JP4777326B2 - Electrocardiograph with additional lead function and method for deriving additional lead electrocardiogram - Google Patents

Description

  The present invention provides an additional inductive function capable of easily and appropriately obtaining an additional electrocardiogram effective for diagnosis of ischemic heart disease or acute myocardial infarction in a myocardial region that is difficult to diagnose even by a standard 12-lead electrocardiogram. This invention relates to an electrocardiograph equipped with an additional electrocardiogram derivation method.

  When measuring an electrocardiogram of a patient, ten electrodes connected to an electrocardiograph are used, and electrodes are mounted at six locations for measurement of chest leads and at four locations for measurement of limb leads, respectively. Based on the electrocardiogram detected from these 10 electrodes by an electrocardiograph, the standard 12-lead limb 6-lead waveform (I, II, III, aVR, aVL, aVF) and the standard 12-lead chest 6 lead Waveforms (V1, V2, V3, V4, V5, V6) are calculated and output.

  In general, the relationship between the induction waveform for obtaining a standard 12-lead electrocardiogram and the electrocardiogram at the measurement site is as shown in [Table 1] below.

[Table 1]
I induction: vL-vR
II induction: vF-vR
III induction: vF-vL
aVR induction: vR- (vL + vF) / 2
aVL induction: vL- (vR + vF) / 2
aVF induction: vF- (vL + vR) / 2
V1 induction: v1- (vR + vL + vF) / 3
V2 induction: v2- (vR + vL + vF) / 3
V3 induction: v3- (vR + vL + vF) / 3
V4 induction: v4- (vR + vL + vF) / 3
V5 induction: v5- (vR + vL + vF) / 3
V6 induction: v6- (vR + vL + vF) / 3
Where v is a potential detected at the electrode mounting position.

  Diagnosing a patient's heart disease using a large number of electrodes in this manner can be performed in a state where the patient is resting, such as in a hospital equipped with facilities.

  However, for example, when performing home medical care or emergency medical care, it is often impossible to use a large number of electrodes and attach each electrode to an appropriate position on the surface of the living body when viewed from the patient's state. . Furthermore, it may be difficult to transmit a multi-channel signal to obtain a large number of induced waveforms. In such a case, it is generally possible to transmit an electrocardiogram signal on the order of one channel (one lead), and at most several leads of a standard 12 lead waveform using 2 to 4 electrodes. Diagnosis for heart disease is made by measuring the waveform.

  From this point of view, the present inventor can properly diagnose and treat various heart diseases by using a subset of a minimum number of induction systems for obtaining a conventionally known standard 12-lead ECG. A standard 12-lead ECG construction method and an electrocardiogram inspection apparatus for reconstructing a standard 12-lead ECG that can be developed were developed and a patent application was filed (see Patent Document 1).

  That is, in the construction method of the standard 12-lead ECG described in Patent Document 1 described above, as the subsets of the lead system having the minimum number of channels, the limb lead I and II leads when obtaining the standard 12-lead ECG Two inductions of chest induction are used, V1 induction and V5 or V6 induction. By these inductions, the third induction and the aV induction (aVR induction, aVL induction, aVF induction) are obtained by calculation based on the unique relationship of each induction shown in Table 1. Further, the remaining leads of the chest lead, that is, lead V2, lead 3, lead V4, lead V6 or lead V5 are obtained by calculation from the relationship between the potential, the lead vector, and the heart vector.

  Since the standard 12-lead ECG obtained in this way uses a subset of the conventional standard 12-lead ECG system, it is possible to easily and reliably position each electrode at the time of mounting each electrode. Yes, the work does not require much skill. In addition, a highly accurate standard 12-lead electrocardiogram can be reconstructed, and diagnosis and treatment for various heart diseases can be performed appropriately.

However, the standard 12-lead electrocardiogram is not only obtained from the limb 6 lead and the chest 6 lead using 10 electrodes as in the past, but also by the method described in Patent Document 1 described above, a highly accurate standard Even when a 12-lead ECG is obtained, for example, in the case of myocardial infarction, when the coronary artery that sends blood to the myocardium is blocked on the anterior wall, side wall, or lower wall of the myocardium, an abnormality in the ECG waveform is confirmed and diagnosed. It is relatively easy to do. However, when the occlusion of the coronary artery occurs in the posterior wall of the myocardium, the electrode mounting site is far from the posterior wall, so the sensitivity of the electrocardiogram waveform is low and the influence on the electrocardiogram waveform due to the occlusion of the coronary artery is difficult to reflect. Further, since the electrode mounting position of the standard 12-lead electrocardiogram is almost on the left side of the body surface, the sensitivity to the right myocardium is low. Therefore, in diagnosis, there is a high possibility of missing the occlusion of the coronary artery on the posterior wall, the right wall, or the right lower wall.
JP 2002-34943 A

  Therefore, conventionally, in order to properly diagnose the above-mentioned myocardial infarction at the rear wall, pulmonary heart, pulmonary embolism, right ventricular infarction, right ventricular hypertrophy, right chest heart, other right ventricular load diseases, etc. In addition, V7, V8, and V9 leads measured at the electrode placement site on the extension line of the chest lead, and V3R, V4R, V5R, and V6R lead by the electrode site that is symmetrical to the electrode site of the chest lead Obtaining an electrocardiogram has been performed. However, the electrode mounting position for obtaining additional electrocardiograms of V7, V8, and V9 leads is the patient's back and the like. In order to keep the patient resting, it is necessary to lie down on the back, but in order to put the electrode on the patient's back etc., the patient may be forced to take an unreasonable posture, and it is said that wearing the electrode is complicated There is also a problem. In addition, V7, V8, V9 leads and V3R, V4R, V5R, V6R lead additional electrocardiograms cannot be measured with a normal standard 12 lead electrocardiograph. A dedicated electrocardiograph with an electrocardiogram measurement function is required.

  An object of the present invention is to solve the problems of the prior art and to easily obtain additional guidance without additionally mounting an electrode to the electrode used in 12 guidance. Another object of the present invention is to easily obtain an additional lead from a part of the lead of the 12-lead electrocardiogram without attaching an additional lead electrode.

  In order to solve the above-described problem, an electrocardiograph according to the present invention includes a potential detector that measures at least any two evoked potentials of limb leads and at least any two evoked potentials of chest leads, and the potential. An additional induction potential calculating means for calculating an additional induction potential based on the induction potential measured by the detector, wherein the additional induction potential calculation means uses the transfer coefficient α representing the relationship between inductions, and An additional induction function is provided, wherein the additional induction potential is calculated based on the induction potential measured by a potential detector.

In the electrocardiograph of the present invention, it is preferable that the transmission coefficient α satisfies V _i = Σα _{i, j} V _j (where i is an induction number for additional induction and j is an induction number for 12 leads).

  Further, the additional lead electrocardiogram derivation method according to the present invention is based on the measured limb lead at least any two lead potentials and the chest lead lead at least any two lead potentials. Is used to calculate the additional induced potential.

In the additional lead electrocardiogram derivation method of the present invention, it is preferable that the transmission coefficient α satisfies V _i = Σα _{i, j} V _j (where i is the lead number of the lead and j is the lead number of 12 leads). .

Further, in addition lead ECG derivation method of the present invention, the additional induction potential, V7 to V9 _{induction, V 3R, V 4R, V} 5R, preferably contains one inductive least one of _{V 6R} induction.

  An electrocardiograph according to the present invention comprises an electrode attached to the body surface of a living body to obtain a standard 12 electrocardiogram waveform, a potential detector for measuring a standard 12-lead electrocardiogram signal from each of the electrodes, An electrocardiogram signal memory for storing the electrocardiogram signals of the standard 12-lead electrocardiogram measured by the potential detector, and a waveform of the standard 12-lead electrocardiogram by inputting an electrocardiogram signal obtained via the electrocardiogram signal memory. A standard 12-lead ECG waveform means for processing and an ECG signal obtained via the ECG signal memory are inputted, and an ECG signal of the additional lead ECG is calculated based on a calculation parameter α set in advance. Additional-lead ECG signal calculating means, additional-lead ECG waveform output means for inputting the ECG signal calculated by the additional-lead ECG signal calculating means and performing waveform processing of the additional-lead ECG, and the standard 2 lead ECG waveform output means and said additional lead ECG waveform output device and the electrocardiogram waveform output which is output from and a display monitor for simultaneously screen display, respectively.

Further, the electrocardiograph of the present invention, the signal potential of the additional lead ECG, V7 to V9 _{induction, V 3R, V 4R, V} 5R, preferably contains one inductive least one of _{V 6R} induction.

  According to the present invention, it is possible to easily obtain additional guidance without additionally attaching an electrode to the electrode used in 12 guidance.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
The first embodiment uses, for example, an electrocardiogram signal measured at the electrode attachment site of the standard 12-lead ECG by the potential detector of the standard 12-lead electrocardiograph, for example, V7 at the electrode attachment site on the extension line of the chest lead. , V8, V9 induction and V _3R , V _4R , V _5R induction, and a method and apparatus for calculating additional induction by calculation.

That is, the first embodiment calculates the cardiac potential (electrocardiogram) at the additional lead site from the electrocardiographic signal obtained by the potential detector of the 12-lead electrocardiograph. The additional leads V7, V8, V9 and _V3R , _V4R , _V5R are calculated from the obtained eight electrocardiogram signals (I, II, V1, V2, V3, V4, V5, V6).

但し、Ｖは電位マトリックス、Ｈは心臓ベクトル、Ｌは誘導ベクトルをそれぞれ示す。 (Principle of the derivation method of additional electrocardiogram using the lead vector)
In the clinical electrocardiogram, the cardiac power supply at an arbitrary time can be expressed by a fixed single dipole according to induction theory, and the potential (V) at an arbitrary induction location is expressed by the following equation (1-1) to (1-3).
V = L · H (1-1)

Here, V represents a potential matrix, H represents a heart vector, and L represents an induction vector.

  However, the heart vector H changes with the electrical activity of the heart, and the inner product of the heart vector H and the induction vector L is a cardiac potential (electrocardiogram) V measured by an electrocardiograph. Further, since the induction vector L has an eigenvalue for a specific person, the cardiac potential can be determined by the space electromotive force space vector. That is, the arbitrarily induced cardiac potential is determined by three parameters.

Therefore, in the standard 12-lead electrocardiograph potential detector, since 8 electrocardiogram signals are measured, it is possible to calculate the electrocardiogram potential at any part of the body surface of the living body using these electrocardiogram signals. It is. For example, from the electrocardiogram signals (I, II, V1, V2, V3, V4, V5, V6) measured by a standard 12-lead electrocardiograph, additional leads V7, V8, V9, V _3R , V _4R, the case of calculating the _{V 5R,} can be expressed by the following equation (1-4).

However, i is the induction number of additional induction (V7, V8, V9, _V3R , _V4R , _V5R ), j is the induction number of standard 12 induction (I, II, V1, V2, V3, V4, V5, V6) ). Α is a transfer coefficient representing the relationship between inductions.

Therefore, the parameter α in the equation represented by the equation (1-4) is a constant theoretically determined by the individual body structure, but is an unknown number in the equation (1-4). Therefore, the standard 12 lead I, II, V1, V2, V3, V4, V5, V6 lead and the additional lead V7, V8, V9, _V3R , _V4R , _V5R lead were actually measured, It is possible to obtain the parameter α as a solution of the least square method by substituting in (1-5).
A = (V ^T _j V _j ) ⁻¹ V ^T _j V _i (1-5)
Where A = {α _{i, j} }
V _j = {V _{s, j} }
V _i = {V _{i, s} }
T indicates vector transposition and s indicates a data sample.

In this way, by obtaining the parameter α, based on the expression (1-4), from the electrocardiogram signal for deriving the standard 12-lead ECG, the additional leads V7, V8, V9 and V _3R , V _4R and _V5R induction can be easily obtained.

  Therefore, the electrocardiogram signal of the additional lead electrocardiogram other than the standard 12-lead electrocardiogram can be easily derived by calculation based on the electrocardiogram signal of the standard 12-lead electrocardiogram measured by the potential detector.

(Configuration of an electrocardiograph equipped with a function for deriving an additional electrocardiogram)
FIG. 1 is a system configuration diagram of an electrocardiograph having an additional induction function for deriving an electrocardiogram signal of an additional electrocardiogram from an electrocardiogram signal of a standard 12-lead electrocardiogram according to the first embodiment. That is, in FIG. 1, reference numeral 10 indicates a potential detector for detecting an electrocardiographic signal of a standard 12-lead electrocardiogram. This potential detector 10 is measured from electrodes (RA, LA, RL, LL, V1, V2, V3, V4, V5, V6) attached to the body surface of the living body to obtain a standard 12-lead ECG waveform. Functions as a biological amplifier and an A / D converter for measuring the electrocardiogram signals (I, II, V1, V2, V3, V4, V5, V6).

  Each standard 12-lead ECG signal (I, II, V1, V2, V3, V4, V5, V6) detected by the potential detector 10 is stored in the ECG signal memory 12 and is also a standard 12-lead ECG. Input to the waveform output means 14. The electrocardiogram signals (I, II, V1, V2, V3, V4, V5, V6) stored in the electrocardiogram signal memory 12 are input to the additional lead electrocardiogram calculation means 16. The additional lead electrocardiogram calculation means 16 is based on the input electrocardiogram signals (I, II, V1, V2, V3, V4, V5, V6) and a calculation parameter α set in advance in the memory 15 to be described later. Then, the electrocardiogram signals (V7, V8, V9) of the additional lead electrocardiogram are calculated and output to the additional lead electrocardiogram waveform output means 18.

  Then, the ECG waveform outputs output from the standard 12-lead ECG waveform output means 14 and the additional-lead ECG waveform output means 18 are respectively input to the display monitor 20. Then, the display monitor 20 displays the standard 12-lead ECG and the additional lead ECG simultaneously.

Here, an average model value obtained from a population may be used as the calculation parameter α. That is, by the potential detector 10, each induction potential of standard 12 leads (I, II, V1, V2, V3, V4, V5, V6) and additional induction potentials (V7, V8, V9, V _3R , ECG signals consisting of V _4R , V _5R ) are collected from a group of a plurality of patients or healthy persons, and a database is constructed in the additional lead electrocardiogram calculation means 16. Then, the additional electrocardiogram calculating means 16 calculates the average model calculation parameter α from the data in the database, and stores the α in the memory 15. The calculation parameter α can be calculated by the above-described equation (1-5).

  The system operation of the electrocardiograph having the additional guidance function configured as described above will be described with reference to the flowchart shown in FIG.

That is, in the electrocardiograph having the additional induction function in the first embodiment, first, the electrocardiogram signals (I, II, V1, V2, V3, V4) of the patient's standard 12-lead electrocardiogram are detected by the potential detector 10. , V5, V6) are measured (STEP-101). The measured ECG signal of the standard 12-lead ECG is stored in the ECG signal memory 12 (STEP-102). Next, the calculation parameter α preset in the memory 15 is input to the additional lead electrocardiogram calculation means 16 (STEP-103). Then, the additional lead ECG calculating means 16, based on the electrocardiographic signal of the patient stored in the electrocardiographic signal memory 12 and the operation parameter alpha, the additional lead electrocardiogram electrocardiographic signal (V7, V8, V9, V 3R , V _4R , V _5R ) are calculated by calculation (STEP-104). The operation of the electrocardiogram signals (V7, V8, V9, V _3R , V _4R , V _5R ) of the additional electrocardiogram by the additional electrocardiogram calculating means 16 is based on the above-described formula (1-4) ( It can be calculated as 1-6) to (1-11).

V7 _{induction: V 7 = α 7I V I} + α 7II V II + α 7V1 V V1 + α 7V2 V V2 + ... + α 7V6 V V6 ... (1-6)
V8 _{induction: V 8 = α 8I V I} + α 8II V II + α 8V1 V V1 + α 8V2 V V2 + ... + α 8V6 V V6 ... (1-7)
V9 induction: V ₉ = α _9I V _I + α _9II V _II + α _9V1 V _V1 + α _9V2 V _V2 + ... + α _9V6 V _V6 (1-8)
V _3R induction: V _3R = α _3RI V _I + α _3RII V _II + α _3RV1 V _V1 + α _3RV2 V _V2 + ... + α _3RV6 V _V6 (1-9)
V _{4R induction: V 4R = α 4RI V I} + α 4RII V II + α 4RV1 V V1 + α 4RV2 V V2 + ... + α 4RV6 V V6 ... (1-10)
V _{5R induction: V 5R = α 5RI V I} + α 5RII V II + α 5RV1 V V1 + α 5RV2 V V2 + ... + α 5RV6 V V6 ... (1-11)

The ECG signals (V7, V8, V9, _V3R , _V4R , _V5R ) of the additional electrocardiogram thus calculated are subjected to waveform processing (STEP-105) by the additional electrocardiogram waveform output means 18. In addition, the standard 12-lead ECG signals (I, II, V1, V2, V3, V4, V5, V6) stored in the ECG signal memory 12 are processed by the standard 12-lead ECG waveform output means 14. (STEP-106) and input to the display monitor 20, respectively. The display monitor 20 simultaneously displays the input standard 12-lead ECG and additional lead ECG on the display screen (STEP-107).

An additional electrocardiogram including V7, V8, and V9 leads calculated from an electrocardiogram signal of a standard 12-lead electrocardiogram based on the first embodiment, and an additional lead electrocardiogram based on measured values of the respective V7, V8, and V9 leads. The comparison results are as shown in FIGS. Here, FIG. 3 shows a V7 lead electrocardiogram, FIG. 4 shows a V8 lead electrocardiogram, and FIG. 5 shows a V9 lead electrocardiogram. The electrocardiogram (characteristic waveform A) based on the respective calculation results approximates the electrocardiogram (characteristic waveform B) based on the actually measured values, and it is confirmed that the accuracy is extremely good. By the way, according to the electrocardiogram adopted from patients or healthy subjects in clinical practice and the statistics of 54 cases, the correlation between the electrocardiogram based on the calculation result and the electrocardiogram based on the actually measured value is about 0.83 (83%) as a whole. In addition, the allowable rate of setting the potential difference at the center point of the ST wave to 0.1 mV was about 73%. In addition, similarly for the V _3R , V _4R , and V _{5R leads} , an additional lead electrocardiogram waveform showing a high correlation with the actual measurement is obtained.

  As described above, according to the method and apparatus for deriving the additional lead electrocardiogram in the first embodiment, the electrocardiogram signal of the standard 12 lead electrocardiogram measured by the potential detector can be used for the additional lead electrocardiogram other than the standard 12 lead electrocardiogram. An electrocardiogram signal can be easily derived by calculation. In particular, it is useful for improving the diagnosis accuracy of myocardial infarction for the myocardium of the rear wall, right wall, and lower wall. In addition, according to such a derivation method, the functions of an electrocardiogram monitor and a Holter electrocardiograph can be easily expanded. For example, not only myocardial infarction in the rear wall, right wall, and lower wall, but also pulmonary heart Diagnostic accuracy for pulmonary embolism, right ventricular infarction, right ventricular hypertrophy, right chest heart, and other right ventricular load diseases can be improved. Also, these electrocardiographs can be manufactured at a low cost.

  Although the first embodiment has been described above, the derivation of the additional lead electrocardiogram according to the present invention is symmetrical with the electrode parts for V7, V8, and V9 leads and the chest lead by the electrode parts mounted on the extension line of the chest lead. It is not limited to the derivation of the additional lead electrocardiogram of V3R, V4R, V5R, V6R lead in the electrode part in position. The present invention can also be applied to the derivation of other additional lead electrocardiograms. In addition, many design changes can be made without departing from the spirit of the present invention.

[Second Embodiment]
Next, a second embodiment will be described. This second embodiment is different from the first embodiment, without using the transmission coefficient alpha, the additional lead ECG by using an induced vector _{(V7, V8, V9, V} 3R, V 4R, V 5R The point is to derive (guidance).

但し、Ｖは電位、Ｈは心臓ベクトル、Ｌは誘導ベクトルをそれぞれ示す。 (Principle of the derivation method of additional electrocardiogram using the lead vector)
The principle of the method for deriving the additional lead electrocardiogram according to the second embodiment is as follows. As described above, in the clinical electrocardiogram, the cardiac power supply at an arbitrary time can be expressed by a fixed single dipole according to induction theory, and the potential (V) at an arbitrary induction location is expressed by the following formula ( (2-1) to (2-3).
V = L · H (2-1)

Here, V represents a potential, H represents a heart vector, and L represents a guidance vector.

但し、Ｔはベクトルの転置を示す。 Therefore, when the induced potential of the measured standard 12-lead ECG is applied to the equation (2-1), the following equation (2-4) is obtained.

However, T shows transposition of a vector.

Expression (2-4) represents the general expression L · H = V. When the heart vector H is obtained from the expression (2-4), the following expression (2-5) is obtained.
H = (L ^T L) ⁻¹ L ^T V (2-5)

Based on the above equation (2-5), the additional induction potential V can be obtained by the following equation (2-6).

(Configuration of an electrocardiograph equipped with a function for deriving an additional electrocardiogram)
FIG. 6 is a system configuration diagram of an electrocardiograph for deriving an electrocardiogram signal of an additional lead electrocardiogram from an electrocardiogram signal of a standard 12-lead electrocardiogram according to the second embodiment. The electrocardiograph in the second embodiment is different from the electrocardiograph in the first embodiment in the operation process of the additional lead electrocardiogram in the additional lead electrocardiogram calculation means 17. That is, when the electrocardiogram signals (I, II, V1, V2, V3, V4, V5, V6) are input from the electrocardiogram signal memory 12, the additional lead electrocardiogram calculation means 17 is stored in the lead vector storage means 13. The lead vectors of I, II, V1, V2, V3, V4, V5, and V6, which are the measurement leads, are read out, and the heart vector H is obtained based on the equations (2-4) and (2-5). Further, the additional lead electrocardiogram calculation means 17 reads the lead induction vector L from the lead vector storage means 13 and, based on the formula (2-6), the additional lead electrocardiograms (V7, V8, V9, V _3R , V _4R). , V _5R ).

Next, the operation of the electrocardiograph shown in FIG. 6 will be described with reference to the flowchart of the electrocardiograph shown in FIG. First, the electrocardiogram signals (I, II, V1, V2, V3, V4, V5, V6) of the patient's standard 12-lead electrocardiogram are measured by the potential detector 10 (STEP-201). The measured ECG signal of the standard 12-lead ECG is stored in the ECG signal memory 12 (STEP-202). Then, the electrocardiogram signals (I, II, V1, V2, V3, V4, V5, V6) stored in the electrocardiogram signal memory 12 are input to the additional lead electrocardiogram calculation means 17. Further, from the guide vector storage means 13, the lead vectors of measurement leads I, II, V1, V2, V3, V4, V5, and V6 are read by the additional lead electrocardiogram calculation means 17, and the additional lead electrocardiogram calculation means. 17 (STEP-203). Then, the additional lead electrocardiogram calculation means 17 uses the lead vectors I, II, V1, V2, V3, V4, V5, and V6, and based on the equations (2-4) and (2-5), the heart vector H (STEP-204). Further, the additional guide vector (L ₇ ^T , L ₈ ^T , L ₉ ^T , L _3R ^T , L _4R ^T , L _5R ^T ) is input from the guide vector storage means 13 to the additional lead electrocardiogram calculation means 17 ( (STEP-205). Sonouede, additional lead ECG calculating means 17, based on the equation (2-6), additional lead electrocardiogram from the induction vector of the additional induction and heart vector _{H (V7, V8, V9,} V 3R, V 4R, V 5R) and Calculate (STEP-206).

The ECG signals (V7, V8, V9, _V3R , _V4R , _V5R ) of the additional lead ECG calculated in this way are output to the additional lead ECG waveform output means 18, and the additional lead ECG waveform output means. 18 is subjected to waveform processing and input to the display monitor 20 (STEP-207). The electrocardiogram signals (I, II, V1, V2, V3, V4, V5, V6) of the standard 12-lead ECG stored in the electrocardiogram signal memory 12 are output to the standard 12-lead ECG waveform output means 14, Waveform processing is performed by the standard 12-lead electrocardiogram waveform output means 14 and each is input to the display monitor 20 (STEP-208). The display monitor 20 simultaneously displays the input standard 12-lead ECG and additional lead ECG on the display screen (STEP-209).

  As described above, according to the method and apparatus for deriving the additional lead electrocardiogram in the second embodiment, similarly to the first embodiment, the electrocardiogram signal of the standard 12 lead electrocardiogram measured by the potential detector is used. An electrocardiogram signal of an additional electrocardiogram other than the standard 12-lead electrocardiogram can be easily derived by calculation. In particular, it is useful for improving the diagnosis accuracy of myocardial infarction for the myocardium of the rear wall, right wall, and lower wall. In addition, according to such a derivation method, the functions of an electrocardiogram monitor and a Holter electrocardiograph can be easily expanded. For example, not only myocardial infarction in the rear wall, right wall, and lower wall, but also pulmonary heart Diagnostic accuracy for pulmonary embolism, right ventricular infarction, right ventricular hypertrophy, right chest heart, and other right ventricular load diseases can be improved. Also, these electrocardiographs can be manufactured at a low cost.

[Third Embodiment]
In the case of obtaining a standard 12-lead electrocardiogram from the invention described in Patent Document 1 proposed by the present inventor as a subset of a lead system comprising a minimum number of channels by using, for example, a potential detector comprising six electrodes. Using induction I and II induction and two inductions of chest induction, V2 induction and V4 induction, (1) Induction of III and aV induction (aVR induction, aVL induction, aVF induction) It is calculated | required by calculation based on the specific relationship of each induction | guidance | derivation shown in Table 1. Further, (2) V1, V3, V5, and V6 leads, which are the remaining leads of the chest lead, are obtained by calculation from the relationship of potential [V], lead vector [L], and heart vector [H].

Therefore, in the third embodiment, a standard 12-lead electrocardiogram is obtained by using standard lead potentials (I, II, V2, and V4 electrocardiogram signals) of a standard 12-lead electrocardiogram measured by a potential detector composed of 10 or less electrodes. additional induction potential of additional lead ECG except calculated by computation (V7, V8, V9 and _{V 3R, V 4R,} electrocardiographic signals _{V 5R).}

  In this case, in order to detect ECG signals of lead I and II as standard lead potentials of the standard 12 lead ECG, left and right arms (electrodes LA and RA) and left and right lower limbs (electrodes LL and RL) in the case of limb lead Attach electrodes to the four locations. In the case of an exercise load test or the like, the four-limb lead is used as a modified 12-lead of Mason-Likar which corrects the standard 12-lead, the left and right clavicle distal ends as the left and right upper limbs, and the left and right sides as the left and right lower limbs. Electrodes are mounted at four locations on the abdomen. The electrode RL is a ground electrode. Furthermore, in order to measure the electrocardiogram signals of two leads (V2, V4) of the chest lead as the standard lead potential, for example, the fourth intercostal sternum left edge position (to obtain the electrocardiogram signal of V2) and the left clavicle Electrodes are mounted at two positions of intersections of the line and the horizontal line crossing the fifth rib (to obtain an electrocardiographic signal of V4). In this way, by a subset (part) of the standard 12-lead ECG guidance system, other standard 12-lead ECG lead potentials (electrocardiogram signals) are based on the inherent relationships of the respective leads shown in Table 1 above. Alternatively, it can be obtained by calculation based on the relationship between the potential vector, the induction vector, and the heart vector. Also, when measured with a subset of modified 12 leads, a modified 12 lead electrocardiogram and its additional lead ECG can be obtained in the same manner. Hereinafter, an embodiment of an electrocardiograph having a method for deriving an additional lead electrocardiogram and an additional lead function will be described in detail.

但し、Ｖは電位、Ｈは心臓ベクトル、Ｌは誘導ベクトルをそれぞれ示す。 (Principle of the derivation method of additional electrocardiogram using the lead vector)
The principle of the method for deriving the additional lead electrocardiogram according to the third embodiment is as follows. As described above, in the clinical electrocardiogram, the cardiac power supply at an arbitrary time can be expressed by a fixed single dipole according to induction theory, and the potential (V) at an arbitrary induction location is expressed by the following formula ( 3-1) to (3-3).
V = L · H (3-1)

Here, V represents a potential, H represents a heart vector, and L represents a guidance vector.

  Since the heart vector H is a spatial vector with a fixed position, it has only three independent parameters. Therefore, it is possible to solve the parameters of the heart vector H from three leads having spatial information. However, once the heart vector H is known, the potentials for the remaining 12 leads can also be obtained by calculation.

但し、Ｔはベクトルの転置を示す。 For example, as a standard induction potential of a standard 12-lead electrocardiogram, an electrocardiogram signal at an induction site (I, II, V2, V4) is measured, and additional induction (V7, V8, V9, _V3R , _V4R , _V5R ) In order to derive the induced potential, it is possible to perform arithmetic processing as in the following equation (3-4).

However, T shows transposition of a vector.

Formula (3-4) represents the general formula L · H = V. Accordingly, when the heart vector H is obtained from this equation (3-4), the following equation (3-5) is obtained.
H = (L ^T L) ⁻¹ L ^T V (3-5)

Based on the above equation (3-5), the additional induction potential V can be obtained by the following equation (3-6).

[Configuration of an electrocardiograph equipped with a function for deriving an additional electrocardiogram]
FIG. 8 is a system configuration diagram of an electrocardiograph having a function of deriving an additional lead electrocardiogram according to the third embodiment. That is, in FIG. 8, reference numeral 10 </ b> A indicates a potential detector for measuring an electrocardiogram signal as a standard induction potential of a standard 12-lead electrocardiogram. This potential detector 10A has 10 or less electrodes mounted on the body surface of a living body for obtaining a standard induced potential of a standard 12-lead electrocardiogram, that is, a subset of standard 12-lead ECG potential detectors (for example, RA, LA, 6) (RL, LL, V2, and V4) and functions as a biological amplifier and an A / D converter for measuring electrocardiogram signals (I, II, V2, and V4).

The electrocardiogram signals (I, II, V2, V4) of the standard 12 lead potential detected by the potential detector 10A are stored in the electrocardiogram signal memory 12A and input to the standard 12 lead electrocardiogram calculation means 14A. The The electrocardiogram signals (I, II, V2, V4) stored in the electrocardiogram signal memory 12A are input to the additional lead electrocardiogram calculation means 17A. Then, the additional lead electrocardiogram calculation means 17A reads out the lead vectors of I, II, V2, and V4, which are measurement leads, stored in the lead vector storage means 13A, and the formulas (3-4) and (3-5) are read. Based on this, the heart vector [H] is obtained. Furthermore, additional lead ECG calculating unit 17A is stored in the lead vector storage unit 13A inductive added vector _{^{[L] (L 7 T,}} L 8 T, L 9 T, L 3R T, L 4R T, L 5R T) And the electrocardiographic signals (V7, V8, V9, V _3R , V _4R , V _5R ) as the additional induction potentials of the additional electrocardiogram are calculated based on the equation (3-6).

  Thus, the electrocardiogram signal as the additional induction potential calculated by the additional lead electrocardiogram calculation means 17A is input to the additional lead electrocardiogram waveform output means 18A. The electrocardiogram signal as the standard 12-lead potential calculated by the standard 12-lead electrocardiogram calculation means 14A is input to the standard 12-lead electrocardiogram waveform output means 20A.

  Then, the ECG waveform outputs output from the standard 12-lead ECG waveform output means 20A and the additional-lead ECG waveform output means 18A are respectively input to the display monitor 22A, and the standard 12-lead ECG and the additional-lead ECG are simultaneously imaged. Configured to display.

  The system operation of the electrocardiograph having the additional guidance function configured as described above will be described with reference to the flowchart shown in FIG.

  First, in an electrocardiograph having an additional induction function, an electrocardiogram signal (I, II, V2, V4) as a standard induction potential of a patient's standard 12-lead electrocardiogram is measured by the potential detector 10A (STEP- 301). The electrocardiogram signals (I, II, V2, V4) of the measured standard induction potential are stored in the electrocardiogram signal memory 12A (STEP-302).

Further, from the guide vector storage means 13A, the lead vectors of measurement leads I, II, V2 and V4 are read out by the additional lead electrocardiogram calculation means 17A and input to the additional lead electrocardiogram calculation means 17A (STEP- 303). Further, the additional lead electrocardiogram calculation means 17A uses these lead vectors I, II, V2, and V4, and based on the patient's electrocardiogram signals (I, II, V2, V4) stored in the electrocardiogram signal memory 12A. Thus, the heart vector [H] is calculated from the equations (3-4) and (3-5) indicating the relationship between the potential [V], the induction vector [L], and the heart vector [H] related to induction (STEP- 304). Further, the induction vector (L ₇ ^T , L ₈ ^T , L ₉ ^T , L _3R ^T , L _4R ^T , L _5R ^T ) is input from the induction vector storage means 13A to the additional induction electrocardiogram calculation means 17A ( (STEP-305). In addition, the additional lead electrocardiogram calculation means 17A calculates the electrocardiogram signals (V7, V8, V9, V _3R , V _{3) of} the additional lead electrocardiogram from the heart vector [H] and the lead induction vector based on the equation (3-6). _4R , _V5R ) are calculated (STEP-306).

On the other hand, the electrocardiogram signals (I, II, V2, V4) of the standard induction potential stored in the electrocardiogram signal memory 12A are input to the standard 12-lead electrocardiogram calculation means 14A, and the induction potential (I of the standard 12-lead electrocardiogram) II, III, V1, V2, V3, V4, V5, V6, aVR, aVL, aVF). Here, the leads V1, V3, V5, and V6 are based on the relationship between the potential vector, the lead vector, and the heart vector, and the heart vector [H] obtained in STEP-304 and the lead vector (L ₁ ^T , L _{3 ^T, L} ^{5 T,} is calculated using _L ^{6 T)} and. The induced potential of the standard 12-lead ECG calculated by the standard 12-lead ECG calculating means 14A is processed by the standard 12-lead ECG waveform output means 20A and input to the display monitor 22A (STEP-307).

The electrocardiogram signals (V7, V8, V9, V _3R , V _4R , V _5R ) as additional induction potentials of the additional lead electrocardiogram calculated by the additional lead electrocardiogram calculation means 17A are sent by the additional lead electrocardiogram waveform output means 18A. The waveform is processed and input to the display monitor 22A (STEP-308). Further, the waveform-added additional lead ECG waveform output and the standard 12 lead ECG waveform output are simultaneously displayed on the display screen of the display monitor 22A (STEP-309).

但し、Ｖは電位マトリックス、Ｈは心臓ベクトル、Ｌは誘導ベクトルをそれぞれ示す。 [Fourth Embodiment]
[Derivation method of additional electrocardiogram using the relationship (transmission coefficient α) between leads]
Guiding theories based on the dipole model of the heart are the theories most used today for clinical applications. The potential (V) at an arbitrary induction location can be obtained by the following equations (4-1) to (4-3).
V = L · H (4-1)

Here, V represents a potential matrix, H represents a heart vector, and L represents an induction vector.

〔但し、ｉは付加誘導部位の誘導番号（Ｖ７、Ｖ８、Ｖ９、Ｖ_３Ｒ、Ｖ_４Ｒ、Ｖ_５Ｒ）、ｊは標準１２誘導の標準誘導電位の誘導番号（Ｉ、II、Ｖ２、Ｖ４）を示している。αは誘導間の関係を表わす伝達係数である。〕。なお、理論的に伝達係数αは、個人の胴体構造で決められた定数であるが、上記式（４−４）においては未知数である。しかし、予め各誘導部位の誘導電位（Ｖ７、Ｖ８、Ｖ９、Ｖ_３Ｒ、Ｖ_４Ｒ、Ｖ_５ＲとＩ、II、Ｖ２、Ｖ４）を実測して、上記式（４−４）から次式（４−５）に示すように、伝達係数αを逆に求めることも可能である。
Ａ ＝ （Ｖ^Ｔ _ｊＶ_ｊ）^―１Ｖ^Ｔ _ｊＶ_ｉ …（４−５）
但し、Ａ ＝ ｛α_ｉ，ｊ｝
Ｖ_ｊ ＝ ｛Ｖ_ｓ，ｊ｝
Ｖ_ｉ ＝ ｛Ｖ_ｉ，ｓ｝
ｉは付加誘導部位の誘導番号（Ｖ７、Ｖ８、Ｖ９、Ｖ_３Ｒ、Ｖ_４Ｒ、Ｖ_５Ｒ）、ｊは標準１２誘導の標準誘導電位の誘導番号（Ｉ、II、Ｖ２、Ｖ４）を示し、ｓはデータサンプルを示す。 As described above, according to this induction theory, the cardiac potential at any induction site is determined by three parameters. Accordingly, the electrocardiographic potentials at arbitrary sites on three or more body surfaces are correlated with each other. That is, some of the induced potentials can be expressed by a linear combination of other induced potentials. For example, the relationship shown in the following formula (4-4) is obtained.

[Where i is the induction number of the additional induction site (V7, V8, V9, V _3R , V _4R , V _5R ), j is the induction number of the standard induction potential of standard 12 induction (I, II, V2, V4) Show. α is a transfer coefficient representing the relationship between inductions. ]. Theoretically, the transfer coefficient α is a constant determined by the body structure of the individual, but is unknown in the above equation (4-4). However, the induction potentials (V7, V8, V9, _V3R , _V4R , _V5R and I, II, V2, V4) of each induction site are measured in advance, and the following equation (4) is obtained from the above equation (4-4). As shown in -5), the transmission coefficient α can be obtained in reverse.
A = (V ^T _j V _j ) ⁻¹ V ^T _j V _i (4-5)
Where A = {α _{i, j} }
V _j = {V _{s, j} }
V _i = {V _{i, s} }
i represents the induction number of the additional induction site (V7, V8, V9, _V3R , _V4R , _V5R ), j represents the induction number of the standard induction potential of standard 12 induction (I, II, V2, V4), and s Indicates a data sample.

Thus, once the transfer coefficient α is obtained, the additional induction is immediately obtained from the electrocardiogram signals (I, II, V2, V4) as the standard induction potential of the standard 12-lead electrocardiogram by the above formula (4-5). Additional induced potentials (V7, V8, V9, _V3R , _V4R , _V5R ) of the electrocardiogram can be obtained.

In this embodiment, in order to calculate the additional guidance of a specific person, it is ideal to obtain the transfer coefficient α of the specific person in advance, accumulate this as data, and use it for the calculation. A highly accurate calculation result can be obtained. However, it may be impractical to first determine the personal transfer coefficient α and store it as data so that it can be used for calculations as needed. Therefore, in this case, the transfer coefficient α of the average human model is obtained and stored as data so that it can be used for calculation as needed. For this reason, electrocardiograms are measured from a large number of people, for example, as a mass screening, among the standard 12 leads, limb lead 2 leads I and II, chest lead 2 leads V2 and V4, and additional lead potentials V7 and V8, An electrocardiogram signal composed of V9, V _3R , V _4R , and V _5R is collected, and a database for calculating the calculation transfer coefficient α is constructed. Then, the data of the entire group accumulated in this database is applied to the above equation (4-5) to obtain an average α value, and this α value is used as a calculation means for calculating the additional induced potential. Store it in the required memory to output.

  In the above-described embodiment, when the additional lead electrocardiogram is derived, the V7, V8, and V9 leads in the electrode part on the extension line of the chest lead, and the V3R in the electrode part in a symmetrical position with the electrode part of the chest lead. However, the present invention is not limited to these, and can be applied to derivation of other additional lead electrocardiograms. In the above-described embodiment, the additional lead electrocardiogram is calculated from the standard lead potentials I, II, V2, and V4. However, the present invention is not limited to this, and other standard 12 lead limb 2 lead and chest 2 lead. Various combinations with these are also possible. In particular, I, II, V2, and V5 induction combinations, I, II, V2, and V6 induction combinations, I, II, V1, and V4 induction combinations, I, II, V1, and V5 induction combinations, And the combination of I, II, V1, and V6 induction is sufficiently practical.

Next, based on the method for deriving the additional lead electrocardiogram described in the fourth embodiment, the additional lead electrocardiogram and the standard 12 lead electrocardiogram are provided with an additional lead function configured to be displayed on the display monitor simultaneously. The electrocardiograph will be described.
[Configuration of an electrocardiograph equipped with a function for deriving an additional electrocardiogram]

  FIG. 10 is a system configuration diagram of an electrocardiograph having a function of deriving an additional lead electrocardiogram according to the fourth embodiment. That is, in FIG. 10, reference numeral 10A indicates a potential detector for measuring an electrocardiogram signal as a standard induction potential of a standard 12-lead electrocardiogram. This potential detector 10A has 10 or less electrodes mounted on the body surface of a living body for obtaining a standard induced potential of a standard 12-lead electrocardiogram, that is, a subset of standard 12-lead ECG potential detectors (for example, RA, LA, 6) (RL, LL, V2, and V4) and functions as a biological amplifier and an A / D converter for measuring electrocardiogram signals (I, II, V2, and V4).

The electrocardiogram signals (I, II, V2, V4) of the standard 12 lead potential detected by the potential detector 10A are stored in the electrocardiogram signal memory 12A and input to the standard 12 lead electrocardiogram calculation means 14A. The The electrocardiogram signals (I, II, V2, V4) stored in the electrocardiogram signal memory 12A are input to the additional lead electrocardiogram calculation means 16A, and the electrocardiogram signals (V7, V8, V9, _V3R , _V4R , _V5R ) are calculated by calculation.

Then, as will be described in detail later, an electrocardiogram signal (I, II, V2, V4) as a standard induction potential of a standard 12-lead electrocardiogram measured using a calculation transfer coefficient α set in advance in the memory 15A. ), The electrocardiogram signals (V7, V8, V9, _V3R , _V4R , _V5R ) as the additional induction potential of the additional electrocardiogram are calculated by the above equation (4-1).

  In this way, the electrocardiogram signal as the additional lead potential calculated by the additional lead electrocardiogram calculation unit 16A is input to the additional lead electrocardiogram waveform output unit 18A. The electrocardiogram signal as the standard 12-lead potential calculated by the standard 12-lead electrocardiogram calculation means 14A is input to the standard 12-lead electrocardiogram waveform output means 20A.

  Then, the ECG waveform outputs output from the standard 12-lead ECG waveform output means 20A and the additional-lead ECG waveform output means 18A are respectively input to the display monitor 22A, and the standard 12-lead ECG and the additional-lead ECG are simultaneously imaged. Is displayed.

However, the additional lead electrocardiogram calculation means 16A uses the potential detector 10A to perform the two lead I and II of the limb lead and the two leads V2 and V4 of the chest lead among the standard 12 leads and the additional lead potentials V7, V8, V9, and V9. _An electrocardiogram signal composed of _3R , V _4R , V _5R is collected from a large number of patients or healthy persons, and a database for calculating a transmission coefficient α for calculation of an average model is constructed. The calculated calculation transfer coefficient α is stored in the memory 15A. In this case, the calculation transmission coefficient α can be calculated by the equation (4-5).

  The system operation of the electrocardiograph having the additional guidance function configured as described above will be described with reference to the flowchart shown in FIG.

  First, in an electrocardiograph having an additional induction function, an electrocardiogram signal (I, II, V2, V4) as a standard induction potential of a patient's standard 12-lead electrocardiogram is measured by the potential detector 10A (STEP- 401). The electrocardiogram signals (I, II, V2, V4) of the measured standard induction potential are stored in the electrocardiogram signal memory 12A (STEP-402).

Next, the calculation transmission coefficient α preset in the memory 15A is input to the additional lead electrocardiogram calculation means 16A (STEP-403), and the electrocardiogram signals (I, II, V2) stored in the electrocardiogram signal memory 12A. , V4) are also input to the additional lead electrocardiogram calculation means 16A, the supplementary lead electrocardiogram calculation means 16A, based on the electrocardiogram signals (I, II, V2, V4) and the transmission count α, The sign (V7, V8, V9, _V3R , _V4R , _V5R ) is calculated (STEP-404). The operation of the electrocardiogram signals (V7, V8, V9, V _3R , V _4R , V _5R ) of the additional electrocardiogram by the additional electrocardiogram computing means 16A is as follows based on the equation (4-4). Can be calculated.

V7 _{induction: V 7 = α 7I V I} + α 7II V II + α 7V2 V V2 + α 7V4 V V4 ... (4-6)
V8 induction: V ₈ = α _8I V _I + α _8II V _II + α _8V2 V _V2 + α _8V4 V _V4 (4-7)
V9 induction: V ₉ = α _9I V _I + α _9II V _II + α _9V2 V _V2 + α _9V4 V _V4 (4-8)
V _3R induction: V _3R = α _3RI V _I + α _3RII V _II + α _3RV2 V _V2 + α _3RV4 V _V4 (4-9)
V _{4R induction: V 4R = α 4RI V I} + α 4RII V II + α 4RV2 V V2 + α 4RV4 V V4 ... (4-10)
V _{5R induction: V 5R = α 5RI V I} + α 5RII V II + α 5RV2 V V2 + α 5RV4 V V4 ... (4-11)

  The electrocardiogram signals (I, II, V2, V4) of the standard induction potential stored in the electrocardiogram signal memory 12A are also input to the standard 12-lead electrocardiogram calculation means 14A, and the induction potential (I, II, III, V1, V2, V3, V4, V5, V6, aVR, aVL, aVF) are calculated by calculation (STEP-405). Here, the induction potentials V1, V3, V5, and V6 are obtained by calculation based on the relationship between the potential vector, the induction vector, and the heart vector.

Further, the electrocardiogram signals (V7, V8, V9, V _3R , V _4R , V _5R ) as the additional induction potentials of the additional induction electrocardiogram calculated by the additional induction electrocardiogram calculation means 16A are output by the additional induction electrocardiogram waveform output means 18A. The waveform is processed and input to the display monitor 22A (STEP-406). The electrocardiogram signals (I, II, III, V1, V2, V3, V4, V5, V6, aVR, aVL, aVF) as the induction potential of the standard 12-lead electrocardiogram calculated by the standard 12-lead electrocardiogram calculation means 14A are: Waveform processing (STEP-407) is performed by the standard 12-lead electrocardiogram waveform output means 20A and is input to the display monitor 22A (STEP-407). Further, the waveform-processed additional-lead ECG waveform output and the standard 12-lead ECG waveform output are simultaneously displayed on the display screen of the display monitor 22A (STEP-408).

  Electrocardiogram signals (I, II, V1 to V6) that are standard induction potentials of standard 12 leads measured based on the fourth embodiment, and V7, V8, V9 leads and V3R, V4R as additional lead electrocardiograms. The waveform diagram with the V5R induction is as shown in FIGS. A similar output waveform can be obtained by the third embodiment.

  That is, FIG. 12A shows the waveform of the electrocardiogram signals (I, II, V2, V4) measured from a certain patient. FIG. 12B shows V3R, V4R, and V5R lead waveforms as additional lead electrocardiograms calculated from the electrocardiogram signals (I, II, V2, and V4), and V3R, V4R, and V5R actually measured from the same patient. Each induction waveform is shown (the measured waveform is indicated by a thick solid line, and the portion overlapping the waveform calculated by the calculation is indicated by a thin solid line). FIG. 12 (c) shows the waveforms of the V7, V8, and V9 leads (shown by thin solid lines) as additional lead electrocardiograms calculated by the electrocardiogram signals (I, II, V2, and V4) and are measured from the same patient. In addition, V7, V8, and V9 lead waveforms (the measured waveform is indicated by a thick solid line, and the portion overlapping with the waveform calculated by calculation is indicated by a thin solid line). As a result, it was confirmed that the waveform of the additional electrocardiogram obtained by calculation based on the fourth embodiment and the waveform of the additional electrocardiogram obtained by actual measurement were extremely approximate.

  FIG. 13A shows the waveforms of the electrocardiogram signals (I, II, V2, V5) measured from another patient. FIG. 13 (b) shows V3R, V4R, and V5R lead waveforms as additional lead electrocardiograms calculated from the electrocardiogram signals (I, II, V2, and V5), and V3R, V4R, Each waveform of V5R induction is shown (the measured waveform is indicated by a thick solid line, and the portion overlapping with the waveform calculated by the calculation is indicated by a thin solid line). FIG. 13 (c) shows V7, V8, and V9 lead waveforms (shown by thin solid lines) as additional lead electrocardiograms calculated by the electrocardiogram signals (I, II, V2, and V5), and measurements from the same patient. Each of the V7, V8, and V9 induction waveforms (the measured waveform is indicated by a thick solid line, and the portion overlapping with the waveform calculated by the calculation is indicated by a thin solid line). As a result, it was confirmed that the waveform of the additional electrocardiogram obtained by calculation based on the fourth embodiment and the waveform of the additional electrocardiogram obtained by actual measurement were extremely approximate.

  FIG. 14A shows waveforms of electrocardiogram signals (I, II, V2, V6) measured from another patient. FIG. 14B shows V3R, V4R, and V5R lead waveforms as additional lead electrocardiograms calculated based on the electrocardiogram signals (I, II, V2, and V6), and V3R, V4R, Each waveform of V5R induction is shown (the measured waveform is indicated by a thick solid line, and the portion overlapping with the waveform calculated by the calculation is indicated by a thin solid line). FIG. 14 (c) shows V7, V8, and V9 lead waveforms (shown by thin solid lines) as additional lead electrocardiograms calculated from the electrocardiogram signals (I, II, V2, and V6), and measurements from the same patient. Each of the V7, V8, and V9 induction waveforms (the measured waveform is indicated by a thick solid line, and the portion overlapping with the waveform calculated by the calculation is indicated by a thin solid line). As a result, it was confirmed that the waveform of the additional electrocardiogram obtained by calculation based on the fourth embodiment and the waveform of the additional electrocardiogram obtained by actual measurement were extremely approximate.

  FIG. 15A shows the waveforms of electrocardiogram signals (I, II, V1, V5) measured from another patient. FIG. 15B shows V3R, V4R, and V5R lead waveforms as additional lead electrocardiograms calculated from the electrocardiogram signals (I, II, V1, and V5), and V3R, V4R, Each waveform of V5R induction is shown (the measured waveform is indicated by a thick solid line, and the portion overlapping with the waveform calculated by the calculation is indicated by a thin solid line). FIG. 15 (c) shows V7, V8, and V9 lead waveforms (shown by thin solid lines) as additional lead electrocardiograms calculated from the electrocardiogram signals (I, II, V1, and V5), and measurements from the same patient. Each of the V7, V8, and V9 induction waveforms (the measured waveform is indicated by a thick solid line, and the portion overlapping with the waveform calculated by the calculation is indicated by a thin solid line). As a result, it was confirmed that the waveform of the additional electrocardiogram obtained by calculation based on the fourth embodiment and the waveform of the additional electrocardiogram obtained by actual measurement were extremely approximate.

  FIG. 16A shows the waveforms of electrocardiogram signals (I, II, V1, V6) measured from another patient. FIG. 16B shows V3R, V4R, and V5R lead waveforms as additional lead electrocardiograms calculated based on the electrocardiogram signals (I, II, V1, and V6), and V3R, V4R, Each waveform of V5R induction is shown (the measured waveform is indicated by a thick solid line, and the portion overlapping with the waveform calculated by the calculation is indicated by a thin solid line). FIG. 16 (c) shows V7, V8, and V9 lead waveforms (shown by thin solid lines) as additional lead electrocardiograms calculated by the electrocardiogram signals (I, II, V1, and V6), and measurements from the same patient. Each of the V7, V8, and V9 induction waveforms (the measured waveform is indicated by a thick solid line, and the portion overlapping with the waveform calculated by the calculation is indicated by a thin solid line). As a result, it was confirmed that the waveform of the additional electrocardiogram obtained by calculation based on the fourth embodiment and the waveform of the additional electrocardiogram obtained by actual measurement were extremely approximate.

  FIG. 17A shows waveforms of electrocardiogram signals (I, II, V3, V4) measured from another patient. FIG. 17B shows V3R, V4R, and V5R lead waveforms as additional lead electrocardiograms calculated from the electrocardiogram signals (I, II, V3, and V4), and V3R, V4R, Each waveform of V5R induction is shown (the measured waveform is indicated by a thick solid line, and the portion overlapping with the waveform calculated by the calculation is indicated by a thin solid line). FIG. 17 (c) shows V7, V8, and V9 lead waveforms (shown by thin solid lines) as additional lead electrocardiograms calculated from the electrocardiogram signals (I, II, V3, and V4), and measurements from the same patient. Each of the V7, V8, and V9 induction waveforms (the measured waveform is indicated by a thick solid line, and the portion overlapping with the waveform calculated by the calculation is indicated by a thin solid line). As a result, it was confirmed that the waveform of the additional electrocardiogram obtained by calculation based on the fourth embodiment and the waveform of the additional electrocardiogram obtained by actual measurement were extremely approximate.

  FIG. 18A shows waveforms of electrocardiogram signals (I, II, V3, V5) measured from another patient. FIG. 18B shows V3R, V4R, and V5R lead waveforms as additional lead electrocardiograms calculated from the electrocardiogram signals (I, II, V3, and V5), and V3R, V4R, Each waveform of V5R induction is shown (the measured waveform is indicated by a thick solid line, and the portion overlapping with the waveform calculated by the calculation is indicated by a thin solid line). FIG. 18 (c) shows V7, V8, and V9 lead waveforms (shown by thin solid lines) as additional lead electrocardiograms calculated from the electrocardiogram signals (I, II, V3, and V5), and measurements from the same patient. Each of the V7, V8, and V9 induction waveforms (the measured waveform is indicated by a thick solid line, and the portion overlapping with the waveform calculated by the calculation is indicated by a thin solid line). As a result, it was confirmed that the waveform of the additional electrocardiogram obtained by calculation based on the fourth embodiment and the waveform of the additional electrocardiogram obtained by actual measurement were extremely approximate.

  The present invention is not limited to the above embodiment. In the above embodiment, among the standard induced potentials of the standard 12-lead ECG (including the modified 12-lead ECG), the I and II leads are selected from the limb leads and measured, and the two leads are selected from the chest lead and measured. Then, additional electrocardiograms were obtained from these leads. However, the present invention is not limited to the selection of such induction, and an electrode may be selected as appropriate, and the combination of induction I and III or combination of induction II and III may be selected for limb induction. At this time, the chest lead can be selected from the V1 to V6 leads in an appropriate combination. Further, the present invention can apply the limb guidance in the Mason-Likar modified 12 lead to obtain an additional lead ECG of the modified 12 lead electrocardiogram in the case of an exercise load test or the like. Further, the function for calculating the additional lead according to the present invention can be added to an electrocardiograph operating in a hospital facility or the like, and can be sold as an optional function of the electrocardiograph. Furthermore, the function of calculating this additional guidance can be added to a biological information monitor that measures other biological information in addition to the electrocardiogram. In addition, various design changes can be made without departing from the spirit of the present invention.

  As described above, the electrocardiograph of the present invention is measured by the potential detector that measures at least any two evoked potentials of the limb leads and at least any two evoked potentials of the chest lead, and the potential detector. And an additional induction potential calculation means for calculating an additional induction potential based on the induced potential, and the additional induction potential calculation means uses a transmission coefficient α representing a relationship between inductions by the potential detector. An additional induction function is provided, wherein the additional induction potential is calculated based on the measured induction potential.

In the electrocardiograph of the present invention, it is preferable that the transmission coefficient α is V _i = Σα _{i, j} V _j (where i is an induction number for additional induction and j is an induction number for 12 leads).

  Further, the additional lead electrocardiogram calculation method of the present invention is based on the measured limb lead at least any two lead potentials and the chest lead lead at least any two lead potentials. It is preferable to calculate the additional induced potential using

In the present invention, the transmission coefficient α is preferably V _i = Σα _{i, j} V _j (where i is an induction number for additional induction and j is an induction number for 12 induction).

In the present invention, it is preferable that the additional induction potential includes at least one of V7 to V9 induction, V _3R , V _4R , V _5R , and V _6R induction.

  An electrocardiograph according to the present invention comprises an electrode attached to the body surface of a living body to obtain a standard 12 electrocardiogram waveform, a potential detector for measuring a standard 12-lead electrocardiogram signal from each of the electrodes, An electrocardiogram signal memory for storing the electrocardiogram signals of the standard 12-lead electrocardiogram measured by the potential detector, and a waveform of the standard 12-lead electrocardiogram by inputting an electrocardiogram signal obtained via the electrocardiogram signal memory. A standard 12-lead ECG waveform means for processing and an ECG signal obtained via the ECG signal memory are inputted, and an ECG signal of the additional lead ECG is calculated based on a calculation parameter α set in advance. Additional-lead ECG signal calculating means, additional-lead ECG waveform output means for inputting the ECG signal calculated by the additional-lead ECG signal calculating means and performing waveform processing of the additional-lead ECG, and the standard 2 lead ECG waveform output means and said additional lead ECG waveform output device and the electrocardiogram waveform output which is output from and a display monitor for simultaneously screen display, respectively.

Further, in the present invention, the signal potential of the additional lead ECG, V7 to V9 _{induction, V 3R, V 4R, V} 5R, preferably contains one inductive least one of _{V 6R} induction.

  According to the present invention, it is possible to easily calculate and derive the additional guidance without attaching the additional guidance electrode to the patient.

FIG. 1 is a system configuration diagram showing a first embodiment of an electrocardiograph according to the present invention. FIG. 2 is a flowchart showing the operation of the electrocardiograph shown in FIG. FIG. 3 is a waveform diagram for comparing the additional lead ECG derived from the V7 lead derived from the first embodiment with the additional lead ECG based on the actual measurement value. FIG. 4 is a waveform diagram for comparing the V8 lead additional electrocardiogram derived by the first embodiment with the additional lead electrocardiogram based on the actual measurement value. FIG. 5 is a waveform diagram for comparing the additional lead electrocardiogram derived from the first embodiment with the V9 lead and the additional lead electrocardiogram based on the actual measurement value. FIG. 6 is a system configuration diagram showing a second embodiment of the electrocardiograph according to the present invention. FIG. 7 is a flowchart showing the operation of the electrocardiograph shown in FIG. FIG. 8 is a system configuration diagram showing a third embodiment of the electrocardiograph according to the present invention. FIG. 9 is a flowchart showing the operation of the electrocardiograph shown in FIG. FIG. 10 is a system configuration diagram showing a fourth embodiment of the electrocardiograph according to the present invention. FIG. 11 is a flowchart showing the operation of the electrocardiograph shown in FIG. In FIG. 12, (a) shows the measured waveform of the electrocardiogram signals (I, II, V2, V4) of the standard 12-lead ECG, and (b) shows the calculation of the additional lead ECGs V3R, V4R, V5R. (C) shows the calculated waveform and the actually measured waveform of the additional lead electrocardiograms V7, V8, and V9. In FIG. 13, (a) shows the measured waveform of the electrocardiogram signals (I, II, V2, V5) of the standard 12-lead electrocardiogram, and (b) shows the calculation of the additional lead electrocardiograms V3R, V4R, V5R. (C) shows the calculated waveform and the actually measured waveform of the additional lead electrocardiograms V7, V8, and V9. 14A shows the measured waveforms of the electrocardiogram signals (I, II, V2, V6) of the standard 12-lead ECG, and FIG. 14B shows the calculation of the additional lead ECGs V3R, V4R, V5R. (C) shows the calculated waveform and the actually measured waveform of the additional lead electrocardiograms V7, V8, and V9. In FIG. 15, (a) shows the measured waveform of the electrocardiogram signals (I, II, V1, V5) of the standard 12-lead electrocardiogram, and (b) shows the calculation of the additional lead electrocardiograms V3R, V4R, V5R. (C) shows the calculated waveform and the actually measured waveform of the additional lead electrocardiograms V7, V8, and V9. In FIG. 16, (a) shows the measured waveform of the electrocardiogram signals (I, II, V1, V6) of the standard 12-lead electrocardiogram, and (b) shows the calculation of the additional lead electrocardiograms V3R, V4R, V5R leads. (C) shows the calculated waveform and the actually measured waveform of the additional lead electrocardiograms V7, V8, and V9. In FIG. 17, (a) shows the measured waveform of the electrocardiogram signals (I, II, V3, V4) of the standard 12-lead ECG, and (b) shows the calculation of the additional lead ECGs V3R, V4R, V5R. (C) shows the calculated waveform and the actually measured waveform of the additional lead electrocardiograms V7, V8, and V9. In FIG. 18, (a) shows the measured waveform of the electrocardiogram signals (I, II, V3, V5) of the standard 12-lead ECG, and (b) shows the calculation of the additional lead ECGs V3R, V4R, V5R. (C) shows the calculated waveform and the actually measured waveform of the additional lead electrocardiograms V7, V8, and V9.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Potential detector, 12 ... Electrocardiogram signal memory, 14 ... Standard 12 lead electrocardiogram waveform output means, 15 ... Memory, 16 ... Additional lead electrocardiogram calculation means, 18 ... Additional lead electrocardiogram waveform output means, 20 ... Display monitor.

Claims (5)

Of the combinations of limb lead induction potentials I and II and chest lead potentials V2 and V4, V2 and V5, V2 and V6, V1 and V5, V1 and V6, V3 and V4, or V3 and V5 in the 12-lead ECG A potential detector to measure either
An additional induction potential calculating means for calculating an additional induction potential based on the induction potential of the 12-lead electrocardiogram measured by the potential detector;
The additional induction potential calculating means calculates the additional induction potential based on the induction potential measured by the potential detector using Equation 1 and has a 12-lead electrocardiogram having an additional induction function. Total.

However, i is the induction number of additional induction (V7, V8, V9, V3R, V4R, V5R), j is the actual induction number of standard 12 induction (I, II, V1, V2, V3, V4, V5, V6) Indicates. Α is a transmission coefficient representing the relationship between inductions , and is added in advance to any one of the induction potentials I and II of the limb inductions and the chest induction potentials V1 to V6 in the standard 12 inductions. This is a transmission coefficient obtained by actually measuring the inductions V7, V8, V9, V3R, V4R, and V5R and substituting them in Equation 2 to obtain the solution of the least squares method.
A = (V ^T jVj) −1V ^T jVi (2)
Where A = {αi, j}
Vj = {Vs, j}
Vi = {Vi, s}
T indicates vector transposition and s indicates a data sample.   The 12-lead electrocardiograph according to claim 1, wherein the additional induction potential includes at least one of V7 to V9 induction, V3R, V4R, V5R, and V6R induction. An electrode mounted on the body surface of a living body to obtain a standard 12 ECG induced waveform;
Additional lead electrocardiogram waveform output means for inputting the induced potential calculated by the additional lead potential calculating means and performing waveform processing of the additional lead electrocardiogram;
Standard 12-lead ECG waveform output means for performing waveform processing of a standard 12-lead ECG;
A display monitor for simultaneously displaying the electrocardiogram waveform outputs outputted from the standard 12-lead ECG waveform output means and the additional lead ECG waveform output means, respectively,
The 12-lead electrocardiograph with additional induction function according to claim 1 or 2, wherein the potential detector measures an induced potential from each of the electrodes. Of the combinations of limb lead induction potentials I and II and chest lead potentials V2 and V4, V2 and V5, V2 and V6, V1 and V5, V1 and V6, V3 and V4, or V3 and V5 in the 12-lead ECG A potential detection step for measuring either
An additional induction potential calculation step for calculating an additional induction potential based on the induction potential of the 12-lead electrocardiogram measured by the potential detection step ;
In the additional induced electrocardiogram derivation method, the additional induced potential calculating step calculates the additional induced potential based on the induced potential measured in the potential detecting step using Equation 3.

However, i is the induction number of additional induction (V7, V8, V9, V3R, V4R, V5R), j is the actual induction number of standard 12 induction (I, II, V1, V2, V3, V4, V5, V6) Indicates. Α is a transmission coefficient representing the relationship between inductions , and is added in advance to any one of the induction potentials I and II of the limb inductions and the chest induction potentials V1 to V6 in the standard 12 inductions. This is a transmission coefficient obtained by actually measuring the inductions V7, V8, V9, V3R, V4R, and V5R and substituting them in Equation 4, respectively, as a solution of the least square method.
A = (V ^T jVj) −1V ^T jVi (4)
Where A = {αi, j}
Vj = {Vs, j}
Vi = {Vi, s}
T indicates vector transposition and s indicates a data sample. The method according to claim 4, wherein the additional induction potential includes at least one of V7 to V9 induction, V3R, V4R, V5R, and V6R induction.

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