Dynamic switching between CRT and MSP

Abstract

Systems and methods are disclosed for controlling transitions of a stimulation circuit configured to generate first and second stimulation signals in different respective first and second stimulation patterns between the different respective first and second stimulation patterns using patient metrics, the patient metric is determined using received physiological information of the patient, the physiological information including at least one of thoracic impedance information or breathing information from a first time period.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 420,243, filed on December 5, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention generally relates to medical devices, and more particularly to dynamically switching between cardiac resynchronization therapy (CRT) and multi - site pacing (MSP) using a patient's physiological information for therapy delivery. Background Art

[0004] Heart failure (HF) is a decrease in the heart's ability to deliver blood sufficient to meet the body's needs. Patients with heart failure typically present with an enlarged heart and weakened myocardium, resulting in reduced contractility and poor cardiac output. Signs of heart failure include pulmonary congestion, edema, dyspnea, etc. Heart failure is usually a chronic disease but can also occur suddenly, affecting the left side, right side, or both sides of the heart. The causes of heart failure include coronary artery disease, myocardial infarction, hypertension, atrial fibrillation, valvular heart disease, alcoholism, infection, cardiomyopathy, or one or more other conditions that reduce the heart's pumping efficiency.

[0005] Medical devices, including implantable, subcutaneous, wearable, or one or more other types of medical devices, etc., can monitor, detect, or treat various conditions, including heart failure, atrial fibrillation, etc. Medical devices can include sensors for sensing physiological information from a patient, and one or more circuits for using the sensed physiological information to detect one or more physiological events or transmit the sensed physiological information or the detected physiological events to one or more remote devices. In addition, medical devices can be configured to provide electrical stimulation or one or more other therapies or treatments to a patient, such as to improve cardiac function, etc.

[0006] Frequent patient monitoring can provide early detection of patient deterioration, including worsening heart failure or atrial fibrillation. Accurate identification of patients or patient groups at elevated risk of future adverse events can control the mode or feature selection or resource management of one or more medical devices, control notifications or messages to various users associated with a particular patient or patient group in a connected system, organize or schedule doctor or patient contacts or treatments, or prevent or reduce patient hospitalizations. Proper identification and risk management of patient deterioration can avoid unnecessary medical interventions, extend the useful life of medical devices, and reduce healthcare costs. Additionally, in cases where different operating modes, functions, or therapies are available, correctly monitoring, detecting, and identifying patient status (including patient improvement or deterioration) and modifying one or more medical device functions accordingly can improve medical device efficiency, such as by reducing unnecessary resource consumption, thereby extending the useful life of mobile medical devices. Summary of the Invention

[0007] Systems and methods for controlling transitions of a stimulation circuit are disclosed, the stimulation circuit being configured to generate first and second stimulation signals in different respective first and second stimulation modes using a patient metric, the patient metric being determined using received physiological information of a patient, the physiological information including at least one of thoracic impedance information or respiratory information from a first time period.

[0008] Examples (such as "Example 1") of a subject matter (such as a medical device system) can include: a stimulation circuit configured to generate first and second stimulation signals in different respective first and second stimulation modes, the first and second stimulation signals being configured to be provided to a patient's heart; a signal receiver circuit configured to receive physiological information of the patient, the physiological information including at least one of thoracic impedance information or respiratory information; and an evaluation circuit configured to control transitions of the stimulation circuit between the first and second stimulation modes, including determining a patient metric using the received physiological information from the first time period and controlling transitions of the stimulation circuit between the first and second stimulation modes based on the determined patient metric.

[0009] In Example 2, the subject matter according to Example 1 can optionally be configured such that the first time period occurs while the stimulation circuit is in the first stimulation mode, and controlling transitions between the first and second stimulation modes includes: controlling the transition from the first stimulation mode to the second stimulation mode based on the determined patient metric.

[0010] In Example 3, the subject matter described in any one or more of Examples 1 to 2 may optionally be configured such that the evaluation circuit is configured to control the implementation of the first stimulation mode at a first time, wherein a first time period occurs after the first time, and the control for the stimulation circuit to transition from the first stimulation mode to the second stimulation mode includes occurring at a second time after the first time period.

[0011] In Example 4, the subject matter described in any one or more of Examples 1 to 3 may optionally be configured such that the control for the stimulation circuit to transition from the first stimulation mode to the second stimulation mode at the second time includes comparing the determined patient metric with a threshold, and if the determined patient metric exceeds the first threshold, transitioning the stimulation circuit from the first stimulation mode to the second stimulation mode, and if the determined patient metric does not exceed the first threshold, retaining the stimulation circuit in the first stimulation mode.

[0012] In Example 5, the subject matter described in any one or more of Examples 1 to 4 may optionally be configured such that the first stimulation mode includes a cardiac resynchronization therapy (CRT) mode that is configured to generate a stimulation signal to be delivered to at least one of a single electrode in a first chamber of the heart or a single electrode in a second chamber of the heart, and the second stimulation mode includes a multisite pacing (MSP) mode that is configured to generate a stimulation signal to be delivered to multiple electrodes in one of the first or second chambers of the heart.

[0013] In Example 6, the subject matter described in any one or more of Examples 1 to 5 may optionally be configured such that the CRT mode is configured to generate a biventricular pacing signal to be delivered to a single electrode in each of the right ventricle and the left ventricle of the heart, and the MSP therapy mode is configured to generate a stimulation signal to be delivered to multiple electrodes in the left ventricle of the heart.

[0014] In Example 7, the subject matter described in any one or more of Examples 1 to 6 may optionally be configured such that the first time period occurs when the stimulation circuit is in the second stimulation mode, and the control for the transition between the first and second stimulation modes includes: controlling the transition from the second stimulation mode to the first stimulation mode based on the determined patient metric.

[0015] In Example 8, the subject matter described in any one or more of Examples 1 to 7 may optionally be configured such that the thoracic impedance information includes intrathoracic impedance (ITTI) information, and the respiratory information includes rapid shallow breathing index (RSBI) information.

[0016] In Example 9, the subject matter according to any one or more of Examples 1 to 8 may optionally be configured such that the evaluation circuit is configured to determine a patient metric as a function of ITTI information and RSBI information.

[0017] In Example 10, the subject matter according to any one or more of Examples 1 to 9 may optionally be configured such that the respiratory information includes a measured value of tidal volume (TV).

[0018] Examples (e.g., "Example 11") of the subject matter (e.g., a method) may include: generating first and second stimulation signals using a stimulation circuit in different respective first and second stimulation modes, the first and second stimulation signals being configured to be provided to a patient's heart, receiving physiological information of the patient (including at least one of thoracic impedance information or respiratory information) using a signal receiver circuit, and controlling, using an evaluation circuit, a transition between the first and second stimulation modes, which includes determining a patient metric using the physiological information received from a first time period and controlling the transition between the first stimulation mode and the second stimulation mode based on the determined patient metric.

[0019] In Example 12, the subject matter according to any one or more of Examples 1 to 11 may optionally be configured such that the first time period occurs when the stimulation circuit is in the first stimulation mode, and controlling the transition between the first and second stimulation modes includes: controlling the transition from the first stimulation mode to the second stimulation mode based on the determined patient metric.

[0020] In Example 13, the subject matter according to any one or more of Examples 1 - 12 may optionally include a control implementation for controlling the first stimulation mode at a first time, where the first time period occurs after the first time, and where controlling the stimulation circuit to transition from the first stimulation mode to the second stimulation mode occurs at a second time after the first time period.

[0021] In Example 14, the subject matter according to any one or more of Examples 1 to 13 may optionally be configured such that controlling the stimulation circuit to transition from the first stimulation mode to the second stimulation mode at the second time includes comparing the determined patient metric with a threshold, and if the determined patient metric exceeds a first threshold, transitioning the stimulation circuit from the first stimulation mode to the second stimulation mode, and if the determined patient metric does not exceed the first threshold, retaining the stimulation circuit in the first stimulation mode.

[0022] In Example 15, the subject matter described in any one or more of Examples 1 to 14 may optionally be configured such that the first stimulation mode includes a cardiac resynchronization therapy (CRT) mode that is configured to generate a stimulation signal to be delivered to at least one of a single electrode in a first chamber of the heart or a single electrode in a second chamber of the heart, and the second stimulation mode includes a multisite pacing (MSP) mode that is configured to generate a stimulation signal to be delivered to a plurality of electrodes in one of the first or second chambers of the heart.

[0023] In Example 16, the subject matter described in any one or more of Examples 1 to 15 may optionally be configured such that the CRT mode is configured to generate a biventricular pacing signal to be delivered to a single electrode in each of the right and left ventricles of the heart, and the MSP therapy mode is configured to generate a stimulation signal to be delivered to a plurality of electrodes in the left ventricle of the heart.

[0024] In Example 17, the subject matter described in any one or more of Examples 1 to 16 may optionally be configured such that a first time period occurs when the stimulation circuit is in the second stimulation mode, and controlling the transition between the first and second stimulation modes includes: controlling the transition from the second stimulation mode to the first stimulation mode based on the determined patient metric.

[0025] In Example 18, the subject matter described in any one or more of Examples 1 to 17 may optionally be configured such that the thoracic impedance information includes intrathoracic impedance (ITTI) information, and the respiratory information includes rapid shallow breathing index (RSBI) information.

[0026] In Example 19, the subject matter described in any one or more of Examples 1 to 18 may optionally be configured such that determining the patient metric includes being performed according to a function of the ITTI information and the RSBI information.

[0027] In Example 20, the subject matter described in any one or more of Examples 1 to 19 may optionally be configured such that the respiratory information includes a measured value of tidal volume (TV).

[0028] In Example 21, the subject matter (such as a system or device) may optionally combine any part or any combination of any part described in any one or more of Examples 1 to 20 to include a "device" or at least one "non-transitory machine-readable medium" for performing any part described in any one or more of the functions or methods according to Examples 1 to 20, the non-transitory machine-readable medium including instructions that, when executed by a machine, cause the machine to perform any part described in any one or more of the functions or methods according to Examples 1 to 20.

[0029] The present invention content aims to provide an overview of the subject matter of this patent application. It is not intended to provide an exclusive or exhaustive interpretation of the present disclosure. A detailed description is included to provide further information about this patent application. Other aspects of the present disclosure will be apparent to those skilled in the art upon reading and understanding the following detailed description and referring to the accompanying drawings, each of which should not be regarded as restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In the drawings, which are not necessarily to scale, like numeral designations may describe like components in different views. Like numeral designations with different letter suffixes may represent different instances of like components. By way of example and not limitation, the drawings generally illustrate various embodiments discussed in this invention document.

[0031] Figure 1 An example process of using the determined patient parameters to control transitions between treatment modes is shown.

[0032] Figure 2 An example process of determining one or more patient metrics before final selection or implantation of a second medical device is shown.

[0033] Figure 3A -C shows example heart sound information of a patient during a first time period after implantation of a CRT device.

[0034] Figure 4A -C shows example RSBI information of a patient during a first time period after implantation of a CRT device.

[0035] Figure 5 The determined odds ratio of physiological information associated with the response to CRT is shown.

[0036] Figure 6 An exemplary implantable medical device (IMD) electrically coupled to the heart is shown.

[0037] Figure 7 An exemplary medical device system is shown.

[0038] Figure 8 An exemplary patient management system is shown.

[0039] Figure 9 A block diagram of an example machine on which any one or more of the techniques discussed herein may be executed is shown. DETAILED DESCRIPTION

[0040] Medical devices can be implanted into a patient's body or otherwise positioned on or around the patient to monitor the patient's physiological information (such as heart sound information, respiratory information (e.g., respiration rate (RR), tidal volume (TV), rapid shallow breathing index (RSBI), etc.), impedance information (e.g., intrathoracic impedance (ITTI)), pressure information, electrocardiogram information (e.g., heart rate), body activity information, or other physiological information or one or more other physiological parameters of the patient), or to provide electrical stimulation or one or more other therapies or treatments to optimize or control the contraction of the patient's heart. For example, a medical device can include one or more implantable medical devices (IMDs), such as a cardiac resynchronization therapy (CRT) device, etc., which is configured to receive cardiac electrical information from one or more electrodes located within, on, or near the heart (such as coupled to one or more leads and located in one or more chambers of the heart or in the vasculature near one or more chambers of the heart or otherwise attached to or in contact with the heart), and in some examples, provide electrical stimulation to the heart.

[0041] Stimulation signals can be generated and provided to one or more chambers of the heart (e.g., often two or more of the right ventricle (RV), left ventricle (LV) (e.g., generally via the cardiac vascular system), or right atrium (RA), etc.) to improve heart function, such as improving the contraction coordination between different chambers of the heart (e.g., the right ventricle and the left ventricle, the right atrium and the right ventricle, etc.), or otherwise improving cardiac output or efficiency. However, different treatment modes can provide different therapies, which have different power and resource requirements and different efficacy for different corresponding patients. Patients can use multiple treatment modalities, but not all patients can receive the optimal medical device, treatment mode, or treatment settings.

[0042] Among other things, the inventors have recognized that, in some examples, systems and methods for using physiological information from a corresponding patient to determine which of multiple treatments may be more effective for the corresponding patient before providing one or more treatment modes, or before switching from a first treatment mode to a second treatment mode.

[0043] Conventional CRT includes generating a stimulation signal and applying it to one or more chambers of the heart to improve the contraction coordination of different chambers, or alternatively to improve cardiac output or efficiency. CRT can include biventricular pacing of the right and left ventricles of the heart, but can also include single-chamber pacing (e.g., right ventricular pacing, left ventricular pacing, etc.), sensing or pacing in one or more other chambers or combinations of chambers, etc. The timing of the stimulation signal during the cardiac cycle or relative to one or more cardiac events typically varies according to multiple factors, which include lead or electrode placement, propagation of the stimulation signal through tissue, stimulation amplitude, etc.

[0044] In contrast, multisite pacing (MSP) (or multiple-site pacing) therapy generally refers to applying one or more stimulation signals to multiple electrodes (e.g., two or more) in or near a first chamber (e.g., generally the left ventricle, but also the right ventricle, right atrium, or combinations thereof in some examples) for a single cardiac cycle. During MSP therapy, the same or different stimulation signals can be applied to different electrodes in or near the first chamber at the same time, different times (e.g., delayed), or combinations thereof for a single cardiac cycle.

[0045] Some heart failure patients respond to (e.g., benefit from) MSP therapy but not to CRT. Other patients do not respond either. Pacing therapy is frequently evaluated to ensure that the applied pacing therapy provides some benefit to the patient, to determine whether the pacing therapy should be adjusted, or to determine whether the pacing therapy should be switched. For example, the study titled "Usefulness of Multisite Ventricular Pacing in Nonresponders to Cardiac Resynchronization Therapy" published by Samir Saba et al. in the American Journal of Cardiology on February 1, 2022 (hereinafter referred to as the "Saba study") found that 25% to 40% of heart failure patients with myocardial dysfunction did not respond to conventional CRT in the assessment at 6 months after implantation, but also found that more than half (51.3%) of the CRT non-responders at 6 months subsequently responded to MSP therapy in the left ventricle at 12 months after implantation. The assessment in the Saba study was based on the assessment of patient mortality, incidence of heart failure events, global patient assessment, and NYHA heart failure general classification.

[0046] Although the transition from CRT to MSP therapy in the left ventricle is physiologically largely uncomplicated, switching from conventional CRT to MSP therapy may impose at least some cardiac stress and also requires additional resources from the implantable medical device. In some estimates, implementing MSP therapy in a device capable of both MSP therapy and CRT shortens the estimated lifespan of the device by 11 - 13%. Even a single six - month evaluation of MSP therapy on an IMD has a relatively large and often unnecessary impact on the service life of the IMD.

[0047] The inventors have recognized that, among other things, certain physiological information sensed from a patient over one or more time periods can be used to determine one or more MSP response metrics, and such one or more determined MSP response metrics can be used to provide an alert or notification, or otherwise control the transition between different medical device modes (e.g., a first stimulation mode, a second stimulation mode, etc.), which in some examples includes for: (1) controlling the transition from a non - MSP therapy mode to an MSP therapy mode; (2) controlling the transition from an MSP therapy mode to a non - MSP therapy mode; or (3) enabling or disabling the MSP therapy mode.

[0048] In addition, the inventors have recognized that specific physiological information sensed from a patient after implementing a stimulation mode can be used to determine an MSP response metric configured to determine an indication of the predicted patient response to the stimulation mode, such that in some examples, the stimulation mode can be evaluated without entering the stimulation mode. In particular, the inventors have recognized that specific physiological information or a combination of physiological information can be determined to evaluate a stimulation mode or predict a positive patient response to a specific stimulation mode, such as using the response to another stimulation mode, etc. In an example, physiological information sensed or detected during the CRT mode can be used to determine whether a patient is likely to respond (e.g., benefit) from the MSP therapy mode before implementing or enabling the MSP therapy mode.

[0049] In an example, the inventors have recognized that, among other things, one or more of impedance information (e.g., ITTI) and respiratory information (e.g., RSBI), or a combination thereof, over one or more time periods (e.g., a 60 - day time period, a 150 - day time period, etc.) can be used to determine an indication that a patient will respond to the MSP therapy mode before implementing or enabling the MSP therapy mode. An example is provided below, namely Equation (1).

[0050] p(MSP response )∝(α×ITTI)+(β×RSBI)(1)

[0051] In Equation (1), p(MSP response) is a patient metric (e.g., MSP response metric), ITTI is a measurement of the patient's intrathoracic impedance, RSBI is the ratio of the measurement of the patient's respiratory rate (RR) or frequency to the measurement of the tidal volume (TV) (e.g., RR / TV, etc.), and α and β are variables. In other examples, the patient metric can be determined using only one of the ITTI or RSBI information, or as a different function of one or more such physiological parameters in combination with one or more other physiological parameters. Using physiological information from a period of time in a treatment mode prior to implementing the MSP treatment mode (e.g., from within a conventional CRT mode), the inventors were able to determine a positive MSP response using Equation (1) and a threshold (TH), where the area under the ROC curve was 0.8309 and the confidence interval was 95%. Once in the MSP treatment mode, the inventors were able to determine a positive MSP response using Equation (1) and a threshold (TH), where the area under the ROC curve was 0.78527 and the confidence interval was 95%. Such determination is highly sensitive.

[0052] Figure 1 An example process 100 for controlling transitions between treatment modes using the determined patient parameters is shown. Based on training data, the patient metric can be determined with a true positive rate of 50% and a true negative rate of 0%. In some examples, prior to transitioning to the MSP treatment mode, a highly sensitive determination may be required, such as by adjusting Equation (1) or one or more thresholds, to conserve medical device resources and avoid unnecessary cardiac stress associated with the transition.

[0053] At step 101, for example, in some examples, the CRT mode can be implemented at a first time. Although described herein as starting from implementing the CRT mode, in other examples, the process can start from one or more other treatment modes, or from a monitoring mode without treatment. In some examples, the stimulation circuit can generate and provide one or more stimulation signals in one or more stimulation modes, and the evaluation circuit can be configured to control the stimulation circuit to, for example, adjust one or more parameters or transitions between different treatment modes, etc.

[0054] At step 102, physiological information can be received from one or more sensors, such as using a signal receiver circuit. The received physiological information can include, but is not limited to, patient ITTI information, patient RSBI information, or one or more other types of patient information, such as described herein.

[0055] At step 103, the patient metric (such as one or more MSP response metrics) can be determined based on the received physiological information, such as described with respect to Equation (1) or otherwise described herein, and in some examples using the evaluation circuit to determine.

[0056] At step 104, the determined patient metric can be compared with a threshold (TH), such as using an evaluation circuit. If the determined patient metric exceeds the threshold, an MSP treatment mode can be implemented at step 105 (e.g., transitioning from a CRT mode to an MSP treatment mode), and the process can return to step 102. In other examples, instead of implementing the MSP treatment mode, an indication to implement the MSP treatment mode can be provided, such as providing the indication to a clinician or one or more other machines or processes via a notification or alert, etc. If the determined patient metric does not exceed the threshold, the MSP treatment mode can remain off at step 106, and the process can return to step 101.

[0057] Different from that described above with respect to Figure 1 the inventors additionally recognize that certain physiological information sensed from a patient over one or more time periods can be used to determine one or more CRT response metrics, and such one or more determined CRT response metrics can be used to provide an alert or notification, or otherwise control the transition between different medical device modes, including, in certain examples, for: (1) controlling the transition from a CRT mode to a non-CRT mode; (2) controlling the transition from a CRT mode to an MSP treatment mode; or (3) enabling or disabling the CRT mode. In certain examples, an alert itself is a type of notification that a determination has been made, which obtains information from multiple sensors or sources and arrives at a determination.

[0058] In an example, the inventors have recognized that, among other things, differences in patient physiological information can be used to distinguish between CRT responders and non-responders, the physiological information including one or more of the following: heart sound information (e.g., first heart sound (S1) information, third heart sound (S3) information, etc.), ITTI information, activity level information, respiratory rate information, RSBI information, or permutations or combinations thereof.

[0059] In certain examples, prior to implanting a second medical device (e.g., an implantable medical device) capable of or configured to provide one or both of CRT and MSP treatment, a first medical device (such as one or more wearable or ambulatory medical devices) can be used to sense physiological information from the patient to evaluate whether the patient is likely to be a responder to one or both of CRT or MSP treatment. The first medical device can sense or collect the patient's physiological information from one or more sensors in the first or one or more other medical devices. Prior to implanting the second medical device, the sensed or collected patient physiological information can be analyzed to determine the recommended type of the second medical device (e.g., a device having a treatment mode coordinated with the determined CRT response metric), and to determine the recommended settings (such as treatment modes or parameters based on the analyzed physiological information).

[0060] As described above with respect to the Saba study, the existing procedure for determining which CRT device to implant is the patient's condition (e.g., diagnosed with heart failure with myocardial dysfunction, etc.), which results in 25% to 40% of CRT non-responders. Even for non-responders, the implanted CRT device has monitoring value because the CRT device will detect the patient's physiological information, determine the patient's status, and in some examples provide one or more other non-CRT functions (e.g., atrial or ventricular backup pacing, defibrillator function, etc.). Although half of the CRT non-responders respond to MSP treatment, it still results in 12% to 30% of patients undergoing an implantation procedure for a CRT device that is unresponsive to CRT or MSP treatment. Additionally, even switching to MSP treatment mode results in additional use of CRT device resources that could otherwise be used to perform or extend the useful life of one or more other device functions. A determination must be made as to whether switching to MSP is worth the resource use (even among non-CRT responders).

[0061] Using a first medical device to determine one or both of a CRT response metric or an MSP response metric before implanting a second medical device can help select or provide one or more alerts or notifications indicating the proposed second medical device, and in some examples, can reduce unnecessary lead placement, simplify the implantation procedure, or even eliminate the implantation procedure for the second medical device entirely.

[0062] Figure 2 An example process 200 for determining one or more patient metrics before final selection or implantation of a second medical device is shown. In some examples, one or more of the determined patient metrics can be used to select or determine a specific device for implantation, a specific mode or treatment to be applied by a specific device, or even eliminate the implantation entirely.

[0063] At step 201, a first medical device, such as a wearable medical device (e.g., a patch-based medical device configured to be worn during an evaluation period, etc.), can be used over a first time period to receive the patient's physiological information from one or more sensors, in some examples, by using a signal receiver circuit. In some examples, one or more of the sensors can include sensors of the first medical device. In other examples, the first medical device can receive information from one or more sensors external to the first medical device. The received physiological information can include one or more of the following: heart sound information (e.g., S1, S3, etc.), ITTI information, activity level information, respiratory rate information, RSBI information, or permutations or combinations thereof.

[0064] At step 202, patient metrics (such as one or more CRT or MSP response metrics) available relative to a second medical device can be determined based on the received physiological information (such as described above). In some examples, an evaluation circuit can be used. One or more determined patient metrics can be compared with one or more thresholds. In some examples, as a combined metric or a combination of physiological information and a threshold, as a separate metric compared to a specific threshold, or a combination or permutation thereof. One or more determined patient metrics can be used to determine whether a particular second medical device should be implanted in a patient, and if so, which mode should be implemented in the second medical device.

[0065] At step 203, the determined patient metrics can be compared with a first threshold (TH1), such as using an evaluation circuit. If the determined patient metrics do not exceed the first threshold, at step 204, the second medical device associated with the determined patient metrics is not recommended (e.g., via an alert, notification, etc.). If the determined patient metrics do exceed the first threshold, the second medical device associated with the determined patient metrics (e.g., a device having or capable of providing a CRT mode, etc.) is recommended (e.g., via an alert, notification, etc.), and the process can continue to step 205 to additionally determine whether a particular mode (e.g., an MSP treatment mode) should be implemented on the second medical device.

[0066] At step 205, the determined patient metrics can be compared with a second threshold (TH2), such as by using an evaluation circuit. If the determined patient metrics do not exceed the second threshold, at step 206, the second medical device associated with the determined patient metrics (e.g., having or capable of providing a CRT mode, etc.) is recommended (e.g., via an alert, notification, etc.). If the determined patient metrics do exceed the second threshold, the second medical device associated with the determined patient metrics (e.g., having or capable of providing a CRT mode, etc.) is recommended, and additionally, a particular mode (e.g., an MSP treatment mode) is activated at step 207.

[0067] In some examples, once determined, one or more recommendations can be provided to one or more other machines or processes, or one or more alerts can be provided to a clinician or user indicating that a recommendation (resulting from processing different data from different sensors or sources) has been determined, including an indication of the final recommendation.

[0068] For example, if the CRT response metric indicates a likely responder, the second medical device can be identified or selected as a device capable of performing CRT or having a CRT mode, and an indication can be made to implant the second medical device with the CRT mode turned on, in some examples, at an initial recommended setting determined using information from the first medical device. If the CRT response metric indicates a likely non-responder (e.g., a CRT response metric below a threshold), and the MSP response metric indicates a likely responder, the second medical device can be identified or selected as a device capable of performing MSP therapy or having an MSP therapy mode, and an indication can be provided to implant the second medical device with the MSP therapy mode turned on, in some examples, at an initial recommendation or recommended setting determined using information from the first medical device.

[0069] In an example, rather than a patch or wearable device as an example of the first medical device, in other examples the first medical device can include a second medical device that is only partially implanted, or is in a pocket (e.g., subcutaneously implanted in the patient's chest, etc.) where the pocket is not closed during a first time period of information collection, such that the location is open for different lead placements, etc. Alternatively, before deciding to use the second medical device to perform CRT or MSP therapy in a patient, the second medical device can be implanted and used during a first time period such that the second medical device can be used as a data collection and analysis device before providing one or more therapies or performing CRT or MSP therapy, etc.

[0070] To determine one or more patient metrics, different physiological information is analyzed during a first time period or one or more other time periods (e.g., longer or shorter than the first time period). For example, heart sound information (e.g., S3 / S1, etc.) and RSBI information are analyzed during a first time period (e.g., 60 days after implantation of the second medical device, etc.). Additionally, ITTI information and RSBI information are analyzed during a second time period (e.g., 150 days after implantation, which includes the first time period, etc.). The above equation (1) can be used to determine whether a patient is likely to respond to an MSP therapy mode using one or both of the ITTI information and the RSBI information. In an example, the inventors have recognized that heart sound information (in some examples, particularly S3 / S1) is particularly well correlated with determining whether a patient is likely to respond to a CRT mode (or a CRT mode or an MSP therapy mode) compared to non-responders (e.g., there are differences in heart sound information between responders and non-responders). The inventors have also recognized that the RSBI information is similarly well correlated. In an example, the CRT response metric can be determined using one or both of heart sound information (such as S3 / S1, etc.) and RSBI information, and in some examples, can also be determined in combination with one or more other parameters. An example is provided below, namely equation (2).

[0071] p(CRT response ) ∝ (α × (S3 / S1)) + (β × RSBI)(2)

[0072] In Equation (2), p(CRT response ) is a patient metric (e.g., a CRT response metric), S3 is a third heart sound parameter (e.g., the amplitude or energy of the third heart sound, etc.), S1 is a first heart sound parameter (e.g., the amplitude or energy of the first heart sound, etc.), RSBI is the ratio of the measured value of the patient's respiratory rate (RR) or frequency to the measured value of the tidal volume (e.g., RR / TV, etc.), and α and β are variables. In other examples, the patient metric can be determined using a combination of this heart sound information or other heart sound information (e.g., other than S3 / S1, etc.), using only one of the heart sound or RSBI information, using information within different time periods (e.g., a 60-day period, a 150-day period, etc.), or as a different function of the combination of one or more such physiological parameters with one or more other physiological parameters.

[0073] For example, a relatively high S3 / S1 may indicate that the patient is likely a responder to CRT or MSP treatment. However, a relatively low S3 / S1 can be combined with other information (such as one or more parameters from Equation (1) above) to determine whether the patient is likely a responder to MSP treatment (rather than CRT). Relatively high and low can be proportional to the individual measurements or can be determined by comparing data from responders and non-responders. In some examples, the individual parameters can include differences, such as indicating the change or variance of daily values over a period of time.

[0074] Figure 3A -C shows an example of heart sound information 300 (e.g., S3 / S1) for a patient within a first time period (e.g., 60 days) after implantation of a CRT device. Figure 3A Shows example heart sound information for an initial responder to CRT (labeled "C"), a subsequent responder to MSP treatment (labeled "M"), and a non-responder to CRT and MSP treatment (labeled "N"). Figure 3B Shows example heart sound information for an initial responder (labeled "C") and others (labeled "O") (e.g., including subsequent responders to MSP treatment, and non-responders, etc.). Figure 3C Shows example heart sound information for a subsequent responder to MSP treatment (labeled "M") and a subsequent non-responder to MSP treatment (labeled "X"). Each shown example also includes an average representation of the corresponding information, as shown by the wider filled line (labeled "A").

[0075] In some examples, as described above, heart sound information may be particularly suitable for differentiating initial responders and non-responders to CRT, or differentiating initial responders to CRT and other patients (e.g., subsequent responders to MSP treatment or non-responders to both CRT and MSP treatment, etc.).

[0076] Figure 4A -C shows example RSBI information 400 for a patient within a first time period (e.g., 60 days) after implanting a CRT device. Figure 4A Shows example RSBI information for an initial responder to CRT (labeled "C"), a subsequent responder to MSP treatment (labeled "M"), and a non-responder to both CRT and MSP treatment (labeled "N"). Figure 4B Shows example RSBI information for an initial responder (labeled "C") and others (labeled "O") (e.g., including subsequent responders to MSP treatment, non-responders, etc.). Figure 4C Shows example RSBI information for a subsequent responder to MSP treatment (labeled "M") and a subsequent non-responder to MSP treatment (labeled "X"). Each shown example also includes an average representation of the corresponding information, as shown by the wider filled line (labeled "A").

[0077] In some examples, as described above, RSBI information may be particularly suitable for differentiating initial responders to CRT from other patients (e.g., subsequent responders to MSP or non-responders to both CRT and MSP treatment, etc.), differentiating subsequent responders to MSP from other patients (e.g., initial responders to CRT or non-responders to both CRT and MSP treatment, etc.), or differentiating subsequent responders to MSP treatment from subsequent non-responders to MSP treatment.

[0078] In other examples, the sensed or received physiological information of the patient, or a combination of the sensed or received physiological information of the patient used frequently, can be used to determine one or more other patient metrics. The inventors have considered various different physiological information for determining patient response metrics, which includes heart sound information (especially S1 and S3 information), ITTI information, respiratory rate information, RSBI information, nocturnal heart rate information, activity information, and the multi-sensor HeartLogic index.

[0079] The HeartLogic index is a composite heart failure risk indicator determined using a combination of different physiological information, which includes heart sound information (including S1 and S3), respiratory rate and volume information, ITTI information, heart rate information (e.g., especially the nocturnal heart rate of the patient determined between midnight and 6 am), and the patient's daily activity information (e.g., the number of daily hours above an activity threshold).

[0080] From a randomly selected 60% subset of the development patients (183 CRT responders and 40 CRT non-responders), the following statistical measures were calculated for each parameter based on the first 150-day period after implantation of a cardiac rhythm therapy device: overall mean (μ150), mean for the first 30 days (μF30) or last 30 days (μL30) of the period, and standard deviation (σ150). To evaluate the effect of each measure on response or non-response, odds ratios were calculated and tested for significance. Based on the initial univariate analysis, measures with a p-value < 0.15 were subsequently included in a multivariate logistic regression model and backward elimination was performed to achieve p < 0.05 for the remaining variables.

[0081] In the univariate model, an increase in S3, the S3 / S1 ratio, RSBI, respiratory rate, and 150-day variability (σ150) of the HeartLogic index was significantly associated with a decrease in the odds of a positive response to CRT. Similarly, an increase in the mean of RSBI, respiratory rate, and HeartLogic index was significantly associated with a decrease in the odds of a positive response to CRT. Multiple device-based physiological parameters were significantly different between CRT responders and non-responders. Respiratory rate variability and daily activity remained significant in the multivariate analysis.

[0082] Accordingly, the present inventors unexpectedly recognized that respiratory variability information (e.g., respiratory rate variability (e.g., 1 BPM change), etc.) and daily activity information (e.g., the amount of time the patient is active above a threshold, the number of hours the patient is active above a threshold, etc.) are strong indicators of CRT response or non-response. In some examples, patient metrics can be determined using one or more of the respiratory variability information or daily activity information to identify patients who may respond to one or both of CRT or MSP therapy, identify patients who may benefit from switching from CRT to MSP therapy, and in some examples distinguish MSP therapy responders and non-responders once MSP therapy is provided. The evaluation circuit can be configured to provide one or more alerts, make one or more recommendations, or provide one or more control signals to control the generation or delivery of one or more stimulation signals, or the implementation of one or more different stimulation patterns.

[0083] Figure 5The determined odds ratio 500 for physiological information associated with CRT response is shown, where each 1 unit or standard deviation change has a 95% confidence interval. An odds ratio of 1 has no effect on the outcome. In contrast, the further the odds ratio is from 1, the greater the indication of an effect on the outcome, where an odds ratio greater than 1 is associated with a higher odds of the outcome and an odds ratio less than 1 is associated with a lower odds of the outcome. Different odds are marked on a line centered on a diamond, where patterned odds indicate significant values compared to unpatterned odds. The multivariable model starts with measures having a p-value < 15 from the univariate analysis and is simplified using backward elimination to identify the most significant indicators. Although respiratory variability and daily activity are most significant, other physiological information still has important value, including heart sound information (such as S3, S3 / S1, etc.), RSBI information, and in some examples, the HeartLogic index.

[0084] In an example, a patient metric can be determined using patient physiological information such as one or more of respiratory variability information or daily activity information, or in some examples, heart sound information, RSBI information, or a combination or permutation thereof. In some examples, the determined patient metric can indicate a need for CRT, MSP therapy, or a combination thereof, or indicate that a patient may be a responder or non-responder to CRT or MSP therapy. In other examples, the determined patient metric can be used to control transitions between treatment modes, such as transitioning to one or more of a CRT mode and an MSP therapy mode, transitioning between them, or transitioning out of them.

[0085] The following characteristics have been found to be associated with CRT response and are identified as the most significant indicators, as described above: HeartLogic index (e.g., HeartLogic index crude mode, number of days the HeartLogic index exceeds the population mean); ITTI (e.g., ITTI maximum real FFT (Fast Fourier Transform)); respiratory rate (e.g., RR standard deviation); activity (e.g., change in activity from the first 30 days to the last 30 days of the evaluation period); and so on.

[0086] The following features were found to be associated with subsequent responders to MSP treatment and were identified as the most significant indicators, as described above: ITTI (e.g., ITTI crude mode, number of days ITTI above the population mean); RSBI (e.g., RSBI power spectral density (PSD) peak width, number of days RSBI above the population mean), etc. In other examples, other significant features may include: RR (e.g., RR FFT image maximum, RR average, RR average over the last 30 days (last 30 days of the evaluation period)), S3 (e.g., S3 late average), RSBI (e.g., RSBI average over 30 days before switching from CRT to MSP treatment, RSBI average over the last 30 days), ITTI (e.g., ITTI standard deviation), HR (e.g., HR increment), etc.

[0087] Predicting Respiratory and Intrathoracic Impedance-Driven CRT and Subsequent MSP Response. HeartLogic and activity levels are also useful in predicting the initial CRT response. Determination of the MSP response metric was found to be more influential when using RSBI compared to RR. Thus, tidal volume (TV) can be a driver for determining the MSP response metric with respect to MSP response.

[0088] Figure 6 An implantable medical device (IMD) 600 electrically coupled to a heart 605 is shown, such as via one or more leads that are coupled to the IMD 600 through one or more lead ports (such as a first, second, or third lead port 641, 642, 643 in a head 602 of the IMD 600). In an example, the IMD 600 may include an antenna (such as in the head 602) configured to be able to communicate with an external system and one or more electronic circuits (e.g., an evaluation circuit, etc.) in a hermetically sealed can (CAN) 601.

[0089] The IMD 600 can include an implantable medical device (IMD), such as an implantable cardiac monitor (ICM), a pacemaker, a defibrillator, a cardiac resynchronizer, or other subcutaneous IMD or cardiac rhythm management (CRM) device, which is configured to be implanted in a subject's chest and has one or more leads to position one or more electrodes or other sensors at various locations in or near the heart 605 (such as one or more in the atrium or ventricle). Separate from or in addition to the one or more electrodes or other sensors of the leads, the IMD 600 can include one or more electrodes or other sensors (such as a pressure sensor, an accelerometer, a gyroscope, a microphone, etc.) powered by a power source in the IMD 600. One or more electrodes or other sensors of the leads, the IMD 600, or a combination thereof can be configured to detect physiological information from the patient or to provide one or more therapies or stimulations to the patient.

[0090] The IMD 600 can include one or more electronic circuits, which are configured to sense one or more physiological signals (such as an electrogram or a signal representing the mechanical function of the heart 605). In some examples, the CAN 601 can be used as an electrode for sensing or pulse delivery. For example, electrodes from one or more leads can be used with the CAN 601, such as for unipolar sensing of an electrogram or for delivering one or more pacing pulses. Defibrillation electrodes (such as a first defibrillation coil electrode 628, a second defibrillation coil electrode 629, etc.) can be used with the CAN 601 to deliver one or more cardioversion / defibrillation pulses.

[0091] In an example, the IMD 600 can sense the impedance, such as between electrodes located on one or more leads or the CAN 601. The IMD 600 can be configured to inject a current between a pair of electrodes, sense the resultant voltage between the same or different pairs of electrodes, and determine the impedance, such as using Ohm's law. The impedance can be sensed in a bipolar configuration (in which the same pair of electrodes can be used for current injection and voltage sensing), a tripolar configuration (in which the pair of electrodes for current injection and the pair of electrodes for voltage sensing can share a common electrode), or a quadripolar configuration (in which the electrodes for current injection can be different from the electrodes for voltage sensing), etc. In an example, the IMD 600 can be configured to inject a current between an electrode on one or more of the first, second, third, or fourth leads 620, 625, 630, 635 and the CAN 601 and sense the resultant voltage between the same or different electrodes and the CAN 601.

[0092] Figure 6Exemplary lead configurations therein include first, second, and third leads 620, 625, 630 in conventional lead placement in the coronary vein 616 (e.g., coronary sinus) correspondingly above the right atrium (RA) 606, right ventricle (RV) 607, left atrium (LA) 608, and left ventricle (LV) 609, and a fourth lead 635 positioned near the His bundle 611 in the RV 607 between the AV node 610, left bundle branch 612, right bundle branch 613, and Purkinje fibers 614, 615. Each lead may be configured to position one or more electrodes or other sensors at various locations in or near the heart 605 to detect physiological information or provide one or more therapies or stimulations.

[0093] The first lead 620 positioned in the RA 606 includes a first tip electrode 621 at or near the distal end of the first lead 620 and a first ring electrode 622 near the first tip electrode 621. The second lead 625 (dashed line) positioned in the RV 607 includes a second tip electrode 626 at or near the distal end of the second lead 625 and a second ring electrode 627 near the second tip electrode 626. The third lead 630 in the coronary vein 616 above the LV 609 includes a third tip electrode 631 at or near the distal end of the third lead 630, a third ring electrode 632 near the third tip electrode 631, and two additional electrodes 633, 634. The fourth lead 635 positioned near the His bundle 611 in the RV 607 includes a fourth tip electrode 636 at or near the distal end of the fourth lead 635 and a fourth ring electrode 637 near the fourth tip electrode 636. The tip and ring electrodes may include pacing / sensing electrodes configured to sense electrical activity or provide pacing stimulation.

[0094] In addition to the tip and ring electrodes, one or more leads may also include one or more defibrillation coil electrodes configured to sense electrical activity or provide cardioversion or defibrillation shock energy. For example, the second lead 625 includes a first defibrillation coil electrode 628 near the distal end of the second lead 625 in the RV 607 and a second defibrillation coil electrode 629 at a distance from the distal end of the second lead 625, such as the electrode placed in or near the superior vena cava (SVC) 617.

[0095] Different CRM devices include different numbers of leads and lead placements. For example, some CRM devices are single-lead devices having one lead (e.g., only RV, only RA, etc.). Other CRM devices are multi-lead devices having two or more leads (e.g., RA and RV; RV and LV; RA, RV, and LV, etc.). CRM devices suitable for His bundle pacing typically use a lead port designated for an LV or RV lead to deliver stimulation to the His bundle 611.

[0096] Figure 7 An example system 700 (e.g., a medical device system) is shown. In an example, one or more aspects of the example system 700 can be components of a medical device (such as an implantable medical device (IMD)), an insertable cardiac monitor, a mobile medical device (AMD), etc., or communicatively coupled to a medical device (such as an implantable medical device (IMD)), an insertable cardiac monitor, a mobile medical device (AMD), etc. The system 700 can be configured to monitor, detect, or treat various physiological conditions of the body, such as cardiac conditions associated with a reduced ability of the heart to pump blood to the body, including heart failure, arrhythmia, cardiac dyssynchrony, etc., or one or more other physiological conditions, and in certain examples, can be configured to provide electrical stimulation or one or more other therapies or treatments to a patient.

[0097] The system 700 can include a single medical device or multiple medical devices implanted in a patient or otherwise positioned on or around the patient to monitor patient physiological information of the patient using one or more sensors (such as sensor 701). In an example, the sensor 701 can include one or more of the following: a respiratory sensor configured to receive respiratory information (e.g., respiratory rate, respiratory volume (tidal volume), etc.); an acceleration sensor (e.g., an accelerometer, a microphone, etc.) configured to receive cardiac acceleration information (e.g., cardiac vibration information, pressure waveform information, heart sound information, endocardial acceleration information, acceleration information, activity information, body position information, etc.); an impedance sensor (e.g., an intrathoracic impedance sensor, a transthoracic impedance sensor, a thoracic impedance sensor, etc.) configured to receive impedance information; a cardiac sensor configured to receive cardiac electrical information; an activity sensor configured to receive information about body movement (e.g., activity, steps, etc.); a body position sensor configured to receive body position or location information; a pressure sensor configured to receive pressure information; a plethysmography sensor (e.g., a photoplethysmography sensor, etc.); a chemical sensor (e.g., an electrolyte sensor, a pH sensor, an anion gap sensor, etc.); a temperature sensor; a skin elasticity sensor; or one or more other sensors configured to receive physiological information of the patient.

[0098] Example system 700 may include a signal receiver circuit 702 and an evaluation circuit 703. The signal receiver circuit 702 may be configured to receive physiological information of a patient (or group of patients) from a sensor 701. The evaluation circuit 703 may be configured to receive information from the signal receiver circuit 702 and use the received physiological information to determine one or more parameters (e.g., physiological parameters, stratification factors, etc.) or an existing or changing patient condition (e.g., an indication of patient dehydration, respiratory condition, cardiac condition (e.g., heart failure, arrhythmia), sleep apnea disorder, etc.), such as described herein. Among other things, the physiological information may include cardiac electrical information, impedance information, respiratory information, heart sound information, activity information, position information, temperature information, or one or more other types of physiological information.

[0099] In some examples, the evaluation circuit 703 may aggregate information from multiple sensors or devices, detect various events using the information from each sensor or device individually or in combination, update a detection status for one or more patients based on the information, and transmit a message or alert to one or more remote devices that a detection has been made of one or more patients or that information has been stored or transmitted, such that one or more additional processes or systems may use the stored or transmitted detection or information for one or more other checks or processes.

[0100] In some examples, such as to detect an improvement or deterioration in a patient's condition, some initial evaluation is typically required to establish a baseline level or condition based on one or more sensors or physiological information. Subsequent detection of a deviation from the baseline level or condition can be used to determine an improvement or deterioration in the patient's condition. However, in other examples, the amount of deviation or change in physiological information over different time periods (e.g., relative or absolute change) can be used to determine the risk of an adverse medical event, or to predict or stratify the risk that a patient will experience an adverse medical event (e.g., a heart failure event) for a period of time following a detected change, either in combination with or separate from any baseline level or condition.

[0101] Changes in different physiological information can be aggregated and weighted based on one or more patient-specific stratifiers and, in some examples, compared to one or more thresholds, e.g., to be clinically sensitive and specific for a particular condition (such as heart failure) across a target population and for one or more specific time periods, such as daily values, short-term averages (e.g., daily values aggregated over several days), long-term averages (e.g., daily values aggregated over multiple short time periods or more days (sometimes with a different (e.g., non-overlapping) number of days compared to the short-term average)), etc.

[0102] The evaluation circuit 703 can be configured to provide an output to a user, such as to a display or one or more other user interfaces, the output including a score, a trend, a warning, or other indication. In other examples, the evaluation circuit 703 can be configured to provide an output to another circuit, machine, or process, such as the therapy circuit 704 (e.g., a cardiac resynchronization therapy (CRT) circuit, a chemotherapy circuit, a stimulation circuit, etc.) to control, adjust, or stop the therapy of a medical device, a drug delivery system, etc., or to otherwise change one or more processes or functions of one or more other aspects of the medical device system, such as one or more CRT parameters, drug delivery, dose determination or recommendation, etc. In an example, the therapy circuit 704 can include one or more of a stimulation control circuit, a cardiac stimulation circuit, a nerve stimulation circuit, a dose determination or control circuit, etc. In other examples, the therapy circuit 704 can be controlled by the evaluation circuit 703 or one or more other circuits, etc.

[0103] There are technical problems in medical devices and medical device systems, i.e., in the low-power monitoring mode, a portable medical device (e.g., including an IMD) powered by one or more rechargeable or non-rechargeable batteries must make certain trade-offs between battery lives, or in the case of an implantable medical device with non-rechargeable batteries, between device replacement periods that typically include surgical procedures, and the sampling resolution, sampling period of the processing, storage, and transmission of the sensed physiological information, or the selection of features or modes within the medical device or within the medical device. A medical device can include a higher-power mode and a lower-power mode. Physiological information (such as indicating a potential adverse physiological event) can be used to switch from the low-power mode to the high-power mode. In some examples, the low-power mode can include a low-resource mode, which is characterized by requiring less power, processing time, memory, or communication time or bandwidth (e.g., transmitting less data, etc.) than the corresponding high-power mode. The high-power mode can include a relatively high-resource mode, which is characterized by requiring more power, processing time, memory, or communication time or bandwidth than the corresponding low-power mode. However, when valuable information has been lost during the time of physiological information detected in the low-power mode indicating a possible event, it cannot be recorded in the high-power mode.

[0104] Vice versa, because an incorrect or inaccurate determination that triggers the high-power mode unnecessarily and inappropriately limits the service life of some portable medical devices. For various reasons, it is beneficial to accurately detect and determine physiological events and avoid unnecessary transitions from the low-power mode to the high-power mode to improve the utilization rate of medical device resources.

[0105] Figure 8Illustrates an exemplary patient management system 800 and a portion of an environment in which the patient management system 800 may operate. The patient management system 800 may perform a series of activities, including remote patient monitoring and disease condition diagnosis. Such activities may be performed proximal to the patient 801, such as in the patient's home or office, by a central server, such as in a hospital, clinic, or doctor's office, or by a remote workstation, such as a secure wireless mobile computing device.

[0106] The patient management system 800 may include one or more medical devices, an external system 805, and a communication link 811 that provides for communication between one or more mobile medical devices and the external system 805. The one or more medical devices may include a mobile medical device (AMD) (such as an implantable medical device (IMD) 802), a wearable medical device 803, or one or more other implantable, leadless, subcutaneous, external, wearable, or medical devices that are configured to monitor, sense, or detect information from the patient 801, determine physiological information about the patient 801, or provide one or more therapies to treat various conditions of the patient 801, such as one or more cardiac or non-cardiac conditions (e.g., dehydration, sleep apnea, etc.).

[0107] In an example, the implantable medical device 802 may include one or more cardiac rhythm management devices implanted in the patient's chest, having a lead system that includes one or more transvenous, subcutaneous, or non-invasive leads or catheters to position one or more electrodes or other sensors (such as a heart sound sensor) within, on, or around the heart, or in one or more other locations in the patient 801's chest, abdomen, or neck. In another example, the implantable medical device 802 may include, for example, a monitor subcutaneously implanted in the patient 801's chest, the implantable medical device 802 including a housing containing circuitry and, in certain examples, including one or more sensors, such as a temperature sensor, etc.

[0108] Cardiac rhythm management devices, such as implantable cardiac monitors, pacemakers, defibrillators, or cardiac resynchronizers, include implantable or subcutaneous devices having an airtight sealed housing configured to be implanted in a patient's chest. The cardiac rhythm management device may include one or more leads to position one or more electrodes or other sensors at various locations in or near the heart, such as in one or more of the atria or ventricles of the heart. Thus, the cardiac rhythm management device may include aspects that are subcutaneous, although near the distal skin of the patient, and aspects that are near one or more organs of the patient, such as leads or electrodes. Separate from or in addition to the one or more electrodes or other sensors of the lead, the cardiac rhythm management device may include one or more electrodes or other sensors (e.g., pressure sensors, accelerometers, gyroscopes, microphones, etc.) powered by a power source in the cardiac rhythm management device. The one or more electrodes or other sensors of the lead, the cardiac rhythm management device, or a combination thereof may be configured to detect physiological information from the patient or provide one or more therapies or stimuli to the patient.

[0109] The implantable device may additionally or alternatively include a leadless cardiac pacemaker (LCP), which is a small (e.g., smaller than traditional implantable cardiac rhythm management devices, having a volume of approximately 1 cc in some examples, etc.) self - contained device that includes one or more sensors, circuitry, or electrodes configured to monitor physiological information from the heart (e.g., heart rate, etc.), detect physiological conditions associated with the heart (e.g., tachycardia), or provide one or more therapies or stimuli to the heart without the complications associated with traditional leads or implantable cardiac rhythm management devices (e.g., the required incisions and pockets, complications associated with lead placement, breakage, or displacement, etc.). In some examples, the leadless cardiac pacemaker may have more limited power and processing capabilities than traditional cardiac rhythm management devices; however, multiple leadless cardiac pacemakers may be implanted in or around the heart to detect physiological information from one or more chambers of the heart or provide one or more therapies or stimuli to one or more chambers of the heart. The multiple leadless cardiac pacemakers may communicate with each other, or with one or more other implantable devices or external devices.

[0110] An implantable medical device 802 may include an evaluation circuit configured to detect or determine specific physiological information of a patient 801, or determine one or more conditions, or provide information or alerts to a user (such as the patient 801 (e.g., the patient), a clinician, or one or more other caregivers or processes), such as described herein. The implantable medical device 802 may alternatively or additionally be configured as a treatment device configured to treat one or more medical conditions of the patient 801. The treatment may be delivered to the patient 801 via a lead system and associated electrodes or using one or more other delivery mechanisms. The treatment may include delivering one or more drugs to the patient 801, such as using the implantable medical device 802 or one or more other mobile medical devices. In some examples, the treatment may include CRT for correcting asynchrony and improving cardiac function in patients with heart failure. In other examples, the implantable medical device 802 may include a drug delivery system, such as a drug infusion pump for delivering a drug to the patient for managing arrhythmias or complications caused by arrhythmias, hypertension, hypotension, or one or more other physiological conditions. In other examples, the implantable medical device 802 may include one or more electrodes configured to stimulate the patient's nervous system or provide stimulation to the muscles of the patient's airway, etc.

[0111] A wearable medical device 803 may include one or more wearable or external medical sensors or devices (such as an automated external defibrillator (AED), a Holter monitor, a patch-based device, a smartwatch, a smart accessory, a wrist-worn or finger-worn medical device, such as a finger-based photoplethysmography sensor, etc.).

[0112] The external system 805 may include a dedicated hardware / software system, such as a programmer, a remote server-based patient management system, or alternatively a system defined primarily by software running on a standard personal computer. The external system 805 may manage the patient 801 through the implantable medical device 802 or one or more other mobile medical devices connected to the external system 805 via a communication link 811. In other examples, the implantable medical device 802 may be connected to a wearable medical device 803, or the wearable medical device 803 may be connected to the external system 805 via the communication link 811. For example, this may include programming the implantable medical device 802 to perform one or more of collecting physiological data, performing at least one self-diagnostic test (such as a self-diagnostic test for the device operating state), analyzing physiological data, or optionally delivering or adjusting therapy to the patient 801. Additionally, the external system 805 may send information to or receive information from the implantable medical device 802 or the wearable medical device 803 via the communication link 811. Examples of information may include real-time or stored physiological data from the patient 801, diagnostic data (such as detection of the patient's hydration status, hospitalization, response to therapy delivered to the patient 801), or the device operating state of the implantable medical device 802 or the wearable medical device 803 (e.g., battery state, lead impedance, etc.). The communication link 811 may be an inductive telemetry link, a capacitive telemetry link, or a radio-frequency (RF) telemetry link, or a wireless telemetry based on, for example, the "strong" Bluetooth or IEEE 602.11 Wi-Fi interface standard. Other configurations and combinations of patient data source interfaces are possible.

[0113] The external system 805 may include an external device 806 near one or more mobile medical devices and a remote device 808 at a location relatively far from the one or more mobile medical devices, which communicates with the external device 806 via a communication network 807. Examples of the external device 806 may include a medical device programmer. Among other possible functions, the remote device 808 may be configured to evaluate the collected patient or patient information and provide alert notifications. In an example, the remote device 808 may include a centralized server that serves as a central hub for storing and analyzing data collected from multiple different sources. The combination of information from multiple sources may be used to make determinations and update individual patient status, or to adjust one or more alerts or determinations for one or more other patients. The server may be configured as a single, multi-, or distributed computing and processing system. The remote device 808 may receive data from multiple patients. The data may be collected by one or more mobile medical devices other than other data acquisition sensors or devices associated with the patient 801. The server may include a memory device to store the data in a patient database. The server may include an alert analyzer circuit to evaluate the collected data to determine whether specific alert conditions are met. The satisfaction of the alert conditions may trigger the generation of an alert notification, such as an alert notification to be provided by one or more human-perceivable user interfaces. In some examples, the alert conditions may alternatively or additionally be evaluated by one or more mobile medical devices (such as implantable medical devices). For example, the alert notification may include a web page update, a phone call or pager, an email, an SMS, a text or "instant" message, and a message to the patient and a direct notification to emergency services and clinicians simultaneously. Other alert notifications are possible. The server may include an alert prioritizer circuit configured to prioritize the alert notifications. For example, alerts for detected medical events may be prioritized using a similarity metric between the physiological data associated with the detected medical event and the physiological data associated with historical alerts.

[0114] Additionally, the remote device 808 may include one or more locally configured clients or remote clients securely connected to the server via the communication network 807. Examples of clients may include personal desktop computers, laptops, mobile devices, or other computing devices. System users (such as clinicians or other qualified medical professionals) may use the clients to securely access the stored patient data compiled in the database in the server, and select patients and alerts and prioritize them for healthcare delivery. In addition to generating alert notifications, the remote device 808 (including the server and interconnected clients) may also execute a follow-up program by sending a follow-up request to one or more mobile medical devices, or by sending a message or other communication to the patient 801 (such as the patient), the clinician, or an authorized third party as a compliance notification.

[0115] The communication network 807 can provide wired or wireless interconnectivity. In an example, the communication network 807 can be based on the Transmission Control Protocol / Internet Protocol (TCP / IP) network communication specification, although other types or combinations of networking implementations are possible. Similarly, other network topologies and arrangements are possible.

[0116] One or more of the external device 806 or the remote device 808 can output the detected medical event to a system user (such as a patient or a clinician) or to a process (such as an instance of a computer program executable in a microprocessor). In an example, the process can include the automatic generation of a recommendation for anti-arrhythmia treatment or a recommendation for further diagnostic tests or treatment. In an example, the external device 806 or the remote device 808 can include a corresponding display unit for displaying physiological signals or functional signals, or issuing a warning, alarm, emergency call, or other form of warning of the detected arrhythmia signal. In some examples, the external system 805 can include an external data processor configured to analyze physiological signals or functional signals received by one or more mobile medical devices and confirm or reject the detection of arrhythmia. Computationally intensive algorithms (such as machine learning algorithms) can be implemented in the external data processor for retrospectively processing data to detect arrhythmia.

[0117] One or more parts of the mobile medical devices or the external system 805 can be implemented using hardware, software, firmware, or a combination thereof. One or more parts of the mobile medical devices or the external system 805 can be implemented using a dedicated circuit that can be constructed or configured to perform one or more functions, or can be implemented using a general-purpose circuit that can be programmed or otherwise configured to perform one or more functions. Such general-purpose circuits can include a microprocessor or a part thereof, a microcontroller or a part thereof, or a programmable logic circuit, a memory circuit, a network interface, and various components for interconnecting these components. For example, among other things, a "comparator" can include an electronic circuit comparator that can be configured to perform a specific function of comparing two signals, or the comparator can be implemented as part of a general-purpose circuit that can be driven by code instructing the part of the general-purpose circuit to perform a comparison between two signals. A "sensor" can include an electronic circuit configured to receive information and provide an electronic output representing such received information.

[0118] The treatment device 810 may be configured to send information to or receive information from one or more mobile medical devices or an external system 805 using a communication link 811. In an example, one or more mobile medical devices, an external device 806, or a remote device 808 may be configured to control one or more parameters of the treatment device 810. The external system 805 may allow programming of one or more mobile medical devices and may receive information about one or more signals collected by one or more mobile medical devices, such as information that may be received via the communication link 811. The external system 805 may include a local external implantable medical device programmer. The external system 805 may include a remote patient management system, which may monitor a patient's status or adjust one or more treatments, such as from a remote location.

[0119] The mobile medical device may also include or be configured to receive mechanical acceleration information from one or more accelerometer sensors to determine and monitor patient acceleration information, such as cardiac vibration information associated with the heart or blood flow or movement in the patient's vasculature (e.g., heart sounds, heart wall movement, etc.), patient body activity or position information (e.g., patient posture, activity, etc.), respiratory information (e.g., respiratory rate, phase, breath sounds, etc.), and the like.

[0120] Heart sounds are repetitive mechanical signals associated with the acceleration of cardiac vibrations or blood flow through the heart or other cardiac movements having each cardiac cycle or interval, and may be separated and classified according to activities associated with such vibrations, accelerations, movements, pressure waves, or blood flow. Heart sounds include four main features: the first heart sound to the fourth heart sound (correspondingly S1 to S4). The first heart sound (S1) is a vibratory sound emitted by the heart during the closure of the atrioventricular (AV) valves, the mitral and tricuspid valves, and the opening of the aortic valve at the beginning of systole or ventricular contraction. The second heart sound (S2) is a vibratory sound emitted by the heart during the closure of the aortic and pulmonary valves at the beginning of diastole or ventricular relaxation. The third and fourth heart sounds (S3, S4) are related to the filling pressure of the left ventricle during diastole. A sudden stop in early diastolic filling may result in the third heart sound (S3). Vibrations caused by atrial ejection may result in the fourth heart sound (S4). Valve closures and blood movement and pressure changes in the heart may cause acceleration, vibration, or movement of the heart wall, which can be detected using an accelerometer or a microphone, thereby providing an output referred to herein as cardiac acceleration information.

[0121] In an example, the heart sound parameter may include the ensemble average of a specific heart sound on the heart sound waveform, such as disclosed in U.S. Patent No. 7,115,096 to Siejko et al., entitled "THIRD HEART SOUND ACTIVITY INDEX FOR HEART FAILURE MONITORING," and commonly assigned, or in U.S. Patent No. 7,853,327 to Patangay et al., entitled "HEART SOUND TRACKING SYSTEM AND METHOD," and commonly assigned, each of these patents being incorporated herein by reference in its entirety, including their disclosures of ensemble averaging of acoustic signals and determining specific heart sounds of the heart sound waveform.

[0122] In some examples, event storage may be triggered, such as the received physiological information, or in response to one or more detected events or determined parameters reaching or exceeding a threshold (e.g., a static threshold, a dynamic threshold, or one or more other thresholds based on patient or population information, etc.). Information sensed or recorded in a high power consumption mode may be transferred from a short-term storage device (such as in a loop recorder) to long-term or non-volatile memory, or in some examples, prepared for communication to an external device separate from the medical device. In an example, cardiac electrical or cardiac mechanical information that causes a detected atrial fibrillation event may be stored, and in some examples, cardiac electrical or cardiac mechanical information including the detected atrial fibrillation event, such as to increase the specificity of detection. In an example, multiple loop recorder windows (e.g., 2-minute windows) may be stored sequentially. In a system without early detection, to record this information, a loop recorder with a longer time period would be required, which would require a significant additional cost (e.g., power, processing resources, component cost, storage capacity, etc.). Storing multiple windows using such early detection prior to a single event can provide a complete event assessment while saving power and cost compared to a longer loop recorder window. Additionally, early detection may trigger additional parameter calculations or storage at different resolutions or sampling frequencies without overly consuming limited system resources.

[0123] In some examples, one or more alerts may be provided, such as to a patient, a doctor, or one or more other caregivers (e.g., using a patient smartwatch, a cellular or smart phone, a computer, etc.), such as in response to a transition to a high power consumption mode, in response to a detected event or condition, or after updating information or transferring information from a first device to a remote device. In other examples, the medical device itself may provide an auditory or tactile alert to alert the patient of a detected condition. For example, an alert may be issued to the patient in response to a detected condition such that they can take corrective actions, such as sitting down, etc.

[0124] In some examples, treatment can be provided in response to a detected condition. For example, pacing therapy can be provided, enabled, or adjusted, such as to interrupt or reduce the impact of a detected atrial fibrillation event. In other examples, in response to a detected condition, the delivery of one or more drugs (e.g., vasoconstrictors, pressor drugs, etc.) can be triggered, provided, or adjusted (such as using a drug pump), either alone or in combination with pacing therapy (such as the pacing therapy described above), such as to increase arterial pressure, maintain cardiac output, and interrupt or reduce the impact of a detected atrial fibrillation event.

[0125] Figure 9 A block diagram of an example machine 900 is shown on which any one or more of the techniques (e.g., methods) discussed herein can be performed. Portions of the description may apply to the computing framework of one or more of the medical devices (such as wearable medical devices, external programmers, etc.) described herein. Additionally, as described herein with respect to medical device components, systems, or machines, such may require regulatory compliance that may not be achievable by a general-purpose computer, component, or machine.

[0126] As described herein, an example may include logic or multiple components or mechanisms in or operable by machine 900. A circuitry (e.g., a processing circuitry, an evaluation circuitry, etc.) is a collection of circuits implemented in a tangible entity of machine 900 that includes hardware (e.g., simple circuits, gates, logic, etc.). Members of the circuitry may be flexible over time. The circuitry includes members that can perform specified operations individually or in combination when operated. In an example, the hardware of the circuitry can be immutably designed to perform a particular operation (e.g., hardwired). In an example, the hardware of the circuitry can include physically coupled components (e.g., execution units, transistors, simple circuits, etc.) that include a computer-readable medium encoded with instructions for physically modifying (e.g., magnetically, electrically, movable placement of immutably aggregated particles, etc.) to encode instructions for a particular operation. When physically coupling the components, the underlying electrical properties of the hardware composition change, such as from an insulator to a conductor, or vice versa. The instructions enable the embedded hardware (e.g., an execution unit or a loading mechanism) to create members of the circuitry in the hardware via the variable connections to perform portions of a particular operation when operated. Thus, in an example, the computer-readable medium element is part of the circuitry or communicatively coupled to other components of the circuitry when the device is operated. In an example, any of the physical components can be used in more than one member of more than one circuitry. For example, in operation, an execution unit can be used in a first circuit of a first circuitry at one point in time and reused by a second circuit in the first circuitry or by a third circuit in a second circuitry at a different time. The following are additional examples with respect to these components of machine 900.

[0127] In an alternative embodiment, machine 900 may operate as a stand-alone device or may be connected (e.g., networked) to other machines. In a networked deployment, machine 900 may operate in a server-client network environment as a server machine, a client machine, or both. In an example, machine 900 may act as a peer machine in a peer-to-peer (P2P) (or other distributed) network environment. Machine 900 may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile phone, a network appliance, a network router, a switch or bridge, or any machine capable of executing instructions (sequential or otherwise) specifying actions to be taken by that machine. Further, while only a single machine is shown, the term "machine" shall also be taken to include any collection of such machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methods discussed herein, such as cloud computing, software as a service (SaaS), other computer cluster configurations.

[0128] Machine (e.g., computer system) 900 may include a hardware processor 902 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 904, a static memory 906 (e.g., a memory or storage device for firmware, microcode, basic input / output (BIOS), unified extensible firmware interface (UEFI), etc.), and a mass storage device 908 (e.g., a hard disk drive, a tape drive, a flash storage device, or other block device), some or all of which may communicate with each other via an interconnection link 930 (e.g., a bus). Machine 900 may also include a display unit 910, an input device 912 (e.g., a keyboard), and a user interface (UI) navigation device 914 (e.g., a mouse). In an example, the display unit 910, the input device 912, and the UI navigation device 914 may be a touch screen display. Machine 900 may additionally include a signal generation device 918 (e.g., a speaker), a network interface device 920; and one or more sensors 916, such as a global positioning system (GPS) sensor, a compass, an accelerometer, or one or more other sensors. Machine 900 may include an output controller 928, such as a serial connection (e.g., a universal serial bus (USB)), a parallel connection, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection, to communicate or control one or more peripheral devices (e.g., a printer, a card reader, etc.).

[0129] The registers of the hardware processor 902, main memory 904, static memory 906, or mass storage device 908 may be or include a machine-readable medium 922 on which one or more sets of data structures or instructions 924 (e.g., software) are stored, which data structures or instructions embody or are utilized by any one or more of the techniques or functions described herein. The instructions 924 may also reside, completely or at least partially, within any one of the registers of the hardware processor 902, main memory 904, static memory 906, or mass storage device 908 during execution thereof by the machine 900. In an example, one or any combination of the hardware processor 902, main memory 904, static memory 906, or mass storage device 908 may constitute the machine-readable medium 922. Although the machine-readable medium 922 is shown as a single medium, the term "machine-readable medium" may include a single medium or multiple media (e.g., a centralized database or a distributed database, and / or associated caches and servers) configured to store one or more instructions 924.

[0130] The term "machine-readable medium" may include any medium that can store, encode, or carry instructions for execution by the machine 900 and that cause the machine 900 to perform any one or more of the techniques in this disclosure, or that can store, encode, or carry data structures used by or associated with such instructions. Non-limiting examples of machine-readable media may include solid-state memory, optical media, magnetic media, and signals (e.g., radio frequency signals, other photon-based signals, sound signals, etc.). In an example, a non-transitory machine-readable medium includes a machine-readable medium having a plurality of particles that have an invariant (e.g., stationary) mass and are thus a composition of matter. Thus, a non-transitory machine-readable medium is a machine-readable medium that does not include transitory propagated signals. Specific examples of non-transitory machine-readable media may include non-volatile memory such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)), and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks.

[0131] Instruction 924 can also be transmitted or received via a communication network 926 using a transmission medium via a network interface device 920 that utilizes any one of a variety of transmission protocols (e.g., Frame Relay, Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Hypertext Transfer Protocol (HTTP), etc.). Example communication networks can include local area networks (LANs), wide area networks (WANs), packet data networks (e.g., the Internet), mobile telephone networks (e.g., cellular networks), plain old telephone (POTS) networks, and wireless data networks (e.g., the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard family known as the IEEE 802.11 standard family, the IEEE 802.16 standard family known as ), the IEEE 802.15.4 standard family, peer-to-peer (P2P) networks, etc. In an example, network interface device 920 can include one or more physical jacks (e.g., Ethernet jacks, coaxial jacks, or phone jacks) or one or more antennas to connect to communication network 926. In an example, network interface device 920 can include multiple antennas to perform wireless communication using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) techniques. The term "transmission medium" should be considered to include any non-tangible medium that is capable of storing, encoding, or carrying instructions for execution by machine 900, and includes digital or analog communication signals or other non-tangible media to facilitate the communication of such software. A transmission medium is a machine-readable medium.

[0132] Various embodiments are shown in the figures above. One or more features from one or more of these embodiments can be combined to form other embodiments. The method examples described herein can be at least partially machine or computer-implemented. Some examples can include a computer-readable medium or a machine-readable medium encoded with instructions that are operable to configure an electronic device or system to perform the methods described as above in the examples. Implementations of such methods can include code, such as microcode, assembly language code, or high-level language code, etc. Such code can include computer-readable instructions for performing various methods. The code can form part of a computer program product. Further, the code can be tangibly stored on one or more volatile or non-volatile computer-readable media during execution or at other times.

[0133] The above detailed description is intended to be illustrative and not restrictive. Accordingly, the scope of the present disclosure should be determined with reference to the appended claims together with the full scope of equivalents to which such claims are entitled under the law.

Claims

1. A medical device system, comprising: a stimulation circuit configured to generate first and second stimulation signals in different respective first and second stimulation modes, the first and second stimulation signals being configured to be provided to a patient's heart; a signal receiver circuit configured to receive physiological information of the patient, the physiological information including at least one of thoracic impedance information or respiratory information; and an evaluation circuit configured to control a transition of the stimulation circuit between the first and second stimulation modes, including for: using the received physiological information from a first time period to determine a patient metric; and controlling the transition of the stimulation circuit between the first stimulation mode and the second stimulation mode based on the determined patient metric.

2. The system according to claim 1, wherein the first time period occurs when the stimulation circuit is in the first stimulation mode, and Among them, controlling the transition between the first and second stimulation modes includes: controlling the transition from the first stimulation mode to the second stimulation mode based on the determined patient metric.

3. The system according to claim 2, wherein The evaluation circuit is configured to control an implementation of the first stimulation mode at a first time, wherein the first time period occurs after the first time, and wherein, controlling the transition of the stimulation circuit from the first stimulation mode to the second stimulation mode occurs at a second time after the first time period.

4. The system according to claim 3, wherein, Controlling the transition of the stimulation circuit from the first stimulation mode to the second stimulation mode at the second time includes: comparing the determined patient metric with a threshold; if the determined patient metric exceeds a first threshold, transitioning the stimulation circuit from the first stimulation mode to the second stimulation mode; and if the determined patient metric does not exceed the first threshold, retaining the stimulation circuit in the first stimulation mode.

5. The system according to any one of claims 1 to 4, wherein the first stimulation mode includes a cardiac resynchronization therapy (CRT) mode, the CRT mode being configured to generate a stimulation signal to at least one of a single electrode in a first chamber of the heart or a single electrode in a second chamber of the heart to be delivered, and Among them, the second stimulation mode includes a multi-site pacing (MSP) mode, the MSP mode being configured to generate a stimulation signal to a plurality of electrodes in one of the first or second chambers of the heart to be delivered.

6. The system according to claim 5, wherein the CRT mode is configured to generate a biventricular pacing signal to a single electrode in each of the right ventricle and the left ventricle of the heart to be delivered, and Among them, the MSP treatment mode is configured to generate a stimulation signal to a plurality of electrodes in the left ventricle of the heart to be delivered.

7. The system according to claim 1, wherein the first time period occurs when the stimulation circuit is in the second stimulation mode, and Among them, controlling the transition between the first and second stimulation modes includes: controlling the transition from the second stimulation mode to the first stimulation mode based on the determined patient metric.

8. The system according to any one of claims 1 to 7, wherein the thoracic impedance information includes intrathoracic impedance (ITTI) information, and Among them, the respiratory information includes rapid shallow breathing index (RSBI) information.

9. The system according to claim 8, wherein the evaluation circuit is configured to determine the patient metric according to the following function: the ITTI information; and the RSBI information.

10. The system according to any one of claims 1 to 7, wherein the respiratory information includes a measured value of tidal volume (TV).

11. A method, comprising: using a stimulation circuit to generate first and second stimulation signals in different corresponding first and second stimulation modes, the first and second stimulation signals being configured to be provided to a patient's heart; using a signal receiver circuit to receive the patient's physiological information, the physiological information including at least one of thoracic impedance information or respiratory information; and using an evaluation circuit to control the transition of the stimulation circuit between the first and second stimulation modes, including: using the received physiological information from a first time period to determine a patient metric; and controlling the transition of the stimulation circuit between the first stimulation mode and the second stimulation mode based on the determined patient metric.

12. The method according to claim 11, wherein the first time period occurs when the stimulation circuit is in the first stimulation mode, and wherein controlling the transition between the first and second stimulation patterns comprises: controlling the transition from the first stimulation mode to the second stimulation mode based on the determined patient metric.

13. The method according to claim 12, comprising: controlling the implementation manner of the first stimulation mode at a first time, wherein the first time period occurs after the first time, wherein controlling the transition of the stimulation circuit from the first stimulation mode to the second stimulation mode includes performing it at a second time after the first time period.

14. The method according to claim 13, wherein controlling the transition of the stimulation circuit from the first stimulation mode to the second stimulation mode at the second time includes: comparing the determined patient metric with a threshold; if the determined patient metric exceeds a first threshold, converting the stimulation circuit from the first stimulation mode to the second stimulation mode; and if the determined patient metric does not exceed the first threshold, retaining the stimulation circuit in the first stimulation mode.

15. The method according to any one of claims 11 to 14, wherein the first stimulation mode includes a cardiac resynchronization therapy (CRT) mode, the CRT mode being configured to generate a stimulation signal to be delivered to at least one of a single electrode in a first chamber of the heart or a single electrode in a second chamber of the heart, and Among them, the second stimulation mode includes a multi-site pacing (MSP) mode, the MSP mode being configured to generate a stimulation signal to be delivered to multiple electrodes in one of the first or second chambers of the heart.

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