An automatic atrial pacing threshold test optimization method and test optimization circuit

Abstract

The application provides an automatic atrial pacing threshold test optimization method and test optimization circuit. The test method comprises starting the test optimization circuit, completing the initialization of PVAB in the first register and PVARP in the second register, and starting the automatic atrial pacing threshold test. During the test process: when PVAB is too small and no captured atrial pacing pulse Ap is detected during the test process, the test optimization circuit is started to update the first register after optimizing PVAB; when PVARP is too large and no captured atrial pacing pulse Ap is detected during the test process, or PVARP is too small, the test optimization circuit is started to update the second register after optimizing PVARP; and if PVAB and PVARP are both in the standard range, the automatic atrial pacing threshold test is completed. The application can effectively improve the success rate and reliability of AAT test, and provides a strong guarantee for 1:1 atrioventricular synchronous contraction.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, and more specifically, this invention relates to an automatic atrial pacing threshold testing optimization method and testing optimization circuit. Background Technology

[0002] Automated atrial pacing threshold testing (AAT) is a common feature of implantable pulse generators (IPGs), including implantable pacemakers, implantable cardiac resynchronization therapy (CRT) pacemakers, and implantable cardioverter defibrillators (ICDs). When the atrial pacing threshold changes, this function optimizes the atrial pacing output energy (including pulse amplitude and pulse width) based on these changes, ensuring the atrial pacing pulse captures the myocardium to maintain 1:1 atrioventricular synchrony. Taking implantable CRT pacemakers as an example, good atrioventricular synchrony ensures the heart pumps blood effectively, maintaining good hemodynamics. If the implantable pulse generator IPG fails to optimize the atrial pacing output energy in a timely manner, resulting in a loss of atrioventricular synchrony, it will significantly limit the therapeutic effect of implantable CRT pacemakers and may even trigger a series of adverse reactions. Therefore, automated atrial pacing threshold testing (AAT) plays a crucial role in the effective operation of implantable pulse generator IPGs.

[0003] In existing technologies, the core idea of ​​the Automated Atrial Pacing Threshold (AAT) method is to increase the frequency of the atrial pacing pulse (Ap) and gradually decrease the amplitude of the pacing pulse until the atrial pacing pulse can no longer capture the myocardium. At this point, the atrial channel of the implantable pulse generator (IPG) will sense the P wave generated by its own atrial contraction. Based on this principle, the implantable pulse generator (IPG) can measure the atrial pacing threshold. Figure 11 As shown, when the energy of Ap is sufficiently high, Ap can capture the myocardium; as Figure 12 As shown, as the energy of Ap decreases, when its energy value falls below the atrial pacing threshold, Ap cannot capture the myocardium. The IPG will then sense the P wave generated by its own atrial contraction and mark it as Ars, thus determining the atrial pacing threshold. To maintain a 1:1 atrioventricular synchronization, the IPG sets a series of complex timing periods. For the atrial pathway, the two most critical timing periods are PVAB and PVARP. PVAB is the blank period for atrial sensing after a ventricular event (including ventricular sensing Vs and ventricular pacing pulse Vp). During this timing period, atrial sensing is closed, thus preventing far-field signals generated by ventricular events in the atrial pathway from affecting atrial sensing. PVARP is the refractory period for atrial sensing after a ventricular event (including Vs and Vp). Atrial events sensed during this timing period are marked as Ars and do not affect the basic timing of the IPG, preventing PMT phenomena caused by atrioventricular retrograde conduction.

[0004] For a consistent user, the interference window time of the far-field signal generated by the ventricular pathway on the atrial pathway is relatively stable, as is the conduction time of atrioventricular retrograde conduction. Therefore, setting a fixed set of PVAB and PVARP parameters is appropriate when the IPG is operating in normal mode. However, during the Automatic Atrial Pacing Threshold Test (AAT), to accurately determine the atrial pacing threshold, when the atrial test pulse is below the threshold and cannot capture the myocardium, a sufficient time window should be reserved to allow the atrial event to fall within the PVARP timing period. This requires that PVAB be shortened as much as possible, while PVARP should be appropriately extended. In particular, over time, the PVAB and PVARP settings may need to be optimized, and there will be significant differences in the PVAB and PVARP settings for different users. In other words, the PVAB and PVARP settings require different values ​​when the IPG is operating normally or during automatic atrial pacing threshold testing, and this drawback can affect the success rate of automatic atrial pacing threshold testing. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and to propose an optimized method and circuit for automatic atrial pacing threshold testing.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, this application provides an optimized method for automatic atrial pacing threshold testing, comprising the following steps:

[0008] The automatic atrial pacing threshold test optimization circuit is activated, the PVAB in the first register and the PVARP in the second register are initialized, and the automatic atrial pacing threshold test begins. During the test:

[0009] If PVAB is less than the set value x1, and no captured atrial pacing pulse Ap is detected during the automatic atrial pacing threshold test, the automatic atrial pacing threshold test optimization circuit should be activated, and the first register should be updated after optimizing PVAB.

[0010] If PVARP is too high and no captured atrial pacing pulse Ap is detected during the automatic atrial pacing threshold test, or if PVARP is too low, the automatic atrial pacing threshold test optimization circuit is activated, and the second register is updated after optimizing PVARP. Here, "too high" means PVARP is greater than a set value x2. The method for determining "too low" is as follows: when the VA event sequence type is Vp-Ars, and 3 out of 5 VA intervals satisfy: Vp-Ars interval + 10ms > PVARP, or when 3 consecutive Vp-As intervals are detected, PVARP is determined to be too low.

[0011] If PVAB is greater than or equal to the set value x1, and PVARP is neither too large nor too small, the automatic atrial pacing threshold test is completed.

[0012] Further, said optimizing PVAB comprises the following steps:

[0013] The IPG circuit module detects the current cardiac rhythm, reads the data in the first register, assigns a value to PVAB, sets an initial value of PVAB, writes the VA interval event sequence type into the third register according to the atrial sensing event type identified by the pulse generator, and writes the VA interval value recorded by the timer into the fourth register;

[0014] The comparator compares PVAB in the first register with the VA interval in the fourth register, and the counter accumulates the number of comparisons stored in the comparator. If the probability of 3 / 5 in VA intervals satisfies: VA interval < PVAB + b1, it is determined that the current PVAB is increased by a1, and optimization of PVAB is continued; otherwise, PVAB is increased by b1, the first register is updated, and optimization of PVAB is completed, wherein a1 is a first step size and b1 is a first safety margin.

[0015] Further, said optimizing PVARP comprises the following steps:

[0016] The IPG circuit module detects the current cardiac rhythm, reads the data in the second register, assigns a value to PVARP, sets an initial value of PVARP, writes the VA interval event sequence type into the third register according to the atrial sensing event type identified by the pulse generator, and writes the VA interval value recorded by the timer into the fourth register;

[0017] The comparator compares PVARP in the second register with the VA interval in the fourth register. If the probability of 3 / 5 in VA intervals satisfies: VA interval + b2 < PVARP, it is determined that the current PVARP is increased by a2, and optimization of PVARP is continued; otherwise, PVARP is increased by b2, the second register is updated, and optimization of PVARP is completed, wherein a2 is a second step size and b2 is a second safety margin.

[0018] Further, a protection mechanism is provided for the step of optimizing PVARP, and the optimized PVARP in the protection mechanism satisfies:

[0019] optimized PVARP < basic cycle length - AV interval - a3,

[0020] wherein both the basic cycle length and the AV interval are obtained by the IPG, and a3 is a third safety margin.

[0021] Furthermore, the initial value of the first step length a1 is 50ms, and the first step length a1 is gradually increased in 5ms increments to perform PVAB optimization.

[0022] Furthermore, the first safety margin b1 is set to 10ms.

[0023] Furthermore, the initial value of the second step size a2 is the PVARP setting value under normal working mode, and PVARP optimization is performed. The second safety margin b2 is set to 10ms.

[0024] Furthermore, the third safety margin a3 is set to 300ms.

[0025] Secondly, this application provides an automatic atrial pacing threshold testing optimization circuit, which includes an IPG circuit module, a timer, a register, a comparator, and a counter.

[0026] The registers include a first register, a second register, a third register, and a fourth register; the IPG circuit module includes a pacing circuit unit and a sensing circuit unit.

[0027] The pacing circuit unit is electrically connected to the timer and is used to start the timer when Vp is delivered;

[0028] The sensing circuit unit is electrically connected to the timer and is used to send signals to the timer after sensing As and Ars, so that the timer completes one timing cycle.

[0029] The first register is electrically connected to the IPG circuit module and the comparator respectively, and is used to record the optimized PVAB value;

[0030] The second register is electrically connected to the IPG circuit module and the comparator respectively, and is used to record the optimized PVARP value;

[0031] The third register is electrically connected to the timer and comparator respectively, and is used to record the VA interval event sequence type;

[0032] The fourth register is electrically connected to the timer and the comparator respectively, and is used to record the VA interval value;

[0033] The comparator is electrically connected to the counter and is used to compare the VA interval value recorded in the fourth register with the optimized PVAB value recorded in the first register and the PVARP value recorded in the second register.

[0034] The counter is electrically connected to the first register and is used to accumulate the number of comparisons of the comparator. After the number of comparisons reaches a preset target, the first register or the second register is updated, and the first register or the second register sends the updated data to the IPG circuit module.

[0035] Furthermore, the VA interval event sequence type includes the Vp-As interval event sequence type and the Vp-Ars interval event sequence type, and the VA interval value includes the Vp-As interval or the Vp-Ars interval.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] This application effectively improves the success rate and reliability of AAT testing. By optimizing PVAB and PVARP through an automatic atrial pacing threshold test optimization circuit, it provides a strong guarantee for 1:1 atrioventricular synchronous contraction and also helps to reduce the power consumption of implantable pulse generators, thereby extending their service life.

[0038] Other features and advantages of the present invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0039] The accompanying drawings are incorporated in and form part of this specification, and together with the description serve to explain the principles of the invention.

[0040] 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, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 The flowchart of the optimized method for automatic atrial pacing threshold testing in this application is shown below;

[0042] Figure 2 The PVAB optimization flowchart for this application;

[0043] Figure 3 The PVARP optimization flowchart for this application;

[0044] Figure 4 The circuit block diagram for the automatic atrial pacing threshold test in this application is optimized.

[0045] Figure 5 This is a timing diagram showing how a shortened room retrograde time in an embodiment of this application leads to an error in the AAT test.

[0046] Figure 6This application provides a timing diagram for reducing the PVAB to enable AAT testing in an embodiment of the present application.

[0047] Figure 7 This is a timing diagram showing how an excessively short PVAB in an embodiment of this application causes an AAT test error.

[0048] Figure 8 This application provides a timing diagram for extending PVARP to enable AAT testing in its embodiments.

[0049] Figure 9 In this embodiment of the application, Ap capture failure is identified by extending PVARP timing diagram to identify reverse transmission;

[0050] Figure 10 A timing diagram showing how excessively prolonged PVARP in this embodiment causes AAT tests to fail.

[0051] Figure 11 This is a timing diagram of atrial test pulse Ap capture in an embodiment of this application;

[0052] Figure 12 This is a timing diagram of the atrial test pulse Ap loss capture in an embodiment of this application. Detailed Implementation

[0053] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application as detailed in the claims.

[0054] The abbreviations used in this application are explained as follows:

[0055] Ap: Atrial pacing pulse;

[0056] Vp: Ventricular pacing pulse;

[0057] Ars: Atrial refractory period perception event;

[0058] As: atrial sensation;

[0059] Vs: Ventricular sensing, a type of atrioventricular conduction of the ventricular excitation;

[0060] PVAB: Postventricular atrial blank period;

[0061] PVARP: Postventricular atrium refractory period;

[0062] VA interval: the time interval between a ventricular event and an atrial event, specifically referring to the Vp-As interval or the Vp-Ars interval in this application;

[0063] AV interval: the time interval between an atrial event and a ventricular event, specifically referring to the Ap-Vp interval in this application;

[0064] PMT: Pacemaker-mediated tachycardia;

[0065] AAT: Automatic Atrial Pacing Threshold Test;

[0066] IPG: Implantable Pulse Generator;

[0067] PMT: Pacemaker-mediated tachycardia;

[0068] AAT: Automatic Atrial Pacing Threshold Test;

[0069] IPG: Implantable Pulse Generator.

[0070] See Figure 1 This application proposes an optimized method for automatic atrial pacing threshold testing:

[0071] After the S100 and implantable pulse generator IPG are implanted, the automatic atrial pacing threshold test optimization circuit is started once, and the automatic atrial pacing threshold test is run for the first time to complete the initialization of the first and second registers.

[0072] S1001. During any automatic atrial pacing threshold test, if the PVAB is short (for example, PVAB < 100ms is considered short), and no captured atrial test pulse Ap is detected during the automatic atrial pacing threshold test, then the PVAB is determined to be too short. (Refer to...) Figure 7 , Figure 7 The timing diagram shows that the AAT test fails due to an excessively short PVAB. In this case, the AAT test optimization circuit should be activated to optimize the PVAB and the AAT test should be performed again.

[0073] S1002. During any automatic atrial pacing threshold test, if the PVARP is long (for example, PVARP > 500ms is considered long), and no captured atrial test pulse Ap is detected during the automatic atrial pacing threshold test, then the current PVARP is determined to be too long. (Refer to...) Figure 10 , Figure 10 The timing diagram shows that excessively prolonged PVARP causes AAT test errors. In this case, the AAT test optimization circuit should be activated to optimize PVARP and the AAT test should be performed again.

[0074] S1003. During any automated atrial pacing threshold test, if the PVARP is short (too small), for example, if one of the following two conditions is met:

[0075] The VA event sequence type is Vp-Ars, and in 3 out of 5 VA intervals, the following condition is met: Vp-Ars interval + 10ms > PVARP;

[0076] Three consecutive Vp-As intervals were detected.

[0077] Then it is determined that the current PVARP is too short, refer to Figure 8 , Figure 8 The example demonstrates that an insufficient PVARP value suppresses the Ap pulse during the AAT test, causing the test to be interrupted. In this case, the AAT test optimization circuit should be activated to optimize the PVARP value, and the AAT test should be performed again.

[0078] Based on the above embodiments of this application, for a fixed user, the conduction time of atrioventricular retrograde conduction is relatively stable, and the interference window time of the far-field signal generated by the ventricular pathway Vp on the atrial pathway is also stable. Therefore, under normal circumstances, in Figure 1 Once the AAT test optimization circuit is initiated at point I and the first and second registers are updated, it will not be initiated again. In some specific embodiments, if the conduction time of atrioventricular retrograde conduction changes significantly, or if the interference window time of the far-field signal generated by the ventricular channel Vp on the atrial channel is significantly prolonged, the AAT test optimization circuit may be initiated again at point II or III and the first or second register may be updated.

[0079] See Figure 2 Here is the PVAB optimization flowchart for this application:

[0080] S201. Detect the current ECG rhythm, increase the pacing program by 10 ppm, read the data from the first register and assign a value to PVAB, with the initial value of PVAB being 50 ms. Based on the atrial sensing event type (As or Ars) identified by the implanted pulse generator IPG, write the VA interval event sequence type (Vp-As interval or Vp-Ars interval) into the third register;

[0081] S202. Write the VA interval value recorded by the timer into the fourth register;

[0082] S203. If the VA interval event sequence type written to the third register is Vp-Ars, then execute S204; otherwise, execute S206.

[0083] S204. Read the first register, set its initial value to 50ms, and record it as the current PVAB. The comparator compares the PVAB in the first register with the VA interval in the fourth register. The counter accumulates the number of comparisons. In a specific example, if 3 out of the 5 recorded VA intervals meet the following condition:

[0084] VA interval <PVAB+10ms,

[0085] If so, execute S205; otherwise, execute S206.

[0086] S205, PVAB increments by 5ms and is written to the first register, then jumps to S201 to continue PVAB optimization.

[0087] S206 and PVAB are increased by 10ms and written to the first register to complete the PVAB optimization.

[0088] It should be noted that if the VA event sequence type is Vp-Ars, and the following conditions are met 3 out of 5 VA intervals:

[0089] Vp-Ars interval <PVAB+10ms,

[0090] If the current PVAB is determined to be too short, the PVAB value is increased by 5ms, and PVAB optimization continues; otherwise, the PVAB value is increased by 10ms. It should be noted that the 10ms here is a safety margin to ensure that the PVAB is large enough to avoid the adverse effects of far-field perception on AAT testing, and the first register is updated to complete the PVAB optimization.

[0091] See Figure 3 Here is the PVARP optimization flowchart for this application:

[0092] S301. Detect the current ECG rhythm and increase the pacing program by 10 ppm. Read the data from the second register and assign a value to PVARP. The initial value of PVARP is the PVARP setting value in normal operating mode. Based on the atrial sensing event type (As or Ars) identified by the pulse generator, write the VA interval event sequence type (Vp-As interval or Vp-Ars interval) into the third register.

[0093] S302. Write the VA interval value recorded by the timer into the fourth register;

[0094] S303. If the VA interval event sequence type written to the third register is Vp-Ars, then go to S304; otherwise, go to S305.

[0095] S304. Read the second register, initialize it to the PVARP setting value in normal working mode, and record it as the current PVARP. The comparator compares the PVARP in the second register with the VA interval in the fourth register. If 3 out of the 5 recorded VA intervals meet the following condition:

[0096] VA interval +10ms <PVARP,

[0097] If so, execute S306; otherwise, execute S307.

[0098] S305. If the counter records that the Vp-As event sequence type has not appeared three times consecutively, then proceed to S301; otherwise, proceed to S307.

[0099] S306 and the second register remain unchanged, so there is no need to optimize PVARP.

[0100] S307, PVARP = VA interval + 50ms, and write to the second register to complete the PVARP optimization.

[0101] It should be noted that if one of the following two conditions is met:

[0102] The VA event sequence type is Vp-Ars, and it satisfies the following conditions in 3 out of 5 VA intervals:

[0103] Vp-Ars interval +10ms > PVARP

[0104] Three consecutive Vp-As intervals were detected.

[0105] If the current PVARP interval is too short, the PVARP interval will be increased by 50ms to complete the PVARP optimization; otherwise, PVARP optimization is not required.

[0106] In addition, a protection mechanism is set up for the optimization of PVARP, which limits the maximum value of PVARP after optimization to satisfy the following relationship:

[0107] Optimized PVARP < base interval - AV interval - 300ms.

[0108] The basic interval and AV interval can be obtained directly from the implantable pulse generator (IPG). 300ms is a safety margin to prevent excessive PVARP from causing the subsequent atrial test pulse Ap to fall into the myocardial refractory period, resulting in errors in the AAT test.

[0109] In a second aspect, embodiments of this application provide an automated atrial pacing threshold testing optimization method and testing optimization circuit, which... Figure 4 It can be seen that the circuit includes a timer 200, a register 300, a comparator 400, and a counter 500.

[0110] The timer starts after the pacing circuit delivers Vp and completes one timing cycle after the sensing circuit detects atrial sensing (including As and Ars).

[0111] The first register 301 is used to record the optimized PVAB value, and its initial value is set to 50ms.

[0112] The second register 302 is used to record the optimized PVARP value, and its initial value is the IPG initialization setting value.

[0113] The third register 303 is used to record the VA interval event sequence type, including two event sequence types: Vp-As interval and Vp-Ars interval.

[0114] The fourth register 304 is used to record the VA interval value, namely the Vp-As interval or the Vp-Ars interval.

[0115] Comparator 400 compares the VA interval value recorded in the fourth register 304 with the value in the first register 301 or the second register 302.

[0116] Counter 500 accumulates the number of comparisons and updates either the first register 301 or the second register 302 after reaching a preset target value. The updated data of the first register 301 or the second register 302 is sent to the IPG, thereby completing PVAB and PVARP optimization.

[0117] Based on the above embodiments of this application, the main purpose of this circuit is to optimize the postventricular atrial blank period (PVAB) and the postventricular atrial refractory period (PVARP). Furthermore, the pacing circuit unit and sensing circuit unit in the figure are fundamental circuit components of the implantable pulse generator (IPG).

[0118] In some embodiments of this application, the timer starts after the pacing circuit delivers the ventricular pacing pulse Vp and completes one timing cycle after the sensing circuit detects atrial sensing (including As and Ars). The first register records the optimized PVAB value, initialized to 50ms. The second register records the optimized PVARP value, initialized to the IPG's initialization setting. The third register records the VA interval event sequence type, including both Vp-As and Vp-Ars intervals. The fourth register records the VA interval value, either Vp-As or Vp-Ars. A comparator compares the VA interval value recorded in the fourth register with the value in the first or second register. A counter accumulates the number of comparisons and, upon reaching a preset target value, updates the first or second register. The updated data in the first or second register is sent to the IPG, thus completing the PVAB and PVARP optimization.

[0119] Based on the above embodiments of this application, refer to Figure 11 and Figure 5 , Figure 11 This is a timing diagram of the atrial pulse Ap capture loss during atrial testing. Figure 5 This is a timing diagram showing that the shortened atrioventricular retrograde time caused the AAT test to fail, compared to... Figure 11 , Figure 5 When the atrioventricular retrograde conduction time generated by the central ventricular pacing pulse Vp is shortened, the P wave generated by retrograde conduction falls into the postventricular atrial blank period PVAB, making the implantable pulse generator IPG unable to recognize the signal. As a result, the uncaptured Ap pulse is judged as captured, leading to an error in the automatic atrial pacing threshold test (AAT).

[0120] Based on the above embodiments of this application, refer to Figure 6 , Figure 6 This refers to the timing diagram where reducing the PVAB makes the AAT test effective. When the atrioventricular retrograde conduction time generated by Vp is shortened, the PVAB can be appropriately reduced so that the P wave generated by retrograde conduction falls outside the PVAB. In this case, the IPG can identify it as an Ars event, and the AAT test can proceed normally. However, the implantable pulse generator (IPG) itself cannot directly adjust the postventricular atrial blank PVAB value to the appropriately reduced postventricular atrial blank PVAB. Furthermore, an excessively short postventricular atrial blank PVAB will cause the atrial pathway to identify the far-field signal generated by the ventricular pacing pulse Vp in the ventricular pathway as an Ars event. (Refer to...) Figure 7 , Figure 7 This is a timing diagram showing how an excessively short postventricular atrial blanking interval (PVAB) causes errors in the AAT test. In this case, regardless of whether the Ap pulse can capture the myocardium, the IPG will classify it as a failure to capture, leading to an AAT test error. To optimize this, based on the AAT test optimization circuit, the PVAB can be initialized to 50ms and gradually increased in 5ms increments. A suitable PVAB setting should be small, yet large enough to avoid misidentification of far-field signals by the atrial channel.

[0121] It should be noted that, in some specific embodiments, the atrioventricular retrograde conduction duration generated by the ventricular pacing pulse Vp is close to the time window duration of the far-field signal generated by the ventricular pacing pulse Vp. In this case, regardless of the setting of the post-ventricular atrial blank period (PVAB), the implantable pulse generator (IPG) cannot correctly identify the P wave generated by retrograde conduction as Ars. Therefore, the AAT test cannot be performed normally. However, this situation is relatively rare. Generally, the atrioventricular retrograde conduction duration generated by Vp is significantly longer than the time window duration of the far-field signal generated by Vp. In this case, during the AAT test, the implantable pulse generator (IPG) will not detect the Ap pulse that can capture myocardium and will indicate a test failure, thus not outputting incorrect test results.

[0122] Based on the above embodiments of this application, and referring to... Figure 12 and Figure 8 , Figure 12 This is a timing diagram of the atrial pulse Ap capture loss during atrial testing. Figure 8 It is a timing diagram that extends PVARP to make AAT testing effective, compared to Figure 12 , Figure 8 When the atrioventricular conduction time of the ventricular pacing pulse Vp becomes longer, the P wave generated by retrograde conduction falls outside the postventricular atrial refractory period PVARP. Although the implantable pulse generator (IPG) can correctly identify this signal, continuous atrioventricular conduction (As) events will continuously suppress the delivery of the atrial pacing pulse Ap, thus causing the AAT test to be interrupted. It should be noted that the continuous suppression of atrial pacing pulse Ap delivery by continuous atrioventricular conduction (As) events is determined by the basic timing characteristics of the IPG. (Reference) Figure 9 , Figure 9 To capture Ap in this embodiment of the application, the timing diagram of retrograde conduction is identified by extending PVARP. When the atrioventricular retrograde conduction time generated by the ventricular pacing pulse Vp becomes longer, the postventricular atrial refractory period PVARP can be appropriately extended so that the P wave generated by retrograde conduction falls within the postventricular atrial refractory period PVARP. The implantable pulse generator (IPG) can then identify this as an Ars event, and the AAT test can proceed normally. However, the implantable pulse generator (IPG) itself cannot directly adjust the PVARP value to the appropriately extended postventricular atrial refractory period PVARP. Furthermore, an excessively long postventricular atrial refractory period PVARP may cause the identified Ars event to be too close to the subsequently delivered Ap, resulting in the Ap falling into the myocardial refractory zone. (Refer to...) Figure 10 , Figure 10 This is a timing diagram illustrating how excessively prolonged post-ventricular atrial refractory period (PVARP) causes AAT (Atrial Acquisition Test) errors. In this case, regardless of whether the amplitude of the atrial pacing pulse Ap exceeds the pacing threshold, the implantable pulse generator (IPG) will interpret it as a loss of capture, leading to AAT test errors. In this situation, the VA interval value can be acquired based on the optimized circuitry of the AAT test to optimize the post-ventricular atrial refractory period (PVARP). A suitable post-ventricular atrial refractory period (PVARP) setting should be a relatively large value, large enough to avoid suppression of the Ap test pulse when the atrioventricular retrograde conduction time is large, but not too large to avoid subsequent Ap test pulses falling into the myocardial refractory zone.

[0123] It should be noted that, to maintain a 1:1 atrioventricular synchronization, the implantable pulse generator (IPG) employs a series of complex timing periods. For the atrial pathway, the two most critical timing periods are the postventricular atrial blank period (PVAB) and the postventricular atrial refractory period (PVARP). The PVAB is the blank period for atrial sensing after a ventricular event (including Vs ventricular sensing and Vp ventricular pacing pulses). During this timing period, atrial sensing is closed, thus preventing far-field signals generated by ventricular events in the atrial pathway from affecting atrial sensing. The PVARP is the refractory period for atrial sensing after a ventricular event (including Vs and Vp). Atrial events sensed during this timing period are marked as Ars and do not affect the basic timing of the IPG, preventing pacemaker-mediated tachycardia (PMT) caused by atrioventricular retrograde conduction.

[0124] In some embodiments of this application, the user's basic heart rhythm characteristics are identified and recorded, and PVAB and PVARP are optimized using a specific algorithm, based on which the AAT test is completed. In normal operating mode, the implantable pulse generator (IPG) uses preset conventional post-ventricular atrial blank period (PVAB) and post-ventricular atrial refractory period (PVARP), which is more conducive to the coordination between the IPG and the user's own rhythm. However, during the automatic atrial pacing threshold test (AAT), the optimized post-ventricular atrial blank period (PVAB) and post-ventricular atrial refractory period (PVARP) obtained using the method of this application take into account the possibility of atrioventricular retrograde conduction during the AAT test, further improving the success rate and reliability of the AAT test.

[0125] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0126] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. An optimized method for automatic atrial pacing threshold testing, characterized in that, Said method comprises the following steps: starting an automatic atrial pacing threshold testing optimization circuit, completing initialization of PVAB in a first register and PVARP in a second register, and starting an automatic atrial pacing threshold test; during the testing process: if PVAB is less than a set value x1 and no captured atrial pacing pulse Ap is detected during the automatic atrial pacing threshold test, starting the automatic atrial pacing threshold testing optimization circuit, updating the first register after optimizing PVAB; if PVARP is excessively large and no captured atrial pacing pulse Ap is detected during the automatic atrial pacing threshold test, or PVARP is excessively small, starting the automatic atrial pacing threshold testing optimization circuit, updating the second register after optimizing PVARP; wherein, the excessively large means that PVARP is greater than a set value x2; the determination method for the excessively small is: when the VA event sequence type is Vp-Ars, and 3 out of 5 VA intervals satisfy Vp-Ars interval + 10ms > PVARP, or Vp-As intervals are continuously detected for 3 times, PVARP is determined to be excessively small; if PVAB is greater than or equal to the set value x1 and PVARP is not excessively large or excessively small, the automatic atrial pacing threshold test is completed.

2. The method for optimizing automatic atrial pacing threshold testing according to claim 1, characterized in that, Said optimization of PVAB comprises the following steps: detecting the current cardiac electrophysiological rhythm through an IPG circuit module, reading data in the first register and assigning a value to PVAB, setting an initialized value of PVAB, writing the VA interval event sequence type into the third register according to the atrial sensing event type identified by the pulse generator, and writing the VA interval value recorded by a timer into the fourth register; comparing, by a comparator, PVAB in the first register with the VA interval in the fourth register, accumulating, by a counter, the number of comparisons stored in the comparator, if 3 / 5 probability that VA interval < PVAB + b1 is satisfied in the VA intervals, determining that PVAB is currently added by a1, and continuing optimization of PVAB; otherwise, adding b1 to PVAB, updating the first register, and completing optimization of PVAB, wherein a1 is a first step size and b1 is a first safety margin.

3. The method for optimizing an automatic atrial pacing threshold test according to claim 1, characterized in that, Said optimization of PVARP comprises the following steps: detecting the current cardiac electrophysiological rhythm through an IPG circuit module, reading data in the second register and assigning a value to PVARP, setting an initialized value of PVARP, writing the VA interval event sequence type into the third register according to the atrial sensing event type identified by the pulse generator, and writing the VA interval value recorded by a timer into the fourth register; comparing, by a comparator, PVARP in the second register with the VA interval in the fourth register, if 3 / 5 probability that VA interval + b2 < PVARP is satisfied in the VA intervals, determining that PVARP is currently added by a2, and continuing optimization of PVARP; otherwise, adding b2 to PVARP, updating the second register, and completing optimization of PVARP, wherein a2 is a second step size and b2 is a second safety margin.

4. The method for optimizing automatic atrial pacing threshold testing according to claim 3, characterized in that, a protection mechanism is provided for the step of optimizing PVARP, and the optimized PVARP in the protection mechanism satisfies: Optimized PVARP < basic interval - AV interval - a3, The basic interval and AV interval are both obtained through IPG, and a3 is the third safety margin.

5. The method for optimizing automatic atrial pacing threshold testing according to claim 2, characterized in that, The initial value of the first step length a1 is 50ms, and the first step length a1 is gradually increased in 5ms increments to perform PVAB optimization.

6. The method for optimizing automatic atrial pacing threshold testing according to claim 2, characterized in that, The first safety margin b1 is set to 10ms.

7. The method for optimizing automatic atrial pacing threshold testing according to claim 3, characterized in that, The initial value of the second step size a2 is the PVARP setting value under normal working mode, and PVARP optimization is performed. The second safety margin b2 is set to 10ms.

8. The method for optimizing automatic atrial pacing threshold testing according to claim 4, characterized in that, The third safety margin a3 is set to 300ms.

9. An optimized circuit for automatic atrial pacing threshold testing, using the method described in any one of claims 1 to 8, characterized in that, The test optimization circuit includes an IPG circuit module (100), a timer (200), a register (300), a comparator (400), and a counter (500); The register (300) includes a first register (301), a second register (302), a third register (303), and a fourth register (304); the IPG circuit module (100) includes a pacing circuit unit (101) and a sensing circuit unit (102). The pacing circuit unit (101) is electrically connected to the timer (200) and is used to start the timer (200) when Vp is delivered; The sensing circuit unit (102) is electrically connected to the timer (200) and is used to send a signal to the timer (200) after sensing As and Ars, so that the timer (200) completes one timing cycle; The first register (301) is electrically connected to the IPG circuit module (100) and the comparator (400) respectively, and is used to record the optimized PVAB value; The second register (302) is electrically connected to the IPG circuit module (100) and the comparator (400) respectively, and is used to record the optimized PVARP value; The third register (303) is electrically connected to the timer (200) and the comparator (400) respectively, and is used to record the VA interval event sequence type; The fourth register (304) is electrically connected to the timer (200) and the comparator (400) respectively, and is used to record the VA interval value; The comparator (400) is electrically connected to the counter (500) and is used to compare the VA interval value recorded in the fourth register (304) with the optimized PVAB value recorded in the first register and the PVARP value recorded in the second register. The counter (500) is electrically connected to the first register (301) and is used to accumulate the number of comparisons of the comparator (400). After the number of comparisons reaches a preset target, the first register (301) or the second register (302) is updated. The first register (301) or the second register (302) sends the updated data to the IPG circuit module.

10. An automatic atrial pacing threshold testing optimization circuit according to claim 9, wherein the VA interval event sequence type includes the Vp-As interval event sequence type and the Vp-Ars interval event sequence type, and the VA interval value includes the Vp-As interval or the Vp-Ars interval.

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