A frequency adaptive pacing device based on qtci interval and acceleration sensor

Abstract

The application discloses a frequency adaptive pacing device based on QTc interval and acceleration sensor, which comprises a ventricular sensing module, a ventricular pacing module, a clock / timing module, a pacing control module, an acceleration sensor module, a motion information processing module and a data storage module; the motion information processing module updates the sensor indicated pacing interval based on the motion acceleration information collected by the acceleration sensor module; the pacing control module obtains historical event data from the data storage module to calculate the QTc interval after sensing the VS event through the ventricular sensing module or executing the VP event through the ventricular pacing module, calculates the QTc indicated pacing interval according to the QTc interval, selects the small interval between the sensor indicated pacing interval and the QTc indicated pacing interval as the final pacing interval, and realizes the frequency adaptive pacing. Thus, the QTc interval calculation and the acceleration sensor are combined to realize the frequency adaptive pacing.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, specifically relating to a frequency adaptive pacing device based on a QTc interval and acceleration sensor. Background Technology

[0002] Adaptive pacing is an important feature designed to ensure pacemaker patients receive sufficient cardiac output. For pacemaker-implanted patients who are engaged in daily activities, a single baseline pacing rate may not meet their metabolic needs. Adaptive pacing largely compensates for the symptoms of chronotropic cardiac dysfunction and greatly improves the exercise tolerance of pacemaker-implanted patients.

[0003] Currently, mainstream cardiac pacing devices use accelerometers to monitor the patient's activity level and dynamically adjust the pacing frequency to achieve adaptive pacing. Examples include a device and system for adaptive pacing frequency adjustment disclosed in patent application CN102526879A, and a sensor acquisition and processing system for an implantable cardiac pacemaker disclosed in patent application CN103495263A. However, this method of adaptive pacing based solely on accelerometers has drawbacks, including poor specificity and an inability to directly sense changes in the patient's metabolic processes (such as anxiety, fever, or diurnal variations in heart rhythm).

[0004] Some cardiac pacemakers use additional sensors to monitor patients' physiological parameters, such as closed-loop stimulation to measure intracardiac impedance during ventricular systole, or transthoracic impedance to monitor minute ventilation, enabling monitoring of metabolic changes and overcoming the limitations of accelerometer-based frequency-adaptive pacing. However, such frequency-adaptive pacing schemes require additional sensor hardware, increasing costs and lacking universality.

[0005] The interval between the QRS complex, representing ventricular cell depolarization, and the T wave, representing ventricular cell repolarization, in an electrocardiogram (ECG) is called the QT interval. The QT interval reflects the time interval between ventricular contraction and relaxation during a cardiac cycle. The QTc interval, corrected for heart rate, is an indicator of cardiac depolarization and repolarization. Multiple studies have shown that the length of the QTc interval is not only related to heart rate but also influenced by additional factors such as neural regulation. In patients with cardiac chronotropic disorders, changes in the QTc interval can also reflect changes in metabolic rate. Frequency-adaptive pacing protocols based on QTc interval measurement do not require additional sensors, but they suffer from problems such as insensitive sensing, long latency, and significant drug-induced interference. Summary of the Invention

[0006] In view of the above-mentioned technical problems, the purpose of this invention is to provide a frequency adaptive pacing device based on QTc interval and acceleration sensor, which integrates QTc interval calculation and acceleration sensor to achieve frequency adaptive pacing.

[0007] To achieve the above-mentioned objectives, the present invention provides a frequency adaptive pacing device based on QTc interval and acceleration sensor, comprising: a ventricular sensing module, a ventricular pacing module, a clock / timing module, a pacing control module, an acceleration sensor module, a motion information processing module, and a data storage module;

[0008] The operation information processing module updates the pacing interval indicated by the sensor based on the motion acceleration information collected by the acceleration sensor module.

[0009] After the pacing control module senses a VS event through the ventricular sensing module or executes a VP event through the ventricular pacing module, it retrieves historical event data from the data storage module to calculate the QTc interval, calculates the QTc indication pacing interval based on the QTc interval, and selects the smaller interval between the sensor indication pacing interval and the QTc indication pacing interval as the final pacing interval to achieve adaptive pacing.

[0010] Preferably, the step of obtaining historical event data from the data storage module to calculate the QTc interval includes:

[0011] Obtain the current pacing interval and the previous ventricular interval from historical event data, and calculate the VR-sensing interval using the following formula:

[0012]

[0013] Among them, the basic VR perception interval is a programmable parameter;

[0014] The pacing control module controls the ventricular sensing module to adjust the pacing threshold to the VR sensing threshold, and activates the sensing blank period and the VR sensing interval after the sensing blank period, and controls the ventricular sensing module to perform VR event sensing during the VR sensing interval.

[0015] The pacing control module calculates the QTc interval based on whether the ventricular sensing module senses the VR event within the VR sensing interval.

[0016] Preferably, the pacing control module calculates the QTc interval based on whether the ventricular sensing module senses the VR event within the VR sensing interval, including:

[0017] When a VR event is detected, the interval between the VS event and the VR event, or the interval between the VP event and the VR event, is taken as the QT interval, and the QTc interval is calculated based on the QT interval using the following formula:

[0018]

[0019] When no VR event is sensed, the QTc interval is a baseline QTc interval, wherein the baseline QTc interval is a programmable parameter.

[0020] Preferably, the ventricle sensing module senses a VR event within a VR sensing interval, when a VR event with a signal value exceeding a VR sensing threshold is sensed, the pacing control module terminates the VR sensing interval, acquires the occurrence time of the VR event from the clock / timing module, stores the VR event type and the occurrence time into the data storage module, then adjusts the sensing threshold to a VS sensing threshold, and starts another blank sensing period after the VR sensing interval.

[0021] Preferably, the ventricle sensing module senses a VR event within a VR sensing interval, when no VR event is sensed, it is determined as one T-wave undersensing, and when T-wave undersensing occurs, the sensing threshold is directly adjusted to a VS sensing threshold.

[0022] Preferably, calculating a QTc-indicated pacing interval based on the QTc interval comprises:

[0023] When the QTc interval ≤ the minimum QTc interval, the QTc-indicated pacing interval is equal to the minimum pacing interval;

[0024] When the QTc interval ≥ the baseline QTc interval, the QTc-indicated pacing interval is equal to the baseline pacing interval;

[0025] When the minimum QTc interval < the QTc interval < the baseline QTc interval, the QTc-indicated pacing interval is:

[0026]

[0027] Wherein, the baseline QTc interval, the minimum QTc interval, the baseline pacing interval and the minimum pacing interval are all programmable parameters.

[0028] Preferably, the ventricle sensing module further uses a VS sensing threshold for event sensing, and when a signal value exceeds the VS sensing threshold, it is identified as a VS event.

[0029] Preferably, after the pacing control module determines the final pacing interval, it controls the clock / timing module to time the final pacing interval, and controls the ventricle pacing module to execute a VP event within the final pacing interval.

[0030] Preferably, the clock / timing module controls the motion information processing module to update the sensor-indicated pacing interval at fixed intervals. When the motion information processing module detects user movement, it gradually shortens the sensor-indicated pacing interval to the minimum pacing interval each time it updates the sensor-indicated pacing interval. When it detects that the user is not in motion, it gradually extends the sensor-indicated pacing interval to the baseline pacing interval. The updated sensor-indicated pacing interval is stored in the data storage module, and the pacing control module can call it as needed.

[0031] Preferably, the programmable parameters are stored in a data storage module and set by the doctor according to the user's physiological state.

[0032] Compared with the prior art, the frequency adaptive pacing device based on QTc interval and acceleration sensor provided in this embodiment of the invention has at least the following beneficial effects:

[0033] This invention incorporates QTc interval measurement and calculation into frequency adaptive pacing based on accelerometer sensors. The dynamically updated frequency response pacing interval integrates the QTc-indicated pacing interval and the sensor-indicated pacing interval. This allows for the integration of changes in patient activity and metabolism, enabling adaptive adjustment of the pacing frequency to accommodate these variations. This results in accurate and timely frequency adaptive pacing. Compared to current mainstream accelerometer-based frequency adaptive pacing devices, this invention eliminates the need for additional hardware sensors, such as physiological sensors. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the frequency adaptive pacing device based on QTc interval and acceleration sensor provided in the embodiment;

[0036] Figure 2 This is a schematic diagram illustrating the adjustment of the perception blank period and perception threshold during the recognition of VS events and VR events provided in the embodiment.

[0037] Figure 3 This is a schematic diagram of VR sensing interval and sensing threshold adjustment when T wave is not detected, provided in the embodiment.

[0038] Figure 4 This is a mapping diagram between the current QTc interval and the QTc-indicating pacing interval provided in the embodiment;

[0039] Figure 5 This is a flowchart illustrating the workflow following a VR event, as provided in the embodiment.

[0040] Figure 6 This is a flowchart illustrating the workflow after the VP and VS events provided in the embodiment. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of this invention.

[0042] The technical concept of this invention is as follows: Addressing the technical problems of frequency adaptive pacing devices based on accelerometers being unable to adaptively pac according to changes in the patient's metabolic rate, frequency adaptive pacing devices based on physiological sensors requiring additional hardware costs and having complex structures, and frequency adaptive pacing devices based on QT intervals being unable to accurately and timely track changes in the patient's motion state, this invention provides a frequency adaptive pacing device based on both QTc interval and accelerometers. By combining the advantages of QTc interval calculation and accelerometers to achieve frequency adaptive pacing, it can adaptively change the pacing frequency in response to changes in the patient's exercise and metabolic rate, and at the same time, it does not require additional hardware sensors compared to mainstream cardiac pacing devices.

[0043] like Figure 1 As shown in the embodiment, a frequency adaptive pacing device 10 based on QTc interval and acceleration sensor includes a ventricular sensing module 11, a ventricular pacing module 12, a clock / timing module 13, a pacing control module 14, an acceleration sensor module 15, a motion information processing module 16, and a data storage module 17. The ventricular sensing module 11 senses spontaneous ventricular electrical signals, including spontaneous ventricular depolarization waves (QRS waves) and ventricular repolarization waves (T waves). The ventricular pacing module 12 is responsible for delivering ventricular pacing pulses. The acceleration sensor module 15 is responsible for collecting motion acceleration information from the pacemaker-implanted patient. The motion information processing module 16 is responsible for processing the motion acceleration information collected by the acceleration sensor module 15 and outputting sensor-indicated pacing intervals. The clock / timing module 13 is responsible for timing and recording various events. The pacing control module 14 is responsible for various numerical calculations and pacing control. The data storage module 17 is responsible for storing various types of data.

[0044] In this invention, the frequency adaptive pacing device defines the event of the ventricular autonomous depolarization wave detected by the ventricular sensing module 11 as a ventricular sense (VS) event, or simply a VS event, and the event of the ventricular pacing module 12 issuing a pacing pulse as a ventricular pacing (VP) event, or simply a VP event. After the VS and VP events, the pacing control module 14 initiates pacing interval timing based on the current pacing interval. If no VS event is detected by the end of the pacing interval timing, the pacing control module 14 controls the ventricular pacing module 12 to issue a pacing pulse. The pacing control module 14 obtains the occurrence time of each VP and VS event through the clock / timing module 13, and uniformly identifies the interval between two VP or VS events (i.e., VP-VP interval, VP-VS interval, VS-VS interval, and VS-VP interval) as the ventricular interval (unit: milliseconds). The ventricular interval participates in the calculation of the QTc interval and T-wave sensing timing.

[0045] In the frequency adaptive pacing device of this invention, the ventricular sensing module 12 collects the user's electrocardiogram (ECG) signals. Besides sensing and identifying the ventricular autonomous depolarization wave (QRS wave) as a VS event, it also needs to identify the ventricular repolarization wave (T wave). The event of identifying the ventricular repolarization wave is defined as a ventricular repolarization (VR) event, or simply a VR event. Specifically, after a VP or VS event, the pacing control module 14 sets a pacing interval timing via the clock / timing module 13. If a QRS wave is sensed during the pacing interval timing, i.e., ventricular autonomous depolarization, it is identified as a VS event. If no VS event is identified by the time the pacing interval timing expires, the pacing control module 14 controls the ventricular pacing module 12 to deliver pacing pulses, which is then identified as a VP event. This invention achieves frequency adaptive pacing by dynamically updating the pacing interval during operation.

[0046] In the frequency adaptive pacing device of this invention, both the ventricular depolarization wave (QRS wave) and the ventricular repolarization wave (T wave) are detected and identified by the ventricular sensing module 11. The T wave amplitude is smaller than the QRS wave and its amplitude is unstable. Therefore, different sensing thresholds are used for the QRS wave (VS event) and the T wave (VR event), i.e., both the VS sensing threshold and the VR sensing threshold are used for sensing. Figure 2 As shown, when using the VS perception threshold, if a signal exceeding the VS perception threshold is detected, it is identified as a VS event. A perception gap period is then initiated. After the perception gap period ends, the perception threshold is adjusted to the VR perception threshold, and a VR perception interval is activated. If a signal exceeding the VR perception threshold is detected during the VR perception interval, it is identified as a VR event. Another perception gap period is then initiated. After the second perception gap period ends, the perception threshold is set back to the VS perception threshold. Figure 3 As shown, if no signal exceeding the VR sensing threshold is detected during the VR sensing interval, it is determined that the T wave was not identified in that cycle, and the sensing threshold is adjusted to the VS sensing threshold. Similar to VS events, after the ventricular pacing pulse is delivered, i.e., the VP event, a sensing gap is first initiated. After the sensing gap, the sensing threshold is adjusted to the VR sensing threshold, and the VR sensing interval is activated simultaneously. During the sensing gap, no event recognition is performed; the existence of the sensing gap is to avoid continuous recognition of the same event.

[0047] Among them, the sensing gap, basic VR sensing interval, VS sensing threshold, and VR sensing threshold related to ventricular event sensing are all programmable parameters. Doctors can set these parameters according to the user's physiological condition. The set parameters are saved in the data storage module 17, and the pacing control module 14 can call them as needed. In this embodiment of the invention, the basic VR sensing interval is 450ms, the VR sensing threshold is 1mV, and the VS sensing threshold is 2.5mV.

[0048] Based on the aforementioned VS sensing threshold and VR sensing threshold settings, after VP and VS events, the pacing control module 14 controls the clock / timing module 13 to activate T-wave sensing timing after the sensing blank period, and simultaneously sets the sensing threshold to a smaller VR sensing threshold. If ventricular electrical activity exceeding the threshold is detected during the VR sensing interval, a T-wave is detected and determined as a VR event. Figure 5 As shown, upon detecting a VR event, the pacing control module 14 terminates the VR sensing interval, obtains the event occurrence time from the clock / timing module 13, stores the VR event type and occurrence time in the data storage module 17, then adjusts the sensing threshold to the VS sensing threshold, and initiates a sensing blank period. If no VR event is detected within the VR sensing interval, it is determined to be a T-wave missed sensing event. When a T-wave missed sensing event occurs, the pacing control module 14 directly adjusts the sensing threshold to the VS sensing threshold. After both the VR event and the T-wave missed sensing event occur, the sensing threshold of the ventricular sensing module 11 is set to the VS sensing threshold.

[0049] During the operation of the pacemaker, the pacing control module 14 controls the clock / timing module 13 to activate different sensing timings and sets the sensing threshold of the ventricular sensing module 11. After sensing a VS event through the ventricular sensing module or executing a VP event through the ventricular pacing module, the pacing control module 14 executes the following workflow, such as... Figure 6 As shown, it includes:

[0050] The pacing control module 14 obtains the occurrence time of the current event (VS event or VP event) from the clock / timing module 13, stores the current event type and occurrence time into the data storage module 17, and obtains the occurrence time of the previous VS event / VP event and the current VR event from the data storage module 17 to obtain the VS-VR interval and VP-VR interval. The VS-VR interval represents the interval between the spontaneous depolarization and repolarization of the ventricle recognized by the pacemaker, and the VP-VR interval represents the interval between the pacemaker delivering a pulse and recognizing ventricular repolarization. The VS-VR interval and VP-VR interval are uniformly recognized as the QT interval, and the current ventricular interval is also calculated.

[0051] Simultaneously, the VR sensing interval is calculated based on the current pacing interval and the previous ventricular interval:

[0052]

[0053] Among them, the current pacing interval is the preset pacing interval, the baseline VR sensing interval is the VR sensing interval when the heart rate is 60 bpm (i.e., the ventricular interval is 1000 ms), the standard ventricular interval corresponds to the ventricular interval value at a heart rate of 60 bpm, i.e., 1000 ms, the baseline VR sensing interval is a programmable parameter, and the units of VR sensing interval, baseline VR sensing interval, current pacing interval and previous ventricular interval are all milliseconds (ms).

[0054] The pacing control module 14 controls the ventricular sensing module 11 to adjust the pacing threshold to the VR sensing threshold, and activates the sensing blank period and the VR sensing interval after the sensing blank period. The ventricular sensing module 11 is then controlled to perform VR event sensing during the VR sensing interval. Specifically, when a VR event with a signal value exceeding the VR sensing threshold is detected, the pacing control module ends the VR sensing interval, obtains the VR event occurrence time from the clock / timing module, stores the VR event type and occurrence time in the data storage module, then adjusts the sensing threshold to the VS sensing threshold, and activates another sensing blank period after the VR sensing interval. If no VR event is detected, it is determined to be a T-wave missed sensing. When T-wave missed sensing occurs, the sensing threshold is directly adjusted to the VS sensing threshold.

[0055] In the event of a VS or VP event, the pacing control module 14 calculates the QTc interval value based on the length of the ventricular interval ending with the VS or VP event and the QT interval within the ventricular cycle. Specifically, the QTc interval is calculated based on whether the ventricular sensing module 11 senses the VR event within the VR sensing interval. Specifically, when no VR event is sensed, the QTc interval is the base QTc interval; when a VR event is sensed, the interval from the VS event to the VR event or the interval from the VP event to the VR event is taken as the QT interval, and the QTc interval is calculated based on the QT interval using the following formula:

[0056]

[0057] Wherein, the units of QTc interval, QT interval and ventricular interval are all milliseconds (ms).

[0058] After each VS or VP event, the pacing control module 14 calculates the QTc-indicated pacing interval according to the QTc interval. The QTc interval corresponds to a unique QTc-indicated pacing interval (QTc-PI). The QTc-indicated pacing interval can be calculated according to the current QTc interval (QTc), basic QTc interval (BasicQTc), minimum QTc interval (MinQTc), basic pacing interval (BasicPI), and minimum pacing interval (MinPI), which specifically includes:

[0059] When the QTc interval is ≤ the minimum QTc interval, the QTc-indicated pacing interval is equal to the minimum pacing interval;

[0060] When the QTc interval is ≥ the basic QTc interval, the QTc-indicated pacing interval is equal to the basic pacing interval;

[0061] When the minimum QTc interval < QTc interval < basic QTc interval, the QTc-indicated pacing interval is:

[0062]

[0063] Wherein, the basic QT interval, minimum QT interval, basic pacing interval and minimum pacing interval are programmable parameters, and the doctor can program and set specific values according to the user's physiological state. The parameters after setting are stored in the data storage module 17, and the pacing control module 14 calls them as needed. By setting the basic QT interval, minimum QT interval, basic pacing interval and minimum pacing interval, a unique mapping from the current QT interval to the QT-indicated pacing interval can be established, as Figure 4 shown.

[0064] The pacing control module 14 acquires the sensor-indicated pacing interval output by the motion information processing module 16, compares the QTc-indicated pacing interval with the sensor-indicated pacing interval, uses the shorter of the two as the final pacing interval, then controls the clock / timing module to time the final pacing interval, and controls the ventricular pacing module to execute the VP event within the final pacing interval, then ends the process. In an example of the present invention, the basic pacing interval is set to 1000 ms, the minimum pacing interval is set to 500 ms, the basic QTc interval is set to 400 ms, and the minimum QTc interval is set to 200 ms.

[0065] The accelerometer sensor module 15, primarily composed of an accelerometer sensor (specifically a triaxial accelerometer), continuously collects motion acceleration information during pacemaker operation. The clock / timing module 13 controls the acceleration processing module 15 to periodically process data collected over a previous period, determine the user's motion state, and update the sensor-indicated pacing interval (S-PI) value. The sensor-indicated pacing interval obtained through the accelerometer sensor can be flexibly implemented; one feasible implementation is described in patent CN112933411B.

[0066] The clock / timing module 13 controls the motion information processing module 16 to update the sensor indication pacing interval at fixed intervals. When the motion information processing module 16 detects user movement, it will gradually shorten the sensor indication pacing interval to the minimum pacing interval (500ms in this example) each time it updates the sensor indication pacing interval. When it detects that the user is not in motion, it will gradually extend the sensor indication pacing interval to the basic pacing interval (1000ms in this example). The updated sensor indication pacing interval is stored in the data storage module 17, and the pacing control module 14 can call it as needed.

[0067] In this invention, the frequency adaptive pacing device incorporates QTc interval measurement and calculation on top of frequency adaptive pacing based on an accelerometer. The dynamically updated frequency response pacing interval integrates the QTc-indicated pacing interval and the sensor-indicated pacing interval. The device adjusts the detected QT interval based on a sensing threshold and calculates the QTc interval. A mapping relationship is constructed from the QTc interval to the calculated QTc-indicated pacing interval. The minimum QTc interval, baseline QTc interval, minimum pacing interval, and baseline pacing interval used in the mapping are programmable parameters that can be flexibly set according to the specific circumstances of different patients. In summary, the QTc-indicated pacing interval and the sensor-indicated pacing interval are continuously updated during the operation of the pacing device. After VP and VS events, the pacing control module dynamically updates the pacing interval based on the shorter interval between the current QT-indicated pacing interval and the sensor-indicated pacing interval, thus achieving frequency adaptive pacing.

[0068] The specific embodiments described above illustrate the technical solution and beneficial effects of the present invention in detail. It should be understood that the above description is only the most preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, additions, and equivalent substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A frequency-adaptive pacing device based on QTc interval and acceleration sensor, characterized in that, comprising a ventricular sensing module, a ventricular pacing module, a clock / timing module, a pacing control module, an acceleration sensor module, a motion information processing module and a data storage module; the motion information processing module updates a sensor-indicated pacing interval based on motion acceleration information collected by the acceleration sensor module; after the pacing control module senses a VS event through the ventricular sensing module or executes a VP event through the ventricular pacing module, the pacing control module acquires historical event data from the data storage module to calculate a QTc interval, calculates a QTc-indicated pacing interval according to the QTc interval, and selects the smaller one of the sensor-indicated pacing interval and the QTc-indicated pacing interval as a final pacing interval, so as to realize rate-adaptive pacing; wherein acquiring the historical event data from the data storage module to calculate the QTc interval comprises: acquiring a current pacing interval and a previous ventricular interval from the historical event data, and calculating a VR sensing interval by the following formula: wherein a basic VR sensing interval is a programmable parameter; the pacing control module controls the ventricular sensing module to adjust a pacing threshold to a VR sensing threshold, starts a sensing blanking period and the VR sensing interval after the sensing blanking period, and controls the ventricular sensing module to perform VR event sensing within the VR sensing interval; the pacing control module calculating the QTc interval in different situations according to whether the ventricular sensing module senses a VR event within the VR sensing interval comprises: when a VR event is sensed, taking an interval from a VS event to the VR event or an interval from a VP event to the VR event as a QT interval, and calculating the QTc interval by the following formula according to the QT interval: when no VR event is sensed, the QTc interval is a basic QTc interval, wherein the basic QTc interval is a programmable parameter; calculating the QTc-indicated pacing interval according to the QTc interval comprises: when the QTc interval is less than or equal to a minimum QTc interval, the QTc-indicated pacing interval is equal to a minimum pacing interval; when the QTc interval is greater than or equal to a basic QTc interval, the QTc-indicated pacing interval is equal to a basic pacing interval; when the minimum QTc interval < the QTc interval < the basic QTc interval, the QTc-indicated pacing interval is: wherein the basic QTc interval, the minimum QTc interval, the basic pacing interval and the minimum pacing interval are all programmable parameters.

2. The frequency adaptive pacing device based on QTc interval and acceleration sensor according to claim 1, characterized in that, when the ventricular sensing module performs VR event sensing within the VR sensing interval and senses a VR event with a signal value exceeding the VR sensing threshold, the pacing control module ends the VR sensing interval, acquires the occurrence time of the VR event from the clock / timing module, stores the type and occurrence time of the VR event into the data storage module, then adjusts the sensing threshold to a VS sensing threshold, and starts another sensing blanking period after the VR sensing interval.

3. The frequency adaptive pacing device based on QTc interval and acceleration sensor according to claim 1, characterized in that, when the ventricular sensing module performs VR event sensing within the VR sensing interval and does not sense a VR event, it is determined as one T-wave undersensing; when T-wave undersensing occurs, the sensing threshold is directly adjusted to the VS sensing threshold.

4. The frequency adaptive pacing device based on QTc interval and acceleration sensor according to claim 1, characterized in that, the ventricular sensing module also uses the VS sensing threshold for event sensing, and a signal exceeding the VS sensing threshold is identified as a VS event.

5. The frequency adaptive pacing device based on QTc interval and acceleration sensor according to claim 1, characterized in that, The pacing control module determines the final pacing interval, then controls the clock / timing module to time the final pacing interval, and controls the ventricular pacing module to execute the VP event within the final pacing interval.

6. The frequency adaptive pacing device based on QTc interval and acceleration sensor according to claim 1, characterized in that, The clock / timing module controls the motion information processing module to update the sensor-indicated pacing interval once at a fixed interval. When the motion information processing module detects the user's movement, it will gradually shorten the sensor-indicated pacing interval to the minimum pacing interval each time it updates the sensor-indicated pacing interval. When the system detects that the user is not in motion, the sensor-indicated pacing interval is gradually extended to the baseline pacing interval. The updated sensor-indicated pacing interval is stored in the data storage module, and the pacing control module can call it as needed.

7. The frequency adaptive pacing device based on QTc interval and acceleration sensor according to claim 1, characterized in that, The programmable parameters are stored in the data storage module and are set by the doctor according to the user's physiological state.

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