Medical lead system with fixation member covering and associated methods

Abstract

Medical lead systems facilitating protection of a fixation member and methods of use thereof are disclosed herein. In some variations, a medical lead system with fixation member protection can include a lead body having a distal end portion, a fixation member coupled to a distal end portion of the lead body, and a balloon arrangement including a proximal balloon lobe and a distal balloon lobe. Each balloon lobe can have a contracted configuration and an expanded configuration. When the proximal and distal balloon lobes are in their expanded configurations, the proximal balloon lobe may be configured to urge the distal balloon lobe in a distal direction to at least partially cover the fixation member (e.g., during delivery of the medical lead system in a patient).

Description

MEDICAL LEAD SYSTEM WITH FIXATION MEMBER COVERING AND ASSOCIATED METHODSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of priority to U.S. Provisional Application No. 63 / 620,310, filed January 12, 2024, which is incorporated by reference herein in its entirety.TECHNICAL FIELD

[0002] The present technology relates to a medical system and method and, more particularly, a medical lead system and method facilitating covering of a fixation member.BACKGROUND

[0003] A variety of cardiac dysfunctions can be treated with an implantable medical lead. For example, the medical lead may include one or more electrodes that establish electrical communication with cardiac tissue for sensing cardiac signals generated by a patient’s heart and / or deliver cardiac pacing to the patient. The medical lead can be steered and navigated through vasculature to reach a suitable target location within the heart for performing such sensing and / or therapy delivery functions.

[0004] In some instances, the medical lead may include a fixation element to help anchor the medical lead in tissue once the medical lead is placed. However, there is a risk that the fixation element prematurely engages vascular tissue and / or other architecture in the patient’s body, causing undesirable tissue damage, device damage, and / or inaccurate fixation of the medical lead with respect to the target location. Accordingly, there is a need for a new and improved medical lead system.SUMMARY

[0005] The subject technology is illustrated, for example, according to various aspects described below, including with reference to FIGS. 1-9. Various examples of aspects of the subject technology are described as numbered examples (1, 2, 3, etc.) for convenience. These are provided as examples and do not limit the subject technology.Example 1. A medical lead system, comprising:a lead body having a distal end portion; a fixation member coupled to a distal end portion of the lead body; a balloon arrangement coupled to the lead body and comprising a proximal balloon lobe and a distal balloon lobe, each balloon lobe having a contracted configuration and an expanded configuration, wherein when the proximal and distal balloon lobes are in their expanded configurations, the proximal balloon lobe is configured to urge the distal balloon lobe in a distal direction to at least partially cover the fixation member.Example 2. The medical lead system of example 1, wherein when the distal balloon lobe is in the expanded configuration, the distal balloon lobe is configured to extend distally beyond the fixation member.Example 3. The medical lead system of example 1 or 2, wherein when the distal balloon lobe is in the expanded configuration, the distal balloon lobe is configured to substantially circumferentially surround the fixation member.Example 4. The medical lead system of any one of examples 1-3, wherein the balloon arrangement comprises a single balloon comprising the proximal balloon lobe and the distal balloon lobe.Example 5. The medical lead system of any one of examples 1-3, wherein the balloon arrangement comprises a distal balloon comprising the distal balloon lobe and a proximal balloon comprising the proximal balloon lobe.Example 6. The medical lead system of any one of examples 1-5, further comprising a cinch configured to circumferentially restrain the balloon arrangement between the proximal balloon lobe and distal balloon lobe.Example 7. The medical lead system of example 6, wherein the cinch comprises a material with lower elasticity compared to the proximal balloon lobe and the distal balloon lobe.Example 8. The medical lead system of example 6 or 7, wherein the cinch comprises a metal ring.Example 9. The medical lead system of any one of examples 6-8, wherein the cinch comprises a region of balloon material having lower elasticity compared to the proximal balloon lobe and the distal balloon lobe.Example 10. The medical lead system of any one of examples 1-9, wherein the lead body comprises a balloon shaft portion comprising at least one inflation port in fluidic communication with at least one of the proximal balloon lobe or distal balloon lobe.Example 11. The medical lead system of example 10, wherein the balloon shaft portion comprises a plurality of inflation ports, each inflation port in fluidic communication with at least one of the proximal balloon lobe or distal balloon lobe.Example 12. The medical lead system of example 11, wherein the plurality of inflation ports comprises a first inflation port in fluidic communication with the proximal balloon lobe, and a second inflation port in fluidic communication with the distal balloon lobe.Example 13. The medical lead system of any one of examples 10-12, wherein the lead body comprises at least one inflation lumen in fluidic communication with one or more inflation ports.Example 14. The medical lead system of any one of examples 1-13, wherein the fixation member comprises a helical anchor.Example 15. The medical lead system of any one of examples 1-14, wherein the fixation member comprises an electrode.Example 16. The medical lead system of example 15, wherein the electrode is configurable as a sensing electrode, a stimulation electrode, or both.Example 17. The medical lead system of example 15 or 16, wherein the lead body is a cardiac pacing lead and the medical lead system further comprises a proximal connector configured to mechanically and electrically couple the cardiac pacing lead to an electrical stimulation device.Example 18. A system comprising: the medical lead system of any one of examples 1-17; and a medical device coupled to the lead body, wherein the medical device comprises circuitry configured to electrically communicate with the lead body.Example 19. The system of example 18, wherein the lead body comprises an electrode configurable as a sensing electrode.Example 20. The system of example 19, wherein the circuitry is configured to sense cardiac signals from the electrode.Example 21. The system of any one of examples 18-20, wherein the lead body comprises an electrode configurable as a stimulation electrode.Example 22. The system of example 21, wherein the circuitry is configured to generate cardiac pacing signals.Example 23. A method, comprising: advancing a lead body toward a target region of a patient, wherein a fixation member and a balloon arrangement are coupled to a distal end portion of the lead body, the balloon arrangement comprising a proximal balloon lobe and a distal balloon lobe; and expanding the proximal and distal balloon lobes such that the proximal balloon lobe urges the distal balloon lobe in a distal direction, thereby at least partially covering the fixation member.Example 24. The method of example 23, wherein expanding the proximal and distal balloon lobes causes the distal balloon lobe to extend distally beyond the fixation member.Example 25. The method of example 23 or 24, wherein expanding the proximal and distal balloon lobes causes the distal balloon lobe to substantially circumferentially surround the fixation member.Example 26. The method of any one of examples 23-25, wherein expanding the proximal and distal balloon lobes comprises expanding the proximal balloon lobe and the distal balloon lobes simultaneously.Example 27. The method of any one of examples 23-26, wherein expanding the proximal and distal balloon lobes comprises expanding the proximal balloon lobe followed by expanding the distal balloon lobe.Example 28. The method of any one of examples 23-27, wherein expanding the proximal and distal balloon lobes comprises expanding the distal balloon lobe followed by expanding the proximal balloon lobe.Example 29. The method of any one of examples 23-28, further comprising contracting the proximal balloon lobe, the distal balloon lobe, or both the proximal and distal balloon lobes to thereby at least partially expose the fixation member.Example 30. The method of example 29, wherein contracting comprises contracting the proximal and distal lobes simultaneously.Example 31. The method of example 29 or 30, comprising contracting the proximal balloon lobe followed by contracting the distal balloon lobe.Example 32. The method of any one of examples 29-31, comprising contracting the distal balloon lobe followed by contracting the proximal balloon lobe.Example 33. The method of any one of examples 29-32, further comprising anchoring the fixation member in tissue at the target region of the patient.Example 34. The method of any one of examples 23-33, wherein the target region is in a heart of the patient.Example 35. The method of any one of examples 23-34, wherein the target region is in a chamber of the heart.Example 36. The method of any one of examples 23-35, wherein the target region is in a left ventricle of the heart.Example 37. The method of any one of examples 33-36, wherein anchoring comprises anchoring the fixation member in an interventricular septum of the patient.Example 38. The method of any one of examples 23-37, wherein the fixation member comprises an electrode, the method further comprising delivering pacing therapy signals via the electrode.Example 39. A medical lead system, comprising: a lead body having a distal end portion; a fixation member coupled to a distal end portion of the lead body; a balloon arrangement coupled to the lead body and comprising one or more balloon lobes having a contracted configuration and an expanded configuration; and a stop coupled to the lead body and comprising an inner stop surface and an outer stop surface, wherein the outer stop surface extends distally beyond the inner stop surface so as to form an overhang that is positioned around a proximal portion of the balloon arrangement; wherein when the one or more balloon lobes are in their expanded configurations, the stop is configured to urge the balloon arrangement in a distal direction to at least partially cover the fixation member.Example 40. The medical lead system of example 39, wherein the stop comprises a material with lower elasticity compared to the one or more balloon lobes.Example 41. The medical lead system of example 39 or 40, wherein the stop comprises a first ring having a first axial length measured along a longitudinal axis of the leadbody, and a second ring having a second axial length measured along the longitudinal axis of the lead body, wherein the second axial length is longer than the first axial length.Example 42. The medical lead system of example 41, wherein the first ring and the second ring are separate structures.Example 43. The medical lead system of example 41, wherein the first ring and the second ring are coupled to one another or integrally formed.Example 44. The medical lead system of any one of examples 40-43, wherein the material comprises a metal.Example 45. The medical lead system of any one of examples 39-44, wherein the stop comprises a radiopaque material.Example 46. The medical lead system of any one of examples 39-45, wherein the balloon arrangement comprises two or more balloon lobes.Example 47. The medical lead system of example 46, wherein the two or more balloon lobes comprise a proximal balloon lobe and a distal balloon lobe.Example 48. A system comprising: the medical lead system of any one of examples 39-47; and a medical device coupled to the lead body, wherein the medical device comprises circuitry configured to electrically communicate with the lead body.Example 49. The system of example 48, wherein the lead body comprises an electrode configurable as a sensing electrode.Example 50. The system of example 49, wherein the circuitry is configured to sense cardiac signals from the electrode.Example 51. The system of any one of examples 48-50, wherein the lead body comprises an electrode configurable as a stimulation electrode.Example 52. The system of example 51, wherein the circuitry is configured to generate cardiac pacing signals.Example 53. A method, comprising: advancing a lead body toward a target region of a patient, wherein a fixation member and a balloon arrangement are coupled to a distal end portion of the lead body, the balloon arrangement comprising one or more balloon lobes, and wherein a stop is coupled to the lead body and comprises an inner stop surface and an outer stop surface extending distally beyond the inner stop surface and around a proximal portion of the balloon arrangement; and expanding the one or more balloon lobes such that the stop urges the proximal portion of the balloon arrangement in a distal direction, thereby at least partially covering the fixation member.Example 54. The method of example 53, wherein expanding the one or more balloon lobes causes at least one balloon lobe to extend distally beyond the fixation member.Example 55. The method of example 53 or 54, wherein expanding the one or more balloon lobes causes at least one balloon lobe to substantially circumferentially surround the fixation member.Example 56. The method of any one of examples 53-55, further comprising contracting the one or more balloon lobes.Example 57. The method of any one of examples 53-56, further comprising anchoring the fixation member in tissue at the target region of the patient.Example 58. The method of any one of examples 53-57, wherein the target region is in a heart of the patient.Example 59. The method of any one of examples 53-58, wherein the target region is in a chamber of the heart.Example 60. The method of any one of examples 53-59, wherein the target region is in a left ventricle of the heart.Example 61. The method of any one of examples 57-60, wherein anchoring comprises anchoring the fixation member in an interventricular septum of the patient.Example 62. The method of any one of examples 53-62, wherein the fixation member comprises an electrode, the method further comprising delivering pacing therapy signals via the electrode.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on illustrating clearly the principles of the present disclosure.

[0007] FIG. 1 is an illustrative schematic of an example medical lead system accessing a target region within a patient, in accordance with the present technology.

[0008] FIGS. 2 A and 2B are illustrative schematics of a portion of an example medical lead system in accordance with the present technology, including a balloon arrangement with balloon lobes in a contracted configuration and an expanded configuration, respectively.

[0009] FIGS. 3A-3D are illustrative schematics of example balloon arrangements in a medical lead system in accordance with the present technology.

[0010] FIG. 4 is an illustrative schematic of a portion of a lead body in an example medical lead system in accordance with the present technology.

[0011] FIGS. 5A-5E are illustrative schematics of example inflation port arrangements in a lead body in a medical lead system in accordance with the present technology.

[0012] FIG. 6 is an illustrative flowchart of an example method of placing and operating a medical lead system in a patient, in accordance with the present technology.

[0013] FIGS. 7A-7E are illustrative schematics of portions of an example method of placing a medical lead system in a patent, in accordance with the present technology.

[0014] FIGS. 8 A and 8B are illustrative schematics of an example medical lead system in accordance with the present technology, including a balloon arrangement with a balloon lobe in a contracted configuration and an expanded configuration, respectively. FIG. 8C is an illustrative schematic of an example alternative medical lead system.

[0015] FIG. 9 is an illustrative flowchart of an example method of placing and operating a medical lead system in a patient, in accordance with the present technology.DETAILED DESCRIPTION

[0016] The present technology relates to a medical lead system and associated methods. Some variations of the present technology, for example, are directed to a medical lead system including a medical lead and a medical device, with one or more features facilitating protection of a fixation member on the medical lead. Specific details of several variations of the technology are described below with reference to FIGS. 1-9.I. Medical lead systems

[0017] Generally, in some variations, a medical lead system may include a lead body, a fixation member on the lead body, and a balloon arrangement including a proximal balloon lobe and a distal balloon lobe on the lead body proximate to the fixation member. Each balloon lobe may have a contracted (e.g., deflated) configuration and an expanded (e.g., inflated) configuration. In some variations, when the balloon lobes are expanded (e.g., inflated), the proximal balloon lobe urges the distal balloon lobe in a distal direction (and / or prevent the expansion of the distal balloon lobe in a proximal direction) to at least partially cover the fixation member. For example, when the balloon lobes are expanded, the distal balloon lobe may be configured to extend distally beyond the fixation member and / or at least partially circumferentially surround the fixation member. In some variations, the balloon lobes may be expanded during positioning of the lead body in a patient, such that the balloon arrangement substantially prevents the fixation helix from prematurely engaging tissue in an undesired location (e.g., to avoid anchoring the lead body in an undesired tissue location, to avoid tissue damage, etc.). Once the fixation member is positioned appropriately and ready to be fixated in tissue in a target region, the proximal and / or distal balloon lobes may be returned to their contracted configuration, thereby exposing the fixation member for tissue engagement.

[0018] Accordingly, in some variations, the proximal balloon lobe may be configured to provide a “backstop” support for extending the distal balloon lobe distally beyond thefixation member and / or circumferentially surrounding the fixation member. Advantageously, the arrangement of multiple balloon lobes can be easily configured to provide for better control of how the expanded distal balloon lobe is positioned for covering the fixation member. For example, the proximal balloon lobe can be designed and / or controlled to shape the expanded distal balloon lobe to a further distal extension, without simultaneously requiring greater radial expansion. In some variations, the lesser degree of distal balloon lobe expansion necessary to sufficiently extend distally beyond the fixation member may additionally facilitate increased elastic recovery of the balloon lobes. For example, by avoiding straining the material of the distal balloon lobe beyond its elastic region during expansion, the distal balloon lobe may return to its contracted configuration without being “stretched” or “baggy” as the result of plastic deformation. This elastic recovery can help prevent the distal balloon lobe from inadvertently catching on the fixation member when transitioning to the contracted configuration. Additionally or alternatively, the interaction between the proximal balloon lobe and the distal balloon lobe may furthermore help reduce the amount of balloon material required to achieve a certain amount of distal protection of the fixation member, thereby advantageously reducing the delivery profile of the lead body for placement in a patient.[00191 In some variations, the medical lead system may be configured to electrically communicate with tissue in a patient. For example, the lead body may include one or more electrodes configured to detect electrical signals in tissue and / or delivery therapy (e.g., pacing) to a heart. For example, FIG. 1 is an illustrative schematic of an example medical lead system 100 including a lead body 110 extending from a medical device 102 (e.g., electrical stimulation device) through vasculature of a patient. The lead body 110 may, for example, include an elongated member that is sufficiently flexible so as to be navigable within vasculature and / or other lumen within a patient (e.g., using suitable guidewire techniques, etc.). The lead body 110 may include a distal end portion 1 lOd that is positionable at a target region T within the patient. In some variations, the medical lead system 100 may include one or more proximal connectors (e.g. mating components) that function to mechanically and / or electrically couple the lead body 110 to the medical device 102. For example, a proximal end portion of lead body 110 may include at least one proximal connector configured to mate or otherwise engage with the medical device 102. Additionally or alternatively, in some variations a proximal end portion of the lead body 110 may be secured within a corresponding receptacle in the medical device 102 with one or more fasteners (e.g., set screws).

[0020] In some variations, as shown in FIGS. 2A and 2B for example, the medical lead system 100 may further include a sheath 150 (e.g., an introducer sheath and / or delivery catheter) configured to deliver the lead body 110 towards a target region of the patient. As shown in FIG. 2A, the sheath 150 may include a sheath lumen 152 configured to receive the lead body 110 and allow the lead body 110 to exit through a distal sheath opening 154. For example, the sheath 150 may be retracted proximally and / or the lead body 110 may be advanced distally to expose at least a distal end portion of the lead body 110 relative to the sheath 150.

[0021] At least one fixation member 112 on the distal end portion HOd may be configured to penetrate tissue of the patient at a target region T (e.g., cardiac tissue in a right ventricle (RV), right atrium (RA), left ventricle (LV), and / or left atrium (LA). For example, as shown in FIG. 1, the target region T may be in an interventricular septum of a heart H of the patient. However, the target region T may be in any suitable region of cardiac tissue or other tissue of the patient.

[0022] In some variations, as shown in FIGS. 2 A and 2B for example, the fixation member 112 may include a helical structure configured to fixate within tissue when rotated. However, the fixation member 112 may have any other shape suitable for engaging tissue (e.g., tine, screw, ring, hook, etc.). In some variations, the fixation member 112 may be configured to remain substantially stationary with respect to the distal end HOd of the lead body 110. Alternatively, the fixation member 112 may be configured to translate relative to the distal end HOd of the lead body 110. For example, the fixation member 112 may be configured to translate distally and / or proximally within a lumen of the lead body 110.

[0023] In some variations, the fixation member 112 may include an electrode configured to electrically communicate with the tissue that the fixation member 112 penetrates. For example, as shown in FIGS. 2A and 2B, the fixation member 112 may include an electrode 114. The electrode 114 may be electrically connected to one or more conductors (not shown in FIG. 1) extending through the lead body 110. The conductors may, for example, be electrically connected to circuitry 104 of the medical device 102, with circuitry 104 configured to generate therapy signals and / or sense cardiac signals from the electrode communicated via the conductors. The fixation member 112 may be configured to position the electrode 114 such that the electrode conducts the electrical signals to the heart H, causing the cardiac muscle (e.g., of the ventricles) to depolarize and, in turn, contract at a regular interval, such as for pacing purposes.

[0024] As described in further detail herein, the medical lead system 100 may further include a balloon arrangement configured to help reduce the risk of the fixation member 112 of penetrating or otherwise engaging tissue in undesired tissue (e.g., tissue other than the target region T). As shown in FIG. 2A, for example, the medical lead system 100 may include a balloon arrangement 130 including a proximal balloon lobe 132 and a distal balloon lobe 134 arranged on the lead body 110, such as on a balloon shaft portion 120 of the lead body 110 adjacent to the fixation member 112. Each of the proximal balloon lobe 132 and the distal balloon lobe 134 may have a contracted (e.g., deflated) configuration as shown in FIG. 2A, and an expanded (e.g., inflated) configuration as shown in FIG. 2B. The balloon lobes may be formed of a suitable elastic material, such as silicone.

[0025] As shown in FIGS. 2A and 2B, the balloon lobes may have outer walls that are generally radially closer to balloon shaft portion 120 when in the contracted configuration, and generally radially farther from the balloon shaft portion 120 when in the expanded configuration. In other words, when the proximal balloon lobe 132 is in its contracted configuration (FIG. 2A), it may have a smaller outer diameter compared to when the proximal balloon lobe 132 is in its expanded configuration (FIG. 2B). For example, the proximal balloon lobe 132 may have a first average diameter in the contracted configuration and a second average diameter in the expanded configuration, where an expansion ratio of the second average diameter to the first average diameter may be between about 1.5 and about 5, or between about 2 and about 4, or more than about 5. For example, the ratio of the second average diameter to the first average diameter may be about 1.5: 1, about 2: 1, about 3: 1, about 3: 1, about 3.5: 1, about 4: 1, about 4.5: 1, about 5: 1, or about 6: 1 or greater. Similarly, when the distal balloon lobe 134 is in its contracted configuration (FIG. 2A), it may have a smaller outer diameter compared to when the distal balloon lobe 134 is in its expanded configuration (FIG. 2B). For example, the distal balloon lobe 134 may have a first average diameter in the contracted configuration and a second average diameter in the expanded configuration, where an expansion ratio of the second average diameter to the first average diameter may be between about 1.5 and about 5, or between about 2 and about 4, or more than about 5. For example, the ratio of the second diameter to the first diameter may be about 1.5: 1, about 2: 1, about 3: 1, about 3: 1, about 3.5: l, about 4: l, about 4.5: 1, about 5: l, or about 6: 1 or greater. The expansion ratios for the proximal balloon lobe 132 and the distal balloon lobe 134 may be equal or unequal. In some example variations, one or both of the balloon lobes 132, 134 has an expanded average diameter of between about 8 mm and about 13 mm.

[0026] The balloon lobes may be in the contracted configuration when the portion of the lead body 110 carrying the balloon arrangement 130 is received within the sheath 150. As shown in FIG. 2 A, the balloon arrangement 130 may exit the sheath opening 154 to be exposed relative to the sheath 150. For example, the sheath 150 may be retracted proximally and / or the lead body 110 may be advanced distally to expose the balloon arrangement 130 and the fixation member 112. When free of the constraint of the sheath 150, the proximal and distal balloon lobes may be inflated (e.g., via introduction of an inflation fluid as further described below) to their expanded configurations. A distal surface of the expanded proximal balloon lobe 132 may abut (touch) a proximal surface of the expanded distal balloon lobe 134 at a balloon lobe interface 133, such that the proximal balloon lobe 132 pushes distally against the distal balloon lobe 134, thereby urging the distal balloon lobe 134 into a position that at least partially covers the fixation member 112.

[0027] Furthermore, in some variations, when the proximal balloon lobe 134 is inflated, the sheath 150 may be positioned relative to the proximal balloon lobe 134 such that the sheath 150 (e.g., a distal face of the sheath 150 at the distal sheath opening 154) abuts the proximal surface of the proximal balloon lobe 132. This interaction between the sheath 150 and the proximal balloon lobe 132 may provide a “backstop” support surface against which the proximal balloon lobe 132 can push when expanding or while expanding, such that the proximal balloon lobe 132 resists expansion in a proximal direction and thus is biased towards expanding in a distal direction against the distal balloon lobe 134. Additionally or alternatively, the lead body 110 may include a radial feature (e.g., flange or ring) that has a larger diameter than the diameter of the lead body 110 that functions as a similar backstop support for the proximal balloon lobe 132.

[0028] For example, as shown in FIG. 2B, in some variations, when in the expanded configuration, the distal balloon lobe 134 may define a cavity 136 that receives and at least partially surrounds the fixation member 112. The cavity 136 can, for example, be formed by a region of the distal balloon lobe 134 extending distally beyond a distal bond 144 of the distal balloon lobe 134 to the balloon shaft 120. The cavity 136 may have an open distal end where the balloon wall of the expanded distal balloon lobe 134 begins to curve back proximally. The cavity 136 can be centrally located within the distal balloon lobe 134 (e.g., aligned with a longitudinal axis of the balloon shaft portion 120), or may be radially offset from the balloon shaft portion 120. In some variations, the cavity may have varying diameter, such as a wider or flared diameter toward its distal end compared to its proximal end. In some variations, forexample, the cavity may have a length of between about 1 mm and about 1mm, and / or a diameter (e.g., at the distal end of the cavity) of between about 2 mm and about 4mm. In some variations, a band (e.g., radiopaque marker band) may be arranged over the distal bond 144 to help secure the distal end of the distal balloon lobe 134 to the balloon shaft and / or provide a radiopaque reference marker visible under imaging such as fluoroscopy.

[0029] In some variations, the proximal balloon lobe 132 and / or the distal balloon lobe 134 may have a generally toroidal shape that is arranged around the balloon shaft portion 120. However, in some variations the proximal balloon lobe and / or distal balloon lobe may have other suitable shapes or profiles (e.g., flared, trumpeted, tapered, etc.). Furthermore, as further described below, the overall dimensions (length, first average diameter, second average diameter, etc.) and / or profile (e.g., constant diameter, tapered, etc.) of the proximal balloon lobe 132 and the distal balloon lobe 134 may be the same or different.

[0030] Furthermore, in some variations, the proximal balloon lobe and / or the distal balloon lobe may include multiple sub-lobes arranged circumferentially around the balloon shaft portion 120. For example, the proximal balloon lobe 132 may include multiple sub-lobes (e.g., “petal”-shaped sub-lobes) arranged to distally urge the distal balloon lobe at multiple different respective circumferentially distributed regions. As another example, the proximal balloon lobe 132 may be configured to distally urge multiple sub-lobes of the distal balloon lobe at multiple different respective circumferentially distributed regions. As another example, the proximal balloon lobe 132 may include multiple sub-lobes to distally urge multiple sublobes of the distal balloon lobe at multiple different respective circumferentially distributed regions. A balloon lobe can have any suitable number of sub-lobes (e.g., two, three, four, or more) and be equally or unequally arranged around the balloon shaft portion 120.

[0031] The balloon arrangement 130 is primarily described herein as including a proximal balloon lobe that pushes distally against the distal balloon lobe to urge the distal balloon lobe in a distal direction. However, it should be understood that additionally or alternatively, in some variations, the distal balloon lobe may be configured to urge the proximal balloon lobe in a proximal direction. For example, the distal balloon lobe may be configured to urge the proximal balloon in a proximal direction to at least partially cover a fixation member (e.g., tine), an electrode, a fragile component, and / or other feature located proximal to the balloon arrangement 130.

[0032] The proximal and distal balloon lobes may be formed from one or multiple discrete balloons. In some variations, the balloon arrangement may include a single balloon that is manipulated to form multiple balloon lobes. For example, as shown in FIGS. 2A, 2B, and 3, the balloon arrangement 130 may include a singular, tubular balloon (of constant or varying diameter) of balloon material. As best shown in FIG. 2B, such a tube may be coupled to the balloon shaft portion 120 at proximal and distal ends of the tube. For example, a proximal end of the tube may be coupled to the balloon shaft portion 120 at a proximal bond 142 forming a first peripheral seal around the balloon shaft portion, and a second end of the tube may be coupled to the balloon shaft portion 120 at a distal bond 144 forming a second peripheral seal around the balloon shaft portion. The proximal bond 142 and the distal bond 144 may, for example, couple the balloon to the balloon shaft portion 120 with epoxy, thermal joining, and / or other suitable bonding technique. A tubular internal balloon volume may be formed between the balloon shaft portion 120, an outer wall of the balloon, the proximal bond 142, and the distal bond 144. In some variations, a band (e.g., radiopaque marker band) may be arranged over the proximal bond 142 to help secure the proximal end of the proximal balloon lobe to the balloon shaft and / or provide a radiopaque reference marker visible under imaging such as fluoroscopy.

[0033] The balloon arrangement may further include a cinch 140 arranged over the balloon between the proximal and distal bonds. The cinch may be configured to restrain the expansion diameter of the balloon at a selected longitudinal location along the balloon, such that when the balloon is inflated, the cinch defines on either side thereof the proximal balloon lobe 142 and the distal balloon lobe 144 that are allowed to expand beyond the diameter of the cinch 140, while allowing the proximal and distal balloon lobes to touch and physically interact with one another. Accordingly, the cinch 140 may function to help define the lobe shapes of a single balloon forming the balloon arrangement 130. In some variations, the cinch further functions to provide support from a proximal side of the distal balloon lobe 144, to help urge the distal balloon lobe 144 in a distal direction (and / or prevent the expansion of the distal balloon lobe 144 in a proximal direction).

[0034] In some variations, the cinch 140 may be shaped to at least partially circumferentially surround the balloon, and may be sized down (e.g., crimped, clamped, heat shrunk, tied, etc.) to provide a restraint force against the balloon when the balloon is expanding. Furthermore, the cinch 140 may include a material that has lower elasticity than the balloon, such that the cinch 140 stretches less than the balloon during balloon expansion and helpsprovide a restraint force against the balloon when the balloon is expanding. For example, the cinch 140 may include a metal or polymer with a higher elastic modulus than the balloon material. In some variations, the cinch 140 may be radiopaque.

[0035] In some variations, the cinch 140 may include an enclosed ring or band that is placed and sized down over the balloon. As another example, the cinch 140 may include a coil, or a partial ring or band (e.g., “C”-shaped ring or band) that is placed and sized down over the balloon. As another example, the cinch 140 may include a filament (e.g., polyester fiber or other filament) that is tied, sewn, woven, or otherwise arranged over the balloon. Additionally or alternatively, in some variations the cinch 140 may include a portion of the balloon material itself, such as a region with a thicker or reinforced balloon wall that resists expansion more compared to the regions of the balloon wall that correspond to the main proximal and distal balloon lobes. The balloon arrangement 130 may include multiple cinches 140 operating in combination at the same general longitudinal location on the balloon.

[0036] In some variations, the balloon arrangement may include multiple discrete balloons. For example, as shown in the schematic of FIG. 3B, in some variations the balloon arrangement 130 may include a first balloon forming the proximal balloon lobe 132 and a second balloon forming the distal balloon lobe 134. A cinch 140 (outlined in dashed line for visual clarity of the balloons), such as similar to that described above with respect to FIG. 3, may also be arranged over and / or between the balloons forming the proximal balloon lobe 132 and the distal balloon lobe 134. In variations in which the balloon arrangement includes multiple discrete balloons, each balloon may have proximal and distal bonds (similar to bonds 142 and 144 described above) on its respective proximal and distal ends that couple the balloon to the balloon shaft portion 120. Additionally or alternatively, a cinch 140 may be arranged and sized down over the distal end of the proximal balloon lobe 132 and / or the proximal end of the distal balloon lobe 134, so as to assist in sealing the distal end of the proximal balloon lobe 132 and / or the proximal end of the distal balloon lobe 134 to the balloon shaft portion 120 of the lead body.

[0037] While in some variations the proximal balloon lobe may be approximately the same size and / or shape as the distal balloon lobe (e.g., in length, contracted diameter, contracted profile, expanded diameter, expanded profile, etc.), in some variations the proximal balloon lobe may be different in size and / or shape than the distal balloon lobe. For example, while the proximal balloon lobe 132 and the distal balloon lobe 134 may have approximately the same length measured along a longitudinal axis of the lead body (as shown in FIGS. 3Aand 3B, for example), in some variations the proximal balloon lobe 132 may be shorter than the distal balloon lobe 134 (FIG. 3C), or the proximal balloon lobe 132 may be longer than the distal balloon lobe 134 (FIG. 3D). Additionally or alternatively, as another example, the proximal balloon lobe 132 may have a larger expanded diameter in its expanded configuration than the distal balloon lobe 134 in its expanded configuration, which may, for example, help generate more distally directed force against the distal balloon lobe 134. However, in some variations the proximal balloon lobe 132 may have a smaller expanded diameter in its expanded configuration than the distal balloon lobe 134 in its expanded configuration.[0038| In some variations, the proximal balloon lobe 132 and the distal balloon lobe 134 may include the same balloon material and wall thickness. However, in some variations the balloon material and / or wall thickness may vary between the proximal balloon lobe 132 and the distal balloon lobe 134 so as to enable one of the balloon lobes to be more flexible or elastic (and thus easier to manipulate) than the other. For example, in some variations the proximal balloon lobe 132 may overall be more rigid than the distal balloon lobe 134, such as by including a balloon material with a higher elastic modulus and / or having a thicker balloon wall compared to the distal balloon lobe 134. Alternatively, in some variations the proximal balloon lobe 132 may overall be less rigid than the distal balloon lobe 134, such as by including a balloon material with a lower elastic modulus and / or having a thinner balloon wall compared to the distal balloon lobe 134.

[0039] The balloon shaft portion 120 of the lead body 110 may, in some variations, include one or more inflation ports in fluidic communication with the balloon arrangement 130 to facilitate the contraction and / or expansion of the balloon lobes 132, 134. For example, in some variations, the lead body 110 may include at least one lumen extending along the length of the lead body 110 and opening to one or more inflation ports that are in fluidic communication with the internal volume of at least one balloon lobe. By way of illustration, as shown in FIG. 4, the lead body 110 may include at least one lumen 118 configured to carry an inflation fluid (e.g., saline, a suitable gas, etc.) to and from at least one inflation port 122a that is in fluidic communication with the proximal balloon lobe 132. In some variations, the inflation ports 122a may additionally be in fluidic communication with the distal balloon lobe 134. For example, while FIG. 4 illustrates two inflation ports 122a that are located on opposite sides of the lumen 118 and open directly into the proximal balloon lobe 132, in some variations the proximal balloon lobe 132 may be formed from the same balloon as the distal balloon lobe134, such that the inflation of both the proximal and distal balloon lobes 132, 134 can be accomplished via the inflation ports 122a.[00401 When the inflation fluid is introduced into the balloon lobe(s) via the inflation ports 122a (e.g., from a source pumped from outside the patient), at least one of the balloon lobes may transition from the contracted configuration to the expanded configuration. Conversely, when the inflation fluid is removed from the balloon lobe(s) via the inflation ports 122a (e.g., with a vacuum source from outside the patient), at least one of the balloon lobes may transition from the expanded configuration to the contracted configuration. Accordingly, a pump located external to the patient may be configured to introduce and / or remove inflation fluid to and / or from the balloon arrangement to control the expansion and / or contraction of the balloon lobes of the balloon arrangement.[0041 [ As shown in FIG. 4, in some variations the lumen 114 may also be configured to carry a conductor 116 (e.g., wire) in electrical communication with one or more electrodes on the lead body 110 (e.g., electrode 114, not shown in FIG. 4). However, in some variations the lead body 110 may include multiple lumens for different purposes (e.g., one lumen for carrying inflation fluid, another lumen for carrying a conductor). Furthermore, in some variations the lead body 110 may include multiple lumens, each in communication with a respective inflation port (and / or respective balloon lobe or region of a balloon lobe), as further described below.

[0042] Although FIG. 4 illustrates a set of two inflation ports 122a on opposite sides of the lumen 118, the lead body 110 may include any suitable arrangement of inflation port(s), as shown in FIGS. 5 A-5E. The pattern of inflation port(s) relative to the balloon lobes, and / or the network of inflation lumens that are in fluidic communication with the inflation port(s), may help facilitate selective inflation and / or deflation of the balloon lobes. Multiple inflation ports on the balloon shaft portion 120 of the lead body 110 may be equally or unequally distributed along the length of the balloon arrangement (or along the length of the proximal balloon lobe or distal balloon lobe). Additionally or alternatively, multiple inflation ports may be equally or unequally distributed circumferentially around the balloon shaft portion 120 of the lead body 110.

[0043] In some variations, one or more inflation ports 122 may be arranged under the cinch 140 (e.g., between the proximal balloon lobe 132 and the distal balloon lobe 134). As shown in FIG. 5 A, the inflation ports 122 under the cinch may be in fluidic communicationwith a single balloon that forms the proximal balloon lobe 132 and the distal balloon lobe 134. As such, expansion of the proximal and distal balloons may be accomplished substantially simultaneously by controlling the passage of inflation fluid through the inflation ports 122.

[0044] In some variations, at least one inflation port may be arranged under each balloon lobe. For example, at least one proximal inflation port 122a may be arranged in direct fluidic communication with the proximal balloon lobe 132 and at least one distal inflation port 122b may be arranged in direct fluidic communication with the distal balloon lobe 134, either when the balloon lobes are formed from the same single balloon (FIG. 5B) or when the balloon lobes are formed from discrete balloons (FIG. 5C). The proximal and distal inflation ports 122a, 122b may be in fluidic communication with a common inflation lumen 118 (not shown) that enables substantially simultaneous expansion of the proximal and distal balloon lobes. Alternatively, a first inflation lumen may be in fluidic communication with the proximal inflation port 122a and a second inflation lumen may be in fluidic communication with the distal inflation port 122b, thereby enabling independent expansion of the proximal and distal balloon lobes.

[0045] Additionally or alternatively, in some variations, multiple inflation ports may be arranged under one or more balloon lobes. For example, multiple inflation ports 122a may be arranged under the proximal balloon lobe (FIG. 5D), and / or multiple inflation ports 122b may be arranged under the distal balloon lobe (FIG. 5E). Additionally or alternatively, the inflation ports may be generally the same size and / or shape, or some inflation ports may have different sizes or shapes. For example, as shown in FIG. 5D, proximal inflation ports 122a under the proximal balloon lobe 132 may have a smaller diameter than distal inflation ports 122b under the distal balloon lobe 134, which may help facilitate a faster rate of expansion of the distal balloon lobe 134 than the proximal balloon lobe 132. As another example, as shown in FIG. 5E, proximal inflation ports 122a under the proximal balloon lobe 132 may have a larger diameter than distal inflation ports 122b under the distal balloon lobe 134, which may help facilitate a faster rate of expansion of the proximal balloon lobe 132 than the distal balloon lobe 134. In some variations, for example, an inflation port can have a diameter of between about 0.5 mm and about 1 mm. Furthermore, a set of inflation ports under a particular balloon lobe may or may not be similar in size and / or shape.

[0046] While the inflation ports shown in FIGS. 5A-5E are illustrated as generally circular, it should be understood that other shapes of inflation port openings may be suitable (e.g., slit, partial ring, etc.). Additionally or alternatively, in some variations, one or morevalves may be arranged in an inflation port to help regulate inflow and / or outflow of inflation fluid in and / or out of the balloon arrangement.[00471 In some variations, a medical lead system (e.g., medical lead system 100) may include a stop arranged on the lead body, where the stop is configured to at least partially surround a proximal portion of the balloon arrangement (e.g., a proximal portion of a proximal balloon lobe, or a proximal portion of a single balloon) with an overhang structure configured to urge the balloon arrangement to extend distally beyond and / or circumferentially around a fixation element on a distal portion of the lead body.

[0048] For example, FIGS. 8A and 8B illustrate another example medical lead system 100 including a balloon arrangement 130 and a stop 160 having an overhang structure arranged around a portion of the balloon arrangement. Except as described below, the medical lead system 100 may be similar to other variations of the medical lead system 100 described herein (e.g., having a lead body 110, fixation member 112, one or more inflation ports, etc.). Although the medical lead system 100 shown in FIGS. 8A and 8B is depicted as having a balloon arrangement with a single balloon lobe 131 for ease of explanation, it should be understood that in other variations the medical lead system 100 may include a balloon arrangement with two or more balloon lobes (e.g., a proximal lobe and a distal lobe), with a stop 160 interacting with any one of the multiple balloon lobes (e.g., the proximal lobe).

[0049] As shown in FIG. 8 A, the stop 160 may include an inner ring structure 162 and an outer ring structure 164. The inner ring structure 162 may be coupled to and / or arranged around a proximal end of the balloon lobe 131 (e.g., around a portion of the balloon lobe 131 that is bonded to the lead body 110). The outer ring structure 164 may have an inner diameter that is equal to or larger than the outer diameter of the inner ring structure 162, with the outer ring structure 164 arranged around (e.g., overlaid on) the inner ring structure 162. The outer ring structure 164 may have an axial length (L2) (as measured along a longitudinal axis of the lead body 110) that is longer than the axial length (LI) of the inner ring structure 162, so as to form an overhang structure (e.g., axial projection) that extends distally beyond the inner ring structure 162 and around a proximal portion of the balloon lobe 131. In other words, a proximal portion of the balloon lobe 131 may be positioned within an arcuate (e.g., annular) space formed between the shaft 120 and the outer ring structure 164, where the radial thickness of the arcuate space is defined at least in part by the thickness of the inner ring structure 162. In some variations, the ratio of L2 to LI is between about 1.5: 1 and about 3: 1 (e.g., about 2: 1).

[0050] Generally, due to the position of the portion of the balloon lobe 131 that is covered by the overhang structure of the stop 160, when the balloon lobe 131 is expanded, the balloon lobe 131 is primarily urged to expand in a distal direction to extend distally beyond and / or surround the fixation element 112. For example, as shown in FIG. 8B, the inner ring structure 162 may provide an inner stop surface (e.g., distal face) functioning as a proximal backstop to restrict or prevent expansion, in a proximal direction, of the proximal portion of the balloon lobe 131 that is covered by the overhang. Additionally, the overhang provided by the distally-extending part of the outer ring structure 164 may restrict or prevent radial expansion of the proximal portion of balloon lobe 131 that is covered by the overhang. An outer stop surface (e.g., distal face) of the outer ring structure 164 may function, to some degree, as an additional backstop to help proximally support the expanded balloon lobe 131.

[0051] Accordingly, as a result of the balloon lobe’s physical interference with the stop 160, as the balloon lobe 131 transitions to its expanded configuration, the stop 160 may primarily urge the expansion of the balloon lobe 131 in a distal direction (with radial expansion permitted for portions of the balloon lobe 131 that are not covered by the overhang or other portion of the stop 160), thereby enhancing the covering of the fixation element 112. The effect of the overhang feature of the stop 160 may be further explained with reference to FIG. 8C, which shows an example medical lead system in which a stop 160' includes only a single ring (which may, for example, be similar to the inner ring structure 162 shown and described with reference to FIG. 8 A). As shown in FIG. 8C, the stop 160' lacks an overhang feature, and thus permits the balloon lobe 131 to expand more proximally relative to the stop 160', thereby potentially reducing the extent to which the balloon lobe 131 may extend distally over and / or around the fixation element 112.

[0052] The stop 160 may be formed in various manners. For example, in some variations, as shown in FIG. 8 A, a proximal edge of the outer ring structure 164 may be substantially aligned with a proximal edge of the inner ring structure 162. However, in some variations the proximal edge of the outer ring structure 164 may extend proximally beyond the proximal edge of the inner ring structure 162 so as to form another overhang structure extending proximally relative to the balloon arrangement 130. For example, in some variations the inner ring structure 162 may be longitudinally centered underneath the outer ring structure 164.

[0053] In some variations, the inner ring structure 162 and the outer ring structure 164 may be separate structures. For example, the inner ring structure 162 and the outer ringstructure 164 may be two distinct rings that are formed separately, then mounted individually (e.g., the inner ring structure 162 mounted to the lead body, then the outer ring structure 164 mounted over the inner ring structure 162 and over a proximal portion of the balloon. In some variations in which the inner and outer ring structures are separately formed, the inner and outer ring structures may be subsequently joined to each other (e.g., with epoxy, via physical interference such as a press fit). However, in some variations in which the inner and outer ring structures are separately formed, the inner and outer ring structures may remain somewhat axially movable to each other (e.g., slip fit). Additionally or alternatively, the inner and outer ring structures may include lips, ribs, textural features, and / or other suitable features to increase physical interference between the inner and outer ring structures to limit or prevent relative axial movement between the inner and outer ring structures.[00541 In some variations, the inner ring structure 162 and the outer ring structure 164 may be integrally formed. For example, the inner and outer ring structures may be cut (e.g., with a lathe, via molding, etc.) from a single piece of material to form a stop 160 with a stepped profile including an inner stop surface and an outer stop surface similar to that shown in FIG. 8A.

[0055] Similar to the cinch 140 described herein, the stop 160 may include a material having a lower elasticity compared to the balloon lobe the stop 160 is covering or otherwise engages with. For example, the stop 160 may include a metal material. In some variations, at least a portion of the stop 160 (e.g., the inner ring structure 162 and / or the outer ring structure 164) may include a radiopaque material to help facilitate visualization of the stop 160, such as under fluoroscopy.II. Methods of placing and operating a medical lead

[0056] Example methods of placing and operating a medical lead described below with reference to the flowcharts of FIG. 6 and 9 and the illustrative schematics of FIGS. 7A-7E. The method may be performed in conjunction, for example, with a medical lead system 100 such as that described herein.

[0057] In some variations, as shown in FIG. 6, a method 600 of placing and operating a medical lead may include advancing a lead body toward a target region of a patient (610), exposing a balloon arrangement and fixation member on the lead body (620), and expanding proximal and distal balloon lobes of the balloon arrangement (630) such that the proximal balloon lobe urges the distal balloon lobe in a distal direction to at least partially cover thefixation member. The method 600 may further include advancing the lead body (640) with the at least partially covered fixation member toward the target region, contracting the proximal and distal balloon lobes (650) to at least partially expose the fixation member, anchoring the fixation member in tissue at the target region (660), and operating the lead body at the target region (670).

[0058] Advancing the lead body toward a target region of the patient (610) functions to generally position the lead body to a location for its operation (e.g., sensing, pacing therapy, etc.). FIG. 7A illustrates an example configuration of the lead system in which the lead body 110 is received in a sheath lumen 152 of a sheath 150. A fixation member 112 (which may include an electrode 114) may also be received in the sheath lumen 152. The lead body 110 and the sheath 150 may be advanced together through vasculature of the patient, such as to an area within a chamber of the heart. For example, the medical lead system may be configured to allow a clinician to navigate the lead body through a vein of the heart (e.g., an innominate vein, an interior vena cava (IVC), and / or a superior vena cava (SVC)) to a target region within a right ventricle (RV), right atrium (RA), or another area of the heart. While the lead body 110 is in the sheath lumen 152, the fixation member 112 may be covered by the sheath 150, thereby substantially preventing the fixation member 112 from inadvertently engaging tissue. Furthermore, as shown in FIG. 7A, the proximal balloon lobe 132 and the distal balloon lobe 134 may be in their contracted (e.g., deflated) configurations, and contained by the sheath 150 until the lead body 110 is in the vicinity of the target region.

[0059] Exposing the balloon arrangement and fixation member on the lead body (620) functions to prepare the fixation member 112 for its fixation in tissue at the target region. As shown in FIG. 7B, the lead body 110 is advanced distally (and / or the sheath 150 is retracted proximally) to expose the proximal and distal balloon lobes 132, 134 and the fixation member.

[0060] Expanding the proximal and distal balloon lobes of the balloon arrangement (630) functions to at least partially cover the fixation member 112 (e.g., by extending distally beyond the distal end of the fixation member 112 and / or circumferentially around the fixation member 112) and reduce the risk of the fixation member 112 from prematurely engaging tissue (e.g., tissue not at the target region). For example, as shown in FIG. 7C, the proximal balloon lobe 132 and the distal balloon lobe 134 may be transitioned to their expanded configurations, where the proximal balloon lobe 132 is configured to press against the distal balloon lobe 134 in a distal direction. This distally directed force may cause the distal balloon lobe 134 to movedistally beyond the fixation member 112 and form a cavity 136 within which the fixation member 112 is housed.

[0061] Expanding the proximal and distal balloon lobes may include delivering an inflation fluid (e.g., saline, air, or other liquid or gas) through one or more inflation ports (not shown) that open into an internal volume of one or both balloon lobes.

[0062] In some variations, the proximal and distal balloon lobes may be expanded substantially simultaneously. Such simultaneous expansion may occur at the same or different rates. Despite being expanded simultaneously, the proximal balloon lobe may be completely expanded before the distal balloon lobe is completely expanded, or the distal balloon lobe may be completely expanded before the proximal balloon lobe is completely expanded (depending on the relative sizes, shapes, and / or inflation speeds of the balloon lobes, for example). Expansion of the proximal and distal balloon lobes may commence at approximately the same time but finish at different times, or may commence at different times but finish at approximately the same time, or may commence and finish at different times but simultaneously occur over some overlapping period of time.

[0063] However, in some variations, the expansion of the proximal and distal balloon lobes may be independently commenced and completed during non-overlapping expansion time periods. For example, in some variations, the distal balloon lobe may begin and finish its transition to the expanded configuration before the proximal balloon lobe begins its transition to the expanded configuration. As another example, the proximal balloon lobe may begin and finish its transition to the expanded configuration before the distal balloon lobe begins its transition to the expanded configuration. As another example, the proximal and distal balloon lobes may be incrementally expanded during a series of alternating, non-overlapping time periods.

[0064] Across these different variations of timing for expansion of the proximal and distal balloon lobes, the fixation member 112 may be at least partially covered by the balloon arrangement once the balloon lobes are expanded.

[0065] With the fixation member 112 at least partially covered as described herein, the lead body 110 (with the balloon arrangement and the fixation member coupled thereto) may be further advanced toward the target region T (640), as shown in FIG. 7D. Once positioned proximate to the target region T, the proximal balloon lobe and / or distal balloon lobe may be contracted (e.g., deflated) to at least partially expose the fixation member (FIG. 7E).

[0066] Contracting the proximal and distal balloon lobes may include removing (e.g., with a vacuum source) the inflation fluid through one or more inflation ports (not shown), thereby removing the inflation fluid from the internal volume of one or both balloon lobes.

[0067] In some variations, the proximal and distal balloon lobes may be contracted substantially simultaneously. Such simultaneous contraction may occur at the same or different rates. Despite being contracted simultaneously, the proximal balloon lobe may be completely contracted before the distal balloon lobe is completely contracted, or the distal balloon lobe may be completely contracted before the proximal balloon lobe is completely expanded (depending on the relative sizes, shapes, and / or inflation speeds of the balloon lobes, for example). Contraction of the proximal and distal balloon lobes may commence at approximately the same time but finish at different times, or may commence at different times but finish at approximately the same time, or may commence and finish at different times but simultaneously occur over some overlapping period of time.

[0068] However, in some variations, the contraction of the proximal and distal balloon lobes may be independently commenced and completed during non-overlapping expansion time periods. For example, in some variations, the distal balloon lobe may begin and finish its transition to the contracted configuration before the proximal balloon lobe begins its transition to the contracted configuration. As another example, the proximal balloon lobe may begin and finish its transition to the contracted configuration before the distal balloon lobe begins its transition to the contracted configuration. As another example, the proximal and distal balloon lobes may be incrementally contracted during a series of alternating, non-overlapping time periods.

[0069] Across these different variations of timing for contraction of the proximal and distal balloon lobes, the fixation member 112 may be at least partially exposed once the balloon lobes are contracted.

[0070] Once at least partially exposed, the fixation member 112 may be anchored or otherwise fixated in tissue of the target region T. For example, in some variations the fixation member 112 may include a helical structure, and the fixation member 112 may be rotated to fixate in tissue. With the fixation member 112 anchored in tissue, the lead body 110 may be considered properly maintained in position at the target region T and operated for its intended purposes. For example, in some variations the lead body 110 may be configured (e.g., withsuitable signals from circuitry 104 in the medical device 102) to deliver pacing signals to cardiac tissue of the patient.[00711 In some variations, as shown in FIG. 9, a method 900 of placing and operating a medical lead may include advancing a lead body toward a target region of a patient (910), exposing a balloon arrangement, a stop, and a fixation member on the lead body (920), and expanding one or more balloon lobes of the balloon arrangement (930) such that the proximal balloon lobe urges the distal balloon lobe in a distal direction to at least partially cover the fixation member. The method 900 may further include advancing the lead body (940) with the at least partially covered fixation member toward the target region, contracting the proximal and distal balloon lobes (950) to at least partially expose the fixation member, anchoring the fixation member in tissue at the target region (960), and operating the lead body at the target region (970). The method 900 may, for example, be performed with a medical lead system 100 such as that described herein with respect to FIGS. 8A and 8B, having a stop including an overhang that is positioned around a proximal portion of a balloon lobe of the balloon arrangement.[0072[ The method 900 may be similar to method 600 described above with respect to FIG. 6 and FIGS. 7A-7E, except as described below. For example, the exposing process (920) functions to prepare the fixation member 112 for its fixation in tissue at the target region, but when the lead body 110 is advanced distally (and / or the sheath 150 is retracted proximally), a stop (e.g., stop 160) is exposed in addition to the balloon arrangement 130 and fixation member 112. Furthermore, expanding one or more balloon lobes (930) may be similar to expanding the proximal and distal balloon lobes (630), except that the process of expanding a balloon lobe that is partially covered by the overhang of the stop primarily (at least initially) involves expansion of the balloon lobe in a distal direction, with reduced proximal and / or radial expansion of the portion of the balloon lobe that is covered by the overhang, as described in further detail above.Conclusion

[0073] Although many of the variations are described above largely with respect to systems, devices, and methods for positioning a cardiac pacing lead, the technology is applicable to other applications and / or other approaches, such as protecting tissue against other potentially tissue-engaging features (e.g., tines) of other types of leads such as neurostimulation leads. Moreover, other variations in addition to those described herein are within the scope ofthe technology. Additionally, several other variations of the technology can have different configurations, components, or procedures than those described herein. A person of ordinary skill in the art, therefore, will accordingly understand that the technology can have other variatoins with additional elements, or the technology can have other variations without several of the features shown and described above with reference to FIGS. 1-9.

[0074] The descriptions of variations of the technology are not intended to be exhaustive or to limit the technology to the precise form disclosed above. Where the context permits, singular or plural terms may also include the plural or singular term, respectively. Although specific variations of, and examples for, the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology, as those skilled in the relevant art will recognize. For example, while steps are presented in a given order, alternative variations may perform steps in a different order. The variations described herein may also be combined to provide further variations.

[0075] As used herein, the terms “generally,” “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values that would be recognized by those of ordinary skill in the art.

[0076] Moreover, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in reference to a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of the items in the list. Additionally, the term "comprising" is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and / or additional types of other features are not precluded. It will also be appreciated that specific variations have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. Further, while advantages associated with certain variations of the technology have been described in the context of those variations, other variations may also exhibit such advantages, and not all variations need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other variations not expressly shown or described herein.

Claims

CLAIMSI / We claim:

1. A medical lead system, comprising: a lead body having a distal end portion; a fixation member coupled to a distal end portion of the lead body; a balloon arrangement coupled to the lead body and comprising a proximal balloon lobe and a distal balloon lobe, each balloon lobe having a contracted configuration and an expanded configuration, wherein when the proximal and distal balloon lobes are in their expanded configurations, the proximal balloon lobe is configured to urge the distal balloon lobe in a distal direction to at least partially cover the fixation member.

2. The medical lead system of claim 1, wherein when the distal balloon lobe is in the expanded configuration, the distal balloon lobe is configured to extend distally beyond the fixation member.

3. The medical lead system of claim 1 or 2, wherein when the distal balloon lobe is in the expanded configuration, the distal balloon lobe is configured to substantially circumferentially surround the fixation member.

4. The medical lead system of any one of claims 1-3, wherein the balloon arrangement comprises a single balloon comprising the proximal balloon lobe and the distal balloon lobe.

5. The medical lead system of any one of claims 1-3, wherein the balloon arrangement comprises a distal balloon comprising the distal balloon lobe and a proximal balloon comprising the proximal balloon lobe.

6. The medical lead system of any one of claims 1-5, further comprising a cinch configured to circumferentially restrain the balloon arrangement between the proximal balloon lobe and distal balloon lobe.

7. The medical lead system of claim 6, wherein the cinch comprises a material with lower elasticity compared to the proximal balloon lobe and the distal balloon lobe.

8. The medical lead system of claim 6 or 7, wherein the cinch comprises a metal ring.

9. The medical lead system of any one of claims 6-8, wherein the cinch comprises a region of balloon material having lower elasticity compared to the proximal balloon lobe and the distal balloon lobe.

10. The medical lead system of any one of claims 1-9, wherein the lead body comprises a balloon shaft portion comprising at least one inflation port in fluidic communication with at least one of the proximal balloon lobe or distal balloon lobe.

11. The medical lead system of claim 10, wherein the balloon shaft portion comprises a first inflation port in fluidic communication with the proximal balloon lobe, and a second inflation port in fluidic communication with the distal balloon lobe.

12. The medical lead system of any one of claims 1-11, wherein the fixation member comprises a helical anchor.

13. The medical lead system of any one of claims 1-12, wherein the fixation member comprises an electrode configurable as a sensing electrode, a stimulation electrode, or both.

14. The medical lead system of claim 13, wherein the lead body is a cardiac pacing lead and the medical lead system further comprises a proximal connector configured to mechanically and electrically couple the cardiac pacing lead to an electrical stimulation device.

15. A medical lead system, comprising: a lead body having a distal end portion; a fixation member coupled to a distal end portion of the lead body; a balloon arrangement coupled to the lead body and comprising one or more balloon lobes having a contracted configuration and an expanded configuration; anda stop coupled to the lead body and comprising an inner stop surface and an outer stop surface, wherein the outer stop surface extends distally beyond the inner stop surface so as to form an overhang that is positioned around a proximal portion of the balloon arrangement; wherein when the one or more balloon lobes are in their expanded configurations, the stop is configured to urge the balloon arrangement in a distal direction to at least partially cover the fixation member.

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