Flexible cannula

Abstract

A catheter system includes an elongated cannula that is flexible along a first section that extends along a majority of its length. The cannula has a rigid, distal region that is less flexible than the first section. An anchor assembly is configured to be secured to a patient and to the elongated cannula. The anchor assembly has a patient anchor region that secures to a patient and that has an internal lumen sized and shaped to receive the cannula. The anchor assembly further has a cannula securement region that removably secures to a portion of the cannula.

Description

VIA EFS Attorney Docket No. 060236-526001 WO Date of Filing: March 25, 2026 Customer No. 30623FLEXIBLE CANNULACROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Patent Application No. 63 / 778,768, filed on March 27, 2025, entitled “FLEXIBLE CANNULA”, the contents of which is hereby incorporated by reference herein in its entirety.BACKGROUND

[0002] Cannulas are thin tubes that are inserted into a patient’s body such as to deliver therapeutics into the body or aspirate fluid from the body. A typical cannula may be constructed from one or more rigid materials so that the cannula can be moved along a predetermined, straight trajectory into the patient. This permits a user to target the cannula trajectory toward a specific location in the anatomy. A portion of the cannula not inserted into the body extends outside of the body. In the case of a rigid cannula, this means that a section of stiff tubing may be protruding for some distance such as in an undesirable position outside the body. This can be problematic for a variety of reasons, including potential device breakage / damage, inadvertently “bumping” the device out of position, or other possible interaction with the patient that may cause injury.

[0003] If the cannula is instead constructed from one or more flexible materials, the cannula can be bent or curved along a trajectory that remains flush against the outside the patient’s body. However, the flexible material may not have adequate column strength and rigidity to ensure it follows the desired trajectory (especially when traveling through tissue).SUMMARYAttorney Docket No. 060236-526001 WO

[0004] Disclosed is a cannula configuration and associated workflow that enables a cannula to be inserted to a specific location, while also being flexible enough to bend and remain flush against the outside of the body.

[0005] In one aspect, there is disclosed a method of using a cannula, comprising: securing a cannula anchor to a body of a patient; inserting a distal region of the cannula through the cannula anchor into the body of a patient; and securing a proximal region of the cannula to the cannula anchor.

[0006] In another aspect, there is disclosed a catheter system, comprising: an elongated cannula, the cannula being flexible along a first section that extends along a majority of its length and having a rigid, distal region that is less flexible than the first section; and an anchor assembly that is configured to be secured to a patient and to the elongated cannula, the anchor assembly having a patient anchor region that secures to a patient and that has an internal lumen sized and shaped to receive the cannula, the anchor assembly further having a cannula securement region that removably secures to a portion of the cannula.

[0007] The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 shows a side view of an example flexible cannula.

[0009] Figures 2 and 3 show an anchors assembly for the cannula.

[0010] Figure 4 shows an example peel away guide tube.Attorney Docket No. 060236-526001 WO

[0011] Figures 5 and 6 show an alternate example of an anchor assembly.

[0012] Figures 7 and 8 show another alternate example of an anchor assembly.

[0013] Figures 9 and 10 show the anchor assembly positioned within bone.DETAILED DESCRIPTION

[0014] Before the present subject matter is further described, it is to be understood that this subject matter described herein is not limited to particular embodiments described, as such may of course vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. Unless defined otherwise, all technical terms used herein have the same meaning as commonly understood by one skilled in the art to which this subject matter belongs.

[0015] Figure 1 shows a side view of an example cannula 102 formed of an elongated, tubular body having an internal lumen. The cannular has at least one distal opening and at least one proximal opening that both communicate with the internal lumen. The flexible cannula is a long device that is configured to be inserted into a patient such as via an access site through the patient’ skin. The internal lumen is configured to deliver therapy or aspirate fluids for the patient.

[0016] With reference still to Figure 1 , the cannula 102 has a distal end 105 and a proximal end 108. The distal end 105 inserts into the patient while the proximal end remains outside the patient. A distal tip of the cannula 102 is formed of a thin capillary tube 110 that forms a distal opening where fluid enters and / or exits the cannula 105. The cannula 102 may have at least one stepped increase 115 in outer diameter (OD) such that the outer diameter at the stepped increase 115 is sized and shaped to form a seal with tissue and prevent fluid backflow along anAttorney Docket No. 060236-526001 WOouter surface of the cannula. The cannula 102 may also have a ramped increase 120 in OD. The ramped increase 120 is configured to increase strength of the cannula and further prevent fluid backflow. The cannula 102 further includes a short distal segment 125 that includes an external, rigid structure. The cannula 102 further includes a longer segment 130 (relative to the segment 125) of semi-flexible tubing such that the segment 130 is more flexible than the segment 125. The cannula 102 further includes short proximal segment 135 where the inner lumen is accessible (such as via an opening) to attach syringes or other accessories. The segment may be positioned external to the body during use. In an implementation, the cannula is flexible along a first section that extends along a majority of its length and has a rigid, distal region that is less flexible than the first section. The cannula along the first section can be at least partially ceramic along a length of 10 mm, or along a length of 5 mm to 40mm. The distal region can be a length of 10mm to 30mm distally beyond the first section.

[0017] In an example implementation, the entire cannula 102 is semiflexible except for short rigid segment at the distal end of the cannula 102. The device is configured such that it is flexible enough to be bent, but stiff enough that it can retain its shape such as while being pushed through a guide tube.

[0018] It should be appreciated that the cannula 102 can vary in configuration. For example, the size, shape, position and / or quantity of steps or ramps can vary such as to vary the outer diameter at the distal end of the cannula. The canula may or may not have a rigid segment at the distal end. The cannula inner lumen may be constructed from a single, continuous tubing or may have several discrete segments of tubing attached to form the inner lumen. The cannula may have an exposed segment of inner lumen tubing at the proximal end (or any location) or may be preassembled with other accessories such as a Luer fitting, therapeutic reservoir, etc. The cannula may be constructed with multiple tubes and components or may be formed of a single body tube.

[0019] Figures 2 and 3 show an example implementation of a cannula anchor assembly or anchor 205 that is configured to secure a position of the cannulaAttorney Docket No. 060236-526001 WO120 relative to the patient’s body. The anchor 205 is secured to the body at a cannula access site of the patient such as by securing the anchor 205 to skin and / or bone. The anchor 205 has an elongated patient anchor region (which can be a bone screw for example) that secures the anchor 205 to a patient. In an implementation, at least a portion of the anchor is a threaded region 210 that flares or otherwise expands outward to form into an enlarged base 215. The base 215 is shown as having a round shape although the shape may vary. The base 215 supports or is coupled to a cannula securement region configured to secure to a cannula. The securement region can be for example a cupped receptor 220 (or a portion thereof) that can have a tulip shape for example. The cannula anchor 205 may include a cover that is placed over the receptor 220, as described further below. The receptor 220 is formed of an outer rail or annular wall 225 that forms or surrounds a bowl 230 having a central opening that communicates with an internal lumen of the threaded region 210. The bowl 230 can have a variety of shapes including a concave shape, a funnel shape, an inclined surface shape, a series of inclined surfaces, or any structure or shape that guides an inserted cannula 102 toward the central opening. The cannula 102 can extend through the internal lumen of the threaded region 210 and exit the anchor 205 via the opening in the bowl 230.

[0020] The wall 225 of the anchor 205 has one or more guides and / or retainers such as ridges or notches 235 that are each sized and shaped to receive at least a portion of the cannula 102 such as in a press fit fashion, as shown in Figure 3. The notches 235 are positioned at a top edge of the wall 225. The notches 235 may be interspersed along the length of the annular wall 225 such as at fixed or variable intervals. In this manner, the notches 235 serves as holders and / or guides that can be used to hold and / or guide a trajectory of the proximal region of the cannula 102 as it exits the anchor 205.

[0021] Figure 5 shows another implementation of the anchor assembly or anchor 205 in an exploded state. Figure 6 shows the anchor 205 of Figure 5 in an assembled state. The anchor 205 includes a bone screw 505, a deformable or malleable element such as a sleeve 510, the receptor 220, and a cover 515. The bone screw 505 has a threaded shank 520 configured to be threaded into boneAttorney Docket No. 060236-526001 WOand / or other anatomical tissue to secure the anchor 205 to the patient. The bone screw 505 may have an upper head that may be threaded and may vary in shape. The receptor 220 can be a cylindrical body having a threaded inner surface that couples in a threaded manner with an outer thread at the upper hed of the bone screw 505. When the receptor 220 and the threaded head are coupled to one another, an internal lumen of the receptor 220 coaxially aligns with an internal lumen through the threaded head and shank 520 of the bone screw 505. In the implementation of Figure 5 and 6, the receptor 220 may have an internal lumen and / or a bowl (as in the prior implementation.) In either case, the internal lumen or bowl can communicate with an internal lumen of the bone screw 505 when coupled thereto.

[0022] The sleeve 510 is co-axially positionable within the receptor 220 and the threaded head of the bone screw. The sleeve 510 fits around and receives the cannula 102 when the cannula is coupled to the anchor 505. The sleeve 510 is malleable such that it may provide strain relief when the cannula 102 bends while positioned through the anchor 205. The sleeve 510 may also be adapted to seal onto and around the cannula 102 although a seal is not necessary. The receptor 220 removably couples to the upper head of the bone screw 505 such as via a threaded connection to secure the sleeve therein as well as to secure the cannula when positioned through the receptor and bone screw.

[0023] The cover 515 is sized and shaped to fit on and at least partially over the receptor 220 such as via a press fit or via a threaded connection. The cover 515 can be for example a cap with an upper base 525 and a downwardly extending, annular wall 530 sized and shaped to receive an outer region of the receptor 220 therein. The receptor 220 and the cover 515 may have complementary structures that engage one another to secure the cover 515 to the receptor. For example, an outer surface of the receptor 220 may have an outer slot that lockingly engages with a protrusion on an inner wall of the cover 515 when the cover 515 is coupled to the receptor 220 and twisted thereto. The configuration for securing the cover 515 to the receptor 220 can vary.Attorney Docket No. 060236-526001 WO

[0024] With reference still to Figure 5, the annular wall 530 of the cover 515 has a slot 535 or other opening that is sized and shaped to receive therethrough the cannula. As shown in the assembled view of Figure 6, when the cover 515 is coupled to the receptor 220, the slot 535 provides a passageway for the cannula 102 to pass into the receptor 220, as described further below. The slot 353 can be an elongated opening that extends through the annular wall 530 with an upper end that is enclosed or bounded by the upper base 252 and an upper end that is open or unenclosed such that the cannula 102 can slide upward into the slot 353 or downward out of the slot via the open end of the slot. The slot 535 may vary in shape. In an implementation, the slot 535 is elongated end extends along an entire height of the wall 530 and has a width that snugly fits a width or diameter of the cannula 102. In another implementation, the width of the slot 535 is barely larger or much larger than a diameter of the cannula 102.

[0025] Figures 7 and 8 show another implementation of the anchor 205 in exploded and assembled states. In this implementation, the bone screw 505 has driving structure such as a hexagonal head 605 that can be used to drive the bone screw 505 into the anatomy. The sleeve 510 is shown positioned within an internal lumen of the bone screw 505 such that it can receive the cannula 102 therein (in a sealed or non-sealed relationship with the cannula 102 extending into the receptor and then into the bone sleeve 510 and bone screw 505.

[0026] Figure 9 shows the anchor 205 positioned in bone such that the shank 520 of the bone screw 505 is secured into bone. The cover 515 is coupled to the receptor 220 such that the cannula 102 extends through the cover’s slot 535 into the receptor 220. The slot 535 provides an opening into an internal region of the receptor 220 such that the cannula accesses the internal lumen of the receptor via the slot 535. The upper end of the slot 535 is positioned above an upper edge of the annular wall of the receptor 220 so that an opening into the receptor is formed via the upper end of the slot 535. Figure 10 shows the anchor 205 without the cover.

[0027] The anchor may vary in configuration. The anchor may be secured by screwing it into bone. It may also use separate bone screws, adhesives,Attorney Docket No. 060236-526001 WOsutures, bandages or a variety of other affixation means. The anchor may secure the cannula in place using a deformable or malleable element, such as a collet, grommet, O-ring, or other deformable element-, as described below. The malleable element may vary in shape and can be, for example, an O-ring, a toroidal shape, square shape, cylindrical shape, or any other shape. Alternatively, the anchor may use other securement modes such as one or more clamps, bends, adhesives, foams, compression means, etc. The anchor may use a funnel and grooves to facilitate bending the cannula towards the skin as described herein. Or it may also use other geometry including grooves without a funnel, ramps, or a clamshell enclosure. The anchor cap may be a separate component or may be incorporated into the anchor device. It may be manipulated by hand or may require tools (e.g., screwdriver) to secure the cap to the anchor, which may also compress the deformable element, such as an O-ring, in the anchor. The anchor may be a single, monolithic component or may be formed of multiple bodies attached together, such as bone screw attached to a compression cap.

[0028] In an example implementation, the anchor 205 is secured to the body via threading on the threaded region 210 that allows it to be screwed into bone. The anchor can be driven into the bone by engaging a driving device (such as a wrench or other device) with a mating surface of the anchor wherein the mating surface can be internal or external to the bone anchor. The cannula 102 is inserted through the anchor such as through a lumen in the threaded region 210. Once the cannula 102 is positioned in a desired location and orientation, it is secured relative to the anchor so that it will not move. In an implementation, the anchor 205 contains or is at least partially formed of a deformable element, such as an O-ring, that can be malleably compressed into a desired shape such that it deforms to constrain the cannula. The anchor 205 also holds the cannula 102 in a desired position as it exits the body of the anchor. In the illustrated implementation, the bowl 239 has a funnel shape that facilitate bending the cannula so that it exits the body approximately parallel to and adjacent the skin. The anchor 205 can also include a cap that removably couples to the anchor. The cap can cover and constrain the cannula once the cannular in the desired location.Attorney Docket No. 060236-526001 WO

[0029] In an implementation of a method of use, the cannula 102 and the anchor 205 are configured to couple to and interact with an elongated cannular guide tube through which the cannula 102 is inserted. The guide tube can be inserted through the anchor 205 such as by inserting the guide tube into the lumen of the anchor 205. The canula 102 is then inserted into the guide tube while the guide tube is coupled to the anchor. In an example implementation, the guide tube is a peel away sheath (PAS) manufactured by ClearPoint Neuro, Inc.

[0030] Figure 4 shows an example implementation of a peel away sheath 405, which is formed of a semi-flexible tube 410 that is inserted into the anchor 204 using several accessories, including a rigid stylet 415 that extends coaxially through the tube 410. With the stylet in place, the guide tube is rigid enough to remain straight so it can be advanced along a desired trajectory. The guide tube is positioned to approach the target location, but stopped short of the target location such that it does not actually touch the location. Once the assembly is in the desired position, the stylet 415 is removed such as by pulling or otherwise withdrawing the stylet from a proximal side. The PAS then acts as a guide tube for the cannula.

[0031] The cannula 102 can be pushed through the guide tube 410 to the target site. The guide tube 410 maintains a desired trajectory so that the position of the cannula 102 is accurate when delivered through the tube 410. The guide tube 410 has a sufficiently large inner diameter such that the cannula 102 can pass through with minimal friction, but small enough inner diameter that the cannula cannot deflect or buckle. Once the cannula 102 is in the desired position, then the guide tube may be removed and the cannula 102 can be secured in the anchor 205.

[0032] The guide tube can vary in configuration. The guide tube may be a peel away sheath as described or may be a traditional (non-peelable) tube. The guide tube may be semi-flexible or may be rigid. The guide tube may be removed after the cannula is in the desired position. Alternatively, the guide tube may be left in place with the cannula. If the guide tube is left in place, it may be configured such that it does not extend outside of the patient’s body. A specific guide tube length may be used. The appropriate length may be selected from a list of available options.Attorney Docket No. 060236-526001 WOOtherwise, it may be trimmed to length. The guide tube workflow may include a hub, dock, or other features that allow it to be used with surgical equipment such as a navigation frame. It may also utilize a lock feature that secures the cannula in place while the guide tube is removed.

[0033] Any of the components described herein may be designed and constructed such that it is magnetic resonance (MR) safe or MR conditional.

[0034] Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and / or interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise.

[0035] While this specification contains many specifics, these should not be construed as limitations on the scope of an invention that is claimed or of what may be claimed, but rather as descriptions of features specific to particular embodiments. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or a variation of a sub-combination. Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or thatAttorney Docket No. 060236-526001 WOall illustrated operations be performed, to achieve desirable results. Only a few examples and implementations are disclosed. Variations, modifications and enhancements to the described examples and implementations and other implementations may be made based on what is disclosed.

Claims

Attorney Docket No. 060236-526001 WOCLAIMS1. A catheter system, comprising:an elongated cannula, the cannula being flexible along a first section that extends along a majority of its length and having a rigid, distal region that is less flexible than the first section;an anchor assembly that is configured to be secured to a patient and to the elongated cannula, the anchor assembly having a patient anchor region that secures to a patient and that has an internal lumen sized and shaped to receive the cannula, the anchor assembly further having a cannula securement region that removably secures to a portion of the cannula.

2. The catheter system of claim 1 , wherein the elongated patient anchor region is an elongated body having a straight shape.

3. The catheter system of claim 1 , wherein elongated patient anchor region is sized and shaped to receive a guide tube that receives the cannula.

4. The catheter system of claim 3, wherein the guide tube peels away from the cannula.

5. The catheter system of claim 1 , wherein the cannula securement region comprises a bowl-shaped body.

6. The catheter system of claim 5, wherein the bowl-shaped body comprises a funnel.

7. The catheter system of claim 6, wherein the cannula securement region further comprises an annular wall that includes at least one notch sized and shaped to securely receive the cannula.

8. The catheter system of claim 1 , wherein the anchor assembly includes malleable element configured to provide strain relief to the elongated cannula when the cannula positioned through the anchor assembly.

9. The catheter system of claim 1 , wherein the malleable element seals to the cannula.Attorney Docket No. 060236-526001 WO10. The catheter system of claim 1 , wherein the malleable element is an O-ring, a collar, a square ring, or a grommet.

11. The catheter system of claim 1 , wherein the elongated patient anchor region is threaded.

12. The catheter system of claim 1 , wherein the elongated patient anchor region comprises a bone screw that secures to bone.

13. The catheter system of claim 12, wherein the bone screw has a threaded shank.

14. The catheter system of claim 13, further comprising a cap that secures to the anchor assembly wherein the cap is formed of an upper base and a downwardly extending, annular wall sized and shaped to receive an outer region of the securement region.

15. The catheter system of claim 14, wherein the cap has a slot is sized and shaped to receive therethrough the cannula.

16. The catheter system of claim 15, wherein the slot extends through the annular wall of the cap.

17. A method of using a cannula, comprising:securing a cannula anchor to a body of a patient;inserting a distal region of the cannula through the cannula anchor into the body of a patient; andsecuring a proximal region of the cannula to the cannula anchor.

18. The method of claim 17, wherein the cannula anchor is secured to the body of the patient by attaching an anchor region of the cannula anchor to the patient.

19. The method of claim 18, wherein the anchor region is threaded.

20. The method of claim 19, wherein the anchor region attaches to a bone of the patient.Attorney Docket No. 060236-526001 WO21. The method of claim 17, wherein the proximal region of the cannula is secured to the cannula anchor by inserting the proximal region of the cannula into a notch in the cannula anchor.

22. The method of claim 17, wherein the cannula is inserted into a funnel region of the cannula anchor.

23. The method of claim 17, further comprising inserting a guide tube into the cannula anchor and then inserting the cannula through the guide tube.

24. The method of claim 17, wherein the cannula anchor defines a trajectory of the cannula.

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