Implantable medical devices and delivery systems

Abstract

The present disclosure relates to pacing of the cardiac conduction system, and to delivery of an implantable medical device (IMD). A delivery catheter may be configured to deliver the IMD, the delivery catheter including a deployment tube, a handle, a cup, and a sleeve. The deployment tube can define a curve along a portion of a length of the deployment tube, the curve comprising a first shape. The handle can be coupled to the proximal end of the deployment tube and used to control the delivery device. The cup can be coupled to the distal end of the deployment tube and configured to house a leadless implantable medical device. The sleeve can be disposed around the perimeter of the deployment tube, the sleeve configured to move from a first undeployed position to a second deployed position and manipulate the curve from the first shape to a second shape.

Description

IMPLANTABLE MEDICAL DEVICES AND DELIVERY SYSTEMS

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 677,408, filed July 31, 2024, the entire content of which is incorporated herein by reference.

[0002] The present disclosure relates generally to implantable medical devices (IMDs) used to pace the conduction system of the heart, such as the left bundle branch (LBB), and a delivery system to deliver such IMDs to the heart. In particular, the present disclosure relates to delivery devices such as a catheter to a position perpendicular to the ventricular septal wall, for delivery of IMDs, systems, and methods for cardiac therapy.

[0003] IMDs, such as cardiac pacemakers or implantable cardioverter defibrillators, deliver therapeutic stimulation to patients’ hearts thereby improving the lives of millions of patients living with heart conditions. Conventional pacing techniques involve pacing one or more of the four chambers of patient’s heart 12 — left atrium (LA) 33, right atrium (RA) 26, left ventricle (LV) 32 and right ventricle (RV) 28, all of which are shown in FIG. 1. One common conventional therapeutic pacing technique that treats a slow heart rate, referred to as Bradycardia, involves delivering an electrical pulse to a patient’s right ventricular tissue. In response to the electrical pulse, both the right and left ventricles contract. However, the heart beat process may be significantly delayed because the pulse travels from the right ventricle through the left ventricle. The electrical pulse passes through the muscle cells that are referred to as myocytes. Myocyte-to-myocyte conduction may be very slow. Delayed electrical pulses can cause the left ventricle to be unable to maintain synchrony with the right ventricle.

[0004] Over time, the left ventricle can become significantly inefficient at pumping blood to the body. In some patients, heart failure can develop such that the heart is too weak to pump blood to the body. Heart failure may be a devastating diagnosis since, for example, fifty percent of the heart failure patients have a life expectancy of five years. To avoid the potential development of heart failure, some physicians have considered alternative pacing methods that involve the cardiac conduction system. The cardiac conduction system, like a “super highway,” may be described as quickly conducting electrical pulses whereas pacing cardiac muscle tissue may slowly conduct electrical pulses, like “traveling on a dirt road.”

[0005] The cardiac conduction system includes sinoatrial node (SA node) 1, atrial internodal tracts 2, 4, 5 (i.e., anterior intemodal 2, middle internodal 4, and posteriorinternodal 5), atrioventricular node (AV node) 3, His bundle 13 (also known as atrioventricular bundle or bundle of His), and right and left bundle branches 8a, 8b. FIG. 1 also shows the arch of aorta 6 and Bachman’s bundle 7. The SA node, located at the junction of the superior vena cava and right atrium, is considered to be the natural pacemaker of the heart since it continuously and repeatedly emits electrical impulses. The electrical impulse spreads through the muscles of right atrium 26 to left atrium 33 to cause synchronous contraction of the atria. Electrical impulses are also carried through atrial internodal tracts to atrioventricular (AV) node 3 - the sole connection between the atria and the ventricles. Conduction through the AV nodal tissue takes longer than through the atrial tissue, resulting in a delay between atrial contraction and the start of ventricular contraction. The AV delay, which is the delay between atrial contraction and ventricular contraction, allows the atria to empty blood into the ventricles. Then, the valves between the atria and ventricles close before causing ventricular contraction via branches of the bundle of His. His bundle 13 is located in the membranous atrioventricular septum near the annulus of the tricuspid valve. His bundle 13 splits into right and left bundle branches 8a, 8b and are formed of specialized fibers called “Purkinje fibers” 9. Purkinje fibers 9 may be described as rapidly conducting an action potential down the ventricular septum (VS), spreading the depolarization wavefront quickly through the remaining ventricular myocardium, and producing a coordinated contraction of the ventricular muscle mass.

[0006] While cardiac conduction system pacing is increasingly used as an alternative to traditional pacing techniques, cardiac conduction system pacing has not been widely adopted for a variety of reasons. For example, cardiac conduction system pacing electrodes should be positioned within a precise target location (e.g., within about 1 millimeter) of the cardiac conduction system, which may be difficult. Further, motion of the heart during normal function can dislodge or move pacing electrodes over time. It is desirable to develop new methods and systems of delivering IMDs for cardiac conduction system pacing that overcome some of the disadvantages associated with cardiac conduction system pacing.SUMMARY

[0007] The techniques of this disclosure generally relate to systems for pacing the cardiac conductive system, e.g., the LBB, and further relate to delivery systems fordelivering such cardiac conductive system pacing systems. The techniques of this disclosure generally relate to a catheter that guides an implantable medical device or lead for delivery of the device or lead to the correct location in the ventricular septum at or near the LBB and at an orientation to deliver pacing at or near the LBB.

[0008] In some cases, a conduction block can either exist due to disease progression, such as AV block or infra-Hisian block, or appear during the lead implantation procedure that causes bundle injury or otherwise affects bundle conduction. In such cases, conventional His bundle pacing may not work properly. For example, activation can propagate via one bundle branch but not the other one. Thus, this disclosure provides bundle branch pacing by bypassing the block region and algorithms that allow better pacing timing and output to provide a better ventricular synchronization than conventional His bundle pacing.

[0009] It can be difficult to implant a lead close enough to the LBB to effectively pace the LBB, or implanted LBB lead(s) may dislodge over time due to natural movement or due to injury, for example, and left ventricular (LV) septal pacing may occur as a result. This is also true for the RBB pacing shifting into right ventricular (RV) septal pacing. On one hand, for patients whose cardiac conduction systems work normally, septal pacing may be undesirable in some cases. On the other hand, for patients whose cardiac conduction systems do not work normally, septal pacing may be desirable in some cases, such as, for example, when the patient experiences LBB or RBB block that cannot be corrected or bypassed. In other cases for patients whose cardiac conduction systems do not work normally, cardiac conduction system pacing is still desirable, such as, for example, when the LBB or RBB block can be corrected or bypassed. Pacing modes may be chosen based on the individual patient’s needs.

[0010] Additionally, it can be difficult to implant a lead quickly and efficiently without needing to manipulate the catheter to ensure appropriate lead placement. Steerable and manipulatable catheters thus may be more difficult to use and require a higher level of skill by the medical professional using the catheter to implant a medical device. Additionally, it can be difficult to advance a lead out of a catheter without forces acting on the catheter to push it back from the desired placement, resulting in further difficulty in placing the lead correctly. The stiffness and curvilinear structure of a catheter may help offset such difficulties.

[0011] In particular, illustrative devices, systems, and methods are described herein related to a catheter or other delivery device configured to deliver a lead or other secondary device into a patient’s heart. More specifically, the catheter is designed to deliver the lead at or near the LBB for cardiac conduction system pacing. Such cardiac conduction system pacing may include, for example, LBB pacing or left bundle branch area (LBBA) pacing. The catheter design includes a distal portion that is pre-formed and that is curvilinear in a relaxed state. The distal portion facilitates easier, more efficient LBBA placement without the need for manipulation of the catheter to ensure proper placement.

[0012] In one aspect, a delivery device may be configured to deliver an implantable medical device to a patient’s heart from a supracardiac vascular location. The delivery device may include a deployment tube extending from a proximal end to a distal end and defining a length and an outer perimeter measured orthogonal to the length. The deployment tube may further define a curve along a curved portion of the length of the deployment tube, the curve including a first shape. The delivery device may further include a handle coupled to the proximal end of the deployment tube. The handle may be controllable by a user to control the delivery device. The delivery device may further include a cup coupled to the distal end of the deployment tube. The cup may be configured to house a leadless implantable medical device. The delivery device may further include a movable sleeve disposed around the outer perimeter of the deployment tube. The movable sleeve may be configured to move from a first undeployed position to a second deployed position and manipulate the curve from the first shape to a second shape.

[0013] In one aspect, a method of implanting a leadless implantable medical device includes advancing a delivery system housing the leadless implantable medical device from a supracardiac vascular location in a patient to the patient’s right ventricle (RV). The delivery system may include a deployment tube and a movable sleeve disposed around a perimeter of the deployment tube. The method may further include deploying the movable sleeve from a first undeployed position to a second deployed position such that an articulatable length of the deployment tube is decreased. The method may further include deflecting the articulatable length of the deployment tube using a pull wire. The method may further include fixating the leadless implantable medical device to the patient’s RVseptal wall. The method may further include removing the delivery system from the patient.

[0014] In one aspect, a leadless implantable medical device may include first and second electrode surfaces for delivering pacing pulses to, and sensing electrical activity of, a heart of a patient. The leadless implantable medical device may further include a housing containing circuitry operably coupled to the first and second electrode surfaces. The circuitry may be configured to sense electrical activity of the patient’s heart, and initiate delivery of pacing pulses to the patient’s heart. The housing may be sized for implantation within a heart of a patient. The leadless implantable medical device may further include a straight, tissue-penetrating member extending distally from a distal end of the housing. The tissue-penetrating member may include a shaft. The first electrode may be positioned at a distal end of the shaft. The shaft may include a helically wound coil extending distally from the housing along a longitudinal axis of the shaft. A distal end of the coil may be spaced proximally from a distal, tissue-penetrating tip of the tissue-penetrating member. The leadless implantable medical device may further include one or more tissue fixation members located near the distal end of the housing and configured to fixate the housing to cardiac tissue.

[0015] In one aspect, a system includes a leadless implantable medical device including a spear electrode and configured to be implanted in a patient’s right ventricular (RV) septal wall and perform at least one of sensing and pacing of the patient’s left bundle branch (LBB) area using the spear electrode. The system may further include a delivery device including a deployment tube and a sleeve. The delivery device may be configured to orient a distal end of the leadless implantable medical device perpendicular to the patient’s RV septal wall. The delivery device may be further configured to implant the leadless implantable medical device in the patient’s RV septal wall. The spear electrode may define a spear electrode elasticity. The deployment tube may define a deployment tube elasticity. The sleeve may define a sleeve elasticity. The spear electrode elasticity, the deployment tube elasticity, and the sleeve elasticity may each be optimized for enabling LBB area pacing.

[0016] In one aspect, a system includes a delivery catheter housing the device of any of the aspects described herein in a cup having a distal opening. The tissue penetrating member and the one or more tissue fixation members may be pointed distally within thecup toward the distal opening, such that the device can be fixated in cardiac tissue and the first electrode at the tip of the tissue penetrating member can electrically couple to the LBB area of the patient’s heart in response to a distal push force applied to the device.BRIEF DESCRIPTION

[0017] FIG. l is a schematic diagram of a heart of a patient (prior art);

[0018] FIG. 2 is a schematic diagram of a heart of a patient with an implanted LBBA leadless IMD.

[0019] FIG. 3 A is a side view of a delivery catheter that may be included in an interventional medical system, according to some embodiments;

[0020] FIG. 3B an enlarged view of a distal end of the delivery catheter, with a partial cut-away section view, according to some embodiments;

[0021] FIG. 4A is an end view of the delivery catheter, according to some embodiments;

[0022] FIG. 4B is a cross-section view through section line B-B of FIG. 4A, according to some embodiments;

[0023] FIGS. 5A-5B are a side view and a corresponding bottom view of the delivery catheter, upon actuation of a single pull wire thereof, according to some embodiments;

[0024] FIG. 6A is a plan view of a handle of the delivery catheter, according to some embodiments;

[0025] FIG. 6B is a cut-away section showing a portion of an inner assembly of the delivery catheter extending within an outer assembly of the delivery catheter, according to some embodiments;

[0026] FIG. 7 is a perspective view of a tether assembly coupled to an implantable medical device, according to some embodiments;

[0027] FIG. 8A is a perspective view of the tether assembly in relation to the handle of the delivery catheter, according to some embodiments; and

[0028] FIG. 8B is another perspective view of the tether assembly in relation to the handle, according to some embodiments;

[0029] FIG. 9A is a schematic diagram of a delivery catheter (prior art);

[0030] FIG. 9B is a schematic diagram of another delivery catheter, according to some embodiments;

[0031] FIG. 10A is a schematic diagram of another delivery catheter, according to some embodiments;

[0032] FIG. 10B is a schematic diagram of another delivery catheter, according to some embodiments;

[0033] FIG. 10C is a schematic diagram of another delivery catheter, according to some embodiments;

[0034] FIG. 10D is a schematic diagram of another delivery catheter, according to some embodiments;

[0035] FIG. 10E is a schematic diagram of another delivery catheter, according to some embodiments;

[0036] FIG. 1 OF is a schematic diagram of the delivery catheter of FIG. 10E;

[0037] FIG. 10G is a schematic diagram of the delivery catheter of FIGS. 10E-10F;

[0038] FIG. 11 A is a perspective view of an IMD, according to some embodiments;

[0039] FIG. 1 IB is a side view of the IMD of FIG. 11 A;

[0040] FIG. 11C is a partial schematic view of the IMD of FIGS. 11 A-l IB located within a delivery catheter;

[0041] FIG. 1 ID is a partial schematic view of the IMD of FIGS. 11 A-l 1C located within a delivery catheter;

[0042] FIG. 1 IE is a partial view of the IMD of FIG. 1 IB;

[0043] FIG. 12A is a perspective view of an IMD, according to some embodiments;

[0044] FIG. 12B is a perspective view of an IMD, according to some embodiments;

[0045] FIG. 12C is a perspective view of an IMD, according to some embodiments;

[0046] FIG. 12D is a perspective view of an IMD, according to some embodiments;

[0047] FIG. 13A is a schematic diagram of an IMD tip, according to some embodiments;

[0048] FIG. 13B is a schematic diagram of an IMD tip, according to some embodiments;

[0049] FIG. 13C is a schematic diagram of an IMD tip, according to some embodiments;

[0050] FIG. 13D is a schematic diagram of an IMD tip, according to some embodiments;

[0051] FIG. 14A is a schematic diagram of a heart of a patient with a delivery catheter;

[0052] FIG. 14B is a schematic diagram of a heart of a patient with an IMD delivered using the delivery catheter of FIG. 14A; and

[0053] FIG. 15 is a flow diagram showing one illustrative method for implanting an IMD for cardiac conduction system pacing.DETAILED DESCRIPTIONIMD Delivery Devices

[0054] FIG. 2 is a conceptual diagrams illustrating one example delivery system and therapy system that may be used to provide therapy to heart 12 of a patient. Patient ordinarily, but not necessarily, will be a human. Therapy system includes IMD 16, which is leadless, and which may include or be coupled to a programmer. IMD 16 may be, for example, an implantable pacemaker, cardioverter, and / or defibrillator that provides electrical signals to heart 12 via electrodes. Further non-limiting examples of IMD 16 include: a pacemaker with a medical lead, an implantable cardioverter-defibrillator (ICD), an intracardiac device, a leadless pacing device (LPD), a subcutaneous ICD (S-ICD), and a subcutaneous medical device (e.g., nerve stimulator, inserted monitoring device, etc.).

[0055] As used herein, “leadless” refers to a device being free of a lead extending out of patient’s heart 12. In other words, a leadless device may have a lead that does not extend from outside of the patient’s heart to inside of the patient’s heart. Some leadless devices may be introduced through a vein, but once implanted, the devices are free of, or may not include, any transvenous lead and may be configured to provide cardiac therapy without using any transvenous lead. In one or more embodiments, an LPD for bundle pacing does not use a lead to operably connect to an electrode disposed proximate to the septum when a housing of the device is positioned in the atrium. A leadless electrode may be leadlessly coupled to the housing of the medical device without using a lead between the electrode and the housing.

[0056] IMD 16 may sense electrical signals attendant to the depolarization and repolarization of heart 12 via one or more electrodes 111 coupled to or integral with IMD 16. In some examples, IMD 16 provides pacing pulses to heart 12 based on the electrical signals sensed within heart 12. The configurations of electrodes used by IMD 16 forsensing and pacing may be unipolar or bipolar. IMD 16 may also provide defibrillation therapy and / or cardioversion therapy via electrodes 111. IMD 16 may detect arrhythmia of heart 12, such as fibrillation of ventricles 28 and 32, and deliver defibrillation therapy to heart 12 in the form of electrical pulses. In some examples, IMD 16 may be programmed to deliver a progression of therapies, e.g., pulses with increasing energy levels, until a fibrillation of heart 12 is stopped. IMD 16 may detect fibrillation employing one or more fibrillation detection techniques known in the art.

[0057] Electrodes 111 may take the form of ring electrodes, extendable (as illustrated) and / or fixed helix tip electrodes. Electrodes 111 may be fabricated from any suitable electrically conductive material, such as, but not limited to, platinum, platinum alloy or other materials known to be usable in implantable defibrillation electrodes.

[0058] In the example shown in FIG. 14A, discussed further herein, a delivery catheter extends through one or more veins (not shown), the superior vena cava (not shown), and right atrium, and into right ventricle. In some embodiments, delivery catheter may position IMD 16, and any electrodes associated or included with the IMD, within about 1 millimeter of the LBBA.

[0059] One example of IMD 16 can be the MICRA™ Pacing Systems. A description of the MICRA™ Pacing Systems is found in the Medtronic model MICRA™ AV Transcatheter Pacing System manual (2023) and the Medtronic model MICRA™ Transcatheter Pacing System manual (2023), incorporated herein by reference in their entireties. The MICRA™ Pacing Systems include leadless IMDs with one or more electrodes.

[0060] With reference to FIG. 2, such an IMD 16 is illustrated, wherein a hermetically sealed housing, preferably formed from a biocompatible and biostable metal such as titanium, contains a pulse generator, or an electronic controller (not shown), to which at least one electrode is coupled, for example, by a hermetic feedthrough assembly (not shown) like those known to those skilled in the art of IMDs. Housing may be overlaid with an insulative layer, for example, medical grade polyurethane, silicone, or parylene.

[0061] FIG. 14A, as discussed further herein, further illustrates a distal portion of delivery catheter having been maneuvered up through the inferior vena cava IVC and into the right ventricle from the right atrium, according to methods known in the art of interventional cardiology.

[0062] FIG. 3 A is a side view of a delivery catheter 200 that may be included in an interventional medical system, according to some embodiments. Figure 3 A illustrates delivery catheter 200 including a handle 210, and an outer assembly, which is formed by an elongate deployment tube 230 and an outer, stabilizing sheath 270 that surrounds a proximal portion of deployment tube 230, in proximity to handle 210. Figure 3A further illustrates deployment tube 230 including a cup 232, which is sized to contain an implantable medical device, for example, the above-described IMD 16. Cup 232 also defines a distal opening 203 of deployment tube 230, for example, as seen in the cutaway section view of Figure 3B. Figure 3B illustrates delivery catheter 200 further including an elongate inner assembly 220, around which deployment tube 230 extends, wherein inner assembly 220 includes a distal member 222, which is configured to engage device, for example, by abutting an end of IMD 16, and a single pull wire 224, which is anchored adjacent to member 222. Pull wire 224 preferably extends within a lumen of inner assembly 220, for example, as described below, in conjunction with Figure 4B. With reference back to Figure 3A, a first control member 211 of handle 210 is coupled to pull wire 224, and a second control member 212 is coupled to deployment tube 230.

[0063] According to the illustrated embodiment, movement of first control member 211, per arrow A, actuates pull wire 224 to bend inner assembly 220 and deployment tube 230 (described in greater detail below), and movement of second control member 212, per arrow B, moves deployment tube 230, per arrow W, to withdraw, or retract tube 230 relative to stabilizing sheath 270, inner assembly 220, and IMD 16, for example, from a first position, in which IMD 16 and distal member 222 of inner assembly 220 are contained within cup 232 of tube 230 (Figure 3 A), to a second position, at which device has passed out through distal opening 203 (Figure 3B). The end of IMD 16 that is engaged by member 222 may include a tether attachment structure, for example, like a structure 122 illustrated in Figures 1 and 6, according to some embodiments in which the interventional medical system that includes delivery catheter 200 further includes an elongate tether that extends within one or a pair of lumens of inner assembly 220 and out through a proximal port 213 (Figure 3A) of handle 210. An exemplary tether will be described in further detail below. Figure 3B further illustrates implantable medical IMD 16 including at least one tissue fixation member 115, which is mounted to an opposite end of device housing 105, in proximity to the aforementioned one or more electrodes 111,such that upon actuation of pull wire 224 and subsequent retraction of deployment tube 230, tissue fixation member 115 is directed and exposed to secure IMD 16 at a target implant site so that electrode I l l is held in intimate contact with the tissue at the site.

[0064] According to an exemplary embodiment, cup 232 has an inner diameter of approximately 0.275 inches (-0. 7 centimeters (cm)) and an outer diameter of approximately 0.3 in (-0.8 cm). Although Figures 3A-3B illustrate the outer diameter of cup 232 being enlarged from a remainder of deployment tube 230, for example, over a length of approximately 3.5 cm (-1.4 inches), according to alternate embodiments, an outer diameter along a more significant length, up to an entire length of deployment tube 230, may be the same as that of cup 232. A length of deployment tube 230, between handle 210 and distal opening 203 of deployment tube 230, when tube 230 is in the first position (Figure 3 A), may be between approximately 30 cm and approximately 150 cm, for example, to reach the right ventricle from a femoral access site. A diameter of deployment tube 230, between handle 210 and distal opening 203 of deployment tube 230, when tube 230 is in the first position (Figure 3A), may be between approximately 2 French (FR) and 7 FR. In one or more embodiments, about 2 to about 4 FR size deployment tube 230 is employed.

[0065] Figure 3A further illustrates deployment tube 230 including an articulating segment 234 located just proximal to cup 232. Articulating segment 234 may extend over a length of up to approximately 10 cm, preferably approximately 5.8 cm, and is defined by a composite sidewall that is constructed to bend in two directions in response to the aforementioned actuation of pull wire 224.

[0066] Figure 4A is an end view of delivery catheter 200; and Figure 4B is a crosssection view through section line B-B of Figure 4A, according to some embodiments, by which an exemplary construction of the composite sidewall is shown. Figure 4A illustrates the composite sidewall including a relatively soft section 341 and a relatively stiff section 342, which extend alongside one another and along the length of articulating segment 234. Figure 4B illustrates the composite sidewall of articulating segment 234 including a first, inner portion 301, which extends 360 degrees around inner assembly 220, and a second, outer portion 302, which extends approximately 180 degrees around inner layer 301, for example, being bonded thereto, such that inner portion 301, itself, forms relatively soft section 341, and the combination of inner portion 301 and outer portion 302 formsrelatively stiff section 342. According to some embodiments, first portion 301 includes an inner layer, which lines an interior of deployment tube 230 and is surrounded, or reinforced by a metal braid, for example, a polyether block amide, such as PEBAX® 6333, with a stainless steel braid (e.g., 0.0018" x 0.008" x 45 PPI), and an outer layer, which overlays the inner layer, for example, another grade of polyether block amide, such as PEBAX® 5533, wherein second portion 302 may be formed by a another grade of polyether block amide, for example PEBAX® 7233. According to the illustrated embodiment, when the single pull wire 224 is actuated, via control member 211, the composite sidewall causes articulating segment 234 to bend in a first direction, per arrow DI (Figure 3 A), and in a second direction, per arrow D2 (Figure 4A), toward relatively soft section 341, which is more flexible, or provides less resistance to bending than relatively stiff section 342.

[0067] Cup 232 is preferably formed separately from segment 234, for example, from another grade of poly ether block amide, such as PEBAX® 7233, and then thermally bonded to segment 234. According to some preferred embodiments, cup 232 of deployment tube 230 is fitted with a radiopaque marker 30 (Figure 4A), for example, a gold foil, with an adhesive backing, which is sandwiched between layers of the polyether block amide, in proximity to distal opening 203, and distal member 222 of inner assembly 220 is radiopaque, so that the retraction of tube 230, relative to member 222, can be observed via fluoroscopy. As was mentioned above, the outer diameter of cup 232 of deployment tube is shown enlarged from a remainder of deployment tube 230, (e.g., over a length of approximately 3.5 cm), which may be preferred, so that a majority of the length of deployment tube 230 has a smaller outer diameter, which allow for a smaller introducer sheath to provide access for delivery catheter 200 into a patient's venous system. Thus, the aforementioned exemplary construction of marker band 30, from a flexible gold foil, allows for some deformation of cup 232, when passing through the smaller introducer sheath, upon initial insertion of delivery catheter 200 into the patient's venous system.

[0068] With further reference to Figure 3A, deployment tube 230 includes a segment 236 having a pre-formed curvature, which is located just proximal to articulating segment 234, wherein a length of segment 236 may be up to approximately 20 cm. According to the illustrated embodiment, the pre-formed curvature of segment 236 orients cup 232 of deployment tube 230 at an angle of approximately 90 degrees with respect to a length oftube 230 that extends proximally from segment 236 toward handle 210. A radius R about which the pre-formed curvature extends may be between approximately 9 cm and approximately 13 cm. The curvature may be formed in deployment tube 230 prior to the assembly of inner assembly 220 therein, for example, by heat setting methods known in the art. With further reference to Figure 3 A, in conjunction with Figure 3 A, relatively soft section 341 and relatively stiff section 342 of the composite wall of articulating segment 234 meet, or abut one another along a line 3 (dashed, in Figure 4A) that is tangent to an outside of the preformed curvature, and along a similar line on an opposite side of deployment tube 230.

[0069] Segment 236, and the length of deployment tube 230 that extends proximally therefrom, may be any suitable construction known in the art, to achieve a graduated flexibility and the necessary pushability and torque transfer that facilitates the maneuverability of delivery catheter 200 to a target implant site. For example, the aforementioned construction of inner portion 301 of articulating segment 234 may extend proximally along segment 236 and the proximal length to handle 210, wherein varying durometers of polyether block amide are used for the outer layer, to transition the stiffness / flexibility along the length of deployment tube 230.

[0070] Figure 4B further illustrates inner assembly 220 including a multi-lumen tube 320 to which distal member 222 is coupled (Figure 3B), according to some embodiments. Multi-lumen tube 320 may be extruded polyether block amide, polyurethane, or silicone rubber, or a composite thereof, and may include an overlay (not shown), for example, formed of braid reinforced poly ether block amide. According to the illustrated embodiment, multi-lumen tube 320 includes one, relatively large lumen 321, and three, relatively small lumens 322-324, wherein pull wire 224 extends within lumen 324, and lumens 321-323 are in fluid communication with distal opening 203 of deployment tube 230, and with proximal port 213 of handle 210 (Figures 3A-B). According to an exemplary embodiment, pull wire 224 has a diameter of approximately 0.009 inches (-0.23 millimeters (mm)) and is formed from medical grade 304 stainless steel, which is preferably coated with a fluoropolymer such as polytetrafluoroethylene (PTFE). It should be noted that the orientation, relative to sections 341, 342 of articulating segment 234, of pull wire 224, within lumen 324 is not necessarily fixed, so may vary from that illustrated in Figure 4B.

[0071] Lumens 322, 323 of multi-lumen tube 320 are preferably sized to accommodate first and second lengths of an elongate tether 36, for example, being looped and secured to tether attachment structure 122 of IMD 16, when the end of IMD 16 abuts distal member 222 of inner assembly 220, as shown in Figure 3B. Elongate tether 36 may be part of a tether assembly 600, according to some embodiments of the interventional medical system, which will be described below, in conjunction with Figures 7-8B. Although the inclusion of separate lumens 322, 323, to accommodate the first and second lengths of the looped tether are useful in preventing a tangling of the first and second lengths, according to some alternate embodiments, multi-lumen tube 320 need not include lumens 322, 323, and both lengths of the looped tether 36 may extend in lumen 321. In either case, it should be noted that proximal port 213 of handle 210 accommodates passage of tether 36 therethrough, to provide an operator of delivery catheter 200 access to tether 36. Lumen 321 of multi-lumen tube 320 is preferably sized to accommodate a snare (not shown), which may be inserted therein, through proximal port 213, and used to retrieve IMD 16, if necessary, from an implant site, after tether 36 is cut and disengaged from tether attachment structure 122 of IMD 16.

[0072] With reference back to Figure 3 A, handle 210 further includes a flushing subassembly 215. Figure 3 A illustrates flushing subassembly 215 including a connector port 205, for example, to which a saline-filled syringe may be attached, and a flexible tube 25 that defines a flush lumen in fluid communication with lumens 321-323 of multi -lumen tube 320. Flushing of delivery catheter 200, via subassembly 215, is useful to purge air therefrom, and is further described below, in conjunction with Figures 6A-6B.

[0073] Turning now to Figures 5A-5B, the significance of the response of articulating segment 234 of deployment tube 230, to the actuation of the single pull wire 224 will be described. Figures 5A-5B are a side view and a corresponding bottom view of delivery catheter 200, respectively, upon actuation of pull wire 224. Figures 5A-5B illustrate the aforementioned bending of articulating segment 234 in the first and second directions DI, D2, respectively, in response to actuation of the single pull wire 224 via control member 211 (Figure 3A). It should be noted that that the pre-formed curvature of segment 236 can facilitate the navigation of delivery catheter 200 within the heart, for example, once cup 232 has been passed into the RA of the heart, via the IVC, by orienting cup 232 of deployment tube 230 for passage through the tricuspid valve TV and into the rightventricle RV. Then, once cup 232 has been passed into the right ventricle RV, actuation of the single pull wire 224, for example, via control member 211 (Figure 3 A), results in the simultaneous bending of articulating segment 234, in first direction DI (Figure 5A) and second direction D2 (Figure 5B), to direct cup 232 of deployment tube 230 toward a target site that is located along the right ventricular septal wall (RVSW). Then, IMD 16 may be deployed through distal opening 203 of deployment tube 230, by the retraction thereof relative to inner assembly 220, for example, via control member 212 (Figure 3A), as was described above. Thus, the composite sidewall construction of articulating segment 234 allows for a simplified construction of delivery catheter 200 that includes only the single pull wire 224 and corresponding control member 211 for articulation; furthermore, such a construction can make delivery catheter 200 easier to use.

[0074] Figure 6A is a plan view of handle 210 of delivery catheter 200, according to some embodiments, wherein a first portion of an outer surface, or shell 510A of handle 210 is removed to see an arrangement of components within a second portion of the shell 510B. Figure 6A illustrates first control member 211 including a base portion 511 that wraps around a portion of multi-lumen tube 320 of the above-described inner assembly 220, which extends into handle 210, so that a first end of the aforementioned pull wire 224, for example, that extends out from lumen 324 (Figure 4B) through an opening (not shown) in the sidewall of tube 320, may be coupled to first control member 211, for example, by engaging the first end within base portion 511. With reference back to Figure 3 A, control member 211 is movable within a slot 201, which extends through shell 510A, 510B, relative to inner assembly 220 / multi-lumen tube 320, which is fixed in handle 210 by connection to a tether engaging conduit 580 and the aforementioned flexible tube 25 of flushing subassembly 215, which is shown routed within handle 210. Figure 6A further illustrates second control member 212 including a base portion 512, which is coupled to a proximal end of deployment tube 230 within handle 210, and, like first control member 211, second control member 212 is movable in a corresponding slot 202, which may be seen in Figure 3 A, to move deployment tube 230 between the above-described first and second positions. According to some embodiments, a seal member (e.g., a silicone O-ring; not shown), which may be lubricated, for example, with silicone oil, forms a dynamic sealing interface between deployment tube 230 and inner assembly 220 in proximity to first control member 211.

[0075] The aforementioned stabilizing sheath 270 is also shown extending within handle 210, for example, being coupled thereto in proximity to a distal end 214 of handle 210. With further reference to Figure 3 A, sheath 270 extends along a limited proximal length of the outer assembly and may be relatively rigid to facilitate the movement of deployment tube 230, for example, by preventing an operator who is handling delivery catheter 200 from inadvertently applying a force around tube 230 in proximity to handle 210, which force could impede the movement of tube 230 relative to handle 210 and inner assembly 220. Sheath 270 may also provide an enhanced interface between delivery catheter 200 and a valve of an introducer sheath, for example, an interface that provides improved sealing and / or additional radial strength to counteract a compressive force of the valve, which, if the valve is a Tuohy Borst type, can be tightened down around delivery catheter 200 to different degrees depending upon the operator.

[0076] With further reference to Figure 6A, handle 210 includes a receptacle 506 located in proximity to proximal port 213, wherein receptacle 506 is configured to receive a tether holder 660 of a tether assembly 600, which also includes the aforementioned elongate tether 36, and which is illustrated in Figure 7. As was mentioned above, proximal port 213 allows tether 36 to pass therethrough, to exit delivery catheter 200, and Figure 6A further illustrates tether engaging conduit 580 connecting inner assembly 220 to proximal port 213, thereby allowing passage of tether 36 from inner assembly 220 (e.g., lumens 322, 323 of multi-lumen tube 320) to proximal port 213. Conduit 580 may also allow passage of the aforementioned snare therethrough and into inner assembly 220 (e.g., lumen 321 of multi-lumen tube 320), for delivery of the snare out through distal opening 203 (Figures 3A-3B) of delivery catheter 200. Conduit 580 is described in greater detail below.

[0077] Figure 7 is a perspective view of tether assembly 600 coupled to implantable medical IMD 16, according to some embodiments. Figure 7 illustrates a distal end 36-d of tether 36 secured to attachment structure 122 of IMD 16, a proximal end 36-p of tether 36 attached to tether holder 660, and tether 36 formed in a loop, such that a first length 36-1 of tether 36 extends alongside a second length 36-2 of tether 36. With reference back to Figure 4B, first length 36-1 may extend within lumen 322, and second length 36-2, within lumen 323 of multi-lumen tube 320, when IMD 16 is contained in cup 232 of deployment tube 230. Figure 6 further illustrates tether holder 660 including a locking portion 663, forsecuring proximal end 36-p of tether 36, for example, as seen in Figures 8A-8B, and a pin portion 664, for which receptacle 506 of handle 210 is configured. Tether 36 may be formed from a polyester fiber having a fluoropolymer coating, such as PTFE, or any other suitable material, and tether holder 660 may be formed from a plastic, such as polypropylene, for example, by injection molding.

[0078] Locking portion 663 is shown including a pair of apertures 603, each of which extends from a first side 660-1 (FIG. 7) to a second side 660-2 (Figure 8 A) of tether holder 660, and a corresponding pair of plug members 63, wherein each plug member 63 is configured to fit within the corresponding aperture 603, alongside a corresponding length of proximal end 36-p of tether 36, in order to secure proximal end 36-p to tether holder 660. Pin portion 664 is shown including a pair of grooves 604, each groove 604 approximately aligned with a corresponding aperture 603 and configured to receive a corresponding length 36-1, 36-2 of tether 36 in proximity to proximal end 36-p. According to the illustrated embodiment, plug members 63 extend from a hinged flap 631 of locking portion 663, wherein flap 631 may be closed, per arrow S (FIG. 7), to force plug members 63 into apertures 603, and then opened, to remove plug members 63 from apertures 603, when the operator desires to release of tether 36 from holder 660.

[0079] With reference to Figures 8A-8B, which are perspective views of tether assembly 600 in relation to handle 210, it may be appreciated that grooves 604 facilitate a folding of lengths 36-1, 36-2, for example, per arrow F (Figure 8A), in proximity to the secured proximal end 36-p, around tether holder 660, without tangling, when pin portion 664 is inserted into receptacle 506. It may be seen in Figures 7 and 8A, that, according to some preferred embodiments, grooves 604 extend along first and second sides 660-1, 660- 2 of tether holder 660. It should be noted that, according to some alternate embodiments, locking portion 663 of tether holder 660 may only include one aperture 603 and corresponding plug member 63, and, likewise, pin portion 664 may include a single groove 604 approximately aligned with the single aperture 603.

[0080] Figure 8 A illustrates lengths 36-1, 36-2 of tether 36 extending out from proximal port 213 of handle 210, and proximal end 36-p of tether 36 being secured to tether holder 660 prior to folding lengths 36-1, 36-2 around holder 660, per arrow F. It should be understood that distal end 36-d of tether 36 is preferably secured to IMD 16 (Figure 7), then threaded through inner assembly 220 (e.g., lumens 322, 323 of multi-lumen tube 320) just prior to loading IMD 16 into cup 232 of deployment tube 230, through distal opening 203 (Figures 3A-3B), and then proximal end 36-p, which extends out from proximal port 213, is secured to tether holder 660, for example, as was described above.

[0081] Figure 8B illustrates pin portion 664 of tether holder 660, after tether 36 has been secured and folded thereabout, being inserted, per arrow u, into receptacle 506 of handle 210, so that, as the operator uses handle 210 to navigate and articulate of delivery catheter 200, and to subsequently deploy IMD 16, tether 36 is neatly kept out of the way of the operator. Figures 7 and 8A-8B further illustrate tether holder 660 including a knob 668, which can facilitate the handling of tether holder 660, for example, while securing tether 36 thereto, while folding tether 36 thereabout, for inserting tether holder 660 into receptacle 506, and for removing tether holder 660 from receptacle 506.

[0082] With further reference to Figure 8B, in conjunction with Figure 6A, tether engaging conduit 580 includes a valve member 586 integrated therein. According to an exemplary embodiment, valve member 586 is constructed like a stop-cock valve known to those skilled in the art. Figure 6A shows first portion of shell 510A of handle 210 including an aperture 516, which is formed through a recessed surface 518 of portion 510A, and which provides access to valve member 586 so that an operator can move valve member 586 between an open position (Figure 8A) and a closed position (Figure 6A). In the open position, valve member 586 allows fluid communication between proximal port 213 of handle 210 and lumens 321-323 (Figure 4B) of inner assembly 220, and thus, free movement of tether 36 therethrough. When open, valve member 586 also allows passage of the aforementioned snare therethrough and into inner assembly 220, for example, lumen 321 of multi-lumen tube 320. In the closed position, valve member 586 clamps tether 36, and may provide hemostasis for delivery catheter 200, that is, prevent a back flow of bodily fluids through delivery catheter 200 during navigation and device deployment. Tether 36 is preferably clamped while the operator navigates and articulates delivery catheter 200, and deploys IMD 16, after which, the operator moves valve member 586 into the open position to release tether 36 therefrom; then, upon removing tether holder 660 from receptacle 506, the operator may grasp tether holder 660 and tug on IMD 16, via tether 36, to test the fixation thereof at the implant site. If IMD 16 is adequately fixed, and the implant site is satisfactory, the operator leaves valve member 586 in the open positionso that, once proximal end 36-p is released from tether holder 660, one of lengths 36-1, 36-2 may be grasped to release tether 36 from IMD 16, and withdraw tether 36 out from inner assembly 220, through proximal port 213 of delivery catheter 200.

[0083] With further reference to Figure 6A, in conjunction with Figure 3 A, flexible tube 25 of flushing subassembly 215, which defines the flushing lumen thereof, is routed within handle 210 and extends out distal end 214 thereof, alongside sheath 270, where an end of tube 25 is coupled to connector port 205 (Figure 3 A). According to the illustrated embodiment, the location of connector port 205 at distal end 214 of handle 210, which is generally opposite from proximal port 213, by virtue of the routing of tube 25 out distal end 214, can help to facilitate tether management, via tether holder 660 and receptacle 506, and the overall handling of delivery catheter 200, via handle 210. As was mentioned above, the flush lumen defined by tube 25 is connected to inner assembly 220, and the arrow in Figure 6A indicates the flow of a flushing fluid from the flush lumen to lumens of inner assembly 220 (e.g., lumens 321-323 of multi-lumen tube 320, Figure 4B). Figure 6 A further illustrates the flush lumen being connected to tether engaging conduit 580, and, when valve member 586 of conduit 580 is in the closed position, flow of the flushing fluid, from flush lumen, is blocked from flowing out proximal port 213. It should be noted that, according to the illustrated embodiment, the lumens of inner assembly 220 may also be flushed via proximal port 213, when valve member 586 of conduit 580 is in the open position to allow the fluid communication between proximal port 213 and the lumens.

[0084] According to some preferred embodiments, the flush lumen of flushing subassembly 215 is also in fluid communication with the interior of deployment tube 230, for example, an annular space formed between deployment tube 230 and inner assembly 220, along a length of inner assembly 220, for example, via one or more ports formed through a sidewall of multi-lumen tube 320. Figure 6B is a cut-away section showing a portion of inner assembly 220 extending within the outer assembly of delivery catheter 200, just distal to handle 210, according to some embodiments. Figure 6B illustrates ports 35 formed through the sidewall of tube 320, for example, at lumen 321 (Figure 4B), so that lumen 321 is in fluid communication with the interior of deployment tube 230, as indicated by the arrows, to allow flushing between the inner and outer assemblies of delivery catheter 200. Thus, delivery catheter 200 may be completely purged of air via flushing subassembly 215.The Movable Sleeve of the IMD Delivery Device

[0085] As stated previously, an LBBA pacing device may be difficult to implant, however LBBA pacing may advantageously have a low and stable pacing threshold. Traditional LBBA pacing typically paces the LBBA, which may advantageously enable use of simpler devices and systems. In some embodiments, IMD 16 may include one, two, or more electrodes configured for location at or near one or more bundle branches configured to enable bundle branch pacing.

[0086] Disclosed herein are examples of delivery catheters which are configured for implanting a leadless IMD into the RVSW (e.g. for LBBA pacing), along an access path originating from a supracardiac location, such as a jugular vein, including specifically the right internal jugular vein, and passing through the superior vena cava and then through the right atrium and into the right ventricle. To traverse such an access path, the disclosed delivery catheters provide a deployment tube having (in an initial state) a relatively long, flexible distal section with a relatively large-radius distal preformed curvature. This initial configuration allows for safe and simple navigation of the distal portion of the delivery catheter (including its IMD-bearing cup) from the superior vena cava, through the right atrium and into the right ventricle, along the heart’s natural “down and to the left” orientation. Once the distal portion and cup are in the right ventricle, the distal section of the deployment tube (other than a distal-most articulating section) can be made stiffer by advancing a movable sleeve, which surrounds a proximal portion of the deployment tube in the initial state, over the distal section of the deployment tube, thereby stiffening the distal deployment tube, other than the articulating section. This provides for a short, distal articulating section, which upon actuation of a pull wire, bends laterally to form a sharp, small-radius bend of around 90 degrees or less, with a relatively short lateral extension or lateral distance from the longitudinal axis of the deployment tube to the distal end of the cup. With such a bend formed, the delivery catheter may then be used to implant the leadless IMD into the RVSW at a location usable for LBBA pacing. The delivery catheters disclosed herein can be used to deliver and implant any of the leadless IMDs disclosed herein, including the IMDs 1416, 1516, 1616, 1716, 1816, 1916. (For implanting those IMDs which employ a helix for fixation, a rotatable inner assembly may be employed, as is known in the art.)

[0087] FIG. 9A is a schematic diagram of a delivery catheter (prior art), including a handle 710, a cup 732, a segment 736 of a deployment tube 730, and a stabilizing sheath 770. Unless otherwise noted herein, the elements as described with respect to one embodiment are applicable to other embodiments that use different reference numbers (e.g., handles 210, 710, 810, etc.).

[0088] FIG. 9B is a schematic diagram of another delivery catheter 800 including a handle 810, a cup 832, a deployment tube 830 with a segment 836 and an articulating segment 834 as described herein, and a movable sleeve 870. In some embodiments, the delivery catheter 800 can be similar to, and incorporate the components and functions of, the delivery catheter 200, except as further described herein. The deployment tube 830 may extend from a proximal end (near the handle 810) to a distal end (near the cup 832). The deployment tube 830 defines a length between the proximal and distal ends. Such length may be between about 30 cm and about 150 cm, and may advantageously reach the patient’s RV for a majority of the intended patient population. The deployment tube 830 also defines an outer perimeter measured orthogonal to the length.

[0089] The deployment tube 830 further defines a curve along a curved portion of the length of the deployment tube 830, the curve comprising a first shape. The curved portion of the length of the deployment tube 830 may include the segment 836 having a preformed curvature, which is located just proximal to articulating segment 834. A length of segment 836 may be up to approximately 20 cm. According to the illustrated embodiment, the pre-formed curvature of segment 836 orients cup 832 of deployment tube 830 at an angle of approximately 90 degrees with respect to a length of tube 830 that extends proximally from segment 836 toward handle 810. A radius R about which the pre-formed curvature extends may be between approximately 9 cm and approximately 13 cm. The curvature may be formed in deployment tube 830 prior to the assembly of inner assembly therein, for example, by heat setting methods known in the art.

[0090] Segment 836, and the length of deployment tube 830 that extends proximally therefrom, may be any suitable construction known in the art, to achieve a graduated flexibility and the necessary pushability and torque transfer that facilitates the maneuverability of delivery catheter 800 to a target implant site. For example, varying durometers of polyether block amide may be used for the outer layer, to transition the stiffness / flexibility along the length of deployment tube 830.

[0091] The handle 810 may be coupled to the proximal end of the deployment tube 830, and employed to control the delivery catheter 800 and the delivery of a leadless IMD therewith. The cup 832 may be coupled to the distal end of the deployment tube 830, the cup 832 configured to house a leadless IMD, such as any of the leadless IMDs disclosed herein.

[0092] Movable sleeve 870 is disposed around the perimeter of the deployment tube 830. Movable sleeve 870 defines a movable sleeve length that can be between 20 cm and no more than 5 cm shorter than the length of deployment tube 830. Movable sleeve 870 is configured to move from a first undeployed position (FIG. 9B) to a second deployed position along arrow L. The second deployed position is distal to the first undeployed position (i.e., closer to the cup 832). In other words, when the movable sleeve 870 is in the first undeployed position, the movable sleeve 870 is located proximate the handle 810. Conversely, when the movable sleeve 870 is in the second deployed position, the movable sleeve 870 is located proximate the cup 832. In the second deployed position, a distal end of the movable sleeve may be within approximately 5 cm of a proximal end of the cup. The movable sleeve may be configured to translate along the deployment tube 830 by a distance of at least 1 cm and not beyond the distal end of the deployment tube 830.Movement of the movable sleeve 870 toward the second deployed position shortens an articulatable segment of the deployment tube 830 (i.e., the length of the deployment tube 830 that extends beyond a distal end of the movable sleeve 870 is reduced when the movable sleeve 870 is in the second deployed position). The location of the second deployed position is user selectable within a range of movement of the movable sleeve 870.

[0093] An outer diameter of the sleeve 870 may be less than an outer diameter of the cup 832. An outer diameter of the deployment tube 830 may be less than an outer diameter of the cup 832. Such relative outer diameters may advantageously allow the movable sleeve 870 to move between the proximal and distal ends of the deployment tube 830 without moving beyond or past the deployment tube 830. Thus, when the delivery catheter is removed from the patient, the movable sleeve 870 will be removed along with it.

[0094] The delivery catheter 800 may further include a release mechanism 872 which can be positioned at or near the distal end of the handle 810 and is usable to release the movable sleeve 870. Thus, a user can deploy the movable sleeve 870 and allow it to bedeployed by the user. Thus, the release mechanism 872 retains the movable sleeve 870 in the first undeployed position throughout the process of implanting a leadless IMD, until it is time to advance the movable sleeve 870 to or toward the second deployed position. The user then operates the release mechanism 872 to release the movable sleeve 870 for distal movement, and then when ready grasps the proximal end of the movable sleeve and moves it distally to or toward the second deployed position.

[0095] The delivery catheter 800 may further include a fluorosafe marker 833. The fluorosafe marker 833 may be configured to illustrate a location of the movable sleeve when the movable sleeve is disposed within the patient’s body. The fluorosafe marker 833 may be further illustrated to indicate to a user that the distal end of the delivery catheter has emerged or is about to emerge from the distal end of a surrounding introducer sheath or guide catheter within the patient’s body, and that the user should activate fluoroscopic imaging in order to see the advance of the distal portion of the delivery catheter within the patient, and / or take greater care in further distal advance of the delivery catheter.

[0096] As the movable sleeve 870 moves from the first undeployed position to the second deployed position, the length of the articulating segment 834 is shortened (or generally the length of the portion of the deployment tube 830 extending distally beyond the distal end of the movable sleeve 870 is shortened), and the segment 836 (and / or the articulating segment 834 or distal deployment tube 830) is manipulated from the first shape to a second shape. The bend radius R is smaller (and / or falls within a lower range) in the second shape than in the first shape. For example, the radius R about which the preformed curvature extends may be between approximately 1 cm and less than 9 cm in the second shape. When the deployment tube 830 is in the second shape, the bend radius R can be varied, by selective actuation of the first control member 211 and the pull wire 224, within a lower range than in the first shape, with the radius R generally decreasing with increasing actuation of / tension in the pull wire 224. The deflection angle of the distal deployment tube 830 (as measured as the included angle between the longitudinal axis of the cup 832 and the longitudinal axis of the non-curved portion of the deployment tube 830) can also be varied when in the second shape by varying the degree of actuation of the first control member 211 and / or the pull wire 224. With a moderate actuation of the first control member and pull wire, a deflection angle of about 90 degrees can be attained; with full actuation a sharper deflection angle, e.g. of about 45 degrees, can be attained; with noactuation a more obtuse deflection angle, e.g. of about 135 degrees, can be attained. Accordingly, in some embodiments a range of deflection angles from about 45 degrees to about 135 degrees can be attained when in the second shape. Additionally, when in the second shape the lateral extension of the cup 832 (measured as the lateral / orthogonal distance from the distal end of the cup to the longitudinal axis of the non-curved portion of the deployment tube 830) is smaller than when in the first shape. This lateral extension can be varied somewhat when in the second shape with varying degrees of actuation of the first control member 211 and the pull wire 224. In one or more embodiments, the first shape of the curve may define an angle between approximately 90 degrees and approximately 180 degrees. The second shape of the curve may define an angle of approximately 45 degrees and approximately 135 degrees.

[0097] Consequently, the attainment of the second shape of the articulating segment 834 / segment 836 / distal deployment tube 830 enables the attainment of a variety of delivery catheter configurations that are well suited to the final stages of implantation of a leadless IMD into the RVSW, after the cup 832 has reached the right ventricle, and particularly when delivering from a supracardiac location such as the right internal jugular vein. The lateral extension can be sufficiently small to fit within the width of an adult human right ventricle. It should also be noted that the movable sleeve 870 can provide not a single second shape (e.g. corresponding to a fully distal advance of the sleeve), but a variety or range of second shapes, e.g., corresponding to a variety or range of lengths of the articulating segment resulting from varying the position of the distal end of the movable sleeve 870 along the deployment tube 830. (And therefore in such embodiments the moveable sleeve 870 can occupy any of a variety or range of second deployed positions, not just a single second deployed position.) Accordingly, during a delivery / implantation procedure, the user may employ more than one second shape, and vary the second shape one or more times, as needed to suit the anatomy of the patient being treated.

[0098] Advantageously, when the movable sleeve 870 is in the second deployed position, the cup 832 may have a range of motion in response to operation of a pull wire that includes an orientation perpendicular to the right ventricular septal wall (RVSW) of the patient’s heart. Thus, the IMD may be delivered directly to the RVSW and may be successfully implanted to pace the cardiac conduction system. The cup 832 may beoriented at any location on the RVSW. In some embodiments, the cup 832 has a range of motion in response to operation of a pull wire that includes a location between the patient’s His bundle and a point midway between the patient’s His bundle and the patient’s right ventricular (RV) apex. Such a location is an improvement over existing technologies, as it has historically been difficult to reach the upper half of the RVSW using a delivery catheter in order to deliver and implant an IMD.

[0099] FIG. 10A is a schematic diagram of another delivery catheter 900, according to some embodiments. Similar to FIG. 9B, FIG. 10A illustrates a handle 910, a deployment tube 930, a fluorosafe marker 932, and a movable sleeve 970 as described herein. In some embodiments, the delivery catheter 900 can be similar to, and incorporate the components and functions of, the delivery catheter 200 / 800, except as further described herein. In the delivery catheter 900 there is no release mechanism, and the movable sleeve 970 is free to move along the deployment tube 930 between the proximal and distal ends. This may advantageously provide a simple system to manufacture and use, and the movable sleeve 970 may move towards the second deployed position easily as needed.

[0100] FIG. 10B is a schematic diagram of another delivery catheter 1000, according to some embodiments. Similar to FIGS. 9B and 10A, FIG. 10B illustrates a handle 1010, a deployment tube 1030, a fluorosafe marker 1032, and a movable sleeve 1070 as described herein. In some embodiments, the delivery catheter 1000 can be similar to, and incorporate the components and functions of, the delivery catheter 200 / 800 / 900, except as further described herein. FIG. 10B also illustrates a release mechanism 1072, which is a compression or friction fit between the movable sleeve 1070 and the deployment tube 1030. Such a compression or friction fit may advantageously retain the movable sleeve 1070 in the first undeployed position until the friction between the movable sleeve 1070 and the underlying deployment tube 1030 is overcome, e.g., with application of a sufficient force to move the sleeve 1070 distally along the tube 1030.

[0101] FIG. 10C is a schematic diagram of another delivery catheter 1100, according to some embodiments. Similar to FIGS. 9B and 10A, FIG. 10C illustrates a handle 1110, a cup 1132, a deployment tube 1130, and a movable sleeve 1170 as described herein. In some embodiments, the delivery catheter 1100 can be similar to, and incorporate the components and functions of, the delivery catheter 200 / 800 / 900 / 1000, except as further described herein. FIG. 10C also illustrates a release mechanism, which is a valve assembly1172. valve assembly 1172 may be operably couplable to the movable sleeve 1170 and operably couplable to the deployment tube 1130. The valve assembly 1172 may comprise or function similarly to a rotatable hemostatic valve (RHV). When the valve assembly 1172 is sufficiently open or loosened, e.g. by twisting a cover knob of the valve assembly 1172, the movable sleeve 1170 may be to selectively uncoupled from the deployment tube 1130 and thus may be movable relative to the deployment tube 1130, and when the valve assembly 1172 is sufficiently closed or tightened, the movable sleeve 1170 may be selectively coupled to the deployment tube 1130 and thus may not be movable, or may be immovable or fixed, relative to the deployment tube 1130. The valve assembly 1172 may further include a flush port (not shown), which may advantageously allow for flushing through the movable sleeve 1170.

[0102] FIG. 10D is a schematic diagram of another delivery catheter 1200, according to some embodiments. Similar to FIGS. 9B and 10A, FIG. 10D illustrates a handle 1210, a deployment tube 1230, and a movable sleeve 1270 as described herein. In some embodiments, the delivery catheter 1200 can be similar to, and incorporate the components and functions of, the delivery catheter 200 / 800 / 900 / 1000 / 1100, except as further described herein. FIG. 10D also illustrates a release mechanism, which is a removable adhesive member 1272. The removable adhesive member 1272 may be operably coupled to the deployment tube 1230 and the movable sleeve 1270 when the movable sleeve 1270 is in the first undeployed position, such that the movable sleeve 1270 is maintained in the first undeployed position.

[0103] The adhesive member 1272 (e.g., a strip or a wrap) may be removed using the handle 1210. An additional control knob / button / slider may be manipulated by the user to remove the adhesive member 1272 and store it inside the handle 1210. Such storage advantageously and safely removes the adhesive member 1272 from the patient along with the delivery catheter 1200. Alternatively, the adhesive member 1272 may be removed manually when the user is ready to advance the movable sleeve 1270, and discarded. Further alternatively, the adhesive member 1272 may be broken, torn, or otherwise severed at a break point between the movable sleeve 1270 and the deployment tube 1230.

[0104] FIG. 10E is a schematic diagram of another delivery catheter 1300, according to some embodiments. Similar to FIGS. 9B and 10A, FIG. 10E illustrates a handle 1310, a cup 1332, a deployment tube 1330, and a movable sleeve 1370 as described herein. Insome embodiments, the delivery catheter 1300 can be similar to, and incorporate the components and functions of, the delivery catheter 200 / 800 / 900 / 1000 / 1100 / 1200, except as further described herein. FIG. 10E also illustrates a release mechanism, which is a collar 1372. The collar 1372 may be operably couplable to the deployment tube 1330 and to the movable sleeve 1370 and / or to the handle 1310, e.g. via a threaded connection. The collar 1372 may be configured to maintain a location of the movable sleeve 1370 along the deployment tube 1330 when the collar 1372 is coupled to both the deployment tube 1330 and the movable sleeve 1370. The collar may be controllable by the handle 1310 to be coupled and uncoupled at will from one or more of the deployment tube 1330 or the movable sleeve 1370. For example, the collar may be configured to be tightened against or loosened from the deployment tube by rotating a portion of the collar in a first or second direction, as appropriate. Alternatively, the collar may be configured to be tightened against or loosened from the deployment tube via the pull wire (e.g., pull wire 224 as described herein), as appropriate.

[0105] FIGS. 10F-10G are schematic diagrams of the delivery catheter 1300 of FIG. 10E. FIG. 10F illustrates the collar 1372 rolled, folded, everted, or otherwise uncoupled from the deployment tube 1330 so that it is only operatively coupled to the movable sleeve 1370. The movable sleeve 1370 can thus move along the deployment tube 1330 when the collar 1372 is in this condition. FIG. 10G illustrates the collar 1372 unrolled, unfolded, uneverted, or otherwise re-coupled to the deployment tube 1330 so that it is coupled to both the deployment tube 1330 and the movable sleeve 1370 (to the latter, e.g. via frictional engagement between an overlying proximal portion of the collar 1372 and an underlying portion of the deployment tube 1330). The movable sleeve 1370 thus can no longer move along the deployment tube 1330. Accordingly, with the collar 1372 a user can selectively position the movable sleeve 1370 along the deployment tube 1330 and lock it into the selected position, and then unlock it and move it again, etc. A fluorosafe marker 1333 can be disposed on the movable sleeve 1370.IMDs

[0106] FIG. 11 A is a perspective view of a leadless IMD 1416 which is configured for (but not limited to) implantation in the RVSW and for LBB or LBBA pacing from that location, or for implantation and pacing at any other conduction system pacing (CSP) ornon-CSP pacing location. The IMD 1416 includes a distally-projecting and tissue-piercing electrode, such as a spear electrode 1411, which can be positioned in the LBBA and output pacing pulses to the LBB / LBBA for purposes of LBB / LBBA pacing, when the IMD 1416 is implanted in the RVSW. Any of the various delivery catheters 800-1300 disclosed herein can be used to deliver the IMD 1416 and implant it in the RVSW, using any of the various delivery / implant procedures disclosed herein.

[0107] With further reference to FIG. 11 A, the electrode assembly of the IMD 1416 includes the spear electrode 1411, which includes a shaft 1414 extending distally from a distal portion 1401 of IMD 1416 along a longitudinal axis 1402 of the IMD 1416, and a first electrode surface 1418 formed at or near a distal end of the shaft 1414, e.g. at a distal tip of the shaft 1414. The electrode assembly further includes a ring structure, on which a second electrode surface 1420 is formed, e.g. as a ring electrode. The pair of electrode surfaces 1418, 1420 can provide bipolar pacing and sensing at any implant site (such as the LBBA, or other CSP or non-CSP pacing sites).

[0108] According to the illustrated embodiment, pulse generator electronic circuitry and a battery power source of IMD 1416 are contained within a relatively compact, or miniature, hermetically sealed housing or capsule 1425 thereof, for example, that has a length of approximately 2 to 2.5 cm and a diameter of approximately 20 French (6 - 7 millimeters). Husing or capsule 1425 is preferably formed from a biocompatible and biostable metal such as titanium, which is overlaid with an insulative layer, for example, parylene, polyimide, medical grade polyurethane, Polyether ether ketone (PEEK), or silicone. Hermetic feedthrough(s), such as any known to those skilled in the art, couple one or both (or all) electrode surface(s) 1418, 1420 to the pulse generator circuitry contained within capsule 1425, which is configured, according to methods known to those skilled in art, to sense, via the electrode surfaces, either atrial depolarization (i.e. P-waves), for example, or ventricular depolarization (i.e. R-waves), for example, from various implant site(s), and to apply stimulation pulses to the myocardial tissue and / or to the cardiac conduction system for cardiac pacing when necessary.

[0109] Spear electrode 1411 is configured for pacing (e.g., high impedance pacing) from the first electrode surface 1418 thereof; thus, according to an exemplary embodiment, spear electrode 1411 defines a spear length (measured from the distal end of the capsule 1425 to the distal tip of the first electrode surface 1418) from approximately 5-12 mm, or from approximately 4-10 mm. The shaft 1414 of the spear electrode 1411 defines an outer diameter of approximately 2-3 French (0.6 - 1.0 mm), and the gross surface area of the first electrode surface 1418 is between approximately 1 square mm and approximately 4 square mm. The first electrode surface 1418, in this embodiment forming a distal electrode tip of the spear electrode 1411, may be positionable in or proximate a portion of the patient’s LBBA, and is electrically uninsulated to facilitate electrical contact with the LBBA or other target pacing location. The shaft 1414 may be positionable in or proximate a portion of the patient’s ventricular septum, and may be electrically insulated.

[0110] The shaft 1414 may define a shaft length, L, measured from the distal end of the capsule 1425 to the proximal base of the first electrode surface 1418. The shaft length, L, may be at least 5 mm and no more than 9 mm. The shaft 1414 may define a shaft outer diameter, D. The electrode deployment outer diameter, D, may be at least 2 FR and no more than 4 FR. The tissue penetrating member may define a penetrating member length, and wherein the penetrating member length is at least 5 mm and no more than 12 mm. [OHl] The spear electrode 1411 (and / or the shaft 1414) may define a member Young’s Modulus of at least 50 gigapascals (GPa) and no more than 500 GPa. The spear electrode 1411 may define a member Shear Modulus of at least 20 gigapascals (GPa) and no more than 200 GPa. These values may advantageously promote flexibility in the spear electrode 1411 while maintaining the structural integrity of the spear electrode 1411 during the heart motion experienced by the IMD 1416 throughout its service life. Structural integrity of the spear electrode can be compromised if it experiences material fatigue due to cyclic loading resulting from long term repetitive heart motion.

[0112] In some embodiments, the first electrode surface 1418 may possess a high impedance, resultant of the relatively small gross surface area thereof, thereby providing relatively efficient pacing stimulation, for example, to maximize the life of the battery power source of IMD 1416. Spear electrode 1411 may be formed from a platinum iridium wire or a tantalum wire, for example, having an outer diameter of between approximately 0.005 inch (0.13 mm) and approximately .010 inch (0.25 mm); and the first electrode surface 1418 of spear electrode 1411 may be formed by a titanium nitride (TiN) coating that increases the microscopic surface area of the first electrode surface 1418 for an enhanced interface with the tissue in the paced location, for example, at the LBBA or other CSP (or non-CSP) pacing sites. Ring structure (second electrode surface) 1420 maylikewise be formed of either platinum iridium or tantalum and have a TiN coating that forms the second electrode surface, which may have a surface area of approximately 50 mm2, according to some embodiments.

[0113] As illustrated in FIGS. 1 IB and 1 IE, the shaft 1414 of the spear electrode 1411 may include a helically wound first coil 1415 and a second coil 1417 (shown schematically as a single coil for simplicity). The first and second coils 1415, 1417 may be wound in opposite directions such that, when torsion is applied to the shaft 1414, each coil 1415, 1417 produces torque in opposite directions. This may advantageously provide flexibility and bending to the spear electrode 1411, without compromising the strength or integrity of the spear electrode 1411. One or both of the first and second coils 1415, 1417 can define a coil pitch of zero. A zero-pitch coil may advantageously help to impart column strength / pushability to the shaft 1414. In alternative embodiments, one or both of the first and second coils 1415, 1417 can define a coil pitch that is non-zero, which may advantageously help to impart column flexibility to the shaft 1414. An outer diameter of the second helically wound coil may abut an inner diameter of the first helically wound coil.

[0114] The two coils 1415, 1417 may be disposed in a concentrically layered fashion, with one coil layered (as an outer layer) over the other (forming an inner layer). The coils 1415, 1417 can be disposed around a longitudinally extending core member 1421, which can be a solid cylindrical member or a tubular member formed of a polymer such as PEEK or a suitable metal. An outer jacket 1422, which may be made of a polymer such as polyurethane, can be disposed around the coils 1415, 1417. A steroid eluting member 1423, which can be annular in shape, can be disposed proximal of and / or adjacent to the first electrode surface 1418. The shaft 1414 can include the steroid eluting member 1423 disposed between the first helically wound coil 1415, 1417 and the first electrode surface. The steroid eluting member 1423 can be a monolithic controlled release device (MCRD) configured to elute any suitable steroid such as dexamethasone into tissue adjacent the spear electrode and thereby reduce inflammation. The spear electrode 1411 should be able to be implanted proximate the LBBA, and remain proximate the LBBA over time, despite natural motion of heart muscles and the resulting long term cyclic loading imparted to the spear electrode 1411 thereby. Each of the coils 1415, 1417 may be constructed of one or more of suitable metals such as stainless steel, nitinol, or nickel-cobalt alloys such asMP35N, platinum alloys, stainless alloys, DFT wire (a core / sheath dual material wire), etc. Each of the coils 1415, 1417 can include one or more strands of various materials (e.g., 6 strands of platinum alloy and 6 strands of stainless alloy). The number of strands and materials used can provide various conductivity, flexibility, and radiopacity measurement ranges, and can be chosen based on individual patient needs. Varying the diameter of the shaft 1414 may provide further flexibility measurement ranges. For example, the diameter of the shaft 1414 may affect the lateral stiffness of the shaft 1414. The lateral stiffness of the shaft 1414 may thus be optimized to produce a spear electrode 1411 that resists mechanical fatigue over time and that resists movement / travel within the ventricular septum over time, but which also has ideal flexibility to remain proximate the LBBA during normal heart movement.

[0115] In alternative embodiments, the shaft 1414 merely incudes the core member 1421 of solid or tubular PEEK or metal material, without the opposingly-wound coils.

[0116] The IMD also incudes a computing apparatus (not shown) including processing circuitry, the computing apparatus operably coupled to the one or more electrode surfaces 1418, 1420. The computing apparatus may be configured to perform one or more of: sensing electrical activity of the patient’s heart proximate an LBB area, and initiating delivery of pacing to the patient’s heart proximate the LBB area. The IMD 1416 also includes: one or more shape-memory tines 1430 (which represent one example of a tissue fixation member) located proximate the distal end of the housing or capsule 1425. The tines 1430 are configured to operably couple the IMD 1416 to the patient’s right ventricular (RV) septal wall.

[0117] In order to stabilize and maintain this intimate tissue contact of the electrode surface of electrode tip 1418, the electrode assembly of IMD 1416 further includes one or more tissue fixation members 1430. FIGS. 11 A-l IB illustrate each tissue fixation member 1430. Each tissue fixation member 1430 is held in an unfolded or distally-extending state in the delivery catheter, and upon retraction of the cup 832, the tissue fixation members 1430 penetrate into the ventricular septal wall while bending back in the proximal direction (e.g. toward the housing or capsule 1425), anchoring the IMD 1416 to the ventricular septal wall as the spear electrode 1411 penetrates the RVSW tissue to place the first electrode surface 1418 in or proximate the LBBA, or otherwise in electrical contact with the CSP or myocardium, depending on the implant / pacing location. FIGS. 11C-1 IDare each partial schematic views of the IMD 1416 of FIGS. 11 A-l IB located within a cup 1432 of a delivery catheter as described herein, and illustrate the unfolded or distally extending tissue fixation members 1430. Both the tissue fixation members or tines 1430 and the spear electrode 1411 point distally toward the distal opening of the cup 1432, enabling implant of the IMD 1416 (including causing the spear electrode 1411 to penetrate RVSW or other cardiac tissue) by pushing the IMD 1416 distally against the target tissue while retracting the cup from the IMD 1416.

[0118] FIGS. 12A-12D are perspective views of an IMD 1516, according to some embodiments. First, for example, FIG. 12A illustrates IMD 1516 which may be similar in structure and function to the IMD 1416 of FIGS. 11 A-l IE, but includes a surface electrode 1522 disposed on the distal end of the housing, facing distally. The surface electrode 1522 may advantageously provide ventricular myocardial pacing, or atrial myocardial pacing if the IMD is implanted in an atrium instead of a ventricle. The first electrode surface 1518 can be employed to provide LBBA pacing, as disclosed herein, or ventricle-from-atrium pacing (VFA pacing) when the IMD is implanted in the right atrium at an appropriate location, such as the Triangle of Koch, with the spear electrode extending into ventricular tissue.

[0119] In one or more embodiments, the one or more implantable electrodes further includes a surface electrode disposed on the distal end of the leadless implantable medical device and configured to pace myocardial tissue of the heart. FIG. 12B illustrates IMD 1616 which is similar to IMD 1516 of FIG. 12A in structure and function, and also includes a surface electrode 1622. Further, FIG. 12B illustrates a helix electrode 1611 instead of a spear electrode. The helix electrode 1611 includes a helical shaft 1626 and an electrode tip 1628. The helix electrode 1611 may advantageously screw into the myocardial tissue of the ventricular septum, securing the IMD 1616 to the septum (thus, the tissue fixation members are not needed). However, the flexibility of the helix is higher than that of the spear, which may also correlate to less structural integrity. The shape of the electrode should be chosen based on the needs of the patient.

[0120] In one or more embodiments, the one or more implantable electrodes further comprises an LBB helix electrode (or an electrically inactive fixation helix) disposed around the LBB spear electrode. FIG. 12C illustrates IMD 1716 similar in structure and function to the IMDs of FIGS. 12A-12B or FIGS. 11 A-l IE, including a spear electrode1714 / 1718, a surface electrode 1722 (which can optionally be omitted), and a helix tissue fixation member 1726. Such an embodiment may advantageously provide a very securely fixated IMD while also providing a flexible pacing tip with structural integrity.

[0121] FIG. 12D illustrates IMD 1816 similar to FIGS. 12A-12B, including a spear electrode 1814 / 1818, a surface electrode 1822, and a tissue fixation member 1833. Each tissue fixation member 1833 including a tissue engaging portion 1834 that is terminated by a piercing distal tip 1831. Each tissue engaging portion 1834 extends from the distal tip 1831 thereof, along a circular path, which defines a perimeter in which helical structure is located. Tissue engaging portion 1834 of each tissue fixation member 1833 extends along the circular path toward a fixed end, which is coupled to distal portion 1801 of device 1816. According to the illustrated embodiment, the direction along the circular path, in which each tissue engaging portion 1834 extends from the corresponding distal tip 1831, is the same as in which helical structure extends from piercing distal tip thereof, which is counter-clockwise according to FIG. 12D. In alternative embodiments, the direction may be clockwise. Thus, according to those embodiments in which helical structure is fixedly attached to distal portion 1801 of IMD 1816, like tissue fixation members, and when piercing distal tips 1831 are positioned in proximity to a target implant site for engagement with myocardial tissue, IMD 1816 as a whole may be rotated, for example, in the clockwise direction, to screw both helical structure and tissue fixation members into the tissue. Although FIG. 12D illustrates each tissue engaging portion 1834 extending approximately one half of a turn along the circular path, in alternate embodiments each portion 1834 may extend between approximately one quarter of a turn to approximately one full turn around the circular path.

[0122] FIGS. 13A-13D illustrate various embodiments of electrode tip 1918. Each embodiment illustrates a pointed tip, which may advantageously allow an IMD to be moved into position without a lot of friction against the walls of the heart chambers. Further, electrodes 1911 may be positioned as rings or at strategic locations to disperse weight and improve electrode strength. Finally, for example, and as illustrated in FIGS. 13C-13D, the electrode tip 1918 may include a reverse taper 1919, to allow for easier removal and repositioning of the IMD 1916.

[0123] The embodiments of 13A-13C may further include a helix configuration, but are generally envisioned as demonstrating a conductor (i.e. wire) 1910 with additionalslack. A leading element 1918 may serve as support and anchoring to for the untensioned conductor 1910, which may include independent conductive pathways to one or more tissue facing electrodes 1911. The tissue facing electrodes 1911 may be positioned on the leading element 1918 or the conductor 1910. The conductor 1910 may also be adjacent or wrapped as coaxial with a structural element(s) 1912 which provides the stiffness for penetration. In these configurations, the structural element(s) 1912 of the rigid body may be further minimized for acute placement purposes, relying predominantly on the leadless body splines for chronic stability. A separate segment 1919 may allow for acute withdrawal and re-positioning with a more continuous tissue-device transition.

[0124] In one or more embodiments, the spear electrode defines a member Young’s Modulus of at least 50 gigapascals (GPa) and no more than 500 GPa. In one or more embodiments, the spear electrode defines a member Shear Modulus of at least 20 gigapascals (GPa) and no more than 200 GPa. These values may advantageously promote flexibility in the spear electrode while maintaining the structural integrity of the spear electrode during normal heart motion.

[0125] In one or more embodiments, the IMD (e.g., a leadless IMD) is configured to be delivered to the patient’s heart using the delivery devices as described herein.User Control of the IMD

[0126] In some examples, a programmer (not shown) may be a handheld computing device or a computer workstation or a mobile phone, and may be operatively coupled to IMD 16. Programmer may include a user interface that receives input from a user. The user interface may include, for example, a keypad and a display, which may for example, be a cathode ray tube (CRT) display, a liquid crystal display (LCD) or light emitting diode (LED) display. The keypad may take the form of an alphanumeric keypad or a reduced set of keys associated with particular functions. Programmer can additionally or alternatively include a peripheral pointing device, such as a mouse, via which a user may interact with the user interface. In some embodiments, a display of programmer may include a touch screen display, and a user may interact with programmer via the display. For example, method 2000 shown in FIG. 14 may be used to optimize IMD delivery location. Through the graphical user interface on programmer, a user may place the IMD with guided assistance.

[0127] In addition, the user may use the programmer to select pacing criteria to use when determining whether pacing timing needs to be adjusted post-IMD implantation. For example, QRS duration may be used to determine whether pacing timing needs to be adjusted. QRS complex involves a set of waves that occur in quick succession and is referred to as the QRS complex. In some embodiments, the QRS complex is detected using far-field electrical signals. For example, the far-field electrical signals may be sensed in a far-field electrogram (EGM) monitored by IMD 16 and a separate device, such as a subcutaneously implanted device. QRS duration is the time from which the Q wave is detected until the S wave ends. While QRS duration can be employed in any of the methods described herein, other criteria may also be used including R-wave timing, pacing-RV or -LV sensing, and / or VV delay. Any one of these criteria may be selected by, for example, a processor (not shown) or by a user through a GUI on programmer.

[0128] As used herein, the term “far-field” electrical signal refers to the result of measuring cardiac activity using a sensor, or electrode, positioned outside of an area of interest. For example, an ECG signal measured from an electrode positioned outside of the patient’s heart is one example of a far-field electrical signal of the patient’s heart. As another example, a far-field electrical signal representing electrical activity of a chamber of the patient’s heart may be measured from a sensor, or electrode, positioned in an adjacent chamber.

[0129] As used herein, the term “near-field” electrical signal refers to the result of measuring cardiac activity using a sensor, or electrode, positioned near an area of interest. For example, an EGM signal measured from an electrode positioned on the left side of the patient’s ventricular septum is one example of a near-field electrical signal of the patient’s LV.

[0130] R-wave timing is the time in which QRS is detected. Typically, R-wave timing includes using the maximal first derivative of an R-wave upstroke (or the time of the maximal R-wave value). R-wave timing is also used in the device marker channel to indicate the time of the R-wave or the time of ventricular activation.

[0131] Pacing-RV sensing or pacing-LV sensing (e.g., pacing-to-RV sensing or pacing-to-LV sensing) is the time interval from the pacing (or pacing artifact) to the time of RV or LV sensing. For example, if pacing-RV sensing is much longer than pacing-LV sensing, this may indicate that the LV activation is occurring much earlier than RVactivation (so pacing-RV sensing is longer), then RV pacing may be delivered in synchronization with bundle pacing, so RV and LV activation can occur approximately at the same time.

[0132] A user, such as a physician, technician, or other clinician, may interact with programmer to communicate with IMD 16. For example, the user may interact with programmer to retrieve physiological or diagnostic information from IMD 16. A user may also interact with programmer to program IMD 16, e.g., select values for operational parameters of the IMD.

[0133] For example, the user may use programmer to retrieve information from IMD 16 regarding the rhythm of heart 12, trends therein over time, or tachyarrhythmia (tachy) episodes. As another example, the user may use programmer to retrieve information from IMD 16 regarding other sensed physiological parameters of the patient, such as intracardiac or intravascular pressure, activity, posture, respiration, or thoracic impedance. As another example, the user may use programmer to retrieve information from IMD 16 regarding the performance or integrity of IMD 16 or other components of the system, such as a power source of IMD 16.

[0134] The user may use programmer to program a therapy progression, select electrodes used to deliver defibrillation shocks, select waveforms for the defibrillation shock, or select or configure a fibrillation detection algorithm for IMD 16. The user may also use programmer to program aspects of other therapies provided by IMD 16, such as cardioversion or pacing therapies (e.g., bundle pacing therapy, cardiac resynchronization therapy, anti-tachy therapy, etc.). In some examples, the user may activate certain features of IMD 16 by entering a single command via programmer, such as depression of a single key or combination of keys of a keypad or a single point-and-select action with a pointing device.

[0135] IMD 16 and programmer may communicate via wireless communication using any techniques known in the art. Examples of communication techniques may include, for example, low frequency or radiofrequency (RF) telemetry, but other techniques are also contemplated. In some examples, programmer may include a programming head that may be placed proximate to the patient’s body near the IMD 16 implant site in order to improve the quality or security of communication between IMD 16 and programmer.

[0136] One example configuration of IMD 16 may include a processor, memory, stimulation generator (e.g., electrical pulse generator or signal generating circuit), sensing module (e.g., sensing circuit), telemetry module, and power source. One or more components of IMD 16, such as processor, may be contained within a housing of IMD 16 (e.g., within a housing of a pacemaker). Telemetry module, sensing module, or both telemetry module and sensing module may be included in a communication interface. Memory can include computer-readable instructions that, when executed by processor, cause IMD 16 and processor to perform various functions attributed to IMD 16 and processor herein. Memory may include any volatile, non-volatile, magnetic, optical, or electrical media, such as a random-access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), flash memory, or any other digital media.

[0137] Processor 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), or equivalent discrete or integrated logic circuitry. In some examples, processor may include multiple components, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, or one or more FPGAs, as well as other discrete or integrated logic circuitry. The functions attributed to processor herein may be embodied as software, firmware, hardware or any combination thereof. Processor controls stimulation generator to deliver stimulation therapy to heart 12 according to a selected one or more of therapy programs (e.g., optimization of the atrial-His bundle or bundle branch-ventricle delay, VV delay etc.), which may be stored in memory. Specifically, processor may control stimulation generator to deliver electrical pulses with amplitudes, pulse widths, frequency, or electrode polarities specified by the selected one or more therapy programs.

[0138] If IMD 16 is configured to generate and deliver pacing pulses to heart 12, processor may include pacer timing and control module, which may be embodied as hardware, firmware, software, or any combination thereof. The pacer timing and control module may include a dedicated hardware circuit, such as an ASIC, separate from other processor components, such as a microprocessor, or a software module executed by a component of processor, which may be a microprocessor or ASIC. The pacer timing and control module may include programmable counters which control the basic time intervalsassociated with DDD, VVI, DVI, VDD, AAI, DDI, DDDR, VVIR, DVIR, VDDR, AAIR, DDIR and other modes of single and dual chamber pacing. In the aforementioned pacing modes, “D” may indicate dual chamber, “V” may indicate a ventricle, “I” may indicate inhibited pacing (e.g., no pacing), and “A” may indicate an atrium. The first letter in the pacing mode may indicate the chamber that is paced, the second letter may indicate the chamber in which an electrical signal is sensed, and the third letter may indicate the chamber in which the response to sensing is provided.

[0139] Intervals defined by the pacer timing and control module may include atrial and ventricular pacing escape intervals, refractory periods during which sensed P-waves and R- waves are ineffective to restart timing of the escape intervals, and the pulse widths of the pacing pulses. As another example, the pace timing and control module may define a blanking period and provide signals from sensing module to blank one or more channels, e.g., amplifiers, for a period during and after delivery of electrical stimulation to heart 12. The durations of these intervals may be determined by processor in response to stored data in memory. The pacer timing and control module may also determine the amplitude of the cardiac pacing pulses.

[0140] During pacing, escape interval counters within the pacer timing / control module may be reset upon sensing of R- waves and P-waves. Stimulation generator may include pacer output circuits that are coupled, e.g., selectively by a switching module, to any combination of electrodes 111 appropriate for delivery of a bipolar or unipolar pacing pulse to one of the chambers of heart 12. Processor may reset the escape interval counters upon the generation of pacing pulses by stimulation generator, and thereby control the basic timing of cardiac pacing functions, including anti-tachyarrhythmia pacing.

[0141] The value of the count present in the escape interval counters when reset by sensed R- waves and P-waves may be used by processor to measure the durations of R-R intervals, P-P intervals, P-R intervals and R-P intervals, which are measurements that may be stored in memory. Processor may use the count in the interval counters to detect a tachyarrhythmia event, such as ventricular fibrillation event or ventricular tachycardia event. Upon detecting a threshold number of tachyarrhythmia events, processor may identify the presence of a tachyarrhythmia episode, such as a ventricular fibrillation episode, a ventricular tachycardia episode, or a non-sustained tachycardia (NST) episode. Measurements in His-bundle- or bundle-branch-potential to R-wave interval,measurements in atrial to His-bundle- or bundle-branch-potential interval, and EGM morphology and duration can be used for (1) timing the delivery of bundle branch pacing, (2) determining the efficacy of bundle branch pacing, and / or (3) determining the status of activation propagation such as the presence of left or right bundle branch block.

[0142] In some examples, processor may operate as an interrupt driven device, and is responsive to interrupts from pacer timing and control module, where the interrupts may correspond to the occurrences of sensed P-waves and R-waves and the generation of cardiac pacing pulses. Any necessary mathematical calculations to be performed by processor and any updating of the values or intervals controlled by the pacer timing and control module of processor may take place following such interrupts. A portion of memory may be configured as a plurality of recirculating buffers, capable of holding series of measured intervals, which may be analyzed by processor in response to the occurrence of a pace or sense interrupt to determine whether the patient’s heart 12 is presently exhibiting atrial or ventricular tachyarrhythmia.

[0143] In the examples described herein, processor may identify the presence of an atrial or ventricular tachyarrhythmia episode by detecting a series of tachyarrhythmia events (e.g., R-R or P-P intervals having a duration less than or equal to a threshold) of an average rate indicative of tachyarrhythmia or an unbroken series of short R-R or P-P intervals. The thresholds for determining the R-R or P-P interval that indicate a tachyarrhythmia event may be stored within memory of IMD 16. In addition, the number of tachyarrhythmia events that are detected to confirm the presence of a tachyarrhythmia episode may be stored as a number of intervals to detect (NID) threshold value in memory. In some examples, processor may also identify the presence of the tachyarrhythmia episode by detecting a variable coupling interval between the R-waves of the heart signal. For example, if the interval between successive tachyarrhythmia events varies by a particular percentage or the differences between the coupling intervals are higher than a given threshold over a predetermined number of successive cycles, processor may determine that the tachyarrhythmia is present.

[0144] If processor detects an atrial or ventricular tachyarrhythmia based on signals from sensing module, and an anti-tachyarrhythmia pacing regimen is desired, timing intervals for controlling the generation of anti-tachyarrhythmia pacing therapies by stimulation generator may be loaded by processor into the pacer timing and controlmodule to control the operation of the escape interval counters therein and to define refractory periods during which detection of R-waves and P-waves is ineffective to restart the escape interval counters.

[0145] If IMD 16 is configured to generate and deliver defibrillation shocks to heart 12, stimulation generator may include a high voltage charge circuit and a high-voltage output circuit. In the event that generation of a cardioversion or defibrillation shock is required, processor may employ the escape interval counter to control timing of such cardioversion and defibrillation shocks, as well as associated refractory periods. In response to the detection of atrial or ventricular fibrillation or tachyarrhythmia requiring a cardioversion pulse, processor may activate a cardioversion / defibrillation control module, which may, like pacer timing and control module, be a hardware component of processor and / or a firmware or software module executed by one or more hardware components of processor. The cardioversion / defibrillation control module may initiate charging of the high voltage capacitors of the high voltage charge circuit of stimulation generator under control of a high voltage charging control line.

[0146] Processor may monitor the voltage on the high voltage capacitor, e.g., via a voltage charging and potential (VCAP) line. In response to the voltage on the high voltage capacitor reaching a predetermined value set by processor, processor may generate a logic signal that terminates charging. Thereafter, timing of the delivery of the defibrillation or cardioversion pulse by stimulation generator is controlled by the cardioversion / defibrillation control module of processor. Following delivery of the fibrillation or tachycardia therapy, processor may return stimulation generator to a cardiac pacing function and await the next successive interrupt due to pacing or the occurrence of a sensed atrial or ventricular depolarization.

[0147] Stimulation generator may deliver cardioversion or defibrillation shocks with the aid of an output circuit that determines whether a monophasic or biphasic pulse is delivered, and which electrodes are involved in delivery of the cardioversion or defibrillation shocks. Such functionality may be provided by one or more switches or a switching module of stimulation generator. Stimulation generator is configured to generate electrical stimulation (e.g., pulses) to the LBBA.

[0148] Telemetry module includes any suitable hardware, firmware, software or any combination thereof for communicating with another device, such as programmer. Underthe control of processor, telemetry module may receive downlink telemetry from and send uplink telemetry to programmer with the aid of an antenna, which may be internal and / or external. Processor may provide the data to be uplinked to programmer and the control signals for the telemetry circuit within telemetry module, e.g., via an address / data bus. In some examples, telemetry module may provide received data to processor via a multiplexer.

[0149] In some examples, processor may transmit atrial and ventricular heart signals (e.g., electrocardiogram signals) produced by atrial and ventricular sense amplifier circuits within sensing module to programmer. Programmer may interrogate IMD 16 to receive the heart signals. Processor may store heart signals within memory and may retrieve stored heart signals from memory. Processor may also generate and store marker codes indicative of different cardiac episodes detected by sensing module and may transmit the marker codes to programmer.

[0150] The various components of IMD 16 are coupled to power source, which may include a rechargeable or non-rechargeable battery. A non-rechargeable battery may be selected to last for several years, while a rechargeable battery may be inductively charged from an external device, e.g., on a daily or weekly basis.

[0151] During operation, IMD 16 may collect, measure, and store various forms of diagnostic data. In certain cases, IMD 16 may directly analyze collected diagnostic data and generate any corresponding reports or alerts. In some cases, however, IMD 16 may send diagnostic data to programmer and / or an external device (not shown), either wirelessly or via a point and a network, for remote processing and analysis.Methods

[0152] The delivery catheter 800 / 900 / 1000 / 1100 / 1200 / 1300, or any other suitable delivery catheter, can be used to implant the IMD 16 / 1416 / 1516 / 1616 / 1716 / 1816 / 1916, or any other suitable IMD, as follows, and as illustrated in FIGS. 14A-14B. For the sake of brevity, components of the delivery catheter 200 which are incorporated in at least some embodiments of the delivery catheter 800-1300 have not been described specifically in the disclosure of the delivery catheter 800-1300. Such components will be referred to with the reference numerals that are employed in the discussion of the delivery catheter 200 herein.The use of such reference numerals should not be understood to limit this discussion to the delivery catheter 200.

[0153] Using an appropriate vascular access technique, a guide catheter and / or introducer sheath can be inserted into the right internal jugular vein in the neck and advanced toward the torso, until the tip of the guide catheter or sheath is positioned in the superior vena cava, above the right atrium. The distal portion of the delivery catheter 800- 1300, with the movable sleeve 870-1370 in the first undeployed position and the deployment tube 830-1330 in the un-actuated / un-deflected condition (e.g., with the first control member 211 (not shown) and pull wire 224 (not shown) in the un-actuated / un- deflected condition or position) is then inserted into the guide catheter and / or sheath, and then advanced into and through the superior vena cava, right atrium and tricuspid valve, and into the right ventricle. This maneuver positions the cup 232-832 in the right ventricle, and the procedure entails further manipulating the delivery catheter 800-1300 to orient the cup within the right ventricle and position it against the RVSW for implanting the IMD 16-1916 in the RVSW, as illustrated in FIG. 14A. This is done by advancing the movable sleeve 870-1370 distally along the deployment tube 830-1330 from the first undeployed position to the second deployed position. This has the effect of positioning the distal end of the movable sleeve 870-1370 significantly closer to the cup 232-832 and thereby significantly shortening the length of the portion of the deployment tube 830-1330 that extends distally beyond the distal end of the movable sleeve 870-1370 to the cup 232-832 (e.g. the articulating segment 234-834). Next, the first control member 211 (not shown) is actuated by moving it in the proximal direction in the handle 210 (not shown), thereby applying a proximal tension in the pull wire 224 (not shown) and causing a bending or deflection of the articulating segment 234-834 (see FIG. 14A). Because the articulating segment 234-834 has been significantly shortened, it can form a bend (in response to the tension in the pull wire) with a much smaller radius than is possible with the movable sleeve 870-1370 in the first undeployed position. Additionally, in the bend thus formed there is a much smaller lateral extension of the deployment tube 830-1330 and cup 232- 832 away from the longitudinal axis of the deployment tube 830-1330. This enables orientation of distal end of the cup against the RVSW, even in the relatively small confines of the right ventricle. By applying an appropriate amount of tension in the pull wire 224(not shown) via the first control member 211 (not shown), the user can select the (included) angle of the bend in the deployment tube 830-1330.

[0154] The bend angle can be about 90 degrees, or between about 45 degrees and about 135 degrees. Once the bend has been formed in the deployment tube 830-1330, the user can rotate the delivery catheter counter-clockwise, generally about the longitudinal axis of the deployment tube 830-1330, if needed, and position the distal end of the cup 232-832 against the RVSW, as illustrated in FIG. 14A. The user can then confirm the correct positioning and orientation of the cup against the RVSW via appropriate techniques (e.g., fluoroscopy and / or RVSW electrical signal detection via electrode(s)), and upon confirmation of correct positioning and orientation, implant the IMD 16-1916 by pressing the distal end of the cup 232-832 against the RVSW and actuating the second control member 212 (not shown), thereby retracting the cup, releasing the tines and allowing them to penetrate the RVSW tissue and fixate the IMD to the RVSW, as illustrated in FIG. 14B. Pressing the distal end of the cup 232-832 against the RVSW may involve bracing or bowing a portion of the deployment tube 230-1330 against right side wall of the superior vena cava, right atrium and / or right ventricle. Once implanted, the IMD 16-1916 may position the electrode 111-1911 proximate the LBB, with the device housing 105 / 805 positioned in the right ventricle. Fixating the IMD to the patient’s RVSW can include fixating it at a location between the patient’s His bundle and a point midway between the patient’s His bundle and the patient’s RV apex.

[0155] During the delivery / implantation procedure, the user may employ more than one second shape (and more than one second deployed position of the movable sleeve 870-1370), and vary the second shape and second deployed position one or more times, as needed to suit the anatomy of the patient being treated. The user may do so after observing the relevant anatomy, e.g. via fluoroscopy, and the condition / configuration / position of the delivery catheter 800-1300 therein, and then vary the second shape and / or second deployed position. In other words, during the delivery / implantation procedure, the user may adjust the length of the articulating segment 834 one or more times.

[0156] FIG. 15 is a flow diagram showing one illustrative method for implanting a leadless IMD for cardiac conduction system pacing as described herein. The method 2000 includes: (2001) advancing a delivery system (e.g., delivery catheter 800) housing a leadless implantable medical device from supracardiac vascular location in a patient to thepatient’s right ventricle (RV), the delivery system including a deployment tube and a movable sleeve disposed around a perimeter of the deployment tube as described herein. The method further includes (2002) deploying the movable sleeve 870 from a first undeployed position to a second deployed position such that an articulatable length of the deployment tube 830 is decreased, as described herein. The method 2000 may further including moving the movable sleeve 870 to another second deployed position from the initial second deployed position and thereby re-adjusting the articulatable length of the deployment tube 830.

[0157] The method further includes (2004) deflecting the articulatable length of the deployment tube 830 using a pull wire, as described herein (see FIG. 14A). Deflecting the articulatable length of the deployment tube 830 may include orienting a cup 832 housing the IMD perpendicular to the patient's RVSW. Deflecting the articulatable length of the deployment tube 830 may orient a cup 832 housing the IMD generally perpendicular to the movable sleeve 870 while positioned within the RV of the patient. Deflecting the articulatable length of the deployment tube 830 may orient a cup 832 housing the IMD at an included angle of less than 90 degrees relative to the movable sleeve 870 while positioned within the RV of the patient.

[0158] The method 2000 may further include (2006) fixating the leadless implantable medical device to the patient’s RV septal wall, as described herein. Fixating the leadless implantable medical device to the patient’s RV septal wall can include fixating it at a location between the patient’s His bundle and a point midway between the patient’s His bundle and the patient’s RV apex. The method further includes (2008) removing the delivery system from the patient (see FIG. 14B).

[0159] The method 2000 may further include facilitating LBB area pacing via fixating the IMD to the patient’s RV septal wall. The method 2000 may further include testing an anchor strength of the leadless implantable medical device before removing the delivery system from the patient. The method 2000 may further include testing LBB A electrical sensing and pacing capabilities of the leadless implantable medical device before removing the delivery system from the patient. The method 2000 may further include continuously monitoring the location of a fluorosafe marker of the sleeve as described herein. The method 2000 may further include controlling a collar as described herein. The method 2000 may further include removing an adhesive strip or wrap from one or more ofthe deployment tube and the movable sleeve as described herein. The method 2000 may further include opening a valve assembly as described herein.

[0160] The method 2000 may further include accessing a patient’s jugular vein at an insertion location. The method 2000 may further include advancing the delivery system through the insertion location toward the patient’s right ventricle.Systems

[0161] In one embodiment, a system includes a leadless IMD comprising a spear electrode as described herein. The IMD may be configured to be implanted in a patient’s right ventricular (RV) septal wall and perform at least one of sensing and pacing of the patient’s left bundle branch (LBB) area using the spear electrode, as described herein. The system may further include a delivery device (e.g., a delivery catheter as described herein) including a deployment tube and a sleeve. The delivery device may be configured to orient a distal end of the leadless IMD perpendicular to the patient’s RV septal wall at a location between the patient’s His bundle and a point midway between the patient’s His bundle and the patient’s RV apex, as described herein. The delivery device may also be configured to implant the leadless IMD in the patient’s RV septal wall at the location. The spear electrode may define a spear electrode elasticity, the deployment tube may define a deployment tube elasticity, and the sleeve may define a sleeve elasticity. Further, the spear electrode elasticity, the deployment tube elasticity, and the sleeve elasticity may each be optimized for LBBA pacing. When the spear electrode elasticity, the deployment tube elasticity, and the sleeve elasticity are each optimized for LBBA pacing, the leadless IMD resists mechanical fatigue. Such resistance to fatigue may advantageously secure the IMD to the implant location and resist deformation and movement of the IMD over time.ILLUSTRATIVE EMBODIMENTS

[0162] While the present disclosure is not so limited, an appreciation of various aspects of the disclosure will be gained through a discussion of the specific illustrative embodiments provided below, which provide alloys with superior mechanical and corrosion properties. Various modifications of the illustrative embodiments, as well as additional embodiments of the disclosure, will become apparent herein.

[0163] Embodiment l is a delivery device configured to deliver an implantable medical device to a patient’s heart from a supracardiac vascular location, the delivery device comprising: a deployment tube extending from a proximal end to a distal end and defining a length and an outer perimeter measured orthogonal to the length, the deployment tube further defining a curve along a curved portion of the length of the deployment tube, the curve comprising a first shape; a handle coupled to the proximal end of the deployment tube, the handle controllable by a user to control the delivery device; a cup coupled to the distal end of the deployment tube, the cup configured to house a leadless implantable medical device; and a movable sleeve disposed around the outer perimeter of the deployment tube, the movable sleeve configured to move from a first undeployed position to a second deployed position and manipulate the curve from the first shape to a second shape.

[0164] Embodiment 2 is the delivery device of Embodiment 1, wherein a radius of curvature of the curve is smaller in the second shape than in the first shape.

[0165] Embodiment 3 is the delivery device of Embodiment 1 or Embodiment 2, wherein a lateral extension dimension measured from a distal end of the cup to a longitudinal axis of a proximal portion of the deployment tube is smaller in the second shape than in the first shape.

[0166] Embodiment 4 is the delivery device of Embodiment 1 or Embodiment 2, wherein an included angle of the cup relative to a proximal portion of the deployment tube is adjustable via a pull wire.

[0167] Embodiment 5 is the delivery device of Embodiment 4, wherein the included angle of the cup is adjustable to 45 degrees or more.

[0168] Embodiment 6 is the delivery device of Embodiment 4, wherein the included angle of the cup is adjustable to about 90 degrees.

[0169] Embodiment 7 is the delivery device of Embodiment 3, wherein the lateral extension dimension is sufficiently small to fit within the width of an adult human right ventricle.

[0170] Embodiment 8 is the delivery device of any of Embodiments 1-7, wherein the second deployed position is distal of the first undeployed position.

[0171] Embodiment 9 is the delivery device of any of Embodiments 1-8, wherein, in the second deployed position, a distal end of the movable sleeve is within 5 cm of a proximal end of the cup.

[0172] Embodiment 10 is the delivery device of any of Embodiments 1-9, wherein movement of the movable sleeve toward the second deployed position shortens an articulatable segment of the deployment tube.

[0173] Embodiment 11 is the delivery device of any of Embodiments 1-10, wherein the location of the second deployed position is user selectable within a range of movement of the movable sleeve.

[0174] Embodiment 12 is the delivery device of any of Embodiments 1-11, wherein, when the movable sleeve is in the first undeployed position, the movable sleeve is located proximate the handle.

[0175] Embodiment 13 is the delivery device of any of Embodiments 1-12, wherein, when the movable sleeve is in the second deployed position, the movable sleeve is located proximate the cup.

[0176] Embodiment 14 is the delivery device of any of Embodiments 1-13, wherein, when the movable sleeve is in the second deployed position, the cup has a range of motion in response to operation of a pull wire that includes an orientation perpendicular to a right ventricular (RV) septal wall of the patient’s heart.

[0177] Embodiment 15 is the delivery device of any of Embodiments 1-14, wherein, when the movable sleeve is in the second deployed position, the cup has a range of motion in response to operation of a pull wire that includes a location between the patient’s His bundle and a point midway between the patient’s His bundle and the patient’s right ventricular (RV) apex.

[0178] Embodiment 16 is the delivery device of any of Embodiments 1-15, wherein the length of the deployment tube is at least 75 centimeters (cm) and no more than 150 cm.

[0179] Embodiment 17 is the delivery device of any of Embodiments 1-16, wherein the movable sleeve defines a movable sleeve length, and wherein the movable sleeve length is at least 5 centimeters (cm) and no more than 50 cm.

[0180] Embodiment 18 is the delivery device of any of Embodiments 1-17, further comprising a collar operably couplable to the deployment tube and the movable sleeve andconfigured to maintain a location of the movable sleeve along the deployment tube when the collar is coupled to both the deployment tube and the movable sleeve.

[0181] Embodiment 19 is the delivery device of Embodiment 18, wherein the collar is controllable by the handle to couple and uncouple from one or more of the deployment tube and the movable sleeve.

[0182] Embodiment 20 is the delivery device of Embodiment 1, further comprising a removable adhesive member operably coupled to the deployment tube and the movable sleeve when the movable sleeve is in the first undeployed position such that the movable sleeve is maintained in the first undeployed position.

[0183] Embodiment 21 is the delivery device of Embodiment 1, further comprising a rotatable hemostatic valve assembly operably coupled to the movable sleeve and operably couplable to the deployment tube, the rotatable hemostatic valve assembly controllable to selectively couple the movable sleeve to the deployment tube.

[0184] Embodiment 22 is the delivery device of any of Embodiments 1-21, wherein an inner diameter of the sleeve is less than an outer diameter of the cup.

[0185] Embodiment 22 is the delivery device of any of Embodiments 1-22, wherein an outer diameter of the deployment tube is less than an outer diameter of the cup.

[0186] Embodiment 24 is a method of implanting a leadless implantable medical device, the method comprising: advancing a delivery system housing the leadless implantable medical device from a supracardiac vascular location in a patient to the patient’s right ventricle (RV), the delivery system comprising a deployment tube and a movable sleeve disposed around a perimeter of the deployment tube; deploying the movable sleeve from a first undeployed position to a second deployed position such that an articulatable length of the deployment tube is decreased; deflecting the articulatable length of the deployment tube using a pull wire; fixating the leadless implantable medical device to the patient’s RV septal wall; and removing the delivery system from the patient.

[0187] Embodiment 25 is the method of Embodiment 24, wherein fixating the leadless implantable medical device to the patient’s RV septal wall comprises fixating it at a location between the patient’s His bundle and a point midway between the patient’s His bundle and the patient’s RV apex.

[0188] Embodiment 26 is the method of Embodiment 24 or Embodiment 25, further comprising testing an anchor strength of the leadless implantable medical device before removing the delivery system from the patient.

[0189] Embodiment 27 is the method of any of Embodiments 24-26, further comprising testing left bundle branch (LBB) area electrical sensing or pacing capabilities of the leadless implantable medical device before removing the delivery system from the patient.

[0190] Embodiment 28 is the method of any of Embodiments 24-26, further comprising facilitating LBB area pacing via fixating the leadless implantable medical device to the patient’s RV septal wall.

[0191] Embodiment 29 is the method of any of Embodiments 24-28, wherein deflecting the articulatable length of the deployment tube comprises orienting a cup housing the implantable medical device perpendicular to the patient's RV septal wall.

[0192] Embodiment 30 is the method of any of Embodiments 24-28, wherein deflecting the articulatable length of the deployment tube orients a cup housing the leadless implantable medical device generally perpendicular to the movable sleeve while positioned within the RV of the patient.

[0193] Embodiment 31 is the method of any of Embodiments 24-28, wherein deflecting the articulatable length of the deployment tube orients a cup housing the leadless implantable medical device at an included angle of less than 90 degrees relative to the movable sleeve while positioned within the RV of the patient.

[0194] Embodiment 32 is the method of any of Embodiments 24-31, the delivery system further comprising: a handle coupled to the deployment tube; and a cup coupled to the deployment tube, the cup configured to house the leadless implantable medical device; wherein the deployment tube of the delivery system extends from a proximal end to a distal end, and wherein the handle is coupled to the deployment tube proximate the proximal end of the deployment tube and the cup is coupled to the deployment tube proximate the distal end of the deployment tube; and wherein an inner diameter of the movable sleeve is smaller than an outer diameter of the cup.

[0195] Embodiment 33 is the method of any of Embodiments 24-32, wherein the movable sleeve defines a movable sleeve length, and wherein the movable sleeve length isat least 20 centimeters (cm) and no more than 5 cm shorter than the length of the deployment tube.

[0196] Embodiment 34 is the method of any of Embodiments 24-33, further comprising moving the movable sleeve to another second deployed position from the initial second deployed position and thereby re-adjusting the articulatable length of the deployment tube,

[0197] Embodiment 35 is the method of any of Embodiments 24-34, further comprising controlling a collar couplable to the deployment tube and the movable sleeve, wherein uncoupling the collar from the deployment tube such that the collar is only coupled to the movable sleeve allows manipulation of the movable sleeve from the first undeployed position to the second deployed position.

[0198] Embodiment 36 is the method of Embodiment 35, wherein the collar is controllable using a handle of the delivery system to couple and uncouple it from one or more of the deployment tube and the movable sleeve.

[0199] Embodiment 37 is the method of any of Embodiments 24-34, further comprising removing an adhesive member from one or more of the deployment tube and the movable sleeve such that the movable sleeve is freed for manipulation from the first undeployed position to the second deployed position.

[0200] Embodiment 38 is the method of any of Embodiments 24-34, further comprising opening a rotatable hemostatic valve operably coupled to the movable sleeve and operably couplable to the deployment tube.

[0201] Embodiment 39 is the method of Embodiment 38, wherein, when the rotatable hemostatic valve is open, the movable sleeve is movable relative to the deployment tube, and when the rotatable hemostatic valve is closed, the movable sleeve is immovable relative to the deployment tube.

[0202] Embodiment 40 is the method of any of Embodiments 24-39, further comprising: accessing a patient’s jugular vein at an insertion location; and advancing the delivery system through the insertion location toward the patient's right ventricle (RV).

[0203] Embodiment 41 is a leadless implantable medical device comprising: first and second electrode surfaces for delivering pacing pulses to, and sensing electrical activity of, a heart of a patient; a housing containing circuitry operably coupled to the first and second electrode surfaces, wherein the circuitry is configured to sense electrical activity of thepatient’s heart, and initiate delivery of pacing pulses to the patient’s heart, wherein the housing is sized for implantation within a heart of a patient; a straight, tissue-penetrating member extending distally from a distal end of the housing, the tissue-penetrating member comprising a shaft, wherein the first electrode is positioned at a distal end of the shaft; wherein the shaft comprises a helically wound coil extending distally from the housing along a longitudinal axis of the shaft, a distal end of the coil being spaced proximally from a distal, tissue-penetrating tip of the tissue-penetrating member; and one or more tissue fixation members located near the distal end of the housing and configured to fixate the housing to cardiac tissue.

[0204] Embodiment 42 is the device of Embodiment 41, wherein the helically wound coil comprises a first helically wound coil, and the shaft further comprises a second helically wound coil extending distally from the housing along the longitudinal axis of the shaft, the first helically wound coil being disposed around the second helically wound coil.

[0205] Embodiment 43 is the device of Embodiment 42, wherein an outer diameter of the second helically wound coil abuts an inner diameter of the first helically wound coil.

[0206] Embodiment 44 is the device of Embodiment 42 or Embodiment 43, wherein the first and second helically wound coils are wound in opposite directions.

[0207] Embodiment 45 is the device of Embodiment 42 or Embodiment 43, wherein the first and second helically wound coils are wound in opposite directions, such that when torsion is applied to the shaft, each coil produces a torque in a direction opposing that of the torque of the other coil.

[0208] Embodiment 46 is the device of any of Embodiments 41-45, wherein the shaft further comprises a steroid eluting device disposed between the first helically wound coil and the first electrode.

[0209] Embodiment 47 is the device of Embodiment 46, wherein the steroid eluting device has an annular configuration.

[0210] Embodiment 48 is the device of Embodiment 46 or Embodiment 47, wherein an outer surface of the steroid eluting device is exposed to contact with tissue.

[0211] Embodiment 49 is the device of Embodiment 48, wherein the outer surface of the steroid eluting device is flush with the outer surface of the shaft.

[0212] Embodiment 50 is the device of Embodiment 41, wherein the shaft further comprises a core member extending along the longitudinal axis of the shaft, the core member disposed within the helically wound coil.

[0213] Embodiment 51 is the device of Embodiment 43, wherein the shaft further comprises a core member extending along the longitudinal axis of the shaft, the core member disposed within the second helically wound coil, an outer diameter of the core member abutting an inner diameter of the second helically wound coil.

[0214] Embodiment 52 is the device of Embodiment 50 or Embodiment 51, wherein the core member is tubular.

[0215] Embodiment 53 is the device of any of Embodiments 41-52, wherein the shaft is tubular.

[0216] Embodiment 54 is the device of any of Embodiments 41-53, further comprising a sharp, tissue penetrating tip member positioned at the distal end of the shaft, wherein an outer surface of the tip member forms the first electrode.

[0217] Embodiment 55 is the device of Embodiment 54, wherein the tip member is cone shaped.

[0218] Embodiment 56 is the leadless implantable medical device of any of Embodiments 41-55, wherein the tissue penetrating member defines a member length, and wherein the member length is at least 5 millimeters (mm)and no more than 12 mm.

[0219] Embodiment 57 is the leadless implantable medical device of any of Embodiments 41-56, wherein the shaft defines a shaft length, and wherein the shaft length is at least 5 millimeters (mm) and no more than 9 mm.

[0220] Embodiment 58 is the leadless implantable medical device of any of Embodiments 41-57, wherein the shaft defines a shaft outer diameter, and wherein the shaft outer diameter is at least 2 French (Fr) and no more than 4 Fr.

[0221] Embodiment 59 is the leadless implantable medical device of any of Embodiments 41-58, wherein the tissue penetrating member defines a member Young’s Modulus, and wherein the member Young’s Modulus is at least 50 gigapascals (GPa) and no more than 500 GPa.

[0222] Embodiment 60 is the leadless implantable medical device of any of Embodiments 41-59, wherein the tissue penetrating member defines a member ShearModulus, and wherein the member electrode Shear Modulus is at least 20 gigapascals (GPa) and no more than 200 GPa.

[0223] Embodiment 61 is the leadless implantable medical device of any of Embodiments 41-60, wherein the leadless implantable medical device is configured to be delivered to the patient’s heart using the delivery device of Embodiment 1.

[0224] Embodiment 62 is the leadless implantable medical device of any of Embodiments 41-61, wherein the one or more tissue fixation members comprises a helix disposed around the tissue penetrating member.

[0225] Embodiment 63 is the leadless implantable medical device of any of Embodiments 41-62, further comprising a surface electrode disposed on the distal end of the housing and configured to pace myocardial tissue of the heart.

[0226] Embodiment 64 is the leadless implantable medical device of any of Embodiments 41-63, wherein the tissue penetrating member comprises a spear electrode.

[0227] Embodiment 65 is the leadless implantable medical device of any of Embodiments 41-64, wherein the circuitry is configured to sense electrical activity of the patient’s heart proximate an LBB area, and initiate delivery of pacing to the patient’s heart proximate the LBB area.

[0228] Embodiment 66 is the leadless implantable medical device of any of Embodiments 41-64, wherein the circuitry, together with the first electrode positioned at the distal end of the tissue penetrating member, is configured to sense electrical activity of the patient’s heart proximate an LBB area, and initiate delivery of pacing to the patient’s heart proximate the LBB area.

[0229] Embodiment 67 is the leadless implantable medical device of any of Embodiments 42-64, wherein the first helically wound coil defines a coil pitch of zero.

[0230] Embodiment 68 is the leadless implantable medical device of any of Embodiments 42-64, wherein the second helically wound coil defines a coil pitch of zero.

[0231] Embodiment 69 is a system comprising: a leadless implantable medical device comprising a spear electrode and configured to be implanted in a patient’s right ventricular (RV) septal wall and perform at least one of sensing and pacing of the patient’s left bundle branch (LBB) area using the spear electrode; and a delivery device comprising a deployment tube and a sleeve and configured to orient a distal end of the leadless implantable medical device perpendicular to the patient’s RV septal wall, the deliverydevice further configured to implant the leadless implantable medical device in the patient’s RV septal wall, wherein the spear electrode defines a spear electrode elasticity, the deployment tube defines a deployment tube elasticity, and the sleeve defines a sleeve elasticity, and wherein the spear electrode elasticity, the deployment tube elasticity, and the sleeve elasticity are each optimized for enabling LBB area pacing.

[0232] Embodiment 70 is the system of Embodiment 69, wherein the spear electrode elasticity is defined by a member Young’s Modulus and a spear electrode Shear Modulus, wherein the member Young’s Modulus is at least 50 gigapascals (GPa) and no more than 500 GPa, and wherein the member Shear Modulus is at least 20 GPa and no more than 200 GPa.

[0233] Embodiment 71 is the system of Embodiment 69 or Embodiment 70, wherein the deployment tube elasticity is defined by a deployment tube Young’s Modulus and a deployment tube Shear Modulus, wherein the deployment tube Young’s Modulus is at least 50 gigapascals (GPa) and no more than 500 GPa, and wherein the deployment tube Shear Modulus is at least 20 GPa and no more than 200 GPa.

[0234] Embodiment 72 is the system of any of Embodiments 69-71, wherein the sleeve elasticity is defined by a sleeve Young’s Modulus and a sleeve Shear Modulus, wherein the sleeve Young’s Modulus is at least 50 gigapascals (GPa) and no more than 500 GPa, and wherein the sleeve Shear Modulus is at least 20 GPa and no more than 200 GPa.

[0235] Embodiment 73 is the system of any of Embodiments 69-72, wherein, when the spear electrode elasticity, the deployment tube elasticity, and the sleeve elasticity are each optimized for LBB area pacing, the leadless implantable medical device resists mechanical fatigue.

[0236] Embodiment 74 is a system comprising: a delivery catheter housing the device of any of Embodiments 43-63 or 65-68 in a cup having a distal opening; wherein the tissue penetrating member and the one or more tissue fixation members are pointed distally within the cup toward the distal opening, such that the device can be fixated in cardiac tissue and the first electrode at the tip of the tissue penetrating member can electrically couple to the LBB area of the patient’s heart in response to a distal push force applied to the device.

[0237] Thus, various embodiments of IMPLANTABLE MEDICAL DEVICES AND DELIVERY SYSTEMS are disclosed. It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules associated with, for example, a medical device.

[0238] In one or more examples, 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).

[0239] Instructions may be executed by one or more 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. Accordingly, the term “processor” as used herein 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.

[0240] All references and publications cited herein are expressly incorporated herein by reference in their entirety for all purposes, except to the extent any aspect directly contradicts this disclosure.

[0241] All scientific and technical terms used herein have meanings commonly used in the art unless otherwise specified. The definitions provided herein are to facilitateunderstanding of certain terms used frequently herein and are not meant to limit the scope of the present disclosure.

[0242] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims may be understood as being modified either by the term “exactly” or “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein or, for example, within typical ranges of experimental error.

[0243] The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range. Herein, the terms “up to” or “no greater than” a number (e.g., up to 50) includes the number (e.g., 50), and the term “no less than” a number (e.g., no less than 5) includes the number (e.g., 5).

[0244] The terms “coupled” or “connected” refer to elements being attached to each other either directly (in direct contact with each other) or indirectly (having one or more elements between and attaching the two elements). Either term may be modified by “operatively” and “operably,” which may be used interchangeably, to describe that the coupling or connection is configured to allow the components to interact to carry out at least some functionality (for example, a mobile user device may be operatively coupled to a cellular network transmit data to or receive data therefrom).

[0245] Terms related to orientation, such as “top,” “bottom,” “side,” and “end,” are used to describe relative positions of components and are not meant to limit the orientation of the embodiments contemplated. For example, an embodiment described as having a “top” and “bottom” also encompasses embodiments thereof rotated in various directions unless the content clearly dictates otherwise.

[0246] Reference to “one embodiment,” “an embodiment,” “certain embodiments,” or “some embodiments,” etc., means that a particular feature, configuration, composition, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. Thus, the appearances of such phrases in various places throughout are not necessarily referring to the same embodiment of the disclosure.Furthermore, the particular features, configurations, compositions, or characteristics may be combined in any suitable manner in one or more embodiments.

[0247] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and / or” unless the content clearly dictates otherwise.

[0248] As used herein, “have,” “having,” “include,” “including,” “comprise,” “comprising” or the like are used in their open-ended sense, and generally mean “including, but not limited to.” It will be understood that “consisting essentially of,” “consisting of,” and the like are subsumed in “comprising,” and the like.

[0249] The term “and / or” means one or all of the listed elements or a combination of at least two of the listed elements.

[0250] The phrases “at least one of,” “comprises at least one of,” and “one or more of’ followed by a list refers to any one of the items in the list and any combination of two or more items in the list.

[0251] In the foregoing detailed description, the invention has been described with reference to specific embodiments. However, it may be appreciated that various modifications and changes can be made without departing from the scope of the invention as set forth in the appended claims.

Claims

CLAIMS1. A delivery device configured to deliver an implantable medical device to a patient’s heart from a supracardiac vascular location, the delivery device comprising: a deployment tube extending from a proximal end to a distal end and defining a length and an outer perimeter measured orthogonal to the length, the deployment tube further defining a curve along a curved portion of the length of the deployment tube, the curve comprising a first shape; a handle coupled to the proximal end of the deployment tube, the handle controllable by a user to control the delivery device; a cup coupled to the distal end of the deployment tube, the cup configured to house a leadless implantable medical device; and a movable sleeve disposed around the outer perimeter of the deployment tube, the movable sleeve configured to move from a first undeployed position to a second deployed position and manipulate the curve from the first shape to a second shape.

2. The delivery device of claim 1, wherein a radius of curvature of the curve is smaller in the second shape than in the first shape.

3. The delivery device of claim 1, wherein a lateral extension dimension measured from a distal end of the cup to a longitudinal axis of a proximal portion of the deployment tube is smaller in the second shape than in the first shape.

4. The delivery device of claim 1, wherein an included angle of the cup relative to a proximal portion of the deployment tube is adjustable via a pull wire.

5. The delivery device of claim 4, wherein the included angle of the cup is adjustable to 45 degrees or more.

6. The delivery device of claim 1, wherein the second deployed position is distal of the first undeployed position.

7. The delivery device of claim 1, wherein, in the second deployed position, a distal end of the movable sleeve is within 5 cm of a proximal end of the cup.

8. The delivery device of claim 1, wherein movement of the movable sleeve toward the second deployed position shortens an articulatable segment of the deployment tube.

9. The delivery device of claim 1, wherein the location of the second deployed position is user selectable within a range of movement of the movable sleeve.

10. The delivery device of claim 1, wherein, when the movable sleeve is in the first undeployed position, the movable sleeve is located proximate the handle.

11. The delivery device of claim 1, wherein, when the movable sleeve is in the second deployed position, the movable sleeve is located proximate the cup.

12. The delivery device of claim 1, wherein, when the movable sleeve is in the second deployed position, the cup has a range of motion in response to operation of a pull wire that includes an orientation perpendicular to a right ventricular (RV) septal wall of the patient’s heart.

13. The delivery device of claim 1, wherein, when the movable sleeve is in the second deployed position, the cup has a range of motion in response to operation of a pull wire that includes a location between the patient’s His bundle and a point midway between the patient’s His bundle and the patient’s right ventricular (RV) apex.

14. The delivery device of claim 1, wherein the movable sleeve defines a movable sleeve length, and wherein the movable sleeve length is at least 5 centimeters (cm) and no more than 50 cm.

15. The delivery device of claim 1, wherein an inner diameter of the movable sleeve is less than an outer diameter of the cup, and optionally wherein an outer diameter of the deployment tube is less than an outer diameter of the cup.

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