阅读说明：本技术 植入医疗设备和室颤计数方法 (Implanted medical device and ventricular fibrillation counting method ) 是由 洪峰 平利川 于 2019-12-16 设计创作，主要内容包括：本发明提供一种植入式医疗设备的室颤技术方案和植入式医疗设备,植入式医疗设备包：括连接心肌组织与所述感测电路,向所述感测电路传递心电信号的导线；执行电路,被配置为进行室颤计数。所述室颤计数包括：获取当前实时心率；根据所述实时心率更新实时心率数据序列；根据所述心率数据序列计算室颤计数值,所述室颤计数值为实时心率数据序列中大于快室速门限的个数。(The invention provides a ventricular fibrillation technical scheme of an implanted medical device and the implanted medical device, wherein the implanted medical device comprises: the lead is used for connecting myocardial tissue and the sensing circuit and transmitting electrocardiosignals to the sensing circuit; an execution circuit configured to perform ventricular fibrillation counting. The ventricular fibrillation count comprises: acquiring a current real-time heart rate; updating a real-time heart rate data sequence according to the real-time heart rate; and calculating a ventricular fibrillation count value according to the heart rate data sequence, wherein the ventricular fibrillation count value is the number of the real-time heart rate data sequence which is larger than the fast ventricular rate threshold.)

1. A method of implanted medical device ventricular fibrillation counting, wherein the implanted medical device comprises:

acquiring a current real-time heart rate;

updating a real-time heart rate data sequence according to the real-time heart rate;

and calculating a ventricular fibrillation count value according to the heart rate data sequence, wherein the ventricular fibrillation count value is the number of the real-time heart rate data sequence which is larger than the fast ventricular rate threshold.

2. The method of implanted medical device ventricular fibrillation count of claim 1, wherein the real-time heart rate sequence is stored in a shift register, the shift register performing a shift after acquiring a real-time heart rate.

3. The method of implanted medical device ventricular fibrillation count of claim 2, wherein the real-time heart rate data sequence is 24 bits in length.

4. The method of claim 1, wherein the fast ventricular rate threshold is a value in the range of 140-.

5. An implantable medical device, characterized in that the implantable medical device comprises:

sensing circuitry for sensing the cardiac electrical signal;

a lead for connecting the myocardial tissue to the sensing circuit and transmitting the electrocardiosignal to the sensing circuit;

execution circuitry configured to:

acquiring a current real-time heart rate;

updating a real-time heart rate data sequence according to the real-time heart rate;

calculating a ventricular fibrillation count value according to the real-time heart rate data sequence, wherein the ventricular fibrillation count value is the number of the real-time heart rate data sequence which is larger than a ventricular speed threshold;

and if the ventricular fibrillation count value reaches a first threshold value, performing ventricular fibrillation diagnosis.

6. The implantable medical device of claim 5, wherein the ventricular fibrillation diagnosis further comprises:

judging whether a ventricular fibrillation area value exists in a heart rate backtracking window or not; ventricular fibrillation is determined if the value of the ventricular fibrillation region exists, and ventricular tachycardias is determined if the value of the ventricular fibrillation region does not exist.

7. An implantable medical device, comprising:

sensing circuitry for sensing the cardiac electrical signal;

a lead for connecting the myocardial tissue to the sensing circuit and transmitting the electrocardiosignal to the sensing circuit;

the execution circuitry is configured to:

acquiring a current real-time heart rate;

updating a ventricular fibrillation count and a ventricular rate count based on the real-time heart rate, the ventricular fibrillation count comprising:

updating the real-time heart rate data sequence according to the real-time heart rate roll; calculating a ventricular fibrillation count value according to the real-time heart rate data sequence, wherein the ventricular fibrillation count value is the number which is larger than a fast ventricular rate threshold in the real-time heart rate data sequence;

and if the ventricular fibrillation count reaches a first threshold, updating a combined count, wherein the combined count is the algebraic sum of the ventricular speed count and the ventricular fibrillation count.

8. An implantable medical device, comprising:

sensing circuitry for sensing the cardiac electrical signal;

a lead for connecting the myocardial tissue to the sensing circuit and transmitting the electrocardiosignal to the sensing circuit;

execution circuitry configured to execute:

acquiring a current real-time heart rate;

updating a ventricular fibrillation count and a ventricular rate count based on the real-time heart rate, the ventricular fibrillation count comprising: updating a real-time heart rate data sequence according to the real-time heart rate roll; calculating a ventricular fibrillation count value according to the real-time heart rate data sequence, wherein the ventricular fibrillation count value is the number which is larger than a fast ventricular rate threshold in the real-time heart rate data sequence;

if the ventricular fibrillation count reaches a first threshold, updating a combined count, wherein the combined count is the sum of the ventricular velocity count and the ventricular fibrillation count;

and if the combined counter reaches a second threshold, performing arrhythmia diagnosis, wherein the arrhythmia diagnosis comprises: judging whether a ventricular fibrillation area value exists in a heart rate backtracking window or not; if the value of the ventricular fibrillation area exists, judging that the ventricular fibrillation area exists; if not, judging the chamber speed;

and judging whether the value of the fast ventricular rate region exists in the heart rate backtracking window or not, if so, judging the value to be fast ventricular rate, and otherwise, judging the value to be ventricular rate.

Technical Field

The invention belongs to the field of medical equipment, and particularly relates to improvement of implantable medical equipment for heart diseases.

Background

Such as Implantable Cardiac Defibrillators (ICDs) or Implantable Cardiac Monitors (ICMs) or cardiac pacemakers (cardiac pacemakers), which monitor cardiac electrical signals to diagnose cardiac conditions and provide therapy. One typical method is to determine whether ventricular tachycardia or ventricular fibrillation exists by real-time heart rate counting, and perform treatment according to the determination result.

Disclosure of Invention

It is an object of the present invention to provide a method of ventricular fibrillation counting for use in an implantable medical device comprising:

sensing circuitry for sensing the cardiac electrical signal;

a lead for connecting the myocardial tissue to the sensing circuit and transmitting the electrocardiosignal to the sensing circuit;

execution circuitry configured to:

acquiring a current real-time heart rate;

updating a real-time heart rate data sequence according to the real-time heart rate;

and calculating a ventricular fibrillation count value according to the heart rate data sequence, wherein the ventricular fibrillation count value is the number of the real-time heart rate data sequence which is larger than the fast ventricular rate threshold.

The counting method converts a plurality of real-time heart rates into a data sequence, counts the number of the heart rates greater than the fast ventricular rate in the data sequence to serve as counting data of ventricular fibrillation, and can reflect heartbeat data within a period of time.

In a preferred embodiment, in the method for counting ventricular fibrillation of an implanted medical device, the length of the real-time heart rate data sequence is 24 bits.

In a preferred solution, the real-time heart rate sequence is stored in a shift register, which performs a shift after the real-time heart rate has been acquired.

In a preferred embodiment, the ventricular fibrillation threshold is a value in the range of 140-250 bpm.

The second purpose of the invention is to provide an implantable medical device, which calculates ventricular fibrillation count values according to the real-time heart rate data sequence, wherein the ventricular fibrillation count values are the number of the real-time heart rate data sequence which is larger than a ventricular rate threshold; and if the ventricular fibrillation count value reaches a first threshold value, performing ventricular fibrillation diagnosis.

In the preferred scheme, judging whether a ventricular fibrillation zone value exists in a heart rate backtracking window; ventricular fibrillation is determined if the value of the ventricular fibrillation region exists, and ventricular tachycardias is determined if the value of the ventricular fibrillation region does not exist.

The backtracking window is the last specific heartbeats at the tail part of the real-time heart rate sequence, the heartbeats in the backtracking window reflect the heartbeat condition of a period of time before the real-time heartbeat of the patient, and the backtracking window is adopted to judge whether the ventricular fibrillation exists or not, so that the diagnosis precision can be improved.

It is a further object of the present invention to provide a method for joint counting of cardiac events, including ventricular rate events and ventricular fibrillation events, in an implantable medical device. The count of the cardiac combination counter is the algebraic sum of the ventricular fibrillation count and the ventricular velocity count.

Specifically, the joint counting method comprises the following steps:

acquiring a current real-time heart rate;

updating a ventricular fibrillation count and a ventricular rate count based on the real-time heart rate, the ventricular fibrillation count comprising the steps of: updating the real-time heart rate data sequence according to the real-time heart rate roll; calculating a ventricular fibrillation count value according to the real-time heart rate data sequence, wherein the ventricular fibrillation count value is the number which is larger than a fast ventricular rate threshold in the real-time heart rate data sequence;

and if the ventricular fibrillation count reaches a first threshold, updating a combined count, wherein the combined count is the algebraic sum of the ventricular speed count and the ventricular fibrillation count.

The combined use of the sum of ventricular fibrillation and ventricular rate prevents the heart rate from failing to reach the threshold for triggering diagnosis or treatment by relying only on ventricular fibrillation or ventricular rate counting when the heart rate fluctuates off the threshold boundary of ventricular fibrillation and ventricular rate.

The fourth objective of the present invention is to provide an implantable medical device for diagnosing arrhythmia using a combined counting method,

the implanted medical device is configured to: and performing arrhythmia diagnosis when the joint counter reaches a second threshold, wherein the arrhythmia diagnosis comprises: :

judging whether a ventricular fibrillation area value exists in a heart rate backtracking window or not; if the value of the ventricular fibrillation area exists, judging that the ventricular fibrillation area exists; if not, judging the chamber speed;

and judging whether the value of the fast ventricular rate region exists in the heart rate backtracking window, judging the fast ventricular rate in the fast ventricular rate region value, and otherwise, judging the fast ventricular rate.

Drawings

Fig. 1 is a schematic view of an implantable medical device.

Fig. 2 is a schematic diagram of a ventricular fibrillation counting process of the implantable medical device.

Fig. 3 is a schematic diagram of a logic structure of a real-time heart rate data sequence.

Fig. 4 is a schematic diagram of a ventricular fibrillation diagnosis process of the implantable medical device.

Fig. 5 is a schematic view of a joint counting process of an implantable medical device.

Fig. 6 is a flow chart of chamber velocity counting used in combination counting of implantable medical devices.

Fig. 7 is a flow chart of an implantable medical device utilizing joint counting for arrhythmia diagnosis.

Detailed Description

Implantable medical devices referred to herein are cardiac medical devices including, but not limited to, Implantable Cardiac Defibrillators (ICDs), Implantable Cardiac Monitors (ICMs), implantable cardiac pacemakers (lead leadless defibrillators), leadless implantable cardiac defibrillators, Subcutaneous Implantable Cardiac Defibrillators (SICDs). The implanted medical equipment can sense electrocardiosignals, diagnose heart diseases of patients according to the electrocardiosignals and store key heart data. The ICD and the pacemaker can also provide defibrillation \ pacing and other treatments according to the diagnosis result.

The invention takes an Implanted Cardiac Defibrillator (ICD) as an example to explain a counting method of ventricular fibrillation (ventricular fibrillation for short), a counting method of ventricular tachycardia (ventricular tachycardia for short), a combined counting method and a corresponding diagnosis method. It is obvious that those skilled in the art can easily apply these methods to implantable cardiac medical devices such as implantable cardiac pacemakers/implantable cardiac monitors.

ICD Overall Structure

FIG. 1 shows the internal structural modules of ICD104, and where it is implanted on the posterior leads and electrodes of the human heart. The ICD includes a body portion 104 and a lead 105 connected to the ICD. The body portion is formed of a metal housing 102, and a connector 106 disposed on the metal housing, the connector 106 for electrically connecting the ICD hybrid circuit 108 and the lead. The metal housing 102 is typically a biocompatible titanium metal housing, and the ICD hybrid circuit is disposed inside the metal housing 102. ICD lead 105 is used to connect cardiac tissue 116 to ICD hybrid 108 and the ICD is used to deliver cardiac electrical signals to the hybrid 108. While the ICD delivers therapy including pacing, defibrillation, anti-tachycardia pacing, etc. through the hybrid circuit 108.

ICD hybrid circuit

The ICD hybrid 108 includes a sensing unit 110, an execution unit 114, a therapy unit 112, and a communication unit 126. The sensing unit 110 is configured to receive an electrocardiographic signal transmitted through the wire 105, the sensing unit 119 includes a signal processing circuit, and the electrocardiographic signal passes through an amplifying module, a filtering module, and an ADC conversion module, and finally forms a digital signal which can be read and processed by the execution unit 114. The sensing unit 110 may include any other known signal processing method besides signal processing, for example, the filtering module may include a digital filtering unit, and the sensing unit may also be an ASIC.

Hybrid circuit therapy unit

The therapy unit 112 includes a charge and discharge control circuit and a capacitor. The charge and discharge control circuit charges the circuit in the ICD battery into the capacitor through the transformer, and the discharge control circuit releases the electric energy in the capacitor into the myocardial tissue 116 through the lead 106. The pacing therapy delivers energy in the range of approximately 0.25 muj to 6 muj and the defibrillation in the range of approximately 20J to 40J, which is capable of restoring sinus rhythm in patients with ventricular tachycardia or ventricular fibrillation, etc.

Hybrid circuit communication unit

The communication unit 126 includes circuitry and an antenna for communicating with the ICD programmer or other recorder or remote follow-up device, and the communication unit 126 is for communicating with the ICD programmer or other recorder or remote follow-up device. The ICD program-controlled instrument is the equipment that the doctor used when diagnosing, and program-controlled instrument possesses display and input device, and the doctor can look over the heart electrograph that the ICD perceived on program-controlled instrument, looks over the parameter of ICD. These parameters include perceptual parameters, diagnostic parameters, or therapeutic parameters, among others. The ICD communicates with the programmer through known wireless communication techniques including, but not limited to, NFC near field communication, bluetooth communication, wireless local area network technology, or ultrasound communication, among others. The electrocardiogram, sensing parameters, diagnostic parameters and the like are transmitted between the ICD and the program-controlled instrument in data packets through the communication protocol.

Hybrid circuit execution unit

The ICD execution unit 114 is an execution circuit disposed on the ICD hybrid 108 that includes, but is not limited to, a special purpose processor, a general purpose processor, an ASIC (application specific integrated circuit), a CPLD (complex programmable logic device), or an FPGA (field programmable logic array), typically a processor chip. In the preferred scheme, the processor chip is an MCU singlechip, and the processor chip internally comprises a storage circuit which is used for storing a QRS waveform template. Besides the diagnosis function, the execution unit can also complete signal sensing, ventricular fibrillation diagnosis and treatment. The above-mentioned functions may also be realized by a computer instruction code, and the computer instruction code is obtained by compiling and burning a source program into a storage circuit of the MCU. It is noted that the memory circuit in the MCU is not essential and the memory circuit may also be stored in a separate module. The MCU communicates with the memory module via reserved pins that are typically used to connect to the bus of the ICD hybrid. Including but not limited to an address bus, a communication bus, and a control bus. In the present invention, the storage circuit is also used to store a patient QRS waveform template for SVT matching.

The execution unit is used for realizing all functions of the ICD, including but not limited to electrocardiosignal sensing, transceiving of communication data, diagnosis and treatment. The execution unit controls the sensing unit 110, the communication unit 126, the treatment unit 112 and the like to cooperatively work so as to realize diagnosis, treatment, data or state report on the patient, receive prescription parameters set by a doctor on the ICD program controller and transmit data to the program controller.

Algorithm ensemble

The machine code stored in memory includes methods that may enable ventricular fibrillation counting, methods that utilize the joint counting of ventricular fibrillation counts in combination with ventricular rate counts. It is noted that the memory unit in the ICD may store one or more of the above-described methods and the execution unit is configured to execute one or more of the above-described methods, i.e. the ICD programmer may be able to perform different types of counting or diagnostics simultaneously.

These algorithms are described below in conjunction with fig. 2-6, respectively.

Method for counting ventricular fibrillation

Referring to fig. 2 and 3, the method of ventricular fibrillation counting comprises the steps of:

202 obtaining a current real-time heart rate;

204 updating a real-time heart rate data sequence 300 according to the real-time heart rate;

206 calculate a ventricular fibrillation count value based on the heart rate data sequence, the ventricular fibrillation count value being the number greater than the fast ventricular rate threshold in the real-time heart rate data sequence.

In the process 202, the real-time heart rate is the heart rate x (n) of the last beat of the electrocardiographic signal sensed by the sensing unit. Where the x (n) function represents the calculation of the real-time heart rate, a typical real-time heart rate calculation, obtained by calculation of the time interval between the last (n beats) and the previous (n-1 beats). During specific execution, when the real-time heart rate is determined, the execution unit searches the position of the R wave peak of the last hop, then searches the position of the previous R wave peak, calculates the interval between the two R wave peaks, and determines the time t used by the hop, wherein the real-time heart rate is 1/t (the unit of t is second) or 1000/t (the unit of t is millisecond).

The real-time heart rate is stored as a data sequence 300 in said process 204 with reference to fig. 3. Typically the data sequence is 10-24 in length, i.e. the real-time heart rate values for the last 24 beats are stored as x (n-23), x (n-22), x (n-21). The data sequence may be represented as an array in the source program, i.e. in a continuous address space in the MCU memory, and the data storage sequence may also be a shift register, where the shift register shifts out the first data in the data sequence each time the real-time heart rate is stored in the last bit of the sequence of real-time heart rates, i.e. the new real-time heart rate data sequence is x (n-22), x (n-21), x (n-20).... times.x (n-1), x (n + 1).

The number of real-time heart rates greater than the fast ventricular rate threshold is counted as the ventricular fibrillation count in the process 206. Whether each jump in the real-time heart rate data sequence belongs to ventricular fibrillation is obtained by comparing the heart rate with a fast ventricular rate threshold. The value of the ventricular fibrillation count is stored in block 206 using the variable y, and it is apparent that the sequence of real-time heart rate data changes every beat, so that the value of the ventricular fibrillation count y may change after each count of ventricular fibrillation counts.

The ventricular rate threshold is a threshold value of the non-treatment heart rate zone and the ventricular rate zone, and the fast ventricular rate threshold is a threshold value of the slow ventricular rate zone and the fast ventricular rate zone. In the ICD algorithm the heart rate of the patient is divided into, in order of small arrival, a slow ventricular rate region, a ventricular rate region, and a ventricular fibrillation region. Preferably, the ventricular rate threshold value range is 90-200bpm, the rapid ventricular rate threshold value range is 140-250bpm, and the ventricular fibrillation threshold value range is greater than 250 bpm. Assuming that the slow ventricular speed threshold value is 150bpm, the fast ventricular speed threshold value is 200bpm, and the ventricular fibrillation threshold value is 250 bpm; then the real-time heart rate is considered as a non-treatment-needed heart rate if x (n) <150bpm, as being in the ventricular rate zone if the real-time heart rate is 150 ≦ x (n) <200bpm, as being in the fast ventricular rate zone if the real-time heart rate is 200 ≦ x (n) <250, and as being in the ventricular fibrillation zone if the real-time heart rate is x (n) > 250. The fast-room speed threshold may be different for different patients. The specific threshold value requires the doctor to set in the prescription parameters of the programmer according to the patient's condition.

Referring to fig. 4, a flow of ventricular fibrillation diagnosis by the implantable medical device using the ventricular fibrillation count is shown on the basis of fig. 2, and an execution unit of the implantable medical device is configured to implement the functions of the flow in fig. 4.

Wherein the processes 402-406 are the same as the 202-206 process in fig. 2, and the process 402-406 is performed. Process 408 performs a ventricular fibrillation diagnostic process 410 if the ventricular fibrillation count value reaches a threshold t 0.

In the process 408, the threshold t0 is set to 18, and it is obvious that the counter skilled in the art can adjust the threshold t0 according to the technical knowledge held by the counter.

The ventricular fibrillation diagnosis: including a value 410 to determine whether a ventricular fibrillation region exists in a heart rate backtracking window; ventricular fibrillation is determined if the value of the ventricular fibrillation region exists, and ventricular tachycardias is determined if the value of the ventricular fibrillation region does not exist.

Referring to fig. 3, the backtracking window W refers to a real-time heart rate value a certain amount ahead from the last real-time heartbeat. For example, if the backtracking window size is set to 8, the backtracking windows are x (n-7),.. x (n-1), x (n). In the process 410, if a real-time heart rate value of a ventricular fibrillation region (for example, a heart rate greater than 250 bpm) exists in the 8 heart rates, the ventricular fibrillation region is diagnosed, and if the real-time heart rate value of the ventricular fibrillation region does not exist, the ventricular tachycardia region is diagnosed. The execution unit controls the treatment to select an appropriate treatment mode according to the diagnosis result.

The backtracking window W is used for confirming the heartbeat condition of the patient in the past period of time and preventing the heart rate of the patient from being recovered by self to generate error treatment. It is clear that the size of the backtracking window can be adjusted, but the backtracking window cannot exceed the length of the real-time heart rate data sequence 300.

Joint counting method ensemble

Referring to fig. 5, a method of combined counting is shown that combines the above-described method of defibrillation counting and the method of ventricular rate counting and adds the defibrillation counting and the ventricular rate counting to obtain a combined count, which is relative to ventricular fibrillation or ventricular rate counting, that converges rapidly as the real-time heart rate fluctuates between ventricular and fast ventricular rates.

Combined counting method

Method for joint counting of cardiac events, comprising a procedure

502 obtaining a current real-time heart rate;

updating a ventricular fibrillation count and a ventricular rate count according to the real-time heart rate, the ventricular fibrillation count comprising the steps of: updating the real-time heart rate data sequence according to the real-time heart rate roll; calculating a ventricular fibrillation count value according to the real-time heart rate data sequence, wherein the ventricular fibrillation count value is the number which is larger than a fast ventricular rate threshold in the real-time heart rate data sequence;

if the ventricular fibrillation count reaches the first threshold t1, flow 508 is executed to update the joint count, which is the algebraic sum of the ventricular rate count and the ventricular fibrillation count.

Wherein the process 502 is the same as the process used in the process 202 of fig. 2. The process 504 updates the ventricular fibrillation counter in the same manner as the processes 204 and 206 of fig. 2, in process 506 the joint counter, i.e., the ventricular fibrillation count, is updated to 18 only when the speed of the ventricular fibrillation counter reaches a first threshold t1, preferably 18, and if the joint counter is not reached, the process returns to the process 102 of acquiring the real-time heart rate. It is noted that the ventricular fibrillation and ventricular rate counts are counted independently using the same real-time heart rate x (n) data, with the values of ventricular fibrillation and ventricular rate counts being stored in different variable values, respectively.

Chamber velocity counting method in combined counting method

The method for chamber velocity counting described with reference to fig. 6 further comprises the steps of:

602 obtains a real-time heart rate, which is equivalent to the process 102 in fig. 5, and both of them may be one process.

604 when the real-time heart rate is less than the room speed threshold, clearing the room speed count;

606 when the real-time heart rate is larger than the room speed threshold and smaller than the fast room door limit, counting is automatically increased;

the chamber speed counter counts a constant number of times greater than a fast chamber speed threshold.

The chamber speed threshold is preferably one of 90 to 200bpm, for example 150 bpm;

taking the above-mentioned room speed threshold of 150bpm and the fast room speed threshold of 200bpm as an example, in the process 604, when the real-time heart rate is smaller than the room speed threshold of 150bpm, the real-time heart rate is considered to be the normal heart rate, and therefore, the real-time heart rate is not counted as the room speed heart rate. If not, flow 606 is entered.

When the real-time heart rate is less than the fast chamber speed threshold 200 in the process 606, the chamber speed count value is incremented by 1, i.e., the process 608 is executed.

In process 606, when a value greater than the fast chamber speed threshold 200 occurs, it is considered to be outside the range of chamber speeds into the range of ventricular fibrillation or fast-hourly counts.

As can be seen from the above flow of combined counting and ventricular rate counting, the real-time heart rate counts the ventricular rate in the ventricular rate region, and if the real-time heart rate exceeds the limit of the ventricular rate region, the ventricular fibrillation counting is performed while the ventricular rate counting is suspended. Meanwhile, the value of the combined counting is the algebraic sum of the real-time heart rate and the ventricular fibrillation, so that the real-time heart rate can be normally calculated by the combined counting no matter whether the real-time heart rate is ventricular fibrillation or ventricular velocity, and the problem of slow fluctuation convergence of the real-time heart rate on the upper and lower ventricular velocity and the ventricular fibrillation threshold can be solved.

Referring to fig. 7, a diagnosis method of the implantable medical device based on the joint counting method is illustrated, and an execution unit of the implantable medical device is configured to implement all functions in the flow chart shown in fig. 7.

The flow 702-708 is the same as the flow 504-508 in fig. 5.

The count value of the joint count is obtained after the joint count is updated after the flow 708 is executed, i.e., after the flow 710 is reached.

In the process 710, if the combined count reaches a second threshold t2, arrhythmia diagnosis is performed. The second threshold t2 is preferably 21 when a heart rate data sequence length of 24 is implemented.

The arrhythmia diagnosis comprises the following procedures:

the process 712 determines whether there is a value of ventricular fibrillation region in the heart rate backtracking window W; if the value of the ventricular fibrillation area exists, judging that the ventricular fibrillation area exists; if not, judging the chamber speed;

the process 714 determines whether the heart rate backtracking window W has a fast ventricular rate region value, and determines the fast ventricular rate in the fast ventricular rate region value, otherwise, the fast ventricular rate is the ventricular rate.

The backtracking window is the same as the backtracking window in fig. 3 in flows 712 and 714, and the role is the same.

One or more of these functions may be implemented in the implanted medical device, and the particular method of implementation may require a physician to set up the device using a programmer according to the patient's actual condition. Similarly, the parameters and data used in the algorithm can be set according to the program controller. The implantable heart monitor ICM may be provided with a ventricular rate counting algorithm, a fibrillation counting algorithm, a joint counting algorithm. The implantable cardiac defibrillator can also be matched with corresponding treatments such as pacing treatment, anti-tachycardia treatment, defibrillation treatment and the like on the basis of the algorithm.