JP3079330B2 - High-pass filter for impulse - Google Patents
High-pass filter for impulseInfo
- Publication number
- JP3079330B2 JP3079330B2 JP04135674A JP13567492A JP3079330B2 JP 3079330 B2 JP3079330 B2 JP 3079330B2 JP 04135674 A JP04135674 A JP 04135674A JP 13567492 A JP13567492 A JP 13567492A JP 3079330 B2 JP3079330 B2 JP 3079330B2
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- JP
- Japan
- Prior art keywords
- pass filter
- circuit
- frequency
- input
- characteristic
- 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.)
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- Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)
- Networks Using Active Elements (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、心電図のＱＲＳ波等の
インパルス直後の微小な高域成分を抽出するためのイン
パルス用ハイパスフィルタに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impulse high-pass filter for extracting minute high-frequency components immediately after an impulse such as a QRS wave of an electrocardiogram.
【０００２】[0002]
【従来の技術】図６に示すように、心電図のＱＲＳ波に
は、被検者によってはＱＲＳ波に対して高い周波数成分
の微小振幅のレートポテンシャル１（図では拡大して示
す）がＳ波及びＴ波間に後続する場合がある。その際、
そのモニタのために遮断周波数が５０Ｈｚ程度の通常の
ＣＲ回路を用いたハイパスフィルタで抽出しようとする
と、ＱＲＳ波のフィルタ出力信号の持続振動に隠れて検
出が困難になる場合がある。この原因をステップ入力応
答について考えると、基線復帰時間が遅れて、テール部
分の振幅が微小信号レベルに対して大きくなることに在
る。ハイパスフィルタを二次或は三次のＣＲ回路にして
も依然根本的には解決されなかった。2. Description of the Related Art As shown in FIG. 6, in a QRS wave of an electrocardiogram, a rate potential 1 having a small amplitude of a high frequency component (shown in an enlarged manner in the figure) is an S wave depending on a subject depending on a subject. And between the T-waves. that time,
If an attempt is made to extract with a high-pass filter using a normal CR circuit having a cutoff frequency of about 50 Hz for the monitoring, detection may be difficult due to the continuous oscillation of the filter output signal of the QRS wave. Considering the cause for the step input response, the base line return time is delayed, and the amplitude of the tail portion is larger than the minute signal level. Even if a high-pass filter is replaced by a second-order or third-order CR circuit, it has not been fundamentally solved.
【０００３】[0003]
【発明が解決しようとする課題】本発明は、このような
点に鑑みて、抵抗及びコンデンサ等を用いたアナログ回
路により、インパルスの後縁を急峻に回復させ得る冒頭
に述べた類のインパルス用ハイパスフィルタを提供する
ことを目的とする。SUMMARY OF THE INVENTION In view of the foregoing, an object of the present invention is to provide an impulse signal of the kind described at the beginning which can recover the trailing edge of the impulse sharply by an analog circuit using a resistor, a capacitor, and the like. An object is to provide a high-pass filter.
【０００４】[0004]
【課題を解決するための手段】本発明は、この目的を達
成するために、インパルスが入力し、かつ必要な遮断周
波数よりも高い遮断周波数のＣＲの微分回路よりなる入
力用ハイパスフィルタと、必要な遮断周波数のステップ
応答特性の傾斜で始まり、かつ実質的に零レベルに達す
る経過時間が半分になる目標ステップ応答特性に対する
入力用ハイパスフィルタのステップ応答特性の振幅差に
対応する補償信号を発生する補償信号発生回路と、入力
ハイパスフィルタの出力信号と補償信号とを加算する加
算回路とを備え、補償信号発生回路は、入力用ハイパス
フィルタの出力信号を入力とする第１の積分回路と、こ
の積分回路の出力信号の積分を行う第２の積分回路とを
有すると共に、第２の積分回路の出力信号は第１の積分
回路の積分コンデンサの入力端子と反対側の端子に帰還
され、第１及び第２の積分回路の出力信号の振幅調整及
び第１の積分回路の出力信号から第２の積分回路の出力
信号の減算により補償信号を発生させることを特徴とす
る。In order to achieve this object, the present invention provides an input high-pass filter comprising a CR differentiating circuit to which an impulse is input and which has a cut-off frequency higher than a required cut-off frequency. A compensation signal corresponding to the amplitude difference between the step response characteristic of the input high-pass filter and the target step response characteristic which starts with the slope of the step response characteristic of a low cut-off frequency and halves the elapsed time to substantially zero level is generated. A compensation signal generation circuit; an addition circuit for adding the output signal of the input high-pass filter and the compensation signal; the compensation signal generation circuit including a first integration circuit that receives the output signal of the input high-pass filter as an input; A second integration circuit that integrates an output signal of the integration circuit, and an output signal of the second integration circuit is integrated by an integration capacitor of the first integration circuit. The compensation signal is fed back to the terminal opposite to the input terminal of the first integration circuit by adjusting the amplitudes of the output signals of the first and second integration circuits and subtracting the output signal of the second integration circuit from the output signal of the first integration circuit. Is generated.
【０００５】[0005]
【作用】入力インパルスは、入力用ハイパスフィルタの
通過時に、必要な遮断周波数特性よりも高い遮断周波数
特性に相応して遮断周波数近辺の成分も過剰にカットさ
れる。この間、補償信号発生回路では、第２の積分回路
においては第１の積分回路の出力信号の積分により遮断
周波数に対して遮断領域側の低域成分が相対的に大きな
振幅で発生される。第１の積分回路の出力信号は、第２
の積分回路の出力信号が第１の積分回路の積分コンデン
サの反対側に帰還され、遮断周波数に対して伝送帯域側
の成分が大きくされる。これにより、これらの積分出力
が振幅調整され、第１の積分回路の出力で、遮断周波数
領域を補償すると共に、特に遮断周波数近辺の伝送帯域
側の特性を急峻になるように補足し、かつ第２の積分回
路の出力信号で遮断領域側の成分を減少させる補償信号
が発生される。これにより、ハイパスフィルタはほぼ目
標ステップ応答特性を呈し、したがってローカットさ
れ、かつ素早く基線復帰するインパル出力が得られる。When the input impulse passes through the input high-pass filter, the components near the cut-off frequency are also excessively cut in accordance with the cut-off frequency characteristic higher than the required cut-off frequency characteristic. During this time, in the compensation signal generating circuit, the low frequency component in the cutoff region side with respect to the cutoff frequency is generated with a relatively large amplitude by the integration of the output signal of the first integration circuit in the second integration circuit. The output signal of the first integrating circuit is
Is output to the opposite side of the integration capacitor of the first integration circuit, and the component on the transmission band side with respect to the cutoff frequency is increased. As a result, the amplitudes of these integrated outputs are adjusted, and the cut-off frequency region is compensated for by the output of the first integrating circuit, and the characteristics on the transmission band side near the cut-off frequency are complemented so as to be steep. A compensation signal for reducing components in the cutoff region is generated by the output signal of the second integration circuit. As a result, the high-pass filter exhibits almost the target step response characteristic, and therefore, an impulse output that is low-cut and quickly returns to the baseline can be obtained.
【０００６】[0006]
【実施例】図１は本発明の一実施例による遮断周波数５
０Ｈｚのインパルス用ハイパスフィルタを示すもので、
一次の微分回路よりなる入力用ハイパスフィルタ１と、
第１の積分回路２と、第２の積分回路３と、その出力信
号の振幅を１／４に低減する振幅調整回路４と、入力ハ
イパスフィルタ１の出力信号と補償信号とを加算する加
算器Ａ５とから構成されている。FIG. 1 shows a cutoff frequency 5 according to an embodiment of the present invention.
It shows a high-pass filter for 0 Hz impulse,
An input high-pass filter 1 comprising a first-order differentiating circuit;
A first integration circuit 2, a second integration circuit 3, an amplitude adjustment circuit 4 for reducing the amplitude of the output signal to 1/4, and an adder for adding the output signal of the input high-pass filter 1 and the compensation signal A5.
【０００７】図２はその詳細回路を示すもので、抵抗Ｒ
１及びコンデンサＣ１は、ハイパスフィルタの必要な遮
断周波数５０Ｈｚに対して２倍の１００Ｈｚに相応する
時定数（１．６ｍｓ）のＣＲ（コンデンサ及び抵抗）一
次の微分回路よりなる入力用ハイパスフィルタ１を構成
する。Ａ１〜Ａ３は緩衝用増幅器である。抵抗Ｒ２、コ
ンデンサＣ２は第１の積分回路２、抵抗Ｒ３、コンデン
サＣ３は第２の積分回路３を構成し、積分コンデンサで
あるコンデンサＣ２の入力と反対側端子に緩衝用増幅器
Ａ２を通して第２の積分回路３の出力信号を帰還され
る。これらの第１及び第２の積分回路２、３は、所謂帰
還型のローパスフィルタを構成している。このローパス
フィルタの出力信号は遮断周波数５３Ｈｚ程度に設定さ
れ、肩特性はＱ＝（Ｃ２／２Ｃ３）1/2 ＝０．５（この
式でＣ２、Ｃ３は所属のコンデンサ容量値とする）によ
り設定されている。この際、第１の積分回路３は同じ遮
断周波数の一次のローパスフィルタ特性を呈する。緩衝
用増幅器Ａ３は第１の積分回路２の出力電圧Ｂを加算器
Ａ５に供給し、増幅器Ａ４は第２の積分回路３の出力電
圧Ｃを１／４に振幅調整して加算器Ａ５に供給する。FIG. 2 shows a detailed circuit of the circuit.
1 and the capacitor C1 are an input high-pass filter 1 composed of a CR (capacitor and resistor) first-order differentiating circuit having a time constant (1.6 ms) corresponding to 100 Hz which is twice the cut-off frequency required for the high-pass filter of 50 Hz. Constitute. A1 to A3 are buffer amplifiers. The resistor R2 and the capacitor C2 constitute a first integrating circuit 2, and the resistor R3 and the capacitor C3 constitute a second integrating circuit 3. The second integrating circuit 3 is connected to a terminal opposite to the input of the capacitor C2 as an integrating capacitor through a buffer amplifier A2. The output signal of the integration circuit 3 is fed back. These first and second integrating circuits 2 and 3 constitute a so-called feedback low-pass filter. The output signal of this low-pass filter is set to a cutoff frequency of about 53 Hz, and the shoulder characteristic is set by Q = (C2 / 2C3) 1/2 = 0.5 (where C2 and C3 are the associated capacitor capacitance values in this equation). Have been. At this time, the first integration circuit 3 exhibits a primary low-pass filter characteristic of the same cutoff frequency. The buffer amplifier A3 supplies the output voltage B of the first integration circuit 2 to the adder A5, and the amplifier A4 adjusts the output voltage C of the second integration circuit 3 to 1/4 in amplitude and supplies it to the adder A5. I do.
【０００８】第１及び第２の積分回路２、３は、図３に
示すように、先ず必要な遮断周波数５０Ｈｚの通常のス
テップ応答特性Ｄａの傾斜特性Ｄｂで始まり、かつ最大
値の１％以下の実質的に零レベルに達する時点がステッ
プ応答特性Ｄａの実質的に零レベルに達する経過時間の
半分になる目標ステップ応答特性Ｄを想定してある。そ
して、この目標ステップ応答特性に対する遮断周波数１
００Ｈｚの入力用ハイパスフィルタ１のステップ応答特
性Ａの振幅差（ハッチングで示す）に対応する補償信号
Ｅを発生させる。As shown in FIG. 3, the first and second integration circuits 2 and 3 first start with a slope characteristic Db of a normal step response characteristic Da having a required cutoff frequency of 50 Hz, and are 1% or less of the maximum value. Of the step response characteristic Da is assumed to be half of the elapsed time to reach the substantially zero level of the step response characteristic Da. The cutoff frequency 1 for the target step response characteristic
A compensation signal E corresponding to the amplitude difference (indicated by hatching) of the step response characteristic A of the input high-pass filter 1 of 00 Hz is generated.
【０００９】即ち、入力用ハイパスフィルタ１のステッ
プ応答特性Ａは、加算による補償を可能にするように目
標ステップ応答特性Ｄに対して５０Ｈｚ近辺の成分が減
少している。補償信号Ｅはこの減少成分を補足すると共
に、目標ステップ応答特性Ｄに近づける補償を行う。第
１及び第２の積分回路２、３の出力電圧は帰還量が零の
場合それぞれ点線のようになり、第２の積分回路３の出
力電圧のテイル部分の振幅は２回積分で大きくなる。実
線で示す第１の積分回路２の出力電圧Ｂはハッチング領
域の補償信号を発生すると共に、帰還により傾斜特性Ｄ
ｂよりも内側領域、即ち時定数ＣＲ（１．６ｍｓ）以内
の領域をより多めに補償する。同様に、実線の第２の積
分回路３の出力電圧Ｃは、１／４に振幅調整され、かつ
極性反転された波形Ｃｏとなり、さらに出力電圧Ｂとの
加算により補償信号Ｅとなって特にステップ応答特性Ａ
の振幅の１％近辺、即ちテイル部分を有効に補償する。That is, in the step response characteristic A of the input high-pass filter 1, a component near 50 Hz is reduced with respect to the target step response characteristic D so as to enable compensation by addition. The compensation signal E complements the reduced component and performs compensation to approach the target step response characteristic D. When the feedback amount is zero, the output voltages of the first and second integration circuits 2 and 3 become like dotted lines, respectively, and the amplitude of the tail portion of the output voltage of the second integration circuit 3 increases by the second integration. The output voltage B of the first integration circuit 2 shown by the solid line generates a compensation signal in a hatched area, and the slope characteristic D by feedback.
The region inside b, that is, the region within the time constant CR (1.6 ms) is more compensated. Similarly, the output voltage C of the second integration circuit 3 indicated by the solid line becomes a waveform Co whose amplitude is adjusted to １ ／ and whose polarity is inverted, and further becomes a compensation signal E by addition with the output voltage B, and becomes a step signal. Response characteristics A
Around 1% of the amplitude, ie, the tail portion, is effectively compensated.
【００１０】換言すれば、図５Ａに示すように、実線で
示す遮断周波数５０Ｈｚの通常の減衰特性に対して、出
力電圧Ｂで遮断周波数１００Ｈｚから５０Ｈｚの特性に
近づけると共にハッチング領域（遮断周波数５０Ｈｚに
対して伝送帯域側）を補償し、出力電圧Ｃが主にドット
領域（遮断周波数５０Ｈｚに対して減衰領域側）を６ｄ
Ｂ／ｏｃｔにより近づける補償をすることにより、点線
で示すように遮断周波数５０Ｈｚに対して肩特性の改善
されたハイパスフィルタ特性が得られる。また、遮断周
波数５０Ｈｚ近辺で定遅延特性、即ち周波数に比例した
位相回転特性がより広い範囲で得られる。In other words, as shown in FIG. 5A, the output voltage B approaches the characteristic of the cutoff frequency of 100 Hz to 50 Hz, and the hatching region (the cutoff frequency of 50 Hz). The output voltage C is mainly 6d in the dot area (attenuation area side with respect to cutoff frequency of 50 Hz).
By compensating for closer to B / oct, a high-pass filter characteristic having an improved shoulder characteristic with respect to a cutoff frequency of 50 Hz can be obtained as shown by a dotted line. Further, a constant delay characteristic near a cutoff frequency of 50 Hz, that is, a phase rotation characteristic proportional to the frequency can be obtained in a wider range.
【００１１】入力インパルスは、補償信号Ｅを加算され
る際に、遮断周波数５０Ｈｚ領域の成分が過剰に補償さ
れるのを回避されるように、ハイパスフィルタ１の通過
時に遮断周波数５０Ｈｚ領域を予めカットされ、補償時
に急峻に遮断周波数領域が補償される。インパルスの応
答特性を確認するには、通常図４Ａに示すような時間幅
１００ｍｓの三角波に対する応答で確認しており、通常
のＣＲの遮断周波数５０Ｈｚのハイパスフィルタは、図
４Ｂに示す点線の応答波形になるのに対して、本発明の
ハイパスフィルタは、実線に示すように改善される。こ
の三角波は心電図のＱＲＳ波に近似していると見なすこ
とができ、その直後に発生する微小高域成分の検出にも
有効である。When the input impulse is added with the compensation signal E, the cut-off frequency 50 Hz region is cut beforehand when passing through the high-pass filter 1 so as to prevent components in the cut-off frequency 50 Hz region from being excessively compensated. In this case, the cut-off frequency region is sharply compensated during the compensation. In order to confirm the impulse response characteristics, a response to a triangular wave having a time width of 100 ms as shown in FIG. 4A is normally confirmed. A normal high-pass filter having a cut-off frequency of 50 Hz of a CR has a response waveform indicated by a dotted line in FIG. 4B. In contrast, the high-pass filter of the present invention is improved as shown by the solid line. This triangular wave can be considered to be similar to the QRS wave of the electrocardiogram, and is also effective for detecting a minute high frequency component generated immediately thereafter.
【００１２】図７は二次のＣＲの微分回路より構成され
た入力用ハイパスフィルタを備えた場合の実施例であ
り、図示のような定数を有するコンデンサＣ１１、抵抗
Ｒ１１及びＣ１２、抵抗Ｒ１２より構成される二次の入
力用ハイパスフィルタ１１に後続する緩衝増幅器Ａ１１
に、第１及び第２の積分回路が後続している。このハイ
パスフィルタは、減衰特性の漸近線が二次の１２ｄＢ／
ｏｃｔとなり、補償すべき肩領域が遮断周波数５０Ｈｚ
に近づくのに相応して、必要な遮断周波数５０Ｈｚに対
して前述の実施例の場合の２倍から約１．７倍の遮断周
波数に設定されている。抵抗Ｒ１３、Ｒ１４、緩衝増幅
器Ａ１２及びコンデンサＣ１３で第１の積分回路を構成
し、抵抗Ｒ１５、コンデンサＣ１４で第２の積分回路を
構成している。抵抗Ｒ１６、Ｒ１７で１／２の振幅調整
回路を構成する。加算器Ａ１３−入力端子へには第２の
積分出力が、また＋入力端子には第１の積分出力が抵抗
Ｒ１３から、入力用ハイパスフィルタ１１の出力は、Ｒ
１４から入力される。FIG. 7 shows an embodiment provided with an input high-pass filter constituted by a secondary CR differentiating circuit, which comprises a capacitor C11 having constants as shown, resistors R11 and C12, and a resistor R12. Amplifier A11 following the secondary input high-pass filter 11
, Followed by first and second integrating circuits. In this high-pass filter, the asymptote of the attenuation characteristic has a quadratic 12 dB /
oct, and the shoulder area to be compensated is a cutoff frequency of 50 Hz.
Accordingly, the cut-off frequency is set to twice to about 1.7 times the required cut-off frequency of 50 Hz for the above-described embodiment. The resistors R13 and R14, the buffer amplifier A12, and the capacitor C13 form a first integrating circuit, and the resistor R15 and the capacitor C14 form a second integrating circuit. The resistors R16 and R17 form a 1/2 amplitude adjustment circuit. The second integrated output is provided to the adder A13-input terminal, the first integrated output is provided to the + input terminal from the resistor R13, and the output of the input high-pass filter 11 is provided as R
14 is input.
【００１３】このような第１及び第２の積分回路で補償
信号発生回路を構成するために、図８に示すように、目
標ステップ応答特性Ｄは、遮断周波数５０Ｈｚのステッ
プ応答特性Ｄａの３７％（１／ｅ）レベルまで最初と同
じ傾斜特性で下降し、かつ一旦マイナスに振り込んだ後
に通常の半分の経過時間で零レベルに達するように想定
してある。この目標ステップ応答特性Ｄに対する入力用
ハイパスフィルタ１１のステップ応答特性Ａの振幅差
（ハッチングで示す）に対応する補償信号Ｅを発生させ
る。In order to form a compensation signal generating circuit with such first and second integrating circuits, as shown in FIG. 8, the target step response characteristic D is 37% of the step response characteristic Da at a cutoff frequency of 50 Hz. It is assumed that it descends to the (1 / e) level with the same inclination characteristics as the first, and reaches zero level in half the elapsed time of the normal after it is once transferred to minus. A compensation signal E corresponding to an amplitude difference (indicated by hatching) of a step response characteristic A of the input high-pass filter 11 with respect to the target step response characteristic D is generated.
【００１４】即ち、図８において、第１及び第２の積分
回路２、３の出力電圧Ｂ、Ｃが、点線で示す無帰還が特
性に帰還が加えられて実線で示すように得られる。即
ち、出力電圧Ｂはステップ応答特性Ａを目標ステップ応
答特性Ｄの直線領域に近づけるように補償する。出力電
圧Ｃは相対的に外側の成分が大きく、１／２に振幅調整
され、極性反転されて波形Ｃｏとなり、出力電圧Ｂの補
償で零復帰時点が後退するのを目標ステップ応答特性Ｄ
の零復帰時点に戻すように補償する。換言すれば、図５
Ｂに示すように、実線で示す遮断周波数５０Ｈｚの通常
の減衰特性に対して、出力電圧Ｂで遮断周波数近辺の成
分の過剰にカットされた特性を遮断周波数５０Ｈｚの特
性に近づけると共にハッチング領域（遮断周波数５０Ｈ
ｚに対して伝送帯域側）を補償し、出力電圧Ｃが主にド
ットで示す減衰領域側を１２ｄＢ／ｏｃｔにより近づけ
る補償をすることにより、点線で示すように遮断周波数
５０Ｈｚに対して肩特性の改善されたハイパスフィルタ
特性が得られる。三角波に対しては、図４Ｃに示すよう
な応答波形になり、実線に示すように点線波形から改善
される。That is, in FIG. 8, the output voltages B and C of the first and second integration circuits 2 and 3 are obtained as shown by the solid line with no feedback shown by the dotted line with feedback added to the characteristics. That is, the output voltage B compensates the step response characteristic A so as to approach the linear region of the target step response characteristic D. The output voltage C has a relatively large outer component, the amplitude of which is adjusted to 、, the polarity is inverted, and the waveform Co is obtained.
Is compensated to return to the point of return to zero. In other words, FIG.
As shown in B, the characteristic of the output voltage B, which is excessively cut off in the vicinity of the cut-off frequency, approaches the characteristic of the cut-off frequency of 50 Hz, as well as the normal attenuation characteristic of the cut-off frequency of 50 Hz shown by the solid line. Frequency 50H
z in the transmission band), and compensates for the output voltage C so that the attenuation region side mainly represented by the dots becomes closer to 12 dB / oct, so that the shoulder characteristic of the cutoff frequency 50 Hz is obtained as shown by the dotted line. An improved high-pass filter characteristic is obtained. For a triangular wave, a response waveform as shown in FIG. 4C is obtained, which is improved from a dotted waveform as shown by a solid line.
【００１５】さらに、前述の一次ハイパスフィルタ及び
二次のハイパスフィルタを直列に接続することにより、
三次のハイパスフィルタを構成することがでる。この場
合、図５Ｃに示すように、減衰特性の漸近線が１８ｄＢ
／ｏｃｔの周波数特性に対して、同様に第１の積分回路
の出力電圧で特性全体及びハッチング領域を補償し、第
２の積分回路の出力電圧でドット領域を補償することに
より、点線で示す周波数特性が得られる。三角波に対し
ては、図４Ｄに示す応答波形になる。Further, by connecting the above-mentioned primary high-pass filter and secondary high-pass filter in series,
A third-order high-pass filter can be configured. In this case, as shown in FIG. 5C, the asymptote of the attenuation characteristic is 18 dB.
Similarly, for the frequency characteristic of / oct, the output voltage of the first integration circuit compensates for the entire characteristic and the hatched area, and the output voltage of the second integration circuit compensates for the dot area. Characteristics are obtained. The response waveform for the triangular wave is shown in FIG. 4D.
【００１６】尚、本発明は、ＱＲＳ波に限らず、インパ
ルスの直後に発生する高域成分を抽出する場合に適用可
能である。二次のハイパスフィルタは、前述の一次ハイ
パスフィルタを直列に接続して構成することもでき、三
次のハイパスフィルタは入力用ハイパスフィルタを三次
にして同様に相応の補償回路を付属させて構成すること
もできる。The present invention is applicable not only to the QRS wave but also to a case where a high-frequency component generated immediately after an impulse is extracted. The secondary high-pass filter can also be configured by connecting the above-mentioned primary high-pass filter in series, and the tertiary high-pass filter should be configured by tertiary input high-pass filter and also with a corresponding compensation circuit attached. Can also.
【００１７】[0017]
【発明の効果】以上、本発明の抵抗及びコンデンサを用
いた簡単なアナログ回路によるインパルス用ハイパスフ
ィルタにより、ハイパスフィルタの遮断周波数領域の位
相推移を無くして振幅の肩特性を急峻にすることが可能
となる。つまり、遮断周波数領域を主成分にするインパ
ルスに対するハイパスフィルタ通過後の基線復帰を早く
する。ＱＲＳ波の直後に発生するＬＰ等の微小高域成分
も抽出可能になる。ハイパスフィルタを二次、三次と高
次化することにより、一層急峻な低域減衰特性が実現さ
れ、インパルス応答特性が一層改善される。As described above, the impulse high-pass filter using the simple analog circuit using the resistor and the capacitor according to the present invention makes it possible to eliminate the phase transition in the cut-off frequency region of the high-pass filter and to sharpen the shoulder characteristic of the amplitude. Becomes In other words, the return of the base line after passing through the high-pass filter to the impulse whose main component is the cutoff frequency region is accelerated. A minute high-frequency component such as LP generated immediately after the QRS wave can also be extracted. By increasing the order of the high-pass filter to the second and third order, a steeper low-frequency attenuation characteristic is realized, and the impulse response characteristic is further improved.
【図１】本発明の一実施例による心電図信号用ハイパス
フィルタの基本構成を示す図である。FIG. 1 is a diagram showing a basic configuration of an electrocardiogram signal high-pass filter according to an embodiment of the present invention.
【図２】同ハイパスフィルタの詳細回路を示す図であ
る。FIG. 2 is a diagram showing a detailed circuit of the high-pass filter.
【図３】同ハイパスフィルタの動作を説明する図であ
る。FIG. 3 is a diagram illustrating the operation of the high-pass filter.
【図４】図１及び図７によるハイパスフィルタの応答特
性を説明する図である。FIG. 4 is a diagram for explaining a response characteristic of the high-pass filter according to FIGS. 1 and 7;
【図５】図１及び図７によるハイパスフィルタの周波数
特性を示す図である。FIG. 5 is a diagram showing a frequency characteristic of the high-pass filter according to FIGS. 1 and 7;
【図６】本発明によるハイパスフィルタの入力信号とな
る心電図の波形図である。FIG. 6 is a waveform diagram of an electrocardiogram which is an input signal of a high-pass filter according to the present invention.
【図７】本発明の別の実施例によるインパルス用ハイパ
スフィルタの構成を示す図である。FIG. 7 is a diagram showing a configuration of an impulse high-pass filter according to another embodiment of the present invention.
【図８】同別の実施例によるハイパスフィルタの動作を
説明する図である。FIG. 8 is a diagram illustrating the operation of a high-pass filter according to another embodiment.
１、１１ 入力用ハイパスフィルタ 1,11 High-pass filter for input
Claims (1)
波数よりも高い遮断周波数のＣＲの微分回路よりなる入
力用ハイパスフィルタと、必要な遮断周波数のステップ
応答特性の傾斜で始まり、かつ実質的に零レベルに達す
る経過時間が半分になる目標ステップ応答特性に対する
入力用ハイパスフィルタのステップ応答特性の振幅差に
対応する補償信号を発生する補償信号発生回路と、前記
入力ハイパスフィルタの出力信号と前記補償信号とを加
算する加算回路とを備え、 前記補償信号発生回路は、前記入力用ハイパスフィルタ
の出力信号を入力とする第１の積分回路と、この積分回
路の出力信号の積分を行う第２の積分回路とを有すると
共に、前記第２の積分回路の出力信号は前記第１の積分
回路の積分コンデンサの入力端子と反対側の端子に帰還
され、前記第１及び第２の積分回路の出力信号の振幅調
整及び前記第１の積分回路の出力信号から前記第２の積
分回路の出力信号の減算により前記補償信号を発生させ
ることを特徴とするインパルス用ハイパスフィルタ。1. An input high-pass filter comprising a CR differentiating circuit to which an impulse is input and having a cut-off frequency higher than a required cut-off frequency, and a slope of a step response characteristic of a necessary cut-off frequency, and substantially starts. A compensation signal generating circuit for generating a compensation signal corresponding to an amplitude difference of a step response characteristic of an input high-pass filter with respect to a target step response characteristic in which an elapsed time to reach zero level is reduced, an output signal of the input high-pass filter and the compensation A compensating signal generating circuit, wherein the compensation signal generating circuit receives the output signal of the input high-pass filter as an input, and integrates the output signal of the integrating circuit. And an output signal of the second integration circuit is connected to an input terminal of the first integration circuit opposite to an input terminal of the integration capacitor. And adjusting the amplitude of the output signals of the first and second integration circuits and subtracting the output signal of the second integration circuit from the output signal of the first integration circuit to generate the compensation signal. Characteristic high-pass filter for impulse.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04135674A JP3079330B2 (en) | 1992-04-30 | 1992-04-30 | High-pass filter for impulse |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04135674A JP3079330B2 (en) | 1992-04-30 | 1992-04-30 | High-pass filter for impulse |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05308245A JPH05308245A (en) | 1993-11-19 |
| JP3079330B2 true JP3079330B2 (en) | 2000-08-21 |
Family
ID=15157279
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04135674A Expired - Fee Related JP3079330B2 (en) | 1992-04-30 | 1992-04-30 | High-pass filter for impulse |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3079330B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USRE44115E1 (en) | 2001-12-11 | 2013-04-02 | Transpacific Plasma, Llc | Electronic messenger |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5565812A (en) * | 1995-03-23 | 1996-10-15 | Texas Instruments Incorporated | Increased sensitivity signal shaper circuit to recover a data stream coming from a digitally modulated channel |
| US5708389A (en) * | 1996-03-15 | 1998-01-13 | Lucent Technologies Inc. | Integrated circuit employing quantized feedback |
| CN106886014B (en) * | 2017-03-23 | 2023-06-30 | 桂林理工大学 | Dual receive channel for pulsed lidar |
-
1992
- 1992-04-30 JP JP04135674A patent/JP3079330B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USRE44115E1 (en) | 2001-12-11 | 2013-04-02 | Transpacific Plasma, Llc | Electronic messenger |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05308245A (en) | 1993-11-19 |
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