Electrode arrangement for curved medical device leads

Abstract

This disclosure relates to curved medical electrical leads. For example, the medical electrical lead includes a lead body and a high-voltage electrode located on the lead body, the high-voltage electrode including a proximal coated portion, a distal coated portion, and an uncoated portion. Furthermore, the medical electrical lead includes a first low-voltage electrode and a second low-voltage electrode distal to the first low-voltage electrode, wherein a first wire passes through the first and second low-voltage electrodes, wherein a second wire passes through the first low-voltage electrode and the uncoated portion, the second wire forming a first angle with the first wire, and wherein a third wire passes through the second low-voltage electrode and the uncoated portion, the third wire forming a second angle with the first wire.

Description

Technical Field

[0001] This disclosure generally relates to medical device systems, and more specifically, to cardiac sensing and therapy delivery via medical device systems. Background Technology

[0002] Some types of implantable medical device (IMD) systems, such as pacemakers or implantable cardioverter defibrillator systems, can be used to provide cardiac sensing and therapy to patients via one or more electrodes. Some IMDs include an implantable housing containing a closed pulse generator and other electronic components, which can be configured for subcutaneous implantation, for example, in a patient's chest. The IMD can be connected to one or more implantable medical leads containing one or more electrodes. The leads can be configured such that the electrodes can be implanted, for example, inside the heart, such as via a venous lead, or externally to the heart and vascular system, such as via an extravascular lead. Extravascular leads for such IMD systems can be configured such that electrodes positioned, for example, on the distal portion of the lead, are implanted subcutaneously, substernally, or in other extravascular locations. Summary of the Invention

[0003] Generally, this disclosure relates to apparatus, systems, and techniques for using medical device leads with an electrode arrangement that provides a set of electrode vectors for sensing electrical signals and / or delivering electrotherapy. For example, when used for sensing electrocardiogram (ECG) signals and / or delivering cardiac pacing, the vectors have different spatial positions and orientations relative to the heart. In some instances, the resting or implanted state of at least a portion of the medical device lead may be curved, positioning the electrodes such that at least two of the vectors in the set are not parallel. The non-parallel vectors enable a medical device coupled to the medical device lead to sense ECG signals from different angles relative to the heart, or to deliver electrotherapy from different angles relative to the heart.

[0004] Two points can be referenced to sense electrical signals. For example, a medical device can measure the voltage difference between two electrodes, thereby establishing a sensing electrode vector between the two electrodes. The ability to sense based on a set of vectors provided by the medical device leads configured according to the technology of this disclosure increases the likelihood that the medical device will be able to detect and process cardiac depolarization and other features of the electrocardiogram, for example, to determine the therapy to be delivered to the patient. Similarly, therapies delivered via different electrical therapy vectors may be differently able to capture target tissue, and the ability of the medical device to select from the set of vectors increases the likelihood of the therapy being effective and / or allows the selection of vectors that capture tissue with relatively low energy consumption.

[0005] Example medical device leads may include at least one defibrillation electrode. In some instances, the defibrillation electrode may be positioned along a curved portion of the medical device lead. The defibrillation electrode may include a proximal coated portion, a distal coated portion, and an uncoated portion located between the proximal and distal coated portions. The coated portions of the defibrillation electrode may be configured to allow the conduction of relatively high voltage signals and prevent the conduction of relatively low voltage signals. Thus, in some cases, the proximal and distal coated portions may be configured to conduct defibrillation pulses, prevent the transmission of pacing pulses, and prevent the sensing of cardiac depolarization. In some cases, the uncoated portion of the defibrillation electrode may be configured to conduct defibrillation pulses, conduct pacing pulses, and allow the sensing of cardiac depolarization. In this way, the uncoated portion of the defibrillation electrode may be configured to combine with other electrodes to form a vector for detecting cardiac depolarization and other cardiac electrical activity, and to form a cardiac pacing vector.

[0006] In some instances, the defibrillator electrode is positioned along a curved portion of the medical device lead, resulting in an arc-shaped electrode with the uncoated portion of the electrode located at the peak of the arc. Furthermore, in some cases, the first pacing / sensing electrode is positioned proximal to the medical device lead of the defibrillator electrode, while the second pacing / sensing electrode is positioned distal to it. Therefore, in instances where the defibrillator electrode is arc-shaped and the uncoated portion is located at the peak of the arc, the uncoated portion of the defibrillator electrode is displaced from the axis between the first and second pacing / sensing electrodes. Thus, the first pacing / sensing electrode, the second pacing / sensing electrode, and the uncoated portion of the defibrillator electrode can form three possible vectors: a first vector between the first and second pacing / sensing electrodes, a second vector extending between the first pacing / sensing electrode and the uncoated portion, and a third vector extending between the second pacing / sensing electrode and the uncoated portion.

[0007] The technology disclosed herein may provide one or more advantages. For example, straight or near-straight medical device leads, or wires of any shape with pacing / sensing electrodes located at or near a common axis, may only be able to sense cardiac depolarization based on a vector aligned with a single axis. In contrast, example leads with a curved shape may be configured with non-coaxial electrodes that are configured to form vectors that angle with each other. For example, a first line passing through a first pacing / sensing electrode and a second pacing / sensing electrode may form an angle with a second line passing through an uncoated portion of the first pacing / sensing electrode and a defibrillation electrode. The propagation of electrical signals during the cardiac cycle varies from patient to patient. For example, the position of the heart within the chest cavity may differ slightly from patient to patient, resulting in different directions of electrical depolarization. Therefore, providing the option to sense cardiac depolarization based on vectors of angular displacement relative to each other may be beneficial in order to increase the likelihood of accurately capturing and processing cardiac depolarization in a large number of patients.

[0008] Furthermore, including the uncoated portion of the defibrillator at the apex of the curve pattern of the defibrillator electrode, where the uncoated portion is relatively small compared to the size of the defibrillator electrode, can be beneficial. For example, by making the uncoated portion relatively small compared to the size of the defibrillator electrode, the IMD may be able to increase the length of the vector and increase the angle formed between the vectors. Moreover, using the uncoated portion of the defibrillator electrode to provide the set cardiac sensing and / or pacing vector, instead of adding a dedicated pacing / sensing electrode, allows the defibrillator electrode and the electrodes used for pacing and sensing to share the desired positioning along the medical lead relative to the heart, and avoids adding electrical conductors and connections associated with additional pacing / sensing electrodes to the lead. The proximal and distal coated portions of the defibrillator electrode can also reduce the amount of passive shunt occurring in the signal sensed by the medical device via the medical device lead.

[0009] In some examples, a medical electrical lead includes a lead body and a high-voltage electrode located on the lead body. The high-voltage electrode includes a proximal coated portion, a distal coated portion, and an uncoated portion located between the proximal and distal coated portions. The proximal and distal coated portions are coated with an electrically insulating material configured to prevent the conduction of a signal with a first voltage range between the high-voltage electrode and patient tissue, and to allow the conduction of a signal with a second voltage range between the high-voltage electrode and patient tissue, wherein the first voltage range is lower than the second voltage range. Furthermore, the medical electrical lead includes a low-voltage electrode assembly located on the lead body. This low-voltage electrode assembly includes a first low-voltage electrode and a second low-voltage electrode distal to the first low-voltage electrode. The low-voltage electrode assembly and the uncoated portion are located on the lead body such that a first angle is formed between a first wire passing through the first and second low-voltage electrodes and a second wire passing through the first low-voltage electrode and the uncoated portion, and a second angle is formed between the first wire and a third wire passing through the second low-voltage electrode and the uncoated portion.

[0010] In some instances, a medical device system includes an electrical lead comprising a lead body and a high-voltage electrode located on the lead body. The high-voltage electrode includes a proximal coated portion, a distal coated portion, and an uncoated portion located between the proximal and distal coated portions. The proximal and distal coated portions are coated with an electrically insulating material configured to prevent the conduction of a signal having a first voltage range between the high-voltage electrode and patient tissue, and to allow the conduction of a signal having a second voltage range between the high-voltage electrode and patient tissue, wherein the first voltage range is lower than the second voltage range. Furthermore, the medical device system includes a low-voltage electrode assembly located on the lead body, comprising a first low-voltage electrode and a second low-voltage electrode distal to the first low-voltage electrode. The low-voltage electrode assembly and the uncoated portion are located on the lead body such that a first angle is formed between a first wire passing through the first and second low-voltage electrodes and a second wire passing through the first low-voltage electrode and the uncoated portion, and a second angle is formed between the first wire and a third wire passing through the second low-voltage electrode and the uncoated portion. Additionally, the medical device system includes a medical device comprising a sensing circuit electrically coupled to a medical electrical lead, wherein the sensing circuit is configured to: sense a first electrical map based on a first vector including a first low-voltage electrode and a second low-voltage electrode; sense a second electrical map based on a second vector including a first low-voltage electrode and an uncoated portion; or sense a third electrical map based on a third vector including a second low-voltage electrode and an uncoated portion.

[0011] In some instances, a medical electrical lead includes a lead body comprising a first curved portion and a second curved portion distal to the first curved portion; a first high-voltage electrode located on the first curved portion of the lead body, wherein the first high-voltage electrode includes at least one coated portion coated with an electrically insulating material configured to prevent conduction of a signal having a first voltage range between the first high-voltage electrode and patient tissue, and to allow conduction of a signal having a second voltage range between the first high-voltage electrode and patient tissue, wherein the first voltage range is lower than the second voltage range; a second high-voltage electrode located on the second curved portion of the lead body; and a low-voltage electrode assembly located on the lead body, the low-voltage electrode assembly including a first low-voltage electrode and a second low-voltage electrode distal to the first low-voltage electrode, wherein the first low-voltage electrode is located on the lead body proximal to the first high-voltage electrode, and wherein the second low-voltage electrode is located on the lead body between the first high-voltage electrode and the second high-voltage electrode.

[0012] 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, apparatus, and methods described in detail in the following drawings and specification. Further details of one or more embodiments of this disclosure are set forth in the following drawings and specification. Other features, objectives, and advantages will become apparent from the description, drawings, and claims. Attached Figure Description

[0013] Figure 1A The present invention is a conceptual diagram showing a front view of a patient with an example medical device system having medical leads, based on one or more techniques described herein.

[0014] Figure 1B It demonstrates, based on one or more techniques described herein, that have Figure 1A A conceptual diagram of a patient's side view of an example medical device system.

[0015] Figure 1C It demonstrates, based on one or more techniques described herein, that have Figure 1A A conceptual diagram of a patient's cross-sectional view of an example medical device system.

[0016] Figure 2 This is a demonstration based on one or more technologies described in this article. Figure 1A -1C Functional block diagram of an example configuration of an implantable medical device (IMD).

[0017] Figure 3 This is a demonstration based on one or more technologies described in this article. Figure 1A A block diagram illustrating an example configuration of components for an external device.

[0018] Figure 4A It is based on one or more technologies described herein. Figure 1A Front view of the distal portion of the medical lead in -1C.

[0019] Figure 4B The demonstration of one or more technologies described herein can be seen from Figure 4A A conceptual diagram of the vector obtained from the distal portion of the medical lead.

[0020] Figure 5A It is based on one or more technologies described herein. Figure 4A A side view of the distal portion of a medical lead.

[0021] Figure 5B This is a side view of the distal portion of another example medical lead according to one or more techniques described herein.

[0022] Figure 6This is a flowchart illustrating an example operation of sensing electrical signals according to one or more techniques of this disclosure.

[0023] Throughout the specification and drawings, the same reference numerals denote the same elements. Detailed Implementation

[0024] This disclosure describes techniques for using medical device leads with an electrode arrangement providing non-parallel electrode vector groups. In some cases, the medical device lead may include an electrode group comprising at least one defibrillator electrode and at least two pacing / sensing electrodes. The medical device lead may include at least one curved portion such that the vector groups form an angle with each other. In some instances, the defibrillator electrode may be positioned along the curved portion of the medical device lead such that the defibrillator electrode forms an arc, and may include an uncoated portion at or near the peak or apex of the arc, the uncoated portion being configured to conduct relatively low voltage signals, such as cardiac pacing pulses and sensed electrical signals from the heart, thereby forming a vector with the pacing / sensing electrodes for pacing and sensing. In some instances, the uncoated portions of the first pacing / sensing electrode, the second pacing / sensing electrode, and the defibrillator electrode may form a triangle. In some instances, the defibrillator electrode may be referred to herein as a "high-voltage electrode." In some instances, the pacing / sensing electrode may be referred to herein as a "low-voltage electrode."

[0025] Figure 1A-1C This is a concept diagram of a medical device system 10 implanted in the patient's body 8. Figure 1A This is a front view of the medical device system 10 implanted in the patient 8. Figure 1B This is a side view of the medical device system 10 implanted in the patient 8. Figure 1C This is a horizontal view of the medical device system 10 implanted in the patient 8.

[0026] In some instances, medical device system 10 is an extravascular implantable cardioverter-defibrillator (EV-ICD) system implanted in a patient 8. However, the techniques described herein are applicable to other implantable and / or external cardiac systems, including pacemaker systems, cardiac resynchronization therapy defibrillator (CRT-D) systems, cardioverter-defibrillator systems, wearable automated external defibrillator (WAED) systems, or combinations thereof, and other stimulation and / or sensing systems, such as neurostimulation systems. Furthermore, system 10 may not be limited to the treatment of human patients. In alternative instances, system 10 may be implemented in non-human patients (e.g., primates, dogs, horses, pigs, cattle, sheep, cats, etc.). These other animals may undergo clinical or research therapies that may benefit from the subject matter of this disclosure.

[0027] The IMD 12 is configured for implantation in a patient (e.g., patient 8). In some instances, the IMD 12 is implanted subcutaneously or submuscularly in the middle of the left axilla of patient 8, allowing the IMD 12 to be positioned above the left thoracic rim of patient 8. In other instances, the IMD 12 may be implanted in other subcutaneous locations on patient 8, such as in the chest or abdomen. The IMD 12 includes a housing 20 that can form a hermetically sealed protective layer for the IMD 12 assembly. In some instances, the housing 20 of the IMD 12 may be formed of a conductive material such as titanium or a combination of conductive and non-conductive materials that can be used as housing electrodes. The IMD 12 may also include a connector assembly (also referred to as a connector block or plug) containing an electrical feedthrough through which an electrical connection is made between a lead 22 and electronic components contained within the housing. The housing 20 may house one or more of a processing circuitry, memory, transmitter, receiver, sensor, sensing circuitry, therapeutic circuitry, power supply, and other suitable components.

[0028] Typically, a medical device system (e.g., system 10) may include one or more medical devices, leads, external devices, or other components configured to implement the techniques described herein. Figure 1A In the example shown, IMD 12 is connected to an implantable cardiac lead 22. In other examples, two or more leads may be connected to IMD 12. In some examples, IMD 12 may be configured to deliver a high-energy anti-tachyarrhythmia (e.g., cardioversion or defibrillation) shock to heart 18 upon detection of a ventricular tachyarrhythmia (e.g., ventricular tachycardia (VT) or ventricular fibrillation (VF)). Cardioversion shocks are typically delivered synchronously with a detected R wave when fibrillation detection criteria are met. Defibrillation shocks are typically delivered when fibrillation criteria are met and an R wave cannot be discerned from the signal sensed by IMD 12.

[0029] Lead 22 comprises an elongated lead body having a proximal end and a distal portion, the proximal end including a connector 30 configured to connect to IMD 12, and the distal portion including electrodes 32A, 32B, 36A, and 36B (generally, "electrodes 32, 36"). Lead 22 extends subcutaneously above the thorax towards the center of the trunk of patient 8 from IMD 12. At a location near the center of the trunk, lead 22 bends or turns and extends upward within the pleural cavity behind sternum 24. Thus, lead 22 can be at least partially implanted in the substernal space, such as at a target location between the thorax or sternum 24 and heart 18. In one such configuration, the proximal portion of lead 22 can be configured to extend subcutaneously towards sternum 24 from IMD 12, and the distal portion of lead 22 can be configured to extend upward within the anterior mediastinum 26 behind sternum 24. Figure 1CLead 22 may include one or more curved segments as discussed herein to configure lead 22 to extend naturally (e.g., in a self-biased manner) when unfolded.

[0030] For example, the lead 22 may extend upward within the pleural cavity, posterior to the sternum 24, within the anterior mediastinum 26. The anterior mediastinum 26 can be considered as being defined posteriorly by the pericardium 16, laterally by the pleura 28, and anteriorly by the sternum 24. In some instances, the anterior wall of the anterior mediastinum 26 may also be formed by the transverse sternotomy muscle and one or more costal cartilages. The anterior mediastinum 26 contains a number of loose connective tissues (such as celluloid), some lymphatic vessels, lymph nodes, substernal muscle tissue (e.g., the transverse sternotomy muscle), and small blood vessels or vascular branches. In one instance, the distal portion of the lead 22 may be substantially implanted within the loose connective tissue and / or substernal muscle tissue of the anterior mediastinum 26. In such instances, the distal portion of the lead 22 may be physically isolated from the pericardium 16 of the heart 18. The lead substantially implanted within the anterior mediastinum 26 may be referred to herein as a substernal lead. Electrical therapy (such as antiarrhythmic pacing, cardioversion, or defibrillation) provided by a lead 22 that is substantially implanted within the anterior mediastinum 26 may be referred to herein as substernal electrical therapy, substernal pacing, substernal cardioversion, or substernal defibrillation.

[0031] The distal portion of lead 22 is described herein as being substantially implanted within the anterior mediastinum 26. Thus, some of the distal portion of lead 22 may extend beyond the anterior mediastinum 26 (e.g., the proximal end of the distal portion), but the majority of the distal portion may be located within the anterior mediastinum 26. In other instances, the distal portion of lead 22 may be implanted intrathoracically at other nonvascular extrapericardial locations, encompassing the periphery of other portions of the pericardium 16 or heart 18 and adjacent to but not attached to said pericardium or other portions and not above the sternum 24 or thorax, in spaces, tissues, or other anatomical features. Thus, lead 22 may be implanted at any location within the “infrasternal space” defined by the lower surface between the sternum and / or thorax and the body cavity, but excluding other portions of the pericardium 16 or heart 18. The infrasternal space may alternatively be referred to by the terms “retrosternal space” or “mediastinum” or “infrasternal,” and may include the anterior mediastinum 26. In other words, the distal portion of lead 22 can be implanted in the area surrounding the outer surface of the heart 18, but not attached to the heart 18. For example, the distal portion of lead 22 can be physically isolated from the pericardium 16.

[0032] Lead 22 may include an insulated lead body having a proximal end and a distal portion, the proximal end including a connector 30 configured to connect to IMD 12, and the distal portion including one or more electrodes. Figure 1AAs shown, one or more electrodes of lead 22 may include electrodes 32A, 32B, 36A, and 36B, but in other instances, lead 22 may include more or fewer electrodes. Lead 22 also includes one or more conductors that form conductive paths within the lead body and interconnect electrical connectors to corresponding electrodes in the electrodes. In some cases, lead 22 includes a first conductor electrically coupled to defibrillation electrode 32A, a second conductor electrically coupled to defibrillation electrode 32B, a third conductor electrically coupled to pacing / sensing electrode 36A, and a fourth conductor 36B electrically coupled to pacing / sensing electrode 36B. In some instances, the proximal ends of the first, second, third, and fourth conductors may be coupled via interconnections in connector 30 to sensing circuitry and / or signal generation circuitry within housing 20 of IMD 12.

[0033] Electrodes 32A and 32B may be defibrillation electrodes (individually or jointly, “one or more defibrillation electrodes 32”). Although electrode 32 may be referred to herein as “defibrillation electrode 32”, electrode 32 may be configured to deliver other types of anti-tachyarrhythmic shocks, such as cardioversion shocks. In some instances, defibrillation electrodes 32A and 32B may functionally be different segments of a single defibrillation electrode 32, such that both defibrillation electrodes 32 are coupled to the same conductor, or otherwise configured to provide the same electrical therapy. Furthermore, in some instances, defibrillation electrodes 32A and 32B may each be coupled to different conductors. In such instances, defibrillation electrodes 32A and 32B may be configured to provide electrical therapy together or individually via a switch within IMD 12. Although defibrillation electrodes 32 are… Figure 1A-1C The defibrillator 32 is depicted as a coil electrode, but it should be understood that the defibrillator 32 may be configured otherwise in other instances. The defibrillator 32 may be positioned on the distal portion of the lead 22, wherein the distal portion of the lead 22 is the portion of the lead 22 configured to be implanted to extend along the sternum 24.

[0034] In some cases, the defibrillator electrode 32 may include one or more portions coated with an electrically insulating material. A defibrillator electrode portion coated with at least one electrically insulating material may be referred to herein as a "coated portion". Furthermore, in some cases, the defibrillator electrode 32 may each include one or more portions not coated with an electrically insulating material. A defibrillator electrode portion not coated with an electrically insulating material may be referred to herein as an "uncoated portion". In some cases, the entire surface area of ​​the defibrillator electrode 32 may be coated. In some cases, the entire surface area of ​​the defibrillator electrode 32 may be uncoated.

[0035] exist Figure 1AIn the example shown in –1C, defibrillator electrode 32A includes a proximal coated portion 33A, a distal coated portion 33B, and an uncoated portion 34 located between the proximal coated portion 33A and the distal coated portion 33B. In some examples, the uncoated portion 34 is a first uncoated portion, the proximal coated portion 33A is a first proximal uncoated portion, and the distal coated portion 33B is a first distal uncoated portion. In some such examples, defibrillator electrode 32B includes a second proximal coated portion, a second distal coated portion, and a second uncoated portion located between the second proximal coated portion and the second distal coated portion. However, in other examples, one of defibrillator electrodes 32A or 32B may not include any coated portion and may be completely uncoated, or may not include any uncoated portion and may be completely coated. In another example, either defibrillator electrode 32A or 32B may not include either a coated portion or an uncoated portion. Conversely, one defibrillator electrode 32 (e.g., defibrillator electrode 32A) may be fully coated, while another defibrillator electrode 32 (e.g., defibrillator electrode 32B) may be completely uncoated. For each defibrillator electrode 32, the "proximal" coated portion may be more proximal to the lead 22 (e.g., more proximal to the connector 30) than the "distal" coated portion.

[0036] In some instances, the electrically insulating material coating the proximal coating portion 33A and the distal coating portion 33B (collectively referred to as "coating portion 33") prevents the conduction of relatively low voltage signals between the coating portion 33 and the tissue of the patient 8. Alternatively, the electrically insulating material may allow the conduction of relatively high voltage signals between the coating portion 33 and the tissue of the patient 8. The uncoated portion 34 may be configured to allow the conduction of both relatively low and relatively high voltage signals. For example, the coating portion 33 may be configured to prevent the transmission of pacing pulses, prevent the sensing of cardiac depolarization, and allow the transmission of a defibrillation shock. On the other hand, the uncoated portion 34 may be configured to transmit a defibrillation shock, transmit pacing pulses, sense electrical signals corresponding to cardiac depolarization, or any combination thereof. Thus, the entire length of a defibrillation electrode, such as defibrillation electrode 32A, may be configured to conduct a defibrillation shock transmitted by the signal generation circuitry within the housing 20, and a portion of defibrillation electrode 32A (e.g., the uncoated portion 34) may be configured to transmit pacing pulses and sense cardiac depolarization or other relatively low voltage electrical signals. In this way, the uncoated portion 34 of the defibrillator electrode 32 can perform at least some of the same functions as the pacing / sensing electrode 36. In some cases, the coated portion 33 can prevent or reduce the degree of passive shunting of the electrode 32 during ECG sensing by the IMD 12 via other electrodes (e.g., electrode 36) through the lead 22.

[0037] In some instances, the electrically insulating material may extend around the entire circumference of the coated portion 33 of the defibrillator electrode 32. The electrically insulating material can be any of a variety of materials, such as a single or combination of the following: tantalum pentoxide, titanium oxide, zirconium oxide, vanadium oxide, niobium oxide, doped silicon, silicon dioxide, boron-doped diamond, doped glass, ceramic coatings, or polymer composites, or other materials having the property of substantially preventing the transmission or conduction of low voltages while substantially not preventing the transmission or conduction of high voltages. The thickness of the electrically insulating material may vary based on the type of material used to fabricate the defibrillator electrode 32, the type of electrically insulating material, the size of the corresponding coated portion 33, and the intended depth and location of the distal portion of the lead 22, such as a substernal or subcutaneous location. In instances where tantalum pentoxide is the electrically insulating material, the thickness of the electrically insulating material may range from 0.2 micrometers (μm) to less than or equal to 2.0 μm. However, other thicknesses may be used without departing from the scope of this disclosure. In one instance, the coated portion 33 is coated with tantalum pentoxide with a thickness ranging from 0.6 μm to 0.9 μm. In such instances, the tantalum pentoxide coating significantly impedes the flow of current up to 90V, thereby preventing the sensing of cardiac depolarization events and blocking the transmission of pacing pulses. Furthermore, in such instances, electrical signals with voltages exceeding 90V (e.g., defibrillation shock) overcome the electrical insulation properties of the tantalum pentoxide coating and can be conducted through the coated portion 33 of the defibrillation electrode 32.

[0038] The dimensions of the coated portion 33 and the uncoated portion 34 may differ. In some instances, the uncoated portion 34 may be less than or equal to 25% of the length of the defibrillator electrode 32A. Additionally, in some instances, the uncoated portion 34 may be less than or equal to 10% of the length of the defibrillator electrode 32A. In some instances, the uncoated portion 34 may have a size less than or equal to 100 square millimeters (mm²). 2 The surface area of ​​the uncoated portion 34 may be less than or equal to 10 mm. 2 The surface area. Uncoated and coated portions may have dimensions different from those mentioned above.

[0039] Lead 22 can be implanted at a target site behind the sternum 24 such that the therapeutic electrode vector substantially crosses the ventricle of the heart 18, substantially crosses the atrium of the heart 18, or substantially crosses both the ventricle and atrium of the heart 18. In some instances, the therapeutic vector can be between the defibrillator electrode 32 and the housing electrode formed by or on the IMD 12, as discussed further below. In one instance, the therapeutic electrode vector can be considered as a line extending from a point on the defibrillator electrode 32 (e.g., the center of one of the defibrillator electrodes 32) to a point on the housing electrode of the IMD 12. Thus, it may be advantageous to increase the amount of area in which the defibrillator electrode 32 (and the distal portion of the lead 22) extends across the heart 18. Therefore, lead 22 can be configured to define, as Figure 1A The distal portion of the curve depicted herein. In some instances, in addition to the techniques used to control the delivery of the cardiac therapies described herein, the distal portion of the curve of lead 22 may also help improve the efficacy and / or efficiency of IMD 12 in pacing, sensing, and / or defibrillation of the heart 18.

[0040] Defibrillation electrodes 32A and 32B may be electrically connected to one or more conductors, which may be disposed within the body wall of lead 22 and / or within one or more insulating lumens (not shown) defined by lead 22. In some instances, each of defibrillation electrodes 32A and 32B is connected to a common conductor, such that IMD 12 can simultaneously apply voltage to all defibrillation electrodes 32A and 32B to deliver a defibrillation shock to the patient's heart (e.g., heart 18). In some instances, defibrillation electrodes 32A and 32B may be attached to separate conductors, such that IMD 12 can apply voltage to each defibrillation electrode 32 independently of the other defibrillation electrodes 32. In this case, IMD 12 or lead 22 may include one or more switches or other mechanisms to electrically connect the defibrillation electrode segments to the same or different voltage sources.

[0041] The housing 20 can be charged to or used with a polarity different from that of one or more defibrillator electrodes 32 and / or pacing / sensing electrodes 36, allowing electrical energy to be transferred between the housing 20 and the defibrillator electrodes 32 and / or pacing / sensing electrodes 36 to the heart 18. When voltage is applied to each defibrillator electrode 32, each defibrillator electrode can have the same polarity as each other defibrillator electrode 32, allowing a defibrillation shock to be delivered from each defibrillator electrode 32 to the housing 20. In instances where the defibrillator electrodes 32 are electrically connected to a common conductor within the lead body 12, this is the only configuration of the defibrillator electrodes 32. However, in other instances, the defibrillator electrodes 32 can be coupled to separate conductors within the lead body 22, and thus each can have a different polarity, allowing electrical energy to flow between the defibrillator electrodes 32, or between one or more of the defibrillator electrodes 32 and electrodes on the housing 20.

[0042] Pacing / sensing electrodes 36A and 36B (collectively referred to as “pacing / sensing electrodes 36”) may be located on the distal portion of lead 22. Electrode 36 may be referred to herein as a pacing / sensing electrode because it is generally configured for the delivery of pacing pulses and / or the sensing of cardiac electrical signals. In some cases, electrode 36 may provide pacing functionality only, sensing functionality only, or both pacing and sensing functionality. Pacing / sensing electrodes 36A and pacing / sensing electrodes 36B may be separated from defibrillation electrode 32A. In instances where lead 22 contains more or fewer electrodes 32, 36, such electrodes may be located at other locations on lead 22. In some instances, IMD 12 may contain one or more electrodes 32, 36 on another lead (not shown). Other lead configurations, such as various electrode arrangements, may be used. For example, one or more pacing / sensing electrodes 36 may be placed between two defibrillation electrodes 32, as described above. In one example, multiple pacing / sensing electrodes 36 may be placed between two defibrillation electrodes 32. In another example, the two defibrillation electrodes 32 may be adjacent (e.g., such that the two defibrillation electrodes 32 are not separated by any pacing / sensing electrodes 36 between them). Other arrangements may be used alternatively or additionally.

[0043] Lead 22 can be defined in different sizes and shapes, such as to suit different purposes (e.g., to suit different patients or to suit different therapies). As discussed above, in some instances, the distal portion of lead 22 may have a curved portion including one or more curved segments. Figure 1A As shown in the examples, the distal portion of lead 22 is curved, comprising two “C”-shaped curves that together resemble the Greek letter epsilon “ε”. Each defibrillator electrode 32 is carried by one of the two corresponding C-shaped bends of the distal portion of the lead body. The two C-shaped curves extend or bend away from the central axis of the lead body in the same direction. In some examples, the pacing / sensing electrode 36 may be substantially aligned with the central axis of the distal portion of lead 22. In such examples, the midpoint of defibrillator electrode 32 is laterally offset from pacing / sensing electrode 36. In some examples, the central axis of the distal portion of lead 22 represents a line passing through each of the pacing / sensing electrodes 36. Other examples of cardiovascular external leads comprising one or more defibrillator electrodes 32 and one or more pacing / sensing electrodes 36 carried by the curved (e.g., curved, meandering, wavy, or zigzag) distal portion of lead 22 can also be implemented using the techniques described herein. In some instances, the distal portion of lead 22 may be straight (e.g., straight or nearly straight).

[0044] In some instances, the electrode arrangement on lead 22 may correspond to the geometry of lead 22. For example, pacing / sensing electrode 36 may be positioned on a relative peak of a curved lead shape, while defibrillation electrode 32 may be positioned on a relative valley of a curved lead shape. In some cases, a relative valley may represent a curved portion of lead 22. Furthermore, an uncoated portion 34 may be located at the “bottom” of the corresponding curved portion or valley. In other instances, the distal portion of lead 22 may include branches, bias portions extending away from the central axis, or other shapes that can provide appropriate monitoring information or therapy (e.g., where one or more of electrodes 32, 36 are positioned on branches, axes, or bias portions). Deploying lead 22 such that electrodes 32, 36 are thus positioned at the peaks and valleys of these depicted curved shapes on the distal portion of lead 22 can enhance the effectiveness of system 10. For example, in addition to the techniques described herein for controlling the delivery of cardiac therapy, electrodes 32, 36 may also obtain a better sensing or therapy vector when lead 22 is deployed in a curved shape.

[0045] Compared to orienting the pacing / sensing electrode 36 further away from the heart 18, adjusting the orientation of the curved lead so that the pacing / sensing electrode 36 is closer to the heart 18 can provide better electrosensitivity of cardiac signals and / or a lower pacing capture threshold. The curve or other shape of the distal portion of the lead 22 can increase fixation to the patient 8 because the shape provides resistance to adjacent tissues when axial forces are applied. Another advantage of the shaped distal portion is that the pacing / sensing electrode 36 can achieve a larger surface area over a shorter length of the heart 18 compared to a lead with a straighter distal portion.

[0046] In some instances, the diameter of the elongated lead body of lead 22 can range from 3 French (Fr) to 12 Fr, but lead bodies with diameters less than 3 Fr and greater than 12 Fr can also be used. In another instance, the distal portion and / or other portions of the lead body can have a flat, strip, or paddle-shaped shape. In such instances, the width of the flat portion of the flat, strip, or paddle-shaped shape can be between 1 mm and 3.5 mm. Other lead body designs can be used without departing from the scope of this disclosure. The lead body of lead 22 can be formed of a non-conductive material comprising silicone, polyurethane, fluoropolymers, mixtures thereof, and other suitable materials, and shaped to form one or more cavities in which one or more conductors extend. However, the technique is not limited to such constructions.

[0047] In some instances, the defibrillator electrode 32 may have a length ranging from 2 centimeters (cm) to 16 centimeters. In some instances, in addition to elongated coil electrodes, the defibrillator electrode 32 may be a flat strip electrode, a paddle electrode, a braided or interwoven electrode, a mesh electrode, a segmented electrode, a directional electrode, a patch electrode, or other types of electrodes.

[0048] The pacing / sensing electrode 36 may include a ring electrode, a short coil electrode, a hemispherical electrode, a segmented electrode, a directional electrode, etc. In some examples, the pacing / sensing electrode 36 may have an outer diameter substantially the same as the lead body. In one example, the pacing / sensing electrode 36 may have a diameter ranging from 1 square millimeter (mm²). 2 ) to 55mm 2 The surface area within the range. In some instances, the pacing / sensing electrodes 36 may have relatively identical or different surface areas. Depending on the configuration of the lead 22, the pacing / sensing electrodes 36 may be spaced apart by the length of the defibrillator electrode 32 plus a certain insulation length on each side of the defibrillator electrode 32 (e.g., in the range of about 2 cm to 16 cm). In other instances, such as when a pair of pacing / sensing electrodes 36 are not separated by the defibrillator electrode 32, the electrode spacing may be smaller, for example, up to 2 cm. The example dimensions provided above are exemplary in nature and should not be considered as limitations on the examples described herein.

[0049] In some instances, the IMD 12 may include one or more housing electrodes (not shown) positioned on the housing 20 of the IMD 12. Such housing electrodes may be integrally formed with the outer surface of the hermetically sealed housing 20 of the IMD 12, or may be otherwise coupled to the housing 20. In some instances, the housing electrodes may be defined by an uninsulated portion of the externally facing part of the housing 20 of the IMD 12. In some instances, the housing 20 may define one or more additional housing electrodes, which may be defined by a corresponding division between insulating and non-insulated portions of the housing 20. In still other instances, substantially all of the housing 20 may be uninsulated, such that substantially all of the housing 20 defines housing electrodes.

[0050] Typically, system 10 can sense electrical signals via one or more vectors, said one or more vectors comprising a combination of the uncoated portion 34 of defibrillation electrode 32, pacing / sensing electrode 36, and / or the housing electrode of IMD 12. The sensed inherent electrical signals may include electrical signals generated by the myocardium and indicate depolarization and repolarization of the heart 18 at different times during the cardiac cycle. IMD 12 can be configured to analyze the electrical signals sensed by the one or more vectors to detect arrhythmias such as ventricular tachycardia (VT), ventricular fibrillation (VF), atrial tachycardia (AT), atrial fibrillation (AF), or any combination thereof. In response to the detection of an arrhythmia, in some cases, IMD 12 may initiate charging of a group of storage elements, such as one or more capacitors. While the capacitors are charged, IMD 12 may deliver substernal electrical therapy, such as antitachycardia pacing (ATP), cardioversion or defibrillation shock, bradycardia pacing, cardiac arrest pacing, and / or post-shock pacing. In some instances, in addition to ATP, cardioversion or defibrillation shock and / or post-shock pacing, IMD 12 can also generate and deliver bradycardia pacing.

[0051] In some instances, system 10 may include an external device 38. External device 38 may be a computing device configured for use in a home, outpatient, clinic, or hospital environment to communicate with IMD 12 via wireless telemetry. Examples of communication technologies used by IMD 12 and external device 38 include radio frequency (RF) telemetry, which may include communication via… An RF link established by a wireless local area network or a medical implantable communication service (MICS). Communication may include one-way communication, in which one device is configured to send communication messages and another device is configured to receive those messages. Alternatively or additionally, the communication may include bidirectional communication, in which each device is configured to send and receive communication messages.

[0052] External device 38 may include a communication circuitry configured to communicate with one or more devices (e.g., IMD 12) according to the technology and system 10 described above. For example, when external device 38 is configured as a programmer for IMD 12, it can be used to program commands or operating parameters of IMD 12 to control its functions. External device 38 can communicate with IMD 12 to retrieve data such as operational data and physiological data accumulated in the IMD's memory. Thus, external device 38 can function as a programmer for IMD 12, an external monitor for IMD 12, or a consumer device such as a smartphone. External device 38 can be connected to a remote patient monitoring system, such as those available from Medtronic plc in Dublin, Ireland. Network. In other instances, clinicians can use external device 38 to program or update therapy parameters for defined cardiac therapies, and / or program and update modifications to cardiac therapy parameters, sensing parameters, and / or electrode vectors associated with various cardiac positional states, or perform other activities with respect to IMD 12. Clinicians may be physicians, technicians, surgeons, electrophysiologists, or other healthcare professionals. In some instances, the user may be a patient 8.

[0053] Although described herein in the context of Example IMD 12, techniques for controlling the delivery of the cardiac therapies described herein can be implemented using other types of IMDs configured to deliver cardiac therapies. In some instances, the techniques described herein can be implemented using external defibrillators or other devices or systems configured to deliver cardiac therapies. Figure 1A-1C In the example shown, lead 22 may be implanted under the sternum, but in some examples, lead 22 may be implanted in other extravascular locations, including subcutaneous or submuscular locations under the sternum and / or anterior thoracic cavity.

[0054] Figure 2 This is a functional block diagram illustrating an example configuration of IMD 12 based on one or more technologies described herein. For example... Figure 2 As shown, the IMD 12 includes a processing circuit 50, a sensing circuit 52, a signal generation circuit 54, a sensor 56, a communication circuit 58, and a storage device 60. The storage device 60 can store treatment and sensing parameters 62 and collected data 64. In addition, the IMD 12 is electrically coupled to one or more electrodes 20, 32A, 32B, 36A, and 36B.

[0055] Processing circuitry 50 may comprise fixed-function circuitry systems and / or programmable processing circuitry systems. Processing circuitry 50 may comprise any one or more of the following: microprocessors, controllers, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or equivalent discrete or analog logic circuitry systems. In some instances, processing circuitry 50 may comprise multiple components (e.g., any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, or one or more FPGAs) and other discrete or integrated logic circuitry systems. The functionality attributed herein to processing circuitry 50 may be embodied in software, firmware, hardware, or any combination thereof.

[0056] Sensing circuit 52 monitors electrocardiogram (ECG) signals from any combination of electrodes 20, 32A, 32B, 36A, and 36B, which form electrode vector groups. In some instances, sensing circuit 52 may include one or more amplifiers, filters, and analog-to-digital converters. For example, sensing circuit 52 may include one or more detection channels, each of which may include an amplifier. Detection channels can be used to sense cardiac signals, such as cardiac EGM. Channels can detect cardiac EGM signals from specific combinations (e.g., vectors) of electrodes 20, 32A, 32B, 36A, and 36B. Some detection channels can detect events such as R waves, P waves, and T waves and provide indications of the occurrence of such events to processing circuit 50. One or more other detection channels can provide signals to an analog-to-digital converter (ADC) for conversion into digital signals for processing, analysis, storage, or output by processing circuit 50.

[0057] Each detection channel of sensing circuit 52 may include a filter configured to pass through a custom range of frequency values. For example, sensing circuit 52 may include one or more narrowband channels, each of which may include a narrowband filtered sensing amplifier. Alternatively, sensing circuit 52 may include one or more wideband channels, each of which includes an amplifier having a passband relatively wide compared to the narrowband channels. The signals sensed by the narrowband and wideband channels of sensing circuit 52 can be converted into multi-bit digital signals by an ADC provided by, for example, sensing circuit 52 or processing circuit 50. In some instances, processing circuit 50 analyzes the digitized version of the signal from sensing circuit 52. In other instances, processing circuit 50 stores the digitized version of the signal in storage device 60 (e.g., as collected data 64) and outputs the digitized version of the signal via communication circuit 58 or any combination thereof. Threshold, filter parameter values, blanking interval, and other parameter values ​​for controlling the sensing and processing of cardiac signals by sensing circuit 52 and processing circuit 50 may be stored in storage device 60 as treatment and sensing parameters 62.

[0058] Typically, processing circuitry 50 controls signal generation circuitry 54 to deliver a therapy to the heart 18 of patient 8 based on selected values ​​of therapy and sensing parameters 62 that can be stored in storage device 60. As an example, processing circuitry 50 may control signal generation circuitry 54 to deliver electrical pulses having amplitude, pulse width, frequency, and / or electrode polarity (which define the therapy vector) specified by therapy and sensing parameters 62. Therapy and sensing parameters 62 stored in storage device 60 may include thresholds or other conditions that can be compared to parameters of the EGM, and based on these parameters, processing circuitry 50 controls signal generation circuitry 54 to deliver therapies such as heart rate, intervals, and / or EGM morphological parameters.

[0059] The signal generation circuit 54 is configured to generate and deliver electrotherapy to the patient 8. For example... Figure 2 As shown, the signal generation circuit 54 is electrically coupled to electrodes 20, 32A, 32B, 36A, and 36B, for example, via conductors within the respective leads 22, and, if the electrodes are positioned on the housing 20 of the IMD 12, via conductors within the housing 20. For example, the signal generation circuit 54 may deliver pacing, defibrillation, or cardioversion pulses to the heart 18 via at least two of electrodes 20, 32A, 32B, 36A, and 36B. In some instances, the signal generation circuit system 54 delivers therapy in a signal form other than pulses (such as sine waves, square waves, or other substantially continuous time signals). In some instances, the signal generation circuit 54 may include one or more capacitors, charge pumps, current sources, or other signal generation circuitry.

[0060] Sensing circuit 52 and signal generation circuit 54 can be selectively coupled to electrodes 20, 32A, 32B, 36A, and 36B, for example via a switching circuit controlled by processing circuit 50. Figure 2 (Not shown in the diagram). The switching circuit may include one or more transistors or other circuitry for selectively coupling electrodes 20, 32A, 32B, 36A, and 36B to other circuitry of the IMD 12. The sensing circuitry 52 may monitor signals from electrodes 20, 32A, 32B, 36A, and 36B to monitor cardiac electrical activity (e.g., detect depolarization for heart rate determination and / or generate an electrocardiogram for morphological or other analysis).

[0061] Sensor 56 may include one or more accelerometers. Sensor 56 may additionally or alternatively include other sensors, such as gyroscopes, magnetometers, barometers, acoustic sensors, pressure sensors, flow sensors, and oxygen (O2) saturation sensors. As examples, information obtained from sensor 56 can be used to determine activity level, posture, blood pressure, blood flow, blood oxygen level, or respiratory rate. In some instances, processing circuitry 50 may use this information to aid in the classification of abnormal heart rhythms. In some instances, at least some of sensor 56 may be located outside the housing 20 of IMD 12. Sensor 56 may be located on leads (such as lead 22) coupled to IMD 12, or may be implemented in a remote sensor that wirelessly communicates with IMD 12 via communication circuitry 58. In any case, sensor 56 is electrically or wirelessly coupled to circuitry contained within the housing 20 of IMD 12.

[0062] The communication circuit 58 may include any suitable hardware, firmware, software, or any combination thereof for communicating with another device, such as external device 38. Under the control of the processing circuit 50, the communication circuit 58 can receive downlink telemetry from external device 38 or another device, and send uplink telemetry to it. In some instances, the communication circuit 58 has an internal or external antenna ( Figure 2 Information can be exchanged with the help of an external device (e.g., external device 38) or a Medtronic device developed by Medtronic Corporation of Dublin, Ireland. Computer networks such as Network communicate with networked computing devices. Communication circuit 58 may include... Radio, electronic oscillators, frequency modulation circuit systems, frequency demodulation circuit systems, amplifier circuit systems, and power switches such as metal-oxide-semiconductor field-effect transistors (MOSFETs), bipolar junction transistors (BJTs), insulated-gate bipolar transistors (IGBTs), junction field-effect transistors (JFETs), or any combination of other elements for controlling the voltage used thereunder.

[0063] Storage device 60 can be configured to store information within IMD 12 during operation. Storage device 60 may comprise a computer-readable storage medium or a computer-readable storage device. In some instances, storage device 60 comprises one or more of short-term or long-term memory. Storage device 60 may comprise, for example, random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), magnetic disk, optical disk, flash memory, or various forms of electrically programmable memory (EPROM) or electrically erasable programmable memory (EEPROM). In some instances, storage device 60 is used to store data indicating instructions to be executed by processing circuitry 50.

[0064] In some instances, the IMD 12 can be configured to sense cardiac signals using sensing circuitry 52 based on a selected set of one or more vectors. Processing circuitry 50 can control sensing circuitry 52 to obtain data on the potential difference between nodes corresponding to each vector in the vector set. Each vector node can correspond to a pair of electrodes 20, 32A, 32B, 36A, and 36B, or more than two electrodes 20, 32A, 32B, 36A, and 36B if two of the electrodes are connected as a common node. Each of electrodes 20, 32A, 32B, 36A, and 36B, including electrodes 32 and 36, can be coupled to sensing circuitry 52 via a corresponding electrical conductor. In this way, the IMD 12 can be able to obtain a signal (e.g., a signal indicating potential) using each of electrodes 20, 32A, 32B, 36A, and 36B. Vectors can be defined by a set of parameters including the combination of two or more electrodes, the spatial arrangement of the two or more electrodes, and the polarity of each of the two or more electrodes.

[0065] For example, processing circuit 50 may be configured to control sensing circuit 52 to obtain a first electrogram via a first vector including a first pacing / sensing electrode 36A and a second pacing / sensing electrode 36B. In some instances, the first electrogram is proportional to the potential difference between the first pacing / sensing electrode 36A and the second pacing / sensing electrode 36B. Furthermore, processing circuit 50 may be configured to control sensing circuit 52 to obtain a second electrogram via a second vector including an uncoated portion 34 of the first pacing / sensing electrode 36A and the first defibrillator electrode 32A. In some instances, the second electrogram is proportional to the potential difference between the first pacing / sensing electrode 36A and the uncoated portion 34. The second vector may form a first angle with the first vector. In other words, a line passing through the first pacing / sensing electrode 36A and the second pacing / sensing electrode 36B may form a first angle with a line passing through the first pacing / sensing electrode 36A and the uncoated portion 34. In some instances, the first angle is in the range of thirty to sixty degrees. However, the first angle is not necessarily limited to such a range. In some cases, the first angle can be less than thirty degrees or greater than sixty degrees.

[0066] Since cardiac depolarization is inherently directional and follows a three-dimensional path through the heart 18 of patient 8, it may be beneficial for the first vector to form an angle with the second vector, so that IMD 12 may be able to obtain different angular perspectives of directional cardiac depolarization, for example, allowing selection of one of the vectors that provides preferred signal features.

[0067] Additionally, the processing circuit 50 can control the sensing circuit 52 to obtain a third electrogram via a third vector comprising the uncoated portion 34 of the second pacing / sensing electrode 36B and the first defibrillator electrode 32A. In some instances, the third electrogram is proportional to the potential difference between the second pacing / sensing electrode 36B and the uncoated portion 34. The third vector may form a second angle with the first vector. In other words, the line passing through the first pacing / sensing electrode 36A and the second pacing / sensing electrode 36B may form a second angle with the line passing through the second pacing / sensing electrode 36B and the uncoated portion 34. In some instances, the second angle is in the range of thirty to sixty degrees. However, the second angle is not necessarily limited to such a range. In some cases, the second angle may be less than thirty degrees or greater than sixty degrees. It may be advantageous for the third vector to form an angle with the first vector so that, in addition to the perspectives provided by the first and second vectors, the IMD 12 can obtain another angular perspective for directional cardiac depolarization. Furthermore, the second and third vectors can form an angle (e.g., in the range of 30 to 120 degrees) such that the first, second, and third vectors form a triangle between the first pacing / sensing electrode 36A, the second pacing / sensing electrode 36B, and the uncoated portion 34.

[0068] In some cases, the first pacing / sensing electrode 36A, the second pacing / sensing electrode 36B, and the uncoated portion 34 may be located close to the ventricle of the heart 18. In some cases, the processing circuitry 50 may store one or more of the first, second, and third electrograms in the storage device 60 as part of the collected data 64, wherein the first, second, and third electrograms are different.

[0069] In addition to being configured to selectively determine data corresponding to a first, second, and / or third vector located near the ventricle of heart 18, processing circuitry 50 can also be configured to guide sensing circuitry 52 to collect data via electrodes proximate to the atrium of heart 18. For example, processing circuitry 50 can control sensing circuitry 52 to obtain a fourth electrogram via a fourth vector, which includes a second pacing / sensing electrode 36B and a third pacing / sensing electrode (not shown in Figures 1 and 2) distal to defibrillation electrode 32B. In some instances, the fourth electrogram is proportional to the potential difference between the second pacing / sensing electrode 36B and the third pacing / sensing electrode. Additionally, processing circuitry 50 can control sensing circuitry 52 to obtain a fifth electrogram via a fifth vector including the second pacing / sensing electrode 36B and a second uncoated portion (not shown) located on the second defibrillation electrode 32B. In some instances, the fifth electrogram is proportional to the potential difference between the second pacing / sensing electrode 36B and the second uncoated portion. The fifth vector may form a third angle with the fourth vector. In other words, the lines passing through the second pacing / sensing electrode 36B and the third pacing / sensing electrode can form a third angle with the lines passing through the second pacing / sensing electrode 36B and the second uncoated portion. In some instances, the third angle is in the range of thirty to sixty degrees. However, the third angle is not necessarily limited to such a range. In some cases, the third angle can be less than thirty degrees or greater than sixty degrees. Since cardiac depolarization is inherently directional and follows a three-dimensional path through the heart 18 of the patient 8, it may be beneficial for the fifth vector to form an angle with the fourth vector so that the IMD 12 obtains different angular perspectives of directional cardiac depolarization based on the fourth and fifth vectors.

[0070] Furthermore, the processing circuit 50 can control the sensing circuit 52 to obtain a sixth electrogram via a sixth vector comprising a second uncoated portion of the third pacing / sensing electrode and the second defibrillator electrode 32B. In some instances, the sixth electrogram is proportional to the potential difference between the third pacing / sensing electrode and the second uncoated portion. The sixth vector can form a fourth angle with a fourth vector. In other words, a line passing through the second pacing / sensing electrode 36B and the third pacing / sensing electrode can form a fourth angle with a line passing through the third pacing / sensing electrode and the second uncoated portion. In some instances, the fourth angle is in the range of thirty to sixty degrees. However, the fourth angle is not necessarily limited to such a range. In some cases, the fourth angle can be less than thirty degrees or greater than sixty degrees. It may be advantageous for the sixth vector to form an angle with the fourth vector so that, in addition to the perspectives provided by the fourth and fifth vectors, the IMD 12 can obtain another angular perspective for directional cardiac depolarization. Furthermore, the fifth and sixth vectors can form an angle (e.g., in the range of 30 to 120 degrees) such that the fourth, fifth, and sixth vectors form a triangle between the second pacing / sensing electrode 36B, the third pacing / sensing electrode, and the second uncoated portion.

[0071] In some cases, the second pacing / sensing electrode 36B, the third pacing / sensing electrode, and the second uncoated portion may be located close to the atrium of the heart 18. In some cases, the processing circuitry 50 may be configured to store the fourth, fifth, and sixth electrograms as part of the collected data 64 in the storage device 60, wherein the fourth, fifth, and sixth electrograms are distinct.

[0072] Although the description of sensing cardiac depolarization herein includes a vector group comprising a first vector, a second vector, a third vector, a fourth vector, a fifth vector, and a sixth vector, the IMD 12 may also deliver electrical stimulation (e.g., pacing pulses) based on the vector group. For example, processing circuitry 50 may control signal generation circuitry 54 to deliver electrical stimulation based on any one or more of the first, second, and third vectors to deliver electrical stimulation to the ventricles of heart 18. Additionally, processing circuitry 50 may control signal generation circuitry 54 to deliver electrical stimulation based on any one or more of the fourth, fifth, and sixth vectors to deliver electrical stimulation to the atria of heart 18. Since each of the vector groups provides a different perspective of heart 18, it may be advantageous for the IMD 12 to selectively deliver electrical stimulation based on one or more selected vectors from the vector group.

[0073] Power source 66 is configured to deliver operating power to the components of IMD 12. Power source 66 may include a battery and power generation circuitry for generating operating power. In some instances, the battery is rechargeable to allow for extended operation. In some instances, recharging is achieved through proximal inductive interaction between an external charger and an inductive charging coil within IMD 12. Power source 66 may include any one or more of a variety of battery types, such as nickel-cadmium batteries and lithium-ion batteries.

[0074] Although about Figure 2 Six vectors are described, and processing circuitry 50 can be configured to determine data corresponding to other vectors. These other vectors can represent differences in measurement parameters between any two or more of electrodes 20, 32A, 32B, 36A, and 36B. For example, although the six vectors are described herein as including two electrodes, one or more techniques of this disclosure can be implemented such that a vector can include three or more electrodes, wherein at least two of the three or more electrodes are connected as a common node. Thus, a vector can include two nodes, each node including one or more electrodes. Furthermore, regarding... Figure 2 Each of the six vectors described can correspond to a vector of opposite polarity. For example, IMD 12 can change the polarity of any of the six vectors to obtain data corresponding to the vector of the opposite polarity.

[0075] Clinicians or other users can retrieve data from the IMD 12 using external device 38 or by using another local or networked computing device (e.g., a remote computer located with the clinician) configured to communicate with the processing circuitry 50 via communication circuitry 58. For example, a clinician can retrieve collected data 64 for analysis using external device 38. In some instances, clinicians can also use external device 38 or another local or networked computing device to program parameters of the IMD 12 (e.g., therapy and sensing parameters 62).

[0076] Although the processing circuitry 50 of the IMD 12 is described above as being configured to control the sensing circuitry 52 to sense electrocardiogram signals and to control the signal generation circuitry 54 to transmit cardiac pacing based on one or more vectors selected from a vector group, any steps described herein as performed by the processing circuitry 50 of the IMD 12 can be performed by the processing circuitry of one or more other devices. For example, the processing circuitry system of an external device 38, a remote computer, or any other suitable implantable or external device or server can be configured to perform one or more steps of the techniques described herein, as via the communication circuitry 58 of the IMD 12.

[0077] Figure 3This is a block diagram illustrating an example configuration of components of an external device 38 according to one or more technologies described herein. Figure 3 In this example, external device 38 includes processing circuitry 80, communication circuitry 82, storage device 84, user interface 92, and power supply 94. Storage device 84 is configured to store operating parameters 86 and retrieved data 88.

[0078] In one example, processing circuitry 80 may include one or more processors configured to implement functions and / or processing instructions for execution within external device 38. For example, processing circuitry 80 may be able to process instructions stored in storage device 84. Processing circuitry 80 may include, for example, a microprocessor, DSP, ASIC, FPGA, or equivalent discrete or integrated logic circuit system, or a combination of any of the foregoing devices or circuit systems. Therefore, processing circuitry 80 may include any suitable structure for performing the functions attributed herein to processing circuitry 80, whether in hardware, software, firmware, or any combination thereof.

[0079] The communication circuit 82 may include any suitable hardware, firmware, software, or any combination thereof for communicating with another device such as the IMD 12. Under the control of the processing circuit 80, the communication circuit 82 can receive downlink telemetry from the IMD 12 or another device, and send uplink telemetry to it. In some instances, the communication circuit 82 includes a first set of communication circuit systems configured to transmit and receive signals according to a communication protocol developed by the manufacturer of the IMD 12 or a third-party developer. In some such instances, the communication circuit 82 further includes a second set of communication circuit systems defining... Radio, which is configured to... The communication circuit 82 transmits and receives signals according to a communication protocol. However, the communication circuit 82 does not necessarily include separate sets of circuit systems corresponding to different communication protocols. In some instances, the communication circuit 82 includes a single set of circuit systems configured to transmit and receive signals according to multiple communication protocols.

[0080] In some instances, the communication circuit 82 includes Radio, electronic oscillator, frequency modulation circuit system, frequency demodulation circuit system, amplifier circuit system, and any combination of power switches such as MOSFET, BJT, IGBT, JFET, or other components for controlling the voltage used therein.

[0081] Storage device 84 can be configured to store information within external device 38 during operation. Storage device 84 may comprise a computer-readable storage medium or a computer-readable storage device. In some instances, storage device 84 comprises one or more of short-term memory or long-term memory. Storage device 84 may comprise, for example, RAM, DRAM, SRAM, magnetic disk, optical disk, flash memory, or various forms of EPROM or EEPROM. In some instances, storage device 84 is used to store data indicating instructions to be executed by processing circuitry 80. Storage device 84 can be used by software or applications running on external device 38 to temporarily store information during program execution.

[0082] The data exchanged between the external device 38 and the IMD 12 may include any operating parameters in the operating parameters 86 stored in the storage device 84. The external device 38 may transmit data containing computer-readable instructions that, when implemented by the IMD 12, can control the IMD 12 to change one or more operating parameters according to the operating parameters 86 and / or export collected data. For example, the processing circuitry 80 may transmit instructions to the IMD 12 requesting it to export collected data (e.g., a portion of collected data 64) to the external device 38. Furthermore, the external device 38 may receive the collected data from the IMD 12 and store it in the storage device 84 (e.g., as retrieved data 88). Alternatively or additionally, the processing circuitry 80 may export instructions to the IMD 12 to request it to update the electrode vectors used for treatment or sensing according to the operating parameters 86. For example, the processing circuit 80 can output a command to the IMD 12, requesting the IMD 12 to update which vectors (e.g., the first vector, the second vector, the third vector, the fourth vector, the fifth vector, the sixth vector, or another vector) are used to monitor the electrical signals of the heart 18.

[0083] Users such as clinicians or patients 8 can interact with external devices 38 through user interface 92. User interface 92 includes a display (not shown), such as an LCD or LED display or other type of screen, which processing circuitry 80 can use to present information related to IMD 12 (e.g., an EGM signal obtained using one of the vector groups). Additionally, user interface 92 may include an input mechanism to receive input from the user. The input mechanism may include, for example, buttons, a keypad (e.g., an alphanumeric keypad), a peripheral pointing device, or a touchscreen, or another input mechanism that allows the user to navigate the user interface presented by processing circuitry 80 of external device 38 and provides input. In other instances, user interface 92 also includes an audio circuitry system for providing auditory notifications, instructions, or other sounds to patient 8, receiving voice commands from patient 8, or both. Storage device 84 may contain instructions for operating user interface 92 and for managing power supply 94.

[0084] Power source 94 is configured to deliver operating power to components of external device 38. Power source 94 may include a battery and power generation circuitry for generating operating power. In some instances, the battery is rechargeable to allow for extended operation. Recharging can be accomplished by electrically coupling power source 94 to a bracket or plug connected to an AC outlet. Alternatively, recharging can be achieved through near-end inductive interaction between an external charger and an inductive charging coil within external device 38. In other instances, conventional batteries (e.g., nickel-cadmium or lithium-ion batteries) can be used. Furthermore, external device 38 can be directly coupled to an AC outlet for operation.

[0085] Figure 4A This is a front view of the distal portion of a medical lead 22 according to one or more techniques described herein. In the illustrated example, lead 22 includes a first defibrillator electrode 32A, a second defibrillator electrode 32B, a first pacing / sensing electrode 36A, and a second pacing / sensing electrode 36B. The first defibrillator electrode 32A includes a proximal coated portion 33A, a distal coated portion 33B, and an uncoated portion 34 located between the proximal coated portion 33A and the distal coated portion 33B. In some examples, the proximal coated portion 33A is a first proximal coated portion, the distal coated portion 33B is a first distal coated portion, and the uncoated portion 34 is a first uncoated portion. Figure 4A In some examples not shown, the second defibrillator 32B includes a second proximal coated portion, a second distal coated portion, and a second uncoated portion located between the second proximal coated portion and the second distal coated portion.

[0086] In some instances, the defibrillator 32 is a coil electrode formed of a conductor. For example, the first defibrillator 32A and the second defibrillator 32B may represent coil electrodes disposed in line with the wall of the lead 22, surrounding the outside of the wall of the lead 22, or within the wall of the lead 22. Furthermore, in some instances, the defibrillator 32 may be a flat strip electrode segment, a paddle-shaped electrode segment, a braided or woven electrode segment, a mesh electrode segment, a directional electrode segment, a patch electrode segment, or other types of electrode segment configured to deliver a defibrillation shock to the heart 18. The defibrillator 32 may be made of any of a variety of conductive materials, including but not limited to metals, metal oxides, metal alloys, coated metals, and composite materials based on combinations of platinum, gold, iridium, titanium, tantalum, vanadium, aluminum, copper, zirconium, carbon, graphene, diamond, zirconium, diamond-like carbon coating (DLC), silicon, and / or boron. This also includes glasses and dielectric materials, such as borosilicate or chalcogenide glasses, zirconium oxide, alumina, and conductive polymers, semiconductors, and conductive ceramics in their pure form or with additives such as boron, carbon, gold, silver, and similar metal particles and / or fibers ranging from micrometer to nanometer size.

[0087] In some instances, an electrically insulating material covers the corresponding conductor of the defibrillation electrode 32A at the coating portion 33. In some cases, the electrically insulating material prevents the conduction of relatively low voltage signals (e.g., less than 100 volts (V)) between the coating portion 33 and the tissue of the patient 8. Alternatively, the electrically insulating material may allow the conduction of relatively high voltage signals (e.g., greater than or equal to 100 V) between the coating portion 33 and the tissue of the patient 8. For example, the coating portion 33 may be configured to prevent the transmission of pacing pulses, prevent the sensing of cardiac depolarization, and allow the transmission of defibrillation shocks, since the voltage of a defibrillation shock is significantly higher than the voltages of cardiac depolarization and pacing pulses. The electrically insulating material can be any of a variety of materials, such as a single or combination of the following: tantalum pentoxide, titanium oxide, zirconium oxide, vanadium oxide, niobium oxide, doped silicon, silicon dioxide, boron-doped diamond, doped glass, ceramic coatings, or polymer composites, or other materials having the property of substantially preventing the transmission or delivery of low voltages while substantially not preventing the transmission or delivery of high voltages.

[0088] In some instances, the defibrillator electrode 32A is not coated with an electrically insulating material at the uncoated portion 34. In other words, the uncoated portion 34 may represent a section of exposed conductive material on the defibrillator electrode 32A, such a section allowing the transmission of lower voltage signals. For example, the uncoated portion 34 may be configured to allow the conduction of relatively low voltage signals (e.g., less than 100V) and relatively high voltage signals (e.g., greater than or equal to 100V). For example, the uncoated portion 34 may be configured to transmit a defibrillation shock, transmit a pacing pulse, sense an electrical signal corresponding to cardiac depolarization, or any combination thereof. Thus, the entire length of the defibrillator electrode, such as defibrillator electrode 32A, may be configured to conduct a defibrillation shock transmitted by the signal generation circuitry within the housing 20, and a portion of defibrillator electrode 32A (e.g., the uncoated portion 34) may be configured to transmit a pacing pulse and sense cardiac depolarization. In this way, the uncoated portion 34 of defibrillator electrode 32A may perform at least some of the same functions as the pacing / sensing electrode 36.

[0089] In some instances, the electrical insulating material may extend around the entire circumference of the coated portion 33 of the defibrillator electrode 32. In other instances, the electrical insulating material may extend around a portion of the circumference of the coated portion 33. For example, the electrical insulating material may extend around the circumference of a portion of the coated portion 33 facing the heart 18. The electrical insulating material may be any of a variety of materials, such as a single or combination of the following: tantalum pentoxide, titanium oxide, zirconium oxide, vanadium oxide, niobium oxide, doped silicon, silicon dioxide, boron-doped diamond, doped glass, ceramic coating, or polymer composite material, or other materials having the property of substantially preventing the transmission or conduction of low voltages while substantially not preventing the transmission or conduction of high voltages. The thickness of the electrical insulating material may vary based on the type of material used to fabricate the defibrillator electrode 32A, the type of electrical insulating material, the size of the corresponding coated portion 33, and the intended depth and location of the distal portion of the lead 22, such as a substernal or subcutaneous location. In instances where tantalum pentoxide is the electrical insulating material, the thickness of the electrical insulating material may range from 0.2 micrometers (μm) to less than or equal to 2.0 μm. However, other thicknesses may be used without departing from the scope of this disclosure. In one example, the coating portion 33 is coated with tantalum pentoxide with a thickness ranging from 0.6 μm to 0.9 μm. In such an example, the tantalum pentoxide coating significantly impedes the flow of current up to 100 V, thereby preventing the sensing of cardiac depolarization events and blocking the transmission of pacing pulses. Furthermore, in such an example, electrical signals with voltages higher than 100 V (e.g., defibrillation shock) overcome the electrical insulation properties of the tantalum pentoxide coating and can be conducted through the coating portion 33 of the defibrillation electrode 32.

[0090] The length of each defibrillator electrode 32 can be between 2 cm and 16 cm. However, without departing from the scope of this disclosure, a length greater than 16 cm and less than 2 cm can be used. In some instances, defibrillator electrodes 32A and 32B have the same length. In other instances, defibrillator electrodes 32A and 32B have different lengths. In some instances, the first defibrillator electrode 32A and the second defibrillator electrode 32B can be spaced apart on the lead 22 by a distance ranging from 0.1 cm to 3 cm. Figure 4A In the illustrated example, the first defibrillator electrode 32A and the second defibrillator electrode 32B are spaced apart sufficiently such that the second pacing / sensing electrode 36B is positioned between the first defibrillator electrode 32A and the second defibrillator electrode 32B. In some examples, the second pacing / sensing electrode 36B may be located at or near the midpoint of the segment (i.e., lead segment 98) along lead 22 that separates the first defibrillator electrode 32A and the second defibrillator electrode 32B. For example, the center of the second pacing / sensing electrode 36B may be located between 35% and 65% of the length of lead segment 98 from its proximal end. In other words, in an example where the length of lead segment 98 is 2 cm, the center of the second pacing / sensing electrode 36B may be located between 0.7 cm and 1.3 cm from the proximal end of the first lead segment 98.

[0091] The dimensions of the coated portion 33 and the uncoated portion 34 may differ. In some instances, the uncoated portion (e.g., uncoated portion 34) may be less than or equal to 25% of the length of the corresponding defibrillator electrode 32A. Furthermore, in some instances, the uncoated portion 34 may be less than or equal to 10% of the length of the corresponding defibrillator electrode 32A. In some instances, the combined length and / or surface area of ​​all uncoated portions 34 of the defibrillator electrode 32 may be less than or equal to 25% or less than or equal to 10% of the combined length and / or surface area of ​​the defibrillator electrode 32. In some instances, each uncoated portion 34 may have a size less than or equal to 100 square millimeters (mm²). 2 The surface area of ​​the uncoated portion 34 may be less than or equal to 10 mm. 2 The surface area. Uncoated and coated portions may have dimensions different from those mentioned above.

[0092] The uncoated portion 34 may be located at or near the midpoint of the length of the first defibrillator electrode 32A. For example, the center of the uncoated portion 34 may be located between 35% and 65% of the length of the first defibrillator electrode 32A from its proximal end. In other words, in an example where the length of the first defibrillator electrode 32A is 5 cm, the center of the uncoated portion 34 may be located between 1.75 cm and 3.25 cm from its proximal end. In this way, based on the position of the uncoated portion 34 along the first defibrillator electrode 32A, the corresponding coated portions (e.g., proximal coated portion 33A and distal coated portion 33B) may have the same or different lengths. For example, if the uncoated portion 34 is closer to the proximal end of the first defibrillator 32A than the distal end of the first defibrillator 32A, then the length of the proximal coated portion 33A can be shorter than the length of the distal coated portion 33B. Conversely, if the uncoated portion 34 is closer to the distal end of the first defibrillator 32A than the proximal end of the first defibrillator 32A, then the length of the proximal coated portion 33A can be longer than the length of the distal coated portion 33B.

[0093] Figure 4B This is a conceptual diagram illustrating a vector obtainable from the distal portion of the medical lead 22, based on one or more techniques described herein. Figure 4B The example shown includes the uncoated portion 34A of the defibrillator electrode 32A, the first pacing / sensing electrode 36A, and the second pacing / sensing electrode 36B. Furthermore, Figure 4B The diagram illustrates the first vector 110A, the second vector 110B, the third vector 110C (collectively referred to as "vector 110") and the angles 112A-112C (collectively referred to as "angle 112").

[0094] In some instances, the IMD 12 can be configured to sense an electrocardiogram via electrodes on the distal portion of lead 22, for example, including cardiac depolarization, or other electrical signals according to vector 110. In some cases, each vector of 110 can represent the potential difference between corresponding potential signals obtained by a pair of electrodes (e.g., the uncoated portion 34 of defibrillation electrode 32, pacing / sensing electrode 36, and any combination of electrodes disposed on the housing 20 of IMD 12). In some instances, the vectors can be defined by a set of parameters including the combination of two or more electrodes, the spatial arrangement of the two or more electrodes, and the polarity of each of the two or more electrodes.

[0095] For example, processing circuitry 50 may be configured to control sensing circuitry 52 to obtain a first electrogram via a first vector 110A including a first pacing / sensing electrode 36A and a second pacing / sensing electrode 36B. In some instances, the first electrogram is proportional to the potential difference between the first pacing / sensing electrode 36A and the second pacing / sensing electrode 36B. Furthermore, processing circuitry 50 may control sensing circuitry 52 to obtain a second electrogram via a second vector 110B including an uncoated portion 34 of the first pacing / sensing electrode 36A and the first defibrillator electrode 32A. In some instances, the second electrogram is proportional to the potential difference between the first pacing / sensing electrode 36A and the uncoated portion 34. The second vector 110B may form an angle 112A with the first vector 110A. In some instances, angle 112A is in the range of 30 degrees to 60 degrees. In one instance, angle 112A is 45 degrees. Since cardiac depolarization is inherently directional and follows a three-dimensional path through the heart 18 of patient 8, it may be beneficial for the first vector 110A to form an angle with the second vector 110B, so that IMD 12 can obtain different angular perspectives of directional cardiac depolarization.

[0096] Additionally, the processing circuit 50 can control the sensing circuit 52 to obtain a third electrogram via a third vector 110C comprising the uncoated portion 34 of the second pacing / sensing electrode 36B and the first defibrillator electrode 32A. In some instances, the third electrogram is proportional to the potential difference between the second pacing / sensing electrode 36B and the uncoated portion 34. The third vector 110C may form an angle 112B with the first vector 110A. In some instances, the angle 112B is in the range of 30 degrees to 60 degrees. For example, the angle 112B may be 45 degrees. It may be advantageous for the third vector 110C to form an angle with the first vector 110A, so that the IMD 12 can obtain another angular perspective for directional cardiac depolarization in addition to the perspectives provided by the first vector 110A and the second vector 110B. Furthermore, the second vector 110B and the third vector 110C can form an angle 112C, such that the first vector 110A, the second vector 110B, and the third vector 110C form a triangle between the first pacing / sensing electrode 36A, the second pacing / sensing electrode 36B, and the uncoated portion 34. In some instances, the angle 112C is in the range of 60 degrees to 120 degrees. For example, the angle 112C can be 90 degrees. Since the first vector 110A, the second vector 110B, and the third vector 110C form a triangle, the sum of the angles 112A, 112B, and 112C can be 180 degrees.

[0097] In some cases, the first pacing / sensing electrode 36A, the second pacing / sensing electrode 36B, and the uncoated portion 34 may be located close to the ventricle of the heart 18. In some cases, the IMD 12 may store the first, second, and third electrograms in a storage device (e.g., storage device 60).

[0098] Although this document describes a vector group including vector 110 regarding sensing cardiac depolarization, the IMD 12 can also deliver electrical stimulation (e.g., pacing pulses) based on vector 110. For example, processing circuitry 50 can control signal generation circuitry 54 to deliver electrical stimulation based on any one or more of the first vector 110A, second vector 110B, and third vector 110C to deliver electrical stimulation to the ventricles of heart 18. Since each of the vector groups provides a different perspective about heart 18, it can be advantageous for the IMD 12 to deliver electrical stimulation based on different combinations of vector groups.

[0099] Because lead 22 is implanted in patient 8 and patient 8 moves around over time, lead 22 may move relative to heart 18 after implantation. In some cases, angle 112 may change over time due to this migration. For example, if the distal portion of lead 22 is compressed to move the pacing / sensing electrode 36 closer together, angles 112A and 112B may increase while angle 112C decreases. Furthermore, if the distal portion of lead 22 is stretched to move the pacing / sensing electrode 36 further, angles 112A and 112B may decrease while angle 112C increases. Any kind of relative movement between the uncoated portion 34 and the pacing / sensing electrode 36 may cause a change in angle 112. Although regarding... Figure 4B Three vectors 110 are described, but IMD 12 can be configured according to... Figure 4B Other vectors, not shown, collect data or deliver treatment (e.g., pacing pulses). Such other vectors may represent differences in measurement parameters between any two or more of the uncoated portion 34 of the defibrillator electrode 32, the pacing / sensing electrode 36, and the electrodes disposed on the canister 20 of the IMD 12.

[0100] Figure 5A This is a side view of the distal portion of a medical lead 22 according to one or more techniques described herein. Although the distal portion of the medical lead 22 forms a curved shape, it appears straight when viewed from the side. For example, the curved portion of the distal portion of the medical lead 22 extends into and out of... Figure 5A The plane. In other words, Figure 5A The diagram illustrates a view of lead 22, where, as shown... Figure 4AThe line extending from A to A' seen in the image extends into the page. Therefore, the defibrillator electrode 32 with coated portion 33 and uncoated portion 34, and the pacing / sensing electrode 36 can be... Figure 5A The middle is represented by the side view of the far end of the lead 22.

[0101] Figure 5B This is a side view of the distal portion of another example medical lead 120 according to one or more techniques described herein. Apart from the differences outlined below, the medical lead 120 may resemble medical lead 22. Figure 5B Examples may include a first defibrillator 122A and a second defibrillator 122B (collectively referred to as "defibrillator 122"), and a pacing / sensing electrode 126A and a pacing / sensing electrode 126B (collectively referred to as "pacing / sensing electrode 126"). Defibrillator 122A includes a coated portion 123 and an uncoated portion 124. In some cases, the second defibrillator 122B may be completely uncoated. Figure 5B Instances can be with Figure 4A , 4B The examples are basically the same as those in 5A, except that... Figure 5B In this example, the uncoated portion 124 may be arranged partially around the circumference of the lead 22, rather than completely around the circumference of the lead 22. The remaining portion of the circumference of the lead 22 (e.g., excluding the portion 124) may be coated with an electrically insulating material. Thus, the coated portion 123 may cover the portions of the respective defibrillator electrode 122 near and away from the uncoated portion 124, as well as the remaining portion of the circumference of the lead 22 excluding the uncoated portion 124.

[0102] Figure 6 This is a flowchart illustrating example operation of sensing electrical signals according to one or more techniques of this disclosure. For convenience, the IMD 12 and external device 38 in Figures 1-5 are shown. Figure 6 To describe. However, Figure 6 The technology can be performed by different components of the IMD 10 or by other or alternative medical devices.

[0103] In some instances, the IMD 12 may include a lead 22. The lead 22 may include a lead body with a curved shape. For example, the distal portion of the lead 22 may include one or more arcuate portions. The distal portion of the lead 22 may include two arcuate portions that together may resemble the Greek letter epsilon “ε”. In some instances, each defibrillator electrode 32 is carried by one of two corresponding arcuate portions of the distal portion of the lead body. The two arcuate portions extend or bend in the same direction away from the central axis of the distal portion of the lead 22. In some instances, a pacing / sensing electrode 36 may be arranged on the lead body such that the pacing / sensing electrode 36 is substantially aligned with the central axis. In such instances, the midpoint of the defibrillator electrode 32 is laterally offset from the pacing / sensing electrode 36. A corresponding uncoated portion 34 of the defibrillator electrode 32 may be located at or near the midpoint of the defibrillator electrode 32. Other examples of cardiovascular external leads comprising one or more defibrillation electrodes 32 and one or more pacing / sensing electrodes 36 carried by a curved (e.g., curved, meandering, wavy, or zigzag) distal portion of the lead 22 can also be implemented using the techniques described herein.

[0104] The processing circuitry 50 of the IMD 12 selects one or more sensing vectors from a non-parallel vector group (602). Furthermore, the processing circuitry 50 selects one or more therapy vectors from the non-parallel vector group (604). The non-parallel vector group may include a first vector, a second vector, and a third vector. In some instances, the first vector may include a first pacing / sensing electrode 36A and a second pacing / sensing electrode 36B, the second vector may include the first pacing / sensing electrode 36A and an uncoated portion 34, and the third vector may include the second pacing / sensing electrode 36B and an uncoated portion 34. The IMD 12 senses electrical signals and provides treatment via the selected vectors (606). For example, the sensing circuitry 52 of the IMD 12 can sense electrical signals based on one or more selected sensing vectors, and the signal generation circuitry 54 of the IMD 12 can deliver treatment based on one or more selected therapy vectors.

[0105] In block 608, processing circuitry 50 may determine whether to update the vector selection. For example, processing circuitry 50 may determine whether to update the vector selection based on one or more of the following: a vector update schedule, user input, detection of treatment effectiveness loss (e.g., loss of treatment capture), and detection of sensing effectiveness loss (e.g., detection of undersensitivity to cardiac depolarization). If processing circuitry 50 determines not to update the vector selection (the "No" branch of block 608), the example operation returns to block 606 and IMD 12 senses the electrical signal and delivers treatment via the selected vector. If processing circuitry 50 determines to update the vector selection (the "Yes" branch of block 608), the example operation returns to block 602, and processing circuitry 50 selects one or more sensing vectors from the non-parallel vector group, and processing circuitry 50 selects one or more treatment vectors from the non-parallel vector group.

[0106] The techniques described in this disclosure can be implemented, at least in part, in hardware, software, firmware, or any combination thereof. For example, aspects of these techniques can be implemented in one or more processors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic QRS circuit systems, and any combination of such components embodied in external devices (such as doctor or patient programmers, simulators, or other devices). The terms "processor" and "processing circuit system" can generally refer to any of the aforementioned logic circuit systems, alone or in combination with other logic circuit systems, or any other equivalent circuit system, alone or in combination with other digital or analog circuit systems.

[0107] For each aspect implemented in software, at least some of the functions of the systems and apparatus described in this disclosure can be embodied as instructions on a computer-readable storage medium, such as RAM, DRAM, SRAM, magnetic disk, optical disk, flash memory, or various forms of EPROM or EEPROM. The instructions can be executed to support one or more aspects of the functions described in this disclosure.

[0108] Additionally, in some aspects, the functions described herein can be housed within dedicated hardware and / or software modules. Describing different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be implemented by separate hardware or software components. Rather, the functions associated with one or more modules or units can be performed by separate hardware or software components, or integrated into shared or separate hardware or software components. Moreover, the techniques can be implemented entirely within one or more circuit or logic elements. The techniques disclosed herein can be implemented in a wide variety of devices or apparatuses comprising IMDs, external programmers, combinations of IMDs and external programmers, integrated circuits (ICs) or IC groups, and / or discrete circuit systems residing in IMDs and / or external programmers.

[0109] This disclosure includes several examples, some of which are provided below.

[0110] Example 17. A medical electrical lead comprising a lead body including a first curved portion and a second curved portion distal to the first curved portion; a first high-voltage electrode located on the first curved portion of the lead body, wherein the first high-voltage electrode includes at least one coated portion coated with an electrically insulating material configured to prevent conduction of a signal having a first voltage range between the first high-voltage electrode and patient tissue, and to allow conduction of a signal having a second voltage range between the first high-voltage electrode and patient tissue, wherein the first voltage range is lower than the second voltage range; a second high-voltage electrode located on the second curved portion of the lead body; and a low-voltage electrode assembly located on the lead body, the low-voltage electrode assembly including a first low-voltage electrode and a second low-voltage electrode distal to the first low-voltage electrode, wherein the first low-voltage electrode is located on the lead body proximal to the first high-voltage electrode, and wherein the second low-voltage electrode is located on the lead body between the first high-voltage electrode and the second high-voltage electrode.

[0111] Example 18. The medical electrical lead according to Example 17, wherein the first high-voltage electrode includes a proximal coated portion of one or more coated portions, a distal coated portion of one or more coated portions, and an uncoated portion between the proximal coated portion and the distal coated portion.

[0112] Example 19. The medical electrical lead according to Example 18, wherein the first high-voltage electrode is positioned on the first curved portion such that the first high-voltage electrode forms an arc, and wherein the uncoated portion is located at the peak of the arc.

[0113] Example 20. The medical electrical lead according to any one of Examples 17-19, wherein the entire surface area of ​​the first high-voltage electrode is coated with an electrically insulating material.

Claims

1. A medical electrical lead comprising: a lead body; a high voltage electrode located on the lead body, the high voltage electrode comprising a proximal coated portion, a distal coated portion, and an uncoated portion located between the proximal coated portion and the distal coated portion, wherein the proximal coated portion and the distal coated portion are coated with an electrically insulating material configured to prevent conduction of signals having a first voltage range between the high voltage electrode and patient tissue and to allow conduction of signals having a second voltage range between the high voltage electrode and patient tissue, wherein the first voltage range is lower than the second voltage range; and a low voltage electrode set located on the lead body, the low voltage electrode set comprising a first low voltage electrode and a second low voltage electrode distal to the first low voltage electrode, wherein the low voltage electrode set and the uncoated portion are positioned on the lead body such that: a first angle is formed between a first line passing through the first low voltage electrode and the second low voltage electrode and a second line passing through the first low voltage electrode and the uncoated portion, and a second angle is formed between the first line and a third line passing through the second low voltage electrode and the uncoated portion, wherein the first angle is in a range of thirty degrees to sixty degrees, and wherein the second angle is in a range of thirty degrees to sixty degrees.

2. The medical electrical lead of claim 1, wherein the electrically insulating material is tantalum pentoxide.

3. The medical electrical lead of any of claims 1-2, wherein the distal coated portion is located distal to the uncoated portion, wherein the proximal coated portion is located proximal to the uncoated portion, wherein the first low voltage electrode is located proximal to the proximal coated portion, and wherein the second low voltage electrode is distal to the distal coated portion.

4. The medical electrical lead of any of claims 1-2, wherein the lead body comprises a curved portion, wherein the high voltage electrode is located on the curved portion such that the high voltage electrode forms an arc, and wherein the uncoated portion is located at a peak of the arc.

5. The medical electrical lead of claim 4, wherein the first low voltage electrode is proximal to the arc, and wherein the second low voltage electrode is distal to the arc.

6. The medical electrical lead of any of claims 1-2, further comprising: a first electrical conductor disposed within the lead body, wherein a distal end of the first electrical conductor is coupled to the high voltage electrode and a proximal end of the first electrical conductor is configured to be coupled to a medical device; a second electrical conductor disposed within the lead body, wherein a distal end of the second electrical conductor is coupled to the first low voltage electrode and a proximal end of the second electrical conductor is configured to be coupled to the medical device; and a third electrical conductor disposed within the lead body, wherein a distal end of the third electrical conductor is coupled to the second low voltage electrode and a proximal end of the third electrical conductor is configured to be coupled to the medical device, wherein the medical electrical lead is configured to enable the medical device to perform at least one of: sense a first electrogram according to a first vector comprising the first low voltage electrode and the second low voltage electrode; ​ sensing a second electrogram according to a second vector that includes the first low voltage electrode and the uncoated portion; or sensing a third electrogram according to a third vector that includes the second low voltage electrode and the uncoated portion.

7. The medical electrical lead of claim 6, wherein the medical electrical lead is configured to enable the medical device to perform at least one of: deliver one or more pacing pulses according to the first vector via the first low voltage electrode and the second low voltage electrode; deliver one or more pacing pulses according to the second vector via the first low voltage electrode and the uncoated portion; or deliver one or more pacing pulses according to the third vector via the second low voltage electrode and the uncoated portion.

8. The medical electrical lead of any of claims 1-2, wherein the uncoated portion is disposed partially around a circumference of the lead body, a remainder of the circumference of the lead body being coated with the electrically insulative material.

9. The medical electrical lead of any of claims 1-2, wherein the high voltage electrode is a first high voltage electrode, the medical electrical lead further comprising: a second high voltage electrode on the lead body distal to the first high voltage electrode.

10. The medical electrical lead of claim 9, wherein the second high voltage electrode is not coated with the electrically insulative material.

11. The medical electrical lead of claim 9, wherein the proximal coated portion is a first proximal coated portion, wherein the distal coated portion is a first distal coated portion, wherein the uncoated portion is a first uncoated portion, wherein the second high voltage electrode includes a second proximal coated portion, a second distal coated portion, and a second uncoated portion between the second proximal coated portion and the second distal coated portion, wherein the second proximal coated portion and the second distal coated portion are coated with the electrically insulative material, wherein the low voltage electrode set further includes a third low voltage electrode distal to the second low voltage electrode, and wherein the low voltage electrode set and the second uncoated portion are located on the lead body such that: a third angle is formed between a fourth line passing through the second low voltage electrode and the third low voltage electrode and a fifth line passing through the second low voltage electrode and the second uncoated portion, and a fourth angle is formed between the fourth line and a sixth line passing through the third low voltage electrode and the second uncoated portion.

12. The medical electrical lead of any of claims 1-2, wherein the proximal coated portion and the distal coated portion are configured to prevent transmission of pacing pulses and are configured to allow transmission of defibrillation shocks, and wherein the uncoated portion is configured to transmit at least one of a defibrillation shock, a pacing pulse, and sense an electrical signal corresponding to a cardiac depolarization.

13. A medical device system comprising: the medical electrical lead of any of claims 1-12; and a medical device including a sensing circuit electrically coupled to the medical electrical lead, wherein the sensing circuit is configured to one or more of: sense a first electrogram according to a first vector that includes the first low voltage electrode and the second low voltage electrode; sensing a second electrogram according to a second vector comprising the first low voltage electrode and the uncoated portion; or sensing a third electrogram according to a third vector comprising the second low voltage electrode and the uncoated portion.

14. The medical device system of claim 13, wherein the medical device further comprises a stimulation generation circuit configured to at least one of: deliver one or more pacing pulses according to the first vector via the first low voltage electrode and the second low voltage electrode; deliver one or more pacing pulses according to the second vector via the first low voltage electrode and the uncoated portion; or deliver one or more pacing pulses according to the third vector via the second low voltage electrode and the uncoated portion. ​

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