Patent Application
20250127564
The present invention relates generally to systems and methods for deflectable medical catheters. More specifically, the present invention is concerned with a steerable sheath having a deflectable distal tip curve position indicator which provides a visual cue of the steerable sheath deflectable distal tip curve direction.
Existing steerable sheaths, like the SureFlex steerable sheath, do not indicate on the handle, or anywhere else on the device, the amount and/or the direction of deflection of the distal portion of the sheath. Generally, for steerable sheaths, deflection is possible based on rotation of a knob on the sheath. If more than one rotation of the knob is required to fully deflect the sheath, it is difficult to correlate the amount of knob rotation with the amount of distal portion sheath deflection. Additionally, when the sheath is inserted in the body of a patient, the user must rely on fluoroscopy to indicate the distal tip position of the sheath. This process increases radiation exposure to both the user and the patient. Moreover, if multiple steerable sheaths are used simultaneously, the sheaths cannot be distinguished based on their curve positions. This may especially create an array of issues during procedures which require fine adjustment of the position of the distal tip, like in transseptal crossing procedures and ablating tissue within the heart of a patient.
Against this background, there exists a continuing need in the industry to provide improved steerable sheaths having a sheath curve position indicator. Specifically, for use in transseptal procedures. An object of the present invention is therefore to provide such a steerable sheath.
In Example 1, a steerable sheath includes an elongate member defining a lumen, the elongate member having a proximal portion and a distal portion terminating in a deflectable distal tip. The steerable sheath further includes a handle defining a handle lumen having a handle proximal portion and a handle distal portion that is connected to the proximal portion of the elongate member, the handle comprising: a rotatable knob; a slider running through a portion of the handle having a raised thread and an inverted thread, a first direction of the raised thread being inverse to a second direction of the inverted thread; and a position ring located proximate a position indicator, the position ring and the position indicator each having one or more bevel gears connecting the position ring to the position indicator, the position indicator located proximate the knob, wherein rotation of the knob acts upon the raised thread to cause a linear movement of the slider which acts upon the inverted thread to cause a rotational movement of the position ring.
Example 2 is the steerable sheath of Example 1 wherein the one or more bevel gears of the position ring rotate the one or more bevel gears of the position indicator.
Example 3 is the steerable sheath of any of Examples 1-2 wherein the rotational movement of the position ring translates to rotation of the position indicator.
Example 4 is the steerable sheath of Example 1 wherein the direction of the position indicator coincides with the curved direction of the deflectable distal tip.
Example 5 is the steerable sheath of Example 1 wherein the handle further includes two or more pull wires connected to the slider.
Example 6 is the steerable sheath of Example 5 wherein the pull wires control the curve direction of the deflectable distal tip.
Example 7 is the steerable sheath of Example 1 wherein the position ring is connected to the inverted thread by a connector tab.
Example 8 is the steerable sheath of Example 1 wherein the knob is rotated by a user depending on the desired direction of curvature of the deflectable distal tip.
Example 9 is the steerable sheath of any of Examples 1-8 wherein the position indicator provides a visual cue to the user indicating the curve direction of the deflectable distal tip of the steerable sheath.
Example 10 is the steerable sheath of Example 1 wherein the pitch of the raised thread is higher than the pitch of the inverted thread.
Example 11 is the steerable sheath of Example 1 wherein the pitch of the raised thread is between 10 mm to 15 mm.
Example 12 is the steerable sheath of Example 1 wherein the pitch of the inverted thread is between 45 mm to 55 mm.
Example 13 is the steerable sheath of Example 1 wherein the system further includes a puncture device configured to advance through the steerable sheath.
Example 14 is the steerable sheath of Example 1 wherein the system further includes a medical therapy device configured to advance through the steerable sheath.
Example 15 is the steerable sheath of Example 14 wherein the medical therapy device is an ablation catheter.
In Example 16, a steerable sheath includes an elongate member defining a lumen, the elongate member having a proximal portion and a distal portion terminating in a deflectable distal tip. The steerable sheath further includes a handle defining a handle lumen having a handle proximal portion and a handle distal portion that is connected to the proximal portion of the elongate member, the handle comprising: a rotatable knob; a slider running through a portion of the handle having a raised thread and an inverted thread, a first direction of the raised thread being inverse to a second direction of the inverted thread; and a position ring located proximate a position indicator, the position ring and the position indicator each having one or more bevel gears connecting the position ring to the position indicator, the position indicator located proximate the knob, wherein rotation of the knob acts upon the raised thread to cause a linear movement of the slider which acts upon the inverted thread to cause a rotational movement of the position ring.
Example 17 is the steerable sheath of Example 16 wherein the one or more bevel gears of the position ring rotate the one or more bevel gears of the position indicator, and wherein the rotational movement of the position ring translates to rotation of the position indicator.
Example 18 is the steerable sheath of Example 16 wherein the direction of the position indicator coincides with the curved direction of the deflectable distal tip.
Example 19 is the steerable sheath of Example 16 wherein the handle further includes two pull wires connected to the slider, and wherein the pull wires control the curve direction of the deflectable distal tip.
Example 20 is the steerable sheath of Example 16 wherein the position ring is connected to the inverted thread by a connector tab.
Example 21 is the steerable sheath of Example 16 wherein the knob is rotated by a user depending on the desired direction of curvature of the deflectable distal tip, and wherein the position indicator provides a visual cue to the user indicating the curve direction of the deflectable distal tip of the steerable sheath.
Example 22 is the steerable sheath of Example 16 wherein the pitch of the raised thread is higher than the pitch of the inverted thread.
Example 23 is the steerable sheath of Example 16 wherein the pitch ratio of the raised thread to the inverted thread is 4:1.
Example 24 is the steerable sheath of Example 16 wherein the pitch of the raised thread is between 10 mm to 15 mm.
Example 25 is the steerable sheath of Example 16 wherein the pitch of the inverted thread is between 45 mm to 55 mm.
Example 26 is the steerable sheath of Example 16 wherein the system further includes a puncture device and an ablation device configured to advance through the steerable sheath.
In Example 27, a steerable sheath for transseptal crossing and subsequent therapy includes an elongate member defining a lumen, the elongate member having a proximal portion and a distal portion terminating in a deflectable distal tip. The steerable sheath further includes a handle defining a handle lumen having a handle proximal portion and a handle distal portion that is connected to the proximal portion of the elongate member. The handle further comprises a knob positioned at the distal portion of the handle; a slider running through a portion of the handle having a raised thread and an inverted thread, a first direction of the raised thread being inverse to a second direction of the inverted thread; and a position ring located proximate a position indicator, the position ring and the position indicator each having one or more bevel gears connecting the position ring to the position indicator, the position indicator located proximate the knob, wherein rotation of the knob acts upon the raised thread to cause a linear movement of the slider which acts upon the inverted thread to cause a rotational movement of position ring, and wherein the one or more bevel gears of the position ring rotate the one or more bevel gears of the position indicator, and wherein the rotational movement of the position ring translates to rotation of the position indicator.
Example 28 is the steerable sheath of Example 27 wherein the direction of the position indicator coincides with the curved direction of the deflectable distal tip.
Example 29 is the steerable sheath of Example 27 wherein the handle further includes two pull wires connected to the slider, and wherein the pull wires control the curve direction of the deflectable distal tip.
Example 30 is the steerable sheath of Example 27 wherein the position ring is connected to the inverted thread by a connector tab.
Example 31 is the steerable sheath of Example 27 wherein the knob is rotated by a user depending on the desired direction of curvature of the deflectable distal tip, and wherein the position indicator provides a visual cue to the user indicating the curve direction of the deflectable distal tip of the steerable sheath.
Example 32 is the steerable sheath of Example 27 wherein the pitch of the raised thread is higher than the pitch of the inverted thread.
Example 33 is the steerable sheath of Example 27 wherein the system further includes a puncture device and a subsequent medical therapy device configured to advance through the steerable sheath.
Example 34 is the steerable sheath of Example 33 wherein the system further includes a subsequent medical therapy device configured to advance through the steerable sheath.
In Example 35, a method of using a steerable sheath for transseptal crossing and subsequent therapy includes providing an elongate member defining a lumen, the elongate member having a proximal portion and a distal portion terminating in a deflectable distal tip. The method of using a steerable sheath further includes advancing a handle defining a handle lumen having a handle proximal portion and a handle distal portion that is connected to the proximal portion of the elongate member, the handle comprising: a knob positioned at the distal portion of the handle; a slider running through a portion of the handle having a raised thread and an inverted thread, a first direction of the raised thread being inverse to a second direction of the inverted thread; and a position ring located proximate a position indicator, the position ring and the position indicator each having one or more bevel gears connecting the position ring to the position indicator, the position indicator located proximate the knob, wherein rotation of the knob acts upon the raised thread to cause a linear movement of the slider which acts upon the inverted thread to cause a rotation movement position ring.
While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
While the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.
The guidewire 140 is connected to a generator 150 by a connector 152. The steerable sheath 130 includes a steerable sheath handle 132. In some embodiments, the steerable sheath is unidirectional, i.e., it allows deflection in a single direction. In other embodiments, a bi-directional sheath may be used.
As is known, and shown in
Various medical procedures have been developed for diagnosing or treating physiological ailments originating within the left atrium and associated structures. Exemplary such procedures include, without limitation, deployment of diagnostic or mapping catheters within the left atrium for use in generating electroanatomical maps or diagnostic images thereof. Other exemplary procedures include endocardial catheter-based ablation (e.g., radiofrequency ablation, pulsed field ablation, cryoablation, laser ablation, high frequency ultrasound ablation, and the like) of target sites within the chamber or adjacent vessels (e.g., the pulmonary veins and their ostia) to terminate cardiac arrythmias such as atrial fibrillation and atrial flutter. Still other exemplary procedures may include deployment of left atrial appendage (LAA) closure devices. Of course, the foregoing examples of procedures within the left atrium are merely illustrative and in no way limiting with respect to the present disclosure.
The medical procedure of system 110 is an exemplary embodiment for providing access to the left atrium using the transseptal access system with a steerable sheath 130 for subsequent deployment of the aforementioned diagnostic and/or therapeutic devices within the left atrium, as will be discussed in greater detail below. In some embodiments, a target site is accessed via the IVC, for example through the femoral vein, according to conventional catheterization techniques. In other embodiments, access to the target site on the atrial septum may be accomplished using a superior approach wherein the transseptal access system is advanced into the right atrium via the SVC.
In the assembled use state illustrated in
Subsequently, the user may position the distal end of the dilator 120 against the atrial septum, which can be done under imaging guidance. With the aid of the steerable sheath 130, the RF perforation device is then positioned such that the tip electrode is aligned with or protruding slightly from the distal end of the dilator 120. The dilator 120 and the RF perforation device may be dragged along the atrial septum and positioned, for example against the fossa ovalis of the atrial septum under imaging guidance. A variety of additional steps may be performed, such as measuring one or more properties of the target site, for example an electrogram or ECG (electrocardiogram) tracing and/or a pressure measurement, or delivering material to the target site, for example delivering a contrast agent. Such steps may facilitate the localization of the tip electrode at the desired target site. In addition, tactile feedback provided by medical RF perforation device is usable to facilitate positioning of the tip electrode at the desired target site.
With the tip electrode and dilator 120 positioned at the target site, energy is delivered from an energy source, e.g., an RF generator 150, through the RF perforation device to the tip electrode and the target site. In some embodiments, the energy is delivered at a power of at least about 5 W at a voltage of at least about 75 V (peak-to-peak), and functions to vaporize cells in the vicinity of the tip electrode, thereby creating a void or perforation through the tissue at the target site. The user then applies force to the RF perforation device so as to advance the tip electrode at least partially through the perforation. In these embodiments, when the tip electrode has passed through the target tissue, that is, when it has reached the left atrium, energy delivery is stopped. In some embodiments, the step of delivering energy occurs over a period of between about 1 second and about 5 seconds.
With the tip electrode of the RF perforation device having crossed the atrial septum, the dilator 120 can be advanced forward, with the tapered distal tip portion operating to gradually enlarge the perforation to permit advancement of the distal end of the sheath 130 into the left atrium.
In embodiments, the RF perforation device can be structurally configured to function as a delivery rail for deployment of a relatively larger bore therapy delivery sheath and associated dilator(s). In such embodiments, the dilator and the sheath 130 are withdrawn following deployment of the distal end portion of the RF perforation device into the left atrium. The anchoring function of the pre-formed distal end portion inhibits unintended retraction of the distal end portion, and corresponding loss of access to the perforated site on the atrial septum, during such withdrawal.
In the embodiment shown in
The present disclosure describes novel devices and methods for a steerable sheath for transseptal crossing and subsequent advancement of therapy systems. As will be explained in greater detail herein, the embodiments of the present disclosure simplify the means of determining the deflection of the steerable sheath at a distal portion of the sheath, while providing enhanced manipulability to the user.
The handle 336 further includes a slider (not shown) running through an inside portion of the handle 336 having a raised thread and an inverted thread, wherein a first direction of the raised thread is inverse to a second direction of the inverted thread. Furthermore, the handle 336 includes a position ring 342 located proximate a position indicator 334, the position ring 342 and the position indicator 344 each having one or more bevel greats connecting the position ring 342 to the position indicator 344. In an embodiment, the position indicator 344 is located proximate the knob 338. In certain embodiments, and as will be discussed further herein, the bevel gears of the position ring 342 rotate the bevel gears of the position indicator 344, and thus the position indicator 344, clockwise or counterclockwise to signify the curvature of the deflectable distal region 340. In some embodiments, the steerable actuation mechanism includes the rotation of the knob 338 by a user. In some embodiments, as shown in
In some embodiments, during use, a dilator may be inserted within the steerable sheath 330 for use therewith. In some embodiments, the dilator may include a flexible intermediate region that corresponds to the deflectable distal region 340 of the steerable sheath 330. In certain embodiments, this enables the steerable sheath 330 to reach its allowable range of curvatures or deflection upon actuation as minimal resistance is introduced by the dilator. In some embodiments, this enables the steerable sheath 330 to position the distal end region of the dilator at a desired target location within a region of tissue such as at a desired puncture location or site to enable the distal end region of the dilator to subsequently advance through to, for example, dilate the puncture site. In some embodiments, a puncture wire is configured to advance through the steerable sheath 330. In other further embodiments, a medical therapy device may be configured to advance through the steerable sheath 330. In still other embodiments, the medical therapy device is an ablation catheter.
Additionally, as shown, the direction of the raised thread 451 and the direction of the inverted thread 452 are inverse of each other. Furthermore, while the raised thread 451 includes a positive thread that protrudes from the slider 450 as it rotates around the slider 450, the inverted thread 452 has a negative thread that cuts into the slider 450 as it rotates around the slider 450. In some embodiments, the raised thread 451 and the inverted thread 452 have different thread pitches. In certain embodiments, the raised thread 451 has a lower pitch than the inverted thread 452. Both the raised thread 451 and the inverted thread 452 are spiral in nature. In certain embodiments, the pitch ratio of the raised thread 451 to the inverted thread 452 is 4:1. Thus, in other words, the raised thread 451 rotates around the slider 450 four times as the inverted thread 452 completes one rotation around the slider 450.
In some embodiments, the slider 550 fits into and is connected to the knob 338, as depicted in
Furthermore, in a specific example, the rotation of the knob 338 is converted into a deflection of the steerable sheath 530 via a slide assembly (not shown). Generally, in some embodiments, the knob is rotatably coupled to a housing within the handle 536. In certain embodiments, the knob is co-operatively engaged with the slide assembly which is housed within a lumen defined by the housing of the handle 536. In a specific example, the knob is threadedly (i.e., the raised thread 551 and the inverted thread 552) engaged with the slide assembly. In one embodiment, the rotation of the knob causes a corresponding linear translation of the slide assembly within the lumen of the housing. This translation of the slide assembly is converted into a tensioning of the pair of pull wires coupled to the slide assembly and thereby resulting in a deflection of the sheath 530.
More specifically, in certain embodiments, the slider assembly is coupled to respective proximal ends of the pull wires that extend substantially along the length of the steerable sheath 530. A distal end (not shown) of each of the pull wires is coupled to a distal portion of the steerable sheath 530. In some embodiments, the rotation of the knob in one direction causes the slide assembly to translate proximally within the housing of the handle 536 pulling one of the pull wires to deflect the sheath 530 in a first direction, whereas the rotation of the knob in an opposing direction causes the slide assembly to translate distally within the housing pulling the other of the pull wires to deflect the sheath 530 in a second direction. In one example, in order to allow the slide assembly to separately impart a pulling force on each of the two pull wires, one of the two pull wires is directly coupled to the slide assembly whereas the other of the pull wires is indirectly coupled to the slide assembly via a direction reversing element such a pulley or a pin. In other words, in certain embodiments, a means for of coupling the distal ends of the wires to opposite sides of the slide is included in the handle, whereby motion of the slide in one direction will apply tension to one wire while motion of the slide in the other direction will apply tension to the other wire.
In some embodiments, the pull wires comprise a metal. More specifically, in one example, the wires comprise stainless steel. In some embodiments, the wires comprise a drawn 300-series stainless steel wire. In some embodiments, at least one of the pull wires comprise a round wire. In other embodiments, at least one of the pull wires comprise a flat wire which may be a rectangular wire. In one specific embodiment, the wires comprise stainless steel 304V. In one example, wires have a cross-section of about 0.004″×0.015″. In another example, wires have a cross-section of about 0.004″×0.012″.
In some embodiments, in use, the sheath 530 may be inserted within the vasculature of a patient's body and advanced to a target location. The handle 536 may then be manipulated to allow the user to deflect a distal portion of the sheath 530 in the desired direction. In one broad embodiment, a rotational mechanism is provided that allows rotational movement of the knob in one direction to allow longitudinal movement of the slide assembly in one direction within the inner housing (away from a neutral or starting position) to place one of the pull wires in tension. This allows the sheath 530 distal end to be deflected in a first direction. Whereas, in other embodiments, rotation of the knob in a second direction releases the tension in that pull wire and allows the sheath 530 to return to its neutral position. In other embodiments, further rotation of the knob in the second direction allows the slide assembly to translate linearly or longitudinally in the other (opposing) direction within the handle 536 allowing the other of the two pull wires to be placed in tension. This allows the sheath distal end to be deflected in a second direction.
Additionally, as the user rotates the knob clockwise or counterclockwise depending on the desired direction of curvature of the deflectable distal region, the raised thread 551 translates the rotation of the knob to a linear movement (i.e., up and down) of the slider 550. Thus, the raised thread 551 translates a rotation of the knob to a linear movement of the slider 550. In turn the inverted thread 552 translates the linear movement of the slider 550 to a rotational movement of the position ring 542. This is possible since as disclosed above, in some embodiments, the position ring 542 is connected to the inverted thread 55 via a connector tab (not shown). Because of the connector tab, the linear movement of the slider 550 in turn rotates the position ring 542 through the inverted thread. Since the position ring 542 includes bevel gears that are connected to the bevel gears of the position indicator 544, when the position ring 542 is rotated by the inverted thread 552, this in turn rotates the position indicator 544 clockwise or counterclockwise. Thus, in certain embodiments, the rotational movement of the position ring 542 rotates the position indicator 544. Furthermore, in some embodiments, this mechanism allows the position indicator 544 to provide a visual cue of the steerable sheath 530 deflectable distal region curve direction. This allows the user to more conveniently determine the direction of the deflectable distal portion of the steerable sheath 530 and understand the amount of curve of the deflectable distal portion.
In some embodiments, the consideration of the pitch of the raised thread 551 and the inverted thread 552 and the size of the bevel gears on the position ring 542 and the position indicator 544 allows for the position of the position indicator 544 to match with the curve angle of the deflectable distal region the steerable sheath 530. In some embodiments, the diameter of the slider 550 is between 6 mm to 10 mm. In certain embodiments, the diameter of the slider 550 is 8.97 mm. In some embodiments, the slider 550 may travel in a linear direction between 10 mm to 20 mm. In certain embodiments, the slider 550 may travel in a linear direction between 13 mm to 18 mm. In some embodiments, the pitch of the raised thread 551 is between 10 mm to 15 mm. In other embodiments, the pitch of the raised thread 551 is between 12 mm to 13 mm. In certain embodiments, the pitch of the raised thread 551 is 12.7 mm. In certain embodiments, the pitch ratio of the raised thread 551 to the inverted thread 552 is 4:1. In some embodiments, the pitch of the inverted thread 552 is between 45 mm to 55 mm. In certain embodiments, the pitch of the inverted thread 552 is 50.8 mm. In some embodiments, one full pitch translates to a 90 degree turn of the position indicator 554. Thus, in other embodiments, two full pitches translate to a 180 degree turn of the position indicator 554. In some embodiments, the pitch ratio may be adjusted based on the desired application and/or procedure.
Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof.
The present application claims priority to U.S. Provisional Application No. 63/591,497, filed Oct. 19, 2023, the entire disclosure of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63591497 | Oct 2023 | US |
