Implantable medical lead assembly and implantable medical lead

Abstract

The invention refers to a lead assembly for an implantable medical lead for subthoracic / parasternal implantation. For effective defibrillation, pacing and / or sensing, the lead assembly comprises a base portion and an electrode section extending distally from the base portion, wherein the electrode section comprises a first leaf-shaped element, a second leaf-shaped element and at least one third leaf-shaped element, wherein in an implanted state each one of the first leaf-shaped element, the second leaf-shaped element and the at least one third leaf-shaped element project from the distal end segment of the base portion such that each two adjacent leaf-shaped elements of the first, second and at least one third leaf-shaped elements protrude from each other at an individual pre-defined angle, wherein the first leaf-shaped element comprises a first electrode member, the second leaf-shaped element comprises a second electrode member and at least one third leaf-shaped element comprises a third electrode member.

Description

[0001] Applicant: BIOTRONIK SE & Co. KG

[0002] Date: 18.11.2025

[0003] Our Reference: 24.123P-WO

[0004] Implantable medical lead assembly and implantable medical lead

[0005] The invention generally relates to an implantable medical lead assembly and an implantable medical lead comprising such a medical lead assembly.

[0006] Medical leads implanted in a patient’s body for electrical cardioversion, pacing or defibrillation of the heart are generally known in the art. In particular, electrically conducting leads may be implanted in or about the heart to reverse (i.e., defibrillate or cardiovert) certain life-threatening arrhythmias or to stimulate contraction (pacing) of the heart. Electrical energy is transmitted from a pulse generator which is electrically connected to the lead. Such transmitted electrical energy is applied to the heart via the lead to return the heart to normal rhythm or to stimulate the heart. Leads have also been used to sense conditions, materials or events (generally referred to as "sense" or "sensing") in the body, such as electrical potential in the atrium or ventricle of the heart. For that such medical lead may be connected to a sensing device using a connector assembly at the proximal end of the medical lead. Alternatively, the sensed signals may be transmitted to and processed by the pulse generator, and, for example, used for pacing control.

[0007] Medical leads represent the electrical link between the pulse generator and the patient’ s body tissue which is to be treated or sensed. Accordingly, the medical lead must be reliably mechanically and electrically connected to the patient’s body tissue at a pre-defined target location.

[0008] Most of the known pacemakers and defibrillators are implanted as transvenous systems. For example, defibrillators are mostly implanted in the left upper chest area, from where one or more leads are then guided through veins to the heart of the respective patient. However, such transvenous systems sometimes cause complications such as venous thrombosis or injury.

[0009] As an alternative to transvenous systems, a substemal system may be used, particularly in the treatment of potentially life-threatening arrhythmias such as ventricular tachycardia and ventricular fibrillation. The term “substemal systems” refers to the placement of a defibrillator in which the lead is not inserted into the heart transvenously (i.e. via a vein) as usual, but is instead placed sub-thoracic / parasternal, i.e. between the breastbone (sternum) and the heart.

[0010] In parasternal defibrillation, a lead is inserted under the sternum during a minimally invasive operation. This lead lies directly at the pericardium (the outer layer of the heart), but outside the heart and the great vessels. Placement under the sternum enables direct but extracardiac (outside the heart) stimulation.

[0011] A known medical lead for the parasternal defibrillation technique of Atacor Medical Inc. comprises a two-winged distal electrode tip (Atacor EV-ICD Lead System) for implantation between the rips and pericardium. It has the disadvantage that injuries can be caused by the two "tips" of the two-winged lead when the lead body is advanced, which can lead to complications (haemorrhages, perforation of the lungs, etc.) since the two wings of the lead are directly unfolded during introduction into the patient’s body. Additionally, direct unfolding positions the known system often too far from the pericardium to provide effective pacing, defibrillation and / or sensing.

[0012] Against this background, it is an objective of the present invention to enable atraumatic implanting of a parasternal lead and fixing it securely and over a long time within the patient’s body at a pre-defined target position for effective pacing, sensing and / or defibrillation.

[0013] The above objective is solved by an implantable medical lead assembly having the features of claim 1 and an implantable medical lead having the features of claim 13. Further, a respective implantation method is provided.

[0014] 24.123P-WO / 18.11.2025 In particular, the above objective is solved by an implantable medical lead assembly for an implantable medical lead comprising a base portion, in particular an elongated base portion, and an electrode section extending distally from the base portion, wherein the electrode section comprises a first web-shaped element, a second web-shaped element and at least one third web-shaped element, wherein in an implanted state each one of the first web-shaped element, the second web-shaped element and the at least one third web-shaped element project from the distal end segment of the base portion such that each two adjacent webshaped elements of the first, second and at least one third web-shaped elements protrude from each other at an individual pre-defined angle, wherein the first web-shaped element comprises a first electrode member, the second web-shaped element comprises a second electrode member and at least one third web-shaped element comprises a third electrode member.

[0015] The term “web-shaped” mentioned above and below may be replaced with the term “leafshaped,” so that the implantable medical lead assembly comprises leaf-shaped elements. These elements may extend in a star-like configuration from a common central point.

[0016] The electrode lead assembly may form a distal end section of an implantable medical lead. Regarding the electrode lead assembly, an elongated base portion of the above implantable electrode lead assembly forms the proximal end section of the electrode lead assembly. The longitudinal direction of the base portion is the direction having the greatest dimension. The base portion may comprise a cylindrical outer shape or at least sectionwise or fully a cylindrical outer shape, wherein its axial direction is referred to as longitudinal direction. In one embodiment, the base portion comprises an electrically insulating outer layer and an internal lumen configured to provide space for at least one electrically conducting member for electrically connecting the first, second and / or third electrode member. The base portion may form the distal end section of a lead cable that mechanically and electrically connects a connector of the medical lead to the web-shaped elements carrying the electrode members as indicated below in more detail.

[0017] 24.123P-WO / 18.11.2025 The electrode section extends distally from the base portion. The electrode section comprises a first web-shaped element, a second web-shaped element and at least one third web-shaped element, for example three web-shaped elements, four web-shaped elements or five webshaped elements. Accordingly, the group of web-shaped elements formed by the first webshaped element, the second web-shaped element and the at least one third web-shaped element are generally referred to as web-shaped elements in the following. Each web-shaped element has a web shape with an approximately round or flatted cross-sectional shape. Each web-shaped element may have an electrically insulating outer layer (except in the section of the electrode member) that may form a continuation of the outer layer of the base portion. Additionally, they may have an inner lumen for guiding electrical conductors at least over a section of the respective web-shaped element. The first web-shaped element, the second web-shaped element and the at least one third web-shaped element project in longitudinal direction from the most distal end segment of the base portion such that each two adjacent web-shaped elements of the first, second and at least one third web-shaped elements protrude from each other at an individual pre-defined angle. Accordingly, each two adjacent webshaped elements spread from one another in a tripod-like or multi-pod manner, wherein the spreading apart of the web-shaped elements is widely. The individual pre-defined angle of all pairs of adjacent web-shaped elements may be approximately similar or different. The angle of at least one of the pairs of adjacent web-shaped elements of the first web-shaped element and the second web-shaped element and the at least one third web-shaped element in the plane spanned by the adjacent web-shaped elements is, for example, not more than 150 °, e.g. not more than 130°. The furthest distal end of each web-shaped element may end in an atraumatic, e.g. round, tip. At their proximal end the outer shape of all web-shaped elements may correspond to the outer shape of the distal end segment of the base portion. For example, at the distal end of the base portion, the base portion splits into at least three web-shaped elements forming a transition section, wherein the inner lumen of the base portion is continued from and connected to all inner lumens of the web-shaped elements extending from the base portion. The outer shape of the first web-shaped element and / or the second web-shaped element and the at least one third web-shaped element may be formed as a continuous transition from its proximal end outer shape to its distal end outer shape.

[0018] 24.123P-WO / 18.11.2025 Each one of the first web-shaped element, the second web-shaped element and the at least one second web-shaped element comprises an electrode member for sub-thoracic / parasternal and extracardiac stimulation, defibrillation and / or sensing at its outer surface. I.e., the first web-shaped element comprises a first electrode member, the second webshaped element comprises a second electrode member and at least one third web-shaped element comprises a third electrode member. The spreading of the first web-shaped element, the second web-shaped element and the at least one third web-shaped element allows an excellent compensation of the anatomic variations of the patient since the web-shaped elements cover a great area of the heart’s outer surface. Further, the web-shaped elements are located over positions of the heart’s outer surface that are fully different but not too far away so that a particular pacing, stimulation and / or sensing position(s) may be selected according to the patient’s specific needs. Thereby the pacing effectivity, stimulation effectivity and / or sensing results can be improved.

[0019] In one embodiment, the first web-shaped element comprises at least one first supplemental electrode member and / or the second web-shaped element comprises at least one second supplemental electrode member and / or the at least one third web-shaped element comprises at least one third supplemental electrode member. Accordingly, the first web-shaped element comprises at least two electrodes and / or the second web-shaped element comprises at least two electrodes and / or the third web-shaped element comprises at least two electrodes for pacing, sensing and / or defibrillation. Three or four electrodes at each web-shaped element are possible, as well. The respective web-shaped element and the respective associated supplemental electrode member, e.g. the first web-shaped element and the first supplemental electrode member, have a pre-defined distance in longitudinal direction of the web-shaped element, for example, at least 10mm. Thereby, for example, combined defibrillation and / or sensing and / or pacing may be realized. Additionally or alternatively, the supplemental electrode member may form the counter electrode of the adjacent electrode member located at the same web-shaped element. In a further embodiment, the housing of the pulse generator that provides the pacing or stimulation signals for the electrode members and supplemental electrode members may form the counter electrode.

[0020] 24.123P-WO / 18.11.2025 In one embodiment of the lead assembly, the first electrode member, if applicable, the first supplemental electrode member, the second electrode member, if applicable, the second supplemental electrode member, the at least one third electrode member, if applicable, the at least one third supplemental electrode member is configured as any electrode type of a defibrillator type electrode, a stimulation type electrode and a sensing type electrode in a first electrical state. The defibrillator type electrode may comprise a helical (spiral) electrode element, whereas the stimulation type electrode and the sensing type electrode may comprise an annular (i.e. ring-like) electrode element or an electrode element shaped as an annular segment or patch, wherein each electrode element is an electrically conducting element located at or within the outer surface of the respective web-shaped element.

[0021] In one embodiment of the lead assembly, in a second electrical state the first electrode member and / or, if applicable, the first supplemental electrode member, and / or the second electrode member and / or if applicable, the second supplemental electrode member, and / or the at least one third electrode member and / or if applicable, the third supplemental electrode member, is configured as a different electrode type compared to the first electrical state, wherein the electrode type is any one of a stimulation type electrode and a sensing type electrode. Accordingly, a combined defibrillation / stimulation or pacing / sensing or defibrillation / sensing operation of the implantable medical lead assembly is possible.

[0022] In one embodiment of the lead assembly, at least two electrode members of the first electrode member, if applicable, one first supplemental electrode member, the second electrode member, if applicable, one second supplemental electrode member, the at least one third electrode member, if applicable one third supplemental electrode member that form a defibrillator electrode are electrically connected to each other in such way that they are at equal electrical potential. Accordingly, at least two electrode members or supplemental electrode members, e.g. three electrode members or supplemental electrode members at the at least three web-shaped elements are at equal electrical potential. This means that the respective, at least two electrode members are electrically connected and are electrically connected to the same signal supply line (i.e. pulse supply line) that is also connected to the pulse generator. In such configuration a defibrillation covering a great area of the patient’s heart can be achieved.

[0023] 24.123P-WO / 18.11.2025 In one embodiment of the lead assembly, at least two electrode members of the first electrode member, if applicable, the first supplemental electrode member, the second electrode member, if applicable, the second supplemental electrode member, the at least one third electrode member, if applicable, the at least one third supplemental electrode member that form a stimulation electrode are configured in such way that they are at the different electrical potential. In this configuration, a pacing (and / or sensing) may be provided by the lead assembly at a specific position of the heart’s outer surface. This configuration is realized, for example, by a separate connection of the respective, at least two electrode members to an individual signal supply line (i.e. pulse supply line). In other words, each one of the at least two electrode members has its own signal supply line, wherein each signal supply line is connected to the pulse generator. Each one of the at least two electrode members may be separately controlled or regulated.

[0024] In one embodiment, the aforementioned signal or pulse supply lines may extend through and are guided by the inner lumen of the base portion and the web-shaped elements of the implantable medical lead assembly.

[0025] In one embodiment of the lead assembly, the first web-shaped element and / or the second web-shaped element and / or the at least one third web-shaped element has an arcuate shape. In one embodiment, the arcuate shape of two of the first web-shaped element and the second web-shaped element and the at least one third web-shaped element is similar, wherein, in one embodiment, all web-shaped elements having an arcuate shape may have the same or a similar curvature direction. The arcuate (curved) shape of the web-shaped elements allows a better encompassing of the patient’s heart thereby increasing the stimulation or defibrillation effectivity of the electrodes located at the respective web-shaped elements providing a similar distance of the respective web-shaped element (and thereby its electrode members) along a great section of its full length. In one embodiment, a stimulation type electrode of the respective web-shaped element having an arcuate shape may be positioned at an extremum position (i.e. maximum or minimum) along the curved outer surface of the respective web-shaped element. In one embodiment, a stimulation type electrode may be located at a position where the respective web-shaped element has its greatest curvature.

[0026] 24.123P-WO / 18.11.2025 The length of each web-shaped element of the first web-shaped element, the second webshaped element and the at least one third web-shaped element in their respective longitudinal direction may be, for example, between 2 cm and 12 cm, e.g. between 3 cm and 8 cm. The length of an electrode member or a supplemental electrode member may be, e.g. between 1 mm and 60 mm.

[0027] In one embodiment of the lead assembly, the assembly comprises a spreading member configured to disconnect and spread the initially connected and / or close-fitted at least two web-shaped elements of the first web-shaped element and the second web-shaped element and the at least one third web-shaped element at a desired time point, for example at the end of the implantation process. An advantage of the late spreading is that the initially connected and / or close-fitted and thereby approximately parallelly extending at least two web-shaped elements may be implanted less traumatically at a pre-defined target position due to its overall narrower shape. Accordingly, it may be implanted into a greater depth within the patient’s body, e.g. into a position that is located between the left lung and the pericardium of the heart. For example, once the target position (in particular, the target depth within the patient’s body) of the implantable medical lead assembly is reached, the spreading member may be moved by the health care practitioner (HCP) to disconnect and spread the at least two web-shaped elements by means of, e.g. a wire-like element connected to the proximal end of the spreading member. After spreading, the adjacent web-shaped elements protrude from each other at the individual pre-defined angle. The spreading member may be located initially at the distal end of the at least two web-shaped elements to disconnect and spread. For example, the spreading member may comprise an atraumatic tip at its distal end, e.g. a spherical section. Additionally, the spreading member may be connected, e.g. at its proximal end, to a wire-like element extending through the initially connected and / or close-fitted, at least two web-shaped elements and the base portion to be moved by the HCP.

[0028] Alternatively, the web-shaped elements spread into their final position such that each two adjacent web-shaped elements of the first, second and at least one third web-shaped elements protrude from each other at an individual pre-defined angle prior, during or after

[0029] 24.123P-WO / 18.11.2025 implantation into the patient’s body. In this case, the spreading may be effected without a spreading member, for example by bending the web-shaped elements.

[0030] During implantation, the medical lead assembly is moved into the direction of the heart’s pericardium. The HCP may feel when the distal tip of the implantable medical lead assembly touches the pericardium due to the counterpressure provided by the pericardium. Thereby, the electrode members or supplemental electrode members may be placed near the pericardium thereby increasing the pacing / defibrillation / sensing effectivity depending on the function provided by the respective (supplemental) electrode member. For implantation in the initial state of the at least two web-shaped elements that are initially connected and / or close-fitted are, for example, a respective tool is used, e.g. a catheter.

[0031] In one embodiment of the lead assembly, the spreading member comprises a wedge or cone or pyramid configured to be moved such that the initially connected and / or close-fitted at least two web-shaped elements of the first web-shaped element and the second web-shaped element and the at least one third web-shaped element are disconnected and spread at a desired time point. The wedge and the pyramid may comprise base formed as an n-gone (n > 3), wherein the n-gone is simple and convex. The base of the cone may be circular or elliptical. In its initial position, the sharp and / or pointed end (apex) of the wedge or cone or pyramid may be located at the proximal end, whereas the greater end (base) opposite the sharp and / or pointed end may be located at the distal end of the implantable medical lead assembly. Due to its sharp and / or pointed end (apex) the spreading member of this embodiment may easily disconnect the at least two web-shaped elements as it is moved with the sharp and / or pointed end (apex) first and it cuts into the material of the at least two initially connected and / or close-fitted web-shaped elements like a knife or a chisel. The opposite, greater end of the spreading member effects spreading of the initially connected and / or close-fitted at least two web-shaped elements by displacing and pushing them apart.

[0032] In one embodiment of the lead assembly, the spreading member comprises or is made from biodegradable material, e.g. at least one material of the group comprising gelatine, collagens, alginates, starches, pectins or hydrocolloids. Further, the spreading member may have a

[0033] 24.123P-WO / 18.11.2025 compound shape comprising the wedged, pyramidal or conical shaped element and a semi- spherical shaped element.

[0034] In one embodiment of the lead assembly, the initially connected and / or close-fitted at least two web-shaped elements of the first web-shaped element and the second web-shaped element and the at least one third web-shaped element comprise a breaking groove. At the distal end face of three connected web-shaped elements, the breaking groove may have, e.g., the shape of a three-pointed star. The breaking groove reduces the force necessary for disconnection of the at least two web-shaped elements and specifies the position of separation of the initially connected and / or close-fitted at least two web-shaped elements thereby avoiding miscuts that would increase implantation costs and would make such implantation more harmful.

[0035] In one embodiment of the lead assembly, at least one of the first web-shaped element and the second web-shaped element and the at least one third web-shaped element comprises an anchoring element. Such anchoring element may be realized, for example, as a barb, a silicon or a polyurethane tine. The anchoring element may avoid dislocation and / or twisting of the respective at least one web-shaped element and thereby injuries during the lifetime of the lead assembly and the lead.

[0036] In one embodiment, the insulating layer of the proximal base section and the electrode section comprising the web-shaped element form an integral component that may be produced, for example, by injection molding. The material of the respective insulating layer may comprise or consist of at least one material of the group comprising silicone, thermoplastic polyurethane and liquid crystal polymer. The electrode members and supplemental electrode members may comprise or consist of at least one material of the group comprising stainless steel, platinum, gold and titanium.

[0037] The above objective is further solved by an implantable medical lead comprising the abovedescribed implantable medical lead assembly at its distal end. The above explained advantages and embodiments do also apply for the implantable medical lead comprising the

[0038] 24.123P-WO / 18.11.2025 implantable medical lead assembly. It is therefore referred to the above explanation in this regard.

[0039] In one embodiment of the lead, the lead comprises a connector at its proximal end configured to electrically connect the first electrode member and the second electrode member and the at least one third electrode member and, if applicable, the first supplemental electrode member, the second supplemental electrode member and the third supplemental electrode member to a pulse generator (via the respective electrical conductor extending along the medical lead), wherein the pulse generator provides the electrical signals that are transmitted to the respective electrode member for pacing and / or defibrillation. Additionally, sensed signals from the patient’s body, particularly from the heart, may be transmitted to the pulse generator or any other receiving device. For example, the connector is a 4-pole connector, e.g. a connector according to the DF4 standard.

[0040] The present invention will now be described in further detail with reference to the accompanying schematic drawings, wherein

[0041] Fig. 1 shows a first embodiment of an implantable medical lead with a first embodiment of an implantable medical lead assembly in a side view,

[0042] Fig. 2 depicts the distal end of a second embodiment of an implantable medical lead assembly in its initial state prior and during implantation,

[0043] Fig. 3 shows the distal end of the implantable medical lead assembly of Fig. 2 during spreading, and

[0044] Fig. 4 illustrates the final position of the web-shaped elements of the implantable medical lead assembly of Fig. 2 after spreading.

[0045] A first embodiment of an implantable medical lead 100 is shown in Fig. 1. The implantable medical lead 100 comprises a lead cable 135 extending in a longitudinal direction and a lead assembly 103 at its distal end. The lead assembly 103 comprises a first web-shaped element

[0046] 24.123P-WO / 18.11.2025 111, a second web-shaped element 112 and a third web-shaped element 113, wherein the web-shaped elements 111, 112, 113 with their electrode members 121, 122, 123 and supplemental electrode members 131, 132, 133 together form the electrode section. The web-shaped elements 111, 112, 113 extend from a (e.g. elongated) base portion 115 which forms a distal end section of a lead cable 135 of the medical lead 100. At the proximal end of the lead cable 135 a 4-pole connector 140 is located that may be configured to be plugged in a respective plug of a pulse generator (not shown). The pulse generator provides electrical signals for defibrillation, pacing and / or sensing of the patient’s heart (not shown).

[0047] The term “web-shaped” mentioned above and below may be replaced with the term “leafshaped,” so that the implantable medical lead assembly implantable medical lead 100 and / or the comprises leaf-shaped elements 111, 112, 113. These elements 111, 112, 113 may extend in a star-like configuration from a common central point.

[0048] The first web-shaped element 111 and the second web-shaped element 112 protrude distally and straight from the base portion 115 and protrude from each other at an angle of, e.g., 120°. The second web-shaped element 112 and the third web-shaped element 113 protrude distally and straight from the base portion 115 and protrude from each other at an angle of, e.g., 120°. The third web-shaped element 113 and the first web-shaped element 111 protrude distally and straight from the base portion 115 and protrude from each other at an angle of, e.g., 120°. Each web-shaped element 111, 112, 113 extends in a longitudinal direction, wherein the longitudinal direction each one of the respective web-shaped elements 111, 112, 113 is different and may be also different from the longitudinal direction of the lead cable 135.

[0049] Each web-shaped element 111, 112, 113 has a finger-like form, wherein the distal tip opposite the base portion 115 is atraumatically shaped (rounded tip). The outer surface of each web-shaped element 111, 112, 113 is formed by an electrically insulating layer (except where the (supplemental) electrode members are located). The first web-shaped element 111 supports a helical first electrode member 121 forming a defibrillation type electrode and a patch-like first supplemental electrode member 131 forming a pacing type electrode or a sensing type electrode. The first supplemental electrode member 131 is located distally from the first electrode member 121 at the electrically insulating outer surface of the first web-

[0050] 24.123P-WO / 18.11.2025 shaped element 111. The second web-shaped element 112 supports a helical second electrode member 122 forming a defibrillation type electrode and a patch-like second supplemental electrode member 132 forming a pacing type electrode or a sensing type electrode. The second supplemental electrode member 132 is located distally from the second electrode member 122 at the electrically insulating outer surface of the second webshaped element 112. The third web-shaped element 113 supports a helical third electrode member 123 forming a defibrillation type electrode and a patch-like third supplemental electrode member 133 forming a pacing type electrode or a sensing type electrode. The third supplemental electrode member 133 is located distally from the third electrode member 123 at the electrically insulating outer surface of the third web-shaped element 113.

[0051] The first web-shaped element 111, the second web-shaped element 112 and the third webshaped element 113 may have a longitudinal extension (i.e. longitudinal direction of the respective one of the first web-shaped element 111, the second web-shaped element 112 and the third web-shaped element 113) of, e.g., 3 cm to 7 cm. The helical first electrode member 121 of the first web-shaped element 111 may have a length (in the longitudinal direction of the first web-shaped element 111) of, e.g., 50 mm. The width of the first supplemental electrode member 131 may be, e.g., 3 mm. The distance between the first electrode member 121 and the first supplemental electrode member 131 (in the longitudinal direction of the first web-shaped element 111) is, for example, from 10mm to 40mm, in particular from 20mm to 30mm. The length of the second electrode member 122 and the length of the third electrode member 123 are similar to the length of the first electrode member 121. Accordingly, the width of the second supplemental electrode member 132 and the width of the third supplemental electrode member 133 are similar to the width of the first supplemental electrode member 131. Analogously, the distance between the second electrode member 122 and the second supplemental electrode member 132 (in the longitudinal direction of the second web-shaped element 112) as well as the distance between the third electrode member 123 and the third supplemental electrode member 133 (in the longitudinal direction of the third web-shaped element 113) is similar to the distance between the first electrode member 121 and the first supplemental electrode member 131 (in the longitudinal direction of the first web-shaped element 111).

[0052] 24.123P-WO / 18.11.2025 The first web-shaped element 111, the second web-shaped element 112 and the third webshaped element 113 may have an arcuate shape wherein the curvature may extend into the surface of the drawing of Fig. 1. Accordingly, the web-shaped elements 111, 112, 113 may encompass the patient’s heart once they are in the final position close to the pericardium.

[0053] The first electrode member 121, the second electrode member 122 and the third electrode member 123 are electrically connected to one defibrillation conductor extending within an inner lumen of the lead cable 135 from the connector 140 to the distal end of the lead cable 135. The distal section of the lead cable 135 forming the base portion 115 of the lead assembly transitions into the three web-shaped elements 111, 112, 113, each having an inner lumen. At the transition section from the base portion 115 to the web-shaped elements 111, 112, 113 the defibrillation conductor branches out into the inner lumen of each web-shaped element 111, 112, 113 such that it guides the defibrillation conductor to and electrically connects it to the respective electrode member 121, 122, 123. Accordingly, all defibrillation electrode elements 111, 112, 113 are at the same electric potential and provide a defibrillation signal at the same time. In contrast, each one of the first supplemental electrode member 131, the second supplemental electrode member 132 and the third supplemental electrode member 133 is connected to a separate pacing conductor extending within the inner lumen of the lead cable 135 and within the inner lumen of the respective web-shaped element 111, 112 or 113. Accordingly, the first supplemental electrode member 131, the second supplemental electrode member 132 and the third supplemental electrode member 133 may be separately controlled by the pulse generator. Accordingly, the connector 140 is a 4-pole connector, wherein three poles are used for the pacing and / or sensing electrode members 131, 132, 133 and the fourth pole is used for the three defibrillator electrodes 121, 122, 123.

[0054] Alternatively, the web-shaped elements 111, 112, 113 may comprise the defibrillator type electrodes 121, 122, 123 only or may comprise the supplemental electrodes 131, 132, 133 forming pacing and / or sensing type electrodes only. In a further alternative embodiment, for example, each web-shaped element 111, 112, 113 may comprise two supplemental electrodes 131, 132, 133 forming pacing and / or sensing type electrodes for multi-pole stimulation only.

[0055] 24.123P-WO / 18.11.2025 In this embodiment, the insulating layer of the web-shaped elements 111, 112, 113 and the base portion 115 of the electrode lead assembly 103 may be formed by an integral component as depicted in Fig. 1, for example, produced by injection molding. The integral component of the electrode lead assembly 103 is fixedly connected to the insulating layer of the lead cable 135, for example, by gluing or plastic welding at the proximal end of the base portion 115 such that it hermetically seals the inner lumen of the lead cable 135 and the electrode lead assembly 103.

[0056] The above described medical lead 100 is suitable for sub-thoracic / parasternal defibrillation, pacing and / or sensing of a patient’s heard. For that, the distal end of the medical lead 100 is introduced into a pre-defined position between the sternum and the heart. Due to the positioning of the at least three web-shaped elements such that they protrude from each other at an individual pre-defined angle and thereby covering a great outer area of the heart surface facing the medical lead, the medical lead can compensate for anatomical variations of different patients very well.

[0057] The second embodiment of an implantable medical lead assembly 215 shown in Fig. 2 to 4 differs from the first embodiment by the structure of the web-shaped elements. This embodiment similarly comprises a first web-shaped element 211, a second web-shaped element 212 and a third web-shaped element 213. However, the web-shaped elements 211, 212, 213 are initially close-fitted or connected to each other as depicted in Fig. 2. In Fig. 2 to 4 the electrode members and supplemental electrode members at the web-shaped elements 211, 212, 213 are not shown for better clarity. The electrode members and / or supplemental electrode members may have the same structure as the electrode members and supplemental electrode members of the first embodiment shown in or explained in connection with Fig. 1.

[0058] The medical lead assembly 215 further comprises a spreading member 220 having an integrated but compound structure with a pyramid and a semi-sphere. The pyramid has a rectangular base. The semi-spherical section is located distally from the rectangular base of the pyramid. The apex of the pyramid forms the proximal end of the spreading member 220 and is fixed to and connected with a wire-like element for moving (pulling) the spreading member 220. The extension of the wire-like element is indicated by the dotted line 230 which

[0059] 24.123P-WO / 18.11.2025 also represents the longitudinal axis of the group of web-shaped elements 211, 212, 213 in their initial position.

[0060] Fig. 2 shows the initial position of the spreading member 220 prior to and during implantation. It is located at and adjacently to the distal ends of the web-shaped elements 211, 212, 213, wherein the web-shaped elements 211, 212, 213 are connected or close-fitted. Once the medical lead assembly 215 is located at the pre-defined position between the sternum and the patient’s heart, the spreading member 220 is moved, for example by means of the wire-like element connected to the spreading member 220, such that the initially connected and / or close-fitted three web-shaped elements 211, 212, 213 are disconnected and spread. This is indicated in Fig. 3 by means of arrow 237 which depicts the pulling force pulling the wire-like element (represented by dotted line 230). For example, an HCP pulls the wire-like element. Accordingly, the spreading member 220 cuts into the center position between the three web-shaped elements 211, 212, 213 to disconnect and spread them. An intermediate position during movement of the spreading member 220 is visualized in Fig. 3, whereas Fig. 4 shows the final position after finishing movement of the spreading member 220. In this position, the web-shaped elements 211, 212, 213 are fully disconnected and spread such that adjacent pairs of web-shaped elements spread under a predefined angle. This embodiment, in particular, allows implantation of the lead assembly at a greater depth due to its narrow shape. The spreading of the web-shaped elements 211, 212, 213 is provided at a desired time point, e.g., when the web-shaped element 211, 212, 213 is in a suitable position for spreading to avoid injuries and to position the electrodes at the web-shaped elements 211, 212, 213 in a manner that effective pacing, defibrillation and / or sensing of the patient’s heart. A positioning in a greater depth and closer to the patient’s heart is advantageous to achieve a lower stimulation level.

[0061] 24.123P-WO / 18.11.2025

Claims

Claims1. An implantable medical lead assembly (103, 215) comprising a base portion (115) and an electrode section extending distally from the base portion (115), wherein the electrode section comprises a first leaf-shaped element (111, 211), a second leafshaped element (112, 212) and at least one third leaf-shaped element (113, 213), wherein in an implanted state each one of the first leaf-shaped element (111, 211), the second leaf-shaped element (112, 212) and the at least one third leaf-shaped element (113, 213) project from the distal end segment of the base portion (115) such that each two adjacent leaf-shaped elements of the first, second and at least one third leaf-shaped elements (111, 112, 113, 211, 212, 213) protrude from each other at an individual predefined angle, wherein the first leaf-shaped element (111, 211) comprises a first electrode member (121), the second leaf-shaped element (112, 212) comprises a second electrode member (122) and at least one third leaf-shaped element (113, 213) comprises a third electrode member (123).

2. The implantable medical lead assembly according to claim 1, wherein the first leaf- shaped element (111, 211) comprises at least one first supplemental electrode member (131) and / or the second leaf-shaped element (112, 212) comprises at least one second supplemental electrode member (132) and / or the at least one third leaf-shaped element (113, 213) comprises at least one third supplemental electrode member (133).

3. The implantable medical lead assembly according to any one of the previous claims, wherein the first electrode member (121), if applicable, the first supplemental electrode member (131), the second electrode member (122), if applicable, the second supplemental electrode member (132), the at least one third electrode member (123), if applicable, the at least one third supplemental electrode member (133) is configured as any electrode type of a defibrillator type electrode, a stimulation type electrode and a sensing type electrode in a first electrical state.

4. The implantable medical lead assembly according to claim 3, wherein in a second electrical state the first electrode member (121) and / or if applicable, the first24.123P-WO / 18.11.2025supplemental electrode member (131), and / or the second electrode member (122) and / or, if applicable, the second supplemental electrode member (132), and / or the at least one third electrode member (123) and / or, if applicable, the at least one third supplemental electrode member (133) is configured as a different electrode type than in the first electrical state, wherein the electrode type is any one of a stimulation type electrode and a sensing type electrode.

5. The implantable medical lead assembly according to any one of the previous claims, wherein at least two electrode members of the first electrode member (121), if applicable, one first supplemental electrode member (131), the second electrode member (122), if applicable, one second supplemental electrode member (132), the at least one third electrode member (123), if applicable one third supplemental electrode member (133) that form a defibrillator electrode are electrically connected to each other in such way that they are at equal electrical potential.

6. The implantable medical lead assembly according to any one of the previous claims, wherein at least two electrode members of the first electrode member (121), if applicable, the first supplemental electrode member (131), the second electrode member (122), if applicable, the second supplemental electrode member (132), the at least one third electrode member (123), if applicable the at least one third supplemental electrode member (133) that form a stimulation electrode are configured in such way that they are at the different electrical potential.

7. The implantable medical lead assembly according to any one of the previous claims, wherein the first leaf-shaped element (111, 211) and / or the second leaf-shaped element (112, 212) and / or the at least one third leaf-shaped element (113, 213) has an arcuate shape.

8. The implantable medical lead assembly according to any one of the previous claims, wherein the assembly comprises a spreading member (220) configured to disconnect and spread the initially connected and / or close-fitted at least two leaf-shaped elements24.123P-WO / 18.11.2025- 19 - of the first leaf-shaped element (111, 211) and the second leaf-shaped element (112, 212) and the at least one third leaf-shaped element (113, 213) at a desired time point.

9. The implantable medical lead assembly according to claim 8, wherein the spreading member (220) comprises a wedge or cone or pyramid configured to be moved such that the initially connected and / or close-fitted at least two leaf-shaped elements of the first leaf-shaped element (111, 211) and the second leaf-shaped element (112, 212) and the at least one third leaf-shaped element (113, 213) are disconnected and spread at a desired time point.

10. The implantable medical lead assembly according to any one of the claims 8 to 9, wherein the spreading member comprises biodegradable material.

11. The implantable medical lead assembly according to any one of the claims 8 to 10, wherein the initially connected and / or close-fitted at least two leaf-shaped elements of the first leaf-shaped element (111, 211) and the second leaf-shaped element (112, 212) and the at least one third leaf-shaped element (113, 213) comprise a breaking groove.

12. The implantable medical lead assembly according to any one of the previous claims, wherein at least one of the first leaf-shaped element (111, 211) and the second leafshaped element (112, 212) and the at least one third leaf-shaped element (113, 213) comprises an anchoring element.

13. An implantable medical lead (100) comprising the lead assembly (103, 215) according to any one of the previous claims at its distal end.

14. The implantable medical lead of claim 13, wherein the lead comprising a connector (140) at its proximal end configured to electrically connect the first electrode member (121) and the second electrode member (122) and the third electrode member (123) and, if applicable, the first supplemental electrode member (131), the second supplemental electrode member (132) and the third supplemental electrode member (133) to a pulse generator.24.123P-WO / 18.11.202515. A method of implanting the medical lead of any one of the claims 13 to 14, comprising the steps:- Introducing the distal end of the medical lead into the patient’ s body at a pre-defined position between the sternum and the heart,- Moving the spreading member, for example by means of a wire-like element connected to the spreading member, such that the initially connected and / or close- fitted at least two leaf-shaped elements of the first leaf-shaped element (111, 211) and the second leaf-shaped element (112, 212) and the at least one third leaf-shaped element (113, 213) are disconnected and spread at a desired time point.24.123P-WO / 18.11.2025

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