Implantable medical lead implanting tool

Abstract

A medical device system includes an implantable medical lead including a lead body defining a proximal end and a distal portion, and at least a portion of the distal portion of the lead body defining a contoured configuration. The medical device system also includes an introducer tool defining a lumen configured to receive the distal portion, and the introducer tool configured to limit rotation of the distal portion within the lumen.

Description

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 366,743, filed on June 21, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to implantable medical leads, and more particularly to techniques for implanting implantable medical leads. Background Art

[0003] Malignant tachyarrhythmias, such as ventricular fibrillation (VF), are uncoordinated contractions of the myocardium of the ventricles in the heart and are the most common arrhythmias in cardiac arrest patients. If such arrhythmias persist for more than a few seconds, cardiogenic shock and cessation of effective blood circulation may result. As a result, sudden cardiac death (SCD) may occur within minutes.

[0004] In patients at high risk for VF, the use of implantable systems, such as implantable cardioverter-defibrillator (ICD) systems, has been shown to be beneficial in preventing SCD. Implantable systems, such as pacemakers with or without cardioversion or defibrillation capabilities, can also treat other cardiac dysfunctions, such as bradycardia and heart failure. Such implantable systems may include an electrical device configured to deliver therapy via electrodes. Therapy may include electric shocks and / or anti-tachycardia pacing (ATP). Implantable systems may also be configured to deliver cardiac pacing, for example to treat bradyarrhythmias or for cardiac resynchronization therapy (CRT).

[0005] The implantable system may include one or more implantable medical leads. The distal portion of the implantable medical lead may include one or more electrodes and may be positioned at a target location within the patient's body for delivering electrical therapy and / or electrical sensing via the electrodes. The proximal end of the lead may be coupled to the implantable system. The implantable system may also include one or more housing electrodes, sometimes referred to as can electrodes, for delivering therapy and / or sensing.

[0006] Due to the inherent surgical risks of attaching and replacing implantable medical leads directly in or on the heart, subcutaneous implantable systems have been designed, in which the implantable system and leads are located under the skin outside the thorax. It has also been proposed that the distal portion of the lead of the implantable system can be implanted in the thorax, but not in contact with the heart, for example, under the sternum. Additionally, it has been proposed to implant the distal portion of the lead of the implantable system in an extracardiac vessel within the thorax, such as the internal thoracic vein (ITV), intercostal veins, superior epigastric vein or azygos vein, hemiazygos vein, and accessory hemiazygos vein.

[0007] Implantable medical leads are also used to deliver therapy to tissues other than the heart. Implantable medical leads can be used to position one or more electrodes in or near a target nerve, muscle, or organ to deliver electrical stimulation to such tissue. As an example, an implantable medical lead can be positioned in the epidural space to deliver spinal cord stimulation, or positioned near other nerves such as the pelvic nerves or renal nerves to deliver neurostimulation to the nerves. Summary of the invention

[0008] Using electrodes of extravascular or other extracardiac leads to deliver pacing pulses or defibrillation may require higher energy levels to capture and / or defibrillate the heart relative to electrodes on or in the heart. The shape and / or positioning of the electrodes, or the lead body on which the electrodes are placed, may be selected to improve energy delivery to the heart while avoiding and / or reducing energy delivered to extracardiac tissues. The lead body and / or electrodes of an extravascular implantable cardioverter-defibrillator (EV-ICD) having a wavy shape, a serpentine shape, etc., may "flip" when the lead is deployed, for example, the electrodes and / or coils are oriented in the opposite direction to that intended during implantation. For example, an EV-ICD may be intended to implant a defibrillation electrode oriented toward the right side of the patient and a pacing electrode oriented toward the left side of the patient, and the EV-ICD lead may be "spiral" when advanced in the lumen of a conventional introducer tool so as to "flip" when deployed, for example, the defibrillation electrode is oriented toward the left side of the patient and the pacing electrode is oriented toward the right side of the patient.

[0009] The present disclosure describes implantable medical leads and implantable systems utilizing the leads, such as ICD systems. More specifically, the present disclosure describes a system including an introducer tool configured to limit the rotation of the lead during implantation. For example, a catheter may have a distal portion defining a lumen having a non-circular shape (e.g., rectangular, square, oval, etc.) configured to "lock" a portion of the lead in a preferred rotational orientation prior to implantation and allow a clinician to visually determine the orientation of the lead via imaging (e.g., fluoroscopy).

[0010] In one example, the present disclosure describes a medical device system comprising: an implantable medical lead comprising a lead body defining a proximal end and a distal portion, wherein at least a portion of the distal portion of the lead body defines a wavy configuration; and an introducer tool defining a lumen configured to receive the distal portion, wherein the guide tool is configured to limit rotation of the distal portion within the lumen.

[0011] In another example, the present disclosure describes a method comprising: positioning an introducer tool at an implantation location within a patient's body, wherein the introducer tool defines a lumen configured to receive a distal portion of an implantable medical lead, wherein the introducer tool is configured to limit rotation of the distal portion within the lumen; inserting the distal portion of the implantable medical lead into the lumen, wherein the implantable medical lead comprises a lead body defining a proximal end and a distal portion, wherein at least a portion of the distal portion of the lead body defines a wavy configuration; advancing the distal portion through the lumen to the implantation location; and expanding the distal portion at the implantation location into a wavy configuration and having a predetermined rotational orientation.

[0012] In another example, the present disclosure describes a medical device system comprising: an implantable medical lead comprising a lead body defining a proximal end and a distal portion, wherein at least a portion of the distal portion of the lead body defines a wavy configuration; and an introducer tool defining a non-circular lumen configured to receive the wavy configuration and lock the wavy configuration in a specific rotational orientation within the lumen.

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

[0014] Figure 1A is a front view of a patient with an extravascular ICD system including intrathoracic implanted leads.

[0015] Figure 1B is a side view of a patient with an extravascular ICD system with intrathoracic implanted leads.

[0016] Figure 1C is a lateral view of a patient with an extravascular ICD system with intrathoracic implanted leads.

[0017] Figure 2 is a conceptual diagram illustrating a distal portion of an example implantable medical lead deployed in a first rotational orientation.

[0018] Figure 3 is an example of unfolding in the second rotation orientation Figure 2 Conceptual illustration of the distal portion of an example implantable medical lead.

[0019] Figure 4is a conceptual cross-sectional view of a distal portion of an example implantable medical lead within the lumen of an example introducer tool.

[0020] Figure 5 is a conceptual cross-sectional view of a distal portion of an example implantable medical lead within the lumen of another example introducer tool.

[0021] Figure 6 is a conceptual cross-sectional view of an example dilator tool within the lumen of another example introducer tool.

[0022] Figure 7 is a flow chart illustrating an example technique for implanting an implantable medical lead via an example introducer tool.

[0023] Figure 8 is a functional block diagram of an example configuration of electronic components of an example ICD. DETAILED DESCRIPTION

[0024] As used herein, relational terms such as "first" and "second", "above" and "below", "front" and "back", etc. may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements.

[0025] Referring now to the drawings, in which like reference designators refer to like elements, Figures 1A to 1C 1 and 2. A conceptual diagram illustrating various views of an example extravascular implantable cardioverter-defibrillator (ICD) system 8 is shown in FIG. The ICD system 8 includes an ICD 9 connected to implantable medical leads 10 and a separate implantable shield 30. Figure 1A is a front view of a patient 12 having an extravascular ICD system 8 implanted therein. Figure 1B is a side view of a patient 12 having an extravascular ICD system 8 implanted therein. Figure 1C is a lateral view of a patient 12 having an extravascular ICD system 8 implanted therein.

[0026] ICD 9 may include an outer shell that forms an airtight seal that protects the components of ICD 9. The outer shell of ICD 9 may be formed of a conductive material such as titanium or a titanium alloy, which may be used as an outer shell electrode (sometimes referred to as a can electrode). In some embodiments, ICD 9 may be formed to have or may include multiple electrodes on the outer shell. ICD 9 may also include a connector assembly (also referred to as a connector block or plug) that includes electrical feedthroughs through which electrical connections are made between conductors of lead 10 and electronic components included in the outer shell of ICD 9. As will be described in further detail herein, the outer shell may house one or more processors, memories, transmitters, receivers, sensors, sensing circuits, treatment circuits, power supplies, and other suitable components. The outer shell is configured to be implanted in a patient (such as patient 12).

[0027] In the example shown, the ICD 9 is implanted outside the left thorax of the patient, e.g., under the skin and outside the chest cavity (subcutaneous or submuscular). In some cases, the ICD 9 may be implanted between the left posterior axillary line and the left anterior axillary line of the patient. However, as described later, the ICD 9 may be implanted in other extrathoracic locations of the patient.

[0028] Lead 10 may include an elongated lead body 13 having a distal portion 16 sized to be implanted in an extravascular location proximal to the heart, such as within the thorax (eg, Figures 1A to 1C For example, lead 10 may extend from ICD 9 toward the center of the patient's torso, e.g., toward the patient's xiphoid process 23, under the skin and outside the chest cavity (e.g., subcutaneously or submuscularly) to outside the chest. At a location near xiphoid process 23, lead body 13 may be bent or otherwise rotated upward and extended. The bend may be preformed and / or lead body 13 may be flexible to facilitate the bend. Figures 1A to 1C In the example illustrated in , the lead body 13 extends upward within the thorax below the sternum in a direction substantially parallel to the sternum.

[0029] In one example, the distal portion 16 of the lead 10 may be located in a substernal position such that the distal portion 16 of the lead 10 extends substantially upward along the posterior side of the sternum within the anterior mediastinum 36, as shown in FIG. Figure 1C . The anterior mediastinum 36 can be considered to be bounded laterally by the pleura 39, posteriorly by the pericardium 38, and anteriorly by the sternum 22. In some cases, the anterior wall of the anterior mediastinum 36 may also be formed by the transverse thoracic muscle and one or more costal cartilages. The anterior mediastinum 36 includes a large amount of loose connective tissue (such as cellulite), adipose tissue, some lymphatic vessels, lymph glands, substernal muscle tissue (e.g., transverse chest muscles), thymic body, branches of the internal thoracic artery, and the ITV.

[0030] In another example, the lead body 13 may extend upwardly outside the thorax (rather than inside the thorax), for example, subcutaneously or submuscularly above the thorax / sternum. The lead 10 may be implanted at other locations, such as above the sternum, offset to the right of the sternum, angled laterally from the proximal or distal end of the sternum, etc. In other examples, the lead 10 may be implanted in an extracardiac vessel within the thorax, such as the ITV, intercostal veins, superior epigastric veins or the azygos, hemiazygos, and accessory hemiazygos veins. In some examples, the orientation of the distal portion 16 of the lead 10 may be different from Figures 1A to 1C , such as orthogonal to or otherwise transverse to the sternum 22 and / or inferior to the heart 26. In such examples, the distal portion 16 of the lead 10 can be at least partially within the anterior mediastinum 36.

[0031] The lead body 13 may have a generally tubular or cylindrical shape and may define a diameter of approximately 3-9 French (Fr). However, lead bodies less than 3 Fr and greater than 9 Fr may also be utilized. In another configuration, the lead body 13 may have a flat, ribbon-like or paddle-like shape along at least a portion of the length of the lead body 13, with a solid woven filament or metal mesh structure. In such examples, the width across the lead body 13 may be between 1 mm and 3.5 mm. Other lead body designs may be used without departing from the scope of the present application.

[0032] The lead body 13 may be formed of a non-conductive material including silicone, polyurethane, fluoropolymer, mixtures thereof, and other suitable materials, and shaped to form one or more cavities (not shown), however, the technology is not limited to such configurations. The distal portion 16 may be manufactured to be biased in a desired configuration, or alternatively, may be manipulated by a user into a desired configuration. For example, the distal portion 16 may be constructed of a ductile material so that the user can manipulate the distal portion into a desired configuration that remains unchanged until manipulated into a different configuration.

[0033] The lead body 13 may include a proximal end 14 and a distal portion 16, which includes an electrode configured to deliver electrical energy to the heart or sense electrical signals of the heart. The distal portion 16 can be anchored to a desired location in the patient's body, such as under the sternum or subcutaneously, by, for example, suturing the distal portion 16 to the patient's muscle tissue, tissue or bone at the xiphoid process entry site. In some examples, the distal portion 16 can be anchored to the patient or by using rigid tines, prongs, barbs, clips, screws and / or other protruding elements or flanges, discs, compliant tines, flaps, porous structures such as mesh elements, and metal or non-metal stents that promote tissue growth for engagement, bioadhesive surfaces and / or any other non-piercing elements.

[0034] The lead body 13 may define a substantially linear portion 20 ( Figure 1A ).like Figure 1A As shown, at least a portion of the distal portion 16 can define a wavy configuration distal to the substantially linear portion 20. In particular, the distal portion 16 can define a wavy pattern, such as a sawtooth, zigzag, sinusoidal, serpentine, or other pattern, as it extends toward the distal end of the lead 10. In other configurations, the lead body 13 may not have a substantially linear portion 20 as it extends upward, but may begin the wavy configuration immediately after the bend.

[0035] The distal portion 16 includes one or more defibrillation electrodes configured to deliver an anti-tachyarrhythmia, such as cardioversion / defibrillation, electric shock to the heart 26 of the patient 12. In some examples, the distal portion 16 includes a plurality of defibrillation electrodes spaced a distance apart from one another along the length of the distal portion 16. Figures 1A to 1C In the illustrated example, the distal portion 16 includes two defibrillation electrodes 28a and 28b (collectively referred to as “defibrillation electrodes 28 ”).

[0036] The defibrillation electrodes 28 may be disposed around or within the lead body 13 of the distal portion 16, or alternatively, may be embedded within the wall of the lead body 13. In one configuration, the defibrillation electrodes 28 may be coil electrodes formed of a conductor. The conductor may be formed of one or more conductive polymers, ceramics, metal-polymer composites, semiconductors, metals, or metal alloys, including but not limited to one of platinum, tantalum, titanium, niobium, zirconium, ruthenium, indium, gold, palladium, iron, zinc, silver, nickel, aluminum, molybdenum, stainless steel, MP35N, carbon, copper, polyaniline, polypyrrole, and other polymer combinations. In another configuration, each of the defibrillation electrodes 28 may be a flat ribbon electrode, a paddle electrode, a braided or woven electrode, a mesh electrode, a directional electrode, a patch electrode, or another type of electrode configured to deliver a cardioversion / defibrillation shock to the heart 26 of the patient 12.

[0037] In one configuration, the defibrillation electrodes 28 are spaced approximately 0.25 cm-4.5 cm apart, and in some cases 1 cm-3 cm apart from each other. In another configuration, the defibrillation electrodes 28 are spaced approximately 0.25 cm-1.5 cm apart from each other. In yet another configuration, the defibrillation electrodes 28 are spaced approximately 1.5 cm-4.5 cm apart from each other.

[0038] exist Figures 1A to 1CIn the configuration shown, the defibrillation electrodes 28 span a substantial portion of the distal portion 16. Each of the defibrillation electrodes 28 may have a length between about 1 cm-10 cm, a length between about 2 cm-6 cm, or a length between about 3 cm-5 cm. However, according to the technology of the present disclosure, lengths greater than 10 cm and less than 1 cm may be utilized. The total length of the defibrillation electrodes on the distal portion 16, such as the length of the two defibrillation electrodes 28 combined, may vary according to a number of variables. In one example, the total length may be between about 5 cm-10 cm. However, in other embodiments, the defibrillation electrodes 28 may have a total length less than 5 cm and greater than 10 cm. In some cases, the defibrillation electrodes 28 may have substantially the same length, or alternatively, different lengths.

[0039] The defibrillation electrodes 28 may be electrically connected to one or more conductors that may be disposed in a body wall of the lead body 13 or in one or more insulating lumens (not shown) defined by the lead body 13. In an example configuration, each of the defibrillation electrodes 28 is connected to a common conductor so that a voltage may be applied to all of the defibrillation electrodes 28 simultaneously to deliver an anti-tachyarrhythmia shock to the heart 26. In other configurations, the defibrillation electrodes 28 may be attached to separate conductors so that each defibrillation electrode 28 may have a voltage applied to it independently of the other defibrillation electrodes 28. In such a case, the ICD 9 or lead 10 may include one or more switches or other mechanisms to electrically connect the defibrillation electrodes together to serve as common polarity electrodes so that, in addition to being able to apply voltage independently, a voltage may be applied to all of the defibrillation electrodes 28 simultaneously.

[0040] The distal portion 16 may also include one or more pacing and / or sensing electrodes configured to deliver pacing pulses to the heart 26 and / or sense electrical activity of the heart 26. Such electrodes may be referred to as pacing electrodes, sensing electrodes, or pacing / sensing electrodes. Figures 1A to 1C In the illustrated example, the distal portion 16 includes two pacing / sensing electrodes 32a and 32b (collectively referred to as “pacing / sensing electrodes 32 ”).

[0041] In the illustrated example, the pace / sense electrode 32b is positioned between the defibrillation electrodes 28, e.g., within a gap between the defibrillation electrodes, and the pace / sense electrode 32a is positioned closer to the proximal defibrillation electrode 28a along the distal portion 16. In some examples, there may be more than one electrode 32 within a gap between the defibrillation electrodes 28. In some examples, the electrode 32 is additionally or alternatively located distally of the distal-most defibrillation electrode 28b.

[0042] In one example, the distance between the nearest defibrillation electrode 28 and the electrode 32 is greater than or equal to about 2 mm and less than or equal to about 1.5 cm. In another example, the electrode 32 may be spaced greater than or equal to 5 mm and less than or equal to 1 cm from the nearest one of the defibrillation electrodes 28. In yet another example, the electrode 32 may be spaced greater than or equal to 6 mm and less than or equal to 8 mm from the nearest one of the defibrillation electrodes 28.

[0043] The electrodes 32 may be configured to deliver low voltage electrical pulses to the heart or may sense cardiac electrical activity, such as depolarization and repolarization of the heart. Therefore, the electrodes 32 may be referred to herein as pacing / sensing electrodes 32. In one configuration, the electrodes 32 are ring electrodes. However, in other configurations, the electrodes 32 may be any of a variety of different types of electrodes, including ring electrodes, short coil electrodes, paddle electrodes, hemispherical electrodes, or directional electrodes. Each electrode in the electrodes 32 may be an electrode of the same or different type as another electrode in the electrodes 32. The electrodes 32 may be electrically isolated from the adjacent defibrillation electrodes 28 by including an electrically insulating layer of material between the electrodes 32 and the adjacent defibrillation electrodes 28. Each electrode 32 may have its own separate conductor so that a voltage may be applied to each electrode or sensed via each electrode independently of the other electrodes 32.

[0044] Electrode 28 is referred to as a defibrillation electrode, and electrode 32 is referred to as a pacing / sensing electrode, because they may have different physical structures, thereby achieving different functions. Defibrillation electrode 28 may be larger than pacing / sensing electrode 32, for example, having a larger surface area, and thus may be configured to deliver an anti-tachyarrhythmia shock having a relatively higher voltage than a pacing pulse. The relatively smaller size of pacing / sensing electrode 32 may provide advantages over defibrillation electrodes for delivering pacing pulses and sensing intrinsic cardiac activity, for example, a lower pacing capture threshold and / or better sensing signal quality. However, defibrillation electrode 28, such as in combination with pacing / sensing electrode 32, may be used to deliver pacing pulses and / or sense electrical activity of the heart.

[0045] exist Figures 1A to 1C In the illustrated configuration, each electrode 32 is substantially aligned along a primary longitudinal axis ("x"). In one example, the primary longitudinal axis is defined by a portion of the elongated body 13 (e.g., the substantially linear portion 20). In another example, the primary longitudinal axis is defined relative to the patient's body, for example, along the anterior midline (or midsternal line), one of the sternal lines (or lateral sternal line), the left parasternal line, or other lines.

[0046] In one configuration, the midpoint of each electrode 32a and 32b is along the primary longitudinal axis "x" such that when the distal portion is implanted in a patient, each electrode 32a and 32b is disposed at at least substantially the same horizontal location. In some examples, the longitudinal axis "x" may correspond to the caudocranial axis of the patient, and a horizontal axis orthogonal to the longitudinal axis "x" may correspond to the mediolateral axis of the patient. In other configurations, the electrodes 32 may be disposed at any longitudinal or horizontal location along the distal portion 16 disposed between, proximal to, or distal to the defibrillation electrodes 28. Figure 1A In the example illustrated in , the electrode 32 is disposed along the wavy configuration of the distal portion 16 at a location closer to the heart 26 of the patient 12 than the defibrillation electrode 28 (e.g., at the peak of the wavy configuration toward the left side of the sternum). Figure 1A As illustrated in , for example, the electrodes 32 are substantially aligned with each other along the left sternal line. Figure 1A In the example illustrated in , the defibrillation electrode 28 is arranged along the peak of a wave-like configuration extending away from the heart toward the right side of the sternum. This configuration places the pacing / sensing electrode 32 closer to the heart than the electrode 28 to facilitate cardiac pacing and sensing at relatively low amplitudes.

[0047] In some examples, when the distal portion 16 is implanted outside a blood vessel, the pacing / sensing electrodes 32 and the defibrillation electrodes 28 may be disposed in a common plane. In other configurations, the wavy configuration may not be substantially disposed in a common plane. For example, the distal portion 16 may define a concavity or curvature.

[0048] The proximal end 14 of the lead body 13 may include one or more connectors 34 to electrically couple the lead 10 to the ICD 9. The ICD 9 may also include a connector assembly including electrical feedthroughs through which electrical connections are made between the one or more connectors 34 of the lead 10 and the electronic components included in the housing. The housing of the ICD 9 may house one or more processors, memories, transmitters, receivers, sensors, sensing circuits, treatment circuits, power sources (capacitors and batteries), and / or other components. The components of the ICD 9 may generate and deliver electrical therapy, such as anti-tachycardia pacing, cardioversion or defibrillation shocks, post-shock pacing, and / or bradycardia pacing.

[0049] The wavy configuration of distal portion 16 and the inclusion of electrodes 32 between defibrillation electrodes 28 provide multiple therapy vectors for delivering electrical therapy to the heart. For example, at least a portion of defibrillation electrodes 28 and one of electrodes 32 may be disposed over the right ventricle or any chamber of the heart so that pacing pulses and anti-tachyarrhythmia shocks may be delivered to the heart. The housing of ICD 9 may be charged or used as a polarity different from the polarity of one or more defibrillation electrodes 28 and / or electrodes 32 so that electrical energy may be delivered to the heart between the housing and defibrillation electrodes 28 and / or electrodes 32.

[0050] When voltage is applied to each defibrillation electrode 28, each defibrillation electrode may have the same polarity as each other defibrillation electrode 28 so that a defibrillation shock may be delivered together from all defibrillation shocks. In examples where the defibrillation electrodes 28 are electrically connected to a common conductor within the lead body 13, this is the only configuration for defibrillation electrodes 28. However, in other examples, the defibrillation electrodes 28 may be coupled to separate conductors within the lead body 13, and therefore may each have a different polarity, so that electrical energy may flow between the defibrillation electrodes 28, or between one of the defibrillation electrodes 28 and one of the pacing / sensing electrodes 32 or housing electrodes, to provide an anti-tachyarrhythmia shock, pacing therapy, and / or sense cardiac depolarization. In this case, the defibrillation electrodes 28 may still be electrically coupled together, for example, via one or more switches within the ICD 9, to have the same polarity.

[0051] In some examples, the ICD system 8 may optionally include one or more shields 30. The shield 30 may be configured to be implanted in the patient 12 separately from the implanted lead 10 and / or the distal portion 16 of the lead 10, or implanted together with the implanted lead 10 and / or the distal portion 16. The shield 30 may have various shapes, for example, circular, oval, bean-shaped, balloon-shaped, etc. The shield 30 may be configured to block the electric field from delivering electrical therapy via the electrode, for example, from pacing pulses and / or anti-tachyarrhythmia shocks, in a direction away from the electrode from the heart (for example, in a forward direction). In this way, the shield 30 may reduce the likelihood that the electric field will stimulate extracardiac tissues such as sensory nerves or motor nerves. In addition, the shield 30 may direct the electric field toward the heart, thereby allowing a pacing pulse of the heart to be captured at a lower energy level and / or an anti-tachyarrhythmia shock at a lower energy level than the energy level that may be required without the shield 30. Lower energy pacing pulses may also reduce the likelihood that pacing pulses delivered via pacing electrodes or defibrillation pulses delivered via defibrillation electrodes 28 will stimulate extracardiac tissue, and may result in less power consumption by the ICD 9, and thus extend the useful life of the ICD. It should be understood that various aspects of the technology disclosed herein may be applied to implantable systems other than the ICD 9, including but not limited to bradycardia pacemaker systems. For example, a lead that does not include a defibrillation electrode 28 may include one or more shields 30 and may be used with a pacemaker system that does not have defibrillation capability.

[0052] In the example shown, shield 30 is implanted in the pleural cavity of patient 12 (e.g., bounded laterally by pleura 39, posteriorly by pericardium 38, and anteriorly by sternum 22) and positioned anteriorly of distal portion 16. In some examples, shield 30 may be implanted such that at least a portion of shield 30 is positioned between the heart and a lung (or multiple lungs) of patient 12, e.g., between pericardium 38 and pleura 39 of patient 12.

[0053] In some examples, the distal portion 16 can be positioned at a substernal position via an introducer tool. For example, a clinician can form an incision 42 near the center of the trunk of the patient 12. The clinician can insert a dilator tool (e.g., a tunnel rod) into the lumen of the introducer tool, for example, to structurally support the introducer tool during the insertion of the introducer tool through the tissue of the patient 12. In some examples, the cross-sectional shape of the dilator tool can be similar to the cross-sectional shape of the lumen of the introducer tool, such as circular, oval, square, rectangular, polygonal or any suitable shape. In other examples, the introducer tool may include a flexible or semi-flexible material and / or be formed of a flexible or semi-flexible material (e.g., silicone, rubber, polymer, polyvinyl chloride, latex, Teflon, etc.), and the cross-sectional shape of the dilator tool may be different from the cross-sectional shape of the lumen of the introducer tool. For example, the dilator tool may have a circular cross-sectional shape, and when the dilator tool is located in the lumen, the lumen of the introducer tool is consistent with the circular cross-sectional shape. In some examples, the entire cross-sectional shape of the introducer tool may be consistent with the cross-sectional shape of the expander tool. The expander tool and the cross-sectional shape of the consistent introducer tool may help insert the introducer tool into the tissue through the patient 12, and / or help to subsequently advance the distal portion 16 through the lumen of the introducer tool to the target location, such as the target substernal position. For example, the clinician may insert the expander tool into the lumen of the introducer tool, thereby changing the shape of the lumen and the introducer tool to the shape of the expander tool, such as a circular cross-sectional shape. Then, the clinician may insert the introducer tool with the expander tool into the lumen through the patient's tissue, entering via incision 42. The clinician may then remove the expander tool, and the introducer tool and / or the lumen of the introducer tool may be relaxed to its preferred shape, such as an ellipse, square, rectangle, polygon, etc. In other examples, the introducer tool and / or the lumen are not consistent with the shape of the expander tool, and may have the same and / or different cross-sectional shapes as the expander tool.

[0054] The clinician can insert the introducer tool with the dilator tool through the tissue of the patient 12 and enter the substernal position via the incision 42, and advance the introducer tool upward along the sternum rear portion to form a substernal path 44 in the substernal position from the incision 42. Then, the clinician can remove the dilator tool and insert the distal portion 16 of the medical lead 10 into the substernal position through the lumen of the introducer tool. When being advanced through the lumen of the introducer tool, the wavy configuration of the distal portion 16 can be a relatively straight configuration. For example, the preformed or shaped wavy configuration of the distal portion 16 is flexible enough so that it is straightened when the guide wire passes through the lumen (or sheath, or channel, etc.) of the introducer tool. In some examples, the width of the lumen is less than (e.g., narrower than) the width of the wavy configuration of the distal portion 16. Once the distal portion is in place, the introducer tool is withdrawn toward the incision and removed from the patient's body, while the lead is left in place along the substernal path. As the introducer tool is withdrawn, the distal portion 16 assumes its pre-formed, corrugated configuration and, in examples including the shield 30 , the shield 30 may transition to the deployed configuration.

[0055] In some examples, the cross-sectional shape of the lumen of the introducer tool can allow the distal portion 16 to be at least partially in its wavy shape, thereby limiting the rotational movement of the distal portion 16 in the lumen. For example, when the distal portion 16 is advanced through the lumen with a circular cross-sectional shape, the distal portion 16 can be constrained by the lumen (for example, constrained by the width of the lumen) to be substantially straight. The circular cross-sectional shape of the lumen may not provide resistance (for example, except for the friction of the inner wall that limits the lumen) to the rotational movement of the distal portion 16, and the distal portion may "spiral" and / or rotate when being advanced through the lumen. In contrast, when the distal portion 16 is advanced through the lumen and / or when the introducer tool is removed from the patient's body to deploy the distal portion 16, for example, when the introducer tool is withdrawn from the medical lead 10 after the distal portion 16 is positioned at the target site under the sternum, the cross-sectional shape of the introducer tool is configured to prevent the rotational movement of the distal portion 16. For example, the expander tool may be configured to have a lumen having a cross-sectional shape having an internal range and / or distance that is not rotationally symmetric, such that the inner wall of the lumen contacts and prevents rotational movement of the distal portion 16 within the lumen, for example, a resistance (e.g., friction) greater than that of a lumen having a circular cross-sectional shape. The cross-sectional shape of the lumen may allow the distal portion 16 to at least partially expand / expand into an at least partially expanded / undulating structure in a specific and / or predetermined rotational orientation within the lumen, and the inner wall of the lumen may allow rotational movement of the distal portion 16 within the lumen, for example, in order to rotate within the lumen, the distal portion 16 needs to be straightened, or the cross-sectional shape of the lumen needs to be deformed. In other words, the introducer tool may be configured to limit rotation of the distal portion 16 within the lumen.

[0056] Once the distal portion 16 is positioned in the target substernal position, the clinician can withdraw the introducer tool toward the incision 42 to remove the introducer tool from the patient 12 while leaving the medical lead 10 in place along the substernal path 44. Then, as the distal portion 16 exits the introducer tool lumen, the distal portion can relax, expand, and / or otherwise change within the substernal position to assume its pre-formed wavy configuration, such as its deployed configuration. The clinician can insert and advance the distal portion 16 so that the pacing / sensing electrode 32 is in the wavy configuration when deployed, such that the wavy configuration pushes the pacing / sensing electrode 32 toward the left side of the sternum, rather than the defibrillation electrode 28.

[0057] In some examples, the introducer tool provides the benefit of preventing and / or reducing "lead flip," wherein the distal portion is delivered to a target substernal location and deployed into a wavy configuration with the defibrillation electrode 28 on the left side of the patient 12 and the pacing / sensing electrode 32 on the right side. For example, the introducer tool is configured to lock the rotational direction of the distal portion 16 to a predetermined rotational orientation during insertion of the distal portion 16, such that the distal portion 16 can be deployed in a predetermined and / or selected rotational orientation relative to the anatomy of the patient 12, e.g., such that the wavy configuration extends the pacing / sensing electrode 32 toward the left side of the sternum compared to the defibrillation electrode 28.

[0058] Figure 2 is a conceptual diagram illustrating a distal portion 16 of an example implantable medical lead 10 deployed in a first rotational orientation, and Figure 3 is a conceptual diagram illustrating a distal portion 16 of an example implantable medical lead 10 deployed in a second rotational orientation. In the example shown, the distal portion 16 is illustrated as viewed from the perspective of an observer facing the patient 12, such as looking in front of the patient 12. In the example shown Figure 2 The first rotational orientation can be a predetermined, “correct” and / or “un-reversed” rotational orientation in which the wavy configuration extends the pacing / sensing electrode 32 toward the left side of the sternal line A compared to the defibrillation electrode 28 (e.g., toward the right side of the sternal line A as viewed from the perspective of an observer facing the patient 12). Figure 3 The first rotational orientation can be an “incorrect” and / or “flipped” rotational orientation in which the wavy configuration extends the pacing / sensing electrode 32 toward the right side of the sternal line A compared to the defibrillation electrode 28 (e.g., from the perspective of an observer facing the patient 12, and toward the left side of the sternal line A).

[0059] like Figure 2 and Figure 3 As shown in , the wavy configuration of the distal portion 16 may include multiple peaks along the length of the distal portion. Figure 2In the illustrated example, the distal portion includes three peaks 24a, 24b, and 24c (collectively referred to as "peaks 24.") However, other configurations may include any number of peaks 24.

[0060] The wavy configuration may define a peak-to-peak distance 35 that may be variable or constant along the length of the distal portion 16. Figure 3 In the configuration illustrated in FIG. 1 , the wavy configuration defines a substantially sinusoidal configuration with a constant peak-to-peak distance 35 of approximately 2.0 cm to 6.0 cm. The wavy configuration may also define a peak-to-peak width 37, which may also be variable or constant along the length of the wavy configuration. Figure 3 In the illustrated configuration, the wavy configuration defines a substantially sinusoidal shape, with a constant peak-to-peak width 37 of approximately 0.25 cm to 3.0 cm. However, in other cases, the wavy configuration may define other shapes and / or patterns, such as an S-shape, a wave shape, etc.

[0061] The defibrillation electrode 28 may be disposed along, for example, or cover a substantial portion of the wavy configuration of the distal portion 16, for example, along at least 80% of the wavy portion. The defibrillation electrode 28 may extend along more or less than 80% of the wavy configuration. As another example, the defibrillation electrode 28 may extend along at least 90% of the wavy configuration.

[0062] The defibrillation electrode 28a extends along a substantial portion of the wavy configuration of the distal portion 16 from the proximal end to the peak 24b, for example, along a substantial portion of a first "wave" associated with the peak 24a, and the defibrillation electrode segment 28b extends along a substantial portion of the wavy configuration from the peak 24b to the distal end of the wavy configuration, for example, along a substantial portion of a second "wave" associated with the peak 24c. Figure 3 In the illustrated example, the portion of the wavy configuration on which the defibrillation electrode 28 is not disposed is the gap between the defibrillation electrodes 28a and 28b on the peak 24b where the electrode 32b is disposed.

[0063] like Figure 2 and Figure 3As illustrated, the distal portion 16 of the lead 10 may include a lead body portion 40a and a lead body portion 40b (collectively referred to as "lead body portion 40"), and a distal lead body portion 46. The lead body portion 40 extends between the pacing / sensing electrode 32b and the corresponding one of the defibrillation electrodes 28. The lead body portion 42 extends distally from the defibrillation electrode 28b. The lead body portion 40 may provide a relatively flat or smooth surface transition between the outer contour of the pacing / sensing electrode 32b and the outer contour of the defibrillation electrode 28. The conductors coupled to the electrodes 32b and 28b may extend through the lead body portion 40a, and the conductors coupled to the electrode 28b may extend through the lead body portion 40b. The lead body portions 40a and 40b and 42 may be formed of one or more polymers, which may be the same or different from the shield 30 and / or other portions of the lead body 13.

[0064] Figure 4 is a conceptual cross-sectional view of the distal portion 16 of the implantable medical lead 10 within the lumen 52 of an example introducer tool 50 . Figure 5 is a conceptual cross-sectional view of a distal portion of an example implantable medical lead within a lumen 62 of another example introducer tool 60. The introducer tool 50 may include an elongated body 54 defining the lumen 52 and configured to be inserted into a patient 12, e.g., in some examples using a dilator tool and in other examples without using a dilator tool. The introducer tool 60 may include an elongated body 64 defining the lumen 62 and configured to be inserted into a patient 12, e.g., in some examples using a dilator tool and in other examples without using a dilator tool. As shown, the elongated bodies 54 and 64 are elongated in the y-direction, e.g., having a major length in the y-direction, and Figure 4 and Figure 5 The cross-sectional views are respectively at the length position of the distal ends of the elongated bodies 54 and 64. In some examples, Figure 4 and Figure 5 These may be distal end views of elongated bodies 54 and 64, respectively.

[0065] In the example shown, the introducer tool 50 has an elliptical cross-sectional shape. For example, the elongated body 54 defines a lumen 52 having an elliptical shape and an outer surface having an elliptical shape. Although the outer surfaces of the lumen 52 and the elongated body 54 have the same shape (the size is different due to the thickness of the elongated body 54), in other examples, the cross-sectional shapes of the outer surfaces of the lumen 52 and the elongated body 54 may be different. For example, the introducer tool 60 has a circular cross-sectional shape, for example, the outer surface of the elongated body 64 defines a circular cross-sectional shape, and the lumen 62 has a square cross-sectional shape, for example, the elongated body 64 defines a square cross-sectional shape. Although the elongated body 54 defines a lumen 52 having an elliptical cross-sectional shape and the elongated body 64 defines a lumen 62 having a square cross-sectional shape, in other examples, the elongated bodies 54 and / or 64 may define a lumen having any other suitable cross-sectional shape, for example, a rectangle, a polygon, or any other cross-sectional shape having a non-circular and / or non-rotationally symmetric internal extent and / or distance (for example, in the xz plane shown) such that the inner walls of the lumens 52 and 62 contact and prevent rotational movement of the distal portion 16 within the lumens 52 and 62.

[0066] In some examples, the elongated body 54 and / or the elongated body 64 may be a flexible material, such as PVDF (polyvinylidene fluoride), nylon (polyamide), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), high-density polyethylene (HDPE), polycarbonate, silicone, plastic, polymer, etc. In the example shown, the elongated bodies 54 and 64 define lumens 52 and 62, respectively, which are configured to receive at least the distal portion 16 of the medical lead 10 and are configured to limit the rotation of the distal portion 16 within the respective lumens 52 and 62. For example, the elongated bodies 54 and 64 may have a certain hardness that is configured to straighten the wavy configuration of the distal portion 16 when the distal portion 16 is inserted into the lumen 52 or 62. In the illustrated example, the distal portion 16 is illustrated as being received and / or inserted into lumens 52 and 62, respectively, and the constrained peak-to-peak width 47 within the lumens 52 and 62 is less than the peak-to-peak width 37 of the distal portion 16 when deployed (e.g., unconstrained, unstraightened configuration). In the illustrated example, the cross-sectional shape of the lumens 52 and 62 is configured to allow the distal portion 16 to at least partially expand, for example, from a substantially straight configuration, to undulate within the lumens 52 and 62 along a particular rotational direction, for example, an x-direction among a plurality of rotational directions in the xz plane in the illustrated example, thereby limiting rotational movement of the distal portion 16. For example, if the lumen 52 or 62 constrains the distal portion 16 to be substantially straight, e.g., having a peak-to-peak width substantially the same as the diameter 49 of the tubular or cylindrical distal portion 16 (and / or lead body 13), the force limiting the rotational movement of the distal portion 16 within the lumens 52 and 62 may come solely from the friction between the inner surface of the elongated bodies 54 and 64 and the outer surface of the distal portion 16. In the example shown, the lumens 52 and 62 are configured to allow the distal portion 16 to at least partially undulate, e.g., constraining the distal portion 16 to have a peak-to-peak width 47 that is greater than the diameter 49, and in some examples less than the peak-to-peak width 37 of the fully expanded / deployed / undulated / unconstrained configuration. In addition, the cross-sectional shapes of the lumens 52 and 62 (e.g., elliptical and square, respectively) have different ranges and / or diameters depending on the rotational direction, and the force limiting the rotational movement of the distal portion 16 comes from both the friction between the inner surface of the slender bodies 54 and 64 and the outer surface of the distal portion 16, and the force required to straighten the distal portion 16 to allow rotational movement of the distal portion 16 (e.g., the slender bodies 54 and / or 64 prevent rotational movement of the distal portion 16 by reducing the allowable width of the distal portion 16 in certain rotational directions) or the force required to deform the slender bodies 54 and 64 to allow rotational movement of the distal portion 16.

[0067] In some examples, the introducer tools 50 and / or 60 may define lumens 52 and 62, respectively, for the proximal portion of the length of the introducer tools 50 and / or 60, and these lumens have a different cross-sectional shape, such as a circle (not shown), than the lumens 52 and 62, respectively, for the distal portion of the length of the introducer tools 50 and / or 60. For example, the clinician may form a path and / or tunnel through the tissue of the patient 12 via the incision 42 and insert and advance the distal portion 16 from the proximal portion of the length of the introducer tool 50 or 60 (within which the lumen 52 or 62 is configured to substantially straighten the distal portion 16) through the lumen 52 or 62 to the distal portion of the length of the introducer tool 50 or 60 (within which the lumen 52 or 62 is configured to allow the distal portion 16 to at least partially expand to at least partially undulate and "lock" the rotational orientation of the distal portion 16 relative to the introducer tool 50 or 60). The clinician can then insert and advance the introducer tool 50 or 60 to the target site while being able to control the rotational orientation of the introducer tool 50 or 60 and knowing the rotational orientation of the distal portion 16, and that the rotational orientation of the distal portion 16 will not change as the introducer tool 50 or 60 is advanced to the target substernal site / position. In some examples, whether the introducer tool 50 or 60 is "preloaded" with the distal portion 16 prior to insertion into the patient 12, or inserted into the patient 12 prior to inserting and advancing the distal portion 16 through the lumen 52 or 62, the introducer tools 50 and 60 can include one or more radiopaque markers 58 and / or 68 that are configured to indicate the rotational orientation of the introducer tools 50 and 60 within the patient 12.

[0068] In some examples, the medical devices and / or systems include the ICD system 8 , an introducer tool (eg, introducer tools 50 and / or 60 ), and a dilator tool 74 . Figure 6 yes Figure 4 6. Conceptual cross-sectional view of an example dilator tool 74 within lumen 62 of an example introducer tool 50. In some examples, dilator tool 74 can be used with introducer tool 50 or introducer tool 60 or any suitable introducer tool.

[0069] The dilator tool 74 can be configured to provide support and define the cross-sectional shape of the introducer tools 50 and / or 60, or to "penetrate" the tissue of the patient 12 in a cross-sectional shape, for example, in preparation for inserting the introducer tools 50 and / or 60. Figure 6 In the example shown, before the dilator tool 74 is inserted into the lumen 52, the introducer tool 50 may have an elliptical cross-sectional shape as described above, for example, Figure 652 and 62. The expander tool 74 is illustrated by the dashed oval cross-sectional shape of the elongated body 54 in the middle. In some examples, the expander tool 74 is configured to be received within the lumen and is configured to facilitate the insertion of the introducer tool into the patient, or the lumen 52 and the elongated body 54, and / or the lumen 62 and the elongated body 64 are configured to receive the expander within the lumen 52 and / or the lumen 62. For example, the expander tool 74 may include a material having a certain hardness that is configured to support the introducer tool 50 and / or 60 during insertion into the patient 12 and through the tissue of the patient 12 to position the introducer tool 50 and / or 60 to deliver the distal portion 16 to the target location (e.g., a substernal location) in the patient 12. In some examples, the expander tool 74 may have a cross-sectional shape that matches the cross-sectional shape of the lumen 52 or lumen 62, and is sized to be received within the lumen 52 and / or lumen 62, for example, substantially the same as or smaller than the size of the lumen 52 and / or lumen 62. In other examples, the expander tool 74 is configured to change the cross-sectional shape of the lumen 52 and / or lumen 62 when the expander tool 74 is inserted into the lumen 52 or lumen 62. For example, the elongated body 54 and / or 64 may include a flexible, compliant, and / or elastic material, and the expander tool 74 may have a greater hardness and / or rigidity than the elongated body 54 and / or 64, so that when inserted, the cross-sectional shape of the lumen 52 or 62 at least partially conforms to the cross-sectional shape of the expander tool 74. In some examples, the cross-sectional shape of the introducer tool 50 and / or 60, such as the cross-sectional shape of the outer surface of the elongated body 54 and / or 64, may at least partially conform to the shape of the expander tool 74. For example, the expander tool 74 can be configured to reduce trauma and / or damage to the tissue of the patient 12, for example, shaped to reduce damage to the patient 12 during insertion of the expander tool 74 and / or the introducer 50 or 60 into the patient 12. For example, the expander tool 74 can be configured to change the cross-sectional shape of the lumen 52 and the outer surface of the elongated body 54 when inserted into the lumen 52 to have a circular cross-sectional shape 55 (at Figure 6 1 and 12 ) and provide support for the elongated body 54 during insertion and passage through the tissue of the patient 12. In some examples, the dilator tool 74 can reduce the diameter of the introducer tool 50, such as in the x-direction in the example shown, to reduce the cross-sectional area of ​​the introducer / dilator tool inserted through the tissue of the patient 12.

[0070] In some examples, the introducer tool 50 and / or 60 is configured to restore its shape after the introducer tool 50 or 60 is inserted into the patient 12 and after the dilator tool 74 is removed from the lumen 52 or 62, respectively. For example, the elongated body 54 can be a flexible, compliant and / or elastic material that is configured to restore its shape. Figure 4The elliptical cross-sectional shape shown, and the elongated body 64 can be a flexible, compliant and / or elastic material configured to restore the circular cross-sectional shape of the outer surface of the elongated body 64 and the square cross-sectional shape of the lumen 62, as shown. Figure 5 shown.

[0071] Figure 7 is a flow chart illustrating an example technique for implanting a medical device including an implantable medical lead 10 . Figure 7 The invention is described with respect to implantable medical lead 10 and introducer tool 50. However, Figure 7 The example techniques may be used to implant other leads, shields, or introducer tools, such as introducer tool 60.

[0072] The clinician can position and / or insert the introducer tool 50 at the implantation location in the patient 12 (602). For example, the clinician can insert the dilator tool into the lumen 52 of the introducer tool 50. As described above, the dilator tool can be configured to change the cross-sectional shape of the lumen 52, for example, from an elliptical shape to a substantially circular cross-sectional shape, and / or the dilator tool can be configured to change the cross-sectional shape of the introducer tool 50 (e.g., the cross-sectional shape of the outer surface of the elongated body 54) from an elliptical shape to a substantially circular shape, and the elongated body 54 can be flexible, compliant and / or elastic, and is configured to receive the dilator tool and change the cross-sectional shape. In some examples, the clinician can then insert and / or position the introducer tool 50 at the implantation location in the patient 12 with the aid of the dilator tool. The clinician can then remove the dilator tool from the lumen 52 before inserting the distal portion 16 of the implantable medical lead 10 into the lumen 52, and the introducer tool 50 is configured to resume its shape (e.g., an elliptical shape) after the introducer tool 50 is inserted into the patient 12 and removed from the lumen 52.

[0073] In other examples, the introducer tool 50 can be inserted into the implantation site in the patient 12 without the dilator tool. For example, the elongated body 54 can have sufficient stiffness to enable the introducer tool 50 to be advanced through the incision 42 and the tissue of the patient 12 to the implantation site.

[0074] The clinician may insert 604 the distal portion 16 of the implantable medical lead 10 into the lumen 52. For example, the clinician may insert the distal portion 16 into the opening of the lumen 52 at the proximal end of the introducer tool 50, and the introducer tool 52 may straighten the distal portion 16, e.g., from its expanded wavy configuration to a substantially straighter insertion configuration, to be advanced through the lumen 52 to the implantation site.

[0075] The clinician may advance the distal portion 16 through the lumen 52 to the implantation location (606). For example, the clinician may move the distal portion 16 distally within the lumen 52, and the lumen 52 may limit the rotational movement of the distal portion 16 relative to the lumen 52 and / or the patient 12, for example, "locking" the rotational orientation of the distal portion 16 to a predetermined rotational orientation. In some examples, the clinician may rotate the introducer tool 50 to change the rotational orientation of the introducer tool 50 and the distal portion 16 locked relative to the lumen 52. In some examples, the introducer tool 50 may include one or more radiopaque markers configured to indicate the rotational orientation of the introducer tool 50 and / or the distal portion 16, and the clinician may rotate the introducer tool 50 based on the position of the one or more radiopaque markers before deploying the distal portion 16 into the wavy configuration, for example, so that the wavy configuration of the distal portion 16 is in a predetermined rotational orientation when deployed and / or exiting the lumen 52.

[0076] The clinician can deploy the distal portion 16 into a wavy configuration at a predetermined rotational orientation at the implantation location (608). For example, the clinician can withdraw and / or move the introducer tool 50 in a proximal end direction to release and / or cause the distal portion 16 to exit the lumen 52 at the implantation location and deploy into a wavy configuration oriented in a predetermined rotational orientation when exiting the lumen 52, for example, with the defibrillation electrode 28 oriented toward the right side of the patient and the pacing electrode 32 oriented toward the left side of the patient.

[0077] Figure 8 is a functional block diagram of an example configuration of electronic components and other components of ICD 9. ICD 9 includes processing circuitry 702, sensing circuitry 704, therapy delivery circuitry 706, sensor 708, communication circuitry 710, and memory 712. In other examples, ICD 9 may include more or fewer components. The described circuits and other components may be implemented together on shared hardware components, or separately as discrete but interoperable hardware or software components. The depiction of different features is intended to highlight different functional aspects and does not necessarily imply that such circuits and other components must be implemented by separate hardware or software components. Instead, the functions associated with one or more modules or circuits and components may be performed by separate hardware or software components, or integrated within shared or separate hardware or software components.

[0078] The sensing circuit 704 may be electrically coupled to some or all of the electrodes 716, which may correspond to any of the defibrillation electrodes, pacing / sensing electrodes, and housing electrodes described herein. The sensing circuit 704 is configured to obtain signals sensed via one or more combinations of the electrodes 716 and process the obtained signals.

[0079] The components of the sensing circuit 704 may be analog components, digital components, or a combination thereof. The sensing circuit 704 may, for example, include one or more sensing amplifiers, filters, rectifiers, threshold detectors, analog-to-digital converters (ADCs), and the like. The sensing circuit 704 may convert the sensed signal into digital form and provide the digital signal to the processing circuit 702 for processing or analysis. For example, the sensing circuit 704 may amplify the signal from the sensing electrode and convert the amplified signal into a multi-bit digital signal through the ADC. The sensing circuit 704 may also compare the processed signal with a threshold value to detect the presence of atrial depolarization or ventricular depolarization (e.g., a P wave or an R wave) and indicate the presence of atrial depolarization (e.g., a P wave) or ventricular depolarization (e.g., an R wave) to the processing circuit 702. Figure 8 As shown in , the ICD 9 may additionally include one or more sensors 708, such as one or more accelerometers, which may be configured to provide signals to the processing circuit 702 indicative of other parameters of the patient (such as activity or posture).

[0080] The processing circuit 702 may process signals from the sensing circuit 704 to monitor the electrical activity of the heart 26 of the patient 12. The processing circuit 702 may store the signals obtained by the sensing circuit 704 and any generated EGM waveforms, marker channel data, or other data derived based on the sensed signals in the memory 712. The processing circuit 702 may analyze the EGM waveforms and / or marker channel data to detect arrhythmias (e.g., bradycardia or tachycardia). In response to detecting a cardiac event, the processing circuit 702 may control the therapy delivery circuit 706 to deliver a desired therapy to treat the cardiac event, such as a defibrillation shock, a cardioversion shock, ATP, post-shock pacing, or bradycardia pacing.

[0081] The therapy delivery circuit 706 is configured to generate electrical therapy and deliver the electrical therapy to the heart 26. The therapy delivery circuit 706 may include one or more pulse generators, capacitors, and / or other components capable of generating and / or storing energy for delivery as pacing therapy, defibrillation therapy, cardioversion therapy, cardiac resynchronization therapy, other therapy, or a combination of therapies. In some cases, the therapy delivery circuit 706 may include a first set of components configured to provide pacing therapy and a second set of components configured to provide defibrillation therapy. In other cases, the therapy delivery circuit 706 may utilize the same set of components to provide both pacing therapy and defibrillation therapy. In still other cases, the therapy delivery circuit 706 may share some of the defibrillation therapy components and the pacing therapy components, while using other components only for defibrillation or pacing. The processing circuit 702 may control the therapy delivery circuit 706 to deliver the generated therapy to the heart 26 via one or more combinations of electrodes 716. Although Figure 8Not shown, but ICD 9 may include switching circuitry that may be configured by processing circuitry 702 to control which of electrodes 716 is connected to therapy delivery circuitry 706 and sensing circuitry 704.

[0082] The communication circuit 710 includes any suitable hardware, firmware, software, or any combination thereof for communicating with another device, such as a clinician programmer, a patient monitoring device, etc. For example, the communication circuit 710 may include appropriate modulation components, demodulation components, frequency conversion components, filtering components, and amplifier components for transmitting and receiving data via an antenna.

[0083] The various components of ICD 9 may include any one or more processors, controllers, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or equivalent discrete or integrated circuits, including analog circuits, digital circuits, or logic circuits. Processing circuitry 702 may include fixed function circuitry and / or programmable processing circuitry. The functions attributed to processing circuitry 702 herein may be embodied in software, firmware, hardware, or any combination thereof.

[0084] The memory 712 may include computer readable instructions that, when executed by the processing circuit 702 or other components of the ICD 9, cause one or more components of the ICD 9 to perform various functions attributed to those components in the present disclosure. The memory 712 may include any volatile, nonvolatile, magnetic, optical, or electronic media, such as random access memory (RAM), read-only memory (ROM), nonvolatile RAM (NVRAM), static nonvolatile RAM (SRAM), electrically erasable programmable ROM (EEPROM), flash memory, or any other nonvolatile computer readable storage medium.

[0085] In some examples, the distal portion of the lead may be oriented orthogonal to or otherwise transverse to the sternum and / or below the heart, rather than extending in an upward direction along the sternum. In such examples, according to any of the examples described herein, the lead may include one or more shields that cover a portion of the outer surface of one or more electrodes, such as a forward and / or downward portion. One or more such shields may block the electric field in a direction away from the heart, which may be a forward and / or downward direction.

[0086] It should be understood by those skilled in the art that the present application is not limited to the contents specifically shown and described above. In addition, unless otherwise indicated above, it should be noted that all drawings are not drawn to scale. Without departing from the scope and spirit of the present application, various modifications and variations are possible according to the above teachings, and the scope and spirit of the present application are limited only by the appended claims.

[0087] The following examples are a non-limiting list of clauses in accordance with one or more techniques of the present disclosure.

[0088] Embodiment 1. A medical device system, comprising: an implantable medical lead, the implantable medical lead comprising: a lead body, the lead body defining a proximal end and a distal portion, wherein at least a portion of the distal portion of the lead body defines a wavy configuration; and an introducer tool, the introducer tool defining a lumen, the lumen being configured to receive the distal portion, wherein the guide tool is configured to limit rotation of the distal portion within the lumen.

[0089] Embodiment 2. The medical device system according to embodiment 1, wherein the cross-sectional shape of the lumen is at least one of a rectangle, a square, or an ellipse.

[0090] Example 3. A medical device system according to Example 2, wherein the lumen has a circular cross-sectional shape at the proximal end of the guide tool, and has at least one of a rectangular cross-sectional shape, a square cross-sectional shape, or an elliptical cross-sectional shape at the distal portion of the guide tool.

[0091] Embodiment 4. The medical device system of any one of Embodiments 1 to 3, wherein the cross-sectional shape of the lumen is configured to limit rotation of the distal portion within the lumen.

[0092] Example 5. A medical device system according to any one of Examples 1 to 4, wherein the introducer tool is configured to straighten the wavy configuration of the distal portion when the distal portion is inserted into the lumen, wherein the cross-sectional shape of the lumen is configured to allow the distal portion to at least partially expand to undulate in a specific rotational direction within the lumen, thereby limiting rotational movement of the distal portion, and wherein a first width of the lumen is smaller than a second width of the distal portion of the lead body.

[0093] Example 6. According to any one of Examples 1 to 5, the medical device system further includes a dilator tool configured to be received within the lumen and configured to assist in inserting the introducer tool into the patient's body.

[0094] Example 7. The medical device system of Example 6, wherein the introducer tool comprises a flexible material, wherein the dilator tool is configured to change the cross-sectional shape of the lumen when the dilator tool is inserted into the lumen. Example 8. The medical device system of any one of Examples 6 or 7, wherein the introducer tool is configured to restore the shape of the introducer tool after the introducer tool is inserted into the patient and the dilator tool is removed from the lumen.

[0095] Example 9. A medical device system according to any one of Examples 1 to 8, wherein the introducer tool includes a radiopaque marker, the radiopaque marker being configured to indicate a rotational orientation of the introducer tool within the patient. Example 10. A medical device system according to any one of Examples 1 to 9, wherein the implantable medical lead further includes: a first defibrillation electrode and a second defibrillation electrode disposed along the wavy configuration, the first defibrillation electrode and the second defibrillation electrode being configured to deliver an anti-tachyarrhythmia shock; and a pacing electrode, the pacing electrode being configured to deliver a pacing pulse, the pacing pulse generating an electric field near the pacing electrode.

[0096] Embodiment 11. A method, the method comprising: positioning an introducer tool at an implantation location within a patient, wherein the introducer tool defines a lumen configured to receive a distal portion of an implantable medical lead, wherein the introducer tool is configured to limit rotation of the distal portion within the lumen;

[0097] Inserting the distal portion of the implantable medical lead into the lumen, wherein the implantable medical lead includes a lead body, the lead body defining a proximal end and a distal portion, wherein at least a portion of the distal portion of the lead body defines a wavy configuration; advancing the distal portion through the lumen to the implantation location; and unfolding the distal portion at the implantation location into the wavy configuration and having a predetermined rotational orientation.

[0098] Example 12. The method according to Example 11, further comprising: before expanding the distal portion into the wavy configuration at the implantation position, rotating the introducer tool so that the wavy configuration is in the predetermined rotational orientation.

[0099] Embodiment 13. The method of any one of Embodiment 11 or Embodiment 12, wherein the cross-sectional shape of the lumen is at least one of a rectangle, a square, or an ellipse. Embodiment 14. The method of any one of Embodiments 11 to 13, wherein the cross-sectional shape of the lumen is configured to limit rotation of the distal portion within the lumen.

[0100] Example 15. A method according to any one of Examples 11 to 14, wherein the guide tool is configured to straighten the wavy configuration of the distal portion when the distal portion is inserted into the lumen, wherein the cross-sectional shape of the lumen is configured to allow the distal portion to at least partially expand to undulate in a specific rotational direction within the lumen, thereby limiting the rotational movement of the wavy configuration.

[0101] Example 16. A method according to any one of Examples 11 to 15, wherein the guide tool comprises a flexible material, the method further comprising: inserting the expander tool into the lumen, wherein inserting the expander tool into the lumen changes the shape of the lumen into a substantially circular cross-sectional shape, wherein the guide tool is positioned at the implantation position in the patient's body with the aid of the expander tool.

[0102] Example 17. A method according to any one of Examples 11 to 16, further comprising: removing the dilator tool from the lumen before inserting the distal portion of the implantable medical lead into the lumen, wherein the introducer tool is configured to restore the shape of the introducer tool when the introducer tool is inserted into the patient's body and after the dilator tool is removed from the lumen.

[0103] Example 18. A method according to any one of Examples 11 to 17, wherein the guide tool includes a radiopaque marker, and the radiopaque marker is configured to indicate the rotational orientation of the guide tool within the patient's body.

[0104] Embodiment 19. A medical device system, the medical device system comprising: an implantable medical lead, the implantable medical lead comprising a lead body, the lead body defining a proximal end and a distal portion, wherein at least a portion of the distal portion of the lead body defines a wavy configuration; and an introducer tool, the introducer tool defining a non-circular lumen, the non-circular lumen being configured to receive the wavy configuration and lock the wavy configuration in a specific rotational orientation within the lumen.

[0105] Embodiment 20. The medical device system of Embodiment 19, wherein the cross-sectional shape of the non-circular lumen is at least one of a rectangle, a square, or an ellipse.

[0106] Embodiment 21. The medical device system according to any one of Embodiment 19 or Embodiment 20,

[0107] The introducer tool comprises a flexible material, and the medical device system further comprises an expander tool, which is configured to be received within the lumen and to change the cross-sectional shape of the lumen into a circular cross-sectional shape, wherein the circular cross-sectional shape is configured to reduce displacement of the patient's tissue during insertion of the introducer tool.

[0108] Example 22. A medical device system according to any one of Examples 19 to 21, wherein the introducer tool includes a radiopaque marker, and the radiopaque marker is configured to indicate the rotational orientation of the introducer tool within the patient's body.

Claims

1. A medical device system, comprising: An implantable medical lead comprising: a lead body defining a proximal end and a distal portion, wherein at least a portion of the distal portion of the lead body defines a wavy configuration; and An introducer tool defines a lumen configured to receive the distal portion, wherein the introducer tool is configured to limit rotation of the distal portion within the lumen. 2 . The medical device system of claim 1 , wherein a cross-sectional shape of the lumen is at least one of a rectangle, a square, or an ellipse.

3. A medical device system according to claim 2, wherein the lumen has a circular cross-sectional shape at the proximal end of the introducer tool, and has at least one of a rectangular cross-sectional shape, a square cross-sectional shape, or an elliptical cross-sectional shape at the distal portion of the introducer tool.

4. The medical device system of any one of claims 1 to 3, wherein the cross-sectional shape of the lumen is configured to limit rotation of the distal portion within the lumen.

5. A medical device system according to any one of claims 1 to 4, wherein the introducer tool is configured to straighten the wavy configuration of the distal portion when the distal portion is inserted into the lumen, wherein the cross-sectional shape of the lumen is configured to allow the distal portion to at least partially expand to undulate in a specific rotational direction within the lumen, thereby limiting rotational movement of the distal portion, and wherein a first width of the lumen is less than a second width of the distal portion of the lead body.

6. The medical device system of any one of claims 1 to 5, further comprising a dilator tool configured to be received within the lumen and configured to assist in inserting the introducer tool into a patient's body.

7. The medical device system of claim 6, wherein the introducer tool comprises a flexible material, wherein the dilator tool is configured to change the cross-sectional shape of the lumen when the dilator tool is inserted into the lumen.

8. A medical device system according to claim 6 or claim 7, wherein the introducer tool is configured to restore its shape after the introducer tool is inserted into the patient's body and the dilator tool is removed from the lumen.

9. The medical device system of any one of claims 1 to 8, wherein the introducer tool comprises a radiopaque marker configured to indicate a rotational orientation of the introducer tool within the patient's body.

10. The medical device system according to any one of claims 1 to 9, wherein the implantable medical lead further comprises: a first defibrillation electrode and a second defibrillation electrode disposed along the undulating configuration, the first defibrillation electrode and the second defibrillation electrode configured to deliver an anti-tachyarrhythmia shock; and a pacing electrode configured to deliver pacing pulses that generate an electric field near the pacing electrode.

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