Tether assembly for medical device delivery system

Abstract

In some instances, a tethered head assembly of a delivery system includes an inner retainer and an outer retainer defining an orifice comprising a container configured to receive an attachment member of a medical device, a passage, and a recess. The inner retainer is movable within the recess between a second position and a first position, in which the passage is sized to receive the attachment member, and in the first position, the passage is sized to prevent the attachment member from passing through. A tethered handle assembly defines a channel, a force transmitter within the channel, a slidable member partially received at a first end of the channel, and a button partially received at a second end of the channel. A distally directed force applied to the button causes the force transmitter to apply a proximally directed force to the slidable member, thereby moving the slidable member and the attached tether proximally.

Description

Technical Field

[0001] This disclosure relates generally to medical devices, and more specifically to systems for delivering medical devices. Background Technology

[0002] Some types of implantable medical devices (IMDs), such as pacemakers or implantable cardioverter-defibrillator systems, can be used to provide cardiac sensing and therapy to a patient via one or more electrodes. As an example, some IMDs include an implantable pulse generator comprising a housing enclosing electronic components, which can be configured for subcutaneous implantation in a patient's chest or within a cavity of the patient's heart. IMDs with a pulse generator configured for implantation within a cavity of the heart can be referred to as intracardiac devices or leadless implantable medical devices. Medical device delivery systems including delivery catheters can be used to deliver intracardiac devices intravenously to an implantation site within the patient's heart and release the device after it has been secured at the implantation site. The medical device delivery system can then be withdrawn from the patient. Summary of the Invention

[0003] Typically, this disclosure relates to examples of tether assemblies for medical device delivery systems and to techniques for using such tether assemblies. Example tether assemblies may include a distal tether head assembly configured to releasably retain an attachment member of a medical device, such as an intracardiac device. Alternatively, the tether assembly for a medical device delivery system may include a tether handle assembly configured to retain a proximal end of a pull wire of the tether assembly. The tether handle assembly includes one or more components (e.g., actuators) configured to transmit force through the pull wire to the tether head assembly. The technique may involve applying a force to the actuator of the tether handle assembly to move the pull wire, thereby removing the attachment member from the tether head assembly at a treatment site.

[0004] The tether head assembly may include an inner retainer and an outer retainer. The outer retainer may define an orifice comprising: a container configured to receive an attachment member of a medical device; and a passage extending proximally from a distal end of the outer retainer to the container. The orifice may further include a groove extending proximally from the distal end of the outer retainer at least to the container.

[0005] The internal retainer is movable between a first position and a second position. When the internal retainer is in the first position, the distal portion of the internal retainer can be partially received in the recess and extend into the passage, thereby narrowing the passage. Therefore, the size of the passage can be set to prevent the attachment member from passing through it when the internal retainer is in the first position, such as during a medical procedure for delivering the medical device, when the attachment member is loaded onto the tether assembly, preventing the attachment member from passing through the container. When the internal retainer is in the second position, the internal retainer does not narrow the passage, and therefore, the size of the passage can be set to receive the attachment member of the medical device as the medical device is being loaded onto or released from the tether assembly.

[0006] The inner retainer can be biased to the first position. When the proximal movement of the pull cord is interrupted and / or when the attachment member has passed through the passage and is housed within the container defined by the outer member, the resiliently compressible member of the tether head assembly can expand and apply a distal force to the inner retainer, thereby moving the inner retainer from the second position to the first position.

[0007] In other instances, a tether head assembly configured to hold the attachment member of a medical device may include a retainer or other such component that will not be biased back to this first position. The act of loading a medical device onto such other tether assemblies before delivery to a patient's heart may require two people (e.g., a clinician). It may be necessary for a first person to hold the medical device in place while a second person opens the tether head assembly, such as by moving the pull cord of the tether assembly proximally to move the internal retainer from a first position where the tether assembly is "closed" to a second position where the tether assembly is "open." The first person can then load the attachment member of the medical device onto the tether head assembly (e.g., by placing the attachment member in a container defined by the tether head assembly), and the second person can move the pull cord distally to return the tether head assembly to the first position and retain the attachment member within the container. Using two people to load the medical device onto the tether assembly may increase the time and complexity of the medical procedure for delivering the medical device and / or may increase the likelihood of contamination of the medical device or other objects within the surgical area.

[0008] The example tether head assembly described herein allows one person, rather than two, to load a medical device onto the tether assembly. For example, biasing the inner retainer to a first position allows a clinician to hold the tether head assembly with one hand and simply press the attachment member into the passage defined by the outer retainer, thereby causing the inner retainer to move to a second position as the attachment member moves through the passage into the container, compressed by the resiliently compressible member of the tether head assembly. The bias of the inner retainer to the first position provided by the resiliently compressible member allows the clinician to release his or her grip on the medical device once the attachment member is housed in the container, thus allowing the inner retainer to return to the first position.

[0009] In this way, the tether assembly described herein can reduce the time and complexity associated with procedures used to deliver medical devices. In some instances, the tether assembly described herein can reduce the likelihood of contamination of other objects within the medical device or surgical area by reducing the number of people who touch the medical device and the tether assembly. In some instances, the tether assembly described herein can provide one or more advantages in terms of functionality, reliability, robustness, manufacturability, and cost associated with such tether assemblies.

[0010] In some instances, the tether handle assembly as described herein can be used in conjunction with a tether head assembly and a common pull cord as described herein. As an example, the tether assembly may include a tether head assembly, a pull cord, and a tether handle assembly attached to the proximal end of the pull cord. The tether handle assembly may include an actuator configured to cause proximal movement of the pull cord, enabling removal of the attachment member from the tether head assembly. Applying a force to the actuator can cause proximal movement of the pull cord, allowing the medical device to be released from the tether head assembly at a treatment site within the patient's body (e.g., inside the patient's heart). The force applied to the actuator may be a distal force, such as a button push. In such instances, one or more components of the tether handle assembly may be configured to convert the distal force applied to the actuator into a proximal force applied to the pull cord.

[0011] Examples of tethered handle assemblies in medical device delivery systems that are configured to release the medical device from the tether assembly by converting a distal force into a proximal force may offer one or more advantages. In some instances, clinicians may find applying a distal force (i.e., a thrust) to a button or sliding member to release the medical device more intuitive and / or easier in other ways than some other tethered handle assembly configurations. In some instances, clinicians are less likely to accidentally release the medical device when using a tethered handle assembly configured to release the medical device from the tether assembly by a distal force relative to other actuator configurations.

[0012] Any such tethered handle assembly may include one or more components, such as locking members or covers, configured to reduce the likelihood of accidental release of the medical device from the tethered assembly. Alternatively or additionally, any handle assembly described herein may enable sensing of electrical signals via an electrical path including the medical device and one or more components of the tethered assembly containing the tethered handle assembly. This can help clinicians determine the delivery and positioning of the medical device relative to target tissue, the attachment of the medical device to the target tissue, and how much force to apply to the actuator of the tethered handle assembly to release the medical device from the tethered assembly.

[0013] In some other instances, the tether assembly of a medical device delivery system may be non-reusable, such as in instances where the tether assembly includes a loop that passes through the medical device and is then cut after the medical device is secured at the treatment site, or other such components. In these other instances, a new tether assembly and / or medical device delivery system may therefore be packaged with each medical device. Packaged with the medical device delivery system and / or tether assembly with the medical device may be related to shelf-life considerations, such as in instances where the medical device includes a drug elution component that may have an expiration date.

[0014] The example tether assemblies described herein can be sterilizable and reusable, at least in part because they can be released from a medical device without being cut. In some instances, the tether assembly can be packaged separately from the medical device, such as in cases where the medical device may contain a drug elution assembly with a limited shelf life. In such cases, packaging the tether assembly separately from the medical device can alleviate concerns regarding the shelf life of the tether assembly.

[0015] Therefore, the example tether assembly described herein enables a person to load a medical device onto the tether assembly, is more intuitive for clinicians to operate on than some other example tether assemblies, reduces the likelihood of accidental deployment of the medical device, enables clinicians to determine the placement of the medical device at the treatment site in the patient's body (e.g., within the patient's heart), and / or enables clinicians to monitor electrical signals from the distal portion of the medical device and / or delivery system during the implantation procedure.

[0016] In one example, a tether assembly of a medical device delivery system includes a pull cord and a tether head assembly, the pull cord defining a proximal and a distal end. The tether head assembly includes an inner retainer comprising a proximal portion and a distal portion, wherein the inner retainer is coupled to and extends distally from the distal end of the pull cord; and an outer retainer comprising a proximal portion and a distal portion, the proximal portion defining a channel configured to receive the inner retainer, and the distal portion defining an orifice. The orifice includes: a container configured to receive an attachment member of a medical device; a passage extending proximally from the distal end defined by the outer retainer to the container, wherein the passage is narrower than the container; and a groove extending proximally from the distal end of the outer retainer to at least the container, wherein the depth of the groove is less than the thickness of the distal portion of the inner retainer. The internal retainer is movable between a first position and a second position, in which the distal portion of the internal retainer is partially received in the groove and extends into the passage, thereby narrowing the passage, and in the second position, the distal portion of the internal retainer is positioned proximal to the passage.

[0017] In another example, a tether assembly for a medical device delivery system includes a tether handle assembly comprising: a housing defining a curved channel defining a first end and a second end; a force transmitter housed within the curved channel; a slidable member housed within the housing such that a portion of the slidable member is housed within the channel at the first end of the channel; and a button defining a proximal surface and including a distal portion housed within the channel at the second end of the channel, wherein the button surrounds at least the proximal portion of the slidable member. The tether assembly further includes a pull cord defining a proximal end and a distal end, wherein the proximal end of the pull cord is housed within the housing and held by the slidable member. The button is configured to move from a first position to a second position in response to a force applied to the button toward the distal side, thereby moving the force transmitter toward the first end of the curved channel, such that the force transmitter applies a force toward the proximal side to the portion of the sliding member housed within the channel, the force toward the proximal side causing the sliding member and the pull cable to move proximally.

[0018] In another example, a method for using a tether assembly of a medical device delivery system includes positioning the tether head assembly of the tether assembly at a treatment site of a patient using an attachment member of the medical device housed within a container of the tether head assembly, the tether head assembly being configured to releasably retain the attachment member of the medical device. The tether head assembly includes an inner retainer comprising a proximal portion and a distal portion, wherein the inner retainer is coupled to and extends distally from the distal end of a drawstring of the medical device delivery system; and an outer retainer comprising a proximal portion and a distal portion, the proximal portion defining a channel configured to receive the inner retainer, and the distal portion defining an orifice. The orifice includes: a container configured to receive the tethering member of the medical device; a passage extending proximally from the distal end of the outer retainer to the container, wherein the passage is narrower than the container; and a groove extending proximally from the distal end of the outer retainer to at least the container, wherein the depth of the groove is less than the thickness of the distal portion of the inner retainer. Positioning the tethering head assembly includes positioning the tethering head assembly having the inner retainer in a first position, in which the distal portion of the inner retainer is partially received in the groove and extends into the passage, thereby narrowing the passage, wherein the size of the passage is set to prevent the attachment member from passing through when the inner retainer is in the first position. The method further includes applying a force to an actuator of the tether assembly to cause proximal movement of the pull cord, the proximal movement of the pull cord causing the inner retainer to move from a first position to a second position, in which the distal portion of the inner retainer is positioned proximal to the passage, wherein the passage is sized to receive the attachment member of the medical device when the inner retainer is in the second position, thereby allowing the attachment member of the medical device to pass through the passage from the container. The method further includes using the inner retainer in the second position to move the tether assembly proximally to remove the attachment member of the medical device from the tether head assembly, thereby delivering the medical device to the treatment site.

[0019] In another example, a tether assembly for a medical device delivery system includes a tether handle assembly comprising: a housing; a first slidable member defining a first orifice and housed within the housing; a second slidable member housed within the first orifice and defining a second orifice; and at least one gear housed within the orifice defined by the first slidable member and configured to mechanically engage the first slidable member and the second slidable member. The tether assembly further includes a pull cord defining a proximal end and a distal end, wherein the proximal end of the pull cord is housed within the housing and held by the second slidable member. The first slidable member is configured to move distally in response to a force applied distally to the first slidable member, and as the first slidable member moves distally, the at least one gear causes the second slidable member and the pull cord to move proximally.

[0020] In another example, a tether assembly for a medical device delivery system includes a tether handle assembly comprising a housing, a slidable member within the housing, and a plunger coupled to and extending distally from the slidable member. The tether assembly further includes a pull cord defining a proximal and a distal end, wherein the proximal end of the pull cord is received within the housing and held proximally by the slidable member. The plunger is configured to move from a first position to a second position in response to a force applied proximally to the plunger, the proximal force causing the slidable member and the pull cord to move proximally.

[0021] In another example, a method for using a tether assembly in a medical device delivery system includes positioning the tether head assembly of the tether assembly at a patient's treatment site using an attachment member of the medical device housed within a container of the tether head assembly, the tether head assembly being configured to releasably retain the attachment member of the medical device. The method further includes: applying a force in a distal direction to an actuator of the tether handle assembly of the tether assembly to cause proximal movement of the pull cord, the proximal movement of the pull cord causing the tether head assembly to open; and, with the tether head assembly open, moving the tether assembly proximally to remove the attachment member of the medical device from the tether head assembly, thereby delivering the medical device to the treatment site.

[0022] The present invention is intended to provide an overview of the subject matter described herein. It is not intended to provide an exclusive or exhaustive interpretation of the apparatuses and methods described in detail in the following drawings and description. Further details of one or more examples are set forth in the drawings and the following description. Attached Figure Description

[0023] Figure 1 It is a concept diagram showing part of the patient anatomy that includes potential implantation sites for implantable medical devices (IMDs);

[0024] Figure 2 This is a floor plan illustrating an example medical device delivery system for positioning an IMD within the heart;

[0025] Figure 3 It shows a sample IMD. Figure 2 A conceptual diagram illustrating the integration of the distal portion of an example medical device delivery system with cardiac tissue;

[0026] Figure 4A It is a plan view of the distal portion of an example tether assembly including a tether head assembly and a pull cord, wherein the outline of the distal portion of the tether head assembly is depicted.

[0027] Figure 4B yes Figure 4A An exploded plan view of the distal portion of an example tether assembly, which depicts the outline of the distal portion of the internal retainer of the tether head assembly.

[0028] Figure 4C yes Figure 4B A plan view depicting the distal portion of the internal retainer, outlining its contours;

[0029] Figure 4D yes Figure 4A A plan view of the distal portion of the tether head assembly, outlining its contours.

[0030] Figure 5A Is with Figure 3 The side view of the IMD combined Figures 4A-4D A side view of the distal portion of an example tether assembly, wherein the tether head assembly and the IMD are not connected;

[0031] Figure 5B yes Figure 5A A cross-sectional view of the proximal portion of the tether head assembly and the IMD, wherein the cross-section is along a plane parallel to the longitudinal axis of the tether head assembly and the longitudinal axis of the IMD. Figure 5A The line AA was intercepted;

[0032] Figure 5C yes Figure 5A A cross-sectional view of the proximal portion of the tether head assembly and the IMD, showing the inner retainer in a second position and the attachment member of the IMD within a container defined by the outer retainer.

[0033] Figure 5D yes Figure 5A A cross-sectional view of the proximal portion of the IMD, including the tether head assembly and the IMD, wherein the attachment member of the IMD is held in a first position by an inner retainer within a container defined by an outer retainer.

[0034] Figure 6A This is an exploded view of the distal portion of another example tether assembly, including the tether head assembly and the guy line, which depicts... Figure 6A The outline of the distal portion of the internal retainer of the tether head assembly;

[0035] Figure 6B yes Figure 6A A plan view depicting the distal portion of the internal retainer, outlining its contours;

[0036] Figure 6C It is stored in Figure 6A The outer retainer of the tether head assembly Figure 6B A plan view of the distal portion of the internal retainer;

[0037] Figure 6D yes Figure 6A Example tether head assembly and Figure 3 A cross-sectional view of the proximal portion of the IMD, wherein the cross-section is taken along a plane parallel to the longitudinal axis of the tether head assembly and the longitudinal axis of the IMD.

[0038] Figure 7 This is a functional block diagram showing a sample configuration of IMD;

[0039] Figure 8 It demonstrates how to use Figure 4A-6D A flowchart illustrating an example technology for a tethering assembly;

[0040] Figure 9A This is a plan view of an example tether handle assembly, showing the proximal portion of another example tether assembly.

[0041] Figure 9B yes Figure 9A Exploded plan view of the tether handle assembly;

[0042] Figure 10A-10D yes Figure 9A and 9B A side view of a tether handle assembly, wherein a portion of the housing of the tether handle assembly has been removed, the side view showing... Figure 9A and 9B The force transmitter, sliding member, and pull line of the example tether assembly move in response to the button of the tether handle assembly moving from a first position to a second position;

[0043] Figure 11A-11J yes Figure 9A and 9B A plan view of the components of an example tether assembly and a tether handle assembly, which illustrates an example technique for assembling the tether handle assembly;

[0044] Figures 12A-12E This is a plan view of another example of a tether assembly, a tether handle assembly including a cover for a button;

[0045] Figure 13A and 13B It is a plan view of the proximal end of another example tether assembly, which includes another example tether handle assembly;

[0046] Figure 13C yes Figure 13A and 13B An exploded plan view of an example tether handle assembly;

[0047] Figure 13D and 13E yes Figures 13A-13C A plan view of an example tether handle assembly, wherein a portion of the housing has been removed, the plan view showing multiple gears, a second sliding member, and a pull cord of the example tether handle assembly in response to the movement of a first sliding member of the tether handle assembly from a first position to a second position;

[0048] Figure 14 This is a flowchart illustrating an example technology for using a medical device delivery system comprising a tether assembly, the tether assembly including, as described above... Figure 9A-13E The described tether handle assembly and about Figure 4A-6D The described tether head assembly;

[0049] Figure 15A This is a side view of another example tether assembly, which includes another example tether handle assembly;

[0050] Figure 15B yes Figure 15A Exploded plan view of the tether handle assembly;

[0051] Figure 15C-15E yes Figure 15A and 15B A perspective view of a tethered handle assembly, with a portion of the housing removed, showing different positions of the locking member and plunger of the tethered handle assembly;

[0052] Figure 16A This is an exploded plan view of another example of a tether handle assembly;

[0053] Figure 16B yes Figure 16AA cross-sectional view of an example tether handle assembly;

[0054] Figure 17A This is an exploded plan view of another example of a tether handle assembly;

[0055] Figure 17B yes Figure 17A A cross-sectional view of an example tether handle assembly; and

[0056] Figure 17C yes Figure 17A A plan view of the plunger collar portion of an example tethered handle assembly. Detailed Implementation

[0057] Generally, this disclosure describes an example medical device delivery system. Such a medical device delivery system may include a tether assembly comprising a tether head assembly, a tether handle assembly, and a pull cord. The tether head assembly is attached to the pull cord and configured to releasably retain an attachment member of a medical device (e.g., an intracardiac device). In some instances, the tether handle assembly is configured to retain the pull cord attached to the tether head assembly. The tether handle assembly may include an actuator configured to transmit force through the pull cord to the tether head assembly and to remove the attachment member of the medical device from the tether head assembly at a treatment site within the patient's body. Although the example tether assemblies are generally described herein as being configured for delivery of implantable medical devices (IMDs), it should be understood that any of the example tether assemblies described herein may alternatively be configured for delivery of other types of medical devices.

[0058] Figure 1 This is a conceptual diagram illustrating a portion of the patient's anatomy, including potential implantation sites for an IMD. For example, the IMD could be implanted on or within the patient's heart 1, such as within an appendage 2 in the right atrium (RA), within the coronary vein (CV) via the coronary sinus ostium (CSOS), or near the apex 3 of the right ventricle (RV). In other instances, the IMD could be implanted in other locations within the heart 1 or in locations other than the heart 1, such as any suitable implantation site within the patient's body.

[0059] Figure 2 It demonstrates the use of IMD ( Figure 1 A plan view of an example medical device delivery system 4 (not shown) for delivery into the heart 1. Although described herein in the context of delivering an IMD to a vascular system such as the heart 1, the devices, systems, and techniques disclosed herein can be used to deliver an IMD to any anatomical location.

[0060] System 4 includes a guide 5, a delivery catheter 6, and a tether assembly 12. The guide 5 is an elongated member defining an internal lumen. The guide 5 is configured, as if inserted by a physician into a patient's vascular system, to provide a rigid passage through the internal lumen through which a medical device, apparatus, or other therapy is inserted.

[0061] The delivery catheter 6 is configured to be inserted through the lumen of the guide 5 to deliver IMD within a vascular system. The delivery catheter 6 includes an elongated shaft 9, a handle 7, and a device cup 8. As an example, the handle 7 is located at the proximal end of the shaft 9 and may include one or more elements (such as a button, switch, etc.) configured to control movement of the distal end of the shaft 9 and release of the IMD from the device cup 8.

[0062] The device cup 8 is positioned at the distal end of the shaft 9. The device cup 8 comprises components configured to receive and support the IMD when it is implanted within the patient's vascular system (e.g., regarding...). Figure 3 The IMD (10) described is a hollow cylindrical body. For example, a physician can insert the distal end of a delivery catheter 6 containing a device cup 8 through the lumen of a guide 5 placed within the patient's vascular system. Once the device cup 8 has extended through the distal end of the guide 5 and reached the implantation site in the patient's body, the physician can release the IMD from the distal opening 11 of the device cup 8 and withdraw the delivery catheter 6 proximally through the guide 5.

[0063] The tether assembly 12 extends through a delivery conduit defined by an inner lumen, which includes, for example, a handle 7 and a shaft 9. The tether assembly 12 includes an elongated body 20, a tether handle assembly 13 at the proximal end of the elongated body 20, and a tether head assembly 18 at the distal end of the elongated body 20. Figure 3 Pulling wire () Figure 2 (Not shown) can extend from the tether handle assembly 13 to the tether head assembly 18 through an inner cavity defined by the elongated body 20.

[0064] The tether assembly 12 may be of sufficient length to allow a clinician to manipulate the tether handle assembly 13 to advance the tether head assembly 18 beyond the distal opening 11 of the cup 8. In some instances, with the tether head assembly 18 outside the cup 8 as described herein, the clinician may attach the IMD to the tether head assembly 18. The clinician may then load the IMD into the cup 8 through the distal opening 11 and advance the delivery catheter 6 through the guide 5 and into the vascular system using the tether assembly 12 and the IMD therein.

[0065] Figure 3This is a conceptual diagram showing the distal portion of an example medical device delivery system 4 carrying an example IMD 10 integrated with tissue 15 of the heart 1. The IMD 10 may be a pacemaker device with a housing 80 containing electronic components suitable for performing various pacing functions. However, an IMD configured to deliver other types of electrotherapy to a patient may be adapted for use with the delivery system 4. The IMD 10 may include an attachment member 14 at its proximal end and a fixation member 16 at its distal end. A tether head assembly 18 may be configured to receive and retain the attachment member 14, as described below. Figures 4A-5D Further discussion is needed.

[0066] In some instances, the IMD 10 may include a hermetically sealed housing 80 defining a proximal end 82 and a distal end 84. The housing 80 may contain a pulse generator and associated power supply (not shown) and electrodes 86, which may be positioned at the distal end 84 of the housing 80 and electrically coupled to the pulse generator of the IMD 10 via a hermetically sealed feedthrough assembly (not shown). The housing 80 may be formed of any suitable biocompatible and biostable metal. For example, the housing 80 may be formed of titanium and may be covered with an insulating layer (e.g., medical-grade polyurethane, parylene, or silicone). In some instances, the IMD 10 may include a housing electrode 88, which may be formed by removing portions of the insulating layer to expose the metal surface defined by the housing 80. In such instances, the housing electrode 88 of the IMD 10 may function in conjunction with the electrode 86, such as for bipolar pacing and sensing.

[0067] Figure 3 A cup-shaped portion 8 of the delivery catheter 6, pressed against tissue 15 at the implantation site of the heart 1, is shown. When the clinician is satisfied with the positioning of the cup-shaped portion 8 relative to the tissue 15, for example, when the longitudinal axis of the cup-shaped portion 8 is generally orthogonal to the plane defined by the tissue 15 and the cup-shaped portion 8 is sufficiently pressed against / indented into the tissue 15 such that the fixation member 16 of the IMD 10 will unfold into the tissue, the clinician can use the tether assembly 12, for example, by advancing the tether assembly 12 distally relative to the delivery catheter 6 using the tether assembly handle 13, to advance the IMD 10 toward the distal opening. The fixation member 16 can be configured to embed in the tissue 15 and, in some cases, pull the IMD 10 through the distal opening 11 of the cup-shaped portion when advanced through the distal opening. Although the IMD 10 is shown to have a fixation member 16 comprising multiple toothed structures, it should be understood that the IMD 10 may include one or more other suitable fixation structures, such as a spiral fixation member (spiral) that can be rotated into the tissue at the implantation site.

[0068] The IMD 10 can be temporarily attached to the tether assembly 12 via the attachment member 14 and the tether head assembly 18, while being secured to the tissue 15 via the fixation member 16. Therefore, the clinician can test the fixation of the IMD 10 at the implantation site and / or, if necessary, remove the IMD 10 from the implantation site and return it to the cup 8 for repositioning at a more suitable location. Once the implantation of the IMD 10 is satisfactory, the clinician can detach the tether head assembly 18 from the attachment mechanism 14 and move the tether assembly 12 proximally, as described in more detail below, and then withdraw the delivery catheter 6 and the tether assembly 12 from the patient via the guide 5.

[0069] For example, the tether assembly 12 may include, as about Figures 4A-5D A guy cable (not shown) is discussed in further detail. This guy cable can be attached to the tether head assembly 18 at its distal end and to the tether handle assembly 13 at its proximal end, as discussed below. Figure 9A-17C Examples of the tether head assembly and the tether handle assembly are discussed. A clinician can apply force to the actuator of the tether handle assembly to move the tether head assembly 18 from a closed position to an open position, in which the attachment member 14 is retained within the tether head assembly 18, and in the open position, the attachment member 14 can be removed from the tether head assembly 18. With the tether head assembly 18 in the open position, the clinician can move the tether assembly 12 proximally to remove the attachment member 14 from the tether head assembly 18, thereby securing the IMD 10 at the treatment site.

[0070] Clinicians can secure the attachment member 14 to the tether head assembly 18 by pressing it into the passage defined by the tether head assembly 18, thereby opening the tether head assembly 18 from a first (e.g., closed) position to a second (e.g., open) position and advancing the attachment member 14 through the passage until the tether member 14 is received within the container defined by the tether head assembly 18, as described below regarding Figures 4A-5D This is discussed further. This can be done by a single clinician, whereas in some other example medical device delivery systems, two clinicians may be required to secure the IMD's attachment members to the tether assembly. Therefore, the tether assembly 12 can reduce the time and complexity associated with the procedure for delivering the IMD 10. In some instances, compared to other such tether assemblies, the tether head assembly 18 can reduce the likelihood of contamination of other objects within the medical device or surgical area by reducing the number of people touching the IMD 10 and the tether head assembly 18.

[0071] As described herein, clinicians can attach the attachment member 14 of the IMD 10 to the tether head assembly 18 during medical procedures for delivering the IMD 10. Additionally, clinicians can release the IMD 10 from the tether head assembly 18 without cutting any portion of the tether assembly 12. In some instances, the tether head assembly 18 can thus reduce or eliminate disadvantages that may be associated with other types of tethering mechanisms, such as tension associated with pulling on such other tethering mechanisms (e.g., cord loops or similar materials), potential torsion or binding of such other tethering mechanisms, etc. The reusability of the tether assembly 12 can alleviate shelf-life considerations regarding the tether assembly 12, delivery system 4, and IMD 10, as in instances where the IMD 10 includes a drug elution component with a limited shelf life. For example, when packaged separately from the IMD 10, the tether assembly 12 and / or delivery system 4 may not necessarily be associated with a limited shelf life.

[0072] During delivery of the IMD 10 to the treatment site via delivery system 4, the clinician can advance the cup 8 to contact the tissue 15 of the heart 1 before engaging the fixation member 16 with the tissue 15 of the heart 1. The clinician can then determine whether the cup 8 and IMD 10 are correctly positioned at the implantation site before engaging the fixation member 16 with the tissue 15 of the heart 1. In some instances, the clinician can determine whether the cup 8 and IMD 10 are correctly positioned relative to the heart 2 based on impedance or other electrical signals sensed through the electrical path containing the IMD 10 (e.g., housing 80 or electrode 88), attachment member 14, and tether assembly 12 (e.g., one or more components of tether head assembly 18). In addition to the IMD, another electrode in the electrical path can be a reference electrode attached to or inside the patient but positioned outside the cup 8. In some instances, a relatively high impedance can indicate that the cup 8 is positioned flush with the tissue 15 of the heart 1 and has sufficient depth in said tissue, which may be desired for proper fixation. After the fixation member 16 and IMD 10 are deployed from the cup 8, and with the IMD 10 secured to the tissue 15, impedance or electrical signals can also indicate the quality of fixation of the IMD 10 to the tissue, for example, based on changes in impedance during a “drag test” in which a clinician pulls the tether assembly 12 while the IMD 10 is attached to the tissue 15 and secured. Some examples may employ any of the techniques described in U.S. Patent Application Serial No. 16 / 146,391, filed September 28, 2018, entitled “Impedance-Based Verification of Delivery of Implantable Medical Devices”, by Medtronic, Inc., for testing the spatial relationship between the cup 8 and / or the IMD and the tissue, and for testing the fixation of the IMD to the tissue.

[0073] Figure 4A-6D An example of the distal portion of a tether assembly including an example tether head assembly is shown. It should be noted that, although this is possible with respect to IMD 10 pairs... Figure 4A-6D This is described, but the delivery system can be used to deliver other appropriately configured medical devices.

[0074] Figure 4A This is a plan view of the distal portion of the tether assembly 12, in which the components of the tether assembly 12 are in an assembled configuration, and the outline of the distal portion of the tether head assembly 18 is depicted. Figure 4B This is an exploded plan view of the distal portion of the tether assembly 12, which depicts the outline of the distal portion of the internal retainer 36 of the tether head assembly 18. Figure 4C yes Figure 4B A plan view of the distal portion of the internal retainer 36, outlining its contours. Figure 4D yes Figure 4A A plan view of the distal portion of the tether head assembly 18, whose outline is depicted in the figure.

[0075] like Figure 4A As shown, the elongated body 20 may include a shaft defining an inner cavity (not shown), within which a portion of the pull cord 34 is housed. The tether assembly 18 may include an inner retainer 36, an outer retainer 38, and a sheath 40. The components of the tether assembly 12 can be individually formed from any suitable material. In some instances, one or more of the pull cord 34, inner retainer 36, outer retainer 38, sheath 40, and / or one or more layers of the elongated body 20 may be formed from a conductive material, which can facilitate the control of the pull cord as described above. Figure 3 The IMD 10 under discussion was tested during placement in the procedure used to deliver the IMD 10. One or more components of the tether assembly 12 may be manufactured using techniques such as metal injection molding or any other suitable technique.

[0076] The inner retainer 36 can be coupled to the pull wire 34 and extends distally from the distal end (not shown) of the pull wire 34. The distal portion 56 of the outer retainer 38 defines an aperture 42, as shown. Figure 4B As shown, the orifice includes a container 44 and a passage 46, the container being sized to receive the attachment member 14 of the IMD 10. The passage 46 extends proximally from a distal end 48 defined by an external retainer 38 to the container 44 and may be narrower than the container 44.

[0077] The proximal portion 54 of the outer retainer 38 may define a channel (not shown) configured to receive the inner retainer 36. The inner retainer 36 may be received within the outer retainer 38 in a first position, in which the distal portion 52 of the inner retainer 36 extends into the passage 46, such as... Figure 4A and 4D As shown in the diagram, when the internal retainer 36 is in the first position, the size of the passage 46 can be set to prevent the attachment member 14 of the IMD 10 from passing through (e.g., too narrow to allow the attachment member 14 to pass through).

[0078] Proximal movement of the pull cord 34 can move the inner retainer 36 from a first position to a second position, in which the inner retainer 36 does not extend into the passage 46. Alternatively, applying force to the inner retainer 36 (e.g., the distal end of the inner retainer 36) via the attachment member 14 of the IMD 10 can move the inner retainer 36 from the first position to the second position. When the inner retainer 36 is in the second position, the passage 46 can be sized to accommodate the tether member 14. The inner retainer 36 and the outer retainer 38 can be accommodated within the sheath 40, and more specifically, within the cavity 64 defined by the sheath 40, which helps to hold the inner retainer 36 within the outer retainer 38 and to attach the outer retainer 38 to the elongated body 20.

[0079] In some instances, the configuration of the inner retainer 36 and the outer retainer 38 can substantially isolate the function of retaining the attachment member 14 of the IMD 10 to the tether head assembly 18 instead of the drawstring 34 or another element of the handle assembly extending to the tether assembly 12. For example, the path length of the drawstring 34 and / or shaft 20 can change as the tether assembly 12 is guided through a bend in the patient's vascular system. In some other example medical device delivery systems where the tether assembly relies on the drawstring to retain the attachment member within the tether head assembly, such changes in the path length of the drawstring and / or shaft can cause a loss of contact between the drawstring and the attachment member, thereby adversely affecting the retention of the attachment member during delivery.

[0080] In tether assembly 12 and other examples of tether assemblies described herein, variations in the path length of the drawstring 34 and / or shaft 20 of tether assembly 12 may not cause significant proximal or distal movement of the inner retainer 36. For example, the sheath 40 and / or the resiliently compressible member 60 may help reduce or prevent proximal movement of the inner retainer 36 when the path length of the drawstring 34 and / or shaft 20 changes during guidance through a curved vascular system. In this way, the substantial isolation of the IMD retention function within tether head assembly 18 may help maintain retention of attachment member 14 as tether assembly 12 is guided through a curved vascular system.

[0081] exist Figure 4B In the image, the outline of the distal portion of the internal retainer 36 is depicted, and... Figure 4C The portion of the internal retainer 36 is shown in more detail below. (See also...) Figure 4B As shown, the inner retainer 36 may include a proximal portion 50 and a distal portion 52. The outer retainer 38 may include a proximal portion 54 and a distal portion 56. The proximal portion 54 of the outer retainer 38 may define a channel (not shown) sized to receive the proximal portion 50 of the inner retainer 36. The distal portion 56 of the outer retainer 38 may define an orifice 42. In some embodiments, the orifice 42 may further include a groove 58 extending proximally from the distal end 48 of the outer retainer 38 to at least the container 44. The groove 58 may be partially defined by the distal portion 56 of the outer retainer 38 and may have a depth less than the thickness of the distal portion 52 of the inner retainer 36. The value by which the thickness of the distal portion 52 of the inner retainer 36 exceeds the depth of the groove 58 may correspond to a distance by which the inner retainer 36 extends, for example, laterally into the passageway 46 along the longitudinal axis defined by the inner retainer 36.

[0082] Figure 4B A resiliently compressible member 60 is further illustrated, which can be housed within a cavity 64 defined by a sheath 40, proximal to, for example, adjacent to, the inner retainer 36. The resiliently compressible member 60 can be formed of a suitably resiliently compressible material, such as a polymer. The resiliently compressible member 60 can define an inner cavity 62 through which a distal portion of the drawstring 34 can extend and attach to the more distally positioned inner retainer 36. In some embodiments, the resiliently compressible member 60 can be configured to bias the inner retainer 36 to a first position. For example, the resiliently compressible member 60 can define a longitudinal axis that corresponds to the longitudinal axis of the tether assembly 18. Axial expansion of the resiliently compressible member 60 relative to the longitudinal axis causes it to exert a distal force on the inner retainer 36, thereby moving the inner retainer 36 from a second position to a first position.

[0083] In this way, the resiliently compressible member 60 can act as a spring biasing the internal retainer 36 to a first position. Biasing the internal retainer 36 to the first position can provide one or more advantages, such as allowing a clinician to load the IMD 10 onto the tether head assembly 18 without necessarily requiring the assistance of another clinician. When the tether assembly 12 is in the assembled configuration, for example... Figure 4AAs shown, the resiliently compressible member 60 can be housed within the sheath 40. In this way, the sheath 40 can provide a stop against which the resiliently compressible member 60 can be compressed during the movement of the inner retainer 36 from the first position to the second position.

[0084] Figure 4B The form of the resiliently compressible member 60 shown herein is an example. In other examples, other forms of resiliently compressible members can be used to provide the functions described herein with respect to the resiliently compressible member 60. For example, the resiliently compressible member can be in the form of a coil or a spring. Additionally, the resiliently compressible member can be formed from a variety of materials such as polymers or metals.

[0085] Figure 4C yes Figure 4B A plan view of the distal portion 52 of the inner retainer 36, outlining its contours. (See attached image.) Figure 4C As shown, the distal portion 52 of the inner retainer 36 may define a first portion 70, a second portion 72, and a third portion 74. The first portion 70 may include the distal end of the inner retainer 36 and may have a first thickness. The second portion 72 may be proximal to the first portion 70 and may have a second thickness greater than the first thickness of the first portion 70. The third portion 74 may extend between the first portion 70 and the second portion 72 and may gradually decrease in thickness from the first thickness of the first portion 70 to the second thickness of the second portion 72. In this way, the gradually decreasing thickness of the third portion 74 may define a "slope" surface from the proximal portion 70 toward the second portion 72 and the container 44.

[0086] When the attachment member 14 of the IMD 10 is housed in the container 44 (e.g., when the inner retainer 36 is in the first position), the ramped surface defined by the third portion 74 helps ensure substantially constant physical contact between the attachment member 14 and at least the third portion 74 of the inner retainer 36. Figure 5D The physical contact between the attachment member 14 and the internal retainer 36, achieved through the third part 74, is shown, and further discussion is given regarding the physical contact.

[0087] In some instances, the internal retainer 36 and the attachment member 14 may be conductive. In such instances, ensuring a substantially constant physical contact between the attachment member 14 and the internal retainer 36 during the delivery of the IMD 10 can serve as an electrical connection and / or help reduce electrical noise that might otherwise be caused by intermittent contact between the attachment member 14 and the internal retainer 36. This reduction in electrical noise can help determine whether the IMD 10 is correctly positioned and / or attached relative to the tissue of the heart 1 during electrical testing of the IMD 10 prior to its release from the tether head assembly 18 at the implantation site.

[0088] Figure 4D This illustrates how, when the inner retainer 36 is in its first position, the distal portion 52 of the inner retainer 36 can be received within a recess 58 defined by the distal portion 56 of the outer retainer 38. In some instances, the recess 58 may extend proximally from the distal end 48 of the outer retainer 38 toward the container 44. In some instances, the recess 58 may extend proximally toward the proximal portion 54 of the outer retainer 38 through the container 44. In any such instances, the recess 58 may help provide support for the distal portion 52 of the inner retainer 36, such as by reducing the likelihood of lateral bending of the distal portion 52 during loading of the attachment member 14 of the IMD 10 into the container 44 or during other use of the tether assembly 12. In this way, the recess 58 may help maintain the mechanical integrity and functionality of the tether assembly 12 during one or more uses, thereby contributing to the durability of the tether assembly 12.

[0089] Figure 5A It is a side view of the distal portion of the tether assembly 12, including the tether head assembly 18, combined with the side view of the IMD 10, wherein the tether head assembly 18 and the IMD 10 are not connected. Figure 5B It is the proximal part of the tether head assembly 18 and IMD 10. Figure 5A The cross-sectional view of the highlighted portion, wherein the cross-section is along a plane parallel to the longitudinal axis of the tether head assembly 18 and the longitudinal axis of the IMD 10. Figure 5A The line AA was intercepted. Figure 5C Includes the distal portion of the tether head assembly 18 and the proximal portion of the IMD 10. Figure 5A The cross-sectional view of the highlighted portion, but in which the inner retainer 36 is in the second position and the attachment member 14 is within the container 44 defined by the outer retainer 38. Figure 5D It includes the distal portion of the tether head assembly 18 and the proximal portion of the IMD 10. Figure 5AThe cross-sectional view of the highlighted portion, but in which the attachment member 14 is held by the inner retainer 36 in the first position within the container 44 defined by the outer retainer 38.

[0090] Figure 5A and 5B The disengagement of the IMD 10 from the tether assembly 12 is demonstrated, which may occur before the IMD 10 is attached to the tether assembly 12 or after the IMD 10 has been implanted at the desired tissue site. Specifically, in Figure 5A and 5B In this case, the attachment member 14 of IMD 10 is not housed within the tether head assembly 18 of the tether assembly 12.

[0091] Figure 5B A sheath 40 of the tether head assembly 18, attached to the distal end of the elongated member 20 of the tether assembly 12, is shown. The pull cord 34 extends through the cavity defined by the elongated member 20 and into the cavity 64 defined by the sheath 40. Figure 4B The resiliently compressible member 60, the proximal portion 50 of the inner retainer 36, and the proximal portion 54 of the outer retainer 38 are disposed within a cavity 64, wherein the distal portion 66 of the resiliently compressible member 60 and the proximal portion 50 of the inner retainer 36 are received within a channel 68 defined by the proximal portion 54 of the outer retainer 38. Figure 5C Inside. The drawstring 34 extends through the cavity 62 defined by the resiliently compressible member 60 and connects to the internal retainer 36, for example, being securely housed within the proximal portion 50 of the internal retainer 36. The various components of the delivery system 12 and the tether assembly 18 can be connected using any of a variety of techniques such as welding, crimping, threading, reflowing, bonding, adhesive, or friction fitting.

[0092] The distal portion 52 of the inner retainer 36 extends into the distal portion 56 of the outer retainer 38 to help define the container 44. In the first position shown, the distal portion 52 of the inner retainer 36 also extends into the passage 46 to reduce the size of the passage such that the thickness or depth of the passage is less than the thickness of the attachment member 14 of the IMD 10. In the first position shown, the distal portion 52 of the inner retainer 36 can be positioned within the recess 58 defined by the distal portion 56 of the outer retainer 38 as described herein. In the first position shown, the resiliently compressible member 60 can be in a relaxed state or a lower kinetic energy state.

[0093] like Figure 5BAs shown, the attachment member 14 of the IMD 10 can be included as part of a structure with various features supporting various functions related to the delivery and retrieval of the IMD 10. In the illustrated example, the attachment member 14 is formed within the housing 80 of the IMD 10 and connected to the housing via a shield structure 90. In the illustrated example, the attachment member 14 includes a pin (also referred to as a post) that is welded or otherwise securely attached to the shield structure 90. The attachment member 14 provides an elongated retaining surface spaced from the proximal end 82 of the housing 80 and extending along a length substantially orthogonal to the longitudinal axis of the IMD 10.

[0094] The shield structure 90 may define a cavity with an opening, and the attachment member 14 may span the opening and be exposed at the opening. The attachment member 14 may be welded to the opposite side of the shield structure 90 at either end. The distal portion 56 of the outer retainer 38 may be configured to enter the shield structure 90 or otherwise interact with the shield structure when the attachment member 14 is received within the passage 46 and the container 44. The configuration of the shield structure 90 and the distal portion 56 of the outer retainer 38 may selectively prevent or allow relative movement of the IMD 10 and the tether assembly in multiple directions. It should be understood that the shield structure 90 and the attachment member 14 are provided for illustrative purposes only, and various other attachment members may be configured to attach to the tether assembly as described herein.

[0095] Figure 5C An inner retainer 36 in a second position and an attachment member 14 within a container 44 defined by an outer retainer 38 are shown. The inner retainer 36 can be moved to the second position by a proximal force. This proximal force can be provided by a pull from a drawstring 34 or a thrust on the distal end 65 of the inner retainer 36 as the attachment member 14 is pushed through the passage 46 and into the container 44. Figure 5C As shown, the movement of the inner retainer 36 to the second position has compressed the resiliently compressible member 60, for example, so that the distal portion 66 is no longer positioned within the channel 68 defined by the proximal portion 54 of the outer retainer 38.

[0096] When under this compressed state, the elastically compressible member 60 can be released by expanding in the direction of its longitudinal axis, as... Figure 5B and 5D The higher kinetic energy of the expanded or relaxed state shown in the figure moves the inner retainer 36 from the second position to the second position. Figure 5B and 5D The first position shown in the text. Figure 5DThe attachment member 14 is shown to be held in a first position by an inner retainer 36 within a container 44 defined by an outer retainer 38. The container 44 is configured, for example, in size and shape, to retain the attachment member 14 while allowing the distal portion 52 of the inner retainer 36 to move through the attachment member, for example, through the passage 46. Figure 5D As shown, when the attachment member is positioned within the container 44, for example when the inner retainer 36 is in the first position, at least a third portion 74 of the distal portion 52 of the inner retainer 36 can contact the attachment member 14 of the IMD 10. As described herein, the third portion 74 can secure the attachment member 14 within the container 44 and help ensure a substantially constant physical contact between the attachment member 14 and at least the third portion 74 of the inner retainer 36. The physical contact between the attachment member 14 and the inner retainer 36 ensured by the third portion 74 can provide a substantially constant electrical contact for the conduction of electrical signals from the IMD 10 to the proximal portion of the tether assembly 12, for example, for impedance detection.

[0097] Figure 6A This is an exploded view of the distal portion of another example tether assembly 112, which includes another example tether assembly 118 and a pull cord 134, wherein the outline of the distal portion 152 of the inner retainer 136 of the tether head assembly 118 is depicted. Figure 6B It includes the distal portion 152 of the internal retainer 136 that engages with the distal portion 176 of the draw wire 134. Figure 6A Draw a plan view of the outline. Figure 6C This is a plan view of the distal portion 152 of the inner retainer 136 housed within the outer retainer 38 of the tether head assembly 118. Figure 6D This is a cross-sectional view of the proximal portion of the tether head assembly 118 and the IMD 10, wherein the cross-section is taken along a plane parallel to the longitudinal axis of the tether head assembly and the longitudinal axis of the IMD. Except as noted herein, the tether assembly 112 and the tether head assembly 118 may be related to the above-mentioned... Figures 4A-5D The described tether assembly 12 and tether head assembly 18 are substantially similar. For example, the components of tether assembly 112 and tether head assembly 118, having the same reference numerals as those in tether assembly 12 and tether head assembly 18, can be as described with respect to... Figures 4A-5D The described configuration and functionality are then implemented.

[0098] exist Figures 6A-6D In the example, the internal retainer 136 is related to the above regarding Figures 4A-5DThe described inner retainer 36 is different. Similar to inner retainer 36, inner retainer 136 includes a proximal portion 150 received in a channel defined by the proximal portion 54 of outer retainer 38. Inner retainer 136 also includes a distal portion 152 supported by a defined recess 58. However, the distal portion 152 of inner retainer 136 does not include portions of varying thicknesses, such as similar portions 70, 72, and 74 of the distal portion 52 of inner retainer 36. In some instances, the distal portion 152 defines a substantially constant thickness along its length. Attachment member 14 can apply force to the distal end 65 of inner retainer 136 and move inner retainer 136 to a second position when resiliently compressible member 60 is compressed, thereby allowing attachment member 14 to pass through passage 46 and into container 44. Figure 6D As shown, the inner retainer 136 can, for example, return to a first position in response to longitudinal expansion of the resiliently compressible member 60 to retain the attachment member 14 in the container 44. However, the distal portion 152 may not include, for example, the inclined or elevated surface for contacting the attachment member 14 provided by portion 74 of the distal portion 52 of the inner retainer 36. The distal portion 56 of the outer retainer 38. Similar to the inner retainer 36, when the inner retainer 136 is in the first position and the resiliently compressible member 60 is in its relaxed state, the distal portion 152 of the inner retainer 136 extends into the orifice 42 to reduce the size of the passage 46.

[0099] Figures 6A-6D Different connections between the pull cord 134 and the inner retainer 136 are also shown, followed by the connection between the pull cord 134 and the inner retainer 36. Specifically, the pull cord 134 includes a curved distal portion 176. The proximal portion 150 of the inner retainer 136 defines a notch or other corresponding feature configured to receive the curved distal portion 176. Figure 6D When the pull wire 134 is actuated, the distal portion 176 can bearing the proximal portion 150 to move the internal retainer 136 from a first position to a second position. In some instances, Figures 6A-6D The connection between the draw wire 134 and the internal retainer 136 shown in the figure can, for example, allow some relative movement between these structures in response to bending and length changes of the draw wire 134 during the implantation procedure.

[0100] Figure 7 This is a functional block diagram demonstrating a sample configuration of IMD 10. For example... Figure 7As shown, IMD 10 includes a processing circuitry 220, a sensing circuitry 222, a therapy delivery circuitry 224, a sensor 226, a communication circuitry 228, and a memory 230. In some instances, memory 230 contains computer-readable instructions that, when executed by processing circuitry 220, cause IMD 10 and processing circuitry 220 to perform various functions accorded to IMD 10 and processing circuitry 220 herein. Memory 230 may contain any volatile, non-volatile, magnetic, optical, or electrical medium, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash, or any other digital medium.

[0101] Processing circuitry system 220 may include fixed-function circuitry system and / or programmable processing circuitry system. Processing circuitry system 220 may include any one or more of the following: microprocessor, controller, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or equivalent discrete or analog logic circuitry system. In some instances, processing circuitry system 220 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 systems. The functionality attributed herein to processing circuitry system 220 may be embodied in software, firmware, hardware, or any combination thereof.

[0102] In some instances, the processing circuitry 220 may receive values ​​of multiple cardiac sensing parameters, cardiac therapy parameters (e.g., cardiac pacing parameters), and / or electrode vectors via the communication circuitry 228 (e.g., from an external device). The processing circuitry 220 may store such parameters and / or electrode vectors in the memory 130.

[0103] Therapeutic delivery circuitry 224 and sensing circuitry 222 are electrically coupled to electrode 232, which may correspond to electrodes 86 and 88. Figure 3 and 5A The processing circuitry 220 is configured to control the therapy delivery circuitry 224 to generate an electrotherapy and deliver it to the heart 2 via electrodes 132. The electrotherapy may include, for example, pacing pulses or any other suitable electrical stimulation. The processing circuitry 220 can control the therapy delivery circuitry 224 to deliver the electrical stimulation therapy via electrodes 232 according to one or more therapy parameter values ​​that may be stored in memory 230. In some instances, the therapy delivery circuitry 224 may include capacitors, current sources, and / or regulators.

[0104] Additionally, the processing circuitry 220 is configured to control the sensing circuitry 222 to monitor signals from the electrode 232 in order to monitor the electrical activity of the heart 2. The sensing circuitry 222 may include circuitry for acquiring electrical signals, such as filters, amplifiers, and analog-to-digital circuitry. The electrical signals acquired by the sensing circuitry 222 may include inherent and / or pacing cardiac electrical activity, such as atrial depolarization and / or ventricular depolarization. The sensing circuitry 222 may filter, amplify, and digitize the acquired electrical signals to generate raw digital data. The processing circuitry 220 may receive the digitized data generated by the sensing circuitry 222. In some instances, the processing circuitry 120 may perform various digital signal processing operations on the raw data, such as digital filtering. In some instances, in addition to the sensing circuitry 222, the IMD 10 may optionally include a sensor 226, which, for example, may be one or more pressure sensors and / or one or more accelerometers. The communication circuit system 228 may include any suitable hardware (e.g., an antenna), firmware, software, or any combination thereof for communicating with another device, for example, outside the patient.

[0105] Figure 8 It demonstrates how to use Figures 4A-5D The tether assembly 12 and Figures 6A-6D A flowchart illustrating an example technology for the tethering assembly 112. Although in Figures 4A-5D The tether assembly 12 and tether head assembly 18 are described in the context of Figure 8 The example techniques are provided, but they should not be construed as limiting; rather, they can be applied to various uses. Figures 6A-6D Methods of using tether assembly 112 and tether head assembly 118 or any other tether assembly configured according to the technology of this disclosure.

[0106] Figure 8 Example techniques include attaching the tether head assembly 18 of the tether assembly 12 to the attachment member 14 (240) of the IMD 10. For example, a clinician can hold the tether head assembly 18 with one hand and press the attachment member 14, for example, against the distal end 65 of the inner retainer 36 into a passage 46 defined by the outer member 38, thereby causing the inner retainer 36 to move to a second position as the attachment member 14 moves through the passage 46 into the container 44 and as the resiliently compressible member 60 is compressed. Once the attachment member 14 is housed within the container 44, the clinician can release his or her grip on the IMD 10 to allow the inner retainer 36 to return to the first position by biasing the inner retainer 36 to the first position provided by the resiliently compressible member 60.

[0107] With the attachment member 14 housed within the container 44, the clinician can then position the IMD 10, attached to the tether head assembly 18, at the patient's treatment site (e.g., a treatment site within the heart 1) (242). In some instances, the delivery catheter 9 is advanced, for example, as described above... Figure 2 and 3 When the treatment site is described, the delivery catheter may carry the IMD 10 and the tether assembly 12. In some instances, the clinician may determine whether the IMD 10 is correctly positioned relative to the heart 1 based on impedance signals sensed through the electrical path of one or more components including the IMD 10, attachment member 14, and tether assembly 12 (e.g., the internal retainer 36 of the tether head assembly 18 and / or one or more other components). The clinician may then advance the fixation member 16 into the tissue of the heart 1 to secure the IMD 10 at the implantation site (244).

[0108] Once the positioning and fixation of the IMD 10 relative to the heart 1 tissue are satisfactory, the clinician can detach the attachment member 14 of the IMD 10 from the tether head assembly 18. For example, the clinician can move the tether 34 proximally by applying force to the actuator of the tether handle assembly attached to the proximal end of the tether 34 to move the inner retainer 36 from a first position to a second position (246). With the inner retainer 36 in the second position, the clinician can move the tether assembly 12 proximally to remove the attachment member 14 from the tether head assembly 18 (248). For example, proximal movement of the tether assembly 12 with the inner retainer 36 in the second position allows the attachment member 14 to pass through the passage 46 from the container 44 and exit from the distal end 48 of the outer retainer 38.

[0109] Figure 9A-11J Another example of a tether assembly 250, including a tether handle assembly 252, is shown in the proximal portion. Figure 9A This is a plan view of the rope handle assembly 252, and Figure 9B This is an exploded plan view of the rope handle assembly 252. (See attached image.) Figure 9A As shown, the tether handle assembly 252 can be attached to the proximal end of the elongated member 254 of the tether assembly 250, the elongated member corresponding to and substantially similar to... Figure 3-6DThe elongated member 20 is shown in the diagram. In some instances, the tether handle assembly 252 may be a handle assembly that includes either the tether head assembly 18 or 118. In some such instances, the tether head assembly 18 or 118 may be attached to the elongated body 254 in a manner similar to how the tether head assembly 18 or 118 can be attached to the elongated body 20 as described above. The tether head assembly and tether handle assembly described herein may be used as part of a tether assembly in any suitable combination with each other. Therefore, the example combinations of the described tether head assembly and tether handle assembly are exemplary and should not be construed as limiting.

[0110] The tether handle assembly 252 includes a housing 258. A pull cord (not shown) may extend through an elongated member 254 and may include a proximal end housed within the housing 258 of the tether handle assembly 252. The tether handle assembly 252 may further include a button 260 defining a proximal surface 262. The button 260 may be configured to cause proximal movement of the pull cord when a distal force is applied to the proximal surface 262 of the button 260. Proximal movement of the pull cord may allow the internal retainer 36 or 136 to move from a first position to a second position, for example, to remove the attachment member 14 of the IMD 10 from the tether head assembly 18 or 118 as described herein.

[0111] The housing 258 of the tethered handle assembly 252 may include a shield 264 that extends proximally to the proximal surface 262 of the button 260, such that the proximal surface 262 is recessed within the housing 258. Therefore, the shield 264 can help reduce the likelihood of accidentally applying a distal force to the proximal surface 262, which can help reduce the possibility of the IMD 10 being accidentally deployed during the delivery procedure.

[0112] The tether handle assembly 252 may further include a strain relief member 266 attached to the housing 258 at its distal end 268, defined by the housing 258. The pull cord of the tether assembly 250 may extend through the elongated member 254 and be housed within the strain relief member 266. In addition to providing strain relief for the elongated member 254 and the pull cord when it enters the distal end 268 of the housing 258, the strain relief member 266 may also facilitate sensing of impedance signals or electrical testing of the IMD 10 at the treatment site during delivery.

[0113] In some instances, the strain relief member 266 may be conductive and electrically coupled to a conductive element of the elongated body 254. In such instances, the strain relief member 266 may enable the sensing of impedance signals or other electrical signals sensed through the electrical path of the IMD 10, attachment member 14, internal retainer 36 or 136, tether head assembly 18 or 118, elongated member 254, and strain relief member 266. For example, a clinician may couple a conductive clip or similar connector from an external device to the strain relief member 266 during the implantation procedure to effectively electrically couple the external device to the housing 80 of the IMD 10. A return electrode may be attached to the patient and coupled to the external device to provide a return path.

[0114] As mentioned above Figure 3 Based on the impedance signal sensed through this electrical path, clinicians can determine whether the cup 8 and / or IMD 10 are correctly positioned relative to the tissue 15 of the heart 1 and / or whether the IMD 10 is correctly secured to the tissue by the fixation member 16. In this way, the strain relief member 266 can help clinicians determine whether the IMD 10 is correctly placed at the treatment site.

[0115] like Figure 9B As shown, the interior of housing 258 may define at least a portion of a curved channel 270, which defines a first end 272 and a second end 274. In the illustrated example, the intermediate portion 276 of the curved channel 270 between the first end 272 and the second end 274 may be separately formed and positioned within housing 258 during, for example, assembly of handle assembly 252 for each manufacture of curved channel 270. The tethered handle assembly 252 may further include a force transmitter 278 housed within curved channel 270. In the illustrated example, force transmitter 278 comprises a plurality of balls (e.g., ball bearings) or other similar objects movable through channel 270. However, other suitable objects configured to be housed within and movable through channel 270 may be used as alternatives to or supplements to the plurality of balls.

[0116] The lanyard handle assembly 252 may further include a slidable member 280 housed within the housing 258, such that the channel portion 282 of the slidable member 280 is housed within the channel 270 at a first end 272 of the channel 270. For example... Figure 9BAs shown, the proximal end 286 of the draw wire 284 can extend from the elongated member 254 through the strain relief member 266 and is housed within the housing 258. The proximal end 286 of the draw wire 284 is attached to the sliding member 280. In the example shown, the proximal end 286 of the draw wire 284 is housed within an anchoring member 288, which allows the sliding member 280 to hold the proximal end 286 of the draw wire 284, thereby attaching the proximal end 286 of the draw wire 284 to the sliding member 280.

[0117] Button 260 may include an elongated distal portion 290 housed at a second end 274 within a channel 270. The distal portion 290 of button 260 may be configured to move a force transmitter 278 toward the first end 272 within the channel 270 and contact the channel portion 282 of the sliding member 280. For example, when button 260 moves from a first position to a second position in response to applying a distal force to the proximal surface 262 of the button (e.g., by a clinician pressing the button), the distal portion 290 of button 260 may contact the force transmitter 278 and move it toward the first end 272 through the channel 270. Because the force transmitter 278 contacts the portion 282 of the sliding member 280 housed within the channel 270, the force transmitter 278 applies a proximal force to the channel portion 282 and thus to the sliding member 280. This proximal force causes the sliding member 278 and the pull cord 284 to move proximally. In this way, channel 270 and force transmitter 278 can be configured to convert a distal force applied to the proximal surface 262 of button 260 into a proximal force applied to the sliding member 280 and pull wire 284. In some instances, clinicians may find that applying a distal force (i.e., a push) to button 260 to release IMD10 is more intuitive and / or easier to use than some other handle assembly configurations.

[0118] In some instances, the tethered handle assembly 252 may further include a resiliently compressible member 292, such as a spring, positioned proximal to the housing 258 of the sliding member 280. In some instances, the resiliently compressible member may aid in controlling the movement of the sliding member 280. When the handle assembly 252 is in the assembled configuration, the button 260 may surround at least a proximal portion of the resiliently compressible member 292. Proximal movement of the sliding member 280 may axially compress the resiliently compressible member 292 relative to its longitudinal axis. In some instances, the resiliently compressible member 292 may aid in controlling the proximal movement of the sliding member 280 as it moves proximal within the housing 258. Alternatively or additionally, the resiliently compressible member 292 may be configured to bias the sliding member 280 and / or the button 260 to their respective first positions, such as when the button 260 is not pushed distally inward relative to the housing 258, as per [reference to...]. Figure 10A-10D As shown and described. Therefore, when the physician releases button 260, the pull cord 284 can be moved distally via the resilient compressible member 292 to help return the tether head assembly 18 or 118 to a closed configuration, such as, in some instances, returning the internal retainer 36 or 136 to a first position. Some example tether assemblies may include both a resilient compressible member, such as resilient compressible member 292, in the handle assembly and a resilient compressible member, such as resilient compressible member 60, in the head assembly, while other tether assemblies may include only one of the resilient compressible members to provide, for example, the function of returning the tether head assembly to a closed configuration, such as returning the internal retainer to a first position.

[0119] In some instances, such as Figure 9B As shown, housing 258 may include a removable cover portion 296 that facilitates the manufacture of tethered handle assembly 252. Tethered handle assembly 252 may further include a resilient stretch band 294, which may be configured to be positioned over the distal portions of housing 258 and cover 296 to help hold the components of handle assembly 252 in place. Figure 9A The assembly configuration shown in the image.

[0120] Figure 10A-10D yes Figure 9A and 9B A side view of the tethered handle assembly 252, with a portion of the housing 258 removed. The side view shows the force transmitter 278, the sliding member 280, and the pull cord 284 responding to the button 260 from a first position 300. Figure 10A Move to the second position 302 ( Figure 10DThe button 260 can be moved to a first position 300, which may be its "original" or uncompressed position. The second position 302 may be a compressed or recessed position of the button 260. The resiliently compressible member 292 may bias the button 260 to the first position 300.

[0121] like Figure 10B-10D As shown, when button 260 is pushed inward into cover 264 with a distal force in the direction of arrow 304, the distal portion 290 of button 260 moves distally within channel 270 in the direction of arrow 304. As the distal portion 290 moves distally within channel 270, it directs force transmitter 278 toward the first end 272 within the channel. Figure 9B The force transmitter 278 transmits the force from the button 260 toward the distal side to the force in the direction of arrow 306 toward the proximal side of the channel portion 282 of the sliding member 280. In response to the force toward the proximal side, the sliding member 280 and the attached pull cord 284 can move proximally in the direction of arrow 306, which allows the tether head member 18 or 118 to open at the distal end of the tether assembly as described herein.

[0122] like Figure 10B As shown, housing 258 and button 260 may include features configured to interact, for example, be adjacent, when button 260 is in the second position 302. Such features can prevent button 260 from moving further distally beyond the second position 302. In the example shown, housing 258 defines an inner shoulder 308, and button 260 includes a distal protrusion 310.

[0123] As button 260 moves from first position 300 to second position 302 in the distal direction 304 and the sliding member 280 moves correspondingly in the proximal direction 306, the resiliently compressible member 292 compresses between button 260 and the sliding member 280, thereby storing potential energy. When the physician releases button 260, the resiliently compressible member 292 can expand longitudinally, thereby releasing the stored energy and causing button 260 and the sliding member 280 to move in directions 306 and 304 respectively, until button 260 is once again in the first position 300. As the sliding member 280 moves distally in direction 304, the pull cord 284 can also move distally to help return the tether head assembly 18 or 118 to a closed configuration, for example, in some instances, returning the internal retainer 36 or 136 to the first position.

[0124] Figure 11A-11J yes Figure 9A and 9BA plan view of the tether assembly 250 and the tether handle assembly 252, illustrating example techniques for assembling the tether handle assembly 252. (As shown) Figure 11A As shown, the guy wire 284 extends from the proximal end of the elongated member 254 and passes through the strain relief member 266 at the proximal end of the elongated member 254. An anchoring member 288 may be formed on or attached to the proximal end 286 of the guy wire 284.

[0125] like Figure 11B As shown, housing 258 may define a container 320 configured to receive strain relief member 266 and a channel 322 configured to receive pull wire 284. Anchor member 288 may be positioned at the end of channel 322 opposite to strain relief member 266. This configuration, including securing strain relief member 266 within container 320 of housing 258, can provide strain relief for the connection of elongated member 254 to handle assembly 252.

[0126] Figure 11C The insertion of the middle section 276 is shown to complete the curved channel 270, which also closes the channel 322. Figure 11D A sliding member 280 inserted into the housing 258 is shown. The sliding member 280 may define features (not shown) configured to receive the anchoring member 288, thereby connecting the pull wire 284 to the sliding member 280.

[0127] Figure 11E A resiliently compressible member 292 inserted into the housing 258 is shown, and Figure 11F A button 260 inserted into housing 258 is shown. The sliding member 280 and button 260 may include features for holding the resiliently compressible member 292 therebetween. Figure 11F The distal portion 290 of the button 260 inserted at the second end 274 of the channel 270 is also shown.

[0128] Figure 11G A force transmitter 278 is shown inserted into a channel 270 between the distal portion 290 of the button 260 and the channel portion 282 of the sliding member 280. Figure 11H A removable cover 296 attached to housing 258 is shown, and Figure 11I A resilient stretch band 294 is shown, which is placed on the distal portion of the housing 258 and the cover 296 to help keep the components of the tether handle assembly 252 in the assembled configuration. Figure 11I and 11JThe housing 258 also demonstrates features that can define the usability of the handle assembly 252, such as recesses 324 and ridges 326, which can help physicians orient and grip the tethered handle assembly 252.

[0129] Figures 12A-12E This is a plan view of another example tether handle assembly 352. The tether handle assembly 352 can be used with... Figure 9A-11J The described tether handle assembly 252 is substantially similar. For example, components with the same reference numerals as tether handle assembly 252 can be like those described above. Figure 9A-11J Configure and function as described.

[0130] Unlike the tether handle assembly 252, the tether handle assembly 352 includes a cover 354 for the button 260. Figure 12E The housing 358 of the tethered handle assembly 352, such as the shield portion 364 of the housing, may define a recess 370 configured to allow a user's finger to approach a tab 372 formed on the cover 354 to move the cover 354 away from the button 260. The cover 354 may be included on the tethered handle assembly 352 to reduce the likelihood of accidental pressing of the button 260 and IMD 10 deployment during implantation procedures using the tethered handle assembly 352 for IMD 10.

[0131] The 376 strap allows the cover 354 to be connected to the collar 374. For example, as... Figure 12D As shown, the collar 374 and the strap 376 can be configured to keep the cover 354 attached to the tether handle assembly 352 as the cover 354 moves away from the button 260. For example, as Figure 12D and 12E As shown, the strap 376 can be configured to space the cover 354 from the proximal opening of the shield portion 364 to facilitate user access to the proximal surface 262 of the button 260 when the cover 354 is moved. The cover 354, the collar 374, and the strap 376 can be formed of any material such as a polymer, and can be formed from a single piece of material, for example, molded as a single piece of material. The shield portion 364 and / or other portions of the housing 358 can be configured with corresponding features for receiving the collar 374 and the strap 376, for example, to secure them to the lanyard handle assembly 352 and to provide a substantially uniform outer surface for the lanyard handle assembly 352.

[0132] like Figure 12D and 12E As shown, the cover 354 may include a plug portion 378 with a reduced diameter. (As illustrated...) Figure 12EAs shown, the proximal opening of the cover portion 364 can define a shelf 380 with an enlarged diameter configured to receive the plug portion 378. The plug portion 378 and the shelf 380 can be configured to interact to secure the cover 354 within the proximal opening of the cover portion 364, for example by friction engagement, threading, or other attachment mechanisms.

[0133] Figure 13A and 13B It is a plan view of the proximal end of another example tether handle assembly 452, which is connected to the proximal end of the elongated member 454, and another example tether assembly 412. Figure 13C This is an exploded plan view of the rope handle assembly 452. Figure 13D and 13E This is a plan view of the tether handle assembly 452, in which a portion of the housing 458 of the tether handle assembly 452 is removed to show an example arrangement, interaction, and movement of the components of the tether handle assembly 452 during use.

[0134] The elongated member 454 of the tether assembly 412 can correspond to and is substantially similar to Figure 3-6D The elongated member 20 is shown in the diagram. In some instances, the tether handle assembly 452 may be a handle assembly that includes either the tether head assembly 18 or 118. In some such instances, the tether head assembly 18 or 118 may be attached to the elongated body 454 in a manner similar to how the tether head assembly 18 or 118 can be attached to the elongated body 20 as described above. The tether head assembly and tether handle assembly described herein may be used as part of a tether assembly in any suitable combination with each other. Therefore, the example combinations of the described tether head assembly and tether handle assembly are exemplary and should not be construed as limiting.

[0135] exist Figure 13C In the example shown, housing 458 comprises two housing portions 458A and 458B. Housing portions 458A and 458B may be press-fitted together or otherwise connected during the assembly of the tethered handle assembly 452 to form housing 458, for example, after the components of the tethered handle assembly 452 described herein have been suitably arranged. In some examples, housing portions 458A and 458B may be molded components of plastic or another polymer.

[0136] 484 pull wires Figure 13CThe tether handle assembly 452 may extend through the elongated member 454 and may include a proximal end 486 housed within a housing 458 of the tether handle assembly 452. The tether handle assembly 452 may further include a button 460 defining a proximal surface 462 and configured to cause proximal movement of the pull cord 484 when a distal force is applied to the proximal surface 462 of the button 460. Proximal movement of the pull cord 484 may allow the internal retainer 36 or 136 to move from a first position to a second position, for example, as described herein. Figure 4A-6D The described method involves removing the attachment member 14 of the IMD 10 from the tether head assembly 18 or 118.

[0137] The tether handle assembly 452 may further include a strain relief member 466 attached to the distal end of the housing 458. An elongated member 454 may be attached to the strain relief member 466, and a pull wire 484 may be housed within the strain relief member 466. In addition to providing strain relief for the elongated member 454 and the pull wire 484 when the elongated member is attached to the housing 458 and the pull wire is inside the housing, the strain relief member 466 may also be conductive and facilitate sensing of impedance signals or electrical testing of the IMD 10 at the treatment site during delivery, as described above regarding the strain relief member 266.

[0138] like Figure 13C As shown, button 460 includes a bracket 470 within a housing defining internal teeth 472, the internal teeth being configured to interact with corresponding teeth of gears 474A and 474B (collectively, "gears 474"). Button 460 may be machined and / or molded. The tether handle assembly 452 further includes a slidable member 480, the slidable member including teeth 482 on opposite sides of the slidable member. The teeth 482 of the slidable member 480 are configured to interact with the teeth of gear 474. The slidable member 480 defines a longitudinal cavity through which the distal end 486 of the pull cable 484 extends, and a distal portion of a sleeve 488 can be inserted into the longitudinal cavity. The sleeve 488 can be used to attach the pull cable 484 to the slidable member 480 by defining the cavity to receive the proximal end 486 of the pull cable 484. The proximal end 486 of the guy wire 484 can be achieved by welding, crimping, capping, gluing, and / or using anchoring components (e.g., Figure 9B Anchoring member 288 is used as an example to fix it to sleeve 488.

[0139] The tether handle assembly 452 further includes resiliently compressible members 492A, 492B, and 492C (collectively referred to as "resiliently compressible member 492") within the housing 458, such as a spring. A longitudinal cavity defined by the sliding member 480 houses the resiliently compressible member 492C, which inhibits proximal movement of the pull cord 484 when the button 460 is pushed distally.

[0140] Figure 13D and 13E This is a side view of the lanyard handle assembly 452, with the housing portion 458A removed. The side view shows the bracket 470, gear 474, sliding member 480, and pull cable 484 in response to button 460 from a first position. Figure 13D Move to the second position. Figure 13E And move. Figure 13D The first position shown can be the "original" or uncompressed position of button 460. Figure 13E The second position shown can be a compressed or recessed position of button 460. Resiliently compressible members 492A and 492B can bias button 460 to the first position.

[0141] like Figure 13D and 13E As shown, when button 460 is pushed inward with a distal force in the direction of arrow 494, bracket 470 moves distally within housing 458 in the direction of arrow 494. As bracket 470 moves distally, teeth 472 cause gear 474 to rotate. As gear 474 rotates against teeth 482 of sliding member 480, sliding member 480 moves proximally in the direction of arrow 496, and pushes pull cable 484 connected to sliding member 480 proximally in the direction of arrow 496. In this way, gear 474 transfers the distal force from button 460 to a proximal force in the direction of arrow 496, in response to which pull cable 484 can move proximally in the direction of arrow 496, which allows tether head member 18 or 118 to open at the distal end of tether assembly 412 in the manner described herein.

[0142] At button 460 in the distal direction 494 from the first position ( Figure 13D Move to the second position. Figure 13EWhen the button 460 is released, the resiliently compressible members 492A and 492B compress between the button 460 and the features of the housing 458, thereby storing potential energy. When the physician releases the button 460, the resiliently compressible members 492A and 492B can expand longitudinally, thereby releasing the stored energy and causing the button 460 and the sliding member 480 to move in directions 496 and 494 respectively, until the button 460 is once again in the first position. As the sliding member 480 moves distally in direction 494, the pull cord 484 can also move distally to help return the tether head assembly 18 or 118 to a closed configuration, for example, in some instances, returning the internal retainer 36 or 136 to the first position.

[0143] Figure 14 This is a flowchart illustrating an example technique for using a tether assembly, the tether assembly comprising, as described above... Figure 9A-13E The described tether handle assembly and about Figure 4A-6D The described tether head assembly. Although in context... Figures 4A-5D 18 and rope head assembly Figure 9A-11J The tether handle assembly 252 is described in Figure 14 The example techniques described herein are not intended to be limiting, but rather can be applied to the use of... Figures 6A-6D Rope head assembly 118 Figures 12A-12E Methods for configuring handle assemblies 352 and 452 or any other tether head assembly or tether handle assembly according to the technology disclosed herein.

[0144] and Figure 8 Similar examples of techniques, Figure 14 An example technique involves positioning the IMD 10, attached to the tether head assembly 18, at the patient's treatment site (e.g., within the heart 1) (242), with the attachment member 14 housed within the container 44. In some instances, a clinician can determine whether the IMD 10 is correctly positioned relative to the heart 1 based on impedance signals sensed through the electrical path of the IMD 10, the attachment member 14, the tether head assembly 18, the elongated member, and the strain relief member 266. The clinician can then advance the fixation member 16 into the tissue of the heart 1 to secure the IMD 10 at the implantation site (244).

[0145] Once the location and fixation of the IMD 10 relative to the tissue of the heart 1 are satisfactory, the clinician can detach the attachment member 14 of the IMD 10 from the tether head assembly 18. Figure 14In one example, the clinician pushes the proximal surface 262 (500) of the button 260 of the tether handle assembly 252 distally. The tether handle assembly 252 converts the distal force into a proximal force, causing the pull cable 282 to move proximally and opening the tether head assembly 18 (502). For example, the distal portion 290 of the handle 260 can move distally in the channel 270 and the force transmitter 278 passes through the channel 270 against the channel portion 282 of the sliding member 280, which can cause the sliding member 280 to move in the proximal direction. The pull cable 284 connected to the sliding member 280 thus moves in the proximal direction.

[0146] In other instances, distal movement of the bracket 470 of button 460 causes gear 474 to rotate. Rotation of gear 474 causes slidable member 480 to which pull cable 484 is attached to move proximally. In either case, with tether head assembly 18 open, the clinician can move tether assembly 12 proximally to remove attachment member 14 from tether head assembly 18 (248).

[0147] Figure 15A This is a side view of another example tether assembly 550, which includes another example tether handle assembly 552. Figure 15B This is an exploded plan view of the tether assembly 550 and the tether handle assembly 552. Figure 15C-15E This is a perspective view of the tether handle assembly 552, in which part 596 of the housing 558 has been removed. The perspective view shows the different positions of the locking member 570 and the plunger 560 of the tether handle assembly 552 during use.

[0148] like Figure 15A As shown, the tether handle assembly 552 can be coupled to the proximal end of the elongated member 554 of the tether assembly 550, the elongated member corresponding to and substantially similar to... Figure 3-6D The elongated member 20 is shown in the diagram. In some instances, the tether handle assembly 552 may be a tether handle assembly that includes either tether head assembly 18 or 118. In some such instances, tether head assembly 18 or 118 may be attached to the elongated body 554 in a manner similar to how tether head assembly 18 or 118 can be attached to the elongated body 20 as described above. The tether head assembly and tether handle assembly described herein may be used as part of a tether assembly in any suitable combination with each other. Therefore, the example combinations of tether head assembly and tether handle assembly described herein are exemplary and should not be construed as limiting.

[0149] The tether handle assembly 552 includes a housing 558. A pull cable 584 may extend through the elongated member 554 and may include a proximal end housed within the housing 558 of the tether handle assembly 552. The tether handle assembly 552 may further include a plunger 560 configured to cause proximal movement of the pull cable when a user pulls it. Proximal movement of the pull cable may allow an internal retainer 36 or 136 to move from a first position to a second position, for example, as per [reference to...]. Figure 4A-6D The described method involves removing the attachment member 14 of the IMD 10 from the tether head assembly 18 or 118.

[0150] The tether handle assembly 552 may be further included at the distal end of the housing 558, attached to the housing 558 as a strain relief member 566. An elongated member 554 may be attached to the strain relief member 566, and a drawstring 584 may be housed within the strain relief member 566. In addition to providing strain relief for the elongated member 554 and the drawstring 584 when the elongated member is attached to the housing 558 and the drawstring is inside the housing, the strain relief member 566 is also conductive and can facilitate sensing of impedance signals or electrical testing of the IMD 10 at the treatment site during delivery, as described herein with respect to strain relief member 266.

[0151] In the example shown, housing 558 includes a removable cover portion 596 that facilitates the manufacture of handle assembly 552. Handle assembly 552 may further include a resilient stretch band 594, which can be configured to be positioned over the distal portions of housing 558 and cover 596 to help hold the tethered handle assembly 552 in place. Figure 15A The assembly configuration shown in the image.

[0152] like Figure 15B As shown, the tethered handle assembly 552 includes a locking member 570. The locking member 570 includes opposing buttons 572A and 572B (collectively referred to as "buttons 572"). The locking member 570 also defines a keyhole 574. The tethered handle assembly 552 further includes a slidable member 576, which includes a protrusion 578. The slidable member 576 can slide through the internal channel defined by the locking member 570, provided that the protrusion 578 is aligned with the keyhole 574 defined by the locking member 570. Figure 15BAs shown, the proximal end 586 of the pull wire 584 extends from the elongated member 554 through the strain relief member 566 and is housed within the housing 558. The proximal end 586 of the pull wire 584 is attached to the sliding member 576. In the example shown, the proximal end 586 of the pull wire 584 is housed within an anchoring member 588, which holds the proximal end 586 in place of the sliding member 576, thereby attaching the pull wire 584 to the sliding member 576.

[0153] The plunger 560 may include a plug 562 housed within a collar 564. The collar 564 defines an internal passage configured to house a proximal portion of the sliding member 576 containing a bayonet lock 580. The plug 562 may be inserted into the internal passage of the collar 564 between the bayonet locks 580 to push the bayonet locks outward and attach the plunger 560 to the sliding member 576.

[0154] In some instances, the tethered handle assembly 552 may further include a resiliently compressible member 592, such as a spring, between the inner surface of a housing 558 located at one end and the enlarged diameter portion 582 of a sliding member 576 at the opposite end. Proximal movement of the sliding member 576 can axially compress the resiliently compressible member 592 relative to its longitudinal axis. In some instances, the resiliently compressible member 592 can help control the proximal movement of the sliding member 576 in response to a user pulling the plunger 560. Alternatively or additionally, the resiliently compressible member 592 may be configured to bias the sliding member 576 and / or the plunger 560 to their respective first positions, such as their position before the plunger 560 is pulled. Therefore, when the physician releases the plunger 560, the pull cord 584 can be moved distally via the resiliently compressible member 592 to help return the tether head assembly 18 or 118 to a closed configuration, such as, in some instances, returning the internal retainer 36 or 136 to the first position.

[0155] Figure 15C-15E This is a perspective view of the tether handle assembly 552, in which part 596 of the housing 558 has been removed. The perspective view shows the different positions of the locking member 570 and the plunger 560 of the tether handle assembly 552 during use. Figure 15C The image shows both the locking member 570 and the plunger 560 in their first or "original" positions. In the first position, the protrusion 578 of the sliding member 576 is not aligned with the keyhole 574 of the locking member 570. Therefore, the plunger 560 is prevented from being pulled distally to its second position.

[0156] Figure 15DThe locking member 570 is shown in its second position, such that the protrusion 578 of the sliding member 576 is not aligned with the keyhole 574 of the locking member 570. The user can move the locking member 570 to the second position by pressing button 572A of the locking member 570 to move the locking member 570 laterally to the longitudinal axis of the tether handle assembly 552. For example, after unfolding the IMD 10, the user can move the locking member 570 back to the first position by pressing button 572B. It is noteworthy that in both the first and second positions of the locking member 570, the user has easier access to button 572B than button 572A, for example, to prevent accidental unlocking and IMD unfolding.

[0157] Figure 15E The image shows locking member 570 in its second position and plunger 560 pulled to its second position. Pulling plunger 560 to its second position moves pull cord 584 proximally and compresses resilient compressible member 592, thereby storing potential energy. When the physician releases plunger 560, resilient compressible member 592 can expand longitudinally, releasing the stored energy and moving plunger 560 and sliding member 576 distally. As sliding member 576 moves distally, pull cord 584 can also move distally to help return tether head assembly 18 or 118 to a closed configuration, for example, in some instances, returning internal retainer 36 or 136 to the first position.

[0158] Figure 16A This is an exploded plan view of another example tether handle assembly 652. Figure 16B This is a cross-sectional view of the tether handle assembly 652. Except as noted herein, the tether handle assembly 652 may be substantially similar to the above description of... Figures 15A-15E The described tether handle assembly 552. For example, the components of the tether handle assembly 652, which have the same reference numerals as the components in the tether handle assembly 552, can be as described regarding... Figures 15A-15E The described configuration and functionality are then implemented.

[0159] The plunger 660 differs from plunger 560 in that a collar 664 defines an orifice 665. A removable housing portion 696 and a sliding member 676 also define orifices 697 and 678, respectively. Orifices 697, 665, and 678 are aligned to define a passage for receiving a lower portion of the locking member 670 of the tethered handle assembly 652 within the housing 558. The locking member 670 includes a lower post 674 retractable within a longitudinal cavity defined by the resiliently compressible member 675, which biases the locking member 670 into a locked position. The locking member 670 further defines an inlet 672 that serves as a keyway for the locking member 670. When the locking member 670 is pressed down into the unlocked position, thereby compressing the resiliently compressible member 675, the inlet 672 aligns with the distal edge 667 of the orifice 665 defined by the collar 664. The alignment of inlet 672 and distal edge 667 allows the plunger 660 to be pulled proximally. Figure 16B The locking member 670 is shown in the unlocked position, wherein the inlet 672 and the distal edge 667 are misaligned, and the plunger 670 is prevented from being pulled proximally, for example, to open the tether head member and release the IMD.

[0160] Figure 17A This is an exploded plan view of another example tether handle assembly 752. Figure 17B This is a cross-sectional view of the rope handle assembly 752. Figure 17C This is a plan view of the collar portion 764 of the plunger 760 of the tether handle assembly 752. Except as noted herein, the tether handle assembly 752 can be substantially similar to the above description regarding... Figures 15A-15E The described tether handle assembly 552. For example, the components of the tether handle assembly 752, which have the same reference numerals as the components in the tether handle assembly 552, can be as described with respect to... Figures 15A-15E The described configuration and functionality are then implemented.

[0161] The plunger 760 differs from plunger 560 in that the collar 764 includes a cantilever locking mechanism 770. Additionally, the housing 758 defines an orifice 759 configured to receive the button portion 774 of the locking mechanism 770 when in the locked position. The button portion 774 is connected to the collar 764 via an arm portion 772 that biases the button portion 774 into the locked position, such as... Figure 17B As shown in the diagram. When the button portion 774 is housed in the aperture 759 of the housing 758, it prevents the user from pulling the plunger 760 proximally and releasing the IMD 10. The user can press the button portion 774 into the housing 758 to unlock the cantilever locking mechanism 770 and allow the user to pull the plunger 760 proximally (thereby pulling the pull cable 784) and release the IMD 10.

[0162] The following examples illustrate the techniques described in this article.

[0163] Example 1: A tether assembly for a medical device delivery system, the tether assembly comprising: a pull cord defining a proximal end and a distal end; and a tether head assembly. The tether head assembly includes: an inner retainer including a proximal portion and a distal portion, wherein the inner retainer is coupled to the distal end of the pull cord and extends distally from the distal end of the pull cord; and an outer retainer including a channel defined as the proximal portion and the distal portion, the proximal portion receiving the inner retainer, and the distal portion defining an orifice. The orifice includes: a container configured to receive an attachment member of a medical device; a passage extending proximally from a distal end defined by the outer retainer to the container, wherein the passage is narrower than the container; and a groove extending proximally from the distal end of the outer retainer to at least the container, wherein the depth of the groove is less than the thickness of the distal portion of the inner retainer, wherein the inner retainer is movable between a first position and a second position, in which the distal portion of the inner retainer is partially received in the groove and extends into the passage, thereby narrowing the passage, and in the second position, the distal portion of the inner retainer is positioned proximally to the passage.

[0164] Example 2: The tether assembly according to Example 1, wherein the size of the passage is set to receive the attachment member of the medical device when the inner retainer is in the second position, and wherein the size of the passage is set to prevent the attachment member from passing through when the inner retainer is in the first position.

[0165] Example 3: The tether assembly according to Example 2, wherein the dimensions of the passage are set to retain the attachment member of the medical device in the container when the attachment member is housed within the container and the internal retainer is in the first position.

[0166] Example 4: A tether assembly according to any one of Examples 1 to 3, wherein the distal portion of the inner retainer comprises: a first portion, the first portion including the distal end of the inner retainer, the first portion having a first thickness; a second portion, the second portion being located proximal to the first portion, the second portion having a second thickness greater than the first thickness; and a third portion, the third portion extending between the first portion and the second portion, the third portion gradually decreasing in thickness from the first thickness to the second thickness.

[0167] Example 5: The tether assembly according to Example 4, wherein at least the third portion of the internal retainer is configured to contact the attachment member of the medical device when the internal retainer is in the first position.

[0168] Example 6: A tether assembly according to any one of Examples 1 to 5, wherein the internal retainer and the attachment member of the medical device are conductive.

[0169] Example 7: A tether assembly according to any one of Examples 1 to 6, wherein the inner retainer is configured to move from the first position to the second position in response to a proximal movement of the pull cord relative to the outer retainer.

[0170] Example 8: A tether assembly according to any one of Examples 1 to 7, wherein the internal retainer is configured to move from the first position to the second position in response to a force applied to the internal retainer by the attachment member of the medical device.

[0171] Example 9: The tether assembly according to Example 8 further includes a tether handle assembly attached to the proximal end of the pull line, wherein the tether handle assembly includes an actuator configured to cause movement of the proximal side of the pull line.

[0172] Example 10: A tether assembly according to Example 9, wherein the tether handle assembly is configured such that the pull line moves proximally in response to a distal force applied to the actuator and moves distally in response to removing the distal force from the actuator.

[0173] Example 11: A tether assembly according to any one of Examples 8 to 10, further comprising an elongated body defining a proximal end, a distal end, and an inner cavity, wherein a first portion of the pull cord is received within the elongated body.

[0174] Example 12: The tether assembly according to Example 11, wherein the tether head assembly further includes a resiliently compressible member defining an inner cavity, wherein a second portion of the pull cord is received within the inner cavity defined by the resiliently compressible member, such that the resiliently compressible member is positioned proximal to the inner retainer.

[0175] Example 13: The tether assembly according to Example 12, wherein the resiliently compressible member defines a longitudinal axis, and wherein the internal retainer is configured to move from the second position to the first position in response to axial expansion of the resiliently compressible member relative to the longitudinal axis.

[0176] Example 14: A tether assembly according to Example 12 or 13, wherein the tether head assembly further includes a sheath attached to the distal end of the elongated body, wherein the resiliently compressible member, the proximal portion of the inner retainer, and the proximal portion of the outer retainer are housed within the sheath.

[0177] Example 15: A tether assembly according to any one of Examples 12 to 14, wherein the resiliently compressible member is configured to apply a distal force to the inner retainer, the distal force causing the inner retainer to bias to the first position.

[0178] Example 16: A tether assembly according to any one of Examples 12 to 15, wherein the resiliently compressible member comprises a polymer material.

[0179] Example 17: A tether assembly according to Example 16, wherein the tether handle assembly is attached to the proximal end of the pull line at the proximal end of the elongated body, and wherein the tether handle assembly is configured to cause the proximal movement of the pull line by converting a force applied by a user toward the actuator toward the distal side into the proximal movement of the pull line.

[0180] Example 18: A method for using a tether assembly in a medical device delivery system, the method comprising: positioning the tether head assembly of the tether assembly at a treatment site of a patient using an attachment member of the medical device housed within a container of the tether head assembly, the tether head assembly being configured to releasably retain the attachment member of the medical device. The tether head assembly includes: an inner retainer including a proximal portion and a distal portion, wherein the inner retainer is coupled to and extends distally from the distal end of a drawstring of the tether assembly; and an outer retainer including a portion defining a proximal portion and a distal portion, the proximal portion defining a channel for receiving the inner retainer, and the distal portion defining an orifice. The orifice includes a container configured to receive the attachment member of the medical device; a passage extending proximally from the distal end of the outer retainer to the container, wherein the passage is narrower than the container; and a groove extending proximally from the distal end of the outer retainer to at least the container, wherein the depth of the groove is less than the thickness of the distal portion of the inner retainer. Positioning the tether head assembly includes positioning the tether head assembly having the inner retainer in a first position, in which the distal portion of the inner retainer is partially received in the groove and extends into the passage, thereby narrowing the passage, wherein the size of the passage is set to prevent the attachment member from passing through when the inner retainer is in the first position. The method further includes applying a force to an actuator of the tether assembly to cause proximal movement of the pull cord, the proximal movement of the pull cord causing the inner retainer to move from a first position to a second position, in which the distal portion of the inner retainer is positioned proximal to the passage, wherein the passage is sized to receive the attachment member of the medical device when the inner retainer is in the second position, thereby allowing the attachment member of the medical device to pass through the passage from the container; and using the inner retainer in the second position to move the tether assembly proximal to remove the attachment member of the medical device from the tether head assembly, thereby delivering the medical device to the treatment site.

[0181] Example 19: The method according to Example 18 further includes: pressing the attachment member of the medical device against the distal end of the inner retainer between positioning the tether head assembly to move the inner retainer from the first position to the second position, thereby allowing the attachment member of the medical device to pass through the passage and enter the container defined by the outer retainer.

[0182] Example 20: The method according to Example 18 or 19, wherein the internal retainer and the attachment member of the medical device are conductive, the method further comprising: determining whether to apply the force to the actuator based on an impedance signal sensed through an electrical path including the medical device, the attachment member and the internal retainer.

[0183] Example 21: The method according to any one of Examples 18 to 20, wherein the tether handle assembly of the tether assembly includes a housing defining a proximal end and a distal end, wherein the actuator includes a button defining a proximal surface, the proximal surface being distal to the proximal end of the housing when the button is in the first position, and wherein applying the force to the actuator includes applying a force toward the distal side to the proximal surface.

[0184] Example 22: The method according to any one of Examples 18 to 20, wherein the tether handle assembly of the tether assembly includes a locking member, and the method further includes moving the locking member from a first position to a second position, wherein in the first position the locking member restricts the actuation of the actuator, and in the second position the locking member does not restrict the actuation of the actuator.

[0185] Various aspects of this disclosure have been described. These and other aspects are within the scope of the following claims.

Claims

1. A tether assembly for a medical device delivery system, the tether assembly comprising: A drawstring, wherein the drawstring defines a proximal end and a distal end; as well as The tether head assembly includes: An internal retainer, the internal retainer including a proximal portion and a distal portion, wherein the internal retainer is coupled to the distal end of the pull wire and extends distally from the distal end of the pull wire; An external retainer including a proximal portion and a distal portion, the proximal portion defining a channel configured to receive the internal retainer, and the distal portion defining an orifice including: A container configured to house an attachment member of a medical device; A passageway extending proximally from the distal end defined by the external retainer to the container, wherein the passageway is narrower than the container; and A groove, defined by a distal portion of the outer retainer and extending proximally from the distal end of the outer retainer to the container, wherein the depth of the groove is less than the thickness of the distal portion of the inner retainer. The internal retainer is movable between a first position and a second position, in the first position, the distal portion of the internal retainer is partially received in the groove and extends into the passage, thereby narrowing the passage, and in the second position, the distal portion of the internal retainer is positioned proximal to the passage.

2. The tether assembly of claim 1, wherein the size of the passage is configured to receive the attachment member of the medical device when the inner retainer is in the second position, and wherein the size of the passage is configured to prevent the attachment member from passing through when the inner retainer is in the first position.

3. The tether assembly of claim 2, wherein the size of the passage is configured to retain the attachment member of the medical device within the container when the attachment member is housed within the container and the internal retainer is in the first position.

4. The tether assembly according to any one of claims 1 to 3, wherein the distal portion of the inner retainer comprises: A first portion, the first portion including the distal end of the internal retainer, the first portion having a first thickness; The second part is located near the first part and has a second thickness greater than the first thickness. as well as The third part extends between the first part and the second part, and the thickness of the third part gradually decreases from the first thickness to the second thickness.

5. The tether assembly of claim 4, wherein at least the third portion of the internal retainer is configured to contact the attachment member of the medical device when the internal retainer is in the first position.

6. The tether assembly according to any one of claims 1 to 3, wherein the internal retainer and the attachment member of the medical device are conductive.

7. The tether assembly according to any one of claims 1 to 3, wherein the inner retainer is configured to move from the first position to the second position in response to proximal movement of the pull cord relative to the outer retainer.

8. The tether assembly according to any one of claims 1 to 3, wherein the inner retainer is configured to move from the first position to the second position in response to a force applied to the inner retainer by the attachment member of the medical device.

9. The tether assembly of claim 8, further comprising a tether handle assembly attached to the proximal end of the pull line, wherein the tether handle assembly includes an actuator configured to cause movement of the proximal side of the pull line.

10. The tether assembly of claim 9, wherein the tether handle assembly is configured such that the pull line moves proximally in response to a distal force applied to the actuator and moves distally in response to removing the distal force from the actuator.

11. The tether assembly of claim 10, further comprising an elongated body defining a proximal end, a distal end, and an inner cavity, wherein a first portion of the pull cord is received within the elongated body.

12. The tether assembly of claim 11, wherein the tether head assembly further includes a resiliently compressible member defining an inner cavity, wherein a second portion of the pull cord is received within the inner cavity defined by the resiliently compressible member, such that the resiliently compressible member is positioned proximal to the inner retainer.

13. The tether assembly of claim 12, wherein the resiliently compressible member defines a longitudinal axis, and wherein the internal retainer is configured to move from the second position to the first position in response to axial expansion of the resiliently compressible member relative to the longitudinal axis.

14. The tether assembly of claim 12 or 13, wherein the tether head assembly further includes a sheath attached to the distal end of the elongated body, wherein the resiliently compressible member, the proximal portion of the inner retainer, and the proximal portion of the outer retainer are housed within the sheath.

15. The tether assembly of claim 12 or 13, wherein the resiliently compressible member is configured to apply a distal force to the inner retainer, the distal force biasing the inner retainer to the first position.

16. The tether assembly according to claim 12 or 13, wherein the resiliently compressible member comprises a polymer material.

17. The tether assembly of claim 16, wherein the tether handle assembly is attached to the proximal end of the pull line at the proximal end of the elongated body, and wherein the tether handle assembly is configured to cause the proximal movement of the pull line by converting a force applied by a user toward the actuator toward the distal side into the proximal movement of the pull line.

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