological voltage Vo2 is small, the detection accuracy can be improved by increasing the setting of the reference voltage switching means 22 connected to the AD conversion means, A bioimpedance device with high measurement accuracy can be realized.
【００２９】[0029]
【発明の効果】請求項１に記載した発明は、高周波電圧
発生手段と、高周波電圧発生手段の電圧を電流に変換す
る電圧−電流変換手段と、生体に接触する複数の電極
と、前記複数の電極間を短絡するスイッチと、前記電極
間に流れる電流を検出する電流検出抵抗と、電流検出抵
抗の電圧を検出する抵抗電圧検出手段と、前記電極間の
電圧を検出する生体電圧検出手段と、生体電圧検出手段
と前記抵抗電圧検出手段の信号を乗算して前記高周波発
生手段の周波数成分のみを抽出する乗算手段と、乗算手
段の信号から生体のインピーダンスを算出する演算手段
とを備えた構成として、外来ノイズの影響を避けて、高
精度の測定ができる生体インピーダンス測定装置を実現
するものである。According to the first aspect of the present invention, there is provided a high-frequency voltage generating means, a voltage-current converting means for converting a voltage of the high-frequency voltage generating means into a current, a plurality of electrodes that come into contact with a living body, and the plurality of electrodes. A switch that short-circuits between the electrodes, a current detection resistor that detects a current flowing between the electrodes, a resistance voltage detection unit that detects a voltage of the current detection resistor, and a biological voltage detection unit that detects a voltage between the electrodes, A multiplying means for multiplying a signal of the biometric voltage detecting means and a signal of the resistance voltage detecting means to extract only a frequency component of the high-frequency generating means, and a computing means for calculating impedance of a living body from a signal of the multiplying means Another object of the present invention is to realize a bioimpedance measuring device capable of performing highly accurate measurement while avoiding the influence of external noise.
【００３０】請求項２に記載した発明は、乗算手段は、
高周波電圧発生手段の出力信号と生体電圧検出手段の信
号と抵抗電圧検出手段の信号とを乗算する構成として、
外来ノイズの影響を避けて、高精度の測定ができる生体
インピーダンス測定装置を実現するものである。According to a second aspect of the present invention, the multiplying means includes:
As a configuration for multiplying the output signal of the high-frequency voltage generation means and the signal of the biological voltage detection means and the signal of the resistance voltage detection means,
An object of the present invention is to realize a bioimpedance measuring device capable of performing highly accurate measurement while avoiding the influence of external noise.
【００３１】請求項３に記載した発明は、生体電圧検出
手段は、出力信号の増幅率を切り替える増幅率切り替え
手段を備えた構成として、生体電圧が小さい場合に増幅
率を上げるようにして精度の高い測定ができる生体イン
ピーダンス測定装置を実現するものである。According to a third aspect of the present invention, the biological voltage detecting means includes an amplification rate switching means for switching an amplification rate of an output signal, and the accuracy is increased by increasing the amplification rate when the biological voltage is small. A bioimpedance measuring device capable of performing high measurement is realized.
【００３２】請求項４に記載した発明は、乗算手段は、
出力信号をアナログ値からデジタル値に変化するＡＤ変
換手段と、このＡＤ変換手段の基準電圧を切り替える基
準電圧切り替え手段とを備えた構成として、生体電圧が
小さい場合に基準電圧を切り替えるようにして、精度の
高い測定ができる生体インピーダンス測定装置を実現す
るものである。According to a fourth aspect of the present invention, the multiplying means includes:
AD conversion means that changes the output signal from an analog value to a digital value, and a configuration including reference voltage switching means for switching the reference voltage of the AD conversion means, when the biological voltage is small, the reference voltage is switched, An object of the present invention is to realize a bioimpedance measuring device capable of performing highly accurate measurement.
【図１】本発明の第１の実施例である生体インピーダン
ス測定装置の構成を示すブロック図FIG. 1 is a block diagram showing a configuration of a bioimpedance measuring apparatus according to a first embodiment of the present invention.
【図２】本発明の第２の実施例である生体インピーダン
ス測定装置の構成を示すブロック図FIG. 2 is a block diagram showing a configuration of a bioimpedance measuring device according to a second embodiment of the present invention.
【図３】本発明の第３の実施例である生体インピーダン
ス測定装置の構成を示すブロック図FIG. 3 is a block diagram showing a configuration of a bioimpedance measuring device according to a third embodiment of the present invention.
【図４】本発明の第４の実施例である生体インピーダン
ス測定装置の構成を示すブロック図FIG. 4 is a block diagram showing a configuration of a bioimpedance measuring apparatus according to a fourth embodiment of the present invention.
【図５】従来例である生体インピーダンス測定装置の構
成を示すブロック図FIG. 5 is a block diagram showing a configuration of a conventional bioimpedance measuring device.
１０ 高周波電圧発生手段 １１ 電圧−電流変換手段 １２ａ 電極 １２ｂ 電極 １３ スイッチ １４ 電流検出抵抗 １５ 抵抗電圧検出手段 １６ 生体電圧検出手段 １７ 乗算手段 １８ 演算手段 １９ 乗算手段 ２０ 増幅率切り替え手段 ２１ ＡＤ変換手段 ２２ 基準電圧切り替え手段 DESCRIPTION OF SYMBOLS 10 High frequency voltage generation means 11 Voltage-current conversion means 12a Electrode 12b Electrode 13 Switch 14 Current detection resistance 15 Resistance voltage detection means 16 Biovoltage detection means 17 Multiplication means 18 Calculation means 19 Multiplication means 20 Amplification rate switching means 21 AD conversion means 22 Reference voltage switching means
───────────────────────────────────────────────────── フロントページの続き (72)発明者 粟屋 加寿子 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 (72)発明者 河本 恭宏 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 Ｆターム(参考） 4C027 AA06 CC01 DD03 EE03 EE06 FF00 FF01 GG00 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kasuko Awaya 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. Term (reference) 4C027 AA06 CC01 DD03 EE03 EE06 FF00 FF01 GG00
Claims (4)
手段の電圧を電流に変換する電圧−電流変換手段と、生
体に接触する複数の電極と、前記複数の電極間を短絡す
るスイッチと、前記電極間に流れる電流を検出する電流
検出抵抗と、電流検出抵抗の電圧を検出する抵抗電圧検
出手段と、前記電極間の電圧を検出する生体電圧検出手
段と、生体電圧検出手段と前記抵抗電圧検出手段の信号
を乗算して前記高周波発生手段の周波数成分のみを抽出
する乗算手段と、乗算手段の信号から生体のインピーダ
ンスを算出する演算手段とを備えた生体インピーダンス
測定装置。A high-frequency voltage generating means, a voltage-current converting means for converting a voltage of the high-frequency voltage generating means into a current, a plurality of electrodes in contact with a living body, a switch for short-circuiting the plurality of electrodes, A current detection resistor that detects a current flowing between the electrodes, a resistance voltage detection unit that detects a voltage of the current detection resistor, a biological voltage detection unit that detects a voltage between the electrodes, a biological voltage detection unit, and the resistance voltage detection A bioimpedance measuring apparatus comprising: multiplying means for multiplying a signal of the means to extract only the frequency component of the high-frequency generating means;
信号と生体電圧検出手段の信号と抵抗電圧検出手段の信
号とを乗算する請求項１に記載した生体インピーダンス
測定装置。2. The bioimpedance measuring apparatus according to claim 1, wherein the multiplying means multiplies an output signal of the high-frequency voltage generating means, a signal of the biological voltage detecting means, and a signal of the resistance voltage detecting means.
を切り替える増幅率切り替え手段を備えた請求項１また
は２に記載した生体インピーダンス測定装置。3. The bio-impedance measuring device according to claim 1, wherein the bio-voltage detecting device includes an amplification factor switching device for switching an amplification factor of an output signal.
デジタル値に変化するＡＤ変換手段と、このＡＤ変換手
段の基準電圧を切り替える基準電圧切り替え手段とを備
えた請求項１から３のいずれか１項に記載した生体イン
ピーダンス測定装置。4. The multiplication means according to claim 1, further comprising: AD conversion means for changing an output signal from an analog value to a digital value; and reference voltage switching means for switching a reference voltage of said AD conversion means. The bioimpedance measuring device according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11211658A JP2001037735A (en) | 1999-07-27 | 1999-07-27 | Biological impedance measuring instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11211658A JP2001037735A (en) | 1999-07-27 | 1999-07-27 | Biological impedance measuring instrument |
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| Publication Number | Publication Date |
|---|---|
| JP2001037735A true JP2001037735A (en) | 2001-02-13 |
Family
ID=16609454
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11211658A Pending JP2001037735A (en) | 1999-07-27 | 1999-07-27 | Biological impedance measuring instrument |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7218961B2 (en) * | 2002-03-19 | 2007-05-15 | Funai Electric Co., Ltd. | Percent body fat measuring apparatus using a half-wave waveform |
| JP2010233861A (en) * | 2009-03-31 | 2010-10-21 | Sanyo Electric Co Ltd | Chair type massage machine |
| US7894887B2 (en) | 2007-03-26 | 2011-02-22 | Denso Corporation | Biosignal measuring equipment |
| US8068906B2 (en) | 2004-06-21 | 2011-11-29 | Aorora Technologies Pty Ltd | Cardiac monitoring system |
| US8233974B2 (en) | 1999-06-22 | 2012-07-31 | Impedimed Limited | Method and device for measuring tissue oedema |
| US8700121B2 (en) | 2011-12-14 | 2014-04-15 | Intersection Medical, Inc. | Devices for determining the relative spatial change in subsurface resistivities across frequencies in tissue |
| US8761870B2 (en) | 2006-05-30 | 2014-06-24 | Impedimed Limited | Impedance measurements |
| US8781551B2 (en) | 2005-07-01 | 2014-07-15 | Impedimed Limited | Apparatus for connecting impedance measurement apparatus to an electrode |
| US9504406B2 (en) | 2006-11-30 | 2016-11-29 | Impedimed Limited | Measurement apparatus |
| US9585593B2 (en) | 2009-11-18 | 2017-03-07 | Chung Shing Fan | Signal distribution for patient-electrode measurements |
| US9615766B2 (en) | 2008-11-28 | 2017-04-11 | Impedimed Limited | Impedance measurement process |
| US9615767B2 (en) | 2009-10-26 | 2017-04-11 | Impedimed Limited | Fluid level indicator determination |
| US9724012B2 (en) | 2005-10-11 | 2017-08-08 | Impedimed Limited | Hydration status monitoring |
| US10307074B2 (en) | 2007-04-20 | 2019-06-04 | Impedimed Limited | Monitoring system and probe |
| US11660013B2 (en) | 2005-07-01 | 2023-05-30 | Impedimed Limited | Monitoring system |
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| US8233974B2 (en) | 1999-06-22 | 2012-07-31 | Impedimed Limited | Method and device for measuring tissue oedema |
| US7218961B2 (en) * | 2002-03-19 | 2007-05-15 | Funai Electric Co., Ltd. | Percent body fat measuring apparatus using a half-wave waveform |
| US8509886B2 (en) | 2004-06-21 | 2013-08-13 | Aorora Technologies Pty Ltd | Cardiac monitoring system |
| US8068906B2 (en) | 2004-06-21 | 2011-11-29 | Aorora Technologies Pty Ltd | Cardiac monitoring system |
| US8781551B2 (en) | 2005-07-01 | 2014-07-15 | Impedimed Limited | Apparatus for connecting impedance measurement apparatus to an electrode |
| US11737678B2 (en) | 2005-07-01 | 2023-08-29 | Impedimed Limited | Monitoring system |
| US11660013B2 (en) | 2005-07-01 | 2023-05-30 | Impedimed Limited | Monitoring system |
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| US9504406B2 (en) | 2006-11-30 | 2016-11-29 | Impedimed Limited | Measurement apparatus |
| US7894887B2 (en) | 2007-03-26 | 2011-02-22 | Denso Corporation | Biosignal measuring equipment |
| US10307074B2 (en) | 2007-04-20 | 2019-06-04 | Impedimed Limited | Monitoring system and probe |
| US9615766B2 (en) | 2008-11-28 | 2017-04-11 | Impedimed Limited | Impedance measurement process |
| JP2010233861A (en) * | 2009-03-31 | 2010-10-21 | Sanyo Electric Co Ltd | Chair type massage machine |
| US9615767B2 (en) | 2009-10-26 | 2017-04-11 | Impedimed Limited | Fluid level indicator determination |
| US9585593B2 (en) | 2009-11-18 | 2017-03-07 | Chung Shing Fan | Signal distribution for patient-electrode measurements |
| US9149225B2 (en) | 2011-12-14 | 2015-10-06 | Intesection Medical, Inc. | Methods for determining the relative spatial change in subsurface resistivities across frequencies in tissue |
| US8700121B2 (en) | 2011-12-14 | 2014-04-15 | Intersection Medical, Inc. | Devices for determining the relative spatial change in subsurface resistivities across frequencies in tissue |
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