A pacemaker with delayed response function and a cardiac pacing device

Abstract

This invention discloses a pacing frequency adaptive adjustment device with a delayed response function. By adding a delayed response setting module, the pacing frequency decreases with a delay after high-intensity exercise, meeting the patient's high metabolic needs. By using the patient's target heart rate and current actual heart rate to jointly determine the patient's exercise status, it can track changes in pacing frequency in a timely and accurate manner, effectively improving the patient's quality of life. The target heart rate threshold, maximum delayed response time, and curve type in the target heart rate-delay response curve can be programmed to different parameters according to the patient's actual situation, meeting the personalized needs of different patients. A cardiac pacing device is also disclosed, employing a pacing frequency adaptive adjustment device that can delay the decrease in cardiac pacing frequency after exercise. Based on this cardiac pacing frequency, cardiac pacing pulse signals are sent, which can improve pacing effectiveness and ensure life safety.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, specifically relating to a pacing frequency adaptive adjustment device and a cardiac pacing device with a delayed response function. Background Technology

[0002] Rate adaptive pacing is an important function designed to meet the varying metabolic demands of pacemaker patients by providing sufficient cardiac output. The pacemaker can adjust the pacing rate in real time using sensed physiological and non-physiological parameters. Currently, clinically applied rate adaptive pacing solutions primarily rely on minute ventilation (MV), closed-loop stimulation, and accelerometers. MV, the product of ventilation rate and tidal volume, is linearly related to aerobic oxygen consumption during exercise and is the physiological variable that best reflects metabolic demands during exercise. However, it also has significant drawbacks: it cannot function properly in complex electromagnetic interference environments; hyperventilation increases pacing rate; breath-holding decreases pacing rate; it has poor sensitivity and slow response speed. Closed-loop stimulation (CLS) is obtained by measuring intracardiac impedance throughout ventricular systole. Its theoretical basis is the closed-loop regulation mechanism of cardiac output by the autonomic nervous system. It can adaptively pace under conditions of exercise, mental activity, and hemodynamic changes. However, its disadvantages include: overly sensitive adjustment leading to inappropriate increases in heart rate, and inability to function normally during mode transitions. Accelerometers adjust the pacing frequency based on the acceleration signal of human motion and are currently the most widely used sensors in pacemakers. Their advantages include good long-term stability and high sensitivity; their disadvantages include poor specificity and inability to directly sense changes in physiological state.

[0003] Adaptive pacing frequency adjustment using an accelerometer involves the following steps: assessing exercise intensity based on the acceleration signal, calculating the target heart rate based on the exercise intensity, and gradually transitioning from the current pacing frequency to the target heart rate. To meet the personalized needs of different patients, the programming parameters related to adaptive pacing typically include: exercise intensity assessment threshold, slope of the target heart rate calculation curve, and positive / negative time constants of the pacing frequency transition curve. However, because the accelerometer only uses the patient's body motion signal as input, the heart rate will rise rapidly when the patient begins to exercise, but will immediately begin to decline when the patient finishes exercising.

[0004] In healthy individuals, the heart is innervated by the cardiac sympathetic nervous system and the parasympathetic-vagus nerve. During exercise, the postganglionic neurons of the cardiac sympathetic nervous system release norepinephrine, which binds to β-adrenergic receptors on the myocardial cell membrane, leading to an increased heart rate, accelerated atrioventricular junctional conduction, and increased myocardial contractility. After exercise, the neurotransmitter acetylcholine released from the postganglionic fibers of the cardiac vagus nerve acts on M-type cholinergic receptors in myocardial cells, resulting in a decreased heart rate, weakened atrial myocardial contractility, and a shortened atrial myocardial refractory period. In reality, the body's metabolic demands are still high immediately after strenuous exercise. Due to the antagonistic effect of the cardiac sympathetic and vagus nerves, the heart rate does not immediately begin to decrease but remains at a relatively high level for a period before starting to decline.

[0005] For pacemaker patients whose heart rate is adaptively adjusted by the accelerometer, if the heart rate drops rapidly immediately after exercise, it cannot meet the metabolic needs of the pacemaker patient. In severe cases, it can cause discomfort symptoms such as dizziness and nausea, or even fainting, which seriously affects the patient's quality of life. Summary of the Invention

[0006] To address the problem that the pacing frequency of a frequency adaptive pacemaker using an accelerometer drops immediately after the patient finishes exercising, this invention provides a pacing frequency adaptive adjustment device and a cardiac pacing device with a delay response function.

[0007] In a first aspect, the embodiment provides a pacing frequency adaptive adjustment device with a delay response function, including a data acquisition module, an exercise volume assessment module, a target heart rate calculation module, a delay response setting module, and a pacing frequency adjustment module;

[0008] The data acquisition module is used to convert the patient's physical activity signals acquired by the accelerometer into acceleration signals;

[0009] The exercise volume assessment module is used to assess the current exercise volume based on the acceleration signal;

[0010] The target heart rate calculation module is used to determine the target heart rate that should be achieved in the current exercise state based on the amount of exercise.

[0011] The delay response setting module is used to determine the delay response status and set the delay duration based on the relative relationship between the current heart rate and the target heart rate, so that the pacing frequency remains for a period of time after the end of exercise before it begins to decrease.

[0012] The pacing frequency adjustment module is used to determine and output the cardiac pacing frequency at the next moment based on the delay response state, thereby realizing adaptive adjustment of the cardiac pacing frequency.

[0013] Secondly, an embodiment provides a cardiac pacing device, characterized in that it includes:

[0014] The cardiac pacing frequency adaptive adjustment device with delay response function as described in the first aspect;

[0015] The pacing control unit is communicatively connected to the adaptive adjustment device and is used to send cardiac pacing events, i.e. cardiac pacing pulse signals, according to the cardiac pacing frequency output by the adaptive adjustment device.

[0016] The technical solutions provided in the above embodiments have at least the following beneficial effects:

[0017] The adaptive pacing frequency adjustment device provided in this embodiment, by adding a delay response setting module, allows the pacing frequency to decrease after the patient finishes high-intensity exercise, thus meeting the patient's high metabolic needs. By using the patient's target heart rate and current actual heart rate together to determine the patient's exercise status, it can track changes in pacing frequency in a timely and accurate manner, effectively improving the patient's quality of life. The target heart rate threshold, maximum delay response time, and curve type in the target heart rate-delay response curve can be programmed to different parameters according to the patient's actual situation, which can meet the personalized needs of different patients.

[0018] The cardiac pacing device provided in this embodiment employs a pacing frequency adaptive adjustment device that can delay the decrease of cardiac pacing frequency after exercise and send cardiac pacing pulse signals according to the cardiac pacing frequency, thereby improving pacing effect and ensuring life safety. Attached Figure Description

[0019] 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.

[0020] Figure 1 This is a schematic diagram of the structure of a pacing frequency adaptive adjustment device with delay response function provided in one embodiment;

[0021] Figure 2 This is a flowchart of an embodiment of an exercise volume assessment using a three-threshold comparison method;

[0022] Figure 3 This is an embodiment of the exercise-target heart rate curve, wherein (a) and (b) are exercise-target heart rate curves at different exercise thresholds Tm and different slopes, respectively;

[0023] Figure 4Here is a target heart rate-delay response curve provided in one embodiment, wherein (a), (b), and (c) are target heart rate-delay response curves of step function type, linear function type, and sigmoid function type, respectively;

[0024] Figure 5 This is an embodiment of time-pacing frequency rise curves for different rise times, wherein (a) and (b) are linear and exponential time-pacing frequency rise curves for different rise times, respectively.

[0025] Figure 6 This is an embodiment of time-pacing rate decrease curves for different fall times, wherein (a) and (b) are linear and exponential time-pacing rate decrease curves for different fall times, respectively;

[0026] Figure 7 This is a flowchart of a pacing frequency adjustment method that incorporates a delay response function, provided in one embodiment.

[0027] Figure 8 This is a schematic diagram of the structure of an adaptive adjustment device for pacing frequency with delay response function provided in another embodiment;

[0028] Figure 9 This is a schematic diagram of the structure of a cardiac pacing device provided in one embodiment. Detailed Implementation

[0029] 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.

[0030] To address the issue that the pacing rate of a frequency-adaptive pacemaker using an accelerometer drops immediately after the patient's exercise, this invention provides a pacing rate adaptive adjustment device and a cardiac pacing device with a delay response function, belonging to the category of implantable medical devices in the field of medical devices.

[0031] Figure 1 This is a schematic diagram of a pacing frequency adaptive adjustment device with delay response function provided in one embodiment. Figure 1As shown, the pacing frequency adaptive adjustment device 100 with delay response function provided in the embodiment includes a data acquisition module 101, an exercise volume assessment module 102, a target heart rate calculation module 103, a delay response setting module 104, and a pacing frequency adjustment module 105. The data acquisition module 101 is communicatively connected to the exercise volume assessment module 102, the exercise volume assessment module 102 is communicatively connected to the target heart rate calculation module 103, the target heart rate calculation module 103 is communicatively connected to the delay response setting module 104, and the delay response setting module 104 is communicatively connected to the pacing frequency adjustment module 105. The data acquisition module 101 converts the patient's physical activity signals acquired by the accelerometer into acceleration signals; the exercise volume assessment module 102 assesses the current exercise volume based on the acquired acceleration signals using a threshold comparison method; the target heart rate calculation module 103 determines the target heart rate that should be achieved at the current moment based on the exercise volume; the delay response setting module 104 determines the delay response status and sets the delay duration based on the relative relationship between the current heart rate and the target heart rate, so that the pacing frequency remains for a period of time after the exercise ends before starting to decrease; and the pacing frequency adjustment module 105 determines and outputs the cardiac pacing frequency at the next moment based on the delay response status.

[0032] In its specific implementation, the data acquisition module 101 uses an accelerometer to collect body activity signals and converts them into analog acceleration signals. These analog acceleration signals undergo preprocessing such as modulation, amplification, phase-sensitive demodulation, anti-aliasing filtering, and analog-to-digital conversion before being converted into digital acceleration signals, simply referred to as acceleration signals. In this embodiment, the accelerometer can be a 3-axis capacitive MEMS accelerometer. Considering the characteristics of human motion acceleration, the amplitude detection range is set to ±2g. The analog-to-digital converter uses a 10-bit resolution. Considering that the main frequency of acceleration during daily human activities is usually below 4Hz, the accelerometer sampling rate is fixed at 10Hz, i.e., the sampling interval Δn is 100ms. The parameters involved in the above acceleration signal acquisition process are illustrative examples and can be set independently in actual applications.

[0033] In its specific implementation, the exercise volume assessment module 102 calculates the relative acceleration value of the main axis based on the acceleration signal at each sampling moment, and compares it with the set single or multiple relative acceleration thresholds. The relative acceleration value of the main axis falls within different relative acceleration threshold ranges, corresponding to different weights of exercise volume scores. The sum of the exercise volume scores of all sampling moments within a certain period of time is taken as the exercise volume at the current moment.

[0034] Figure 2 This is a flowchart illustrating an embodiment of an exercise volume assessment using a three-threshold comparison method. Figure 2As shown in the figure, this embodiment uses a three-axis acceleration sensor to obtain the acceleration sampling value Ai(n) of each axis at time n, where i = x, y, z, respectively representing the three single axes of x, y, and z. The absolute value of the difference between the acceleration sampling values of each axis at two adjacent sampling times is used as the relative acceleration of each axis, and the axis with the largest relative acceleration is taken as the main axis. That is, the relative acceleration of the main axis at the current time n is J(n)=max(|Ai(n)-Ai(n - 1)|). When evaluating the amount of exercise at the current time, multiple gears of relative acceleration thresholds are preset. In this embodiment, three gears of relative acceleration thresholds Tj1, Tj2, and Tj3 are preset, and Tj1 < Tj2 < Tj3. When the relative acceleration J(n) of the main axis belongs to the interval [0, Tj1), the corresponding exercise score value S(n)=s1. When J(n) belongs to the interval [Tj1, Tj2), the corresponding exercise score value S(n)=s2. When J(n) belongs to the interval [Tj2, Tj3), the corresponding exercise score value S(n)=s3. When J(n) belongs to the interval [Tj3, +∞), the corresponding exercise score value S(n)=s4. If the current is the exercise amount evaluation time N, then the sum of the exercise score values S(k) of all sampling times within the previous t1 time range with the current time as the end point is used as the exercise amount M(N) at the current time, that is So far, a process of evaluating the amount of exercise is completed, and it waits for the arrival of the next sampling time n+Δn. In this embodiment, the preset multi-gear relative acceleration thresholds are in a multiple relationship. Take Tj1 = 150mg, Tj2 = 300mg, and Tj3 = 600mg as the relative acceleration thresholds; take s1 = 0, s2 = 1, s3 = 2, and s4 = 4 as the exercise score values; the exercise amount evaluation duration t1 is 6 seconds. Since the sampling rate is 10Hz, M(N) is the sum of the exercise score values of the 60 sampling times before the current exercise amount evaluation time. In this process, the above preset parameter values are only for illustrative purposes and can be set according to requirements in actual applications.

[0035] When the target heart rate calculation module 103 is specifically implemented, a preset exercise amount threshold Tm is set. When the exercise amount evaluation value at the current moment is less than the exercise amount threshold, that is, M(N) < Tm, it is determined that the current moment is in a stationary state, and the target heart rate corresponding to the stationary state is the reference heart rate in the quiet state; when the exercise amount at the current moment is not less than the exercise amount threshold, that is, M(N) ≥ Tm, it is determined that the current moment is in a motion state, and the target heart rate corresponding to the motion state is calculated based on the exercise amount, the exercise amount threshold, and the slope slope of the exercise amount - target heart rate curve, that is, the target heart rate TR(N) = slope × (M(N) - Tm), where the exercise amount - target heart rate curve indicates the corresponding relationship between the exercise amount M(N) and the target heart rate TR(N) at the current moment, and the target heart rate TR(N) is between the reference heart rate HRbase and the maximum heart rate HRmax, that is, the value range of TR(N) is [HRbase, HRmax].

[0036] In the embodiment, Tm, slope, HRmax, and HRbase are all programmable parameters. Tm can be set to at least three gears: low (Tm1), medium (Tm2), and high (Tm3) according to the value. For example Figure 3 as shown in (a) below, different values of Tm will cause the exercise amount - target heart rate curve to shift left and right; slope can be set to at least three gears: fast (slope1), medium (slope2), and slow (slope3) according to different values. For example Figure 3 as shown in (b) below, different values of slope will cause the slope of the exercise amount - target heart rate curve to change. The relationship between HRmax and HRbase is HRbase < HRmax. In this embodiment, HRmax is taken as 120 bpm and HRbase is taken as 60 bpm.

[0037] When the delay response setting module 104 is specifically implemented, the delay response setting process includes:

[0038] The first step is to determine whether the current actual heart rate is less than or equal to the target heart rate. If so, the delay response function is enabled and directly enter the pacing frequency adjustment module; if not, enter the second step;

[0039] The second step is to determine whether the delay response is enabled. If so, the delay response function is disabled, and the total duration of the delay response is determined according to the target heart rate - delay response curve, and enter the pacing frequency adjustment module; if not, enter the third step;<000011​​​​The fourth step is to enter the pacing rate adjustment module if none of the above conditions are met.

[0042] In this embodiment, the target heart rate-delay response curve determines the delay response duration corresponding to different target heart rates TR(N). The total delay response duration is determined based on the target heart rate-delay response curve, including:

[0043] Preset target heart rate threshold T TR If the current target heart rate is less than the target heart rate threshold, i.e., TR(N) <T TR If the patient's current activity level is low, no delay is required, and the delay time is set to zero; if the current target heart rate is not less than the target heart rate threshold, i.e., TR(N) ≥ T TR Then the delayed response time t d Let TR(N) be the delay response time corresponding to the current target heart rate in the target heart rate-delay response curve. The target heart rate-delay response curve can be a step function, a linear function, or a sigmoid function, as shown below. Figure 4 As shown in (a), (b), and (c), the delay response time is between zero and the maximum delay response time t. dmax Between. In the example, the target heart rate threshold T TR Maximum delay response time t dmax Both the target heart rate-delay response curve type and the T value are programmable parameters. TR 90 bpm is preferred. dmax 60 seconds is a preferred setting.

[0044] In its specific implementation, the pacing rate adjustment module 105 employs different pacing rate adjustment processes depending on the different steps from entering the pacing rate adjustment module from the delay response setting module, including:

[0045] When entering the pacing rate adjustment module from the first step, the pacing rate is determined according to the time-pacing rate rise curve.

[0046] When entering the pacing rate adjustment module from the second and third steps, the pacing rate remains unchanged;

[0047] When entering the pacing rate adjustment module from the fourth step, the pacing rate is determined based on the time-pacing rate decrease curve.

[0048] In this embodiment, the time-pacing rate rise curve indicates the process of heart rate rising from HRbase to HRmax, and the pacing rate can be adjusted over time as follows: Figure 5 The linear function shown in (a) or as shown in the figure Figure 5(b) shows exponential growth, where the exponential function is more physiological. The total time required to rise from HRbase to HRmax is a programmable parameter, and in this embodiment, it is set to three levels: 15s, 30s, and 60s.

[0049] In this embodiment, the time-pacing rate decrease curve indicates the process of heart rate decreasing from HRmax to HRbase, and the pacing rate can be adjusted over time as follows: Figure 6 The linear function shown in (a) or as shown in the figure Figure 6 The exponential function shown in (b) decreases, and the exponential function is more physiological. The total time required for HRmax to decrease to HRbase is a programmable parameter, and in this embodiment, three levels are selected: 2.5 min, 5 min, and 10 min.

[0050] Figure 7 This is a flowchart illustrating the pacing frequency adjustment process incorporating a delay response function, as provided in one embodiment. Figure 7 As shown, at time N after a fixed time interval ΔN, the patient's current exercise volume M(N) is obtained, and the target heart rate TR(N) is calculated using the exercise volume-target heart rate curve. Then, different steps are performed according to different discrimination conditions to update the pacing frequency PR(N). The specific implementation process can be divided into the following steps: (1) First step: determine whether the patient's current actual heart rate HR(N) is less than or equal to TR(N). If so, the delay response function is enabled and PR(N) is determined according to the time-pacing frequency rise curve. Otherwise, proceed to the second step; (2) Second step: determine whether the delay response function is enabled. If so, the delay response function is disabled, and the total duration t of the delay response is determined according to the target heart rate-delay response curve. d (N), and let PR(N) remain unchanged, that is, PR(N) = PR(N-ΔN), otherwise proceed to the third step; (3) Third step, determine the current time t d Is (N) greater than zero? If so, update t. d (N)=t d (N-ΔN)-ΔN, and keep PR(N) unchanged, i.e. PR(N)=PR(N-ΔN), otherwise proceed to the fourth step; (4) Fourth step, when none of the above conditions are met, determine PR(N) according to the time-pacing frequency decrease curve, and then wait for the next pacing frequency update time N+ΔN. In this embodiment, the pacing frequency update time interval ΔN is taken as 2 seconds, i.e., the pacing pulse frequency is updated once every 2 seconds.

[0051] Figure 8 This is a schematic diagram of the structure of an adaptive pacing frequency adjustment device with a delay response function provided in another embodiment. (See diagram below.) Figure 8As shown, the pacing rate adaptive adjustment device 100 with delayed response function provided in the embodiment also includes a parameter setting module 801. This parameter setting module can be a programmer, which sets or adjusts programmable parameters during implantation or follow-up. The programmable parameters are all adjustable parameters in the automatic adjustment device, including the exercise threshold Tm, the baseline heart rate HRbase, the maximum heart rate HRmax, the slope of the exercise-target heart rate curve, and the target heart rate threshold Tm. TR Maximum delay response time t dmax The system includes the target heart rate-delay response curve type, and the rise and fall times of the time-pacing rate curve. Specifically, different baseline heart rate (HRbase) and maximum heart rate (HRmax) can be set based on the patient's physiological state. Different levels of exercise intensity thresholds (Tm) and slopes of the exercise intensity-target heart rate curve can be set based on the patient's daily activity heart rate response to exercise. Different target heart rate thresholds (T) can be set based on the patient's actual metabolic needs after exercise. TR Different maximum delay response times t dmax Different types of target heart rate-delay response curves can be set with different rise and fall times according to the rate of heart rate change during the patient's daily activities, so as to adapt to different patients and enable patients to obtain sufficient cardiac output under different physiological conditions and metabolic needs.

[0052] The adaptive pacing frequency adjustment device with delay response function provided in this embodiment illustrates the adaptive adjustment process of the cardiac pacing frequency using the aforementioned functional modules. These functions can be assigned to different functional modules as needed; that is, the computer program stored in the storage medium can be divided into different functional modules to complete all or part of the functions described above. In this embodiment, the adaptive adjustment device with delay response function can be implemented in an application-specific integrated circuit (ASIC), a digital signal processing (DSP), or a microcontroller (MCU).

[0053] The pacing frequency adaptive adjustment device 100 provided in this embodiment, by adding a delay response setting module 105, allows the pacing frequency to decrease after the patient finishes high-intensity exercise, thus meeting the patient's high metabolic needs. By using the patient's target heart rate and current actual heart rate together to determine the patient's exercise status, it can track changes in pacing frequency in a timely and accurate manner, effectively improving the patient's quality of life. The target heart rate threshold, maximum delay response time, and curve type in the target heart rate-delay response curve can be programmed to different parameters according to the patient's actual situation, which can meet the personalized needs of different patients.

[0054] Figure 9 This is a schematic diagram of the structure of a cardiac pacing device provided in one embodiment. Figure 9 As shown, the cardiac pacing device 900 provided in this embodiment includes: a pacing frequency adaptive adjustment device 901 with a delay response function and a pacing control unit 902. The pacing frequency adaptive adjustment device 901 with the delay response function is the aforementioned pacing frequency adaptive adjustment device 100. This adaptive adjustment device 901 is communicatively connected to the pacing control unit 902. The adaptive adjustment device 901 outputs a cardiac pacing frequency, and the pacing control unit 902 sends cardiac pacing events, i.e., cardiac pacing pulse signals, based on the cardiac pacing frequency output by the automatic adjustment device 901.

[0055] The cardiac pacing device 900 provided in the embodiment employs a pacing frequency adaptive adjustment device 100 that can delay the decrease of cardiac pacing frequency after exercise and send cardiac pacing pulse signals according to the cardiac pacing frequency, thereby improving pacing effect and ensuring life safety.

[0056] 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 pacemaker frequency adaptive adjustment device with delay response function, characterized in that, It includes a data acquisition module, an exercise volume assessment module, a target heart rate calculation module, a delay response setting module, and a pacing frequency adjustment module; The data acquisition module is used to convert the patient's physical activity signals acquired by the accelerometer into acceleration signals; The exercise volume assessment module is used to assess the current exercise volume based on the acceleration signal; The target heart rate calculation module is used to determine the target heart rate that should be achieved in the current exercise state based on the amount of exercise. The delay response setting module is used to determine the delay response status and set the delay duration based on the relative relationship between the current heart rate and the target heart rate, so that the pacing frequency remains for a period of time after exercise before starting to decrease. The delay response setting process includes: First step, determining whether the current actual heart rate is less than or equal to the target heart rate; if so, enabling the delay response function and directly entering the pacing frequency adjustment module; otherwise, proceeding to the second step; Second step, determining whether the delay response is enabled; if so, disabling the delay response function, determining the total delay response duration based on the target heart rate-delay response curve, and entering the pacing frequency adjustment module; otherwise, proceeding to the third step; Third step, determining whether the delay response duration is greater than zero; if so, subtracting the time interval between the current moment and the last pacing frequency update moment from the delay response duration, and entering the pacing frequency adjustment module; otherwise, proceeding to the fourth step; Fourth step, entering the pacing frequency adjustment module if none of the above conditions are met. The pacing frequency adjustment module is used to determine and output the cardiac pacing frequency at the next moment based on the delay response state, thereby realizing adaptive adjustment of the cardiac pacing frequency. Specifically, different pacing frequency adjustment processes are adopted according to the different steps of the delay response module when entering the pacing frequency adjustment module, including: when entering the pacing frequency adjustment module from the first step, the pacing frequency is determined according to the time-pacing frequency rising curve; when entering the pacing frequency adjustment module from the second and third steps, the pacing frequency remains unchanged; when entering the pacing frequency adjustment module from the fourth step, the pacing frequency is determined according to the time-pacing frequency falling curve.

2. The pacing frequency adaptive adjustment device with delay response function according to claim 1, characterized in that, In the exercise volume assessment module, the relative acceleration value of the main shaft is calculated based on the acceleration signal at each sampling moment, and compared with the set single or multiple relative acceleration thresholds. The relative acceleration value of the main shaft is located in different relative acceleration threshold ranges, corresponding to different weights of exercise volume scores. The sum of the exercise volume scores of all sampling moments within a period of time is taken as the exercise volume at the current moment.

3. The pacing frequency adaptive adjustment device with delay response function according to claim 1, characterized in that, In the target heart rate calculation module, a preset exercise volume threshold is set. When the exercise volume assessment value at the current moment is less than the exercise volume threshold, it is determined that the current moment is in a static state. The target heart rate corresponding to the static state is the baseline heart rate. If the amount of exercise at the current moment is not less than the exercise threshold, it is determined that the current moment is in an exercise state. The target heart rate corresponding to the exercise state is calculated based on the amount of exercise, the exercise threshold, and the slope of the exercise-target heart rate curve. The target heart rate is between the baseline heart rate and the maximum heart rate.

4. The pacing frequency adaptive adjustment device with delay response function according to claim 1, characterized in that, The determination of the total duration of the delay response based on the target heart rate-delay response curve includes: A preset target heart rate threshold is set. If the current target heart rate is less than the target heart rate threshold, the delay response time is set to zero. If the current target heart rate is not less than the target heart rate threshold, the delay response time is the delay response time corresponding to the current target heart rate in the target heart rate-delay response curve. The delay response time is between zero and the maximum delay response time.

5. The pacing frequency adaptive adjustment device with delay response function according to claim 4, characterized in that, The target heart rate-delay response curve function is a step function, a linear function, or a sigmoid function.

6. The pacing frequency adaptive adjustment device with delay response function according to claim 5, characterized in that, The time-pacing rate rise curve is a linear function or an exponential function; The time-pacing rate decrease curve is a linear function or an exponential function.

7. The pacing frequency adaptive adjustment device with delay response function according to any one of claims 1-6, characterized in that, It also includes a parameter setting module for setting acceleration threshold, exercise volume threshold, baseline heart rate, maximum heart rate, slope of the exercise volume-target heart rate curve, target heart rate threshold, maximum delay response time, target heart rate-delay response curve type, time-pacing frequency rise curve time constant, and time-pacing frequency fall curve time constant.

8. A cardiac pacing device, characterized in that, include: The cardiac pacing rate adaptive adjustment device with delay response function according to any one of claims 1-7; The pacing control unit is communicatively connected to the adaptive adjustment device and is used to send cardiac pacing events, i.e. cardiac pacing pulse signals, according to the cardiac pacing frequency output by the adaptive adjustment device.

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