阅读说明：本技术 心力衰竭治疗的动态控制 (Dynamic control of heart failure treatment ) 是由 戴维·J·特恩斯 喻映红 詹森·汉弗莱 大卫·L·佩什巴赫 迈克尔·詹姆斯·迪弗雷纳 亚当 于 2018-06-13 设计创作，主要内容包括：讨论了用于监视和治疗具有心力衰竭(HF)的患者的系统和方法。该系统可以感测心脏信号,并接收有关患者生理或功能状况的信息。可以创建多种患者生理或功能状况下的包括房室延迟(AVD)或其他定时参数的推荐值的刺激参数表。该系统可以周期性地重新评估患者生理或功能状况。治疗编程器电路可以基于患者状况在仅左心室起搏和双心室起搏之间动态切换,或在单部位起搏和多部位起搏之间切换。治疗编程器电路可以使用心脏信号输入和存储的刺激参数表来调整AVD和其他定时参数。可以根据确定的刺激部位、刺激模式和刺激定时来递送HF治疗。(Systems and methods for monitoring and treating patients with Heart Failure (HF) are discussed. The system may sense cardiac signals and receive information about a patient's physiological or functional condition. A stimulation parameter table may be created that includes recommended values for atrioventricular delay (AVD) or other timing parameters for a variety of patient physiological or functional conditions. The system may periodically re-assess the patient's physiological or functional condition. The therapy programmer circuit may dynamically switch between left ventricular only pacing and biventricular pacing, or between single site pacing and multi-site pacing based on the patient condition. The therapy programmer circuit may use the cardiac signal input and the stored stimulation parameter table to adjust the AVD and other timing parameters. HF therapy can be delivered according to the determined stimulation site, stimulation pattern, and stimulation timing.)

1. A system, comprising:

a stimulator circuit configured to deliver stimulation to the heart using a first atrioventricular delay (AVD) parameter; and

a stimulation control circuit configured to:

increasing the first AVD parameter until a spurious fused beat is detected in the first patient condition;

estimating a first intrinsic atrioventricular interval using the adjusted first AVD parameter and a predetermined offset at the time of detection of the pseudo-fused beat; and is

Determining a second AVD parameter from the estimated first intrinsic atrioventricular interval;

wherein the stimulator circuit is configured to deliver cardiac stimulation using the second AVD parameter.

2. The system of claim 1, wherein the stimulation control circuitry is configured to determine the predetermined offset using a difference between a second intrinsic atrioventricular interval and a third AVD parameter, the third AVD parameter corresponding to a false fusion beat detected in a second patient condition.

3. The system of any of claims 1-2, wherein the estimated first intrinsic atrioventricular interval comprises a first interval (AV) between atrial activations and left ventricular sense events_L) Or a second interval (AV) between atrial activation and right ventricular sensed events_R) And wherein the stimulus control circuit is configured to use AV_LAnd AV_RTo determine the secondTwo AVD parameters.

4. The system of claim 3, wherein the AV is used_LAnd said AV_RTo determine the second AVD parameter.

5. The system of claim 3, wherein the second AVD parameter is further determined using an inter-ventricular interval between the left ventricular sensed event and the right ventricular sensed event.

6. The system of any of claims 1-5, wherein the second AVD parameter comprises a pacing AVD parameter determined for Atrial Sensed (AS) events.

7. The system of any of claims 1-6, wherein the second AVD parameter comprises a sensed AVD parameter determined for an atrial pacing (AS) event.

8. The system of any of claims 1-7, wherein the second AVD parameter corresponds to the first patient condition comprising a heart rate or a heart rate range.

9. The system of any of claims 1-8, wherein the second AVD parameter corresponds to the first patient condition comprising a patient posture.

10. The system of claim 9, wherein the patient position comprises a supine position, a sitting position, or a standing position.

11. The system of any of claims 1-10, wherein the second AVD parameter corresponds to a time of day.

12. The system of any of claims 1-11, wherein the stimulation control circuitry is configured to store the second AVD parameter corresponding to a first patient condition in memory.

13. The system of any of claims 1-12, wherein the stimulation control circuitry is configured to generate a stimulation parameter table that includes AVD parameters for AS events and AP events and corresponding to one or more of heart rate or heart rate range or patient posture.

14. The system of claim 13, wherein the stimulation control circuit is configured to dynamically update at least a portion of the stimulation parameter table using intrinsic atrioventricular spacing.

15. The system of any of claims 13-14, wherein the stimulation control circuitry is configured to dynamically update at least a portion of the stored stimulation parameter set in response to an amount of pacing therapy delivered over a particular time period.

Technical Field

This document relates generally to medical systems and devices, and more particularly to systems, devices, and methods of electrical stimulation for treating heart failure.

Background

Congestive Heart Failure (CHF) is a major lethal cause in the united states and globally. CHF occurs when the heart is unable to adequately supply enough blood to maintain a healthy physiological state. CHF can be treated by drug therapy or electrical stimulation therapy.

Implantable Medical Devices (IMDs) have been used to monitor CHF patients and manage heart failure in a flow (album) setting. Some IMDs may include sensors to sense physiological signals from a patient and detect worsening heart failure (such as heart failure decompensation). Frequent patient monitoring and early detection of worsening heart failure may help to improve patient prognosis. Identifying patients at higher risk for future heart failure events may help provide timely treatment and prevent or reduce hospitalization. Identifying and safely managing patients at risk for worsening heart failure may avoid unnecessary medical intervention, hospitalization, and reduce healthcare costs.

IMDs may include pulse generators and circuits configured to electrically stimulate the heart or other excitable tissue to help restore or improve cardiac function, or correct cardiac arrhythmias. One example of electrical stimulation therapy is Cardiac Resynchronization Therapy (CRT). CRT, typically delivered in the form of Biventricular (BiV) pacing or synchronized Left Ventricular (LV) only pacing, may indicate CHF patients with moderate to severe symptoms and ventricular dyssynchrony. CRT maintains synchronized pumping of the LV and Right Ventricle (RV) by sending electrical stimulation to both the LV and RV. Synchronized stimulation may improve the cardiac pumping efficiency and increase blood flow in certain CHF patients. CRT can reduce hospitalization and morbidity associated with worsening heart failure, as well as improve quality of life.

Disclosure of Invention

Ambulatory Medical Devices (AMD), such as IMDs, subcutaneous medical devices, wearable medical devices, or other external medical devices, may be used to detect worsening heart failure and deliver Heart Failure (HF) therapy to restore or improve cardiac function. The IMD may be coupled to an implanted lead having electrodes that may be used to sense cardiac activity or deliver HF therapy (such as cardiac electrical stimulation). AMD can function as a programmable therapy that allows for manual or automatic adjustment of electrical stimulation parameters (such as stimulation chamber or site, stimulation pattern, or stimulation timing).

AMD can be configured to stimulate various heart chambers to restore cardiac synchrony and improve hemodynamics. During CRT or BiV pacing, synchronized stimulation may be applied to the LV and RV of the heart. RV and LV pacing sites may be stimulated simultaneously, or sequentially by RV-LV interventricular pacing delay (VVD). Delivery of LV pacing and RV pacing may be timed relative to a reference point, such AS an intrinsic atrial depolarization sensed by an atrial electrode (atrial sense or AS) or an atrial pacing pulse (AP) causing atrial activation. LV pacing and RV pacing may be delivered at the end of an atrial-ventricular delay (AVD) if intrinsic ventricular depolarization is not detected within a period of AVD following the AS or AP.

As an alternative to BiV pacing, stimulation may be delivered at only one heart chamber (such as the LV). Such LV-only pacing may provide satisfactory synchrony and cardiac function in certain patients, such as those with intact Atrioventricular (AV) conduction that require cardiac resynchronization. LV-only pacing may require a simpler implantation procedure, consume less power, and provide increased battery life compared to BiV pacing. Thus, it is a clinically effective alternative to the more complex BiV treatment regimen (regime). Similar to the timing of BiV pacing, if an intrinsic LV depolarization is not detected within an AVD period, LV pacing may be delivered at the end of a programmed AVD following an AS or AP.

The AMD can be configured to stimulate one or more sites of the heart chamber simultaneously or sequentially. In conventional Single Site Pacing (SSP), only one site of a particular heart chamber (e.g., LV) is stimulated. Alternatively, multi-site pacing (MSP) may be used as an alternative to SSP. MSP involves electrical stimulation at two or more sites in the heart chamber over the cardiac cycle. For example, in LV MSP, multiple LV sites may be stimulated simultaneously, or at intervals of one or more intra-LV time offsets (ILVD). MSP can improve LV function and hemodynamic response in certain patients. MSPs, however, may require more energy than SSPs and may also increase the complexity of system design and operation. Not all CHF patients consistently receive more benefit from MSP than SSP.

Stimulation timing parameters (e.g., AVD, VVD, or ILVD) define the timing and sequence of cardiac stimulation and may have an effect on the therapeutic effect and hemodynamic outcome. A stimulation timing parameter, such AS AVD, may be determined using measurements of patient AV conduction, such AS an interval (PRI) measured from a surface Electrocardiogram (ECG) between P-waves and R-waves over a cardiac cycle, or an interval (AVI) measured from an intracardiac Electrogram (EGM) between atrial-sensed (AS) or atrial-paced (AP) events and ventricular-sensed events (VS) over a cardiac cycle, for example. In a patient, the PRI or AVI may not remain constant, but may change under a variety of physiological or functional conditions. For example, factors such as long term changes in the patient's health status, HF progression (such as remodeling or decompensation), or short term changes in heart rate, posture changes, physical activity, sleep/awake state, medication, hydration, diet may affect PRI or AVI. Thus, stimulation timing parameters such as AVD may also be affected by long-term or short-term changes in patient condition. Thus, HF therapy based on previously optimized AVD (e.g., LV-only pacing, BiV pacing, SSP, or MSP) may no longer be effective or provide satisfactory patient prognosis under different patient conditions. For example, when a patient changes posture, the programmed AVD may be too long, resulting in reduced or decreased optimal CRT delivery, thereby adversely affecting patient prognosis.

The present inventors have recognized a number of technical challenges for use in electrical stimulation treatment of HF. One of the challenges is related to personalized HF therapy, particularly the adverse effects of varying patient conditions on the efficacy of the therapy. In addition to inter-patient differences in response to LV-only pacing and BiV pacing and inter-patient differences in response to MSP and SSP, there are intra-patient variations in response to LV-only pacing or BiV pacing or in response to SSP or MSP over time, at least due to the effects of long-term or short-term variations in patient physiological or functional conditions. Another challenge relates to ensuring proper pacing therapy, particularly in patients who rely on pacing. For example, CRT pacing decreases may occur in various situations in conventional HF management systems, such as during therapy optimization. Some conventional systems may reconfigure a pacing electrode (e.g., an LV pacing electrode) to sense cardiac electrical activity. Pacing therapy may have to be suspended (albeit temporarily) in order to provide event sensing during therapy optimization. For example, when there is a changing patient condition, frequent re-assessment of PRI or AVI may require that the pacing electrodes be reconfigured as sensing electrodes to sense ventricular activation. Pacing is suspended to frequently reassess PRI or AVI, even temporarily, may adversely affect patient prognosis. Frequent electrode reconfiguration may also increase computational resource costs, such as firmware cycles, and shorten battery life.

This document discusses, among other things, a patient management system for monitoring and treating patients with heart failure. The system may include: a sensor circuit for sensing a cardiac signal; and a receiver for receiving information about a patient's physiological or functional condition, such as posture and physical activity. Stimulation timing parameters under specific patient physiological or functional conditions may be determined and stored in memory. The system may periodically re-assess the patient's physiological or functional condition. The therapy programmer circuit may dynamically determine one or more of stimulation site, stimulation mode, or stimulation timing for a particular patient condition using sensor inputs and stored stimulation timing parameter values. The system may include therapy circuitry for delivering or adjusting electrical stimulation therapy in accordance with the determined stimulation site, stimulation pattern, and stimulation timing.

This document provides a technical solution to the above-identified challenges in electrical stimulation therapy for HF and thus improves the medical technology of device-based heart failure patient management. This document provides, among other things, methods for providing cardiac pacing therapy tailored to individual patients and specific patient physiological or functional conditions (e.g., by programming therapy parameters including stimulation timing, stimulation site, and stimulation pattern). This document discusses an efficient method of adjusting AVD or other stimulation timing parameters based on a stimulation parameter table containing recommended AVD values for a variety of patient conditions. The adjustment of the stimulation timing for patient condition indication, along with the dynamic switching between LV-only pacing and BiV and between SSP and MSP pacing modes, can ensure consistent and effective pacing therapy that meets the needs of individual patients under different physiological or functional conditions. In one example, this document provides beat-to-beat adjustment of stimulation timing and switching of stimulation sites or stimulation modes. The systems and methods discussed herein can improve treatment efficacy, patient prognosis, and reduce healthcare costs associated with HF management. This document also provides for the identification of conditions that may affect stimulation timing and treatment effectiveness. This may be beneficial for healthcare providers to track patient HF progression and improve patient management.

This document also discusses a method of estimating a PRI or AVI during stimulation using an offset between an AVD and the PRI or AVI corresponding to a pseudofusion (pseudofusion) beat. Since the estimation process does not require pacing to be suspended, adequate pacing therapy can be achieved even during therapy adjustments; and adverse effects on the patient's prognosis can be avoided or reduced.

In addition to improving the medical techniques of device-based heart failure patient management in various patient conditions, the systems, devices, and methods discussed herein may also allow for more efficient device memory usage, such as by storing and updating stimulation timing parameters that are clinically more relevant to patient long-term and short-term changing conditions. The individualized and dynamically adjusted treatment discussed in this document may not only improve treatment outcome and patient prognosis, but may also conserve device power and extend battery life. By individualizing HF therapy tailored to a particular patient condition, fewer unnecessary interventions or hospitalizations may be scheduled, prescribed, or provided; as a result, overall cost savings may be realized.

This summary is an overview of some of the teachings of the present application and is not intended to be an exclusive or exhaustive treatment of the present subject matter. Additional details regarding the present subject matter are found in the detailed description and appended claims. Still other aspects of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description and viewing the drawings that form a part hereof, each of which is not to be taken in a limiting sense. The scope of the invention is defined by the appended claims and their legal equivalents.

Drawings

Various embodiments are illustrated by way of example in the figures of the accompanying drawings. These embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present subject matter.

Figure 1 shows an example of a patient management system and an example of a portion of an environment in which the system may operate.

Fig. 2 shows an example of a dynamically controlled cardiac stimulation system configured to program and deliver electrical stimulation to treat HF or other cardiac disorders.

Fig. 3A-3B illustrate examples of stimulation parameter tables including recommended values for stimulation timing under various patient physiological and physical conditions.

Fig. 4A-B illustrate examples of methods for initializing and updating a stimulation parameter table.

Fig. 5 shows an example of a method for dynamically determining PRI or AVI during pacing.

Fig. 6 shows an example of a method for determining between LV-only pacing and BiV pacing.

Fig. 7 shows an example of a method for determining between SSP pacing and MSP.

Fig. 8 illustrates a block diagram of an example machine on which any one or more of the techniques (e.g., methods) discussed herein may be executed.

Detailed Description

Disclosed herein are systems, devices, and methods for monitoring and treating patients with heart failure or other cardiac disorders. The system may sense cardiac signals and receive information about a patient's physiological or functional condition. A stimulation parameter table including recommended values for timing parameters such as AVD may be created under a variety of patient physiological or functional conditions. The system may periodically re-assess the patient's physiological or functional condition. The therapy programmer circuit may dynamically switch between LV-only pacing and BiV pacing, between single-site pacing and multi-site pacing, or adjust stimulation timing using cardiac signal inputs and a table of stimulation parameters based on patient condition. HF therapy can be delivered according to the determined stimulation site, stimulation pattern, and stimulation timing.

HF monitorVision and therapy system and device

Fig. 1 shows an example of a patient management system 100 and portions of an environment in which the patient management system 100 may operate. The patient management system 100 may include: an ambulatory medical device, such as an Implantable Medical Device (IMD)110, which may be electrically coupled to the heart 105 by one or more leads 108A-C; and an external system 120 that can communicate with the IMD110 via a communication link 103. Examples of the IMD110 may include, but are not limited to, pacemakers, defibrillators, Cardiac Resynchronization Therapy (CRT) devices, cardiac Remodeling Control Therapy (RCT) devices, neuromodulators, drug delivery devices, biological therapy devices, diagnostic devices such as cardiac monitors or cycle recorders, or patient monitors, among others. The IMD110 may be coupled to or may be replaced by a monitoring medical device, such as a bedside or other external monitor. Other ambulatory medical devices may be used in addition to or in place of the IMD110, which may include: a subcutaneous medical device such as a subcutaneous monitor or diagnostic device; or an external monitoring or therapy medical device such as an Automated External Defibrillator (AED) or holter monitor; a wearable medical device such as a patch-based device, a smart watch, or a smart accessory; or a bedside monitor.

The IMD110 can include a hermetically sealed container 112 that can house electronic circuitry that can sense physiological signals in the heart 105 and can deliver one or more therapeutic electrical pulses, such as through one or more leads 108A-C, to a target area, such as in the heart. The patient management system 100 may include only one lead (such as 108B), or may include two leads (such as 108A-B).

The lead 108A may include: a proximal end that may be connected to the IMD 110; and a distal tip that may be placed at a target location, such as in the Right Atrium (RA)131 of the heart 105. Lead 108A may have a first pacing sensing electrode 141, which may be located at or near its distal end, and a second pacing sensing electrode 142, which may be located at or near electrode 141. Electrodes 141 and 142 may be electrically connected to IMD110, such as via separate conductors in lead 108A, to allow sensing of right atrial activity and optional delivery of atrial pacing pulses. Lead 108B may be a defibrillation lead, which may include: a proximal end that may be connected to the IMD 110; and a distal end that may be placed at a target location, such as in the Right Ventricle (RV)132 of the heart 105. The lead 108B may have: a first pacing sensing electrode 152, which may be located at the distal end; a second pacing sensing electrode 153, which may be located near electrode 152; a first defibrillation coil electrode 154, which may be located near the electrode 153; and a second defibrillation coil electrode 155 that may be located at a distance from the distal end for Superior Vena Cava (SVC) placement. The electrodes 152-155 may be electrically connected to the IMD110, such as via separate conductors in the lead 108B. Electrodes 152 and 153 may allow sensing of ventricular EGMs and may optionally allow delivery of one or more ventricular pacing pulses, and electrodes 154 and 155 may allow delivery of one or more ventricular cardioversion/defibrillation pulses. In one example, lead 108B may include only three electrodes 152, 154, and 155. Electrodes 152 and 154 may be used to sense or deliver one or more ventricular pacing pulses, and electrodes 154 and 155 may be used to deliver one or more ventricular cardioversion or defibrillation pulses. The lead 108C may include: a proximal end that may be connected to the IMD 110; and a distal tip that may be placed at a target location, such as in the Left Ventricle (LV)134 of the heart 105. Lead 108C may be implanted through coronary sinus 133 and may be placed in a coronary vein above the LV to allow delivery of one or more pacing pulses to the LV. The lead 108C may include: an electrode 161, which may be located at the distal end of the lead 108C; and another electrode 162, which may be located near electrode 161. Electrodes 161 and 162 may be electrically connected to IMD110, such as via separate conductors in lead 108C, to allow sensing of the LV EGM and optionally to allow delivery of one or more resynchronization pacing pulses from the LV. Additional electrodes may be included in lead 108C or along lead 108C. As shown in fig. 1, in one example, the third electrode 163 and the fourth electrode 164 may be included in the lead 108. In some examples (not shown in fig. 1), at least one of the leads 108A-C or additional leads other than the leads 108A-C may be implanted beneath the skin surface and not within at least one heart chamber, or at or near the heart tissue.

The IMD110 may include circuitry that may sense physiological signals. The physiological signals may include EGMs or signals indicative of mechanical function of heart 105. The hermetically sealed container 112 may be used as an electrode, such as for sensing or pulse delivery. For example, electrodes from one or more of leads 108A-C may be used with container housing 112, such as for unipolar sensing of EGMs or for delivering one or more pacing pulses. Defibrillation electrodes from lead 108B may be used with reservoir housing 112, such as for delivering one or more cardioversion/defibrillation pulses. In one example, the IMD110 may sense an impedance, such as an impedance between electrodes located on one or more of the leads 108A-C or the container housing 112. The IMD110 may be configured to inject a current between a pair of electrodes, sense the resulting voltage between the same or different pair of electrodes, and determine an impedance using ohm's law. The impedance may be sensed in the following configuration: a bipolar configuration, where the same electrode pair can be used for both injection current and sensing voltage; a three-pole configuration, in which the electrode pair for current injection and the electrode pair for voltage sensing may share a common electrode; or a quadrupole configuration, where the electrodes for current injection may be different from the electrodes for voltage sensing. In one example, IMD110 may be configured to inject a current between an electrode on RV lead 108B and container housing 112 and sense a resulting voltage between the same electrode on RV lead 108B and container housing 112 or a resulting voltage between a different electrode on RV lead 108B and container housing 112. The physiological signals may be sensed from one or more physiological sensors that may be integrated within the IMD 110. The IMD110 may also be configured to sense physiological signals from one or more external physiological sensors or one or more external electrodes that may be coupled to the IMD 110. Examples of physiological signals may include one or more of ECG, intracardiac EGM, heart rate variability (variabilty), intrathoracic impedance, intracardiac impedance, arterial pressure, pulmonary artery pressure, left atrial pressure, RV pressure, LV coronary pressure, coronary blood temperature, blood oxygen saturation, one or more heart sounds, physical activity or exertion level, physiological response to activity, posture, respiration, weight or body temperature, and the like.

In some examples, system 100 may include one or more leadless sensors tethered to IMD110 not via leads 108A-C. The leadless flow sensor may be configured to sense physiological signals and wirelessly communicate with the IMD 110. In some examples, the IMD110 may be a leadless medical device. Unlike tethered devices such as IMD110 (tethered devices) as shown in fig. 1, leadless medical devices do not require leads, or tethers to extend between the electrodes and the device body. The leadless medical device may include an anchoring or fixation mechanism for positioning the device body on a target implantation side, such as an epicardial surface of one of the left ventricle, right ventricle, left atrium, or right atrium, or an epicardial surface of a portion of the heart. A leadless medical device may be delivered intravenously and positioned within a vessel on the heart (such as a coronary vein), where one or more electrodes on the leadless medical device may be in direct or indirect contact with an epicardial surface of the heart. Examples of such leadless medical devices may include the Leadless Cardiac Pacemaker (LCP) disclosed in U.S. patent application publication 2016/0051823, entitled "LEADLESS CARDIACPACEMAKER HAVING A SENSOR WITH a LOWER POWER MODE," commonly assigned to Maile et al, the entire contents of which are incorporated herein by reference.

The arrangement and function of these leads and electrodes are described above by way of example and not limitation. Other arrangements and uses of these leads and electrodes are possible depending on the needs of the patient and the capabilities of the implantable device.

The patient management system 100 may include a dynamically controlled stimulation circuit 113. The dynamically controlled stimulation circuit 113 may dynamically determine the treatment parameters based on the current physiological or functional condition of the patient. Patient conditions (such as patient health, HF progression, remodeling or decompensation, heart rate, posture changes, physical activity, sleep/awake state, medication, hydration, diet, etc.) may affect cardiac electrical and mechanical properties, and thus HF therapeutic efficacy. In one example, the dynamically controlled stimulation circuit 113 may determine a stimulation site based on sensor inputs (such as determining between LV-only pacing and BiV pacing), or determine a stimulation mode (such as determining between SSP and MSP). The dynamically controlled stimulation circuit 113 may further use sensor inputs and optionally a predetermined stimulation parameter table to determine stimulation timing (such as AVD or VVD values). The stimulation parameter table contains timing values (e.g., AVD values) under various patient physical and physiological conditions. Dynamically controlled stimulation circuitry 113 may deliver electrical stimulation to the heart in accordance with the determined stimulation site, stimulation mode, and stimulation timing parameters. An example of a dynamically controlled stimulation circuit 113 is described below, such as with reference to fig. 2.

The external system 120 may allow the IMD110 to be programmed via the communication link 103 and receive information from the IMD 110. External system 120 may include a local external IMD programmer. The external system 120 may include a remote patient management system that may monitor patient status or adjust one or more treatments, such as from a remote location. The remote patient management system may, among other possible functions, evaluate the collected patient data and provide an alert notification. In one example, the remote patient management system may include a central server that acts as a central hub for the storage and analysis of collected patient data. The server may be configured as a single computing and processing system, a multiple computing and processing system, or a distributed computing and processing system. The remote patient management system may additionally or alternatively include one or more locally configured clients or remote clients securely connected to a server. Examples of clients may include personal desktops, notebook computers, mobile devices, or other computing devices. A system user (such as a clinician or other qualified medical professional) may securely access stored patient data in a database collected in a server using a client.

The communication link 103 may include one or more of an inductive telemetry link, a radio frequency telemetry link, or a telecommunications link, such as an internet connection. The communication link 103 may provide for data transfer between the IMD110 and the external system 120. The data transmitted may include: for example, real-time physiological data acquired by the IMD110, physiological data acquired by the IMD110 and stored in the IMD110, therapy history data or data indicative of an operating state of the IMD, programming instructions to the IMD110 to configure the IMD110 to perform one or more actions (including, for example, data acquisition, device self-diagnostic testing, or therapy delivery).

The dynamically controlled stimulation circuit 113 may be implemented at the external system 120, such as using data extracted from the IMD110 or data stored in a memory within the external system 120. Portions of the dynamically controlled stimulation circuitry 113 may be distributed between the IMD110 and the external system 120.

Portions of the IMD110 or the external system 120 may be implemented using hardware, software, or any combination of hardware and software. Portions of the IMD110 or the external system 120 may be implemented using dedicated circuitry that may be constructed or configured to perform one or more particular functions or may be implemented using general-purpose circuitry that may be programmed or otherwise configured to perform one or more particular functions. Such a general circuit may include: a microprocessor or a part thereof, a microcontroller or a part thereof, or a programmable logic circuit or a part thereof. For example, a "comparator" may include, among other things, an electronic circuit comparator that may be configured to perform a particular comparison function between two signals, or the comparator may be implemented as part of a general purpose circuit that may be driven by code that instructs a portion of the general purpose circuit to perform a comparison between two signals. Although described with reference to IMD110, patient management system 100 may include a subcutaneous medical device (e.g., subcutaneous ICD, subcutaneous diagnostic device), a wearable medical device (e.g., patch-based sensing device), or other external medical device.

Fig. 2 shows an example of a dynamically controlled cardiac stimulation system 200. The dynamically controlled cardiac stimulation system 200 may be configured to provide diagnostic information including, for example, changes in cardiac state under various patient physiological or functional conditions, and recommend values of treatment parameters such as timing, location, and pattern of cardiac electrical stimulation. The dynamically controlled cardiac stimulation system 200 may include one or more of a cardiac sensor circuit 210, a patient condition receiver 220, a therapy programmer circuit 230, a storage circuit 240, a controller circuit 250, and a user interface 260. In some examples, the dynamically controlled cardiac stimulation system 200 may additionally include therapy circuitry 270 that may deliver or adjust therapy such as cardiac electrical stimulation. At least a portion of the cardiac monitoring system 200 may be implemented in the AMD, such as the IMD110, or distributed between the AMD and an external system, such as the external system 120.

The cardiac sensor circuit 210 may include a sense amplifier to sense cardiac signals. Cardiac signals may be sensed from different heart chambers such as one or more of the RA, RV, Left Atrium (LA), or LV. A cardiac signal may be sensed when the heart experiences an intrinsic rhythm, such as a sinus rhythm, or when the heart is stimulated according to a stimulation protocol, such as pacing at an atrium, ventricle, or other site at a particular frequency or timing sequence. Examples of cardiac signals may include cardiac electrical signals, such as an ECG non-invasively sensed from a body surface, a subcutaneous ECG sensed from subcutaneously placed electrodes, or an intracardiac EGM sensed from one or more of leads 108A-C or electrodes on container housing 112. By way of example and not limitation, atrial activation (represented by AS) may be sensed using a sensing vector that includes one of atrial electrodes 141 or 142, right ventricular activation (represented by RVs) may be sensed using a sensing vector that includes one of RV electrodes 152 and 154, and left ventricular activation (represented by LVs) may be sensed using a sensing vector that includes one of LV electrodes 161 and 164.

Additionally or alternatively, the cardiac signal may comprise a signal indicative of cardiac mechanical activity or patient hemodynamic status. In one example, the cardiac signal may include a signal sensed from an accelerometer or a microphone configured to sense heart sounds of the patient. In one example, the cardiac signal may include a cardiac or thoracic impedance signal. The cardiac mechanical signal may comprise a blood pressure sensor signal or any other sensor signal indicative of the mechanical activity or hemodynamic state of the heart.

In some examples, the cardiac sensor circuit 210 may sense two or more cardiac signals from different sites of the heart chamber (such as multiple sites at the LV) simultaneously or sequentially. Cardiac sensor circuit 210 may sense LV EGMs from two or more LV sites using respective sensing vectors. Examples of LV sensing vectors may include bipolar sensing vectors, such as between selected pairs of electrodes in 161-164. Alternatively, the LV sensing vector may be between one of the electrodes 161-164 and another electrode positioned on a different chamber or a different lead (such as one of the electrodes 152-155 on RV lead 108B or one of the electrodes 141 or 142 on RA lead 108A). Another example of an LV sensing vector may include a unipolar sensing vector between one of the electrodes 161-164 and the reservoir housing 112, for example.

The cardiac sensor circuit 210 may process (including amplify, digitize, filter, or other signal conditioning operations) the sensed cardiac signal. Based on the processed cardiac signal, the cardiac sensor circuit 210 may detect signal characteristics or perform measurements indicative of the patient's cardiac condition or the effectiveness of the treatment or complications resulting from the stimulation. Examples of signal features may include temporal or morphological features indicative of intrinsic cardiac activity such as P-waves, Q-waves, R-waves, QRS complexes, or T-waves that may be detected from surface ECG, subcutaneous ECG, or intracardiac EGMs, or timing and intensity of induced cardiac activity such as in response to induced electrical or mechanical activation of electrical stimulation to the heart. Examples of intensity measurements may include signal amplitude, slope or rate of change of signal amplitude, amplitude of a transformed physiological signal such as an integrated signal, or frequency domain measurements such as power spectral density. Examples of timing measurements may include time delays between sensed cardiac activations at different heart chambers (e.g., PRI or AVI between the atrium and ventricle, or sensed RV to sensed LV intervals), or time delays between different pacing sites (e.g., sensing delays between various LV sites).

The patient condition receiver 220 may receive information regarding the patient's long-term and short-term physiological or functional conditions. Changes in long-term or short-term patient conditions may affect cardiac electrical and mechanical properties as well as patient hemodynamic response. As a result, if not timely and appropriately adjusted to accommodate changing patient conditions, the treatment may be less effective. Physiological signals, such as cardiac, pulmonary, neural, or biochemical signals, may be received at the patient condition receiver 220. Examples of physiological signals may include blood chemistry measurements or expression levels of ECG, intracardiac EGMs, heart rate signals, heart rate variability signals, cardiovascular pressure signals, heart sound signals, respiration signals, thoracic impedance signals, respiration sound signals, or one or more biomarkers. Examples of functional signals may include patient posture, gait, balance or physical activity signals, etc. The sensor circuit may sense the functional signal using a motion sensor, such as an accelerometer, a gyroscope (which may be a one-, two-, or three-axis gyroscope), a magnetometer (e.g., a compass), an inclinometer, an altimeter, an Electromagnetic Tracking System (ETS), or a Global Positioning System (GPS) sensor, etc. In another example, the functional signal may include information about a sleep state signal, such as a sleep or awake state, a frequency or duration of sleep position transitions, a sleep propensity, or other sleep quality indicator. In another example, the functional signal may include information about food or beverage intake (e.g., swallowing), cough, or inhalation detection. In some examples, information regarding patient physiological or functional conditions may be stored in a storage device, such as an Electronic Medical Record (EMR) system, and the patient condition receiver 220 may be configured to receive patient conditions from the storage device in response to user input or triggered by a particular event.

In some examples, the patient condition receiver 220 may receive information about patient medical history, drug intake, hospitalization, surgery, cardiac remodeling, worsening heart failure events (such as heart failure decompensation or HF complications). In some examples, the patient condition receiver 220 may receive device implant information (such as the location of an implantable lead). For example, the LV lead 108C may be implanted at the free wall, anterior, lateral, or posterior, among other possible LV locations. LV lead location may affect the effectiveness of treatment and is used to determine stimulation site, mode, and timing parameters. In some examples, the patient condition receiver 220 may include patient echocardiographic measurements, such as ejection fraction, cardiac contractility, heart timing, or aortic velocity, among other hemodynamic parameters or other clinical diagnoses.

Therapy programmer circuitry 230 may generate a diagnosis regarding a change in cardiac state under a particular patient physiological or functional condition as received from patient condition receiver 220 and recommend therapy parameter values including, for example, timing, location, and pattern of electrical stimulation of the heart. The therapy programmer circuit 230 may be implemented as part of a microprocessor circuit, which may be a dedicated processor, such as a digital signal processor, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other type of processor for processing information including physical activity information. Alternatively, the microprocessor circuit may be a general purpose processor that can receive and execute a set of instructions to perform the functions, methods, or techniques described herein.

Therapy programmer circuitry 230 may include a circuit set that includes one or more other circuits or sub-circuits, including one or more of PRI/AVI estimator circuit 235, stimulation site selector circuit 231, stimulation mode selector 232, and stimulation timing adjuster circuit 233. These circuits may perform the functions, methods, or techniques described herein, either alone or in combination. In one example, the hardware of the circuit group may be designed to perform certain operations (e.g., hard-wired) without change. In one example, the hardware of the circuit set may include variably connected physical components (e.g., execution units, transistors, simple circuits, etc.) that include a computer-readable medium physically modified (e.g., magnetically, electrically, movably placing a constant mass of particles, etc.) to encode instructions for a particular operation. In connecting physical components, the basic electrical characteristics of the hardware components are changed, for example, from an insulator to a conductor or vice versa. These instructions enable embedded hardware (e.g., an execution unit or loading mechanism) to create components of a circuit group in the hardware via a variable connection to perform portions of a particular operation when operating. Thus, when the device is operating, the computer readable medium is communicatively coupled to the other components of the circuit group member. In one example, any physical assembly may be used in more than one component of more than one circuit group. For example, in operation, the execution unit may be used in a first circuit group at one point in time and reused by a second circuit in the first circuit group at a different time or reused by a third circuit in the second circuit group.

The stimulation site selector circuit 231 may be configured to determine a heart chamber for pacing from the received patient condition. In one example, the stimulation site selector circuit 231 may select between LV-only pacing and BiV pacing. BiV pacing refers to stimulating both the LV and RV sequentially, either simultaneously or at a specified time offset. In some patients, BiV pacing may provide better cardiac synchrony and cardiac contractility than LV-only pacing configured to stimulate LV only. However, changes in a patient's physiological or functional condition (e.g., an increase in heart rate or a transition from a supine to a standing position) may change the AV state, ventricular contractility, or other cardiac characteristics. The pacing chamber may need to be switched to maintain adequate therapeutic effect, among other therapeutic adjustments. The stimulation site selector circuit 231 may initiate stimulation site evaluation in response to changes in patient condition and make a determination between LV-only pacing and BiV pacing based on an increase in heart rate and an indicator of AV conduction abnormalities, such as an extension of PRI or AVI or an increase in irregularity of PRI or AVI. An example of determining a stimulation site to accommodate a change in a patient's condition between LV-only pacing and BiV pacing is discussed below, such as with reference to fig. 6.

The stimulation mode selector circuit 232 may be configured to determine between Single Site Pacing (SSP) and multi-site pacing (MSP) based on the received patient condition. MSP can be delivered at two or more sites on the epicardial surface or the interior of one or more heart chambers or tissue surrounding any of these chambers. During MSP, pulse trains may be delivered simultaneously at two or more cardiac sites or sequentially with an intra-ventricular delay that is less than a sensing or pacing interval value of a cardiac cycle.

In one example, the stimulation mode selector circuit 232 may initiate stimulation mode evaluation in response to changes in patient conditions and use the inter-ventricular intervals measured from the RV site to various candidate LV sites (such as those corresponding to LV electrodes 161-164) to determine between SSP pacing and MSP pacing at two or more LV sites. The interventricular interval represents the degree of dyssynchrony between the RV and various LV sites. The stimulation pattern selector circuit 232 may scan a plurality of candidate LV electrodes to identify those LV sites having corresponding ventricular intervals that satisfy a specified condition (such as a threshold indicative of patient condition), and select SSP or MSP based on the candidate electrode identification. An example of determining stimulation patterns between SSP and MSP to accommodate changes in patient condition is discussed below, such as with reference to fig. 7.

Stimulation timing adjuster circuit 233 may be configured to determine stimulation timing parameters (e.g., AVD, VVD, or ILVD) based on the received patient condition. The stimulation timing parameters define the timing sequence of cardiac activation and may affect the therapeutic effect and patient hemodynamic response. In one example, stimulation timing adjuster circuit 233 may use the PRI or AVI to determine the AVD under the received patient condition. As previously discussed, the PRI or AVI may vary under a variety of patient physiological or functional conditions. PRI or AVI may be measured directly from sensed cardiac signals under specific patient conditions. Alternatively, the PRI or AVI may be estimated dynamically during pacing, such as provided by the PRI/AVI estimator circuit 235.

The AVD may be determined AS a linear combination of the interval between Atrial Sensing (AS) or Atrial Pacing (AP) activation and sensing RV activation (RVs) and the interval between AS or AP and sensing LV activation (LVs). Alternatively, AVD values for various patient conditions may be dynamically created and stored in the memory circuit 240. Graphically, the AVD values may be organized in a stimulation parameter table, such as depicted below in fig. 3A-3B. Stimulation timing adjuster circuit 233, which is coupled to memory circuit 240, can search the received patient condition from the stimulation parameter table and identify a recommended AVD corresponding to the patient condition. Stimulation timing adjuster circuit 233 may perform dynamic AVD adjustment by switching to the applicable table entry whenever the patient is in that condition. In one example, the AVD may be adjusted on a beat-by-beat basis. Examples of using the stimulation parameter table for patient condition indication to adjust the AVD are discussed below, such as with reference to fig. 3-4.

The PRI/AVI estimator circuit 235 may be configured to dynamically determine the PRI or AVI during pacing. The PRI/AVI estimator circuit 235 may be coupled to one or more of the stimulation site selector circuit 231, the stimulation mode selector circuit 232, or the stimulation timing adjuster circuit 233. The circuitry 231-.

The PRI/AVI estimator circuit 235 may be configured to measure an offset between the AVD and the PRI or AVI corresponding to the spurious fused beat, such as through a test procedure, as will be discussed below with reference to fig. 5. The offset may be stored for future use. When a change in a patient's physiological or functional condition is detected, the combination of the AVD and stored offset that resulted in the spurious fusion can be used to estimate the PRI or AVI. In this way, PRI or AVI may be estimated without suspending ventricular pacing. An example of dynamically determining PRI or AVI during pacing is discussed below, such as with reference to fig. 5.

The therapy circuit 270 may be configured to generate a therapy according to parameter values generated and recommended by the therapy programmer circuit 230. The therapy may include electrical stimulation delivered to the pacing site via one or more of the leads 108A-C and the respective attached electrodes. The therapy circuit 270 may be configured to deliver LV-only pacing or BiV pacing. Additionally or alternatively, the therapy circuit 270 may be configured to generate SSP for stimulating one cardiac site, or MSP for stimulating two or more sites of the heart within the same cardiac cycle. In one example, MSP can be delivered within the LV. The LV MSP may have a unipolar pacing configuration in which only one electrode (e.g., the cathode) is the LV electrode and the other electrode (e.g., the anode) is IMD container housing 112. In another example, a true bipolar configuration may be used, where both the cathode and anode are LV electrodes. In yet another example, an extended bipolar configuration may be used in which one electrode (e.g., the cathode) is the LV electrode and the other electrode (e.g., the anode) is the RA electrode (such as one of electrodes 141 or 142) or the RV electrode (such as one of electrodes 152 and 155). In another example, a tripolar configuration may be used, which may involve two LV electrodes that function together as cathodes, or two electrodes such as selected from RA and RV electrodes that function together as anodes. In some examples, the one or more LV electrodes may be distributed in one or more LV leads, catheters, or tetherless pacing units.

In some examples, the therapy circuitry 270 may initiate or adjust electrical stimulation or other therapy types at non-cardiac tissue (such as neural tissue) such as cardioversion therapy, defibrillation therapy, or drug therapy including delivery of drugs to tissues or organs. In some examples, the therapy circuitry 270 may modify an existing therapy, such as adjusting a stimulation parameter or a drug dose.

The controller circuit 250 may control the operation of the therapy programmer circuit 230, the storage circuit 240, the therapy circuit 270, as well as the data flow and instructions between these components and the respective subcomponents. In one example, the controller circuit 250 may update the stimulation parameter table. The stimulation parameter table may be updated periodically or in response to a triggering event. In some examples, the controller circuit 250 may update the stimulation parameter table at a frequency according to a table update history (such as a trend of table updates) so that a next update may be scheduled according to the historical trend. An example of creating and updating a stimulation parameter table is discussed below, such as with reference to fig. 4. The controller circuit 250 may additionally control the therapy circuit 270 to deliver HF therapy according to the selected stimulation site, stimulation mode, and stimulation timing parameters.

The user interface 260 may include an input device that enables a system user to program parameters for electrical stimulation or for sensing cardiac signals. Examples of input devices may include a keyboard, an on-screen keyboard, a mouse, a trackball, a touchpad, a touch screen, or other pointing or navigation devices. The input device may enable the system user to activate automatic programming of the HF therapy, such as automatically determining stimulation sites, stimulation patterns, and stimulation timing parameters under specific patient conditions. The input device may also enable the system user to confirm, reject, or modify the automatically determined therapy programming.

The user interface 260 may include a display for displaying therapy programming, such as automatically determined stimulation sites, stimulation patterns, and stimulation timing parameters. Output unit 230 may include a printing device for producing a hard copy of the information. Information may be represented in tables, charts, trends, graphs, or any other type of text, table, or graphical presentation format. Additional information for display may include cardiac signals sensed from cardiac sensor circuit 210, signal characteristics or measurements derived from the sensed cardiac signals (e.g., PRI or AVI), information received from patient condition receiver 220 of the patient's physiological or functional condition, or device status information such as lead impedance and integrity, battery status such as remaining life of the battery, or cardiac stimulation thresholds, or complications associated with stimulation at one or more cardiac sites, etc.

Pacing optimization of patient status indication

Fig. 3A-3B illustrate examples of stimulation parameter tables including recommended values for stimulation timing under various patient physiological and physical conditions. Examples of conditions may include posture (e.g., supine, sitting, standing, or transitioning between postures, among other postures), walking, running, sleeping, time of day (e.g., daytime, nighttime, or a particular duration of time of day), diet, hydration, drug intake, heart rate variability, arrhythmic events (e.g., atrial fibrillation, ventricular tachycardia, ventricular premature beats, post-arrhythmia), atrial activation patterns (e.g., atrial pacing or atrial sensing), and so forth. The present inventors have recognized that such conditions, alone or in combination, can affect cardiac tissue properties and patient hemodynamic conditions. As a result, a therapy programmed in one condition may not be as effective in a different condition. Different AVD values may be recommended for use in different patient conditions to achieve a desired therapeutic effect and patient prognosis.

Table 300 shown in fig. 3A and table 350 shown in fig. 3B may each be implemented as a multidimensional array, associative graph, or other data structure for storage in storage circuitry 240. By way of example and not limitation, table 300 includes stimulation timing values (such as AVD values) at particular Heart Rates (HRs) 310, postures 320, and atrial activation patterns 330. HR 310 may be classified into a plurality of HR ranges, posture 320 may include one or more of a supine posture, a seated posture, or a standing posture, and atrial activation pattern 330 may include one or more of Atrial Sensing (AS) and Atrial Pacing (AP) patterns. The AVD for the AS will be referred to hereinafter AS a sensed AVD, and the AVD for the AP will be referred to hereinafter AS a paced AVD. Each entry of table 300 may include a recommended AVD value for the corresponding patient condition. For example, table entry 301 contains recommended paced AVDs, denoted by AVD @, corresponding to heart rates and stance falling within the range of 60-70 bpm. When programming AVD to the therapy circuit, a ventricular pacing pulse may be delivered as atrial pacing at an AVD offset if intrinsic ventricular activity is not detected within a period of AVD. In some examples, table 300 may include stimulation timing values (e.g., AVD values) at a particular Heart Rate (HR)310 and atrial activation mode 330, regardless of the posture of the patient. In other words, gesture 320 may be excluded from table 300. The table 350 shown in fig. 3B includes stimulation timing values (such as AVD values) at a particular HR 310, time of day 340, and atrial activation pattern 330. By way of non-limiting example and as shown in fig. 3B, the time of day 340 may include the day and night. Each entry of table 350 may include a recommended AVD value for the corresponding patient condition. For example, table entry 302 contains recommended paced AVDs, denoted by AVD, corresponding to heart rates falling within the range of 60-70bpm during the night. In one example, time of day 340 may include multiple time periods of the day within a 24 hour period. In various examples, the table 300 or 350 may be augmented to include other conditions. For example, table 300 may include a time of day 340, or table 350 may include information about patient posture 320. The inventors have contemplated that various combinations or permutations of patient conditions (including but not limited to HR 310, posture 320, atrial activation pattern 330, and time of day 340) are implemented in a stimulation parameter table similar to tables 300 or 350, which is within the scope of this document.

In various examples, at least some of the entries of tables 300 or 350 may additionally or alternatively include recommended values for stimulation timing parameters other than AVDs. In one example, the table entry may include a recommended RV-LV delay (VVD) for corresponding patient conditions of heart rate, posture, and atrial activation pattern. VVD represents the offset between LV and RV pacing pulses within a cardiac cycle for BiV pacing or CRT therapy, such as selected by a system user or determined by stimulation site selector circuit 231. In some examples, VVD may be set to zero such that LV pacing and RV pacing are delivered simultaneously. In another example, at least some table entries may include a recommended intra-LV time offset (ILVD). The ILVD represents the offset between LV pacing pulses delivered at different LV sites, respectively, within a cardiac cycle, when the LV MSP is selected by a system user or determined by stimulation mode selector circuit 232. LV MSP may be delivered via two or more of the LV electrodes 161-164 as shown in fig. 1.

Table 300 or table 350 may be augmented to include information in addition to stimulation timing parameters. In one example, at least some entries of tables 300 or 350 may additionally or alternatively include information about the stimulation site (such as an indication of LV-only pacing or BiV pacing), or information about the stimulation mode (such as an indication of SSP or MSP). As discussed above with reference to fig. 2, the choice between LV-only pacing or BiV pacing, or between SSP or MSP, may vary under different patient physical and physiological conditions. Thus, the augmented table 300 or 350 provides comprehensive treatment recommendations for stimulation site, pattern, and timing values in various patient conditions. In an example, the entries of the augmented table 300 or 350 may be constructed as class structures in the storage circuit 240 that contain values for one or more of stimulation site, mode, and timing parameters. For example, one table entry may include (AVD, LV-only pace) and another table entry may include (AVD, BiV pace, VVD, MSP, ILVD). In one example, one element of a table entry (e.g., AVD value, BiV pacing, or MSP) may apply to multiple table entries sharing a common condition. For example, if BiV pacing is recommended for conditions defined by sitting posture, AS, and HR greater than 100bpm, BiV pacing may be recommended for all conditions regardless of heart rate range or atrial activation pattern (AS or AP) AS long AS the "sitting" posture is involved. In another example, if MS is recommended for a condition defined by stance, AS and HR at 70-80bpm, MSP can be recommended for all conditions regardless of heart rate range or atrial activation pattern, so long AS a "stance" is included.

In some examples, multiple tables of stimulation timing parameter values may be constructed and stored in the memory circuit 240, such as an AVD table containing only AVD values for various patient conditions, a VVD table containing only VVD values for various patient conditions, or an ILVD table containing only ILVD values for various patient conditions. The table may include different patient physiological or functional conditions. In one example, when BiV pacing is selected, such as via the stimulation site selector circuit 231, the stimulation timing adjuster circuit 233 may reference a VVD table to determine an optimal VVD value for a particular patient condition. In another example, when the MSP mode is selected, such as via the stimulation mode selector circuit 232, the stimulation timing adjuster circuit 233 may reference the ILVD table to determine an optimal ILVD value for a particular patient condition. Stimulation timing adjuster circuit 233 may reference the AVD table independently of the selection of the stimulation site and the selection of the stimulation mode.

Fig. 4A-B illustrate a method for initializing and updating a stimulation parameter table, such as tables 300 or 350. The table initialization and update method may be implemented in and performed by the controller circuit 250 as shown in fig. 2. As shown in the flow chart 410 in fig. 4A, table initialization begins at 411 where the patient physiological and physical conditions to be included in the table are received. The effect of the patient's condition on cardiac response and patient hemodynamics can be analyzed. In one example, changes in P-wave to R-wave interval (PRI), thoracic impedance, heart sound, or pulse wave transit time from their respective baseline measurements under a particular patient physiological or functional condition, such as measured from an ECG or intracardiac EGM, may be used to assess the impact of the patient condition. A patient condition that has an effect on the patient's hemodynamic response or cardiac response may be included in the stimulation parameter table.

At 412, a test protocol may be executed. The test protocol may include establishing various patient conditions, such as maintaining the patient in a particular posture, directing the patient's heart rate to a specified heart rate range (e.g., by atrial pacing or by controlled motion), or establishing other patient conditions. The PRI during atrial sensing AS or the AVI during atrial pacing AP may be measured. Measurement of PRI or AVI may include sensing ventricular response at one or more of an RV Sensing (RVs) site or an LV Sensing (LVs) site, such as using an RV sensing vector including an RV electrode (e.g., one of 152-154) or an LV sensing vector including an LV electrode (e.g., one of 161-164). The RV or LV sensing vector may be a unipolar sensing vector that includes the RV or LV sensing electrode as a cathode and the device container 112 as an anode. In one example, the PRI or AVI measured at 412 may include one or more of the following: AS-to-RVS intervals, AS-to-LVS intervals, AP-to-RVS intervals, and AP-to-LVS intervals. In some examples, the test protocol may include acquiring additional information such as patient echocardiographic measurements or other hemodynamic parameters or clinical diagnosis under various patient conditions.

At 413, one or more stimulation timing parameters (such as AVDs) may be calculated using the PRI or AVI measurements, or optionally along with other information acquired at 412. The PRI or combination of AVIs measured at the RV and LV can be used to calculate the sensed AVD and the paced AVD, respectively. In one example, the AVD is determined using a weighted combination, such as the following equation:

AVD＝k1*AV_R+k2*AV_L+k3 (1)

in equation (1), AV_RDenotes the interval between AS or AP to RVS, and AV_LIndicating the spacing between the AS or AP to the LVS. In one example, if the interventricular interval Δ LR between RV and LV is AV_L-AV_RLess than zero, then only AV may be used_LTo calculate the AVD, i.e. AVD k2 AV_L. In one example, k2 is approximately between 0.5 and 1And (3) removing the solvent. If Δ LR is equal to or greater than zero, AVD may be calculated as AV_RAnd AV_LAs given above in equation (1). The weighting factors k1 and k2 and the scalar offset k3 may be selected according to the synchronization of the LV and RV sensing. In one example, the weighting factors may be determined empirically using pacing data from a patient population, data obtained from echocardiographic studies, or other clinical diagnoses. In one example, weighting factors may be generated and used to calculate AVDs for different ventricular stimulation sites (LV or BiV only) or for different LV lead locations (e.g., anterior LV or free wall), respectively.

In some examples, the AVD computation may additionally include a beat screening process. A sufficient number (e.g., 3-20) of LVS or RVS beats meeting the sensing criteria during AS are needed to obtain a more reliable sensed AVD. Similarly, a sufficient number (e.g., 3-20) of LVS or RVS beats meeting the sensing criteria during AP are required to obtain a more reliable paced AVD. In one example, a median, average, or other central trend of a plurality of PRI or AVI measurements is used to determine the AVD, such as according to equation (1). In some examples, the sensed AVD may be used to determine a paced AVD if there are not enough LVS or RVS beats within a specified time or number of cardiac cycles. In one example, if Δ_LRGreater than zero milliseconds (msec), the sensed AVD may be determined to be approximately 60 msec longer than the sensed AVD. If Δ_LREqual to or less than zero milliseconds, the sensed AVD may be determined to be about 45 milliseconds longer than the sensed AVD.

The AVD so determined depends on either the RVS or LVS. In some examples, the RV or LV sensing electrode may be different from the RV or LV pacing electrode. Because the AVD is estimated using measurements from RV or LV sensing electrodes, at least due to the time offset (Δ) between cardiac activation at the sensing electrode site and the pacing electrode site_SP) The estimated AVD may not be optimal when applied to different RV or LV pacing electrodes to deliver pacing therapy. Referring to FIG. 1, by way of example and not limitation, sensing electrode LV 1161 is used to measure AV_L(AS or AP to LVS interval), while LV pacing is via inclusion of different chargesPole LV 3163 and LV pacing vectors of reservoir 112. Sensing pacing electrode time offset Δ between electrodes LV1 and LV3_SPMeasurements may be made under known patient conditions and applied to other patient conditions. By way of example and not limitation, Δ may be measured in relatively easily managed patient conditions, such as with Low Rate Limit (LRL) pacing when the patient is in a prone position_SP. Measured delta_SPMay be stored in memory circuit 240 for future use.

At 414, if the RV or LV sensing electrode is determined to be different from the RV or LV pacing electrode, then at 415, various patient conditions (including different from the Δ determined thereunder) are determined_SPEasily managed condition) can be determined by adding the sense-pace electrode time offset delta_SPAnd (6) carrying out correction. At 416, the corrected AVD may be added to the stimulation parameter table. If the same ventricular electrode is used for ventricular sensing and ventricular pacing at 414, then no AVD correction is needed; the AVD calculated at 413 may be added to the stimulation parameter table at 416. In some examples, the conditions under which the AVD is calculated (such AS HR range, patient posture, atrial activation pattern (e.g., AS or AP), or time of day AS shown in fig. 3A-3B) may be filtered against their respective interaction limits. For example, in certain patient conditions, the AVD may be determined when the pacing rate is limited by a lower Limit Rate (LRL) and/or a Maximum Tracking Rate (MTR). The interaction limits may be programmed into the system or device executing the test protocol. Such interaction limits for the patient condition may be advantageous for safe operation during performance of the test protocol in table initialization and during electrical stimulation therapy according to the AVD values in the table.

Fig. 4B is a flow chart 420 illustrating a method of updating a stimulation parameter table, such as a table created using method 410. The table may be updated periodically at a specified time (such as every minute, every few minutes, every hour, every day, every particular day, every week, every month, etc.). In some examples, the table update frequency may be determined using a table update history (such as a table update trend). The next table update may then be scheduled according to historical trends. For example, the next table update may be scheduled to not exceed the shortest update period (i.e., the time interval between two adjacent updates) within a time span (e.g., one year) in the patient history.

The updating of the stimulation parameter table may be performed for the entire table or a portion of the table, such as those table entries corresponding to one particular condition (e.g., stance). The frequency of table updates may vary for different portions of the table such that one portion of the table may be updated more frequently than another portion of the table. In one example, table entries corresponding to more frequently occurring conditions, such as a lower HR range (e.g., <100bpm), may be updated more frequently than table entries corresponding to less common or difficult to reach conditions, such as a higher HR range (e.g., >100 bpm).

Additionally or alternatively, table updates may be triggered by specific events. At 421, trigger events for table updates are monitored, including, for example, the amount (e.g., percentage) of pacing therapy patients received within a specified time period, worsening heart failure or decompensation events, hemodynamic response toward CRT, heart rate, posture, physical activity, heart sounds, the occurrence of intrinsic beats, sudden large changes in AVD recommendations, and so forth. In one example, the table update frequency may be determined based on variability of PRI or AVI in a given patient condition. In one example, the variance, standard deviation, range, or other extensional metric may be calculated from multiple PRIs or AVIs under a particular patient condition. A higher variability of PRI (such as when a specified threshold is exceeded) may indicate AV conduction irregularities and less efficient cardiac function in a particular patient condition. This may trigger the evaluation and updating of the stimulation parameter table.

If one or more trigger events occur and certain conditions are met (e.g., a threshold is exceeded or falls within a specified range of values) at 422, then at 423, the patient physiological or functional conditions can be evaluated to determine whether they continue to affect the patient's cardiac or hemodynamic response. Depending on the impact, existing conditions may be removed from the table or new conditions may be integrated into the table. At 424, the PRI during AS or AVI during AP may be re-measured under updated conditions, and the AVD may be determined, such AS using a similar method AS previously discussed with reference to fig. 4A, or along with other timing parameters.

Updating of table entries such as AVDs or other stimulation timing parameters requires sensing RV or LV activity (RVs or LVs, respectively) and measuring PRI or AVI. Conventionally, this may require at least temporary suspension of ventricular pacing therapy. This may be disadvantageous because even brief periods of inhibited pacing may lead to unfavorable patient prognosis. To ensure uninterrupted pacing during table updates, methods of dynamic PRI or AVI determination may be used, such as the method discussed below with reference to fig. 5. PRI or AVI may be estimated and the stimulation parameter table may be updated without the need to pause pacing therapy or otherwise compromise ongoing pacing therapy.

PRI/AVI determination at pacing

Fig. 5 illustrates a method 500 for dynamically determining PRI or AVI during pacing. The method 500 may be implemented in the system 200 and performed by the system 200. The dynamically determined PRI or AVI may be used to update a stimulation parameter table without suspending ventricular pacing therapy, switch between LV-only pacing and BiV pacing, switch between SSP and MSP, or other processes requiring estimation of PRI or AVI.

Method 500 includes a process 510 for estimating an offset (Δ) under controlled patient conditions, such as a known heart rate range and a known posture_I-PF). An offset Δ may be determined between the AVD and PRI or AVI corresponding to a pseudofusional beat_I-PF. A false fusion beat is an electrocardiographic manifestation of cardiac depolarization that results from the superposition of ineffective pacing stimuli on intrinsic cardiac depolarizations, such as spontaneous QRS complexes on an ECG or intrinsic ventricular beats on a ventricular EGM. Spurious fusion occurs when the intrinsic heart rate is very close to the pacing rate. A pacing stimulus, such as an RV pacing spike or LV pacing spike delivered according to AVD, is ineffective because it occurs temporally within the absolute refractory period of spontaneous QRS.

At 511, the AVD may be gradually adjusted, and ventricular pacing may be performed according to the adjusted AVD. In one example, the AVD may be initialized to a small value that is shorter than the PRI and gradually increased in specified steps (such as about 5-10 milliseconds).In another example, the AVD may start from a larger initial value, greater than the PRI, and gradually decrease in a specified step size. Ventricular pacing may be performed at each of the AVD values that are gradually adjusted. The evoked cardiac response to ventricular pacing may be monitored from ECG, intracardiac EGM, or physiologic sensor signals. In one example, the evoked cardiac response includes a morphology of cardiac electrical signals sensed by RV or LV sensing electrodes. In another example, the evoked cardiac response includes a morphology of a heart sound signal or a signal indicative of a mechanical response of the heart to pacing. Pseudofusion has a characteristic morphology in which pacing spikes are superimposed on the intrinsic QRS complex or intrinsic ventricular morphology. If the morphology indicates that false fusion has occurred at 513, the individualized offset Δ may be made from the superimposed waveform morphology_I-PFMeasured as AVD_PFAnd the interval between intrinsic PRI, i.e. Delta_I-PF＝PRI-AVD_PFWherein, AVD_PFAVDs that trigger spurious fusions are indicated. If no spurious fusion occurs at 513, the adjustment of the AVD may continue at 511. In some examples, the offset Δ_I-PFAnd may be in the range of between about 10-15 milliseconds. Offset delta_I-PFMay be stored in the memory circuit 240 for future use.

The process of dynamic PRI or AVI determination may begin at 520, where PRI estimation during pacing therapy (such as CRT or MSP) may be triggered periodically. Events that trigger PRI estimation may include stimulation parameter table updates, stimulation site updates (e.g., switching between LV-only pacing and BiV pacing), or stimulation mode updates (e.g., switching between SSP and MSP), among others. At 530, the AVD of the currently ongoing pacing therapy may be gradually increased, for example, at a specified step of approximately 5-10 milliseconds. Ventricular pacing morphology may be monitored with a gradually extending AVD during pacing. If a spurious fusion morphology is detected at 540, the AVD adjustment process may be terminated and the current AVD corresponding to the spurious fusion may be recorded_PF'. Note that AVD_PF' is measured under current patient conditions, which may be different from determining the AVD at 513_PFAnd Δ_I-PFThe condition of the patient. At 550, AVD may be used_PF' and stored offset Δ_I-PFTo estimate the estimated PRI, ePRI in the current patient condition:

ePRI＝AVD_PF'+Δ_I-PF(2)

assuming Δ according to (2) an estimation of PRI_I-PFSubstantially unaffected by changes in the patient's condition. Because the AVD expansion at 530 stops at the pseudo-fusion (at which point pacing therapy is still delivered) and never exceeds that point, pacing therapy can be effectively maintained during PRI determination. In addition, a prestored Δ is used_I-PFThe time for PRI or AVI calculation can be reduced, the battery power can be saved, and the calculation resources can be saved.

The estimated PRI or AVI may be used to update stimulation timing parameters, such as the AVD according to equation (1), or to re-evaluate and select stimulation sites between LV-only pacing and BiV pacing under various patient physiological or functional conditions, as will be discussed with reference to fig. 6. The inter-ventricular delay between the RV sensing site and one or more LV sensing sites may be derived from the estimated PRI or AVI. The inter-ventricular intervals may be used to assess stimulation pattern selection between SSP and MSP in various patient conditions, as discussed below with reference to fig. 7.

Dynamic stimulation site switching between LV-only pacing and BiV pacing

Fig. 6 shows an example of a method 600 for determining between LV-only pacing and BiV pacing. The method 600 may be implemented in and performed by a stimulation site selector circuit 231 as shown in fig. 2. In one example, the method 600 may be used to determine stimulation sites on a beat-by-beat basis (LV-only pacing or BiV pacing) or to adjust stimulation sites periodically at specified times.

The method 600 begins at 610, and a patient physiological or functional condition is identified at 610. During LV-only pacing or BiV pacing, patient conditions such as heart rate, patient posture, physical activity, atrial activation patterns, etc., may have an impact on hemodynamic outcomes. At 620, PRI or AVI is measured. The PRI may be measured from a surface ECG, and the AVI may be measured from an Atrial Sense (AS) or Atrial Pace (AP) event to a Right Ventricular Sense (RVS) event. In one example, PRI or AVI may be estimated while maintaining pacing therapy, such as using a method 500 based on pseudofusion detection. At 630, a trigger event is detected. The triggering event may include a change in a patient's physiological or functional condition, such as a change in posture, a change in physical activity intensity, or a chronic change in the patient's HF status (such as a decompensation event). In one example, the triggering event includes an increase in heart rate while the patient maintains a current physiological or physical condition. For example, if X beats out of Y beats exceed a heart rate threshold, stimulation site assessment may be triggered. In one example, three beats of five consecutive beats exceeding a frequency cutoff of 100 beats per minute (bpm) may trigger stimulation site assessment. Alternatively, at 630, stimulation site assessment may be performed periodically at a specified time.

If the heart rate criteria are met at 630, the measured PRI may be compared to a PRI threshold PRI at 640_THA comparison is made. In one example, PRI_THIn the range between about 250 and 270 milliseconds. In some examples, the threshold PRI may be determined empirically for various patient conditions, such as using echocardiographic data or other heart failure diagnosis_TH。PRI_THMay depend on the patient condition, such that PRI is in one patient condition_THPRI that can be compared to another different patient condition_THDifferent. In one example, PRI_THMay depend on the heart rate. PRI at a lower limit frequency (LRL) of a device may be adjusted_THSet to a first value, such as about 270 milliseconds. PRI at maximum tracking frequency (MTR) of device_THSet to a lower value, such as about 200 milliseconds. PRI at heart rate between LRL and MTR can be plotted using a linear, piecewise linear, exponential, or other non-linear curve_THInterpolation is between 200 ms and 270 ms. If the PRI exceeds a threshold PRI indicative of patient condition_THBiV pacing is recommended at 650.

If PRI does not exceed the threshold PRI_THThen the variability of the PRI may be evaluated at 660. Variability may be measured using variance, standard deviation, range, or other extensional metrics from multiple PRIs or AVIs in a given patient condition. If PRI variability exceeds patients at 660PRI variability threshold PRIVAr of condition indication_THBiV pacing is recommended at 650. A more variable PRI may indicate irregular AV conduction and deteriorated cardiac function, in which case BiV pacing may be superior to LV-only pacing in providing enhanced synchronized ventricular contraction and improved cardiac function. If the PRI is not substantially extended (e.g., falls below a threshold PRI)_THBelow) and less variability (e.g., down to the variability threshold PRIvar)_THBelow), then LV-only pacing may be recommended at 670.

Stimulation site selection or switching between LV-only pacing and BiV pacing may be performed on a beat-by-beat basis. Alternatively, to improve the reliability of the PRI and PRI variability measurements, PRI and PRI variability may be analyzed over multiple N beats, where N is a positive integer. In one example, N is between 10 and 20 beats. The N beats may be consecutive beats. Alternatively, the N beats may be non-consecutive. For example, a heartbeat is sensed every 5-15 seconds and PRI is calculated from that heartbeat, and N PRI can be calculated from N heartbeats. The decisions at 640 and 660 may show an extension (at 640) or increased variability (at 650) of the PRI based on at least M of the N heartbeats. In one example, M is equal to or greater than 50% of N. In another example, LV-only pacing or BiV pacing decisions may be evaluated over multiple beats of the N beats. If LV-only pacing is recommended for all N beats, then LV is recommended at 670. BiV pacing is recommended at 650 if BiV pacing is recommended for all N beats, or if LV-only pacing and BiV pacing are used mixed throughout the N beats.

Method 600 determines between LV-only pacing and BiV pacing based on AV conduction characteristics (including extended or increased variability of PRI or AVI). The method 600 may additionally use the sensed interventricular interval to determine a stimulation site. The interventricular interval represents the activation delay between the LV and RV and may be calculated AS the difference between (1) the AS-to-RVs interval and (2) the AS-to-LVs interval, or (1) the AP-to-RVs interval and (2) the AP-to-LVs interval. In one example, if the inter-ventricular interval is less than a threshold (e.g., 20 milliseconds), which may indicate the absence of left bundle branch block, BiV pacing is recommended at 650. If the interventricular interval is equal to or greater than the threshold (indicating that RV activation significantly lags LV activation, such as by more than 20 milliseconds), then the PRI and PRI variability criteria at 640 and 660 may be applied to determine between LV-only pacing and BiV pacing.

In some examples, information about LV lead location may be included in method 600 to determine a stimulation site. The lead location may be provided by the user or received by the patient condition receiver 220. In one example, even though PRI and PRI variability criteria at 640 and 660 recommend using BiV pacing, if the LV lead is in an anterior position, LV-only pacing is recommended instead.

Dynamic stimulation mode switching between SSP and MSP

Fig. 7 shows an example of a method 700 for determining between SSP pacing and MSP. The method 700 may be implemented in and performed by the stimulation mode selector circuit 232 as shown in fig. 2. In one example, the method 700 may be used to determine stimulation patterns (SSP or MSP) on a beat-by-beat basis, or to periodically adjust the stimulation site at specified times.

The method 700 begins at 710, and a patient physiological or functional condition is identified at 710. During SSP or MSP, patient conditions such as heart rate, patient posture, physical activity, atrial activation patterns, etc., may have an impact on hemodynamic outcomes. At 720, inter-ventricular intervals may be measured at a plurality of candidate LV sites { LV (i) }, respectively. The resulting interventricular separation { D (i) } represents the degree of dyssynchrony between the RV and the respective LV site { LV (i) }. In one example, RVS may be sensed using RV sensing vectors including one of RV electrodes 152-154, and LVS may be sensed at two or more LV sites using sensing vectors each including one of LV electrodes 161-164. The inter-ventricular interval may be calculated AS the difference between (1) the AS to RVS interval and (2) the AS to LVS interval. Alternatively, the inter-ventricular interval may be calculated as the difference between (1) the AP-to-RVS interval and (2) the AP-to-LVS interval. For example, for a particular LV site LV (j), the corresponding inter-ventricular interval d (j) ═ AV_R–AV_L(j) Wherein, AV_RRepresents a delay between the AS or AP and the RVS, and AV_L(j) Representing the delay between AS or AP and the LVs sensed at the jth LV site LV (j). In one example, AV can be measured while maintaining pacing therapy, such as using a method 500 based on pseudofusion detection_ROr AV_L。

At 730, a trigger event is detected. The triggering event may include a change in a patient's physiological or functional condition, such as a change in posture, a change in physical activity intensity, or a chronic change in the patient's HF status (such as a decompensation event). In one example, the triggering event includes an increase in heart rate. Stimulation site assessment may be triggered if X out of Y beats exceed a heart rate threshold. In one example, three beats out of five consecutive beats of a frequency cutoff of over 100bpm may trigger stimulation pattern assessment. Alternatively, stimulation pattern evaluation may be performed periodically at specified times.

If the heart rate criteria are met at 730, then a stimulation pattern evaluation is triggered at 740, and the interventricular interval { D (i) } corresponding to the LV site { LV (i) } may be respectively compared to an interventricular delay threshold D_THA comparison is made. In one example, the threshold D may be determined for various patient conditions, such as using echocardiographic data or other heart failure diagnosis_TH. Threshold value D_THMay depend on the patient condition such that the threshold D is at one patient condition_THPRI that can be compared to another different patient condition_THDifferent. If the corresponding inter-ventricular interval D (i) exceeds a threshold D_THAn LV site such as LV (i) may be selected to deliver pacing. For example, because of the threshold value D_THDepending on the patient indication, the LV area LV (i) may be selected for the prone position, while a different LV area LV (j) may be selected for the standing position. If two or more LV sites meet the interventricular interval criteria at 740, LV electrodes at those LV sites are selected to deliver MSP at 760. If only one LV site meets the interventricular spacing criteria, then SSP using the LV electrode at that site is recommended at 750. If none of the LV sites meets the interventricular spacing criteria, then it is recommended at 750 to use the longest of the candidate LV sites { LV (i) }The interventricular interval of (a) corresponds to the SSP of the LV electrode.

Non-transitory machine-readable medium

Fig. 8 illustrates a block diagram of an example machine 800 on which any one or more of the techniques (e.g., methods) discussed herein may be executed. Portions of this description may be applicable to the computing framework of various portions of an LCP device, IMD, or external programmer.

In alternative embodiments, the machine 800 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine 800 may operate in the capacity of a server machine, a client machine, or both, in server-client network environments. In one example, the machine 800 may operate as a peer machine in a peer-to-peer (P2P) (or other distributed) network environment. The machine 800 may be a Personal Computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a mobile telephone, a web appliance, a network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term "machine" shall also be taken to include any collection of machines that individually or jointly execute one or more sets of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), other computer cluster configurations.

As described herein, an example may include, or be operated by, logic or multiple components or mechanisms. A circuit group is a collection of circuits implemented in a tangible entity that includes hardware (e.g., simple circuits, gates, logic, etc.). Circuit group components can be flexible over time and underlying hardware variability. The circuit group includes members that can perform specified operations upon operation, individually or in combination. In one example, the hardware of the circuit group may be designed to perform certain operations (e.g., hard-wired) without change. In one example, the hardware of the circuit set may include variably connected physical components (e.g., execution units, transistors, simple circuits, etc.) that include a computer-readable medium physically modified (e.g., magnetically, electrically, movably placing a constant mass of particles, etc.) to encode instructions for a particular operation. In connecting physical components, the basic electrical characteristics of the hardware components are changed, for example, from an insulator to a conductor or vice versa. These instructions enable embedded hardware (e.g., an execution unit or loading mechanism) to create components of a circuit group in the hardware via a variable connection to perform portions of a particular operation when operating. Thus, when the device is operating, the computer readable medium is communicatively coupled to the other components of the circuit group member. In one example, any physical assembly may be used in more than one component of more than one circuit group. For example, in operation, the execution unit may be used in a first circuit group at one point in time and reused by a second circuit in the first circuit group at a different time or reused by a third circuit in the second circuit group.

The machine (e.g., computer system) 800 may include a hardware processor 802 (e.g., a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), a hardware processor core, or any combination thereof), a main memory 804 and a static memory 806, some or all of which may communicate with each other via an interconnection link (e.g., bus) 808. The machine 800 may also include a display unit 810 (e.g., a raster display, a vector display, a holographic display, etc.), an alphanumeric input device 812 (e.g., a keyboard), and a User Interface (UI) navigation device 814 (e.g., a mouse). In one example, the display unit 810, the input device 812, and the UI navigation device 814 may be a touch screen display. The machine 800 may additionally include a storage device (e.g., drive unit) 816, a signal generation device 818 (e.g., a speaker), a network interface device 820, and one or more sensors 821 such as a Global Positioning System (GPS) sensor, compass, accelerometer, or other sensor. The machine 800 may include an output controller 828, such as a serial (e.g., Universal Serial Bus (USB)), parallel, or other wired or wireless (e.g., Infrared (IR), Near Field Communication (NFC), etc.) connection to communicate with or control one or more peripheral devices (e.g., a printer, card reader, etc.).

The storage device 816 may include a machine-readable medium 822 on which is stored one or more sets of data structures and instructions 824 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 824 may also reside, completely or at least partially, within the main memory 804, within static memory 806, or within the hardware processor 802 during execution thereof by the machine 800. In one example, one or any combination of the hardware processor 802, the main memory 804, the static memory 806, or the storage device 816 may constitute machine-readable media.

While the machine-readable medium 822 is shown to be a single medium, the term "machine-readable medium" can include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 824.

The term "machine-readable medium" may include any medium that is capable of storing, encoding or carrying instructions for execution by the machine 800 and that cause the machine 800 to perform any one or more of the techniques of this disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting examples of machine-readable media may include solid-state memory, as well as optical and magnetic media. In one example, a high capacity machine readable medium includes a machine readable medium having a plurality of particles with an invariant (e.g., static) mass. Thus, a mass machine-readable medium is not a transitory propagating signal. Specific examples of the mass machine-readable medium 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.

Any of a number of transmission protocols (e.g., frame relay, Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), hypertext transfer protocol (HTTP), etc.) may also be utilized in the communication network826 the instructions 824 are transmitted or received via the network interface device 820 using a transmission medium. Example communication networks may include a Local Area Network (LAN), a Wide Area Network (WAN), a packet data network (e.g., the internet), a mobile telephone network (e.g., a cellular network), a Plain Old Telephone (POTS) network, and a wireless data network (e.g., referred to as a "POTS") networkOf the Institute of Electrical and Electronics Engineers (IEEE)802.11 family of standards, referred to as

IEEE 802.16 family of standards), IEEE 802.15.4 family of standards), peer-to-peer (P2P) networks, and the like. In one example, the network interface device 820 may include one or more physical jacks (e.g., ethernet, coaxial, or telephone jacks) or one or more antennas to connect to the communication network 826. In one example, the network interface device 820 may include multiple antennas to wirelessly communicate 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" shall be taken to include any intangible medium that is capable of storing, encoding or carrying instructions for execution by the machine 800 and that includes digital or analog communications signals, or other intangible medium to facilitate communication of such software.

Various embodiments are shown in the above figures. One or more features from one or more of these embodiments may be combined to form further embodiments.

The method examples described herein may be at least partially machine-implemented or computer-implemented. Some examples may include a computer-readable medium or machine-readable medium encoded with operational instructions to configure an electronic device or system to perform the methods described in the examples above. Implementations of such methods may include code, such as microcode, assembly language code, a high-level language code, and so forth. Such code may include computer readable instructions for performing various methods. The code may form part of a computer program product. Further, the code may be tangibly stored on one or more volatile or non-volatile computer-readable media during execution or at other times.

The foregoing detailed description is intended to be illustrative rather than limiting. The scope of the disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.