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WO2024023622A1 - Dispositif de fixation de dispositif médical à élément anti-rotation - Google Patents

Dispositif de fixation de dispositif médical à élément anti-rotation Download PDF

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Publication number
WO2024023622A1
WO2024023622A1 PCT/IB2023/057195 IB2023057195W WO2024023622A1 WO 2024023622 A1 WO2024023622 A1 WO 2024023622A1 IB 2023057195 W IB2023057195 W IB 2023057195W WO 2024023622 A1 WO2024023622 A1 WO 2024023622A1
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WO
WIPO (PCT)
Prior art keywords
electrode
helix
tissue
examples
distal end
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/IB2023/057195
Other languages
English (en)
Inventor
Ronald A. Drake
Jonathan Baxter
Nathan A. Grenz
Jay T. Rassat
Lester O. Stener
Thomas A. Anderson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Medtronic Inc
Original Assignee
Medtronic Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Medtronic Inc filed Critical Medtronic Inc
Priority to EP23751087.0A priority Critical patent/EP4561669A1/fr
Priority to CN202380052390.4A priority patent/CN119497640A/zh
Publication of WO2024023622A1 publication Critical patent/WO2024023622A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/02—Details
    • A61N1/04—Electrodes
    • A61N1/05—Electrodes for implantation or insertion into the body, e.g. heart electrode
    • A61N1/056—Transvascular endocardial electrode systems
    • A61N1/057—Anchoring means; Means for fixing the head inside the heart
    • A61N1/0573—Anchoring means; Means for fixing the head inside the heart chacterised by means penetrating the heart tissue, e.g. helix needle or hook
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/18—Applying electric currents by contact electrodes
    • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
    • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
    • A61N1/372—Arrangements in connection with the implantation of stimulators
    • A61N1/375—Constructional arrangements, e.g. casings
    • A61N1/37518—Anchoring of the implants, e.g. fixation

Definitions

  • the disclosure relates to medical devices, and more particularly to fixation of medical devices.
  • IMDs implantable medical devices
  • Such IMDs may be adapted to monitor or treat conditions or functions relating to heart, muscle, nerve, brain, stomach, endocrine organs or other organs and their related functions.
  • IMDs may be associated with leads that position electrodes at a desired location, or may be leadless with electrodes integrated with and/or attached to the device housing.
  • These IMDs may have the ability to wirelessly transmit data either to another device implanted in the patient or to another instrument located externally of the patient, or both.
  • a cardiac pacemaker is an IMD configured to deliver cardiac pacing therapy to restore a more normal heart rhythm. Such IMDs sense the electrical activity of the heart, and deliver cardiac pacing based on the sensed electrical activity, via electrodes. Some cardiac pacemakers are implanted a distance from the heart and coupled to one or more leads that intravascularly extend into the heart to position electrodes with respect to cardiac tissue. Some cardiac pacemakers are sized to be completely implanted within one of the chambers of the heart and may include electrodes integrated with or attached to the device housing rather than leads. Some cardiac pacemakers provide dual chamber functionality, by sensing and/or stimulating the activity of both atria and ventricles, or other multi-chamber functionality. A cardiac pacemaker may provide multi-chamber functionality via leads that extend to respective heart chambers, or multiple cardiac pacemakers may provide multi-chamber functionality by being implanted in respective chambers.
  • this disclosure is directed to configurations of fixation devices of implantable medical devices. More particularly, this disclosure is directed to implantable medical devices having fixation devices that include one or more anti-rotation features that may resist rotation and/or dislodgement of the device, e.g., due to movement of heart tissue into which the device has been fixated.
  • the fixation device includes a helix that is rotated into tissue, and the anti-rotation features resist counterrotation of the helix out of the tissue.
  • these fixation devices are embodied as one or more electrode of the implantable medical device.
  • a single implantable medical device implanted in one chamber that is able to sense in and/or deliver cardiac pacing to more than one chamber, which may avoid the need for a leaded device or multiple smaller devices to provide such functionality, which may reduce the amount of material implanted within the patient.
  • such an implantable medical device includes a first electrode that is configured to penetrate through wall tissue of the heart chamber in which the device is implanted, and into wall tissue of another heart chamber.
  • the device includes a second electrode configured to contact the wall tissue of the chamber in which the device is implanted, e.g., without penetration of the wall tissue.
  • the electrodes can be connected to a distal end of the device.
  • the first electrode may be a helix including one or more anti-rotation features that prevents rotation of the device.
  • anti-rotation features in such implantable medical devices may prevent or reduce counter-rotation that may cause the first electrode and second electrode to lose contact with their respective intended cardiac tissue.
  • this disclosure is directed to a fixation device comprising: a first elongated body configured to extend distally from a distal end of an implantable medical device, the first elongated body comprising: a distal end configured to penetrate into tissue of a patient; and a helix having one or more coils, wherein at least one of the one or more coils defines an anti-rotation feature configured to resist rotation of the helix within the tissue; and a second elongated body configured to extend from the distal end of the implantable medical device, wherein the second elongated body is separate from the first elongated body.
  • this disclosure is directed to a device comprising: an elongated housing that extends from a proximal end of the housing to a distal end of the housing, the elongated housing configured to be implanted wholly within a first chamber of a heart, the first chamber of the heart having wall tissue; a first electrode extending distally from the distal end of the elongated housing, the first electrode comprising: a distal end of the first electrode configured to penetrate from the first chamber into wall tissue of a second chamber of the heart that is separate from the first chamber; and a first elongated body defining a helix extending to the distal end of the first electrode, the helix having an anti-rotation feature configured to resist rotation of the first electrode within the wall tissue of the second chamber or the wall tissue of the first chamber; a second electrode extending from the distal end of the elongated housing, wherein the second electrode is separate from the first electrode; a second elongated body extending distally from
  • this disclosure is directed to a method comprising: delivering cardiac pacing from a device to a heart, wherein the device comprises: an elongated housing extending from a proximal end of the housing to a distal end of the housing, the elongated housing configured to be implanted wholly within a first chamber of the heart, the first chamber of the heart having wall tissue; a first electrode extending distally from the distal end of the elongated housing, the first electrode comprising: a distal end of the first electrode is configured to penetrate into wall tissue of a second chamber of the heart that is separate from the first chamber of the heart; and a first elongated body defining a helix, the helix having an anti-rotation feature configured to resist rotation of the first electrode within the wall tissue of the second chamber; a second electrode extending from the distal end of the elongated housing, wherein the second electrode is separate from the first electrode; and a second elongated body configured to extend from the
  • this disclosure is directed to: a method comprising: forming a first elongated body into one or more coils of a helix, wherein at least one of the one or more coils defines a anti-rotation feature configured to resist rotation of the helix within tissue of a patient; disposing the helix onto a distal end of an implantable medical device such that the helix extends distally from the distal end; and disposing a second elongated body on to the distal end of the implantable medical device, wherein the second elongated body is separate from the first elongated body, and wherein the second elongated body is configured to flexibly maintain contact with the tissue without penetrating the tissue.
  • this disclosure is directed to a fixation device comprising: a first elongated body configured to extend distally from a distal end of an implantable medical device, the first elongated body comprising: a distal end configured to penetrate into tissue of a patient; and a helix having one or more coils, wherein at least one of the one or more coils defines an anti-rotation feature configured to resist rotation of the helix within the tissue, wherein the anti-rotation feature comprises a lobed geometric shape, and wherein the helix defines a plurality of lobes configured to form the lobed geometric shape.
  • this disclosure is directed to a fixation device comprising: a first elongated body configured to extend distally from a distal end of an implantable medical device, the first elongated body comprising: a distal end configured to penetrate into tissue of a patient; and a helix having one or more coils, the helix comprising a distal portion, a medial portion, and a proximal portion; and an anti-rotation feature defined by the one or more coils, the anti-rotation feature configured to resist rotation of the helix within the tissue, wherein the anti-rotation feature comprises the medial portion having a smaller diameter than the distal portion and the proximal portion.
  • this disclosure is directed to a fixation device comprising: a first elongated body configured to extend distally from a distal end of an implantable medical device, the first elongated body comprising: a distal end configured to penetrate into tissue of a patient; and a helix having one or more coils, the helix comprising a distal portion, a medial portion, and a proximal portion; and an anti-rotation feature defined by the one or more coils, the anti-rotation feature configured to resist rotation of the helix within the tissue, wherein the anti-rotation feature comprises the medial portion having a smaller pitch than the distal portion and the proximal portion.
  • this disclosure is a fixation device comprising: a first elongated body configured to extend distally from a distal end of an implantable medical device, the first elongated body comprising: a distal end configured to penetrate into tissue of a patient; and a helix having one or more coils; and an anti-rotation feature defined by the one or more coils, the anti-rotation feature configured to resist rotation of the helix within the tissue, wherein the anti-rotation feature comprises a varying pitch of the helix, the varying pitch resulting from an undulating configuration of the one or more coils of the helix.
  • FIG. 1 is a conceptual drawing illustrating an example device implanted in the heart of a patient, in accordance with one or more aspects of this disclosure.
  • FIG. 2 is a perspective drawing illustrating the example device of FIG. 1, in accordance with one or more aspects of this disclosure.
  • FIG. 3 is a functional block diagram illustrating an example configuration of the IMD of FIGS. 1 and 2, in accordance with one or more aspects of this disclosure.
  • FIG. 4 is a conceptual diagram of the device of FIGS. 1-3 implanted at a target implant site.
  • FIGS. 5 A, 5B, and 5C are partial views of the device of FIGS. 1-4 from different perspectives, in accordance with one or more aspects of this disclosure.
  • FIGS. 6A, 6B, 6C, and 6D are conceptual diagrams illustrating top-down views of the first electrode of the example device of FIG. 5C.
  • FIG. 7 is a conceptual diagram illustrating another example anti-rotation feature of the example device of FIGS. 1-4.
  • FIG. 8 is a conceptual diagram illustrating another example anti-rotation feature of the example device of FIGS. 1-4.
  • FIGS. 9A is a conceptual diagram illustrating different views of another example anti-rotation feature of the example device of FIGS. 1-4.
  • FIG. 9B is a conceptual diagram illustrating a top-down view of the first electrode of the example device 104 of FIG. 9A.
  • FIG. 10 is a flow diagram illustrating an example process for deploying an example device.
  • FIG. 11 is a flow diagram illustrating an example process for manufacturing the example anti-rotation feature of an example device.
  • FIG. 12 is a flow diagram illustrating another example process for manufacturing the example anti-rotation feature of the example device.
  • this disclosure is directed to configurations of fixation devices of implantable medical devices. More particularly, this disclosure is directed to implantable medical devices having fixation devices that include one or more anti-rotation features that may resist rotation and/or dislodgement of the device, e.g., due to movement of heart tissue into which the device has been fixated. The anti-rotation features may resist counter-rotation of the fixation devices out of the tissue.
  • FIG. 1 is a conceptual drawing illustrating an example device 104 implanted in the heart 102 of a patient, in accordance with one or more aspects of this disclosure.
  • Device 104 is shown implanted in the right atrium (RA) of the patient’s heart 102 in a target implant region 106, such as triangle of Koch, in heart 102 of the patient with a distal end of device 104 directed toward the left ventricle (LV) of the patient’s heart 102.
  • RA right atrium
  • LV left ventricle
  • Target implant region 106 may lie between the bundle of His and the coronary sinus and may be adjacent the tricuspid valve.
  • Device 104 includes a distal end 110 and a proximal end 116.
  • Distal end 110 includes a first electrode 112 and a second electrode 114.
  • First electrode 112 extends from distal end 110 and may penetrate through the wall tissue of a first chamber (e.g., the RA in the illustrated example) into wall tissue of a second chamber (e.g., ventricular myocardium 108 of the LV in the illustrated example).
  • Second electrode 114 extends from distal end 110 and is configured to flexibly maintain contact with the wall tissue of the first chamber without penetration of the wall tissue of the first chamber by the second electrode.
  • First electrode 112 may define a helical shape, e.g., as illustrated in FIG. 1.
  • First electrode 112 may further define one or more anti- rotation features configured to prevent rotation and dislodgment of the wall tissue of heart 102.
  • the one or more anti-rotation features may include one or more of a shape and/or dimensions of the helical shape of first electrode 112.
  • the one or more anti-rotation features may include additional anti -rotation features (e.g., tines or the like) disposed on first electrode 112.
  • the configuration of electrodes 112 and 114 illustrated in FIG. 1 allows device 104 to sense cardiac signals and/or deliver cardiac pacing to multiple chambers of heart 102, e.g., the RA and ventricles in the illustrated example.
  • the configuration of electrodes 112 and 114 may facilitate the delivery of A-V synchronous pacing by single device 104 implanted within the single chamber, e.g., the RA. While device 104 is implanted at target implant region 106 to sense in and/or pace the RA and ventricles in the example shown in FIG.
  • a device having an electrode configuration in accordance with the examples of this disclosure may be implanted at any of a variety of locations to sense in and/or pace any two or more chambers of heart 102.
  • device 104 may be implanted at region 106 or another region, and first electrode 112 may extend into tissue, e.g., myocardial tissue, of the LV or interventricular septum to, for example, facilitate the delivery of A-V synchronous pacing.
  • a device having an electrode configuration in accordance with the examples of this disclosure may be implanted at any of a variety of locations within a patient for sensing and/or delivery of therapy to other patient tissue.
  • the anti-rotation features described herein are described primarily in the context of a cardiac pacemaker configured to be implanted in one chamber and deliver pacing and sense in that chamber and an additional chamber. However, the antirotation features described herein may be included on any fixation element on any implantable medical device, such as an implantable stimulator or implantable lead configured to be fixed at any location or tissue of the body.
  • FIG. 2 is a perspective drawing illustrating device 104.
  • Device 104 includes a housing 202 that defines a hermetically sealed internal cavity.
  • Housing 202 may be formed from a conductive material including titanium or titanium alloy, stainless steel, MP35N (a non-magnetic nickel-cobalt-chromium-molybdenum alloy), platinum alloy or other bio-compatible metal or metal alloy, or other suitable conductive material.
  • housing 202 is formed from a non-conductive material including ceramic, glass, sapphire, silicone, polyurethane, epoxy, acetyl co-polymer plastics, poly ether ether ketone (PEEK), a liquid crystal polymer, other biocompatible polymer, or other suitable non- conductive material.
  • PEEK poly ether ether ketone
  • Housing 202 extends between distal end 204 and proximal end 206.
  • housing can be cylindrical or substantially cylindrical but may be other shapes, e.g., prismatic, or other geometric shapes.
  • Housing 202 may include a delivery tool interface member 208, e.g., at proximal end 206, for engaging with a delivery tool during implantation of device 104.
  • delivery tool interface member 208 e.g., at proximal end 206
  • housing 202 may define a face of housing 202. The face of housing 202 may be orthogonal to longitudinal axis 212.
  • Electrode 210 may function as an electrode 210, e.g., an anode, during pacing and/or sensing.
  • electrode 210 can circumscribe a portion of housing 202 at or near proximal end 206. Electrode 210 can fully or partially circumscribe housing 202. FIG. 2 shows electrode 210 extending as a singular band. Electrode 210 can also include multiple segments spaced a distance apart along a longitudinal axis 212 of housing 202 and/or around a perimeter of housing 202.
  • housing 202 When housing 202 is formed from a conductive material, such as a titanium alloy, portions of housing 202 may be electrically insulated by a non-conductive material, such as a coating of parylene, polyurethane, silicone, epoxy or other biocompatible polymer, or other suitable material. For the portions of housing 202 without the non- conductive material, one or more discrete areas of housing 202 with conductive material can be exposed to define electrode 210.
  • a non-conductive material such as a coating of parylene, polyurethane, silicone, epoxy or other biocompatible polymer, or other suitable material.
  • housing 202 is formed from a non-conductive material, such as a ceramic, glass or polymer material, an electrically-conductive coating or layer, such as a titanium, platinum, stainless steel, alloys thereof, a conductive material may be applied to one or more discrete areas of housing 202 to form electrode 210.
  • a non-conductive material such as a ceramic, glass or polymer material
  • an electrically-conductive coating or layer such as a titanium, platinum, stainless steel, alloys thereof
  • a conductive material may be applied to one or more discrete areas of housing 202 to form electrode 210.
  • electrode 210 may be a component, such as a ring electrode, that is mounted or assembled onto housing 202. Electrode 210 may be electrically coupled to internal circuitry of device 104 via electrically-conductive housing 202 or an electrical conductor when housing 202 is a non-conductive material. In some examples, electrode 210 is located proximate to proximal end 206 of housing 202 and can be referred to as a proximal housing-based electrode. Electrode 210 can also be located at other positions along housing 202, e.g., located proximately to distal end 204 or at other positions along longitudinal axis 212.
  • first electrode 112 and second electrode 114 extends from a first end that is fixedly attached to housing 202 at or near distal end 204, to a second end that, in the example of FIG. 2, is not attached to housing 202 other than via the first end (e.g., is a free end).
  • First electrode 112 includes one or more coatings configured to define a first electrically active region 216 and second electrode 114 includes one or more coatings configured to define a second electrically active region 218.
  • first electrically active region 216 may be more proximate to the second, e.g., distal, end of first electrode 112 and second electrically active region 218 may be proximate to either end of second electrode 114.
  • first electrically active region 216 includes the distal end of electrode 112.
  • First and second electrodes 112 and 114 may be formed of an electrically conductive material, such as titanium, platinum, iridium, tantalum, or alloys thereof. First and second electrodes 112 and 114 may be coated with an electrically insulating coating, e.g., a parylene, polyurethane, silicone, epoxy, or other insulating coating, to reduce the electrically conductive active surface area of first and second electrodes 112 and 114, and thereby define first and second electrically active regions 216 and 218.
  • an electrically insulating coating e.g., a parylene, polyurethane, silicone, epoxy, or other insulating coating
  • first and second electrically active regions 216 and 218 by covering portions with an insulating coating may increase the electrical impedance of first and second electrodes 112 and 114 and thereby reduce the current delivered during a pacing pulse that captures the cardiac tissue.
  • a lower current drain conserves the power source, e.g., one or more rechargeable or non-rechargeable batteries, of device 104.
  • first and second electrodes 112 and 114 may have an electrically conducting material coating on first and second electrically active regions 216 and 218 to define the active regions.
  • first and second electrically active regions 216 and 218 may be coated with titanium nitride (TiN).
  • TiN titanium nitride
  • First and second electrodes 216 and 218 may be made of substantially similar material or may be made of different material from one another.
  • first electrode 112 takes the form of a helix.
  • a helix is an object having a three-dimensional shape like that of a wire wound uniformly in a single layer around a cylindrical or conical surface such that the wire would be in a straight line if the surface were unrolled into a plane.
  • Second electrode 114 includes a ramp portion, which may be configured as a partial helix, e.g., a helix that does not make a full revolution around a circumference of the cylindrical or conical surface.
  • First electrode 112 may define one or more anti-rotation features along length of first electrode 112.
  • the one or more anti-rotation features may prevent rotation of first electrode 112 within the tissue of heart 102, e.g., by increasing friction between first electrode 112 and the tissue.
  • the one or more anti-rotation features e.g., the friction or other fixation force provided by the features, may be sufficient to resist rotation of first electrode 112 by movement of the tissue of heart 102, but may not be sufficient to resist rotation of first electrode 112 by the clinician, e.g., to remove device 104 from heart 102.
  • the one or more anti-rotation features may resist forces of up to about 5 Ounce-force inches (ozf.
  • the amount of force the tissue is exerting on first electrode 112 may vary based on movement of heart 102, movement of device 104, movement of fluid within heart 104, size of heart 102, or the like.
  • the one or more anti-rotation features may include a shape of first electrode 112, dimensions (e.g., outer diameter, pitch, or the like) of first electrode 112, and/or one or more other characteristics of first electrode 112.
  • the one or more anti-rotation features include a geometric shape of first electrode 112, a multi-diameter configuration of first electrode 112, a multi-pitch configuration of first electrode 112, a waveform configuration of first electrode 112, or any combination herein.
  • first electrode 112 may include one or more anti-rotation features disposed on an outer surface of first electrode 112.
  • the one or more anti-rotation features disposed on first electrode 112 may include, but are not limited to, elongate darts, barbs, or tines.
  • the one or more anti-rotation features may resist rotation of first electrode 112 (e.g., by penetrating the tissue, by increase the friction between first electrode 112 and the tissue, or the like).
  • first electrode 112 may be a right-hand wound helix
  • second electrode 114 may be a left-hand wound partial helix, although in other examples the handedness of the electrodes may be switched or the electrodes may have the same handedness as each other.
  • the helix of first electrode 112 may be wound in a same direction as the partial helix of second electrode 114.
  • the helix and partial helix defined by first electrode 112 and second electrode 118, respectively have the same pitch, although they may have different pitches in other examples.
  • first electrode 112 has a varying pitch along longitudinal axis 212.
  • first electrode 112 and 114 may have a shape other than helical.
  • first electrode 112 may have a geometrical shape (e.g., a triangular shape, a rectangular shape, a hexagonal shape, an octagonal shape, a lobed shape, or the like). The varying shape and/or pitch may cause first electrode 112 to resist rotation within the tissue of heart 102.
  • First and second electrodes 112 and 114 can also vary in size and shape in order to enhance tissue contact of first and second electrically active regions 216 and 218.
  • first and second electrodes 112 and 114 can have a round cross section or could be made with a flatter cross section (e.g., oval or rectangular) based on tissue contact specifications.
  • the size and shape of first and second electrodes 112 and 114 can also be determined by stiffness requirements. For example, stiffness requirements may vary based on the expected implantation requirements, including the tissue into which the electrodes are implanted or contact, as well as how long device 104 is intended to be implanted.
  • the distal end of first electrode 112 can have a conical, hemi-spherical, or slanted edge distal tip with a narrow tip diameter, e.g., less than 1 millimeter (mm), for penetrating into and through tissue layers.
  • the distal end of first electrode can be a sharpened or angular tip or sharpened or beveled edges, but the degree of sharpness may be constrained to avoid a cutting action that could lead to lateral displacement of the distal end of first electrode 112 and undesired tissue trauma.
  • the helix of first electrode 112 may have a maximum diameter at its base that interfaces with housing distal end 204.
  • first electrode 112 may decrease from housing distal end 204 to the distal end of first electrode 112. In some examples, the diameter of first electrode 112 may vary from housing distal end 204 to the distal end of first electrode 112. The varying diameter may cause first electrode 112 to resist rotation within the tissue of heart 102.
  • first electrode 112 can be substantially straight and cylindrical, with first electrode 112 being rigid in some examples.
  • first and second electrodes 112 and 114 can have flexibility in lateral directions, being non- rigid to allow some flexing with heart motion. In a relaxed state, when not subjected to any external forces, first and second electrodes 112 and 114 can be configured to maintain a distance between first and second electrically active regions 216 and 218 and housing distal end 204.
  • first electrode 112 can pierce through one or more tissue layers to position first electrically active region 216 within a desired tissue layer, e.g., the ventricular myocardium 108 or interventricular septum. Accordingly, first electrode 112 extends a distance from housing distal end 204 corresponding to the expected pacing site depth and may have a relatively high compressive strength along its longitudinal axis, which may be substantially similar to longitudinal axis 212, to resist bending in a lateral or radial direction when a longitudinal, axial, and/or rotational force is applied, e.g., to the proximal end 206 of housing 202 to advance device 104 into the tissue at target implant region 106.
  • first electrode 112 By resisting bending in a lateral or radial direction, first electrode 112 can maintain a spacing between a plurality of windings of first electrode 112 when first electrode 112 is a helix electrode. The spacing may be a pre-determined pitch of first electrode 112 and may vary from distal end 204 to the distal end of first electrode 112.
  • First electrode 112 may be longitudinally non-compressive. First electrode 112 may also be elastically deformable in lateral or radial directions when subjected to lateral or radial forces, however, to allow temporary flexing, e.g., with tissue motion, but returns to its normally straight position when lateral forces diminish. In some examples, when first electrode 112 is not exposed to any external force, or to only a force along its longitudinal axis (substantially similar to longitudinal axis 212), first electrode 112 retains a straight, linear position as shown.
  • second electrode 114 or electrode 210 may be paired with first electrode 112 for sensing ventricular signals and delivering ventricular pacing pulses.
  • second electrode 114 may be paired with electrode 210 or first electrode 112 for sensing atrial signals and delivering pacing pulses to atrial tissue (e.g., atrial myocardium) in target implant region 106.
  • atrial tissue e.g., atrial myocardium
  • electrode 210 may be paired, at different times, with both first electrode 112 and second electrode 114 for either ventricular or atrial functionality, respectively, in some examples.
  • first and second electrodes 112 and 114 may be paired with each other, with different polarities, for atrial and ventricular functionality.
  • second electrode 114 may be configured as an atrial cathode electrode for delivering pacing pulses to the atrial tissue at target implant region 106 in combination with electrode 210. Second electrode 114 and electrode 210 may also be used to sense atrial P-waves for use in controlling atrial pacing pulses (delivered in the absence of a sensed P-wave) and for controlling atrial- synchronized ventricular pacing pulses delivered using first electrode 112 as a cathode and electrode 210 as the return anode.
  • device 104 includes a distal fixation assembly 214 including first electrode 112, second electrode 114, and housing distal end 204.
  • a distal end of first electrode 112 can be configured to rest within a ventricular myocardium of the patient, and second electrode 114 can be configured to contact an atrial endocardium of the patient.
  • distal fixation assembly 214 can include more or less electrodes than two electrodes.
  • distal fixation assembly 214 may include one or more second electrodes along housing distal end 204.
  • distal fixation assembly 214 may include three electrodes configured for atrial functionality like second electrode 114, and the three electrodes may be substantially similar or different from one another.
  • Second electrode(s) 114 may be individually selectively coupled to sensing and/or pacing circuitry enclosed by housing 202 for use as an anode with first electrode 112 or as an atrial cathode electrode, or may be electrically common and not individually selectable.
  • Second electrode 114 is configured to flexibly maintain contact with wall tissue of the heart chamber in which device 104 is implanted, e.g., the RA endocardium, despite variations in the tissue surface or in the distance between distal end 204 of housing 202 and the tissue surface, which may occur as the wall tissue moves during the cardiac cycle.
  • second electrode 114 may be flexible and configured to have spring-like properties.
  • second electrode 114 may be configured to elastically deform, e.g., toward distal end 204 of housing 202, but may be spring biased toward a resting configuration and, when elastically deformed, the spring bias may urge the second electrode away from distal end 204 of housing 202. In this manner, the elastic deformation and spring bias may maintain the second electrode in consistent contact with the wall tissue of the chamber in which the device is implanted.
  • an electrode being moveable with respect to housing 202.
  • an electrode may be configured to elastically deform as described above.
  • an electrode may additionally be attached to housing 202 by, or may include, a mechanism, such as a spring or joint, that allows relative motion of the electrode to housing 202. In such examples, the electrode need not itself be deformable.
  • FIG. 3 is a functional block diagram illustrating an example configuration of device 104.
  • device 104 include electrodes 112 and 114, which may be configured as described with respect to FIGS. 1 and 2.
  • first electrode 112 may be configured to extend from distal end 204 of housing 202 and may penetrate through the wall tissue of a first chamber (e.g., the RA) into wall tissue of a second chamber (e.g., the LV).
  • Second electrode 114 extends from distal end 204 of housing 202 and is configured to flexibly maintain contact with the wall tissue of the first chamber without penetration of the wall tissue of the first chamber by the second electrode.
  • device 104 includes switch circuitry 302, sensing circuitry 304, signal generation circuitry 306, sensor(s) 308, processing circuitry 310, telemetry circuitry 312, memory 314, and power source 316.
  • the various circuitry may be, or include, programmable or fixed function circuitry configured to perform the functions attributed to respective circuitry.
  • Memory 314 may store computer-readable instructions that, when executed by processing circuitry 310, cause device 104 to perform various functions.
  • Memory 314 may be a storage device or other non-transitory medium.
  • the components of device 104 illustrated in FIG. 3 may be housed within housing 202.
  • Signal generation circuitry 306 generates electrical stimulation signals, e.g., cardiac pacing pulses.
  • Switch circuitry 302 is coupled to electrodes 112, 114, and 210, may include one or more switch arrays, one or more multiplexers, one or more switches (e.g., a switch matrix or other collection of switches), one or more transistors, or other electrical circuitry.
  • Switch circuitry 302 is configured to direct stimulation signals from signal generation circuitry 306 to a selected combination of electrodes 112, 114, and 210, having selected polarities, e.g., to selectively deliver pacing pulses to the RA, ventricles, or interventricular septum of heart 102.
  • switch circuitry 302 may couple first electrode 112, which has penetrated to wall tissue of a ventricle or the intraventricular septum, to signal generation circuitry 306 as a cathode, and one or both of second electrode 114 or electrode 210 to signal generation circuitry 306 as an anode.
  • switch circuitry 302 may couple second electrode 114, which flexibly maintains contact with the RA endocardium, to signal generation circuitry 306 as a cathode, and one or both of first electrode 112 or electrode 210 to signal generation circuitry 306 as an anode.
  • Switch circuitry 302 may also selectively couple sensing circuitry 304 to selected combinations of electrodes 112, 114, and 210, e.g., to selectively sense the electrical activity of either the RA or ventricles of heart 102.
  • Sensing circuitry 304 may include filters, amplifiers, analog-to-digital converters, or other circuitry configured to sense cardiac electrical signals via electrodes 112, 114, and/or 210.
  • switch circuitry 302 may couple each of first electrode 112 and second electrode 114 (in combination with electrode 210) to respective sensing channels provided by sensing circuitry 304 to respectively sense either ventricular or atrial cardiac electrical signals.
  • sensing circuitry 304 is configured to detect events, e.g., depolarizations, within the cardiac electrical signals, and provide indications thereof to processing circuitry 310. In this manner, processing circuitry 310 may determine the timing of atrial and ventricular depolarizations, and control the delivery of cardiac pacing, e.g., AV synchronized cardiac pacing, based thereon.
  • cardiac pacing e.g., AV synchronized cardiac pacing
  • Processing circuitry 310 may include any one or more of a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), discrete logic circuitry, or any other processing circuitry configured to provide the functions attributed to processing circuitry 310 herein may be embodied as firmware, hardware, software or any combination thereof.
  • DSP digital signal processor
  • ASIC application specific integrated circuit
  • FPGA field-programmable gate array
  • Sensor(s) 308 may include one or more sensing elements that transduce patient physiological activity to an electrical signal to sense values of a respective patient parameter.
  • Sensor(s) 308 may include one or more accelerometers, optical sensors, chemical sensors, temperature sensors, pressure sensors, or any other types of sensors.
  • Sensor(s) 308 may output patient parameter values that may be used as feedback to control sensing and delivery of therapy by device 104.
  • Telemetry circuitry 312 supports wireless communication between device 104 and an external programmer (not shown in FIG. 3) or another computing device (e.g., another implanted device such as, but is not limited to an implantable pulse generator (IPG) or an implantable cardiac defibrillator (ICD) under the control of processing circuitry 310.
  • processing circuitry 310 of device 104 may receive, as updates to operational parameters from the computing device, and provide collected data, e.g., sensed heart activity or other patient parameters, via telemetry circuitry 312.
  • Telemetry circuitry 312 may accomplish communication by radiofrequency (RF) communication techniques, e.g., via an antenna (not shown).
  • RF radiofrequency
  • Power source 316 delivers operating power to various components of device 104.
  • Power source 316 may include a rechargeable or non-rechargeable battery and a power generation circuit to produce the operating power. Recharging may be accomplished through proximal inductive interaction between an external charger and an inductive charging coil within device 104.
  • FIG. 4 is a conceptual diagram of device 104 implanted at target implant region 106.
  • First electrode 112 may be inserted such that tissue becomes engaged with the helix of first electrode 112. As first electrode 112 becomes engaged with tissue, first electrode 112 pierces into the tissue at target implant region 106 and advances through atrial myocardium 406 and central fibrous body 402 to position first electrically active region 216 in ventricular myocardium 108 as shown in FIG. 4. In some examples, first electrode 112 penetrates into the interventricular septum. In some examples, first electrode 112 does not perforate entirely through the ventricular endocardial or epicardial surface.
  • manual pressure applied to the housing proximal end 206 e.g., via an advancement tool, provides the longitudinal force to pierce the cardiac tissue at target implant region 106.
  • actuation of an advancement tool rotates device 104 and first electrode 112 configured as a helix about longitudinal axis 212. The rotation of the helix about the longitudinal axis 212 advances first electrode 112 through atrial myocardium 406 and central fibrous body 402 to position first electrically active region 216 in ventricular myocardium 108 as shown in FIG. 4.
  • First electrode 112 may define one or more anti-rotation features, e.g., as illustrated and described in greater detail with respect to FIGS. 6A-9.
  • the one or more anti-rotation features may prevent rotation of first electrode 112 within the cardiac tissue at target implant region 106.
  • the one or more anti-rotation features may increase friction between first electrode 112 and the cardiac tissue at target implant region 106 by a predetermined amount. The pre-determined increase in friction may prevent rotation of first electrode 112 due to movement of the cardiac tissue but may not prevent rotation of first electrode 112 due to manual pressure applied to the housing proximal end 206, e.g., via the advancement tool.
  • Second electrode 114 is held in contact with atrial endocardium 404 by first electrode 112, e.g., retraction of second electrode 114 from the surface of atrial endocardium 404 is prevented by first electrode 112. Second electrode 114 is also configured, as described herein, to flexibly maintain contact with atrial endocardium 404.
  • second electrode 114 is elastically deformable toward distal end 204 of housing 202 and has a spring bias urging second electrode 114 distally from distal end 204.
  • First electrode 112 can be the sole anti-rotation feature of device 104 in some examples. The distance first electrode 112 extends from housing 202 can be selected so first electrically active region 216 reaches an appropriate depth in the tissue layers to reach the targeted pacing and sensing site, in this case in ventricular myocardium 108, without puncturing all the way through into an adjacent cardiac chamber.
  • Target implant region 106 in some pacing applications is along atrial endocardium 404, substantially inferior to the AV node and bundle of His.
  • First electrode 112 can have a length that penetrates through atrial endocardium 404 in target implant region 106, through the central fibrous body 402 and into ventricular myocardium 108 without perforating through the ventricular endocardial surface. In some examples, when the full length of first electrode 112 is fully advanced into target implant region 106, first electrically active region 216 rests within ventricular myocardium 108 and second electrode 114 is positioned in intimate contact with atrial endocardium 404.
  • First electrode 112 may extend from housing distal end 204 approximately 3 mm to 12 mm in various examples.
  • first electrode 112 may extend a distance from housing 202 of at least 3 millimeters (mm), at least 3 mm but less than 20 mm, less than 15 mm, less than 10 mm, or less than 8 mm in various examples.
  • the diameter of first and second electrodes 112 and 114 may be less than 2 mm and may be 1 mm or less, or even 0.6 mm or less.
  • Inflammation of patient tissue may result from interaction with device 104.
  • penetration of tissue by a first electrode and/or contact between tissue and the second electrode may result in inflammation of the tissue.
  • Inflammation of patient tissue proximate to electrodes may result in higher thresholds for stimulation delivered to the tissue to activate, or capture, the tissue. Higher capture thresholds may, in turn, increase the consumption of a power source of the IMD associated with delivery of the stimulation.
  • an IMD as described herein, such as IMDs 104 may include one or more steroid eluting elements (e.g., disposed on the face of distal end 204). The steroid may mitigate inflammation of patient tissue resulting from interaction with the IMD.
  • the steroid eluting element(s) may be configured to elute one or more steroids to tissue in proximity to the element(s) over time.
  • the one or more steroid eluting elements comprise one or more monolithic controlled release devices (MCRDs).
  • MCRDs monolithic controlled release devices
  • an IMD includes one or both of a first steroid eluting element configured to elute one or more steroids to tissue proximate to the first electrode, and a second steroid eluting element configured to elute one or more steroids to tissue proximate to the second electrode.
  • IMD 104 includes a steroid eluting element at distal end 204 of housing 202, e.g., included with, attached to, or formed on header 502. The Steroid eluting element may elute one or more steroids to wall tissue proximate to second electrode 114.
  • FIGS. 5A, 5B, and 5C are partial views of the device of FIGS. 1-4 from different perspectives, in accordance with one or more aspects of this disclosure.
  • FIG. 5A is a partial view of distal end 110 of device 104 including distal fixation assembly 214.
  • Housing 202 includes a header 502.
  • header 502 may be separate or integral with housing 202 and can be made of the same or different materials as housing 202.
  • Housing distal end 204 e.g., header 502 or face 503 of distal end 204, defines a recess 504 (e.g., a recessed channel) to receive at least a portion of second electrode 114 as it is elastically deformed toward housing 202.
  • Second electrically active region 218 can maintain contact with the tissue surface when second electrode 114 is partially or fully deformed into recess 504.
  • second electrode 114 can maintain contact with tissue as the extent of deformation of second electrode 114 toward housing 202 varies.
  • Second electrode 114 may be spring biased to an undeformed position, and deformation of second electrode 114 proximally toward distal end 204 of housing 202 may result in a spring force directed distally from housing 202 that urges second electrode 114, and more particularly second electrically active region 218, against cardiac tissue.
  • deformation of second electrode 114 may vary with the motion of the heart. Because, at least in part, of the ability of the deformation of second electrode 114 to vary, e.g., during the cardiac cycle, second electrically active region 218 can maintain consistent contact with the tissue and provide pacing to the heart.
  • Second electrode 114 may extend from a first end 508 to a second end 510.
  • First end 508 may be connected to distal end 204 of housing 202.
  • second electrode 114 may extend distally from first end 508 toward second electrically active region 218.
  • Second end 510 may be connected to distal end 204 or may be a free end (e.g., free-floating).
  • FIG. 5B is a conceptual diagram of a partial view of device 104 with a cutaway to show a recessed hole 506, in accordance with one or more aspects of this disclosure.
  • FIGS. 5C is a conceptual diagram of a partial, side perspective view of device 104, in accordance with one or more aspects of this disclosure.
  • first end 508 of second electrode 114 is attached to header 502 and is connected (e.g., electrically) to a feedthrough.
  • a second end 510 of second electrode 114 is bent back towards device 104 and is able to move into recessed hole 506 as second electrode 114 is deformed.
  • second electrically active region 218 can maintain contact with tissue while second end 510 is pushed into recessed hole 506 due to deformation of second electrode 114 with heart motion.
  • first electrode 112 and second electrode 114 can have different handed helical shapes.
  • the helix of first electrode 112 can be a right-hand helix.
  • First electrode 112 can be inserted, e.g., in a manner similar to rotating and advancing a threaded screw, such that tissue becomes engaged with the helix of first electrode 112.
  • the partial helix of second electrode 114 can be a left-hand or a right-hand helix.
  • the tissue will gradually contact ramp portion 512 (illustrated in FIG. 5C) of second electrode 114 similar to advancing along a ramp, and the ramp-shape of ramp portion 512 will gradually deform, e.g., compress, toward housing 202.
  • first electrode 112 includes a helix with a first pitch
  • ramp portion 512 of second electrode 114 is a partial helix with a second pitch.
  • a first pitch of the helix of first electrode 112 can be the same, substantially similar, or different than the second pitch of the partial helix of second electrode 114.
  • second electrode 114 can be more peripheral than first electrode 112 relative to longitudinal axis 212.
  • first electrode 112 resides in an inner space defined by second electrode 114 and is approximately concentric with second electrode 114.
  • FIGS. 6A- 6D are conceptual diagrams respectively illustrating example top- down views of first electrode 112 of device 104 of FIG. 5C.
  • FIGS. 6A-D illustrate antirotation features including shapes 602A-602D (collectively, “shapes 602”).
  • FIGS. 6A-D illustrates shapes 602A-602D as a hexagonal shape, a rectangular shape, an octagonal shape, and a lobed shape, respectively.
  • shapes 602 may include one or more other geometrical shapes (e.g., triangular, heptagonal, oval, or the like).
  • Each of shapes 602 may be define by a plurality of sides 603 joined at a plurality of vertices 601.
  • Shapes 602 may resist rotation of first electrode 112 in the cardiac tissue. Shapes 602 may resist movement of first electrode 112 within a tunnel created by first electrode 112 during implantation due to one or more edges of shapes 602. The edges of shape 602 may contact the tissue around the tunnel created by first electrode 112 and increase resistance to movement of first electrode 112. Shapes 602 may be centered around longitudinal axis 212 and may have a width and/or diameter DI. The clinician may determine a value for DI based at least in part on the expected forces acting on first electrode 112 and the range of user-selected forces that first electrode 112 will resist. [0083] The lobed shape 602D, as illustrated in FIG.
  • each of protrusions 604 may extend radially outward at the center and extend radially inward at the edges.
  • Each of protrusions 604 may comprise an outward-pointing vertex 606 located between adjacent inwardpointing vertices 608.
  • Each of protrusions 604 may join adjacent protrusions 604 at the edges.
  • the edges of shape 602 may be curved.
  • the edges of shapes 602 and/or outward-pointing vertexes 606 may be sharpened, e.g., to facilitate penetration of the cardiac tissue by first electrode 112.
  • one or more coils of first electrode 112 may be out of radial phase with adjacent coils of first electrode 112.
  • the one or more coils may be For example, where shape 602 is a rectangular shape 602B, a vertex 601 of the first coil defining rectangular shape 602B may be up to 90 degrees apart from a corresponding vertex 601 of one or more of adjacent coils.
  • FIG. 7 is a conceptual diagram illustrating another example anti-rotation feature 702 of example device 104 of FIGS. 1-4.
  • Anti-rotation feature 702 includes a multi-diameter configuration of first electrode 112.
  • First electrode 112 extends distally from distal end 204 of housing 202 along longitudinal axis 212 and includes a plurality of portions.
  • FIG. 7 illustrates first electrode 112 including first portion 704 having outer diameter D2, second portion 706 having outer diameter D3, and third portion 708 having outer diameter D4.
  • first electrode 112 may include two portions or four or more portions. Each of the plurality of portions may correspond to one or more coils (e.g., one or more complete coils) of helix of first electrode 112.
  • first portion 704 may be connected to distal end 204 of housing 202 (e.g., to face 503 of housing 202). First portion 704 may extend distally from distal end 204 along longitudinal axis 212. Second portion 706 may be connected to first portion 704 and may extend distally from first portion 704. Third portion 708 may be connected to second portion 706 and may extend distally from second portion 706. First electrically active region 216 may be disposed on third portion 708.
  • outer diameters D2 and D4 may be greater than outer diameter D3, forming an hourglass configuration for first electrode 112.
  • first electrode 112 may compress cardiac tissue between the coils of first electrode and may resist movement of first electrode 112 (e.g., movement of third portion 708) along a tunnel within the cardiac tissue in a region defined by a portion with a smaller outer diameter (e.g., in a region defined by second portion 706).
  • outer diameters D3 and D4 may be greater than outer diameter D2 or outer diameters D2 and D3, may be greater than outer diameter D4.
  • outer diameters D2 and D4 may have a same outer diameter value that is greater than outer diameter D3. In some examples, outer diameters D2 and D4 may have different outer diameters values that are greater than outer diameter D3. The outer diameter values of D2, D3, and D4 may be user-selected to resist rotation of device 104 from a determined range of forces acting on device 104.
  • FIG. 8 is a conceptual diagram illustrating another example anti-rotation feature 802 of example device 104 of FIGS. 1 ⁇ 1.
  • Anti-rotation feature 802 may be a multipitch configuration for first electrode 112.
  • the helix of first electrode 112 may include a plurality of portions, each of the plurality of portions including one or more coils of the helix.
  • first electrode 112 may include first portion 804, second portion 806, third portion 808, and fourth portion 810 arranged along first electrode 112 from distal end 204 to the distal end of first electrode 112.
  • the plurality of portions may include two portions, three portions, or four or more portions. At least one portion of the plurality of portions may have a different pitch than another of the plurality of portions.
  • first portion 804 and fourth portion 810 defining the proximal and distal ends of first electrode 112, have a greater pitch than second portion 806 and third portion 808.
  • second portion 806 and third portion 808 may have a greater pitch than first portion 804 and fourth portion 810.
  • the pitch of first electrode 112 may increase and/or decrease from distal end 204 to the distal end of first electrode 112.
  • first electrode 112 with a different pitch may interfere with proximal movement of a portion of first electrode 112 within the tunnel and may prevent rotation of device 104.
  • fourth portion 810 retracts from the cardiac tissue, fourth portion 810 engages with portions of the tunnel corresponding to third portion 808 and encounters increased resistance due to the change in pitch.
  • a similar effect may occur as second portion 804 retracts proximally and engages with portions of the tunnel corresponding to first portion 802.
  • second electrode 114 may define a partial helix 710. Partial helix 710 may be wound in the same direction as first electrode 112.
  • FIGS. 9A and 9B are conceptual diagrams illustrating different views of another example anti- rotation feature 902 of example device 104 of FIGS. 1-4.
  • FIG. 9A illustrates a side view of distal portion 110 of device 104.
  • FIG. 9B illustrates a top-down view of first electrode 112 of device 104 of FIG. 9A.
  • Anti-rotation feature 902 includes a waveform configuration of the helix of first electrode 112.
  • each coil of the helix of first electrode 112 may include undulation creating a varying pitch between adjacent coils.
  • the undulation may create one or more crests 904 and one or more troughs 906 on each coil.
  • a crest 904 of a first coil may be separated from a trough 906 of coil longitudinally adjacent to and distal to the first coil by first distance 908.
  • the undulation may be sinusoidal.
  • Crest 904 of the first coil may be separated from a trough 906 of a coil longitudinally adjacent to and proximal to the first coil by second distance 908.
  • First distance 908 may be smaller than second distance 910 and may represent areas of reduced pitch created by alignment of crests 904 and troughs 906.
  • Second distance 910 may represent areas of increased pitch created by alignment of crests 904 and troughs 906.
  • first value 908 and/or second distance 910 may have a same value across all areas of reduced pitch and all areas of increased pitch on first electrode 112, respectively.
  • one or more areas of reduced pitch and/or one or more areas of increased pitch may have a different distance value than one or more other areas of reduced pitch and/or one or more other areas of increased pitch, respectively.
  • a location with reduced pitch may be located helically between two areas with increased pitches (e.g., with second distance 910).
  • the location with reduced pitch may be a location with a locally minimum pitch (e.g., of one or more coils of first electrode 112 or of all coils of first electrode 112).
  • the location with the locally minimum pitch may be located helically between two areas with locally maximum pitches (e.g., of one or more coils of first electrode 122 or of all coils of first electrode 112).
  • the top-down view (e.g., at a plane parallel to face 503 of distal end 204) of the shape of the helix in the waveform configuration may show an annular shape without any protrusions towards and/or away from longitudinal axis 212.
  • Anti-rotation feature 902 may increase compression of cardiac tissue between consecutive coils of the helix any increase resistance to rotation of device 104.
  • portions of coils of anti-rotation 902 may protrude towards each other along longitudinal axis 212 and create pinch points. The pinch points may increase compression of the cardiac tissue at the pinch points and increase resistance to rotation of device 104 at the pinch points.
  • the user may select the magnitude of the protrusions to adjust a magnitude of compression of the cardiac tissue and/or resistance of anti-rotation feature 902.
  • the shape of the waveforms of the antirotation feature 902 may be user-selected and may depend at least in part on the dimensions of device 104, the dimensions of first electrode 112, and/or the anatomy of heart 102.
  • first electrode 112 may define each of the anti-rotation features discussed above (e.g., shape 602, anti-rotation feature 702, anti-rotation feature 802, anti-rotation feature 902) individually. In other examples, first electrode 112 may define any combination of two or more of the anti-rotation features. For example, first electrode 112 may incorporate multiple diameters, multiple pitches, shape of the helix, and/or a waveform configuration in any combination.
  • FIG. 10 is a flow diagram illustrating an example process for deploying an example device.
  • the technique of FIG. 10 will be described with concurrent reference to device 104 (FIG. 1) although a person having ordinary skill in the art will understand that the technique may be performed in reference to another implantable medical lead or other medical device.
  • a clinician may insert device 104 within a single first chamber of the heart 102, (1002).
  • the clinician may advance first electrode 112 extending distally from housing 202 of device 104 to penetrate through wall tissue of the first chamber and into wall tissue of a second chamber of heart 102 (1004).
  • first electrode 112 may form a tunnel within the wall tissue of heart 102 as first electrode 112 advances through the wall tissue.
  • advancing first electrode 112 includes positioning a distal end of first electrode 112 (e.g., a first electrically active region 216) within a ventricular myocardium 108 of the patient.
  • the clinician may cause device 104 to flexibly maintain contact between second electrode 114 and the wall tissue of the first chamber, without penetrating the wall tissue of the first chamber (1006).
  • flexibly maintaining contact with the wall tissue of the first chamber with second electrode 114 includes contacting atrial endocardium 402 of the patient.
  • flexibly maintaining contact with the wall tissue of the first chamber with second electrode 114 includes deforming second electrode 114 toward elongated housing 202 by the wall tissue of the first chamber as a distance between the distal end of elongated housing 202 and the wall tissue of the first chamber decreases.
  • recess 504 receives at least a portion of second electrode 114 as it is elastically deformed back toward elongated housing 202.
  • a spring bias of second electrode 114 urges second electrode 114 away from housing and into consistent contact with the wall tissue of the first chamber.
  • first electrode 112 While device 104 is implanted within the cardiac tissue, the one or more antirotation features defined by first electrode 112 (e.g., by the helix of the first electrode 112) resist rotation of device 104 due to movement of the cardiac tissue.
  • the one or more antirotation features may prevent movement of first electrode 112 away from wall tissue of the second chamber of heart 102 (e.g., ventricular myocardium 108 of the patient).
  • the one or more anti-rotation feature may also prevent dislodgement of device 104 from within wall tissue of the first chamber of heart 102.
  • the clinician may deliver cardiac pacing from device 104 to the second chamber via first electrode 112 and to the first chamber via second electrode 114 (1008).
  • Device 104 may deliver cardiac pacing to the first chamber and/or the second chamber via first electrode 112, second electrode 114, and/or one or more other electrode of device 104 (e.g., electrode 210).
  • FIG. 11 is a flow diagram illustrating an example process for manufacturing the example anti-rotation feature of example device 104.
  • the manufacturer may form a first electrode 112 (1102).
  • the manufacturer may wrap an elongated body including electrically conductive material around a mandrel (or similar device).
  • the manufacturer may then shape the elongated body into first electrode 112, e.g., into a helix, into a coil with a user-determined shape (e.g., any of shape 602 as discussed above), or the like.
  • the manufacturer may form one or more anti-rotation features on first electrode 112 (1104).
  • the manufacturer may adjust one or more characteristics (e.g., pitch, outer diameter, vertices 601 of shape 602, or the like) of first electrode 112 to form the one or more anti-rotation features on first electrode 112.
  • the manufacturer forms the one or more anti-rotation features while forming first electrode 112.
  • the manufacturer may use the mandrel (e.g., using one or more indentations and/or grooves disposed on the mandrel) to form the one or more anti-rotation features.
  • the material properties of the elongated body may cause increased deformation at vertices 601 compared to sides 603, creating tension within the elongated body.
  • tension within the elongated body may cause a change in shape 602 of the anti-rotation features and/or a change of an inside angle of vertices 601.
  • adjacent coils of first electrode 112 may be out of radial phase with each other, e.g., due to the tension within the elongated body of first electrode 112.
  • the manufacturer may form shapes 602 on first electrode 112 using a mandrel with a cross-section that has a different shape than the intended final shape of shapes 602.
  • the manufacturer may use a triangular mandrel to form rectangular shape 602B on first electrode 112, e.g., due to the tension within the elongated body of first electrode 112.
  • the manufacturer may then attach first electrode 112 to housing 202 of device
  • the manufacturer may attach first electrode 112 to header 502 and then attach header 502 to distal end 204 of housing 202. In some examples, the manufacturer may attach first electrode 112 to face 503 of housing 202. First electrode 112 may be disposed radially inward of second electrode 114. First electrode 112 may be concentric to second electrode 114.
  • FIG. 12 is a flow diagram illustrating another example process for manufacturing the example anti-rotation feature of the example device 104.
  • the manufacturer may form first electrode 112 using a plurality of coiling points (1202).
  • the manufacturer may insert the elongated body include electrically conductive materials into a manufacturing device configured to manufacture first electrode 112.
  • the manufacturing device may include the plurality of coiling points configured to deform and/or deflect the elongated body and shape one or more coils of first electrode 112 (e.g., the one or more coils of the helix of first electrode 112).
  • the manufacturing device may use point-coiling, progressive stamping, and or other know manufacturing techniques to form first electrode 112.
  • the manufacturer may form one or more anti-rotation features on first electrode 112 using indentations in the plurality of coiling points (1204).
  • the plurality of coiling points may include geometry configured to form at least parts of the coils of first electrode 112 into the anti-rotation features described herein (e.g., shape 602, anti-rotation feature 702, anti- rotation feature 802, anti-rotation feature 902, or the like).
  • the manufacturer may use one or more other manufacturing devices, systems, and/or apparatuses to form the anti-rotation features.
  • the manufacturer may then attach first electrode 112 to housing 202 of device 104 (1206). In some examples, the manufacturer may attach first electrode 112 to header 502 and then attach header 502 to distal end 204 of housing 202. In some examples, the manufacturer may attach first electrode 112 to face 503 of housing 202. First electrode 112 may be disposed radially inward of second electrode 114. First electrode 112 may be concentric to second electrode 114.
  • the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit.
  • Computer-readable media may include non-transitory computer-readable media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer).
  • system described herein may not be limited to treatment of a human patient.
  • the system may be implemented in non-human patients, e.g., primates, canines, equines, pigs, and felines. These other animals may undergo clinical or research therapies that may benefit from the subject matter of this disclosure.
  • processors such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry.
  • DSPs digital signal processors
  • ASICs application specific integrated circuits
  • FPGAs field programmable logic arrays
  • processors may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements.
  • Example 1 a fixation device comprising: a first elongated body configured to extend distally from a distal end of an implantable medical device, the first elongated body comprising: a distal end configured to penetrate into tissue of a patient; and a helix having one or more coils, wherein at least one of the one or more coils defines an anti-rotation feature configured to resist rotation of the helix within the tissue; and a second elongated body configured to extend from the distal end of the implantable medical device, wherein the second elongated body is separate from the first elongated body.
  • Example 2 the device of example 1, wherein the first elongated body comprises a first electrode.
  • Example 3 the device of any of examples 1 and 2, wherein the second elongated body comprises a second electrode.
  • Example 4 the device of any of examples 1-3, wherein the second elongated body is configured to flexibly maintain contact with the tissue without penetrating the tissue.
  • Example 5 the device of any of examples 1-4, wherein the second elongated body is configured as a partial helix.
  • Example 6 the device of example 5, wherein the partial helix is wound in a same direction as the helix.
  • Example 7 the device of any of examples 1-6, wherein the anti-rotation feature comprises a shape of the helix relative to a plane orthogonal to a longitudinal axis of the implantable medical device.
  • Example 8 the device of example 7, wherein the shape is equilateral.
  • Example 9 the device of any of examples 7 and 8, wherein the shape comprises a plurality of sides joined at a plurality of vertices.
  • Example 10 the device of example 9, wherein plurality of vertices is configured to improve penetration of the tissue by the distal end of the first elongated body.
  • Example 11 the device of any of examples 7-10, wherein the shape comprises a geometric shape, and wherein the helix defines the geometric shape.
  • Example 12 the device of example 11, wherein the helix is configured as a hexagonal helix.
  • Example 13 the device of example 11, wherein the helix is configured as an octagonal helix.
  • Example 14 the device of example 11, wherein the shape comprises a lobed geometric shape, and wherein the helix defines a plurality of lobes configured to form the lobed geometric shape.
  • Example 15 the device of example 12, wherein one or more of the plurality of lobes comprises an outward-pointing vertex adjacent to at least one inward-pointing vertex.
  • Example 16 the device of example 12, wherein one or more of the plurality of lobes comprises an outward-pointing vertex located between a first inward -pointing vertex adjacent to the outward-pointing vertex and a second inward-pointing vertex adjacent to the outward-pointing vertex.
  • Example 17 the device of any of examples 1-16, wherein the helix comprises a distal portion, a medial portion, and a proximal portion, wherein the distal portion includes the distal end of the first elongated body, wherein the distal portion, the medial portion, and the proximal portion define a distal diameter, a medial diameter, and a proximal diameter, respectively, wherein the anti-rotation feature comprises the medial diameter, and wherein the medial diameter is less than the distal diameter and the proximal diameter.
  • Example 18 the device of example 17, wherein the distal diameter is equal to the proximal diameter.
  • Example 19 the device of any of examples 1-18, wherein the anti-rotation feature comprises a pitch of the one or more coils of the helix at a first portion of the helix.
  • Example 20 the device of example 19, wherein the pitch of the one or more coils of the helix at the first portion is smaller than a pitch of the one or more coils of the helix at a second portion on the helix.
  • Example 21 the device of example 20, wherein the first portion is distal to the second portion.
  • Example 22 the device of any of examples 1-16, wherein the anti-rotation feature comprises undulation of the one or more coils, wherein the undulation creates a varying pitch between adjacent coils.
  • Example 23 the device of any of examples 1-16, wherein the anti-rotation feature comprises undulation of the one or more coils, wherein the undulation creates alternating crests and troughs in the longitudinal direction.
  • Example 24 the device of any of examples 1-16, wherein the anti-rotation feature comprises undulation of the one or more coils, wherein the undulation creates alternating crests and troughs, and longitudinally adjacent crests and troughs are aligned to create at least one location of reduced pitch.
  • Example 25 the device of example 24, wherein the at least one location of reduced pitch is located helically between two locations of larger pitch than the reduced pitch.
  • Example 26 the device of example 24, wherein the at least one location of reduced pitch is located helically between two locations of increased pitch.
  • Example 27 the device of example 24, wherein the at least one location of reduced pitch is a location of locally minimum pitch, which is located helically between two locations of locally maximum pitch.
  • Example 28 the device of example 22, wherein the undulation is sinusoidal.
  • Example 29 the device of any of examples 1-28, wherein the first elongated body and the second elongated body are wound in a same direction.
  • Example 30 the device of any of examples 1-28, wherein the first elongated body and the second elongated body are wound in different directions.
  • Example 31 the device of any of examples 1-30, wherein the first elongated body resides in an inner space defined by the second elongated body and is substantially concentric with the second elongated body.
  • Example 32 the device of any of examples 1-31, wherein the second elongated body is configured to be elastically deformed toward the distal end of the implantable medical device by the tissue as a distance between the distal end and the tissue decreases to maintain contact with the tissue without penetration of the tissue.
  • Example 33 a device comprising: an elongated housing that extends from a proximal end of the housing to a distal end of the housing, the elongated housing configured to be implanted wholly within a first chamber of a heart, the first chamber of the heart having wall tissue; a first electrode extending distally from the distal end of the elongated housing, the first electrode comprising: a distal end of the first electrode configured to penetrate from the first chamber into wall tissue of a second chamber of the heart that is separate from the first chamber; and a first elongated body defining a helix extending to the distal end of the first electrode, the helix having an anti-rotation feature configured to resist rotation of the first electrode within the wall tissue of the second chamber or the wall tissue of the first chamber; a second electrode extending from the distal end of the elongated housing, wherein the second electrode is separate from the first electrode; a second elongated body extending distally from the distal end of the
  • Example 34 the device of example 33, wherein the second electrode is disposed on the second elongated body.
  • Example 35 the device of any of examples 33 and 34, wherein the second elongated body is configured to flexibly maintain contact with the wall tissue of the first chamber without penetration of the wall tissue of the first chamber by the second elongated body.
  • Example 36 the device of any of examples 33-35, wherein the anti-rotation feature is configured to resist rotation of the first electrode due to movement of the wall tissue of the second chamber.
  • Example 37 the device of any of examples 33-36, wherein the distal end of the first electrode is configured to penetrate into a ventricular myocardium of the patient, and wherein the second elongated body is configured to flexibly maintain contact with an atrial endocardium of the patient.
  • Example 38 the device of any of examples 33-37, wherein the second elongated body is configured as a partial helix.
  • Example 39 the device of any of examples 33-38, wherein the anti-rotation feature comprises a shape of the helix relative to a plane orthogonal to a longitudinal axis of the elongated housing.
  • Example 40 the device of example 39, wherein the shape is equilateral.
  • Example 41 the device of any of examples 39 and 40, wherein the shape comprises a plurality of sides joined at a plurality of vertices.
  • Example 42 the device of example 41, wherein the plurality of vertices is configured to improve penetration of the tissue by the distal end of the first elongated body.
  • Example 43 the device of any of examples 39-42, wherein the shape comprises a geometric shape, and wherein the helix defines the geometric shape.
  • Example 44 the device of example 43, wherein the helix is configured as a hexagonal helix.
  • Example 45 the device of example 43, wherein the helix is configured as an octagonal helix.
  • Example 46 the device of example 43, wherein the shape comprises a lobed geometric shape, and wherein the helix defines a plurality of lobes configured to form the lobed geometric shape.
  • Example 47 the device of example 46, wherein one or more of the plurality of lobes comprises an outward-pointing vertex adjacent to at least one inward-pointing vertex.
  • Example 48 the device of example 46, wherein one or more of the plurality of lobes comprises an outward-pointing vertex located between a first inward -pointing vertex adjacent to the outward -pointing vertex and a second inward-pointing vertex adjacent to the outward-pointing vertex.
  • Example 49 the device of any of examples 33-48, wherein the helix comprises a distal portion, a medial portion, and a proximal portion, wherein the distal portion includes the distal end of the first elongated body, wherein the distal portion, the medial portion, and the proximal portion defines a distal diameter, a medial diameter, and a proximal diameter, respectively, wherein the anti-rotation feature comprises the medial diameter, and wherein the medial diameter is less than the distal diameter and the proximal diameter.
  • Example 50 the device of example 49, wherein the distal diameter is equal to the proximal diameter.
  • Example 51 the device of any of examples 33-50, wherein the anti-rotation feature comprises a pitch of the helix at a first portion of the helix.
  • Example 52 the device of example 51, wherein the pitch of the helix at the first portion of the helix is smaller than a pitch of the helix at a second portion of the helix.
  • Example 53 the device of example 52, wherein the first portion is distal to the second portion.
  • Example 54 the device of any of examples 33-48, wherein the anti-rotation feature comprises undulation of the one or more coils, wherein the undulation creates a varying pitch between adjacent coils.
  • Example 55 the device of any of examples 33-48 wherein the anti -rotation feature comprises undulation of the one or more coils, wherein the undulation creates alternating crests and troughs in the longitudinal direction.
  • Example 56 the device of any of examples 33-48, wherein the anti-rotation feature comprises undulation of the one or more coils, wherein the undulation creates alternating crests and troughs, and longitudinally adjacent crests and troughs are aligned to create at least one location of reduced pitch.
  • Example 57 the device of example 56, wherein the at least one location of reduced pitch is located helically between two locations of larger pitch than the reduced pitch.
  • Example 58 the device of example 56, wherein the at least one location of reduced pitch is located helically between two locations of increased pitch.
  • Example 59 the device of example 56, wherein the at least one location of reduced pitch is a location of locally minimum pitch, which is located helically between two locations of locally maximum pitch.
  • Example 60 the device of example 54, wherein the undulation is sinusoidal.
  • Example 61 the device of any of examples 33-60, wherein the first electrode and the second electrode are wound in a same direction.
  • Example 62 the device of any of examples 33-60, wherein the first electrode and the second electrode are wound in different directions.
  • Example 63 the device of any of examples 33-62, wherein the first electrode resides in an inner space defined by the second electrode and is substantially concentric with the second electrode.
  • Example 64 the device of any of examples 33-63, wherein the second elongated body is configured to be elastically deformed towards the distal end of the elongated housing by the wall tissue of the first chamber as a distance between the distal end of the elongated housing and the wall tissue of the first chamber decreases to maintain contact with the wall tissue of the first chamber without penetration of the wall tissue of the first chamber.
  • Example 65 the device of any of examples 33-64, wherein the second elongated body extends from a first end to a second end, the first and second ends attached to the elongated housing.
  • Example 66 the device of any of examples 33-65, wherein the second elongated body extends from a first end attached to the elongated housing to a free second end that is bent back towards the elongated housing.
  • Example 67 the device of any of examples 33-66, wherein a length of the first electrode is within a range from approximately 3 millimeters (mm) to approximately 12 mm.
  • Example 68 the device of any of examples 33-65, further comprising a third electrode extending from the distal end of the elongated housing, wherein the third electrode is substantially similar to the second electrode.
  • Example 69 the device of any of examples 33-68, further comprising at least one steroid eluting element configured to elute a steroid proximate to at least one of the first electrode or the second electrode.
  • Example 70 the device of any of examples 33-69, wherein the device comprises an implantable pacemaker configured to be implanted wholly within the first chamber of the heart.
  • Example 71 a method comprising: delivering cardiac pacing from a device to a heart, wherein the device comprises: an elongated housing extending from a proximal end of the housing to a distal end of the housing, the elongated housing configured to be implanted wholly within a first chamber of the heart, the first chamber of the heart having wall tissue; a first electrode extending distally from the distal end of the elongated housing, the first electrode comprising: a distal end of the first electrode is configured to penetrate into wall tissue of a second chamber of the heart that is separate from the first chamber of the heart; and a first elongated body defining a helix, the helix having an antirotation feature configured to resist rotation of the first electrode within the wall tissue of the second chamber; a second electrode extending from the distal end of the elongated housing, wherein the second electrode is separate from the first electrode; and a second elongated body configured to extend from the distal end of the implant
  • Example 73 the method of any of examples 71 and 72, wherein the second electrode is disposed on the second elongated body.
  • Example 74 the method of any of examples 71-73, wherein the distal end of the first electrode is configured to penetrate into a ventricular myocardium of the patient, and wherein the second elongated body is configured to flexibly maintain contact with an atrial endocardium of the patient.
  • Example 75 the method of any of examples 71-74, wherein the second elongated body is configured as a partial helix.
  • Example 76 the method of any of examples 71-75, wherein the anti-rotation feature comprises a shape of the helix relative to a plane orthogonal to the distal end of the elongated housing.
  • Example 77 the method of example 76, wherein the shape is equilateral.
  • Example 78 the method of any of examples 76 and 77, wherein the shape comprises a plurality of sides joined at a plurality of vertices.
  • Example 79 the method of any of examples 76-78, wherein the plurality of vertices is configured to improve penetration of the tissue by the distal end of the first elongated body.
  • Example 80 the method of any of examples 76-79, wherein the shape comprises a geometric shape, and wherein the helix defines the geometric shape.
  • Example 81 the method of example 80, wherein the helix is configured as a hexagonal helix.
  • Example 82 the method of example 80, wherein the helix is configured as an octagonal helix.
  • Example 83 the method of example 82, wherein the shape comprises a lobed geometric shape, and wherein the helix defines a plurality of lobes configured to form the lobed geometric shape.
  • Example 84 the method of example 83, wherein one or more of the plurality of lobes comprises an outward-pointing vertex adjacent to at least one inward-pointing vertex.
  • Example 85 the method of example 83, wherein one or more of the plurality of lobes comprises an outward-pointing vertex located between a first inward -pointing vertex adjacent to the outward-pointing vertex and a second inward-pointing vertex adjacent to the outward-pointing vertex.
  • Example 86 the method of any of examples 71-85, wherein the helix comprises a distal portion, a medial portion, and a proximal portion, wherein the distal portion includes the distal end of the first elongated body, wherein the distal portion, the medial portion, and the proximal portion defines a distal diameter, a medial diameter, and a proximal diameter, respectively, wherein the anti-rotation feature comprises the medial diameter, and wherein the medial diameter is less than the distal diameter and the proximal diameter.
  • Example 87 the method of example 86, wherein the distal diameter is equal to the proximal diameter.
  • Example 88 the method of any of examples 71-87, wherein the anti-rotation feature comprises a pitch of the helix of a first portion of the helix.
  • Example 89 the method of example 88, wherein the pitch of the helix at the first portion of the helix is smaller than a pitch of the helix at a second portion of the helix.
  • Example 90 the method of example 89, wherein the first portion is distal to the second portion.
  • Example 91 the method of any of examples 71-85, wherein the anti-rotation feature comprises undulation of the one or more coils, wherein the undulation creates a varying pitch between adjacent coils.
  • Example 92 the method of any of examples 71-85, wherein the anti-rotation feature comprises undulation of the one or more coils, wherein the undulation creates alternating crests and troughs in the longitudinal direction.
  • Example 93 the method of example 92, wherein the at least one location of reduced pitch is located helically between two locations of larger pitch than the reduced pitch.
  • Example 94 the method of example 92, wherein the at least one location of reduced pitch is located helically between two locations of increased pitch.
  • Example 95 the method of example 92, wherein the at least one location of reduced pitch is a location of locally minimum pitch, which is located helically between two locations of locally maximum pitch.
  • Example 96 the method of example 91, wherein the undulation is sinusoidal.
  • Example 97 the method of any of examples 71-96, wherein the first elongated body and the second elongated body are wound in the same direction.
  • Example 98 the method of any of examples 71-97, wherein the first elongated body and the second elongated body are wound in different directions.
  • Example 99 the method of any of examples 71-98, wherein the first electrode resides in an inner space defined by the second elongated body and is substantially concentric with the second electrode.
  • Example 100 the method of any of examples 71-99, wherein the second elongated body is configured to be elastically deformed towards the distal end of the elongated housing by the wall tissue of the first chamber as a distance between the distal end of the elongated housing and the wall tissue of the first chamber decreases to maintain contact with the wall tissue of the first chamber without penetration of the wall tissue of the first chamber.
  • Example 101 the method of any of examples 71-100, wherein the second electrode extends from a first end to a second end, the first and second ends attached to the elongated housing.
  • Example 102 the method of any of examples 71-100, wherein the second electrode extends from a first end attached to the elongated housing to a free second end that is bent back towards the elongated housing.
  • Example 103 the method of any of examples 71-102, wherein a length of the first electrode is within a range from approximately 3 millimeters (mm) to approximately 12 mm.
  • Example 104 the method of any of examples 71-103, further comprising a third electrode extending from the distal end of the elongated housing, wherein the third electrode is substantially similar to the second electrode.
  • Example 105 the device of any of examples 71-104, further comprising at least one steroid eluting element configured to elute a steroid proximate to at least one of the first electrode or the second electrode.
  • Example 106 a method comprising: forming a first elongated body into one or more coils of a helix, wherein at least one of the one or more coils defines a anti-rotation feature configured to resist rotation of the helix within tissue of a patient; disposing the helix onto a distal end of an implantable medical device such that the helix extends distally from the distal end; and disposing a second elongated body on to the distal end of the implantable medical device, wherein the second elongated body is separate from the first elongated body, and wherein the second elongated body is configured to flexibly maintain contact with the tissue without penetrating the tissue.
  • Example 107 the method of example 106, wherein the first elongated body comprises a first electrode.
  • Example 108 the method of any of examples 106 and 107, wherein the second elongated body comprises a second electrode.
  • Example 109 the method of any of examples 106-108, wherein the antirotation feature comprises a shape of the helix relative to a plane orthogonal to the distal end of the implantable medical device.
  • Example 110 the method of example 109, wherein the shape is equilateral.
  • Example 111 the method of any of examples 109 and 110, wherein the shape comprises a plurality of sides joined at a plurality of vertices.
  • Example 112 the method of any of examples 109-111, wherein the shape comprises a geometric shape, and wherein the helix defines the geometric shape.
  • Example 113 the method of example 112, wherein the helix is configured as a hexagonal helix.
  • Example 114 the method of example 112, wherein the helix is configured as an octagonal helix.
  • Example 115 the method of example 112, wherein the shape comprises a lobed geometric shape, and wherein the helix defines a plurality of lobes configured to form the lobed geometric shape.
  • Example 116 the method of example 115, wherein one or more of the plurality of lobes comprises an outward-pointing vertex adjacent to at least one inward-pointing vertex.
  • Example 117 the method of claim 115, wherein one or more of the plurality of lobes comprises an outward-pointing vertex located between a first inward -pointing vertex adjacent to the outward-pointing vertex and a second inward-pointing vertex adjacent to the outward-pointing vertex.
  • Example 118 the method of any of claims 106-117, wherein the helix comprises a distal portion, a medial portion, and a proximal portion, wherein the distal portion includes the distal end of the first elongated body, wherein the distal portion, the medial portion, and the proximal portion defines a distal diameter, a medial diameter, and a proximal diameter, respectively, wherein the anti-rotation feature comprises the medial diameter, and wherein the medial diameter is less than the distal diameter and the proximal diameter.
  • Example 119 the method of example 118, wherein the distal diameter is equal to the proximal diameter.
  • Example 120 the method of any of examples 106-119, wherein the antirotation feature comprises a pitch of the one or more coils of the helix at a first portion of the helix.
  • Example 121 the method of example 120, wherein the pitch of the one or more coils of the helix at the first portion is smaller than a pitch of the one or more coils of the helix at a second portion on the helix.
  • Example 122 the method of example 121, wherein the first portion is distal to the second portion.
  • Example 123 the method of any of examples 106-117, wherein the antirotation feature comprises undulation of the one or more coils, wherein the undulation creates a varying pitch between adjacent coils.
  • Example 124 the method of any of examples 106-117, wherein the antirotation feature comprises undulation of the one or more coils, wherein the undulation creates alternating crests and troughs in the longitudinal direction.
  • Example 125 the method of any of examples 106-117, wherein the antirotation feature comprises undulation of the one or more coils, wherein the undulation creates alternating crests and troughs, and longitudinally adjacent crests and troughs are aligned to create at least one location of reduced pitch.
  • Example 126 the device of examples 125, wherein the at least one location of reduced pitch is located helically between two locations of larger pitch than the reduced pitch.
  • Example 127 the device of example 125, wherein the at least one location of reduced pitch is located helically between two locations of increased pitch.
  • Example 128 the device of example 125, wherein the at least one location of reduced pitch is a location of locally minimum pitch, which is located helically between two locations of locally maximum pitch.
  • Example 129 the device of example 123, wherein the undulation is sinusoidal.
  • Example 130 a fixation device comprising: a first elongated body configured to extend distally from a distal end of an implantable medical device, the first elongated body comprising: a distal end configured to penetrate into tissue of a patient; and a helix having one or more coils, wherein at least one of the one or more coils defines an antirotation feature configured to resist rotation of the helix within the tissue, wherein the antirotation feature comprises a lobed geometric shape, and wherein the helix defines a plurality of lobes configured to form the lobed geometric shape.
  • Example 131 the device of example 130, wherein one or more of the lobes comprises an outward-pointing vertex adjacent to at least one inward-pointing vertex.
  • Example 132 the device of example 130, wherein one or more of the lobes comprises an outward-pointing vertex located between a first inward-pointing vertex adjacent to the outward-pointing vertex and a second inward-pointing vertex adjacent to the outward-pointing vertex.
  • Example 133 a fixation device comprising: a first elongated body configured to extend distally from a distal end of an implantable medical device, the first elongated body comprising: a distal end configured to penetrate into tissue of a patient; and a helix having one or more coils, the helix comprising a distal portion, a medial portion, and a proximal portion; and an anti-rotation feature defined by the one or more coils, the antirotation feature configured to resist rotation of the helix within the tissue, wherein the antirotation feature comprises the medial portion having a smaller diameter than the distal portion and the proximal portion.
  • Example 134 a fixation device comprising: a first elongated body configured to extend distally from a distal end of an implantable medical device, the first elongated body comprising: a distal end configured to penetrate into tissue of a patient; and a helix having one or more coils, the helix comprising a distal portion, a medial portion, and a proximal portion; and an anti-rotation feature defined by the one or more coils, the anti- rotation feature configured to resist rotation of the helix within the tissue, wherein the antirotation feature comprises the medial portion having a smaller pitch than the distal portion and the proximal portion.
  • Example 135 a fixation device comprising: a first elongated body configured to extend distally from a distal end of an implantable medical device, the first elongated body comprising: a distal end configured to penetrate into tissue of a patient; and a helix having one or more coils; and an anti-rotation feature defined by the one or more coils, the anti-rotation feature configured to resist rotation of the helix within the tissue, wherein the anti-rotation feature comprises a varying pitch of the helix, the varying pitch resulting from an undulating configuration of the one or more coils of the helix.
  • Example 136 the device of example 135, wherein the anti-rotation feature comprises undulation of the one or more coils, wherein the undulation creates a varying pitch between adjacent coils.
  • Example 137 the device of any of examples 135 and 136, wherein the antirotation feature comprises undulation of the one or more coils, wherein the undulation creates alternating crests and troughs in the longitudinal direction.
  • Example 138 the device of any of examples 135-137, wherein the antirotation feature comprises undulation of the one or more coils, wherein the undulation creates alternating crests and troughs, and longitudinally adjacent crests and troughs are aligned to create at least one location of reduced pitch.
  • Example 139 the device of example 138, wherein the at least one location of reduced pitch is located helically between two locations of larger pitch than the reduced pitch.
  • Example 140 the device of example 138, wherein the at least one location of reduced pitch is located helically between two locations of increased pitch.
  • Example 141 the device of claim 138, wherein the at least one location of reduced pitch is a location of locally minimum pitch, which is located helically between two locations of locally maximum pitch.

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  • Radiology & Medical Imaging (AREA)
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Abstract

Un dispositif de fixation comprend : un premier corps allongé conçu pour s'étendre de manière distale à partir d'une extrémité distale d'un dispositif médical implantable, le premier corps allongé comprenant : une extrémité distale conçue pour pénétrer dans le tissu d'un patient ; et une hélice ayant une ou plusieurs bobines ; et un élément anti-rotation défini par la ou les bobines, l'élément anti-rotation étant configuré pour résister à la rotation de l'hélice à l'intérieur du tissu, l'élément anti-rotation comprenant un pas variable de l'hélice, le pas variable résultant au moins en partie d'une configuration ondulée de la ou des bobines de l'hélice.
PCT/IB2023/057195 2022-07-26 2023-07-13 Dispositif de fixation de dispositif médical à élément anti-rotation Ceased WO2024023622A1 (fr)

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EP23751087.0A EP4561669A1 (fr) 2022-07-26 2023-07-13 Dispositif de fixation de dispositif médical à élément anti-rotation
CN202380052390.4A CN119497640A (zh) 2022-07-26 2023-07-13 具有防旋转特征部的医疗装置固定

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WO2025181603A1 (fr) * 2024-02-29 2025-09-04 Medtronic, Inc. Fixation pour électrode d'un dispositif médical implantable

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US20110112619A1 (en) * 2009-11-12 2011-05-12 Foster Arthur J Helix fixation mechanism
US20170072191A1 (en) * 2015-09-11 2017-03-16 Pacesetter, Inc. Tube-cut helical fixation anchor for electrotherapy device
US20200147365A1 (en) * 2018-11-14 2020-05-14 Medtronic, Inc. Leaded electrical stimulation system
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WO2011028949A1 (fr) * 2009-09-03 2011-03-10 Mayo Foundation For Medical Education And Research Dérivations de stimulation, de détection ou de défibrillateur pour une implantation dans le myocarde
US20110112619A1 (en) * 2009-11-12 2011-05-12 Foster Arthur J Helix fixation mechanism
US20170072191A1 (en) * 2015-09-11 2017-03-16 Pacesetter, Inc. Tube-cut helical fixation anchor for electrotherapy device
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