Mechanism for axially and rotationally coupling dilators and sheaths

Abstract

A system (200) for facilitating access to a heart of a patient includes a sheath (202) having a sheath body defining a lumen adapted to receive a dilator (205). A sheath hub (206) is coupled to a proximal portion of the sheath. The sheath hub includes a passage for receiving a portion of a dilator hub and a protrusion adjacent the passage. The dilator has a dilator shaft defining a lumen that receives and supports a puncture device. The dilator shaft includes a proximal portion for manipulation by a user and a tapered distal portion for placement in or near the heart. A dilator hub (212) is coupled to the proximal portion of the dilator shaft. The dilator hub includes a flange (214) having an opening (216) configured to receive a portion of the sheath hub to inhibit relative rotation between the dilator and the sheath.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 566,461, filed March 18, 2024, entitled “MECHANISM AXIALLY ANDROTATIONALLY COUPLING A DILATOR AND SHEATH,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention generally relates to methods and apparatus for delivering treatment to patients. More specifically, this invention relates to a system and method for delivering a therapeutic device to the heart. Background Technology

[0004] Devices exist for creating punctures, channels, or perforations within tissues located in a patient's body. One such device is the Brockenbrough™ needle, commonly used for puncturing the atrial septum of the heart. This device is a rigid, elongated needle configured to be inserted into the patient's body via the femoral vein and guided toward the heart. This device relies on the use of mechanical force to drive the pointed tip through the septum. Alternatively, radiofrequency perforation devices have been developed, whereby septal perforation is achieved by applying focused radiofrequency energy to the septal tissue via electrodes located at the distal end of a relatively thin conductive probe.

[0005] These types of perforation devices are typically used in conjunction with dilators to help support and guide the perforation device. These dilators are often used in conjunction with treatment sheaths suitable for delivering treatment to the patient. Summary of the Invention

[0006] Example 1 is an dilator for facilitating access to a patient's heart and for engagement with a sheath including a sheath hub. The dilator includes a dilator shaft defining a lumen adapted to receive and support a puncture device. The dilator shaft includes a proximal portion for user manipulation and a distal portion for placement within or near the heart. The dilator hub is engaged with the proximal portion of the dilator shaft. The dilator hub includes a flange with an opening. This opening is configured to receive a portion of the sheath hub to inhibit relative rotation between the dilator and the sheath.

[0007] Example 2 is the expander described in Example 1, wherein the expander hub is directly connected to the expander shaft.

[0008] Example 3 is the dilator described in Example 1 or 2, wherein the sheath is a treatment sheath and the puncture device is an RF puncture device.

[0009] Example 4 is an expander as described in any one of Examples 1-3, further comprising an axial locking feature configured to resist axial disengagement forces, such that the expander hub is axially fixed within the sheath hub.

[0010] Example 5 is an expander as described in any one of Examples 1-4, wherein the axial locking feature includes a protrusion adapted to engage with a shoulder.

[0011] Example 6 is the expander described in Example 5, wherein the protrusion is annular.

[0012] Example 7 is an expander as described in any one of Examples 1-6, wherein the flange comprises an asymmetrical shape along a vertical axis and a symmetrical shape along a horizontal axis.

[0013] Example 8 is an expander as described in any one of Examples 1-7, wherein the opening is aligned with the vertical axis or the horizontal axis.

[0014] Example 9 is an expander as described in any one of Examples 1-8, wherein the opening has an arc length in the range of 1 mm to 15 mm.

[0015] Example 10 is an expander as described in any one of Examples 1-9, wherein the opening has an arc angle measurement in the range of 20 degrees to 45 degrees.

[0016] Example 11 is an expander as described in any one of Examples 1-10, wherein the first half of the flange is generally semi-circular.

[0017] Example 12 is an expander as described in any one of Examples 1-11, wherein the second half of the flange is generally elliptical.

[0018] Example 13 is an expander as described in any one of Examples 11 or 12, wherein a first half of the flange has a first radius, and a second half of the flange has a second radius greater than the first radius, or the second radius is the same as the first radius but eccentric.

[0019] Example 14 is the expander described in Example 13, wherein the opening is located in the second half of the flange.

[0020] Example 15 is the expander described in Example 14, wherein the opening has an arc length in the range of 1 mm to 15 mm and an arc angle measurement in the range of 20 degrees to 45 degrees.

[0021] Example 16 is an dilator for facilitating access to a patient's heart and for engagement with a sheath including a sheath hub. The dilator includes a dilator shaft defining a lumen adapted to receive and support a puncture device. The dilator shaft includes a proximal portion for user manipulation and a tapered distal portion for placement in or near the heart. The dilator hub is engaged with the proximal portion of the dilator shaft. The dilator hub includes a flange with an opening. This opening is configured to receive a portion of the sheath hub to inhibit relative rotation between the dilator and the sheath.

[0022] Example 17 is the expander described in Example 16, further including an axial locking feature configured to resist axial disengagement forces, such that the expander hub is axially fixed within the sheath hub.

[0023] Example 18 is the expander described in Example 17, wherein the axial locking feature includes annular protrusions adapted to engage with a shoulder.

[0024] Example 19 is the expander described in Example 16, wherein the flange includes an asymmetrical shape along the vertical axis and a symmetrical shape along the horizontal axis.

[0025] Example 20 is the expander described in Example 16, wherein the opening is aligned with the vertical axis or the horizontal axis.

[0026] Example 21 is the expander described in Example 16, wherein the opening has an arc length in the range of 1 mm to 15 mm.

[0027] Example 22 is the expander described in Example 16, wherein the opening has an arc angle measurement in the range of 20 degrees to 45 degrees.

[0028] Example 23 is the expander described in Example 16, wherein the first half of the flange is generally semi-circular.

[0029] Example 24 is the expander described in Example 23, wherein the second half of the flange is generally elliptical.

[0030] Example 25 is the expander described in Example 16, wherein a first half of the flange has a first radius, and a second half of the flange has a second radius greater than the first radius, or the second radius is the same as the first radius but eccentric.

[0031] Example 26 is the expander described in Example 25, wherein the opening is located in the second half of the flange.

[0032] Example 27 is a sheath for facilitating access to a patient's heart and for coupling with an dilator including a dilator hub. The sheath includes a sheath shaft defining a lumen adapted to receive and support the dilator. The sheath shaft includes a proximal portion for user manipulation and a distal opening through which the dilator can extend. The sheath hub is coupled to the proximal portion of the sheath shaft. The sheath hub includes a passage for receiving a portion of the dilator hub and a protrusion adjacent to the passage. The protrusion is configured to contact a flange of the dilator hub to inhibit relative rotation between the sheath and the dilator.

[0033] Example 28 is the sheath described in Example 27, wherein the protrusion has an arc length in the range of 1 mm to 15 mm.

[0034] Example 29 is the sheath described in Example 27, wherein the protrusion has an arc angle measurement in the range of 20 degrees to 45 degrees.

[0035] Example 30 is the sheath described in Example 27, wherein the protrusion prevents the expander from being improperly inserted into the sheath.

[0036] Example 31 is the sheath described in Example 27, wherein the protrusion includes at least one angled surface.

[0037] Example 32 is a system for facilitating access to a patient's heart. The system includes a sheath having a sheath body defining a lumen adapted to receive a dilator. The sheath body includes a proximal portion and a distal portion. A sheath hub is coupled to the proximal portion of the sheath. The sheath hub includes a passage for receiving a portion of the dilator hub and a protrusion adjacent to the passage. The system includes a dilator having a dilator shaft defining a lumen adapted to receive and support a puncture device. The dilator shaft includes a proximal portion for user manipulation and a tapered distal portion for placement in or near the heart. The dilator hub is coupled to the proximal portion of the dilator shaft. The dilator hub includes a flange having an asymmetrical shape along a vertical axis and a symmetrical shape along a horizontal axis.

[0038] Example 33 is the system described in Example 32, wherein the flange includes an opening aligned with the horizontal axis.

[0039] Example 34 is the system described in Example 33, wherein the protrusion is configured to fit within the opening to suppress relative rotation between the sheath and the expander.

[0040] Example 35 is the system described in Example 33, wherein the opening has an arc length in the range of 1 mm to 15 mm and an arc angle measurement in the range of 20 degrees to 45 degrees.

[0041] While several embodiments have been disclosed, other embodiments of the invention will become apparent to those skilled in the art from the following detailed description, which illustrates and describes illustrative embodiments of the invention. Therefore, the drawings and detailed description should be considered illustrative in nature, not restrictive. Attached Figure Description

[0042] Figures 1A-1C This is a schematic diagram of a medical procedure performed in a patient's heart using a transatrial septal approach system according to an embodiment of the present invention.

[0043] Figure 2 This is a perspective view of an expander according to an embodiment of the present invention, wherein the expander hub is inserted into the sheath hub.

[0044] Figure 3 This is an embodiment of the present invention. Figure 2 expander hub and Figure 2 A perspective view of the sheath and hub assembly.

[0045] Figure 4A and Figure 4B This is an embodiment of the present invention. Figure 2 The expander and sheath hub are in an incorrectly oriented perspective view.

[0046] Figure 5 This is an embodiment of the present invention. Figure 2 End view of the sheath hub.

[0047] Figure 6 This is an embodiment of the present invention. Figure 2 End view of the expander hub.

[0048] Figure 7A This is an embodiment of the present invention. Figure 2 expander hub and Figure 2 A cross-sectional view of the mating sheath and hub portion.

[0049] Figure 7B This is an embodiment of the present invention. Figure 2 expander hub and Figure 2 A cross-sectional view showing the complete fit between the sheath and the hub.

[0050] While the invention can be modified and alternatively implemented in various ways, specific embodiments have been shown by way of example in the accompanying drawings and are described in detail below. However, it is not intended to limit the invention to the described embodiments. Rather, the invention is intended to cover all modifications, equivalents, and alternatives that fall within the scope of the invention as defined in the appended claims. Detailed Implementation

[0051] Figures 1A-1C This is a schematic diagram of a medical procedure 10 performed within a patient's heart 20 using an atrial septum approach system 50 according to an embodiment of the present disclosure. As is known, the human heart 20 has four chambers: a right atrium 55, a left atrium 60, a right ventricle 65, and a left ventricle 70. The atrial septum 75 separates the right atrium 55 and the left atrium 60, while the interventricular septum 80 separates the right ventricle 65 and the left ventricle 70. As is further known, deoxygenated blood from the patient's body returns to the right atrium 55 via the inferior vena cava (IVC) 85 or the superior vena cava (SVC) 90.

[0052] Various medical procedures have been developed for the diagnosis or treatment of physiological disorders originating in the left atrium 60 and associated structures. Exemplary such procedures include, but are not limited to, the deployment of a diagnostic or mapping catheter within the left atrium 60 to generate an electroanatomical mapping or diagnostic image thereof. Other exemplary procedures include catheter-based endocardial ablation (e.g., radiofrequency ablation, pulsed field ablation, cryoablation, laser ablation, high-frequency ultrasound ablation, etc.) of a target site within a chamber or adjacent vessel (e.g., pulmonary veins and pulmonary vein orifices) to terminate arrhythmias such as atrial fibrillation and atrial flutter. Other exemplary procedures may include the deployment of a left atrial appendage (LAA) occlusion device. Of course, the foregoing examples of procedures performed within the left atrium 60 are merely illustrative and are by no means limiting of this disclosure.

[0053] Figures 1A-1C The medical procedure 10 shown is an exemplary embodiment that uses a transatrial septal access system 50 to provide access to the left atrium 60 for subsequent deployment of the aforementioned diagnostic and / or therapeutic devices within the left atrium 60. Figures 1A-1C As shown, the target tissue site can be defined by tissue on the interatrial septum 75. In the illustrated embodiment, the target site is approached via IVC 85 (e.g., through the femoral vein) according to conventional catheter insertion techniques. In other embodiments, access to the target site on the interatrial septum 75 can be achieved using a superior approach, wherein the ventricle is advanced into the right atrium 55 via SVC 90 through the interatrial septum access system 50.

[0054] In the illustrated embodiment, the transatrial septal approach system 50 includes a guide sheath 100, a dilator 105 having a dilator body 107 and a tapered distal end portion 108, and a perforation device (e.g., a radio frequency (RF) perforation device) 110 having a distal end portion 112 terminating at a distal electrode 115. As shown, in Figures 1A-1CIn the assembled and used configuration shown, the RF puncture device 110 can be housed within the dilator 105, which itself can be housed within the sheath 100. In one embodiment, deployed to the right atrium 55 via the interventricular septal approach system 50 through the IVC 105, the user introduces a guidewire (not shown) into the femoral vein (typically the right femoral vein) and advances it toward the heart 20. The sheath 100 can then be introduced over the guidewire into the femoral vein and advanced toward the heart 20. In one embodiment, the distal ends of the sheath 100 and the guidewire are then positioned in the SVC 90. These steps can be performed using an imaging system (e.g., fluoroscopy or ultrasound imaging). The dilator 105 can then be introduced into the sheath 100 and over the guidewire, and advanced through the sheath 100 and into the SVC 90. Alternatively, the dilator 105 can be fully inserted into the sheath 100 before entering the body, and the dilator and the sheath can be advanced toward the heart 20 simultaneously. Once the guidewire, sheath 100, and dilator 105 are positioned in the SVC 90, the guidewire is removed from the body, and the sheath 100 and dilator 105 retract, positioning their distal ends in the right atrium 55. The described RF puncture device 110 can then be introduced into the dilator 105 and advanced toward the heart 20. In various embodiments, the guidewire and RF puncture device are the same component and therefore do not need to be interchanged.

[0055] Subsequently, the user can position the distal end of the dilator 105 against the interatrial septum 75, which can be done under imaging guidance. The RF puncture device 110 is then positioned such that the electrode 115 is aligned with or slightly protrudes from the distal end of the dilator 105. The dilator 105 and the RF puncture device 110 can be dragged along the interatrial septum 75 under imaging guidance and positioned, for example, against the foramen ovale of the interatrial septum 75. Various additional steps can be performed, such as measuring one or more characteristics of the target site, such as electrophoresis or ECG (electrocardiogram) tracking and / or pressure measurement, or delivering materials to the target site, such as delivering contrast agents. Such steps can facilitate the positioning of the distal electrode 115 at the desired target site. Additionally, tactile feedback provided by the medical RF puncture device 110 can be used to facilitate the positioning of the distal electrode 115 at the desired target site.

[0056] With the distal electrode 115 and dilator 105 positioned at the target site, energy is delivered from an energy source (e.g., an RF generator) via the RF puncture device 110 to the distal electrode 115 and the target site. In some embodiments, the energy is delivered at a voltage of at least about 75V (peak-to-peak) and a power of at least about 5W, and is used to vaporize cells near the distal electrode 115, thereby creating a gap or perforation through the tissue at the target site. The user then applies force to the RF puncture device 110 to at least partially advance the distal electrode 115 through the perforation. In these embodiments, energy delivery stops when the distal electrode 115 has penetrated the target tissue, that is, when the distal electrode has reached the left atrium 60. In some embodiments, the energy delivery step occurs over a time period between about 1 second and about 5 seconds.

[0057] With the distal electrode 115 of the RF puncture device 110 having passed through the interatrial septum 75, the dilator 105 can be advanced forward, and the distal conical end portion 108 operates to gradually enlarge the perforation to allow the distal end of the sheath 100 to be advanced into the left atrium 60.

[0058] In some embodiments, the distal end portion 112 of the RF puncture device 110 may be pre-formed to present a non-invasive shape, such as a J-shape (e.g., Figures 1B-1C (as shown), a tail-like shape, or other shapes selected to guide the distal electrode 115 away from the endocardial surface of the left atrium 60. Examples of such RE puncture devices can be found, for example, in U.S. Patent Applications Nos. 16 / 445,790 and 16 / 346,404 assigned to Baylis Medical Company, Inc. The aforementioned pre-formed shapes can advantageously minimize the risk of accidental contact between the distal electrode 115 and tissue within the left atrium 60, and can also be operated to anchor the distal end portion 112 within the left atrium 60 during subsequent procedural steps. For example, in an embodiment, the RF puncture device 110 can be structurally configured as a delivery track for deploying a relatively large-aperture therapeutic delivery sheath and associated dilator. In such embodiments, after the distal end portion 112 of the RF puncture device 110 has been deployed into the left atrium 60, the dilator 105 and sheath 100 are withdrawn. During such retraction, the anchoring function of the pre-formed distal end portion 112 prevents accidental retraction of the distal end portion 112 and, correspondingly, prevents the loss of access to the perforation site on the interatrial septum 75.

[0059] Various medical procedures have been developed for the diagnosis or treatment of physiological disorders originating in the left atrium 60 and associated structures. Exemplary such procedures include, but are not limited to, the deployment of a diagnostic or mapping catheter within the left atrium 60 to generate an electroanatomical mapping or diagnostic image thereof. Other exemplary procedures include catheter-based endocardial ablation (e.g., radiofrequency ablation, pulsed field ablation, cryoablation, laser ablation, high-frequency ultrasound ablation, etc.) of a target site within a chamber or adjacent vessel (e.g., pulmonary veins and pulmonary vein orifices) to terminate arrhythmias such as atrial fibrillation and atrial flutter. Other exemplary procedures may include the deployment of a left atrial appendage (LAA) occlusion device. Of course, the foregoing examples of procedures performed within the left atrium 60 are merely illustrative and are by no means limiting of this disclosure.

[0060] In some embodiments, the catheter, treatment device, and sheath can be deployed through the sheath 100 after it has been successfully deployed into the desired cardiac chamber (e.g., the left atrium). In other embodiments, the treatment device (e.g., mapping catheter, treatment sheath, medical device, etc.) is part of the sheath 100, thereby forming a treatment sheath.

[0061] Figure 2 This is a perspective view of a system 200 for facilitating access to a patient's heart. According to an embodiment of the invention, the system includes an expander 204 having an expander hub 212 configured for insertion into a sheath 202 having a sheath hub 206. As shown, the expander 204 is partially inserted into the lumen of the sheath 202. The expander 205 includes a handle 208, an expander hub 212, a proximal connector 210, and an expander shaft 205. The sheath 202 includes a sheath hub 206 and a sheath shaft (not shown) defining a lumen adapted to receive and support the expander shaft 205. The sheath shaft includes a proximal portion for user manipulation and a distal opening through which the expander can extend, as described above. Figures 1A-1C The sheath hub 206 is connected to the proximal portion of the sheath shaft. The sheath hub 206 can be directly or indirectly connected to the sheath shaft. The sheath hub 206 includes a passage 220 for receiving a portion of the expander hub and a protrusion 222 adjacent to the passage 220. The protrusion 222 is configured to contact the flange 214 of the expander hub 212 to inhibit relative rotation between the sheath 202 and the expander 204, such that when the user rotates the sheath 202 or the expander 204, they rotate together as a single unit.

[0062] The dilator 204 includes a dilator shaft 205 that defines a lumen adapted to receive and support a puncture device. The puncture device can be inserted into the dilator 204 using a proximal connector 210. The proximal connector 210 is also configured to connect to a fluid delivery device, such as a syringe or other container, for delivering fluid (e.g., a contrast agent) through the dilator shaft 205. The puncture device may include a mechanical puncture device, such as a guidewire with a needle tip, or an RF puncture device. The dilator shaft 205 includes a proximal portion for user manipulation and a distal portion for placement in or near the heart. A dilator hub 212 is coupled to the proximal portion of the dilator shaft 205. The dilator hub 212 may be directly or indirectly coupled to the dilator shaft 205. The dilator hub 212 includes a flange 214 having an asymmetrical shape along a vertical axis and a symmetrical shape along a horizontal axis. The flange 214 includes an opening 216 configured to receive a protrusion 222. When the protrusion 222 is received in the opening 216, relative rotation between the expander 204 and the sheath 202 is suppressed or prevented. This creates a rotational lock between the two components. This allows the user to rotate the expander 204 and the sheath 202 together simultaneously.

[0063] Figure 3 This is an embodiment of the present invention. Figure 2 A perspective view of the expander hub 212, which is related to... Figure 2 The sheath hub 206 is properly positioned and fully inserted therein. For example... Figure 3 As shown, the expander hub 212 is inserted into the passage 220 until the flange 214 contacts the surface of the sheath hub 206. This orientation prevents relative rotation of the expander 204 relative to the sheath 202. The protrusion 222 must be aligned with the opening 216 so that the flange 214 fully abuts the sheath hub 206 and the protrusion 222 is received within the opening 216.

[0064] Figure 4A and Figure 4B yes Figure 2 The expander 204 and sheath hub 206 are in an incorrectly oriented perspective view. Figure 4A In this configuration, the expander 204 has rotated approximately 180 degrees from being correctly inserted into the sheath 202. As shown, the flange 214 abuts the protrusion 222. This prevents the expander hub 212 from being fully inserted into the sheath hub 206 and provides the user with tactile feedback indicating that the expander 204 and sheath 202 are not properly aligned. Similarly, in Figure 4B In this configuration, the expander 204 is not properly aligned with the sheath 202. Therefore, the expander hub 212 is prevented from being properly received in the sheath hub 206 by the interaction of the flange 214 and the protrusion 222.

[0065] Figure 5 This is an embodiment of the present invention. Figure 2 An end view of the sheath hub 206. The sheath hub 206 includes a passage 220 for receiving a portion of the expander hub 212. A protrusion 222 is adjacent to the passage 220. The protrusion 222 is aligned with a horizontal axis passing through the center of the sheath hub 206. The protrusion 220 is configured to contact the flange 214 of the expander hub via an opening 216 to inhibit relative rotation between the sheath and the expander. The protrusion 222 has an arc length Lp in the range of 1 mm to 15 mm. The protrusion 222 has an arc angle measurement β in the range of 20 degrees to 45 degrees. The arc length Lp of the protrusion 222 is minimized so that the protrusion 222 does not interfere with the user's grip on the expander 204, and also provides sufficient strength to prevent the protrusion 222 from breaking.

[0066] The protrusion 222 includes an inner surface 224 closest to the opening 216 and an outer surface 226 opposite to the inner surface 226. An edge 228 extends between the inner surface 224 and the outer surface 226. The heights of the inner surface 224 and the outer surface 226 may be different, such that the edge 228 is angled relative to the longitudinal axis of the sheath hub 206 passing through the opening 216.

[0067] Figure 6 This is an embodiment of the present invention. Figure 2 End view of the expander hub 212. (See image) Figure 6 As shown, the flange 214 of the expander hub 212 has an asymmetrical shape along the vertical axis 252 and a symmetrical shape along the horizontal axis 254. The vertical axis 252 and the horizontal axis 254 pass through the longitudinal axis of the expander 204. The first half 214a of the flange 214 is generally semi-circular. The first half 214a of the flange 214 includes a radius R1. The second half 214b of the flange 214 is generally elliptical. In some embodiments, the first half 214a of the flange 214 has a first radius R1, while the second half 214b of the flange 214 has a second radius R2 greater than the first radius R1. In some embodiments, the second half 214b of the flange 214 has the same radius R1 as the first half 214a, but is eccentric. In some embodiments, the flange 214 does not have an asymmetrical shape along the vertical axis 252, but has a uniform radius.

[0068] like Figure 6As shown, opening 216 is located in the second half 214b of flange 214. Opening 216 is aligned with an axis orthogonal to the longitudinal axis of the expander. In one embodiment, opening 216 is aligned with horizontal axis 254. The opening has an arc length Lf in the range of 1 mm to 15 mm. Opening 216 has an arc angle measurement α in the range of 20 degrees to 45 degrees. When engaged with protrusion 222, opening 216 partially surrounds protrusion 222. The outer surface 226 of protrusion 222 is not surrounded by opening 216. Opening 216 includes a surface that interacts with the edge 228 of protrusion.

[0069] Figure 7A This is an embodiment of the present invention. Figure 2 The expander hub 212 and Figure 2 A cross-sectional view of the mating portion of the sheath hub 206, and Figure 7B This is a cross-sectional view of the expander hub 212 and sheath hub 206 fully engaged according to an embodiment of the present invention. The distal end of the expander hub 212 includes an axial locking feature comprising a protrusion 218. In some embodiments, the protrusion 218 is an annular protrusion located on the outer circumference of the expander hub 212. The annular protrusion 218 is adapted to engage with a corresponding shoulder 219 within the sheath hub 206. The interaction between the protrusion 218 and the shoulder 219 resists axial disengagement forces, thereby axially securing the expander hub 212 within the sheath hub 206. In one aspect, the shoulder 219 takes the form of an elastic and deformable O-ring. When the expander hub 212 is inserted into the sheath hub 206, the annular protrusion 218 deforms the O-ring and allows it to enter the locking chamber 237, as... Figure 7B As shown in the diagram, the annular protrusion 218 is held within the locking chamber 237 and cannot move proximally past the shoulder 219 to axially lock the expander hub 212 to the sheath hub 206. In one aspect, the locking chamber 237 is configured to allow slight axial movement of the annular protrusion 218 by providing a gap between the shoulder 219 and the annular protrusion 218. In another aspect, the locking chamber 237 is configured to firmly hold the annular protrusion 218, wherein the annular protrusion 218 contacts the shoulder 219. The expander hub 212 and the sheath hub 206 are configured such that when the annular protrusion 218 is positioned within the locking chamber 237, the flange 214 abuts the sheath hub 206, and the protrusion 222 is located within the opening 216 of the flange 214 to resist or prevent relative rotation as discussed above.

[0070] To remove the expander hub 212 from the sheath hub 206, a disengagement force can be generated through the interaction of the angled surfaces of edge 228 with surfaces 217a, 217b, and 217c. The angled surfaces of edge 228 and surfaces 217a, 217b, and 217c can have slightly different angles or the same angle (but are not horizontally oriented), such that an axial disengagement force is generated when torque is applied to the expander hub 212. This disengagement force (with an axial force component) causes axial movement of the expander hub 212, disengaging it from the sheath hub 206. When the disengagement force becomes sufficient to overcome the axial locking force formed by the interaction of the annular protrusion 218 and the shoulder 219, relative movement occurs in both the axial and rotational directions, allowing the expander hub 212 to be removed from the sheath hub 206. The amount of torque and the degree of rotation required for disengagement can be adjusted by changing the angles of these surfaces.

[0071] Various modifications and additions may be made to the exemplary embodiments discussed without departing from the scope of the invention. For example, while the above embodiments relate to specific features, the scope of the invention also includes embodiments having different combinations of features and embodiments that do not include all of the stated features. Therefore, the scope of the invention is intended to cover all such alternatives, modifications, and variations, and all equivalents thereof, falling within the scope of the claims.

Claims

1. An expander for easy access to a patient's heart and for engagement with a sheath including a sheath hub, the expander comprising: An expander shaft defining a lumen adapted to receive and support a puncture device, the expander shaft including a proximal portion for manipulation by a user and a distal portion for placement in or near the heart; and An expander hub, which is coupled to a proximal portion of the expander shaft, includes a flange having an opening configured to receive a portion of the sheath hub to suppress relative rotation between the expander and the sheath.

2. The expander according to claim 1, wherein, The expander hub is directly connected to the expander shaft.

3. The expander according to claim 1 or 2, wherein, The sheath is a treatment sheath, and the puncture device is an RF puncture device.

4. The expander according to any one of claims 1-3, further comprising an axial locking feature configured to resist axial disengagement forces, such that the expander hub is axially fixed within the sheath hub.

5. The expander according to any one of claims 1-4, wherein, The axial locking feature includes a protrusion adapted to engage with the shoulder.

6. The expander according to claim 5, wherein, The protrusion is ring-shaped.

7. The expander according to any one of claims 1-6, wherein, The flange includes an asymmetrical shape along the vertical axis and a symmetrical shape along the horizontal axis.

8. The expander according to any one of claims 1-7, wherein, The opening is aligned with the vertical axis or the horizontal axis.

9. The expander according to any one of claims 1-8, wherein, The opening has an arc length in the range of 1 mm to 15 mm.

10. The expander according to any one of claims 1-9, wherein, The opening has an arc angle measurement value in the range of 20 degrees to 45 degrees.

11. The expander according to any one of claims 1-10, wherein, The first half of the flange is approximately semi-circular.

12. The expander according to any one of claims 1-11, wherein, The second half of the flange is approximately elliptical.

13. The expander according to any one of claim 11 or 12, wherein, The first half of the flange has a first radius, and the second half of the flange has a second radius that is greater than the first radius, or the second radius is the same as the first radius but eccentric.

14. The expander according to claim 13, wherein, The opening is located in the second half of the flange.

15. The expander according to claim 14, wherein, The opening has an arc length in the range of 1 mm to 15 mm and an arc angle measurement in the range of 20 degrees to 45 degrees.

16. An expander for facilitating access to a patient's heart and for engagement with a sheath including a sheath hub, the expander comprising: An expander shaft defining a lumen adapted to receive and support a puncture device, the expander shaft including a proximal portion for manipulation by a user and a tapered distal portion for placement in or near the heart; and An expander hub, which is coupled to a proximal portion of the expander shaft, includes a flange having an opening configured to receive a portion of the sheath hub to suppress relative rotation between the expander and the sheath.

17. The expander of claim 16, further comprising an axial locking feature configured to resist axial disengagement forces, such that the expander hub is axially fixed within the sheath hub.

18. The expander according to claim 17, wherein, The axial locking feature includes annular protrusions adapted to engage with the shoulder.

19. The expander according to claim 16, wherein, The flange includes an asymmetrical shape along the vertical axis and a symmetrical shape along the horizontal axis.

20. The expander according to claim 16, wherein, The opening is aligned with the vertical axis or the horizontal axis.

21. The expander according to claim 16, wherein, The opening has an arc length in the range of 1 mm to 15 mm.

22. The expander according to claim 16, wherein, The opening has an arc angle measurement value in the range of 20 degrees to 45 degrees.

23. The expander according to claim 16, wherein, The first half of the flange is approximately semi-circular.

24. The expander according to claim 23, wherein, The second half of the flange is approximately elliptical.

25. The expander according to claim 16, wherein, The first half of the flange has a first radius, and the second half of the flange has a second radius that is greater than the first radius, or the second radius is the same as the first radius but eccentric.

26. The expander according to claim 25, wherein, The opening is located in the second half of the flange.

27. A sheath for facilitating access to a patient's heart and for coupling with an expander including an expander hub, the sheath comprising: A sheath shaft defining a lumen adapted to receive and support a dilator, the sheath shaft including a proximal portion for user manipulation and a distal opening through which the dilator can extend; and A sheath hub, which is coupled to the proximal portion of the sheath shaft, the sheath hub includes a passage for receiving a portion of the expander hub and a protrusion adjacent to the passage, the protrusion being configured to contact the flange of the expander hub to inhibit relative rotation between the sheath and the expander.

28. The sheath according to claim 27, wherein, The protrusion has an arc length in the range of 1 mm to 15 mm.

29. The sheath according to claim 27, wherein, The protrusion has an arc angle measurement value in the range of 20 degrees to 45 degrees.

30. The sheath according to claim 27, wherein, The protrusion prevents the expander from being improperly inserted into the sheath.

31. The sheath according to claim 27, wherein, The protrusion includes at least one angled surface.

32. A system for facilitating access to a patient's heart, the system comprising: A sheath having a sheath body defining a lumen suitable for receiving a dilator, the sheath body including a proximal portion and a distal portion; A sheath hub, which is connected to a proximal portion of the sheath, the sheath hub including a passage for receiving a portion of the expander hub and a protrusion adjacent to the passage; An expander having an expander shaft defining a lumen adapted to receive and support a puncture device, the expander shaft including a proximal portion for manipulation by a user and a conical distal portion for placement in or near the heart; as well as An expander hub, which is connected to the proximal portion of the expander shaft, the expander hub including a flange having an asymmetrical shape along a vertical axis and a symmetrical shape along a horizontal axis.

33. The system according to claim 32, wherein, The flange includes an opening aligned with the horizontal axis.

34. The system according to claim 33, wherein, The protrusion is configured to fit within the opening to inhibit relative rotation between the sheath and the expander.

35. The system according to claim 33, wherein, The opening has an arc length in the range of 1 mm to 15 mm and an arc angle measurement in the range of 20 degrees to 45 degrees.

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