阅读说明：本技术 一种具备计数和识别心室速率功能的植入式医疗设备 (Implantable medical device with functions of counting and identifying ventricular rate ) 是由 洪峰 平利川 于 2019-12-16 设计创作，主要内容包括：本发明描述了一种具备计数和识别心室速率的植入式医疗设备,根据心电信号进行心脏事件的计数和识别。所述植入式医疗设备通过计算机软件实现执行单元对心脏事件的计数和识别。所述植入式医疗设备包括植入式心脏除颤器(ICD)、植入式心脏监视器(ICM)、植入式心脏起搏器(Cardiac Pacemaker)、无导线植入心脏起搏器和皮下式植入心脏除颤器(SICD)。(An implantable medical device having a counter and an identification of ventricular rate is described for counting and identifying cardiac events from cardiac electrical signals. The implantable medical device implements counting and identification of cardiac events by the execution unit via computer software. The implantable medical devices include Implantable Cardiac Defibrillators (ICDs), Implantable Cardiac Monitors (ICMs), implantable Cardiac pacemakers (cardioc pacemakers), leadless implantable Cardiac pacemakers, and Subcutaneous Implantable Cardiac Defibrillators (SICDs).)

1. An implantable medical device with chamber rate counting functionality, the implantable medical device configured to:

step a, updating a real-time heart rate value according to an electrocardiosignal;

step b, updating the chamber speed counting value by a chamber speed counter;

the step b further comprises the following steps:

step b1, comparing the real-time heart rate value with a chamber rate threshold value, when the real-time heart rate value is smaller than the chamber rate threshold value, the chamber rate count value returns to zero and starts counting again;

step b2, when the real-time heart rate value is larger than or equal to the chamber speed threshold value and smaller than the rapid chamber speed threshold value, adding 1 to the chamber speed count value;

step b3 when the real-time heart rate value is greater than or equal to the fast chamber speed threshold value, the chamber speed counter does not count.

2. The implantable medical device of claim 1, wherein the chamber velocity threshold value is derived by: take some integer value in 150-.

3. The implantable medical device of claim 1, wherein the rapid chamber velocity threshold value is derived by: take 200 and 250 bpm.

4. An implantable medical device with chamber rate identification, the implantable medical device configured to:

step a, updating a real-time heart rate value according to an electrocardiosignal;

step b, updating the chamber speed counting value by a chamber speed counter;

the step b further comprises the following steps:

step b1, comparing the real-time heart rate value with a chamber rate threshold value, when the real-time heart rate value is smaller than the chamber rate threshold value, the chamber rate count value returns to zero and starts counting again;

step b2, when the real-time heart rate value is larger than or equal to the chamber speed threshold value and smaller than the rapid chamber speed threshold value, adding 1 to the chamber speed count value;

step b3, when the real-time heart rate value is larger than or equal to the fast chamber speed threshold value, the chamber speed counter does not count;

step b4 identifies chamber velocity when the chamber velocity count reaches a first threshold, otherwise, continues to update the real-time heart rate value.

5. The implantable medical device of claim 4, wherein the identification module is capable of inducing the corresponding therapy module.

6. The implantable medical device of claim 5, wherein the chamber velocity count value is added to the original chamber velocity count value and is counted when the chamber velocity count value is increased by 1 and does not reach the first threshold value.

7. The implantable medical device of claim 6, wherein the first threshold value is 6.

8. An implantable medical device having cardiac event counting functionality, the medical device configured to:

step a, updating a real-time heart rate value according to an electrocardiosignal;

step B, continuously updating a ventricular fibrillation count value according to the real-time heart rate value, wherein the ventricular fibrillation count value is equal to the number of the real-time heart rate values in the shift register which are larger than the quick ventricular speed threshold value;

step B1, when the ventricular fibrillation count value is smaller than the second threshold value, returning to the step a to continuously update the real-time heart rate value;

step B2 triggers the joint counter when the ventricular fibrillation count reaches the second threshold, and the joint counter updates the joint count, which is the ventricular speed count + the ventricular fibrillation count.

Step b, updating the chamber speed counting value by a chamber speed counter;

the step b further comprises the following steps:

step b1, comparing the real-time heart rate value with a chamber rate threshold value, when the real-time heart rate value is smaller than the chamber rate threshold value, the chamber rate count value returns to zero and starts counting again;

step b2, when the real-time heart rate value is larger than or equal to the chamber speed threshold value and smaller than the rapid chamber speed threshold value, adding 1 to the chamber speed count value;

step b3 when the real-time heart rate value is greater than or equal to the fast chamber speed threshold value, the chamber speed counter does not count.

9. The implantable medical device of claim 8, wherein the ventricular fibrillation count value is calculated by:

step a, updating a real-time heart rate value according to an electrocardiosignal;

step C, updating a shift register x (n-m +1), x (n-m), according to the real-time heart rate value;

and D, the ventricular fibrillation count value is equal to the number of real-time heart rate values larger than the quick ventricular rate threshold value in the shift register.

10. The implantable medical device of claim 9, wherein the shift register shifts once per updated real-time heart rate value.

11. The implantable medical device having cardiac event counting as claimed in claim 10, wherein the second threshold is equal to 6.

12. An implantable medical device with cardiac event recognition, the implantable medical device configured to:

step a, updating a real-time heart rate value according to an electrocardiosignal;

step C, updating a shift register x (n-m +1), x (n-m), according to the real-time heart rate value;

step B, continuously updating a ventricular fibrillation count value according to the real-time heart rate value, wherein the ventricular fibrillation count value is equal to the number of the real-time heart rate values in the shift register which are larger than the quick ventricular speed threshold value;

step B1, when the ventricular fibrillation count value is smaller than the second threshold value, returning to the step a to continuously update the real-time heart rate value;

step B2, when the ventricular fibrillation count value reaches the second threshold, triggering the joint counter, and updating the joint count value by the joint counter, where the joint count value is ventricular speed count value + ventricular fibrillation count value;

and D, when the combined count value reaches a third threshold value, starting a backtracking window, wherein the operation method of the backtracking window comprises the following steps:

and E, detecting whether a real-time heart rate value in the range of the ventricular fibrillation region exists in the backtracking window, if at least one implemented heart rate value in the range of the ventricular fibrillation region exists, identifying the heart event as ventricular fibrillation, if not, continuously identifying whether a real-time heart rate value in the range of the rapid ventricular rate region exists in the backtracking window, if at least one implemented heart rate value in the range of the rapid ventricular rate region exists, identifying the heart event as rapid ventricular rate, and if not, identifying the heart event as rapid ventricular rate, otherwise, identifying the heart event as ventricular rate.

13. The implantable medical device having cardiac event recognition as in claim 12, wherein the backtracking window comprises a unit length of 8.

14. The implantable medical device with cardiac event recognition as set forth in claim 13, wherein the third threshold value is 21.

Technical Field

The invention relates to implantable medical equipment, which can count and identify the type of a cardiac event or the type of a cardiac disease by monitoring a electrocardiosignal and is used for monitoring, identifying or treating the cardiac event or arrhythmia clinically.

Background

Implantable Cardioverter Defibrillators (ICDs), Implantable Cardiac Monitors (ICMs), cardiac pacemakers (cardiac pacemakers) or leadless implantable cardiac defibrillators and Subcutaneous Implantable Cardiac Defibrillators (SICDs) are important medical devices for clinically treating persistent or fatal ventricular arrhythmias.

Implantable cardioverter-defibrillators (ICDs) are an important clinical therapy for persistent or fatal ventricular arrhythmias, and have supportive, anti-tachycardia pacing, low-energy cardioversion, and high-energy defibrillation effects.

Currently, sensing of ventricular rate has become a state of the art technique, either by implanting a device carrying a sensing member inside the heart or by placing it outside the patient's body. Sensing signals inside the heart chambers includes heart sounds, rate, amplitude, frequency, period, etc.

When patients suffer from ventricular fibrillation, if treatment is not timely, the patients can miss the optimal treatment opportunity, and in severe cases, life risks can be caused. The ICD can identify a patient's tachyventricular arrhythmia within seconds and then automatically discharge defibrillation, which can significantly avoid the incidence of sudden death from malignant ventricular arrhythmias and thus avoid untimely treatment.

The heart disease is a general term of all heart diseases, but in the clinical process, the treatment of the heart disease needs to be specifically determined by combining the severity degree, the onset position and the like of the disease, and different treatment methods are needed for different kinds of heart diseases.

In order to accurately identify the kind of heart disease of a patient and achieve better treatment effect, it is clinically necessary to more finely classify the types of heart diseases, and this purpose is usually achieved in the identification process of heart diseases.

Currently, a typical method for identifying the type of heart disease 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

The invention provides a method for counting and judging the heart disease types in living organisms by the ventricular rate, which is suitable for the medical apparatus and clinical field.

Implantable medical devices are described that trigger counting and identification of ventricular rates through measurement of a patient's cardiac electrical signal. In some examples, triggering of these measurements may be done automatically (e.g., without a trigger input initiated from an external source, such as based on a request initiated from the patient or from an external device by a physician), and triggering the measurement of ventricular rate may occur within certain numerical ranges based at least in part on monitoring one or more physiological parameters associated with the patient.

The present invention provides a system including an Implantable Medical Device (IMD). The IMD system may include: communication circuitry configured to communicate with an external computing device, sensing circuitry configured to sense cardiac signals that vary according to a ventricular rate of a patient, and processing circuitry. The processing circuitry may be configured to: determining a series of consecutive cardiac disorder threshold ranges based on the sensed cardiac signal; and identifying a type of cardiac disease based on each of the different types of cardiac diseases threshold values. The processing circuitry may be further configured to: detecting a suspended episode of cardiac disease in the patient based on the sensed cardiac signals, and controlling the communication circuitry to transmit an indication of the detected suspended episode of cardiac disease to an external computing device.

The invention provides an implantable medical device with chamber velocity counting function, which is characterized in that the implantable medical device is configured to:

step a, updating a real-time heart rate value according to an electrocardiosignal;

step b, updating the chamber speed counting value by a chamber speed counter;

the step b further comprises the following steps:

step b1, comparing the real-time heart rate value with a chamber rate threshold value, when the real-time heart rate value is smaller than the chamber rate threshold value, the chamber rate count value returns to zero and starts counting again;

step b2, when the real-time heart rate value is larger than or equal to the chamber speed threshold value and smaller than the rapid chamber speed threshold value, adding 1 to the chamber speed count value;

step b3 when the real-time heart rate value is greater than or equal to the fast chamber speed threshold value, the chamber speed counter does not count.

The invention provides an implantable medical device with a chamber velocity recognition function, which is characterized in that the implantable medical device is configured to:

step a, updating a real-time heart rate value according to an electrocardiosignal;

step b, updating the chamber speed counting value by a chamber speed counter;

the step b further comprises the following steps:

step b1, comparing the real-time heart rate value with a chamber rate threshold value, when the real-time heart rate value is smaller than the chamber rate threshold value, the chamber rate count value returns to zero and starts counting again;

step b2, when the real-time heart rate value is larger than or equal to the chamber speed threshold value and smaller than the rapid chamber speed threshold value, adding 1 to the chamber speed count value;

step b3, when the real-time heart rate value is larger than or equal to the fast chamber speed threshold value, the chamber speed counter does not count;

step b4 identifies chamber velocity when the chamber velocity count reaches a first threshold, otherwise, continues to update the real-time heart rate value.

The identification module can induce the corresponding therapy module.

When the chamber speed counting value is increased by 1 and does not reach the first threshold value, the chamber speed counting value is overlapped and counted on the basis of the original chamber speed counting value.

The invention provides an implantable medical device with cardiac event counting, characterized in that the medical device is configured to:

step a, updating a real-time heart rate value according to an electrocardiosignal;

step B, continuously updating a ventricular fibrillation count value according to the real-time heart rate value, wherein the ventricular fibrillation count value is equal to the number of the real-time heart rate values in the shift register which are larger than the quick ventricular speed threshold value;

step B1, when the ventricular fibrillation count value is smaller than the second threshold value, returning to the step a to continuously update the real-time heart rate value;

step B2 triggers the joint counter when the ventricular fibrillation count reaches the second threshold, and the joint counter updates the joint count, which is the ventricular speed count + the ventricular fibrillation count.

Step b, updating the chamber speed counting value by a chamber speed counter;

the step b further comprises the following steps:

step b1, comparing the real-time heart rate value with a chamber rate threshold value, when the real-time heart rate value is smaller than the chamber rate threshold value, the chamber rate count value returns to zero and starts counting again;

step b2, when the real-time heart rate value is larger than or equal to the chamber speed threshold value and smaller than the rapid chamber speed threshold value, adding 1 to the chamber speed count value;

step b3 when the real-time heart rate value is greater than or equal to the fast chamber speed threshold value, the chamber speed counter does not count.

The calculation method of the ventricular fibrillation count value comprises the following steps:

step a, updating a real-time heart rate value according to an electrocardiosignal;

step C, updating a shift register x (n-m +1), x (n-m), according to the real-time heart rate value;

and D, the ventricular fibrillation count value is equal to the number of real-time heart rate values larger than the quick ventricular rate threshold value in the shift register.

The shift register shifts once every time the real-time heart rate value is updated.

The invention provides 12 an implantable medical device with cardiac event recognition, the implantable medical device configured to:

step a, updating a real-time heart rate value according to an electrocardiosignal;

step C, updating a shift register x (n-m +1), x (n-m), according to the real-time heart rate value;

step B, continuously updating a ventricular fibrillation count value according to the real-time heart rate value, wherein the ventricular fibrillation count value is equal to the number of the real-time heart rate values in the shift register which are larger than the quick ventricular speed threshold value;

step B1, when the ventricular fibrillation count value is smaller than the second threshold value, returning to the step a to continuously update the real-time heart rate value;

step B2, when the ventricular fibrillation count value reaches the second threshold, triggering the joint counter, and updating the joint count value by the joint counter, where the joint count value is ventricular speed count value + ventricular fibrillation count value;

and D, when the combined count value reaches a third threshold value, starting a backtracking window, wherein the operation method of the backtracking window comprises the following steps:

and E, detecting whether a real-time heart rate value in the range of the ventricular fibrillation region exists in the backtracking window, if at least one implemented heart rate value in the range of the ventricular fibrillation region exists, identifying the heart event as ventricular fibrillation, if not, continuously identifying whether a real-time heart rate value in the range of the rapid ventricular rate region exists in the backtracking window, if at least one implemented heart rate value in the range of the rapid ventricular rate region exists, identifying the heart event as rapid ventricular rate, and if not, identifying the heart event as rapid ventricular rate, otherwise, identifying the heart event as ventricular rate.

Drawings

FIG. 1 is a schematic diagram of an ICD configuration in an implantable medical device

FIG. 2 is a flow chart of a chamber velocity counting method for an implantable medical device

FIG. 3 is a flow chart of a chamber velocity identification method for an implantable medical device

FIG. 4 is a schematic diagram of a logical structure of a real-time heart rate value sequence of a backtracking window

FIG. 5 is a schematic diagram of a ventricular fibrillation counting process in the cardiac event counting method of the implantable medical device

FIG. 6 is a schematic diagram illustrating a ventricular fibrillation identification process in the implantable medical device cardiac event identification method

FIG. 7 is a flow chart of a method for counting cardiac events of an implantable medical device

FIG. 8 is a flow chart of a method for identifying cardiac events for an implantable medical device

Detailed Description

The figures and description provided herein illustrate and describe various examples of the inventive methods, apparatus and systems of the present disclosure. However, the methods, devices, and systems of the present disclosure are not limited to the specific examples as shown and described herein, and other examples and variations of the methods, devices, and systems of the present disclosure are considered within the scope of the present application, as will be understood by one of ordinary skill in the art.

The medical equipment applicable to the counting and identifying method comprises the following steps: implantable Cardiac Defibrillators (ICDs), Implantable Cardiac Monitors (ICMs), implantable Cardiac pacemakers (cardioc pacemakers), leadless implantable Cardiac pacemakers, and Subcutaneous Implantable Cardiac Defibrillators (SICDs). The identification of the chamber velocity event can be automatically achieved. Taking an implantable cardioverter-defibrillator (ICD) as an example, a ventricular rate (abbreviated as ventricular rate) counting method and a ventricular rate identification method corresponding thereto, a cardiac event joint counting method and a joint identification method corresponding thereto are described.

The medical device is configured to increment a counter value when a ventricular rate, a ventricular tachyarrhythmia event, and a ventricular fibrillation event are detected; the implantable medical device enables counting of cardiac events by an execution unit configured to subsequently transmit programming instructions from the execution circuitry to the implantable medical device. Cardiac events are counted and identified by sensing cardiac electrical signal parameters. The counting method is a computer program method realized by a program language, counting is part of identification, and identification is triggered by a corresponding counting result. According to the method, the counting and identification of the cardiac events are divided into three areas of ventricular velocity, rapid ventricular velocity and ventricular fibrillation according to the size of the real-time heart rate value, all the real-time heart rate values are covered by the three areas, and the real-time heart rate value is continuously increased according to the three areas of ventricular velocity, rapid ventricular velocity and ventricular fibrillation.

In the present invention, the notation "Y" in all flowcharts means "Yes", meaning "Yes", and the notation "N" means "No", meaning not Yes.

Fig. 1 is a schematic diagram of the external structure of an ICD100 and the relative positions of various components in the heart when the ICD is implanted inside the heart. The ICD includes a body structure formed of two parts, a body housing 105 and a connector 107 on the body housing, and a lead 115. The main body shell usually contains three parts of a power supply, a capacitor and a hybrid circuit, and the hybrid circuit is usually realized by coding a program through a chip. The exertion of ICD function can be realized through two kinds of modes, one kind is the inside automatic formula regulation and control of ICD organism, does not need artificial manual trigger and control, can realize automatically. Another way is to send the communication signal 185 through an external control device 190. the external control device 190 of the ICD is typically a programmable controller, a patient assistant, or other device capable of commanding or sensing its internal signal. The communication method 185 between the ICD and the external control device 190 may be one or more of wired communication, bluetooth, WIFI, LTE, CDMA, and other wireless communication networks. ICD lead 115 shown in FIG. 1 is a single lead, and may be a double lead, a triple lead, or a quadruple lead during clinical use, with the basic lead structure being similar to lead 115. Lead 115 is formed from coil 118 electrode 120A and electrode 120B, coil 118 being connected to the ICD subject via connector 107, the coil functioning as: the therapeutic purpose is achieved by discharging. Electrodes 120A and 120B sense signal parameters of cardiac events. Electrode 120B, also known as the coiled head, contains a coiled coil that, when in use, can be suspended from the other side of the lead and fixed to the tissue inside the heart, so that the electrode on the device can be more securely attached to the interior of the myocardium after the ICD is implanted in the heart of a human.

Fig. 2 is a flow chart illustrating a chamber velocity counting process of an implantable medical device. Firstly, step 202 updates a real-time heart rate value according to the electrocardiosignals, step 204 compares the real-time heart rate value with a chamber speed threshold value, if the real-time heart rate value is smaller than the chamber speed threshold value, a chamber speed counter is cleared and starts counting again, and the step 202 is returned to update the real-time heart rate value again; if the real-time heart rate value is greater than or equal to the chamber speed threshold value, then step 206 is performed to compare the real-time heart rate value with the rapid chamber speed threshold value, if the real-time heart rate value is less than the rapid chamber speed threshold value, the chamber speed count value is increased by 1, and the update of the chamber speed count value is completed by a chamber speed counter; if the real-time heart rate value is greater than or equal to the chamber rate threshold value, the chamber rate count value is not changed, i.e., the event is not counted, and the step 202 is returned to continue updating the real-time heart rate value. In the invention, the value range of the chamber speed threshold value is 150-.

Fig. 3 is a flow chart illustrating a ventricular rate identification process of an implantable medical device. The recognition of an event is triggered by a corresponding counting result. First, step 302 updates a real-time heart rate value based on the cardiac electrical signal. Then, step 304 compares the real-time heart rate value with a chamber rate threshold value, if the real-time heart rate value is smaller than the chamber rate threshold value, the chamber rate counter is cleared and starts counting again, and the step 302 is returned to update the real-time heart rate value again; if the real-time heart rate value is greater than or equal to the chamber speed threshold value, then step 306 is performed to compare the real-time heart rate value with the rapid chamber speed threshold value, if the real-time heart rate value is less than the rapid chamber speed threshold value, the chamber speed count value is increased by 1, and the update of the chamber speed count value is completed by a chamber speed counter; if the real-time heart rate value is greater than or equal to the chamber rate threshold value, the chamber rate count value is not changed, i.e., the event is not counted, and the step 302 is returned to continue updating the real-time heart rate value. When the chamber speed counting value is larger than the chamber speed threshold value and smaller than the quick chamber speed threshold value, the chamber speed counting event is an effective event, and the chamber speed counter triggers the counting step. With the continuous update of the real-time heart rate value, when the chamber speed counting value does not reach the first threshold value and meets the chamber speed counting condition, the chamber speed counting value is continuously overlapped and counted. When the chamber speed count reaches the first threshold, step 310, the chamber speed is identified. The first threshold value is 12.

Fig. 5 is a schematic diagram illustrating a ventricular fibrillation counting process in the cardiac event counting method of the implantable medical device. Firstly, a real-time heart rate value is continuously updated in step 502 through an electrocardiosignal, a shift register x (n-m +1), x (n-m +2),.., x (n) and n) is updated in step 504, and the real-time heart rate data sequence contained in the shift register in the ventricular fibrillation counting process is 24 bits, namely, the current real-time heart rate and the total 24 real-time heart rate data sequences from the current heart rate to the previous heart rate are updated each time. Step 506 represents a count condition for a ventricular fibrillation count value equal to the number of times greater than the ventricular rate threshold value in the sequence of 24-bit real-time heart rate values updated by the shift register.

Fig. 6 is a schematic diagram illustrating a flow of ventricular fibrillation recognition in the method for recognizing cardiac events of an implantable medical device. The population comprises two parts of updating the ventricular fibrillation counter and backtracking the judgment of the window ventricular fibrillation event. And in the first part, updating the ventricular fibrillation counter, and taking the real-time heart rate value higher than the rapid ventricular velocity region as a judgment basis of the ventricular fibrillation event. Firstly, step 602 updates the real-time heart rate value according to the electrocardiosignal, step 604 compares the real-time heart rate value with the rapid ventricular rate threshold value, and step 606 determines the ventricular fibrillation event count value according to the comparison result, wherein the ventricular fibrillation count value is the number of the real-time heart rate values in the shift register larger than the rapid ventricular rate threshold value, and the rapid ventricular rate threshold value takes the value of 200 + 250 bpm. And if the ventricular fibrillation count value reaches a third threshold value, starting judgment of ventricular fibrillation events in a second part of backtracking window, and if the ventricular fibrillation count value does not reach the third threshold value, returning to the step 602 to continuously update the real-time heart rate value. In fig. 6, the third threshold value is 18, that is, 18 real-time heart rate values out of 24 real-time heart rate values in the shift register are located in the ventricular fibrillation region, and when the ventricular fibrillation count value reaches the threshold value of 18, the backtracking window is started, and the heart rate value range of the ventricular fibrillation region is 200-. The sequence of real-time heart rate values within the backtracking window is updated according to step 610. step 610 compares all real-time heart rate values within said backtracking window with ventricular fibrillation region heart rate values, and if there is at least one real-time heart rate value within the ventricular fibrillation region, it is identified as ventricular fibrillation, otherwise, it is identified as fast ventricular speed.

Fig. 7 is a flow chart of a method for counting cardiac events of an implantable medical device. The method comprises two parts of judging the ventricular fibrillation condition and starting a joint counter. The first part performs a determination of ventricular fibrillation conditions based on the real-time heart rate values. First, step 702 updates a real-time heart rate value based on the cardiac electrical signal. Step 704 continuously updates the ventricular rate counter and the ventricular fibrillation counter based on the real-time heart rate values obtained at 702. The ventricular rate counter is updated by the method of counting ventricular rate count shown in fig. 2, and the ventricular fibrillation counter is updated by the method of counting ventricular fibrillation count shown in fig. 5. Step 706 compares the ventricular fibrillation count value to a second threshold and proceeds to a second section when the ventricular fibrillation count value reaches the second threshold. The second threshold value of the ventricular fibrillation counter is 6, and in actual operation, the second threshold value can be slightly modified according to actual requirements. Step 708 starts the joint counter, and step 710 counts a joint count value from the joint counter update, which is updated based on the ventricular rate counter and the ventricular fibrillation counter, and the joint count value is ventricular rate count value + ventricular fibrillation count value.

FIG. 4 is a schematic diagram of a logical structure of a real-time heart rate value sequence of a backtracking window. The backtracking window refers to several quantity units of the real-time heart rate, namely, the current real-time heart rate is traced forward by a certain quantity of real-time heart rate values. The number of the backtracking windows can be adjusted according to actual requirements, and the number unit of all backtracking windows is 8. And recording the real-time heart rate value as x (n), and then obtaining the backtracking windows as x (n-7), x (n-6), and x (n-1) and x (n). The real-time heart rate in the backtracking window is stored on the shift register, and the shift register shifts once every time the real-time heart rate value is updated. The shift register not only has the function of updating the real-time heart rate value, but also has the function of recording and storing the real-time heart rate value sequence, and can store all real-time heart rate value data sequences in the current backtracking window.

Fig. 8 is a flow chart of a method for identifying cardiac events of an implantable medical device. The method comprises three parts of judging the ventricular fibrillation condition, starting a joint counter and starting a backtracking window. The first part performs a determination of ventricular fibrillation conditions based on the real-time heart rate values. Step 802 updates the real-time heart rate value based on the cardiac electrical signal. Step 804 continuously updates the ventricular rate counter and the ventricular fibrillation counter based on the real-time heart rate values obtained 802. Step 806 compares the ventricular fibrillation count value to a second threshold and proceeds to a second section when the ventricular fibrillation count value reaches the second threshold. Step 808 starts the joint counter, step 810 compares the joint count value with a third threshold value, the joint count value is ventricular speed count value + ventricular fibrillation count value, if the joint count value does not reach the third threshold value, the step 804 returns to continue updating the ventricular fibrillation counter and the ventricular speed counter; if the joint count value reaches the third threshold, a backtracking window is initiated per step 812. The value of the joint count threshold T5 is 21. After the backtracking window is started, obtaining a real-time heart rate value sequence in the backtracking window according to fig. 4, and judging whether a ventricular fibrillation event exists in the backtracking window in step 814, namely judging whether a real-time heart rate value in a ventricular fibrillation region exists in the backtracking window, and if so, identifying the ventricular fibrillation event as ventricular fibrillation; if not, continuously judging whether a rapid room speed event exists in the backtracking window, namely judging whether a real-time heart rate value located in a rapid room speed area exists in the backtracking window, and if so, identifying the real-time heart rate value as the rapid room speed; otherwise, the chamber velocity is identified.

The algorithm can be used for calculating and identifying the heart internal ventricular rate by the implantable medical device. The two functions are realized in two ways, namely, the electrocardiosignal measurement and the cardiac event counting and identification are automatically completed; and secondly, manually regulating and controlling to complete the measurement of the electrocardiosignals and the counting and identification of the cardiac events. The second mode can be connected with a patient assistant, the sensed electrocardiosignal data are transmitted to the patient assistant, and the patient assistant is sent to the hospital for identification, so that the patient does not need to go to the hospital in person, and convenience is brought to the patient to a great extent. The medical device can also be connected with a remote device, and parameter setting and regulation and control are carried out on the medical device implanted in the body through the remote device.

The recognition result is divided into three areas, namely ventricular velocity, rapid ventricular velocity and ventricular fibrillation. The corresponding therapy modules are divided into three modules: a ventricular tachy therapy module, a rapid ventricular tachy therapy module and a ventricular fibrillation therapy module. The working state of the treatment (active/dormant) is determined by the outcome of the identification phase. After the current therapy module applies the therapy, the module monitors the patient's heart rate after the therapy and prepares for the next therapy. If the module finds that the treatment failed, it will continue to perform the next treatment until the patient's heartbeat returns to normal or the number of treatments reaches an upper limit.