Posture-based sensing and medical therapy delivery system

Abstract

An implantable medical device (IMD) comprising: one or more medical therapy delivery elements; one or more sensors; memory; and processing circuitry. The processing circuitry is configured to: receive sensed signals from the one or more sensors; determine, based on the received sensed signals, a posture of the patient; retrieve one or more therapy delivery parameter values stored in the memory, wherein the one or more therapy delivery parameter values correspond to the determined posture; determine that the one or more therapy delivery parameter values for the determined posture were configured within a threshold period of time from a current time; and in response to determining that the one or more therapy delivery parameter values were configured within the threshold period of time, cause the one or more medical therapy delivery elements to deliver medical therapy to the patient based on the one or more therapy delivery parameter values.

Description

POSTURE-BASED SENSING AND MEDICAL THERAPY DELIVERY SYSTEM

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 600,905, filed November 20, 2023, the entire content of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The present application relates to medical devices, including implantable medical devices (IMDs), configured to sense electrical signals from and / or deliver medical therapy to a patient.BACKGROUND

[0003] Medical devices are implanted, partially implanted and / or worn on a body of a patient to sense physiological signals and / or deliver therapy to a patient. In some instances, a medical device system includes one or more IMDs implanted within a body of a patient. The one or more IMDs may sense signals from and / or deliver medical therapy to a target tissue of the patient via sensing element(s) and / or therapy delivery element(s), respectively. The sensing element(s) and / or therapy delivery element(s) may not be directly coupled to the target tissue. Instead, there may be intervening tissue between the target tissue and the sensing element(s) and / or therapy delivery element(s), through which the sensing element(s) and / or therapy delivery element(s) may sense signals from and / or deliver medical therapy to the target tissue through tissue.SUMMARY

[0004] When a patient moves about in an ambulatory setting or in the course of normal daily activities, the patient may assume different postures (e.g., standing, sitting, supine, bending, crouching, leaning on side, leaning forward, leaning backwards, etc.) and may transition between different postures. When the patient is in different postures, the targeted site of the patient for sensing and / or therapy delivery (e.g., the heart) may be a different distance from one or more elements of a medical device system, such as an implantable medical device (IMD) system, and / or may move in different directions (e.g., during the cardiac cycle, or the respiration cycle) relative to one or more electrodes of theIMD or lead coupled to the IMD. The different distances and / or orientations of the target site and the one or more electrodes may impede the sensing of desired physiological signals and / or the delivery of stimulation therapy by the IMD of the IMD system.

[0005] In one example, the target site may be the heart and the IMD system may include an implantable cardiac device (e.g., implantable cardioverter-defibrillator (ICD), pacemaker, cardiac resynchronization therapy (CRT) device, or insertable cardiac monitor (ICM)) that includes or is coupled to one more electrodes for sensing cardiac signals and / or delivery cardiac stimulation therapy (e.g., bradycardia pacing, anti-tachycardia pacing (ATP), CRT, cardioversion or defibrillation shocks or the like). When the patient is in different postures, the different distances between the one or more electrodes and the heart may lead to oversensing or under- sensing of the cardiac signals when the IMD performs the sensing of the cardiac signals based on a same set of sensing parameter values. In some examples, when the patient is in different postures, the different distances between the one or more electrodes and the heart may lead to delivery by the IMD of cardiac pacing therapy insufficient to capture cardiac tissue or in excess of a capture threshold of the cardiac tissue. Delivery of cardiac pacing therapy in excess of the capture threshold to the patient may lead to increased patient discomfort and / or increased power consumption, which may decrease an overall lifespan of the IMD and acceptance of the pacing therapy.

[0006] This disclosure describes devices, systems, and methods for adjusting sensing parameter values and / or therapy delivery parameter values based on a posture of the patient. In some examples, the IMD may adjust, based on the posture of the patient, sensing parameter values to increase and / or decrease sensing sensitivity of sensing circuitry of the IMD. In some examples, the IMD may adjust, based on the posture of the patient, therapy delivery parameter values and deliver medical therapy based on the updated therapy delivery parameter values. While this disclosure primarily describes systems and devices configured to sense cardiac signals and deliver cardiac therapy to a heart of a patient, the example devices, systems, and methods described herein may be performed by other IMDs configured to sense other signals from the patient and / or deliver other medical therapy to the patient. For example, the example devices, systems, and methods described herein may be applicable to other instances where distance and / or orientation between one or more elements of an IMD (e.g., a sensing element and / or atherapy delivery element) and a target location of the patient change in response to shifts in posture by the patient.

[0007] In some examples, the IMD system may be an extravascular implantable cardioverter defibrillator (EV ICD) system including one or more ICDs. The one or more ICDs may sense cardiac signals from and / or deliver cardiac pacing therapy to cardiac tissue of the patient. The one or more ICDs may not be directly coupled to the cardiac tissue and may sense signals from and / or deliver cardiac pacing to the cardiac tissue through intervening tissue between the cardiac tissue and the one or more ICDs. The one or more ICDs may adjust sensing parameters based on patient posture to accurately sense cardiac signals. The one or more ICDs may adjust therapy delivery parameters (e.g., pacing parameters) based on patient posture to capture the cardiac tissue via the cardiac pacing without unnecessary power consumption and / or patient discomfort.

[0008] The example devices, systems, and methods described herein may provide several advantages over other IMDs systems. Adjusting sensing parameter values based on the posture of the patient may reduce occurrences of oversensing and / or under-sensing by the IMD, which may increase an accuracy of determinations by the IMD based on the sensed signals and / or increase efficacy of a medical therapy delivered by the IMD based at least in part on the sensed signals. Adjusting therapy delivery parameter values based on the posture of the patient may increase efficacy of the medical therapy (e.g., by ensuring that the medical therapy captures cardiac tissue of the patient), may increase the overall lifespan of the IMD (e.g., by reducing unnecessary consumption of energy during medical therapy delivery), and / or may decrease patient discomfort resulting from the delivery of medical therapy (e.g., by reducing instances of the delivery of excessive medical therapy to the patient).

[0009] In some examples, this disclosure describes an implantable medical device (IMD) configured to be implanted in a patient, the IMD comprising: one or more medical therapy delivery elements; one or more sensors; memory; and processing circuitry configured to: receive sensed signals from the one or more sensors; determine, based on the received sensed signals, a posture of the patient; retrieve one or more therapy delivery parameter values stored in the memory, wherein the one or more therapy delivery parameter values correspond to the determined posture; determine that the one or more therapy delivery parameter values for the determined posture were configured within athreshold period of time from a current time; and in response to determining that the one or more therapy delivery parameter values were configured within the threshold period of time, cause the one or more medical therapy delivery elements to deliver medical therapy to the patient based on the one or more therapy delivery parameter values.

[0010] In some examples, this disclosure describes a method comprising: receiving, by processing circuitry of an implantable medical device (IMD) implanted within a patient and from one or more sensors of the IMD, sensed signals; determining, by the processing circuitry and based on the received sensed signals, a posture of the patient; retrieving, by the processing circuitry and from memory of the IMD, one or more therapy delivery parameter values corresponding to the determined posture; determining, by the processing circuitry, that the one or more therapy delivery parameter values were configured within a threshold period of time from a current time; and in response to determining that the one or more therapy delivery parameter values were configured within the threshold period of time, causing, by the processing circuitry, one or more medical therapy delivery elements of the IMD to deliver medical therapy to the patient based on the one or more therapy delivery parameter values.

[0011] In some examples, this disclosure describes an implantable medical device (IMD) configured to be implanted in a patient, the IMD comprising: sensing circuitry coupled to one or more electrodes; therapy delivery circuitry coupled to the one or more electrodes; one or more sensors; memory; and processing circuitry configured to: receive sensed signals from the one or more sensors; determine, based on the received sensed signals, a posture of the patient; retrieve, from the memory, one or more sensing parameter values for one or more sensing parameters, the one or more sensing parameter values corresponding to the determined posture; cause the sensing circuitry to sense electrical signals from the patient via the one or more electrodes based on the one or more retrieved sensing parameter values; in response to a determination that the sensed electrical signals satisfy a threshold condition, deliver cardiac pacing therapy to the patient, wherein to deliver the cardiac pacing therapy, the processing circuitry is configured to: retrieve one or more pacing parameter values stored in the memory, wherein the one or more pacing parameter values correspond to the determined posture; determine that the one or more pacing parameter values for the determined posture were configured within a threshold period of time from a current time; and in response to determining that the one or morepacing parameter values were configured within the threshold period of time, control the therapy delivery circuitry to deliver the cardiac pacing therapy to the patient via the one or more electrodes based on the one or more pacing parameter values.

[0012] In some examples, this disclosure describes an implantable medical device (IMD) configured to be implanted in a patient, the IMD comprising: a sensing element coupled to tissue of the patient; one or more sensors; memory; and processing circuitry configured to: receive sensed signals from the one or more sensors; determine, based on the received sensed signals, a posture of the patient; and in response to the determined posture, cause the sensing element to sense electrical signals from the tissue based on one or more sensing parameter values stored in the memory, wherein the one or more sensing parameter values correspond to the determined posture.

[0013] This summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the systems, devices, and methods described in detail within the accompanying drawings and description below. Further details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the statements provided below.BRIEF DESCRIPTION OF DRAWINGS

[0014] Reference is made to the attached drawings, wherein elements have the same reference numeral designations represent similar elements throughout.

[0015] FIG. 1 is a conceptual diagram illustrating a front view of a patient with an example implantable medical device (IMD) system implanted extravascularly.

[0016] FIG. 2 is a conceptual diagram illustrating a side view of the patient with the example IMD system of FIG. 1.

[0017] FIG. 3 is a functional block diagram illustrating an example configuration of the components of the example IMD system of FIG. 1.

[0018] FIG. 4 is a flow chart illustrating an example process of adjusting sensing parameter values of an example IMD system based on changes in patient posture.

[0019] FIG. 5 is a flow chart illustrating an example process of adjusting pacing parameter values of an example IMD system based on changes in patient posture.

[0020] FIG. 6 is a flow chart illustrating an example process of adjusting sensing parameter values and pacing parameter values of an example IMD system based on changes in patient posture.DETAILED DESCRIPTION

[0021] An IMD of an IMD system may be implanted within a patient. The IMD may sense signals from tissue of the patient and / or may deliver medical therapy to tissue at a target location within the patient. In some examples, the IMD system may be an extravascular implantable cardioverter defibrillator (EV ICD) system, which includes one or more IMD (e.g., an ICD) implanted within the patient. The IMD system may deliver medical therapy (e.g., cardiac pacing therapy) from one or more electrodes coupled to the IMD, through tissue of the patient, and to cardiac tissue of the patient. If sensing element(s) and / or therapy delivery element(s) (e.g., electrode(s)) of the IMD system are not directly coupled to the target tissue (e.g., to cardiac tissue of the patient), the distance between the sensing element(s) and / or the therapy delivery element(s) and the target tissue may vary based on the posture of the patient. For example, when the patient is standing, sitting, supine, or in another posture, the distance between the sensing element(s) and / or the therapy delivery element(s) and the target tissue may be different.

[0022] In such examples, when sensing element(s) sense signals from the target tissue based on the same sensing parameter values, sensing element(s) may over-sense or undersense the signals when the patient is in different postures due to the different distances between sensing element(s) and the target tissue. In some examples, when therapy delivery element(s) deliver medical therapy to the target tissue based on the same therapy delivery parameter values, the medical therapy may be insufficient to achieve a threshold efficacy or may be excessive relative to the threshold efficacy when the patient is in different postures due to the different distances between therapy delivery element(s) and the target tissue. For example, when the IMD delivers cardiac therapy to the patient, a same magnitude, e.g., pulse amplitude and / or pulse width, may be insufficient to capture cardiac tissue when the patient is in a first posture and may be greater than a capture threshold of the cardiac tissue when the patient is in a second posture. In such examples, delivering cardiac therapy with pulse amplitudes and / or pulse widths in excess of the capture threshold may unnecessarily expend power and / or may lead to increased patientdiscomfort for some device configurations, such as, but is not limited to, an like, extravascular ICD.

[0023] The devices, systems, and methods described herein may adjust sensing parameter values and / or therapy delivery parameter values based on the posture of the patient. In some examples, the IMD may adjust sensing parameter values based on the posture of the patient to increase or decrease a sensing sensitivity of the IMD. For example, the IMD may increase sensing sensitivity when the patient is in a posture where the target tissue and the sensing element(s) are separated by a greater distance, or vice versa. In some examples, the IMD may adjust therapy delivery parameter values based on patient posture to control efficacy of the medical therapy delivered by the IMD. For example, the IMD may reduce a magnitude and / or pulse width and / or a frequency of the medical therapy when the patient is in a posture where the target tissue and the therapy delivery element(s) are closer together to inhibit unintended delivery of excessive medical therapy (e.g., medical therapy with a magnitude and / or frequency in excess of a minimum magnitude and / or frequency required to successfully treat the patient). In some examples, the IMD may increase a magnitude and / or pulse width and / or a frequency of the medical therapy when the patient is in a posture where the target tissue and the therapy delivery element(s) are further apart to ensure that the delivered medical therapy is efficacious. In some examples, where the IMD senses signals along sensing vector(s) and / or deliver medical therapy along therapy delivery vector(s), the IMD may adjust one or more vectors based on the patient posture.

[0024] Adjusting, by the IMD, sensing parameter values and / or therapy delivery parameter values based on patient posture may provide several advantages over other IMDs or IMD systems. For example, IMD may adjust sensing parameter values based on patient posture, which may reduce sensing sensitivity when sensing element(s) are closer to the target tissue or vice versa. Adjusting sensing sensitivity in response to the distance between sensing element(s) and the target tissue may inhibit and / or reduce oversensing or under-sensing of signals by the IMD. In some examples, the IMD may adjust therapy delivery parameter values based on patient posture, which may control the magnitude and / or frequency of the medical therapy such that when the IMD delivers the medical therapy, the medical therapy provides efficacious, therapeutic effects on the target tissue without unnecessary consumption of power or another resource, or patient discomfort.

[0025] While the example devices, systems, and methods in this disclosure are described primarily with reference to an ICD configured to sense electrical signals from and / or deliver electrical energy to a heart of a patient, the example IMDs, IMD systems, and / or methods may sense signals from and / or deliver medical therapy to another target tissue in the patient. The target tissue may include, but are not limited to, another organ of the patient, a nerve of the patient, or tissue adjacent a body lumen of the patient.

[0026] As used herein, relational terms, such as “first” and “second,” “over” and “under,” “front” and “rear,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements.

[0027] FIG. 1 is a conceptual diagram illustrating a front view of a patient 102 with an example implantable medical device (IMD) system 100 implanted intra-thoracically or extravascularly. FIG. 2 is a conceptual diagram illustrating a side view of patient 102 with example IMD system 100 of FIG. 1. IMD system 100 (also referred to herein as “system 100”), may be, but is not limited to, an ICD system or an EV ICD system. System 100 may include IMD 106 connected to an implantable medical lead 108. IMD may include, but is not limited to, an ICD.

[0028] ICD 106 may include a housing that forms a hermetic seal that protects components of the ICD 106. The housing of ICD 106 may be formed of a conductive material, such as titanium or titanium alloy, which may function as a housing electrode (sometimes referred to as a can electrode). In some embodiments, ICD 106 may be formed to have or may include a plurality of electrodes on the housing. ICD 106 may also include a connector assembly (also referred to as a connector block or header) that includes electrical feedthroughs through which electrical connections are made between conductors of lead 108 and electronic components included within the housing of ICD 106. As will be described in further detail herein, the housing may house one or more processors, memories, transmitters, receivers, sensors, sensing circuitry, therapy circuitry, power sources and other appropriate components. The housing is configured to be implanted in a patient, such as patient 102.

[0029] ICD 106 may be implanted extra-thoracically on the left side of patient 102, e.g., under the skin and outside the ribcage (subcutaneously or submuscularly). ICD 106 may, in some instances, be implanted between the left posterior axillary line and the leftanterior axillary line of patient 102. Lead 108 may include an elongated lead body 110 having a distal portion 110A sized to be implanted in an extracardiovascular location proximate heart 104, e.g., extravascularly, as illustrated in FIGS. 1 and 2, or extra- thoracically. For example, lead 108 may extend extra-thoracically under the skin and outside the ribcage (e.g., subcutaneously or submuscularly) from ICD 106 toward the center of the torso of patient 102, for example, toward the xiphoid process 116 of patient 102. At a position proximate xiphoid process 116, the lead body 110 may bend or otherwise turn and extend superiorly. The bend may be pre-formed and / or lead body 110 may be flexible to facilitate bending. In the example illustrated in FIGS. 1 and 2, the lead body 110 extends superiorly extravascularly underneath sternum 112, in a direction substantially parallel to sternum 112.

[0030] Distal portion 110A of lead 108 may reside in a substemal location such that distal portion 110A of lead 108 extends superior along the posterior side of sternum 112 substantially within the anterior mediastinum. The anterior mediastinum may be viewed as being bounded laterally by pleurae, posteriorly by pericardium, and anteriorly by sternum 112. In some instances, the anterior wall of the anterior mediastinum may also be formed by the transversus thoracis and one or more costal cartilages. The anterior mediastinum includes a quantity of loose connective tissue (such as areolar tissue), adipose tissue, some lymph vessels, lymph glands, substernal musculature (e.g., transverse thoracic muscle), the thymus gland, branches of the internal thoracic artery, and the internal thoracic vein (ITV).

[0031] Lead body 110 may extend superiorly extra-thoracically (instead of intra- thoracically), e.g., either subcutaneously or submuscularly above the ribcage / sternum 112. Lead 108 may be implanted at other locations, such as over sternum 112, offset to the right of sternum 112, angled lateral from the proximal or distal end of sternum 112, or the like. In some examples, lead 108 may be implanted within an extracardiac vessel within the thorax, such as the ITV, the intercostal veins, the superior epigastric vein, or the azygos, hemiazygos, and accessory hemiazygos veins. In some examples, distal portion 110A of lead 108 may be oriented differently than is illustrated in FIGS. 1 and 2, such as orthogonal or otherwise transverse to sternum 112 and / or inferior to heart 104. In such examples, distal portion 110A of lead 108 may be at least partially within the anteriormediastinum. In some examples, distal portion 110A of lead 108 may be placed between heart 104 and lung as well as within the pleural cavity.

[0032] Lead body 110 may have a generally tubular or cylindrical shape and may define a diameter of approximately 3-9 French (Fr). However, lead bodies of less than 3 Fr or more than 9 Fr may also be utilized. In another configuration, lead body 110 may have a flat, ribbon, or paddle shape with solid, woven filament, or metal mesh structure, along at least a portion of the length of the lead body 110. In such an example, the width across lead body 110 may be between 1-3.5 millimeters (mm). Other lead body designs may be used without departing from the scope of this application.

[0033] Lead body 110 may be formed from a non-conductive material, including silicone, polyurethane, fluoropolymers, mixtures thereof, and other appropriate materials, and shaped to form one or more lumens (not shown), however, the techniques are not limited to such constructions. Distal portion 110A may be fabricated to be biased in a desired configuration, or alternatively, may be manipulated by the clinician into the desired configuration. For example, distal portion 110A may be composed of a malleable material such that the clinician can manipulate distal portion 110A into a desired configuration where it remains until manipulated to a different configuration.

[0034] Lead body 110 may include a proximal portion HOB and distal portion 110A which include sensing / therapy elements 114 (e.g., electrodes 114) configured to deliver medical therapy (e.g., electrical energy) to heart 104 or sense electrical signals of heart 104. In some examples, sensing / therapy elements 114 may deliver medical therapy to another target tissue of patient 102 instead of or in addition to heart 104. Distal portion 110A may be anchored to a desired position within patient 102, for example, substernally or subcutaneously by, for example, suturing distal portion 110A to musculature, tissue, or bone of patient 102 at the xiphoid process entry site. In some examples, distal portion 110A may be anchored to patient 102 or through the use of rigid tines, prongs, barbs, clips, screws, and / or other projecting elements or flanges, disks, pliant tines, flaps, porous structures such as a mesh-like elements and metallic or non-metallic scaffolds that facilitate tissue growth for engagement, bio-adhesive surfaces, and / or any other nonpiercing elements.

[0035] Distal portion 110A includes one or more sensing / therapy elements 114. Each element 114 may be a therapy delivery element and / or a sensing element. Eachsensing / therapy element 114 may deliver a medical therapy to target tissue of patient 102. The medical therapy may include, but are not limited to, a chemical substance or an energy (e.g., thermal energy, cryogenic energy, electrical energy). In some examples, one or more of sensing / therapy elements 114 may sense signals (e.g., electrical signals) from patient 102 in addition to delivering the medical therapy, sensing / therapy elements 114 may include one or more electrodes. The electrodes may be configured to deliver cardiac pacing therapy and / or an anti-tachy arrhythmia, e.g., cardioversion / defibrillation, shock to heart 104 of patient 102. In some examples, distal portion 110A includes a plurality of pacing, sensing, or defibrillation electrodes spaced a distance apart from each other along the length of distal portion 110A. In some examples, as illustrated in FIG. 1, distal portion 110A includes two sensing / therapy elements 114. In other examples, distal portion 110A may include one or three or more sensing / therapy elements 114.

[0036] Sensing / therapy elements 114 may be disposed around or within lead body 110 of distal portion 110A, or alternatively, may be embedded within the wall of lead body 110. In one configuration, sensing / therapy elements 114 may be coil electrodes formed by a conductor. The conductor may be formed of one or more conductive polymers, ceramics, metal-polymer composites, semiconductors, metals or metal alloys, including but not limited to, one of a combination of the platinum, tantalum, titanium, niobium, zirconium, ruthenium, indium, gold, palladium, iron, zinc, silver, nickel, aluminum, molybdenum, stainless steel, MP35N, carbon, copper, polyaniline, polypyrrole, and other polymers. In another configuration, each of sensing / therapy elements 114 may be a flat ribbon electrode, a paddle electrode, a braided or woven electrode, a mesh electrode, a directional electrode, a patch electrode, or another type of electrode configured to sense electrical signals from and / or deliver electrical signals to heart 104 of patient 102.

[0037] In some examples, one or more electrodes (e.g., of sensing / therapy elements 114 and / or sensing elements of IMD 106) may be configured to deliver low-voltage (e.g., relative to other therapies such as anti-tachyarrhythmia shocks) electrical pulses to heart 104 and / or may sense a cardiac electrical activity, e.g., depolarization and repolarization of heart 104. Electrodes may be electrically isolated from an adjacent electrode by an electrically insulating material. Each electrode may have its own separate conductor along lead body 110 such that a voltage may be applied to or sensed via each electrode independently from another electrode.

[0038] Proximal portion HOB of lead body 110 may include one or more connectors to electrically couple lead 108 to IMD 106. IMD 106 may also include a connector assembly that includes electrical feedthroughs through which electrical connections are made between the one or more connectors of lead 108 and the electronic components included within the housing. The housing of IMD 106 may house one or more processors, memories, transmitters, receivers, sensors, sensing circuitry, therapy circuitry, power sources (e.g., capacitors and batteries), and / or other components. The components of IMD 106 may generate and deliver electrical therapy such as anti-tachycardia pacing, cardioversion or defibrillation shocks, post-shock pacing, and / or bradycardia pacing.

[0039] IMD 106 may sense signals from heart 104 via sensing elements and / or sensing / therapy elements 114 based on one or more sensing parameters. The one or more sensing parameters may include, but are not limited to, sensing thresholds, threshold timings, sensing sensitivity, or sensing vectors. Sensing vectors may indicate which elements of a plurality of sensing elements and / or sensing / therapy elements 114 IMD 106 selects to sense signals. IMD 106 may deliver medical therapy (e.g., cardiac pacing signals) to a target tissue (e.g., to heart 104) via sensing / therapy elements 114 based on one or more therapy delivery parameters. The one or more therapy delivery parameters may include, but are not limited to, therapy magnitude, therapy frequency, therapy duration, or therapy delivery vectors. Therapy delivery vectors may indicate which elements of a plurality of sensing / therapy elements 114 IMD 106 selects to deliver medical therapy. In some examples, where IMD 106 is configured to deliver cardiac pacing to heart 104, the therapy delivery parameters include pacing parameters. Pacing parameters may include, but are not limited to, pacing amplitude, pacing pulse width, pacing frequency, or pacing vectors.

[0040] Sensing / therapy elements 114 on lead body 110 may not be directly coupled to heart 104. As patient 102 shifts in posture, a distance between each of sensing / therapy elements 114 and heart 104 may change accordingly. For example, a distance between sensing / therapy elements 114 and heart 104 may be greater when patient 102 is supine compared to when patient 102 is crouched. IMD 106 may adjust sensing parameter values based on the posture of patient 102 to account for the distance between sensing / therapy elements 114 and heart 104 and prevent oversensing or under- sensing of signals from heart 104. IMD 106 may adjust therapy delivery parameter values (e.g., pacing parametervalues) to account for the distance between sensing / therapy elements 114 and heart 104 and ensure adequate capture of cardiac tissue of heart 104. IMD 106 may adjust the pacing parameter values to deliver cardiac pacing with a minimum pacing amplitude, pacing pulse width, and / or pacing frequency required to capture cardiac tissue when patient 102 is in the posture, e.g., to reduce power expenditure for delivering the cardiac pacing and / or reduce patient discomfort from the delivery of the cardiac pacing.

[0041] FIG. 3 is a functional block diagram illustrating an example configuration of the components of the example IMD system 100 of FIG. 1. As illustrated in FIG. 3, IMD 106 includes sensor(s) 202, sensing circuitry 204, therapy delivery circuitry 206, processing circuitry 208, communication circuitry 210, memory 212, and power source 214. In some examples, IMD 106 may include more or fewer components. The described circuitry and other components may be implemented together on a common hardware component or separately as discrete but interoperable hardware or software components. Depiction of different features is intended to highlight different functional aspects and does not necessarily imply that such circuitry and other components must be realized by separate hardware or software components. Rather, functionality associated with one or more circuitries and components may be performed by separate hardware or software components or integrated within common or separate hardware or software components.

[0042] Sensor(s) 202 may include one or more components configured to sense an orientation of IMD 106. The one or more components may include, but are not limited to, accelerometer(s) 203, gyroscopes, or inertial measurement units (IMUs). Accelerometer(s) 203 may include 3-axis accelerometer(s). Sensor(s) 202 may sense signals corresponding to an orientation of IMD 106. Sensor(s) 202 may transmit sensed signals corresponding to the orientation of IMD 106 to processing circuitry 208. When patient 102 is in different postures, the orientation of IMD 106 within patient 102 may be different. Therefore, the orientation of IMD 106 may correspond to the posture of patient 102 and IMD 106 may determine changes in posture of patient 102 based at least in part on detected changes in orientation of IMD 106 by sensor(s) 202.

[0043] Sensor(s) 202 may be disposed within the housing of IMD 106 or may be disposed outside of the housing of IMD 106. Sensor(s) 202 may be disposed in implantable devices separate from and in communication with IMD 106. In some examples, sensor(s) 202 may be disposed within an external device worn by or coupled topatient 102 (e.g., a wearable band around a torso of patient 102, an external patch secured to the torso of patient 102). Sensor(s) 202 may sense signals from patient 102 and may include, but are not limited to, glucose monitors, electrodes, oximeters, microphones, optical sensors, or the like. Sensor(s) 202 may sense signals corresponding to one or more physiological parameters of patient 102 including, but are not limited to, an electrocardiogram (ECG) signal from heart 104, blood pressure levels of patient 102, oxygen saturation levels of patient 102, electrical signals in nerves of patient 102, brain activity of patient 102, and / or glucose levels of patient 102.

[0044] Sensing circuitry 204 may be electrically coupled to sensor(s) 202 and / or some or all of sensing / therapy elements 114. Sensing circuitry 204 may sense signals (e.g., electrical signals) corresponding to one or more physiological parameters of patient 102 via one or more of sensor(s) 202 and / or one or more sensing / therapy elements 114(e.g., via one or more electrodes of sensing / therapy elements 114. Sensing circuitry 204 may process the obtained signals to determine physiological parameter values. Sensing circuitry 204 may transmit the obtained signals to processing circuitry 208, which may determine the physiological parameter values based at least in part on the obtained signals.

[0045] The components of sensing circuitry 204 may be analog components, digital components, or a combination thereof. Sensing circuitry 204 may, for example, include one or more sense amplifiers, filters, rectifiers, threshold detectors, analog-to-digital converters (ADCs) or the like. Sensing circuitry 204 may convert the sensed signals to digital form and provide the digital signals to processing circuitry 208 for processing or analysis. For example, sensing circuitry 204 may amplify signals from the sensing electrodes and convert the amplified signals to multi-bit digital signals by an ADC. In some examples, wherein IMD 106 is configured to sense cardiac signals from heart 104, sensing circuitry 204 may compare processed signals to a threshold to detect the existence of atrial or ventricular depolarizations (e.g., P- or R waves) and indicate the existence of the atrial depolarization (e.g., P-waves) or ventricular depolarizations (e.g., R-waves) to processing circuitry 208.

[0046] Processing circuitry 208 may process the signals from sensing circuitry 204 to monitor electrical activity of heart 104 or other physiological activities of patient 102. Processing circuitry 208 may receive signals from sensor(s) 202 via sensing circuitry 204 and may process the received signals from sensor(s) 202 to determine a posture of patient102. In some examples, IMD 106 may be implanted within patient 102 such that posture of patient 102 (e.g., standing, supine) may not perfectly align with a sensing axis of sensor(s) 202 (e.g., a sensing axis of accelerometer(s) 203). For example, an outer surface of IMD 106 may not be parallel to a frontal axis or another reference axis of patient 102. In such examples, processing circuitry 208 may receive user input (e.g., from the user, from the clinician) to correspond one or more sensed orientations to one or more postures (e.g., to correspond a first orientation to a standing posture, to correspond a second orientation to a supine posture). Processing circuitry 208 may determine the posture of patient 102 based at least in part on detected changes from the one or more stored orientations. In some examples, patient 102 may not be perfectly in a specific posture but may be substantially in the posture. For example, patient 102 may be standing but may be leaning in one direction. In another example, patient 102 may be supine but may be recline on an inclined surface. Processing circuitry 208 may assign, for each posture state, a range of orientations (e.g., a range of angles detected by sensor(s) 202) and may determine the current posture of patient 102 based at least in part on an overlap between a sensed orientation from sensor(s) 202 (e.g., a sensed angle) and the range of orientations for a specific posture. Processing circuitry 208 may store various posture states and the corresponding orientation and / or ranges of orientations in memory 212.

[0047] Processing circuitry 208 may store signals obtained by sensing circuitry 204 as well as any data derived based on the sensed signals (e.g., generated electrogram (EGM) waveforms, marker channel data, blood oxygen level, blood glucose level, brain activity, blood pressure level, nerve electrical signal activity, and / or posture of patient 102) in memory 212. Processing circuitry 208 may analyze the EGM waveforms and / or marker channel data to detect arrhythmias (e.g., bradycardia or tachycardia). In other examples, processing circuitry 208 may determine an occurrence of a medical condition by at least comparing a sensed signal to a threshold condition stored in memory 212. In response to detecting an advent of a medical condition (e.g., an arrhythmia), processing circuitry 208 may control therapy delivery circuitry 206 to deliver medical therapy to the target tissue of patient 102 via one or more of sensing / therapy elements 114. For example, in response to detecting a cardiac event, processing circuitry 208 may control therapy delivery circuitry 206 to deliver the desired therapy to treat the cardiac event, e.g., defibrillation shock,cardioversion shock, or cardiac pacing (e.g., antitachycardia pacing (ATP), post shock pacing, or bradycardia pacing).

[0048] Processing circuitry 208 may adjust one or more sensing parameter values based at least in part on the posture of patient 102. Sensing parameter values may correspond to one or more sensing parameters. The one or more sensing parameters may include, but are not limited to, sensing thresholds, threshold timings, sensing sensitivity, or sensing vectors. Processing circuitry 208 may control sensing circuitry 204 to sense signals from patient 102 along one or more sensing vectors. A sensing threshold may correspond to a threshold amplitude of one or more electrical signals of heart 104 indicative of an onset of a cardiac event (e.g., of an arrhythmia). Threshold timings may correspond to a threshold timing between adjacent electrical signals and / or portions of the electrical signal (e.g., portions of a QRS complex of electrical signals of heart 104) indicative of an onset of a cardiac event. Processing circuitry 208 may adjust one or more sensing parameter values based on the posture of patient 102 to reduce oversensing or under- sensing of signals by sensing circuitry 204 due to changes in distance between a target tissue (e.g., heart 104) and IMD 106 (e.g., housing of IMD 106, sensing element(s) of IMD 106, sensing / therapy elements 114 of system 100). For example, processing circuitry 208 may adjust one or more sensing parameter values to reduce oversensing or under-sensing by sensing circuitry 204.

[0049] Processing circuitry 208 may store sensing parameter values corresponding to different posture states in memory 212. Posture states may include standing, sitting, crouching, supine, or the like. Different posture states may have the same or different sensing parameter values. Processing circuitry 208 may receive, via communication circuitry 210, sensing parameter values and accompanying data from an external device (e.g., from an external programmer operated by a clinician). The data may indicate, for each sensing parameter values, one or more corresponding postures. The sensing parameter values may be determined based on sensed signals from patient 102 while patient 102 is in different postures. In some examples, the sensing parameter values are determined based at least in part on sensed signals from a plurality of other patients physiologically similar to patient 102 (e.g., having a same or similar height, weight, age, sex, and / or build as patient 102). Processing circuitry 208 may receive, via communication circuitry 210, default sensing parameter values and accompanying data from the externaldevice. Processing circuitry 208 may store the received sensing parameter values and accompanying data in memory 212.

[0050] When processing circuitry 208 determines a posture of patient 102 or a change in the posture of patient 102, processing circuitry 208 may retrieve, from memory 212, sensing parameter values corresponding to the current posture of patient 102. Processing circuitry 208 may control sensing circuitry 204 to sense signals from patient 102 bast at least in part on the retrieved sensing parameter values. In some examples, patient 102 may be in a posture not stored in memory 212. In such examples, processing circuitry 208 may retrieve, from memory 212 default sensing parameter values and control sensing circuitry 204 to sense signals from patient 102 based at least in part on the retrieved default sensing parameter values. The default sensing parameter values may be independent of posture of patient 102.

[0051] Therapy delivery circuitry 206 is configured to generate and deliver medical therapy to a target tissue of patient 102. For example, therapy delivery circuitry 206 is configured to deliver electrical therapy to heart 104. In some examples, therapy delivery circuitry 208 is configured to deliver medical therapy to other target tissue in patient 102. The medical therapy may include delivery of, but are not limited to, a chemical substance, electrical energy, thermal energy, radiofrequency (RF) energy, microwave energy, or cryogenic energy to the target tissue.

[0052] Therapy delivery circuitry 206 may include one or more pulse generators, capacitors, and / or other components capable of generating and / or storing energy to deliver as medical therapy (e.g., pacing therapy, defibrillation therapy, cardioversion therapy, cardiac resynchronization therapy, other therapy, or a combination of therapies). In some instances, therapy delivery circuitry 206 may include a first set of components configured to provide pacing therapy and a second set of components configured to provide defibrillation therapy. In some instances, therapy delivery circuitry 206 may utilize the same set of components to provide both pacing and defibrillation therapy. In still other instances, therapy delivery circuitry 206 may share some of the defibrillation and pacing therapy components while using other components solely for defibrillation or pacing. Processing circuitry 208 may control therapy delivery circuitry 206 to deliver the generated therapy to heart 104 via one or more combinations of sensing / therapy elements 114. Although not shown in FIG. 3, IMD 106 may include switching circuitryconfigurable by processing circuitry 208 to control which of sensing / therapy elements 114 are connected to therapy delivery circuitry 206 and sensing circuitry 204.

[0053] Processing circuitry 208 may adjust therapy delivery parameter values (e.g., pacing parameter values) based at least in part on the posture of patient 102. Pacing parameter values may correspond to one or more pacing parameters. Pacing parameters may include, but are not limited to, a pacing amplitude, a pacing pulse width, a pacing frequency; or a pacing vector. Processing circuitry 208 may control therapy delivery circuitry 206 to deliver cardiac pacing to heart 104 to capture cardiac tissue of heart 104 without unnecessarily expending power and / or causing patient discomfort.

[0054] Processing circuitry 208 may determine, for each posture state, therapy delivery parameter values by performing a therapy delivery management test. Processing circuitry 208 may control communication circuitry 210 to output an alert to one or more external devices. The alert may indicate that IMD 106 is currently or will perform a therapy delivery management test and may indicate a time at which the therapy delivery management test will being and / or a duration of the therapy delivery management test. The alert may notify patient 102 of potential discomfort arising from the therapy delivery management test and may provide, to patient 102, activities to avoid during the therapy delivery management test (e.g., operating a motor vehicle). Processing circuitry 208 may control communication circuitry 210 to output the alert at least a period of time (e.g., 30 minutes, 1 hour, 24 hours) prior to the start of the therapy delivery management test. Processing circuitry 208 may, in response to receiving user input via communication circuitry 210, delay or cancel the therapy delivery management test.

[0055] During the therapy delivery management test, processing circuitry 208 may generate, for each therapy delivery parameter, one or more test therapy delivery parameter values. Processing circuitry 208 may control therapy delivery circuitry 206 to deliver medical therapy to the target tissue based on varying combinations of test therapy delivery parameter values and select test therapy delivery parameter values sufficient to efficaciously deliver medical therapy to the target tissue. For each posture, the determined therapy delivery parameter values may correspond to a minimum medical therapy duration, frequency, and / or magnitude that corresponds to a delivered medical therapy capable of achieving a threshold level of efficacy (e.g., 90% chance of efficacy, 95% chance of efficacy). For example, processing circuitry 208 may determine, for eachposture, a minimum pacing amplitude, pacing pulse width, and / or pacing pulse frequency sufficient to capture cardiac tissue of heart 104. When determining therapy delivery parameter values, processing circuitry 208 may adjust the selected test therapy delivery parameter values such that the determined therapy delivery parameter values are separated from the minimum required parameter values (e.g., the test therapy delivery parameter values) by at least a threshold margin (e.g., by at least 5%, by at least 10%), e.g., to ensure efficacy of medical therapy delivered based on the determined therapy delivery parameter values. Processing circuitry 208 may store the determined therapy delivery parameter values and corresponding data in memory 212. The corresponding data may indicate, for each stored therapy delivery parameter value, a corresponding posture and a time stamp for when the therapy delivery management test was conducted.

[0056] Processing circuitry 208 may, for each posture state, perform the therapy delivery management test regularly (e.g., every 24 hours, every 2 days, every 3 days, every week), e.g., to account for changes in physiology and / or disease state of patient 102. For each posture state, processing circuitry 208 may automatically perform the therapy delivery management test based on a determination by processing circuitry 208 that the test has not been performed within a threshold period of time (e.g., within the past 24 hours). Processing circuitry 208 may determine whether the therapy delivery management test has been performed within the threshold period of time upon determining that patient 102 is in the respective posture. Processing circuitry 208 may perform therapy delivery management tests as patient 102 assumes the respective postures, e.g., in an ambulatory setting.

[0057] In some examples, processing circuitry 208 determines, based on received signals from sensing circuitry 204, a posture of patient 102 and retrieves, from memory 212, therapy delivery parameter values corresponding to the determined posture. Processing circuitry 208 may determine whether the retrieved therapy delivery parameter values were determined within a threshold period of time from a current time. If the retrieved therapy delivery parameter values were determined within the threshold period of time, processing circuitry 208 may control therapy delivery circuitry 206 to deliver medical therapy to patient 102 based on the retrieved therapy delivery parameter values. If the retrieved therapy delivery parameter values were not determined within the threshold period of time, processing circuitry 208 may perform the therapy delivery managementtest to determine updated therapy delivery parameter values and control therapy delivery circuitry 206 to deliver medical therapy to patient 102 based on the updated therapy delivery parameter values. Processing circuitry 208 may cause therapy delivery circuitry 206 to deliver medical therapy to patient 102 based on the outdated therapy delivery parameter values or based on default therapy delivery parameter values until the therapy delivery management test is completed or if there is insufficient time to complete the therapy delivery management test.

[0058] Communication circuitry 210 may include any suitable hardware, firmware, software, or any combination thereof for communicating with another device, such as a clinician programmer, a patient monitoring device, or the like. For example, communication circuitry 210 may include appropriate modulation, demodulation, frequency conversion, filtering, and amplifier components for transmission and reception of data with the aid of an antenna. Communication circuitry 210 may communicate with another implantable device and / or an external device of system 100 via one or more wireless communications standards or protocols, including, but are not limited to, 3G, 4G, 5G, Wi-Fi (e.g., 802.11 or 802.15 ZigBee), Bluetooth®, or Bluetooth® Low Energy (BLE).

[0059] The various components of IMD 106 may include any one or more processors, controllers, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or equivalent discrete or integrated circuitry, including analog circuitry, digital circuitry, or logic circuitry. Processing circuitry 208 may include fixed function circuitry and / or programmable processing circuitry. The functions attributed to processing circuitry 208 herein may be embodied as software, firmware, hardware, or any combination thereof.

[0060] Memory 212 may include computer-readable instructions that, when executed by processing circuitry 208 or other components of IMD 106, cause one or more components of IMD 106 to perform various functions attributed to those components in this disclosure. Memory 212 may include any volatile, non-volatile, magnetic, optical, or electrical media, such as a random-access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), static non-volatile RAM (SRAM), electrically-erasable programmable ROM (EEPROM), flash memory, or any other non-transitory computer- readable storage media.

[0061] FIG. 4 is a flow chart illustrating an example process of adjusting sensing parameter values of an example IMD system 100 based on changes in patient posture. While the example process in FIG. 4 is primarily described with reference to sensing cardiac signals from heart 104 of patient 102, the example process illustrated in FIG. 4 may be performed by other example IMD systems configured to sense other signals from target tissue of patient 102, as described herein. While the example process illustrated in FIG. 4 is primarily described as being performed by IMD 106 (e.g., by processing circuitry 208 of IMD 106), the example process may be performed by one or more other computing devices within system 100, including one or more external computing devices configured to communicate with IMD 106.

[0062] System 100 may determine sensing parameter values for each of two or more different posture states (302). Posture states may include, but are not limited to, standing, sitting, crouching, supine, or the like. In some examples, posture states may be defined based on different zones of sphere-based 3-axis accelerometer measurements. Across the different posture states, the distances between a target tissue in patient 102 and IMD 106 and / or components coupled to IMD 106 of system 100 may vary. For example, the distance may be greater when patient 102 is in a supine posture state compared to a crouching posture state. System 100 (e.g., processing circuitry 208 of IMD 106) may determine, for each posture state, sensing parameter values for one or more sensing parameters. Sensing parameters may include sensing thresholds, threshold timings, sensing sensitivity, or sensing vectors. For each posture state, the determined sensing parameter values may account for the distance between IMD 106 (e.g., between sensor(s) 202 and / or sensing / therapy elements 114 of system 100) and the target tissue (e.g., heart 104 of patient 102). For example, system 100 may adjust sensing parameter values to increase sensing sensitivity when the distance increases as a result of a change in posture state, or vice versa. Sensing parameter values may be same or different between different posture states. In some examples, system 100 receives, from one or more external devices (e.g., from a clinician programmer, a patient monitoring device, or the like), sensing parameter values corresponding to each of the different posture states. A clinician may enter the sensing parameter values into system 100 via the one or more external devices. The received sensing parameter values may be stored in memory of system 100 (e.g., inmemory 212 of IMD 106). For each stored sensing parameter value, system 100 may assign one or more corresponding posture state.

[0063] In some examples, the determined sensing parameter values for each posture state may include one or more sensing templates. Each sensing template may include, but are not limited to, specific sensing parameter values for the sensing template. Each sensing template may correspond to identification of one or more medical conditions experienced by patient 102. Each sensing template may include one or more sensing criteria for a corresponding medical condition. Sensing criteria may include, but are not limited to, a threshold behavior of a sensed signal that satisfies the specific sensing parameter values stored in the sensing template. For each posture, system 100 may store two or more different sensing templates, wherein each sensing template may correspond to identification of a different medical condition.

[0064] In some examples, sensing templates include one or more EGM morphology discrimination templates. System 100 may apply an EGM morphology discrimination template to identify cardiac medical conditions experienced by patient 102 based on a comparison between a cardiac signal and a morphology of an EGM signal, as stored in the EGM morphology discrimination template. Example EGM morphology discrimination templates may include instructions to apply one or more algorithms including, but are not limited to, a Wavelet EGM discrimination algorithm.

[0065] System 100 may receive sensed signals from sensor(s) 202 (304). Sensor(s) 202 may include accelerometer(s) 203 and / or other sensors configured to determine a position and / or an orientation of IMD 106 and / or sensing / therapy elements 114 of system 100. The other sensors may include, but are not limited to, accelerometers, gyroscopes, or IMUs. The sensed signals may indicate a position and / or an orientation of sensor(s) 202 and, by extension, the position and / or orientation of IMD 106 and / or sensing / therapy elements 114. The sensed signals may indicate changes in position and / or changes in orientation of sensor(s) 202 over time and, by extension, changes in the position and / or orientation of IMD 106 and / or sensing / therapy elements 114 over time. In some examples, sensor(s) 202 may be disposed within another IMD of system 100 and / or may be disposed on an external or wearable device of system 100. For example, sensor(s) 202 may be disposed on a band worn around a torso of patient 102. In such examples, sensor(s) 202may be in wireless communication with IMD 106 and may transmit the sensed signals to IMD 106 (e.g., to processing circuitry 208 of IMD 106).

[0066] System 100 may determine, based at least in part on the received sensed signals, a posture of patient 102 (306). System 100 (e.g., processing circuitry 208 of IMD 106 of system 100) may determine, based on the sensed signals, the position, the orientation, the change in position, and / or the change in orientation of IMD 106 and / or of sensing / therapy elements 114. System 100 may compare the determined position and / or orientation of IMD 106 and / or of sensing / therapy elements 114 against ranges of stored positions and / or orientations of posture states and determine a current posture of patient 102 based on an overlap between the determined position and / or orientation and the ranges of stored positions and / or orientations for a specific posture state. For example, system 100 may determine that patient 102 is standing based on a determination that the determined orientation of IMD 106 overlaps with a range of orientations for a standing posture state stored in system 100. Each posture state may correspond to a range of positions and / or orientations due to the possibility of variations in the body position of patient 102 in a specific posture. For example, patient 102 may be leaning in a direction while standing.

[0067] IMD 106 may be implanted within patient 102 at a specific location and orientation such that IMD 106 and / or sensing / therapy elements 114 are offset from one or more anatomical planes of patient 102. For example, IMD 106 may be offset from a frontal plane of patient 102 such that an outer surface of IMD 106 is not parallel to the frontal plane of patient 102. In such examples, the clinician may enter posture states of patient 102 into system 100 via one or more external devices during and / or post implantation of IMD 106. System 100 may associate positions and / or orientations of IMD 106 at specific times with the posture states received by system 100 during the specific times. For example, system 100 may associate a first orientation of IMD 106 with a standing posture based on a determination that IMD 106 is in the first orientation during a first time period and based on receiving, from one or more external devices, that patient 102 is standing during the first time period. System 100 may determine a current posture of patient 102 based at least in part on determined deviations in position and / or orientation from one or more orientations associated with a known posture as stored in system 100and / or overlap between the determined position and / or orientation with positions and / or orientations associated with the known posture.

[0068] System 100 may receive the ranges of positions and / or orientations for each posture state or may determine the ranges of positions and / or orientations based on a specific posture and / or orientation associated with each posture state. For example, System 100 may determine the range of possible orientations for the standing posture as all possible orientations of IMD 106 and / or sensing / therapy elements 114 within a threshold tolerance range of the first orientation (e.g., all orientations of IMD 106 defining an angular position within the threshold tolerance range of the first angular position of the first orientation). The threshold tolerance range may be up to about ± 10%. In some examples, the threshold tolerance range is up to about ±5%. The threshold tolerance range may be uniform across two or more different posture states or may be unique to each posture state.

[0069] System 100 may determine whether sensing parameter values corresponding to the determined posture are stored in IMD 106 (308). System 100 may determine whether there is a match between the determined posture and a stored posture. System 100 may determine, based on a match between the determined posture and the stored posture, whether any sensing parameter values corresponding to the posture are stored. For example, when system 100 determines that patient 102 is standing, system 100 may determine if any of the stored sensing parameter values correspond to a standing posture state. In response to determining that sensing parameter values corresponding to the determined posture are not stored in IMD 106 (“NO” branch of 308), system 100 may adjust sensing parameters to default sensing parameter values (310A). Default sensing parameter values may be stored in system 100 (e.g., in memory 212 of system 100) and may be independent of the posture of patient 102. Default sensing parameter values may include values corresponding to one or more of sensing parameters.

[0070] In response to determining that sensing parameter values corresponding to the determined posture are stored in IMD 106 (“YES” branch of 308), system 100 may adjust sensing parameters to sensing parameter values corresponding to the posture (310B). System 100 may retrieve (e.g., from memory 212) stored sensing parameter values corresponding to the determined posture. For example, in response to determining that patient 102 is standing, system 100 may retrieve stored sensing parameter valuescorresponding to the standing posture state. System 100 may then adjust sensing parameters to the retrieve sensing parameter values.

[0071] In some examples, patient 102 may only transition between postures or transition to a specific posture for a transient amount of time (e.g., less than one minute). In such examples system 100 may determine an amount of time that patient 102 has been in the determined posture and may adjust sensing parameters if patient 102 has been in the determined posture for at least a minimum threshold time period. The minimum threshold time period may be up to five minutes, e.g., up to one minute. System 100 may adjust sensing parameters to sensing parameter values corresponding to the posture (310B) in response to satisfaction of the minimum threshold time period.

[0072] In some examples, the posture of patient 102 may be constantly changing (e.g., patient 102 is in each of a plurality of postures for the transient amount of time). For example, patient 102 may transition from a first posture (e.g., standing) to alternating between a second posture (e.g., prone) and a third posture (e.g., crouching). In such examples, patient 102 may be in neither the second posture nor the third posture for a sufficient amount of time to satisfy the minimum threshold time period, but is no longer in the first posture. In some examples, system 100 may determine, based on a determined change in posture, a period of time between a current time and the determined change in posture system 100 may adjust sensing parameters to default sensing parameter values (310A) in response to a determination that the period of time between the current time and the determined change in posture is greater than or equal to a maximum threshold time period. The maximum threshold time period may be up to five minutes, e.g., up to one minute.

[0073] System 100 may determine that the maximum threshold time period has not been satisfied based on a determination that patient 102 has been in the determined posture for at least the minimum threshold time period. System 100 may not determine whether the maximum threshold time period has been satisfied if system 100 determines that patient 102 is in a specific posture (e.g., either the second posture or the third posture) after the determined change in posture from the first posture. System 100 may determine whether the maximum threshold time period has been satisfied if system 100 determines that there was a change in posture from the first posture and that patient 102 is notremaining in a specific posture after the change in posture (e.g., patient 102 is alternating between the second posture and the third posture after the change in posture).

[0074] System 100 may sense electrical signals from patient 102 based on the adjusted sensing parameter values when patient 102 is in the posture (312). IMD 106 of system 100 may sense electrical signals from target tissue of patient 102 (e.g., from heart 104) based on the adjusted sensing parameter values. For example, processing circuitry 208 of IMD 106 may control sensing circuitry 204 to sense electrical signals from heart 104 via sensor(s) 202, sensing element(s) and / or therapy delivery element(s) and based on the adjusted sensing parameter values. For example, processing circuitry 208 may control sensing circuitry 204 to sense electrical signals along sensing vectors indicated in the adjusted sensing parameter values. In some examples, processing circuitry 208 may identify onsets of one or more medical conditions based at least in part on satisfaction of sensing thresholds and / or sensing timings by the sensed electrical signals, wherein the sensing thresholds and / or sensing timings are indicated by the adjusted sensing parameter values.

[0075] In some examples, where system 100 stores sensing templates for various postures, system 100 may determine whether one or more stored sensing templates for the determined posture have been generated, verified, or updated within a threshold period of time prior to the current time. System 100 may verify a sensing template based on clinician input and / or receiving information from one or more external devices and / or systems confirming a determination made by system 100 based on application of the sensing template. System 100 may update a sensing template by adjusting one or more sensing parameter values and / or sensing criteria stored in the sensing template, e.g., in response to changes in sensed signals over time, in response to changes in patient physiology and / or disease state. If the sensing template has not been generated verified, or updated within the threshold period of time, system 100 may update the sensing template prior to applying the sensing template to the sensed electrical signals. In some examples, where there is insufficient time for system 100 to update the sensing template, system 100 may apply the outdate sensing template and / or a default sensing template to the sensed electrical signals, The threshold period of time may be up to 24 hours, 1 week, or 1 month.

[0076] System 100 may continue to sense electrical signals (e.g., constantly, periodically) from patient 102 based on the adjusted sensing parameter values whilepatient 102 is in the same posture. System 100 may continue to receive sensed signals from sensor(s) of IMD 106 (304) and implement steps 304-312 to adjust sensing parameter values as the posture of patient 102 changes over time.

[0077] FIG. 5 is a flow chart illustrating an example process of adjusting pacing parameter values of an example IMD system 100 based on changes in patient posture. While the example process in FIG. 5 is primarily described with reference to delivering cardiac pacing therapy to heart 104 of patient 102, the example process illustrated in FIG. 5 may be performed by other example IMD systems to deliver other medical therapy to target tissue of patient 102, as described herein. For example, system 100 may implement the process illustrated in FIG. 5 to perform therapy delivery management tests and determine therapy delivery parameter values, e.g., as previously described herein. While the example process illustrated in FIG. 5 are primarily described as being performed by IMD 106 (e.g., by processing circuitry 208 of IMD 106), the example process may be performed by one or more other computing devices within system 100, including one or more external computing devices.

[0078] System 100 may generate pacing parameter values for each of two or more posture states via a pacing management test (402). Pacing parameter values may correspond to one or more pacing parameters including, but are not limited to, pacing amplitude, pacing pulse width, pacing voltage, pacing frequency, or pacing vectors. During the pacing management test, system 100 may determine, for each posture state, minimum pacing parameter values required to capture cardiac tissue of heart 104 of patient 102. For example, system 100 may determine the minimum pacing amplitude and / or pacing pulse width required to capture the cardiac tissue when patient 102 is standing, when the patient is sitting, etc. System 100 may select a plurality of test pacing parameter values for each of one or more pacing parameters. System 100 may deliver a plurality of electrical therapies to heart 104, each electrical therapy being defined by a different combination of test pacing parameter values. The electrical therapy may include, but are not limited to, cardiac pacing therapy or cardiac shock therapy. System 100 may iteratively select test pacing parameter values and deliver electrical therapies to heart 104 based on the selected test pacing parameter values until system 100 determines the minimum pacing parameter values corresponding to an electrical therapy configured todeliver a minimum amount of electrical energy to capture the cardiac tissue. The pacing management test may be performed by processing circuitry 208 of IMD 106.

[0079] In some examples, a clinician may perform the pacing management test and may enter the determined pacing parameter values into system 100 (e.g., into IMD 106 of system 100) via a clinician programmer, a patient monitoring device, or the like. In some examples, system 100 (e.g., IMD 106 of system 100) may automatically perform the pacing management test, e.g., after a threshold period of time has elapsed since a prior test, after detection of changes in one or more physiological signals of the patient. System 100 may notify patient 102 of the test and may instruct patient 102 to assume various postures. Once patient 102 has assumed each posture, System 100 may perform the pacing management test for the respective posture. System 100 may perform the pacing management test until system 100 has determined pacing parameter values for one or more posture states stored in system 100. In some examples, system 100 may perform the pacing management test when patient 102 is in an ambulatory setting, e.g., whenever patient 102 assumes the respective postures during normal daily activities.

[0080] Once system 100 determines the pacing parameter values, system 100 may store the pacing parameter values in the memory of system 100 (e.g., in memory 212). The stored pacing parameter values may be unaltered, e.g., may be the minimum pacing parameter values determined by system 100 during the pacing management test. In some examples, system 100 may adjust the minimum pacing parameter values such that each adjusted pacing parameter value is greater than the respective minimum pacing parameter value by at least a threshold margin. For example, for each posture, system 100 may determine an adjusted pacing amplitude, an adjusted pacing pulse width, an adjusted pacing voltage, and / or an adjusted pacing frequency that are greater than the minimum pacing amplitude, the minimum pacing pulse width, the minimum pacing voltage and / or the minimum pacing frequency by at least the threshold margin, respectively. The threshold margin may be a percentage of the minimum pacing parameter value (e.g., 5%, 10%, 15%). The threshold margin may be uniform for two or more pacing parameters or may be unique to each pacing parameter. System 100 may then store the adjusted minimum pacing parameters in the memory of system 100.

[0081] System 100 may store in the memory, for each stored pacing parameter value, corresponding data. The corresponding data may indicate, for each stored pacingparameter value, one or more postures states associated with the value and a timestamp corresponding to when system 100 determined the respective pacing parameter value. When system 100 determined the respective pacing parameter value may be a time when system 100 performed the pacing management test during which system 100 determined the respective pacing parameter value.

[0082] System 100 may receive sensed signals from sensor(s) 202 (404). System 100 may determine, based at least in part on the sensed signals, a posture of patient 102 (406). System may receive sensing signals from sensor(s) 202 and determine the posture of patient 102 in accordance with the example process illustrated in steps 304 and 306 of FIG. 4, respectively, and as previously described in greater detail herein.

[0083] System 100 may determine whether pacing parameter values correspond to the determined posture are stored in system 100 (408). For example, when system 100 determines that patient 102 is standing, system 100 may determine if any of the stored pacing parameter values correspond to a standing posture state.

[0084] In response to a determination that the pacing parameter values corresponding to the posture are not stored in system 100 (“NO” branch of 408), system 100 may determine updated pacing parameter values for the posture (412A). System 100 may determine updated pacing parameter values for the posture by performing a pacing management test when patient 102 is in the posture. Once system 100 determines the updated pacing parameter values, system 100 may store the updated pacing parameter values and corresponding date in the memory of system 100.

[0085] In response to a determination that the pacing parameter values corresponding to the posture are stored in system 100 (“YES” branch of 408), system 100 may determine whether the pacing parameter values were generated (e.g., by a pacing management test) within a threshold period of time from the current time (410). System 100 may retrieve and compare a timestamp corresponding to the retrieved pacing parameter values against a current time (e.g., as determined by system 100, as received by system 100) to determine if the retrieved pacing parameter values were generated within the threshold period of time from the current time. The threshold period of time may be dependent on the type of medical therapy delivered to patient 102 and / or a severity of a medical condition the medical therapy is configured to address. The threshold period of time may be up to about 24 hours. In some examples, the threshold period of time may be up to about 1 week. Eachposture state may be analyzed independently. For example, a determination that the pacing parameter values for a standing posture state were not generated within the threshold period of time from the current time does not affect the determination of whether the pacing parameter values for a supine posture state were generated within the threshold period of time from the current, or vice versa.

[0086] In response to a determination that the pacing parameter values were not generated within a threshold period of time from the current time (“NO” branch of 410), system 100 may determine updated pacing parameter values for the posture (412A). System 100 may determine updated pacing parameter values for the posture by performing a pacing management test when patient 102 is in the posture. Once system 100 determines the updated pacing parameter values, system 100 may store the updated pacing parameter values and corresponding date in the memory of system 100.

[0087] In response to a determination that the pacing parameter values were generated within a threshold period of time from the current time (“YES” branch of 410), system 100 may retrieve the pacing parameter values for the posture (412B). System 100 may retrieve the pacing parameter values stored in the memory of system 100, e.g., stored in memory 212.

[0088] System 100 may deliver electrical therapy to patient 102 based on the pacing parameter values (414). The electrical therapy may include, but are not limited to, cardiac pacing therapy or cardiac shock therapy. In some examples, processing circuitry 208 of IMD 106 may control therapy delivery circuitry 206 to deliver electrical therapy defined by the retrieved pacing parameter values. For example, processing circuitry 208 may adjust existing pacing parameter values to the retrieved pacing parameter values and control therapy delivery circuitry 206 to deliver the electrical therapy based on the retrieved pacing parameter values (e.g., based on retrieved pacing amplitudes, pacing pulse widths, pacing voltages, pacing frequencies, and / or pacing vectors). Therapy delivery circuitry 206 may generate electrical energy in accordance with the retrieved pacing parameter values and deliver the electrical energy to tissue of patient 102 via one or more of sensing / therapy elements 114. The electrical energy may travel from the one or more sensing / therapy elements 114 through tissue of patient 102 and into cardiac tissue of heart 104.

[0089] In some examples, there may be insufficient time for system 100 to generate updated pacing parameter values via application of the pacing management test. In such examples, system 100 may retrieve and apply prior pacing parameter values for the posture or default pacing parameter values to deliver electrical therapy to patient 102. Prior pacing parameters may include pacing parameter values generated by system 100 at least the threshold period of time (e.g., at least 24 hours) prior to the current time. Default pacing parameter values may be independent of posture of patient 102. System 100 may deliver electrical therapy, as needed, to patient 102 based on the prior pacing parameters or the default pacing parameters until system 100 completes the pacing management test for the posture. After the pacing management test is complete, system 100 may apply the updated pacing parameter values and deliver further electrical therapy in accordance with the updated pacing parameter values.

[0090] In some examples, e.g., as previously described herein with respect to FIG. 4, patient 102 may only transition between postures or transition to a specific posture for a transient amount of time (e.g., less than one minute). In such examples, system 100 may retrieve the pacing parameter values for the posture (412B) in response to a determination of a satisfaction of the minimum threshold time period.

[0091] In some examples, e.g., as previously described herein with respect to FIG. 4, the posture of patient 102 may be constantly changing (e.g., patient 102 is in each of a plurality of postures for the transient amount of time). In such examples, system 100 may adjust pacing parameters to default pacing parameter values in response to a determination that the period of time between the current time and the determined change in posture is greater than or equal to a maximum threshold time period. System 100 may determine whether the minimum threshold time period or the maximum threshold time period has been satisfied in accordance with the example processes previously described herein with respect to FIG. 4.

[0092] System 100 may iteratively perform steps 404-414 to deliver electrical therapy to patient 102. System 100 may continue to receive sensed signals from sensor(s) 202 of IMD 106 (404) and determine, based at least in part on the sensed signals, the posture of patient 102 (406). System 100 may determine changes in posture of patient 102 and may implement steps 406-414 to adjust pacing parameter values based on the change in posture of patient 102.

[0093] FIG. 6 is a flow chart illustrating an example process of adjusting sensing parameter values and pacing parameter values of an example IMD system 100 based on changes in patient posture. While the example process illustrated in FIG. 6 are primarily described as being performed by IMD 106 (e.g., by processing circuitry 208 of IMD 106), the example process may be performed by one or more other computing devices within system 100, including one or more external computing devices.

[0094] System 100 may receive sensed signals from sensor(s) 202 (502) and determine, based at least in part on the sensed signals, a posture of patient 102 (504). System 100 may receive sensed signals from sensor(s) 202 and determine the posture of patient 102 in accordance with one or more example processes previously described herein, e.g., as described with respect to FIGS. 3 and 4.

[0095] System 100 may sense electrical signals from patient 102 in accordance with sensing parameter values corresponding to the posture of patient 102 (506). System 100 may determine, adjust, or select, based at least in part on the posture of patient 102, sensing parameter values for the posture. System 100 may sense electrical signals from patient 102 in accordance with the sensing parameter values for the posture. For example, processing circuitry 208 of IMD 106 of system 100 may control sensing circuitry 204 to sense electrical signals from a target tissue (e.g., heart 104) of patient 102 based on the sensing parameter values corresponding to the posture. System 100 may determine, adjust, or select sensing parameter values for a posture of patient 102 in accordance with one or more example processes described herein, e.g., as described with respect to FIGS. 3 and 4.

[0096] System 100 may determine whether the sensed electrical signals satisfy one or more threshold conditions for delivery of medical therapy (508). System 100 may analyze the sensed electrical signals to identify one or more physiological signals, including, but are not limited to, cardiac signals. For example, system 100 may convert the sensed electrical signals into EGM waveforms and / or marked channel data. System 100 may analyze the physiological signals (e.g., EGM waveforms and / or marker channel data) and determine whether the physiological signals satisfy one or more threshold conditions indicative of an onset and / or an occurrence of a cardiac condition such as arrhythmia (e.g., bradycardia or tachycardia). Threshold conditions may include, but are not limited to, a threshold timing of one or more phases of the cardiac signal (e.g., one or more portions or a QRS complex of an EGM waveform), a threshold amplitude of one or more phases ofthe cardiac signal, or one or more other threshold conditions corresponding to an onset or an occurrence of a cardiac condition.

[0097] Based on a determination that the sensed electrical signals do not satisfy the one or more threshold conditions (“NO” branch of 508), system 100 may continue to receive sensed signals from sensor(s) 202 of IMD 106 (502) and sense electrical signals from patient 102 in accordance with steps 504-506. Based on a determination that the sensed electrical signals satisfy the one or more threshold conditions (“YES” branch of 508), system 100 may deliver medical therapy to patient 102 in accordance pacing parameter values corresponding to the posture (510). The medical therapy may include an electrical therapy configured to restore a heart rhythm of heart 104 back to a baseline heart rhythm. The electrical therapy may include, but are not limited to, cardiac pacing therapy or cardiac shock therapy. System 100 may determine, adjust, or select pacing parameter values based on posture of patient 102 in accordance with one or more example processes described herein, e.g., as described with respect to FIGS. 3 and 5.

[0098] System 100 may iteratively implement steps 502-510 to sense electrical signals from patient 102 and deliver medical therapy to patient 102 based on the sensed electrical signals. In accordance with the process illustrated in FIG. 5, system 100 may iteratively implement steps 502-510 to detect changes in posture of patient 102, adjust sensing parameter values and pacing parameter values based on the new posture, and sense electrical signals from patient 102 and deliver medical therapy to patient 102 based on the adjusted sensing parameter values and pacing parameter values, respectively.

[0099] In some examples, e.g., as previously described herein with respect to FIG. 4, patient 102 may only transition between postures or transition to a specific posture for a transient amount of time (e.g., less than one minute). In such examples, system 100 may adjust sensing parameter values and / or pacing parameter values corresponding to the posture of patient 102 based on satisfaction of the minimum threshold time period.

[0100] In some examples, e.g., as previously described herein with respect to FIG. 4, the posture of patient 102 may be constantly changing (e.g., patient 102 is in each of a plurality of postures for the transient amount of time). In such examples, system 100 may adjust sensing parameters to default sensing parameter values and / or pacing parameters to default pacing parameter values in response to a determination that the period of time between the current time and the determined change in posture is greater than or equal tothe maximum threshold time period. System 100 may determine whether the minimum threshold time period or the maximum threshold time period has been satisfied in accordance with the example processes previously described herein with respect to FIG. 4.

[0101] It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). In addition, while certain aspects of this disclosure are described as being performed by a single module, unit, or circuit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units, modules, or circuitry associated with, for example, a medical device.

[0102] In one or more examples, the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware -based processing unit. Computer-readable media may include non-transitory computer-readable media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer).

[0103] Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” or “processing circuitry” as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements.

[0104] In addition, it should be noted that system described herein may not be limited to treatment of a human patient. In alternative examples, the system may be implemented in non-human patient, e.g., primates, canines, equines, pigs, and felines. These otheranimals may undergo clinical or research therapies that may benefit from the subject matter of this disclosure.

[0105] The following examples are illustrative of the techniques described herein.

[0106] Example 1 : an implantable medical device (IMD) configured to be implanted in a patient, the IMD comprising: one or more medical therapy delivery elements; one or more sensors; memory; and processing circuitry configured to: receive sensed signals from the one or more sensors; determine, based on the received sensed signals, a posture of the patient; retrieve one or more therapy delivery parameter values stored in the memory, wherein the one or more therapy delivery parameter values correspond to the determined posture; determine that the one or more therapy delivery parameter values for the determined posture were configured within a threshold period of time from a current time; and in response to determining that the one or more therapy delivery parameter values were configured within the threshold period of time, cause the one or more medical therapy delivery elements to deliver medical therapy to the patient based on the one or more therapy delivery parameter values.

[0107] Example 2 : the IMD of example 1, wherein the processing circuitry is configured to: determine that none of a plurality of therapy delivery parameter values stored in the memory corresponds to the determined posture; in response to determining that none of the plurality of therapy delivery parameter values correspond to the determined posture, retrieve one or more default therapy delivery parameter values stored in the memory; and cause the one or more medical therapy delivery elements to deliver the medical therapy to the patient based on the one or more default therapy delivery parameter values.

[0108] Example 3 : the IMD of any of examples 1 and 2, wherein the processing circuitry is configured to: determine that the one or more therapy delivery parameter values were not configured within the threshold period of time; in response to determining that the one or more therapy delivery parameter values were not configured within the threshold period of time, determine one or more updated therapy delivery parameter values while the patient is in the determined posture; and store the one or more updated therapy delivery parameter values and corresponding data in the memory, wherein the corresponding data comprises, for each of the one or more updated therapy deliveryparameter values, a corresponding posture and a time when the processing circuitry determined the respective updated therapy delivery parameter value.

[0109] Example 4 : the IMD of example 3, wherein the processing circuitry is configured to cause the one or more medical therapy delivery elements to deliver the medical therapy to the patient based on the one or more therapy delivery parameter values until the processing circuitry has determined the one or more updated therapy delivery parameter values.

[0110] Example 5 : the IMD of any of examples 3 or 4, wherein the processing circuitry is configured to: in response to determining the one or more updated therapy delivery parameter values, cause the one or more medical therapy delivery elements to deliver the medical therapy to the patient based on the one or more updated therapy delivery parameter values.

[0111] Example 6 : the IMD of any of examples 3-5, wherein to determine the one or more updated therapy delivery parameter values, the processing circuity is configured to: generate one or more test therapy delivery parameter values; cause the one or more medical therapy delivery elements deliver the medical therapy to the patient based on the one or more test therapy delivery parameter values while the patient is in the determined posture; determine that the delivered medical therapy satisfies a threshold condition; and in response to determining that the delivered medical therapy satisfies the threshold condition, select the one or more updated therapy delivery parameter values based on the one or more test therapy delivery parameter values.

[0112] Example 7 : the IMD of example 6, wherein the medical therapy comprises a cardiac pacing therapy, and wherein to determine that the delivered medical therapy satisfies the threshold condition, the processing circuitry is configured to determine that the cardiac pacing therapy captures cardiac tissue of the patient.

[0113] Example 8 : the IMD of any of examples 3-7, further comprising communications circuitry coupled to the processing circuitry, and wherein the processing circuitry is configured to: prior to determining the one or more updated therapy delivery parameter values, cause the communications circuitry to output an alert to one or more external devices, the alert indicating that the IMD is delivering the medical therapy to the patient.

[0114] Example 9 : the IMD of any of examples 1-8, wherein the determined posture comprises a first posture, wherein the one or more therapy delivery parameter values comprises one or more first therapy delivery parameter values, and wherein the processing circuitry is configured to: determine, based on the received sensed signals, movement by the patient from the first posture to a second posture, the second posture being different from the first posture; retrieve, from the memory, one or more second therapy delivery parameter values corresponding to the second posture; determine that the processing circuitry determined the one or more second therapy delivery parameter values for the determined posture within the threshold period of time; and in response to determining that the processing circuitry determined the one or more second therapy delivery parameter values within the threshold period of time, cause the one or more medical therapy delivery elements to deliver medical therapy to the patient based on the one or more second therapy delivery parameter values while the patient is in the second posture.

[0115] Example 10: the IMD of any of examples 1-9, wherein the processing circuitry is configured to: determine, based on the received sensed signals, a change in one or more sensed signals while the patient remains in a same posture; based on the determined change in the one or more sensed signals, determine one or more updated therapy delivery parameter values while the patient is in the determined posture; and store the one or more updated therapy delivery parameter values and corresponding data in the memory, wherein the corresponding data comprises, for each of the one or more updated therapy delivery parameter values, a corresponding posture and a time when the processing circuitry determined the respective updated therapy delivery parameter value.

[0116] Example 11: the IMD of any of examples 1-10, wherein the one or more sensors comprises an accelerometer.

[0117] Example 12: the IMD of any of examples 1-11, wherein the medical therapy comprises a cardiac pacing therapy, and wherein the one or more medical therapy delivery elements comprises therapy delivery circuitry configured to deliver the cardiac pacing therapy via one or more electrodes.

[0118] Example 13: the IMD of example 12, wherein the one or more electrodes are configured to be implanted outside of a heart of a patient.

[0119] Example 14; the IMD of any of examples 12 and 13, wherein the one or more therapy delivery parameter values comprises one or more pacing parameter values, andwherein each of the one or more pacing parameter values corresponds to at least one pacing parameter, the at least one pacing parameter comprises one or more of: a pacing amplitude; a pacing pulse width; a pacing frequency; or a pacing vector.

[0120] Example 15: the IMD of any of examples 1-14, wherein the threshold period of time comprises 24 hours.

[0121] Example 16: a method comprising: receiving, by processing circuitry of an implantable medical device (IMD) implanted within a patient and from one or more sensors of the IMD, sensed signals; determining, by the processing circuitry and based on the received sensed signals, a posture of the patient; retrieving, by the processing circuitry and from memory of the IMD, one or more therapy delivery parameter values corresponding to the determined posture; determining, by the processing circuitry, that the one or more therapy delivery parameter values were configured within a threshold period of time from a current time; and in response to determining that the one or more therapy delivery parameter values were configured within the threshold period of time, causing, by the processing circuitry, one or more medical therapy delivery elements of the IMD to deliver medical therapy to the patient based on the one or more therapy delivery parameter values.

[0122] Example 17: the method of example 16, further comprising: determining, by the processing circuitry, that none of a plurality of therapy delivery parameter values stored in the memory corresponds to the determined posture; in response to determining that none of the plurality of therapy delivery parameter values corresponds to the determined posture, retrieving, by the processing circuitry, one or more default therapy delivery parameter values stored in the memory; and causing, by the processing circuitry, the one or more medical therapy delivery elements to deliver medical therapy to the patient based on the one or more default therapy delivery parameter values.

[0123] Example 18: the method of any of examples 16 and 17, further comprising: determining, by the processing circuitry, that the one or more therapy delivery parameter values were not configured within the threshold period of time; in response to determining that the one or more therapy delivery parameter values were not configured within the threshold period of time, determining, by the processing circuitry, one or more updated therapy delivery parameter values while the patient is in the determined posture; and storing, by the processing circuitry, the one or more updated therapy delivery parametervalues and corresponding data in the memory, wherein the corresponding data comprises, for each of the one or more updated therapy delivery parameter values, a corresponding posture and a time when the processing circuitry determined the respective updated therapy delivery parameter value.

[0124] Example 19: the method of example 18, further comprising: causing, by the processing circuitry, the one or more medical therapy delivery elements to deliver the medical therapy to the patient based on the one or more therapy delivery parameter values until the processing circuitry determines the one or more updated therapy delivery parameter values.

[0125] Example 20: the method of any of examples 18 or 19, further comprising: in response to determining the one or more updated therapy delivery parameter values, causing, by the processing circuitry, the one or more medical therapy delivery elements to deliver the medical therapy to the patient based on the one or more updated therapy delivery parameter values.

[0126] Example 21: the method of any of examples 18-20, wherein determining the one or more updated therapy delivery parameter values comprises: generating, by the processing circuitry, one or more test therapy delivery parameter values; causing, by the processing circuitry, the one or more medical therapy delivery elements deliver the medical therapy to the patient based on the one or more test therapy delivery parameter values; determining, by the processing circuitry, that the delivered medical therapy satisfies a threshold condition; and in response to determining that the delivered medical therapy satisfies the threshold condition, selecting, by the processing circuitry, one or more updated therapy delivery parameter values based on the one or more test therapy delivery parameter values.

[0127] Example 22: the method of example 21, wherein the medical therapy comprises a cardiac pacing therapy, and wherein determining that the delivery medical therapy satisfies the threshold condition comprises: determining, by the processing circuitry, that the cardiac pacing therapy captures cardiac tissue of the patient.

[0128] Example 23: the method of any of examples 18-22, further comprising: prior to determining the one or more updated therapy delivery parameter values, causing, by the processing circuitry, communications circuitry of the IMD to output an alert to one ormore external devices, wherein the alert indicates that the IMD is delivering the medical therapy to the patient.

[0129] Example 24: the method of any of examples 16-23, wherein the determined posture comprises a first posture, wherein the one or more therapy delivery parameter values comprises one or more first therapy delivery parameter values, and wherein the method further comprises: determining, by the processing circuitry and based on the received sensed signals, movement by the patient from the first posture to a second posture, the second posture being different from the first posture; retrieving, by the processing circuitry, one or more second therapy delivery parameter values corresponding to the second posture; determining, by the processing circuitry, that the one or more second therapy delivery parameter values were configured within the threshold period of time; and in response to determining that the processing circuitry determined the one or more second therapy delivery parameter values within the threshold period of time, causing, by the processing circuitry, the one or more medical therapy delivery elements to deliver medical therapy to the patient based on the one or more second therapy delivery parameter values.

[0130] Example 25: the method of any of examples 16-24, further comprising: determining, by the processing circuitry and based on the received sensed signals, a change in one or more sensed signals while the patient remains in a same posture; based on the determined change in the one or more sensed signals, determining, by the processing circuitry, one or more therapy delivery parameter values while the patient is in the determined posture; and storing, by the processing circuitry, the one or more updated therapy delivery parameter values and corresponding data in the memory, wherein the corresponding data comprises, for each of the one or more updated therapy delivery parameter values, a corresponding posture and a time when the processing circuitry determined the respective updated therapy delivery parameter value.

[0131] Example 26: the method of any of examples 16-25, wherein the one or more sensors comprises an accelerometer.

[0132] Example 27: the method of any of examples 16-26, wherein the medical therapy comprises a cardiac pacing therapy, and wherein the one or more medical therapy delivery elements comprises therapy delivery circuitry configured to deliver the cardiac pacing therapy via one or more electrodes.

[0133] Example 28: the method of example 27, wherein the one or more therapy delivery parameter values comprises one or more pacing parameter values, and wherein each of the one or more pacing parameter values corresponds to at least one pacing parameter, the at least one pacing parameter comprises one or more of: a pacing amplitude; a pacing pulse width; a pacing frequency; or a pacing vector.

[0134] Example 29: the method of any of examples 16 - 28, wherein the threshold period of time comprises 24 hours.

[0135] Example 30: an implantable medical device (IMD) configured to be implanted in a patient, the IMD comprising: sensing circuitry coupled to one or more electrodes; therapy delivery circuitry coupled to the one or more electrodes; one or more sensors; memory; and processing circuitry configured to: receive sensed signals from the one or more sensors; determine, based on the received sensed signals, a posture of the patient; retrieve, from the memory, one or more sensing parameter values for one or more sensing parameters, the one or more sensing parameter values corresponding to the determined posture; cause the sensing circuitry to sense electrical signals from the patient via the one or more electrodes based on the one or more retrieved sensing parameter values; in response to a determination that the sensed electrical signals satisfy a threshold condition, deliver cardiac pacing therapy to the patient, wherein to deliver the cardiac pacing therapy, the processing circuitry is configured to: retrieve one or more pacing parameter values stored in the memory, wherein the one or more pacing parameter values correspond to the determined posture; determine that the one or more pacing parameter values for the determined posture were configured within a threshold period of time from a current time; and in response to determining that the one or more pacing parameter values were configured within the threshold period of time, control the therapy delivery circuitry to deliver the cardiac pacing therapy to the patient via the one or more electrodes based on the one or more pacing parameter values.

[0136] Example 31: the IMD of example 30, wherein the threshold condition corresponds to an onset of one or more types of arrhythmia.

[0137] Example 32: the IMD of any of examples 30 and 31, wherein the processing circuitry is configured to: determine that none of a plurality of pacing parameter values stored in the memory correspond to the determined posture; in response to determining that none of the plurality of pacing parameter values correspond to the determined posture,retrieve one or more default pacing parameter values stored in the memory; and control the therapy delivery circuitry to deliver the cardiac pacing therapy to the patient via the one or more electrodes and based on the one or more default pacing parameter values.

[0138] Example 33: the IMD of any of examples 30-32, wherein the processing circuitry is configured to: determine that the one or pacing parameter values were not configured within the threshold period of time; in response to determining that the one or more pacing parameter values were not configured within the threshold period of time, determine one or more updated pacing parameter values while the patient is in the determined posture; store the one or more updated pacing parameter values and corresponding data in the memory, wherein the corresponding data comprises, for each of the one or more pacing parameter values, a corresponding posture and a time when the processing circuitry determined the respective updated pacing parameter value; and control the therapy delivery circuitry to deliver the cardiac pacing therapy to the patient via the one or more electrodes and based on the one or more updated pacing parameter values.

[0139] Example 34: the IMD of example 33, wherein the processing circuitry is configured to control the therapy delivery circuitry to deliver the cardiac pacing therapy to the patient based on the one or more pacing parameter values until the processing circuitry has determined the one or more updated pacing parameter values.

[0140] Example 35: the IMD of any of examples 33 or 34, wherein to determine the one or more updated pacing parameter values, the processing circuity is configured to: generate one or more test pacing parameter values; cause the one or more electrodes to deliver the cardiac pacing therapy to the patient based on the one or more test pacing parameter values while the patient is in the determined posture; determine that the delivered cardiac pacing therapy satisfies a threshold condition; and in response to determining that the delivered cardiac pacing therapy satisfies the threshold condition, select the one or more updated pacing parameter values based on the one or more test pacing parameter values.

[0141] Example 36: the IMD of example 35, wherein to determine that the delivered cardiac pacing therapy satisfies the threshold condition, the processing circuitry is configured to determine that the cardiac pacing therapy captures cardiac tissue of the patient when the patient is in the determined posture.

[0142] Example 37: the IMD of any of examples 30-36, wherein the determined posture comprises a first posture, wherein one or more sensing parameter values comprises one or more first sensing parameter values, wherein the one or more pacing parameter values comprises one or more first pacing parameter values, wherein the electrical signals comprise first electrical signals, and wherein the processing circuitry is configured to: determine, based on the received sensed signals, a change in the patient from the first posture to a second posture, the second posture being different from the first posture; retrieve, from the memory, one or more second sensing parameter values corresponding to the second posture; cause the one or more electrodes to sense second electrical signals from the patient based on the one or more retrieved second sensing parameter values; retrieve, from the memory, one or more second pacing parameter values corresponding to the second posture; determine that the one or more second pacing parameter values are configured within the threshold period of time; and in response to determining that the one or more second pacing parameter values are configured within the threshold period of time, control the therapy delivery circuitry to deliver the cardiac pacing therapy to the patient via the one or more electrodes and based on the one or more second pacing parameter values while the patient is in the second posture.

[0143] Example 38: the IMD of any of examples 30-37, wherein the one or more sensors comprises an accelerometer.

[0144] Example 39: the IMD of any of examples 30-38, wherein the one or more electrodes are implanted outside of a heart of a patient.

[0145] Example 40: the IMD of any of examples 30-39, wherein the one or more pacing parameter values correspond to one or more pacing parameters, the one or more pacing parameters comprising one or more of: a pacing amplitude; a pacing pulse width; a pacing frequency; or a pacing vector.

[0146] Example 41: the IMD of any of examples 30-40, wherein the threshold period of time comprises 24 hours.

[0147] Example 42: an implantable medical device (IMD) configured to be implanted in a patient, the IMD comprising: a sensing element coupled to tissue of the patient; one or more sensors; memory; and processing circuitry configured to: receive sensed signals from the one or more sensors; determine, based on the received sensed signals, a posture of the patient; andin response to the determined posture, cause the sensing element to sense electrical signals from the tissue based on one or more sensing parameter values stored in the memory, wherein the one or more sensing parameter values correspond to the determined posture.

[0148] Example 43: the IMD of example 42, wherein the processing circuitry is configured to: determine that none of a plurality of sensing parameter values stored in the memory corresponds to the determined posture; and in response to determining that none of the plurality of sensing parameter values correspond to the determined posture, cause the sensing element to deliver the medical therapy to the patient based on one or more default sensing parameter values stored in the memory.

[0149] Example 44: the IMD of any of examples 42 and 43, wherein the determined posture comprises a first posture, wherein the one or more sensing parameter values comprises one or more first sensing parameter values, and wherein the processing circuitry is configured to: determine, based on the received sensed signals, movement by the patient from the first posture to a second posture, the second posture being different from the first posture; and retrieve, from the memory, one or more second sensing parameter values corresponding to the second posture; and in response to determining that the patient is in the second posture, cause the one or more sensing elements to sense the electrical signals from the tissue based on one or more second sensing parameter values stored in the memory, wherein the one or more second sensing parameter values correspond to the second posture.

[0150] Example 45: the IMD of any of examples 42-44, wherein the one or more sensors comprises an accelerometer.

[0151] Example 46: the IMD of any of examples 42-45, wherein the sensing element comprises sensing circuitry configured to sense the electrical signal via one or more electrodes.

[0152] Example 47: the IMD of example 46, wherein the one or more electrodes are implanted outside of a heart of a patient.

[0153] Example 48: the IMD of any of examples 42-47, wherein the one or more sensing parameter values comprises one or more of: a sensing threshold value; a threshold timing value; a sensing sensitivity value; or a sensing vector.

[0154] Example 49: the IMD of any of examples 42-48, wherein the memory is configured to store one or more sensing templates, wherein each sensing template of theone or more sensing templates corresponds to a different posture of the patient, wherein cause the sensing element to sense the electrical signals from the tissue based on the one or more sensing parameter values, the processing circuitry is configured to: retrieve a sensing template of the one or more sensing templates from the memory, wherein the sensing template corresponds to the determined posture, and wherein the sensing template is defined by the one or more sensing parameter values; and apply the sensing template to cause the sensing element to sense the electrical signals based on the one or more sensing parameter values.

[0155] Example 50: the IMD of example 49, wherein the electrical signals comprises cardiac signals, and wherein at least one sensing template of the one or more sensing templates includes an electrogram (EGM) morphology sensing algorithm.

[0156] Example 51: the IMD of example 50, wherein the EGM morphology sensing algorithm comprises a wavelet morphology sensing algorithm.

[0157] Example 52: the IMD of any of examples 49-51, wherein to apply the sensing template to cause the sensing element to sense the electrical signals based on the one or more sensing parameter values, the processing circuitry is configured to: determine whether the sensing template has been generated, verified, or updated within a threshold period of time prior to a current time; in response to determining that the sensing template has been generated, verified, or updated within the threshold period of time, apply the sensing template; and in response to determine that the sensing template was not generated, verified, or updated within the threshold period of time, update at least one sensing parameter value of the one or more sensing parameter values.

[0158] Example 53: the IMD of example 52, wherein the threshold period of time comprises 24 hours.

[0159] It will be appreciated by persons skilled in the art that the present application is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the application, which is limited only by the following claims.

Claims

WHAT IS CLAIMED IS:

1. An implantable medical device (IMD) configured to be implanted in a patient, the IMD comprising: one or more medical therapy delivery elements; one or more sensors; memory; and processing circuitry configured to: receive sensed signals from the one or more sensors; determine, based on the received sensed signals, a posture of the patient; retrieve one or more therapy delivery parameter values stored in the memory, wherein the one or more therapy delivery parameter values correspond to the determined posture ; determine that the one or more therapy delivery parameter values for the determined posture were configured within a threshold period of time from a current time; and in response to determining that the one or more therapy delivery parameter values were configured within the threshold period of time, cause the one or more medical therapy delivery elements to deliver medical therapy to the patient based on the one or more therapy delivery parameter values.

2. The IMD of claim 1, wherein the processing circuitry is configured to: determine that none of a plurality of therapy delivery parameter values stored in the memory corresponds to the determined posture; in response to determining that none of the plurality of therapy delivery parameter values correspond to the determined posture, retrieve one or more default therapy delivery parameter values stored in the memory; and cause the one or more medical therapy delivery elements to deliver the medical therapy to the patient based on the one or more default therapy delivery parameter values.

3. The IMD of any of claims 1 and 2, wherein the processing circuitry is configured to: determine that the one or more therapy delivery parameter values were not configured within the threshold period of time; in response to determining that the one or more therapy delivery parameter values were not configured within the threshold period of time, determine one or more updated therapy delivery parameter values while the patient is in the determined posture; and store the one or more updated therapy delivery parameter values and corresponding data in the memory, wherein the corresponding data comprises, for each of the one or more updated therapy delivery parameter values, a corresponding posture and a time when the processing circuitry determined the respective updated therapy delivery parameter value.

4. The IMD of claim 3, wherein the processing circuitry is configured to cause the one or more medical therapy delivery elements to deliver the medical therapy to the patient based on the one or more therapy delivery parameter values until the processing circuitry has determined the one or more updated therapy delivery parameter values.

5. The IMD of any of claims 3 or 4, wherein the processing circuitry is configured to: in response to determining the one or more updated therapy delivery parameter values, cause the one or more medical therapy delivery elements to deliver the medical therapy to the patient based on the one or more updated therapy delivery parameter values.

6. The IMD of any of claims 3-5, wherein to determine the one or more updated therapy delivery parameter values, the processing circuity is configured to: generate one or more test therapy delivery parameter values; cause the one or more medical therapy delivery elements deliver the medical therapy to the patient based on the one or more test therapy delivery parameter values while the patient is in the determined posture; determine that the delivered medical therapy satisfies a threshold condition; andin response to determining that the delivered medical therapy satisfies the threshold condition, select the one or more updated therapy delivery parameter values based on the one or more test therapy delivery parameter values.

7. The IMD of claim 6, wherein the medical therapy comprises a cardiac pacing therapy, and wherein to determine that the delivered medical therapy satisfies the threshold condition, the processing circuitry is configured to determine that the cardiac pacing therapy captures cardiac tissue of the patient.

8. The IMD of any of claims 3-7, further comprising communications circuitry coupled to the processing circuitry, and wherein the processing circuitry is configured to: prior to determining the one or more updated therapy delivery parameter values, cause the communications circuitry to output an alert to one or more external devices, the alert indicating that the IMD is delivering the medical therapy to the patient.

9. The IMD of any of claims 1-8, wherein the determined posture comprises a first posture, wherein the one or more therapy delivery parameter values comprises one or more first therapy delivery parameter values, and wherein the processing circuitry is configured to: determine, based on the received sensed signals, movement by the patient from the first posture to a second posture, the second posture being different from the first posture; retrieve, from the memory, one or more second therapy delivery parameter values corresponding to the second posture; determine that the processing circuitry determined the one or more second therapy delivery parameter values for the determined posture within the threshold period of time; and in response to determining that the processing circuitry determined the one or more second therapy delivery parameter values within the threshold period of time, cause the one or more medical therapy delivery elements to deliver medical therapy to the patient based on the one or more second therapy delivery parameter values while the patient is in the second posture.

10. The IMD of any of claims 1-9, wherein the processing circuitry is configured to: determine, based on the received sensed signals, a change in one or more sensed signals while the patient remains in a same posture; based on the determined change in the one or more sensed signals, determine one or more updated therapy delivery parameter values while the patient is in the determined posture; and store the one or more updated therapy delivery parameter values and corresponding data in the memory, wherein the corresponding data comprises, for each of the one or more updated therapy delivery parameter values, a corresponding posture and a time when the processing circuitry determined the respective updated therapy delivery parameter value.

11. The IMD of any of claims 1-10, wherein the one or more sensors comprises an accelerometer.

12. The IMD of any of claims 1-11, wherein the medical therapy comprises a cardiac pacing therapy, and wherein the one or more medical therapy delivery elements comprises therapy delivery circuitry configured to deliver the cardiac pacing therapy via one or more electrodes.

13. The IMD of claim 12, wherein the one or more electrodes are configured to be implanted outside of a heart of a patient.

14. The IMD of any of claims 12 and 13, wherein the one or more therapy delivery parameter values comprises one or more pacing parameter values, and wherein each of the one or more pacing parameter values corresponds to at least one pacing parameter, the at least one pacing parameter comprises one or more of: a pacing amplitude; a pacing pulse width; a pacing frequency; or a pacing vector.

15. The IMD of any of claims 1-14, wherein the threshold period of time comprises 24 hours.

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