Atrial Fibrillation Defibrillation System

Abstract

To provide a system capable of accurately timing the execution of defibrillation.SOLUTION: An atrial fibrillation defibrillation system comprises a reception unit for receiving an electrocardiogram signal, and a control unit. The control unit executes steps of sampling the electrocardiogram signal with a constant frequency from the reception unit and acquiring a sampling value (S1), calculating the inclination of an R wave in the electrocardiogram signal by using the sampling value (S3), detecting the peak of the R wave based on the sampling value in a case where the positiveness and negativeness of the inclination is reversed (S7), calculating the period of the R wave (S9), and performing a defibrillation process in a case of detecting an irregularity of the period (S15).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a configuration of an atrial defibrillation system and a program for controlling the same. [Background technology]

[0002] Atrial fibrillation in humans or animals is likely to occur during cardiac catheterization, and if left untreated for a long time, thrombi and other factors may form, resulting in serious pathologies such as cerebral infarction, pulmonary infarction, and lower limb arterial thrombosis. Therefore, it is desirable to perform defibrillation promptly during surgery to prevent atrial fibrillation. However, atrial fibrillation can also cause an unstable state in which it occurs during surgery, subsides due to physical impact, or subsides naturally. Even when atrial fibrillation occurs, the movement of the ventricles in the heart is generally normal, and atrial fibrillation does not cause loss of consciousness. Therefore, in order to avoid the induction of ventricular fibrillation by defibrillation, it is important not to perform defibrillation in a state other than atrial fibrillation, for example, in a state of atrial flutter.

[0003] From this perspective, a technique is used in which an electrocardiogram signal is observed to determine whether or not atrial fibrillation is occurring, and defibrillation of the atrial fibrillation is performed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5900974 Summary of the Invention [Problem to be solved by the invention]

[0005] The above technology measures the peak of the R wave and determines the timing for defibrillation. However, the peak cannot be measured accurately, which may lead to an incorrect determination of whether atrial fibrillation has occurred or an inaccurate timing for defibrillation.

[0006] The present invention has been made in view of the above problems, and has an object to provide a system that can accurately time the execution of defibrillation. [Means for solving the problem]

[0007] One embodiment of the present invention is an atrial fibrillation defibrillation system that includes a receiving unit that receives an electrocardiogram signal and a control unit, wherein the control unit executes the following processes: a process of sampling the electrocardiogram signal from the receiving unit at a constant frequency to obtain sampling values; a calculation process of calculating the slope of an R wave in the electrocardiogram signal using the sampled value; a peak detection process of detecting a peak of the R wave based on the sampled value when the positive / negative sign of the slope is reversed; a period detection process of detecting the period of the R wave; and a defibrillation process of determining that atrial fibrillation occurs and defibrillating the atrium when it is detected that the period is disrupted. Effect of the Invention

[0008] According to the above configuration, it is possible to provide a system that can accurately time the execution of defibrillation. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram of an atrial defibrillation system according to an embodiment. [Diagram 2] FIG. 2 is an enlarged view of a catheter according to an embodiment. [Diagram 3] 4 is a process flow of control according to the embodiment. [Figure 4] FIG. 1 is a diagram showing an electrocardiogram waveform. [Diagram 5] FIG. 1 is a diagram showing a formula used to determine an R wave. [Figure 6] FIG. 1 shows electrocardiogram waveforms in (a) atrial fibrillation and (b) atrial flutter. [Figure 7] FIG. 4 is an enlarged view of a catheter according to a first modified example. [Figure 8] FIG. 11 is a block diagram of an atrial defibrillation system according to a second modified example. [Figure 9] FIG. 11 is a block diagram of an atrial defibrillation system according to a third modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <Embodiment> An atrial defibrillation system 1 according to an embodiment of the present invention will be described below with reference to FIGS.

[0011] 1 and 2, the atrial fibrillation defibrillation system 1 includes a power supply device 10, an electrocardiogram acquisition circuit 23, a control circuit 24, an impedance detection circuit 25, switching elements 31-35, a catheter 40, and start buttons St1 and St2. The atrial fibrillation defibrillation system 1 is connected to an external electrocardiograph device 101 and an IEGM device 102 via terminals (shown as white circles in the figures).

[0012] Power supply device 10 is a device that supplies power to catheter 40, and includes a charge circuit 11, a charge / discharge capacitor 12, and a pulse generating circuit 13. Charge / discharge capacitor 12 and pulse generating circuit 13 are each electrically insulated from control circuit 24. A step-up transformer (insulation transformer) provides insulation between charge circuit 11 and charge / discharge capacitor 12, and between control circuit 24 and pulse generating circuit 13, preventing noise generated from the pulse generating circuit from flowing to charge circuit 11 and control circuit 24.

[0013] The charge circuit 11 is connected to the charge / discharge capacitor 12 and supplies a voltage used for defibrillation.

[0014] The charge / discharge capacitor 12 is a capacitor that charges and discharges a defibrillation voltage, and supplies the defibrillation voltage to the pulse generating circuit 13. The pulse generating circuit 13 has a function of applying the pulse voltage to the catheter 40 via the switching elements 31-35.

[0015] The electrocardiogram acquisition circuit 23 is connected to the electrocardiograph device 101 via a terminal, and transmits the received electrocardiogram signal to the control circuit 24.

[0016] The impedance detection circuit 25 has a function of measuring the impedance of the cardiac tissue between the first electrode group 41 and the second electrode group 42 (described later) and transmitting the measured impedance to the control circuit 24.

[0017] The control circuit 24 has a function of receiving and analyzing an electrocardiogram signal and impedance via the electrocardiogram acquisition circuit 23 and the impedance detection circuit 25.

[0018] 1, the control circuit 24 is connected to the switching elements 31-35 and the charge circuit 11 and has the function of controlling each of them. For example, the control of defibrillation is started based on the operation of start buttons St1 and St2 by the user. The control circuit 24 includes a calculation device, and operates by starting a program from a storage unit (not shown), thereby controlling the atrial fibrillation defibrillation system 1. Specific details of the control will be described later.

[0019] Switching elements 31-35 are connected to control circuit 24 via terminals a and b, respectively, and have the function of switching on and off the application of voltage to catheter 40 under the control of control circuit 24. Switching element 34 is made up of eight switching elements. Similarly, switching element 35 is also made up of eight switching elements.

[0020] The electrocardiograph device 101 acquires minute electromotive forces generated in association with cardiac activity from electrodes placed on the body surface (not shown), amplifies the electrocardiogram signals, and collects, measures, and analyzes them, and further transmits the electrocardiogram signals to the control circuit 24. The electrocardiograph device 101 can also be configured to display an electrocardiogram waveform using a display device (not shown).

[0021] The IEGM device 102 is a device that collects, measures, and analyzes intracardiac electrograms (IEGMs) that represent electrical activity within tissue sensed by electrodes, and has a pacing function.

[0022] As shown in FIG. 2, the catheter 40 includes a first electrode group 41, a second electrode group 42, a first tip 43, a second tip 44, and tubular tubes 45 and 46 formed of an insulator.

[0023] The first electrode group 41 is composed of eight annular electrodes attached to the outer periphery of the tube 45, and the eight annular electrodes are respectively connected to the eight switching elements 35. The first electrode group 41 is electrically connected to the switching elements 35 via lead wires (not shown).

[0024] The second electrode group 42 is composed of eight annular electrodes attached to the outer periphery of the tube 46, and the eight annular electrodes are respectively connected to the eight switching elements 34. The second electrode group 42 is electrically connected to the switching elements 34 via lead wires (not shown).

[0025] The first tip 43 and the second tip 44 are ring-shaped electrodes attached to the distal ends of the tubes 45, 46, respectively, and have the function of applying a pacing voltage into the cardiac chamber. The first tip 43 and the second tip 44 are disposed apart from each other at the distal ends of the tubes 45, 46. The first tip 43 and the second tip 44 are connected to the switching elements 33, 32, respectively, via leads (not shown).

[0026] 〔control〕 In the atrial defibrillation defibrillation system 1 configured as above, the control performed by the control circuit 24 will be described in detail below with reference to the flow chart of FIG.

[0027] The control is performed with the catheter 40 placed at a predetermined position in the patient's heart. A user, who is a medical professional, inserts the catheter 40 into the body so that the first electrode group 41 is placed in the coronary sinus of the heart and the second electrode group 42 is placed in the right atrium, right atrial appendage, or base of the superior vena cava of the heart.

[0028] When the control circuit 24 detects the operation of the switches St1 and St2 by the user, it executes the following control.

[0029] In step S1, the control circuit 24 samples the electrocardiogram signal received from the electrocardiograph device 101 at a constant frequency, and measures the voltage or potential of the electrocardiogram signal (hereinafter referred to as the "sampled value") and time.

[0030] The sampling frequency is set to, for example, 200 Hz. + This is to grasp the response time of the channel (sodium channel) response and accurately detect the ventricular signal (R wave). + The time from the onset to the peak of the R wave by the channel is about 0.5 to 2.0 ms (milliseconds) when the cell potential changes from about -70 mV (millivolts) to about +30 mV, which is the fastest change in cell potential. When analyzing electrocardiogram signals on the body surface, the electrocardiograph device 101 has a band limit of about 100 Hz, so the actual NaCl of the myocardium in the heart chamber is not measured. + Unlike the response time of the channel and the voltage level, the rise time of the R wave is longer, but even in that case, it is only about 2 ms or more. However, the R wave shows the fastest change in the electrocardiogram waveform. From this point of view, the sampling frequency is set to Na + It is set based on the response time due to the channel response. For example, if the band limit is 100 Hz, a sampling frequency of 200 Hz or more is set.

[0031] Next, the control circuit 24 uses the acquired sampled values ​​to obtain differential values ​​of the electrocardiogram waveform (S3). Specifically, as shown in Fig. 4, the control circuit 24 linearly interpolates the sampled value with the immediately preceding sampled value to calculate the slope of the waveform. Fig. 4 shows the sequential R of the sampled values ​​from the n-2th to the n+1th. n-2 ~R n+1 These slopes can be obtained by dividing the difference between the sampled values ​​(i.e., potentials) by the sampling time interval dt, as shown in equation (1) in FIGS.

[0032] In step S5, the control circuit 24 judges whether a waveform corresponding to an R wave has been acquired. Specifically, as shown in equations (2) and (3) in FIG. 5, the control circuit 24 compares the slope of the waveform acquired in step S3 with a normal slope range preset by a threshold value. Alternatively, as shown in equations (4) and (5) in FIG. 5, the control circuit 24 compares the time when the slope is positive (rising) or the time when the slope is negative (falling) with a normal range preset by a threshold value. Note that in step S5, the judgment condition may be that all or some of the equations (2) to (5) are satisfied.

[0033] The rise and fall times or slopes of the R wave are + This falls within a substantially constant range according to the response time of the channel. Therefore, the control circuit 24 can accurately determine whether the measured waveform is an R wave by comparing the rise or fall time with a time that is considered to be in a normal range, or by determining whether the rise or fall slope falls within a predetermined range.

[0034] The normal range of time or the predetermined range of slope to be compared can be set based on the shape of the R wave measured in advance from the individual whose electrocardiogram signal is measured. Alternatively, the normal range of time or the predetermined range of slope may be set in advance from the general shape of the electrocardiogram waveform.

[0035] When it is determined that a waveform corresponding to an R wave has been acquired (S5: YES), the control circuit 24 calculates the peak of the acquired waveform (S7). The peak of the waveform is the sampling point R n Alternatively, the intersection point of the falling waveform and the rising waveform can be calculated to determine the peak position (i.e., the peak potential and time).

[0036] If it is determined that the detected wave is not an R wave (S5: NO), the control circuit 24 returns the process to step S1 and continues sampling of the electrocardiogram signal.

[0037] In step S9, the control circuit 24 calculates the period of the R wave. The period of the R wave is calculated by sequentially measuring the time intervals between the peaks of a plurality of acquired R waves, as shown in FIG.

[0038] In the next step S11, the control circuit 24 determines whether or not the period of the R wave is fluctuating.

[0039] If the R-wave period falls within a certain range (S11: NO), the control circuit 24 returns to step S1 and continues sampling of the electrocardiogram waveform. If the heart is beating normally or if atrial flutter is occurring as shown in Fig. 6(b), the R-wave period is constant. In such cases, there is no need to perform defibrillation, and the control circuit 24 continues sampling without performing defibrillation.

[0040] On the other hand, if the R wave period is not within the certain range (S11: YES), it is considered that atrial fibrillation is occurring as shown in FIG. 6(a), and therefore the control circuit 24 performs defibrillation in step S13.

[0041] In the defibrillation process (S13), the control circuit 24 controls the power supply device 10 and the switching elements 31 to 35 to apply pulse voltages of opposite polarities from the first electrode group 41 and the second electrode group 42 to the inside of the cardiac cavity, thereby performing defibrillation.

[0042] Defibrillation should be performed during the absolute refractory period. In particular, it is necessary to avoid applying a strong electrical stimulus to the ventricle during the transition from the absolute refractory period to the relative refractory period (also called shock on T), because this can induce ventricular fibrillation.

[0043] However, a signal delay occurs due to a bandpass filter of the electrocardiograph device 101, and the detection of the R wave by the control circuit 24 is delayed from the actual intraventricular potential change occurring in the body. Taking this signal delay into consideration, the control circuit 24 performs defibrillation at the timing when the absolute refractory period in the acquired electrocardiogram waveform becomes short and the waveform where the R wave changes from rising to falling is acquired. This allows appropriate defibrillation to be performed while avoiding shock onT.

[0044] After defibrillation is performed, the control circuit 24 applies a pacing pulse voltage at a cycle corresponding to the normal heart rate, and maintains normal ventricular movement (S15). The control circuit 24 uses the first chip 43 and the second chip 44 to apply a pulse voltage into the cardiac chamber at a cycle corresponding to the normal heart rate, for example, at a constant frequency of 60 to 90 beats / min, using the pacing pulses output from the IEGM device 102. In detail, the pacing pulse voltage supplied from the power supply device 10 is supplied to the first chip 43 and the second chip 44 via the switching elements 33 and 32. Voltages of opposite polarities are applied to the cardiac chamber at a constant cycle from the first chip 43 and the second chip 44.

[0045] <Effects> The atrial fibrillation defibrillation system 1 according to the embodiment includes an electrocardiogram acquisition circuit 23 (corresponding to a receiver of the present invention) that receives an electrocardiogram signal, and a control circuit 24 (corresponding to a control unit). The control circuit 24 executes a process (S1) of sampling the electrocardiogram signal from the electrocardiogram acquisition circuit 23 at regular intervals to acquire sampled values, and a calculation process (S3, S5) of calculating the slope of an R wave in the electrocardiogram signal using the sampled values, and detects the peak of an R wave based on the sampled values ​​when the positive and negative of the slope are inverted (S7).

[0046] The above configuration makes it possible to accurately grasp the peak of the R wave. Therefore, it is possible to accurately grasp the waveform of the electrocardiogram and judge whether atrial fibrillation is occurring. In particular, since the R wave is detected from the slope of the waveform, it is possible to reliably detect the R wave even if the potential at the peak of the R wave fluctuates.

[0047] For example, there is a conventional method for grasping an R wave by comparing the potential of a waveform with a threshold value, but with such a method, if the potential at the peak of the R wave fluctuates due to the influence of breathing or the like and falls below the threshold value, the R wave cannot be detected. Also, if the threshold value is set too small, signals other than the R wave may be mistaken for an R wave. Furthermore, there is a risk that a wave that suddenly exceeds the threshold value, which occurs when external noise occurs or an external stimulus is applied to the heart, may be mistaken for an R wave.

[0048] On the other hand, in the embodiment, R-wave detection can be performed accurately, and the possibility of performing defibrillation when atrial fibrillation is not occurring, or performing defibrillation at the wrong timing, such as on a T-wave, can be reduced. In addition, in the conventional method, it was necessary to perform long-term sampling for each individual in order to set the potential threshold, but in the above configuration, such long-term sampling is not necessary. In addition, if it is external noise, Na + Since the slope is larger than the R wave change corresponding to the channel, it can be distinguished from the R wave. Also, in the case of a premature ventricular contraction, the direction of the R wave is the opposite direction, so first the negative slope occurs, and then the positive slope occurs, so the above-mentioned changes such as the premature ventricular contraction can be ignored.

[0049] The control circuit 24 executes a process of comparing the slope with a predetermined range (S5), and executes a peak detection process if the slope is within the predetermined range. Alternatively, the control circuit 24 detects the rise time or fall time of the R wave based on the sampled value (S3), and compares the rise time or fall time with a normal range (S5). If the rise time or fall time is within the normal range, the control circuit 24 executes a peak detection process.

[0050] The above composition is the Na + This is based on the fact that the channel response is invariant. + Since the channel response is constant, the slope of the rising edge or the slope of the falling edge of the R wave always falls within a certain range. Therefore, by checking whether the slope of the rising edge or the slope of the falling edge falls within a predetermined range, it is possible to accurately distinguish between R waves and waves other than R waves. For example, when an unnecessary extrasystole of the heart occurs, the R wave falls and then rises. In such a case, it can be determined that the R wave is not normal by comparing the slope with a predetermined range.

[0051] For the same reason, the rise time or fall time of an R wave always falls within a certain range, so it is possible to accurately distinguish between R waves and waves other than R waves by checking whether the rise time or fall time falls within a normal range.

[0052] In the embodiment, it is stated that the sampling frequency is desirably 200 Hz or higher.

[0053] Na + The time from the onset to the peak of the R wave by the channel is about 0.5 to 2.0 ms (milliseconds) when the cell potential changes from about -70 mV (millivolts) to about +30 mV, which is the fastest change in cell potential. When analyzing electrocardiogram signals on the body surface, the electrocardiograph device 101 has a band limit of about 100 Hz, so the actual NaCl of the myocardium in the heart chamber is not measured. +Unlike the channel response time and voltage level, the rise time of the R wave is large. Therefore, when analyzing external ECG waveforms, a sampling frequency of 200 Hz or more is required to accurately grasp the shape of the R wave and capture its peak.

[0054] In this embodiment, the device further includes a catheter 40 that is inserted into a cardiac cavity to perform defibrillation of atrial fibrillation, and the control circuit 24 executes a process (S9) of calculating the period at which the peak of an R wave occurs. Furthermore, the control circuit 24 does not perform defibrillation when the period of the R wave is constant, and performs defibrillation using the catheter 40 when the period of the R wave varies (S11, S13).

[0055] In the above configuration, defibrillation is performed by observing the fluctuation in the R wave cycle, making it possible to accurately determine whether atrial fibrillation is occurring and to perform defibrillation.

[0056] In the defibrillation process, the control circuit 24 performs the defibrillation within the absolute refractory period. Also, in the defibrillation process, the control circuit 24 takes into consideration the delay of the electrocardiogram signal and performs the defibrillation at a timing when the absolute refractory period becomes short and a waveform with a falling R wave is acquired.

[0057] Defibrillation is preferably performed during the absolute refractory period. In particular, it is necessary to avoid applying a strong electrical stimulus to the ventricle during the transition from the absolute refractory period to the relative refractory period, i.e., shock onT, because this induces ventricular fibrillation. In the embodiment, the above-mentioned configuration makes it possible to avoid shock onT and perform defibrillation at an appropriate timing.

[0058] After the defibrillation process, the control circuit 24 can execute a process (S13) of applying pacing pulses output from the IEGM device 102, for example, pacing pulses of 60 to 90 times per minute, to the cardiac chamber from the first tip 43 and the second tip 44 of the catheter 40.

[0059] Since the catheter 40 has a first tip 43 and a second tip 44 which are electrodes dedicated to pacing pulses, it is possible to apply a pacing pulse voltage at an appropriate position within the heart chamber.

[0060] In the above embodiment, the catheter 40 has an insulating tube 45 and first and second electrode groups 41, 42 each consisting of a plurality of ring-shaped electrodes attached to the tube 45. The first and second electrode groups 41, 42 have the first electrode group 41 disposed in the coronary sinus of the heart, and the second electrode group 42 disposed in the right atrium, right atrial appendage, or base of the superior vena cava of the heart.

[0061] The atrial fibrillation defibrillation system 1 further includes a power supply unit 10 having a charging circuit 11 for charging a defibrillation voltage, a capacitor 12 that is electrically insulated from the control circuit 24 and charges and discharges the defibrillation voltage, and a pulse generating circuit 13 that is electrically insulated from the control circuit 24 and outputs pulses to the first and second electrode groups 41, 42.

[0062] In the above configuration, the control circuit 24 is insulated from the circuit that passes the defibrillation voltage, which prevents noise from being generated in the control circuit 24. This allows accurate operation, analysis, and control to be performed.

[0063] <Variation 1> In the above embodiment, the catheter 40 includes two catheter members, a tube 45 to which the first electrode group 41 is attached, and a tube 46 to which the second electrode group 42 is attached. The present invention does not limit the shape of the catheter, and as shown in Fig. 7, the catheter may be configured such that the first electrode group 41 and the second electrode group 42, as well as the first tip 43 and the second tip 44, are arranged on a single tube 47 made of an insulator. Even with such a configuration, it is possible to obtain the same technical effects as those described in the above embodiment by arranging the first electrode group 41 in the coronary vein and the second electrode group 42 near the right atrium.

[0064] <Variation 2> In the above embodiment, it is also possible to configure the electrocardiograph device 101 to be incorporated inside the atrial fibrillation defibrillation system. In this case, as shown in Modification 2 in Fig. 8, this can be realized by adding a band limiting and an amplification circuit for acquiring an intracardiac electrocardiogram signal to the electrocardiogram acquisition circuit 23, instead of acquiring an electrocardiogram waveform from electrodes placed on the body surface via the electrocardiograph device 101.

[0065] <Modification 3> In the above-described embodiment, it is also possible to detect an intracardiac electrocardiogram waveform and incorporate it into the atrial fibrillation defibrillation system without using the pacing function of the electrocardiograph device 101 or the IEGM device 102. In this case, as shown in Modification 3 in Fig. 9, in order to detect an intracardiac electrocardiogram signal from the first chip 43 or the second chip 44, it is possible to realize it by switching the switching elements 32, 33 to the connection on the terminal a side and inputting it to the electrocardiogram acquisition circuit 23. In addition, when pacing is performed after defibrillation, it is realized by switching the switching elements 32, 33 to the connection on the terminal b side and outputting a pacing pulse from the control circuit 24.

[0066] The above-mentioned embodiment and modified examples are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. Furthermore, the present invention may be modified or improved without departing from the spirit of the present invention, and it goes without saying that the present invention includes equivalents thereof. [Explanation of symbols]

[0067] Electrocardiograph device 21, IEGM device 22, electrocardiogram acquisition circuit 23, control circuit 24, charge circuit 11, charge / discharge capacitor 12, pulse generation circuit 13, impedance detection circuit 25, switching elements 31 to 35, first chip 43, second chip 44, first electrode group 41, second electrode group 42

Claims

1. A receiver for receiving an electrocardiogram signal; A control unit, The control unit is A process of sampling the electrocardiogram signal from the receiving unit at a constant frequency to obtain a sampling value; a calculation process for calculating a slope of an R wave in the electrocardiogram signal using the sampled values; A period detection process for detecting the period of the R wave; When the disturbance of the cycle is detected, it is determined that the atrial fibrillation occurs, and a defibrillation process is executed to defibrillate the atrium. In the calculation process, A process of detecting a fall time of the R wave based on the sampled value; comparing the fall time to a first normal range; When the positive and negative of the slope are inverted and the falling time is within the first normal range, a peak detection process is executed to detect a peak of the R wave based on the sampled value. Atrial Fibrillation Defibrillation System.

2. The control unit is In the calculation process, further performing a process of comparing the slope with a predetermined range; The atrial defibrillation system of claim 1 , further comprising: a peak detection process that is performed if the slope is within the predetermined range.

3. The control unit is In the calculation process, A process of detecting a rise time of the R wave based on the sampled value; comparing the rise time to a second normal range; 3. The atrial defibrillation defibrillation system according to claim 1, further comprising: a peak detection process that executes the peak detection process when the rise time is within the second normal range.

4. The constant frequency is the Na ＋ 4. The atrial defibrillation defibrillation system according to claim 1, wherein the response time of the channel is taken into consideration.

5. A defibrillation catheter is further provided which is inserted into the heart chamber to perform defibrillation of atrial fibrillation. The control unit is The cycle detection process includes a process of calculating a peak cycle, which is a cycle at which a peak of the R wave occurs, the defibrillation process includes a process of not performing defibrillation when the peak period is constant, and performing the defibrillation using the defibrillation catheter when the peak period of the R wave varies.

5. An atrial defibrillation system according to claim 1.

6. The control unit, in the defibrillation process, performing said defibrillation within the absolute refractory period; 6. An atrial defibrillation system as claimed in claim 5.

7. The control unit, in the defibrillation process, The defibrillation is performed at a timing when the absolute refractory period is shortened and the R wave changes from a rising edge to a falling edge.

7. An atrial fibrillation defibrillation system according to claim 5 or 6.

8. the defibrillation catheter includes an electrode for applying a pacing pulse; The control unit, after the defibrillation process, applying pacing pulses into the heart chamber via the electrodes, the pacing pulses corresponding to a normal heart rate; 8. An atrial defibrillation system according to any one of claims 5 to 7.

9. The defibrillation catheter has an insulating tube member and an electrode group composed of a plurality of ring-shaped electrodes attached to the tube member, the electrode group includes a first electrode group arranged in the coronary sinus of the heart, a second electrode group arranged in the right atrium, the right atrial appendage, or the base of the superior vena cava of the heart, and a pacing-only electrode; 9. An atrial defibrillation system according to any one of claims 5 to 8.

10. a charging circuit for charging a defibrillation voltage; a capacitor electrically insulated from the charging circuit and configured to charge and discharge the defibrillation voltage; a power supply device further including a pulse generating circuit that is electrically insulated from the control unit and outputs a pulse to the electrode group, thereby electrically insulating the control unit and the charge circuit so that noise generated from the pulse generating circuit is not transmitted to the control unit and the charge circuit.

10. The atrial defibrillation system of claim 9.

11. A process of sampling the electrocardiogram signal at a constant frequency to obtain a sampling value; a calculation process for calculating a slope of an R wave in the electrocardiogram signal using the sampled value; In the calculation process, A process of detecting a fall time of the R wave based on the sampled value; and further causing the control unit to execute a process of comparing the fall time with a normal range. When the fall time is within the normal range, the control unit executes a peak detection process to detect a peak of the R wave based on a sampling position immediately before a sampling position when the slope is continuously obtained and the polarity of the slope is inverted. program.

12. 11. An atrial fibrillation defibrillation system as described in any one of claims 1 to 10, characterized in that an intracardiac electrocardiogram waveform is directly detected using a first tip or a second tip provided at the tip of a defibrillation catheter without using an electrocardiogram signal obtained from outside the body, thereby detecting the R wave from the intracardiac electrocardiogram waveform without using an electrocardiogram signal from the surface of the body.

13. 13. An atrial fibrillation defibrillation system as claimed in claim 12, characterized in that the control unit outputs pacing pulses without using the pacing output of an IEGM device, thereby enabling the timing of pacing to be optimized by the control circuit of the system.

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