Catheter with electromagnetic navigation coil

Abstract

Medical devices with electromagnetic navigation sensors and free floating conductor wires are described herein. In some variations, a medical device may include an elongated member comprising an inner structure, an outer structure arranged circumferentially around the inner structure, and a channel defined by an outer surface of the inner structure and an inner surface of the outer structure. The medical device may further include an electromagnetic navigation coil wrapped circumferentially around the inner structure and arranged between the inner structure and the outer structure, and at least one conductor wire extending from the navigation coil and free floating within the channel along the elongated member.

Description

CATHETER WITH ELECTROMAGNETIC NAVIGATION COIL

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 586,819, filed September 29, 2023, the entire content of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The present technology relates to a catheter with an electromagnetic navigation coil.BACKGROUND|0003] Electromagnetic (EM) navigation is a common form of surgical navigation for catheters and other medical devices. For example, a catheter can include one or more EM navigation sensors, each of which can be localized with respect to a magnetic reference field. The signal data from the EM navigation sensors can be translated into positional information of the medical device in which the EM navigation sensors are placed.

[0004] One example of an EM navigation sensor is a wired induction sensor, which includes an EM coil with a twisted pair of conductor wires for signal transmission. However, EM coils and conductor wires can be extremely fragile, especially in applications in which a smaller wire diameter is desirable to reduce the size of a catheter. For example, in a catheter having an EM coil and conductor wires that extend along the length of the catheter, there is a risk of the conductor wires undergoing strain-induced fracture as the catheter is bent, torqued, and / or otherwise navigated in a patient body. Such failure of the conductor wires is undesirable, as it renders the EM navigation sensor unusable. Thus, there is a need for a new and improved catheter with an EM navigation coil.SUMMARY

[0005] The subject technology is illustrated, for example, according to various aspects described below, including with reference to FIGS. 1A-13. Various examples of aspects of the subject technology are described as numbered clauses (1, 2, 3, etc.) for convenience. These are provided as examples and do not limit the subject technology.

[0006] Example AL A medical device comprising:an elongated member comprising an inner structure, an outer structure arranged circumferentially around the inner structure, and a channel defined by an outer surface of the inner structure and an inner surface of the outer structure; an electromagnetic navigation coil wrapped circumferentially around the inner structure and arranged between the inner structure and the outer structure; and at least one conductor wire extending from the navigation coil and free floating within the channel along the elongated member.[00(17 J Example A2. The device of example A 1 , wherein a distal portion of the inner structure and a distal portion of the outer structure are coupled along a distal joining region.

[0008] Example A3. The device of example A2, wherein the distal joining region is entirely distal to the navigation coil.[0009| Example A4. The device of example A2, wherein the distal joining region overlaps with at least a portion of the navigation coil.|0010[ Example A5. The device of any one of examples A1-A4, wherein an intermediate portion of the inner structure and the intermediate portion of the outer structure are coupled along at least one or more intermediate joining regions.[00.11] Example A6. The device of any one of examples A1-A5, wherein an entire length of the inner structure and an entire length of the outer structure are continuously coupled along a continuous joining region.|0012] Example A7. The device of any one of examples A1-A6, wherein the outer structure comprises an outer tubular member and the inner structure comprises an inner tubular member arranged coaxially within the outer tubular member.

[0013] Example A8. The device of any one of examples A1-A7, wherein at least a portion of the channel comprises an annular lumen.

[0014] Example A9. The device of any one of examples A1-A7, wherein at least a portion of the channel comprises an arcuate lumen.

[0015] Example A10. The device of any one of examples A1-A7, wherein at least a portion of the channel comprises a helical lumen.

[0016] Example Al l. The device of any one of examples A1-A10, wherein an outer surface of the inner structure comprises an annular recess and the navigation coil is in the annular recess.

[0017] Example A12. The device of any one of examples Al-Al l, wherein an outer surface of the inner structure comprises a recess forming a wall of the channel.[O018| Example A13. The device of any one of examples A1-A12, further comprising a flexible strain relief material arranged over a portion of the navigation coil and a portion of the at least one conductor wire.

[0019] Example A14. The device of any one of examples A1-A13, wherein the medical device comprises a plurality of navigation coils.

[0020] Example A15. The device of example A14, wherein the elongated member comprises a plurality of channels defined by the outer surface of the inner structure and the inner surface of the outer structure. 0021 Example A16. The device of example A15, further comprising a plurality of conductor wires, wherein each conductor wire is coupled to a respective navigation coil and extending along the elongated member with free movement within a respective channel.

[0022] Example A17. The device of any one of examples A1-A16, wherein the at least one conductor wire is lubricated.[00231 Example A 18. The device of any one of examples Al -A 17, wherein the medical device is a catheter.

[0024] Example A19. The device of any one of examples A1-A18, wherein the medical device is a delivery catheter.

[0025] Example A20. The device of any one of examples A 1-Al 9, wherein the medical device is a delivery catheter for a cardiac pacemaker lead.BRIEF DESCRIPTION OF THE DRAWINGS(0026] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on illustrating clearly the principles of the present disclosure.

[0027] FIG. 1A is an illustrative schematic of an example catheter with an electromagnetic (EM) navigation sensor in accordance with the present technology. FIG. IB is an illustrative detailed schematic of the example catheter of FIG. 1 A.

[0028] FIG. 2A is an illustrative schematic of a portion of an example catheter with an EM navigation coil in accordance with the present technology. FIG. 2B is a cross- sectional schematic of the catheter of FIG. 2 A taken along line 2B:2B.[0029 FIG. 3A is an illustrative schematic of a portion of an example catheter with an EM navigation coil in accordance with the present technology. FIG. 3B is a cross- sectional schematic of the catheter of FIG. 3 A taken along the line 3B:3B.

[0030] FIG. 4A is an illustrative schematic of a portion of an example catheter with an EM navigation coil in accordance with the present technology. FIGS. 4B-4E are cross- sectional schematics of the catheter of FIG. 4A, taken along the lines 4B:4B, 4C:4C, 4D:4D, and 4E:4E, respectively.

[0031] FIG. 5A is an illustrative schematic of a portion of an example catheter with an EM navigation coil in accordance with the present technology. FIGS. 5B-5E are cross- sectional schematics of the catheter of FIG. 5A, taken along the lines 5B:5B, 5C:5C, 5D:5D, and 5E:5E, respectively.

[0032] FIG. 6A is an illustrative schematic of a portion of an example catheter with an EM navigation coil in accordance with the present technology. FIGS. 6B-6E are cross- sectional schematics of the catheter of FIG. 6A, taken along the lines 6B:6B, 6C:6C, 6D:6D, and 6E:6E, respectively.

[0033] FIG. 7 is an illustrative schematic of a portion of an example inner structure with an EM navigation coil in accordance with the present technology.

[0034] FIG. 8 is an illustrative schematic of an example inner structure of a catheter in accordance with the present technology.

[0035] FIG. 9A is an illustrative schematic of a portion of an example catheter with multiple EM navigation coils in accordance with the present technology. FIGS. 9B and 9C are cross-sectional schematics of the catheter of FIG. 9A, taken along the lines 9B:9B and 9C:9C, respectively.[0036| FIG. 10 is an illustrative flowchart of an example method of making a catheter with an EM navigation coil in accordance with the present technology.J0037J FIG. 11 is an illustrative flowchart of an example method of making a catheter with an EM navigation coil in accordance with the present technology.

[0038] FIG. 12 is an illustrative flowchart of an example method of making a catheter with an EM navigation coil in accordance with the present technology.

[0039] FIG. 13 is an illustrative flowchart of an example method of making a catheter with an EM navigation coil in accordance with the present technology.DETAILED DESCRIPTION

[0040] The present technology relates to medical devices with EM navigation coil(s) and free floating conductor wire(s). Some variations of the present technology, for example, are directed to a catheter with an EM navigation coil and free floating conductor wire(s). Other variations of the present technology may relate to other medical devices whose position is desirable to track within a patient (e.g., a medical device that is navigated or otherwise placed in a patient body). Specific details of several variations of the technology are described below with reference to FIGS. 1-12.

[0041] Generally, in some variations a medical device may include a member having an inner structure, an outer structure arranged circumferentially around the inner structure, and a channel defined by an outer surface of the inner structure and an inner surface of the outer structure. The medical device may further include an EM navigation coil wrapped circumferentially around the inner structure and arranged between the inner structure and the outer structure, and one or more conductor wires extending from the navigation coil. The conductor wires may be free floating within the channel along the member.

[0042] In some variations, the medical device may be a catheter with an elongated member. The catheter may be, for example, a delivery catheter that is navigated to a target location (e.g., treatment location for a treatment device such as a pacemaker lead, stent, and / or other implant), where the EM navigation coil provides sensor signals that are carried by the conductor wires for analysis (e.g., carried proximally along the elongated member to a catheter hub or handle). In other examples, the catheter may include a treatment device at its distal end. However, while the present technology is primarily described with respect toa catheter, it should be understood that the present technology is additionally or alternatively applicable to other medical devices, such as endoscopes (e.g., bronchoscopes, ureteroscopes, cystoscopes, colonoscopes, etc.), probes, or leads (e.g., stimulation leads).

[0043] Due to the free floating nature of the conductor wires, the conductor wires may be able to freely move within the channel in response to induced strain (e.g., pushing, pulling, twisting, etc. of the medical device), thereby reducing the risk of strain-induced fracture and increasing the overall reliability of the navigation coil sensor when the medical device is navigated to a target location. Other features of the medical device may additionally or alternatively reduce the strain on the navigation coil and / or conductor wires, as further described herein.I. Catheter Device[0044 As shown in FIG. 1A, a catheter 10 or other medical device may include a proximal catheter portion lOp and a distal catheter portion lOd. During operation of the catheter 10, the distal catheter portion lOd may be insertable in a patient body and navigated to a target location, while at least a portion of the proximal catheter portion lOp may be located outside the patient body. The distal catheter portion lOd may include an EM navigation coil 110, such as at or near a distal tip of the catheter 10. Signals from the navigation coil 110 may be carried by one or more conductor wires that travel from the navigation coil 110 proximally toward the proximal catheter portion lOp. In some variations, the catheter 10 may carry one or more manipulation members (e.g., pull wires) for aiding with navigation of the catheter 10 in the patient body. In some variations, the catheter 10 functions as a delivery catheter for a treatment device, such as a pacemaker lead. For example, in some variations the catheter 10 may include an elongated member with an inner lumen that is configured to carry a pacemaker lead therethrough.

[0045] In some variations, the proximal catheter portion lOp may be coupled to a catheter hub 20, which may include one or more ports (not shown) to aid with operation of the catheter 10, such as for providing electrical communication with the conductor wires associated with the navigation coil 110, fluid irrigation, and / or the like. The hub 20 may additionally or alternatively function as a handle for allowing user control of one or more manipulation members.

[0046] As shown in FIG. IB, the catheter 10 may include an elongated member having an inner structure 120 and an outer structure 130. In some variations, the inner structure 120 may be an inner layer of the elongated member, and the outer structure 130 may be an outer layer of the elongated member. For example, the inner structure 120 may include a tubular member including one or more of a liner material (e.g., PTFE liner), a braid, and / or other suitable polymer. The inner structure 120 may, in some variations, include a lumen for carrying a device (e.g., treatment device) and / or one or more lumens such as for pull wires, irrigation fluid, and / or the like. Additionally or alternatively, the outer structure 130 may include a tubular member including one or more of a braid, a jacket material, heat shrink and / or the like. In some variations, the inner and outer structures may be coaxial along at least a portion of the length of the catheter 10. For example, the inner structure (e.g., tubular member) may be arranged coaxially within the outer structure (e.g., tubular member). Additionally or alternatively, the inner and outer structures may be radially offset from each other along at least a portion of the length of the catheter 10.[0047 As described above, the catheter 10 may include at least one EM navigation coil 110 that is wrapped around the inner structure 120. The navigation coil may, for example, include copper wire or another suitable material. It should be understood that by being “wrapped” around the inner structure 120, the navigation coil 110 is not necessarily positioned around the inner structure 120 by the physical act of wrapping a wire around the inner structure 120 to form the coil in situ. While in some variations at least a portion of the navigation coil 110 may be formed by wrapping a wire around the inner structure 120, the term “wrapped” may also apply to some variations in which at least a portion of the navigation coil 110 may additionally or alternatively be separately formed (e.g., wrapped or otherwise wound into a coil shape) and then subsequently positioned over and / or around the inner structure 120. In some variations, the catheter 10 may include at least one navigation coil 110 at a distal catheter portion lOd (e.g., at or near the distal tip of the catheter 10). One or more conductor wires 112 (e.g., a twisted pair of conductor wires) may extend proximally from the navigation coil 110 to the hub 20, where signals carried by the conductor wires 112 may be communicated for suitable signal processing for EM navigation purposes. In some variations, the catheter 10 may include multiple navigation coils 110 wrapped around the inner structure 100 at different longitudinal locations along the length of the catheter 10,and each navigation coil 110 may have a respective set of conductor wires 112 for carrying its sensor signals.J0048J In some variations, the conductor wires 112 in a catheter may be loaded into the channel 150 with pre-defined extra length or slack, so as to provide pre-defined strain relief in the conductor wire(s) themselves. The conductor wires 112 may include any suitable material, such as copper wire (e.g., beryllium copper wire).[0049 In some variations, the catheter 10 may be splittable such that when catheter 10 is navigated to a target location, the catheter 10 may be split to expose and deliver a device (e.g., pacemaker lead) at the target location. The split catheter 10 may subsequently be removed from the patient body, while leaving behind the delivered device. In some variations, for example, the inner structure 120 and / or the outer structure 130 may include perforations that can be broken (e.g., tom or cut) to split the catheter. For example, the catheter 10 may include one longitudinal series of perforations that can be broken (e.g., such that the split catheter 10 is “C”-shaped), or multiple longitudinal series of perforations that can be broken (e.g., such that the catheter 10 is split into two or more longitudinal portions). As another example, the catheter 10 may include one or more helical series of perforations that can be broken such that the split catheter 10 is spiralized.

[0050] The inner structure 120 and the outer structure 130 may be coupled to each other at one or more locations. The inner and outer structures may be coupled in any suitable manner, such as through bonding (e.g., with a laser, reflow techniques, potting with an adhesive, etc.) and / or formation through a suitable manufacturing process (e.g., printing or reflowing the outer structure over the inner structure). In some variations, as shown in FIG. IB, in some variations, the inner and outer structures may be coupled along one or more joining regions. For example, the inner and outer structures may be coupled along a distal joining region 140d in the distal catheter portion lOd, where at least a portion of the distal joining region 140d is distal to the navigation coil 110. The distal joining region 140d may be entirely distal to the navigation coil 110, may overlap with a portion of the navigation coil 110 (e.g., partially cover or encase the navigation coil 110), or may overlap with the entire navigation coil 110 (e.g., entirely cover or encase the navigation coil 110). As another example, the inner and outer structures may additionally or alternatively be coupled along a proximal joining region 140p in the proximal catheter portion lOp, such as near or in thehub 20. As another example, the inner and outer structures may additionally or alternatively be coupled along one or more intermediate joining regions between the distal and proximal joining regions, as further described below. In some variations, the inner and outer structures may be continuously coupled (e.g., at least partially circumferentially) to each other along a continuous joining region along all or a significant portion of the catheter length, while in some variations the inner and outer structures may be coupled (e.g., at least partially circumferentially) to each other along one or more discrete joining regions (e.g., distal joining region 140d, intermediate joining region(s), proximal joining region 140p, etc.).|0051| As shown in FIG. IB, the walls of the inner structure 120 and the outer structure 130 may be offset or spaced apart such that the walls of the inner structure 120 and the outer structure 130 define a channel 150 that extends from the navigation coil 110 to the hub 20 of the catheter. The channel 150 functions to provide a space within which the conductor wires 120 for the navigation coil 110 may free float while traversing the catheter 10. For example, the channel 150 may be defined by an outer surface of the inner structure 120 and an inner surface of the outer structure 130. This example is in contrast to a catheter design that includes a third, separate tubular member (e.g., PTFE or PET tubing) arranged between the inner structure and the outer structure and functioning as a secondary lumen, which is characterized as having a high risk of strain-induced fracture of the conductor wires, particularly at the transition point between the navigation coil and the conductor wires and / or where conductor wires pass into the third, separate tubular member. Advantageously, the catheter design such as that shown in FIG. IB where the channel 150 is defined by surfaces of the inner structure and the outer structure (and the navigation coil 110 is wrapped around the inner structure) allows the conductor wires 112 to move when the catheter 10 is bent, twisted, etc., thereby reducing risk of strain-induced fracture of the conductor wires 112. In some variations, the diameter or width of the channel 150 (e.g., as measured between the inner structure 120 and the outer structure 130) is between about the diameter of the conductor wires 112 (e.g., diameter of a single wire, or diameter of a twisted wire pair) and about three times the diameter of the conductor wires 112. For example, in a variation in which the conductor wire or twisted wire pair has a diameter of about 0.0005 inches (about 0.127 mm), the diameter or width of the channel 150 may be about 0.0008 inches (about 0.203 mm).

[0052] Although the channel 150 is shown for illustrative purposes in FIG. IB as an annular lumen for a portion of the length of the inner and outer structures extending between the distal joining region 140d and the proximal joining region 140p, the channel 150 may additionally or alternatively have any suitable shapes. For example, at least a segment of the channel 150 may include an annular cross-section that extends fully circumferentially around the inner structure 120, at least a segment of the channel 150 may include an arcuate cross-section that extends partially circumferentially around the inner structure 120. Additionally or alternatively, at least a portion of the channel may extend longitudinally along the catheter 10 substantially parallel to a longitudinal axis of the catheter, and / or at least a portion of the channel 150 may be helical and spiral around a length of the inner structure 120 along the catheter 10. In some variations, the shape of the channel 150 may be defined at least in part by the location and / or shape of one or more joining regions. Various further examples of joining region(s) and channels are described in further detail herein with respect to the drawings, such as FIGS. 2A-9C.

[0053] FIGS. 2A and 2B are schematic illustrations of a portion of an example catheter 200, which may be similar to catheter 10 except as described below. Similar to the catheter 10 described above with respect to FIGS. 1A and IB, the catheter shown in FIG. 2A may include an inner structure 120, an outer structure 130, and a navigation coil 110 wrapped circumferentially around the inner structure 120. The inner structure 120 and the outer structure 130 may be coupled along a distal joining region 140d, at least a portion of which is distal to the navigation coil 110. Similar to that described above, the distal joining region 140d may be entirely distal to the navigation coil 110, partially overlapping with the navigation coil 110, or entirely overlapping with the navigation coil 110. The inner structure 120 and the outer structure 130 may, in some variations, also be coupled along a proximal joining region near or in the hub 20 (not shown). In this example, the inner structure 120 and the outer structure 130 are uncoupled (e.g., open, not bonded) over a continuous segment of the catheter between the distal joining region 140d and the hub. Along this continuous segment of the catheter, the catheter includes a channel 150 including an annular lumen with a ring-shaped cross-section, as shown in FIG. 2B. One or more conductor wires 112 may traverse the catheter within the channel 150, and configured to free float within the channel 150.

[0054] FIGS. 3 A and 3B are schematic illustrations of a portion of an example catheter 300, which may be similar to any of catheter 10 and catheter 200 except as described below. For example, like the catheter 10, the catheter 300 may include an inner structure 120, and outer structure 130, and a navigation coil 110 wrapped circumferentially around the inner structure 120. The inner structure 120 and the outer structure 130 may be coupled along a distal joining region 140d, at least a portion of which is distal to the navigation coil 110. The inner structure 120 and the outer structure 130 may, in some variations, also be coupled along a proximal joining region near or in the hub 20 (not shown). The inner structure 120 and the outer structure 130 are additionally coupled along an intermediate joining region 140i along a continuous segment of the catheter between the distal joining region 140d and the hub. In some variations, the distal joining region 140d, the intermediate joining region 140i, and / or the proximal joining region may form a continuous joining region along the catheter.

[0055] The intermediate joining region 140i may extend only partially circumferentially around the inner structure 120, thereby leaving uncoupled (e.g., open, not bonded) an arcuate segment of the space between the inner and outer structures. The uncoupled regions of the space between the inner and outer structures may form a channel 150 as an arcuate lumen as shown in FIG. 3B. For example, in some variations, the cross- sectional angular span of the channel 150 and the cross-sectional angular span of the intermediate joining region 140i may be explementary (i.e., sum to about 360 degrees). In some variations, the intermediate joining region 140i may generally have the same or similar cross-section along the length of the catheter, such that the open channel 150 extends generally parallel to a longitudinal axis of the catheter, as shown in FIG. 3A. The open channel 150 may extend partially circumferentially around the inner structure 120 any suitable amount (e.g., number of degrees). For example, in some variations the channel 150 may extend between about 10 degrees and about 350 degrees, between about 30 degrees and about 330 degrees, between about 60 degrees and about 300 degrees, between about 90 degrees and about 270 degrees, between about 120 degrees and about 240 degrees, or between about 150 degrees and about 210 degrees around the inner structure 120. For example, the open channel 150 may extend about 10 degrees, about 30 degrees, about 45 degrees, about 60 degrees, about 75 degrees, about 90 degrees, about 105 degrees, about 120 degrees, about 135 degrees, about 150 degrees, about 165 degrees, about 180 degrees,about 195 degrees, about 210 degrees, about 225 degrees, about 240 degrees, about 255 degrees, about 270 degrees, about 285 degrees, about 300 degrees, about 315 degrees, about 330 degrees, or about 345 degrees around the inner structure 120. One or more conductor wires 112 may traverse the catheter within the channel 150, and configured to free float within the channel 150.

[0056] In some variations, multiple intermediate joining regions 140i may be arranged circumferentially around the inner structure 120 so as to form multiple open, arcuate channels 150 that run longitudinally along the catheter. Each of such multiple channels 150 may, for example, carry a respective set of one or more conductor wires 112 that free float within the channel 150.

[0057] FIG. 4A is a schematic illustration of a portion of an example catheter 400, which may be similar to any of catheters 10, 200, and 300 except as described below. For example, the catheter 400 may include an inner structure 120, an outer structure 130, and a navigation coil 110 wrapped circumferentially around the inner structure 120. The inner structure 120 and the outer structure 130 may be coupled along a distal joining region 140d, at least a portion of which is distal to the navigation coil 110. The inner structure 120 and the outer structure 130 may, in some variations, also be coupled along a proximal joining region near or in the hub 20 (not shown). The inner structure 120 and the outer structure 130 are additionally coupled along an intermediate joining region 140i along a continuous segment of the catheter between the distal joining region 140d and the hub. In some variations, the distal joining region 140d, the intermediate joining region 140i, and / or the proximal joining region may form a continuous joining region along the catheter. Similar to the intermediate joining region 140i in the catheter 300, the intermediate joining region 140i in the catheter 400 may extend only partially circumferentially around the inner structure 120, thereby leaving an uncoupled (e.g., open, not bonded), arcuate segment of the space between the inner and outer structures. For example, in some variations, the cross-sectional angular span of the channel 150 and the cross-sectional angular span of the intermediate joining region 140i may be explementary (i.e., sum to about 360 degrees). The uncoupled regions of the space between the inner and outer structures may form a channel 150 with an arcuate cross-section. The circumferential span of the channel 150 (e.g., number of degrees the channel 150 extends around the inner structure 120) may be any suitable amount, including any of the examples described above with respect to catheter 300.

[0058] However, in the catheter 400 the circumferential location of the channel 150 may change along the length of the catheter 400. For example, as shown in FIGS. 4B-4E depicting cross-sectional views at various axial locations of the catheter 400, the circumferential location of the channel 150 may rotate as the channel 150 traverses the length of the catheter 400, such that the channel 150 is a generally helical lumen. One or more conductor wires 112 may traverse the catheter within the channel 150, and configured to free float within the channel 150.

[0059] FIG. 5A is a schematic illustration of a portion of an example catheter 500, which may be similar to any of catheters 10, 200, 300, and 400 except as described below. For example, the catheter 500 may include an inner structure 120, an outer structure 130, and a navigation coil 110 wrapped circumferentially around the inner structure 120. The inner structure 120 and the outer structure 130 may be coupled along a distal joining region 140d, at least a portion of which is distal to the navigation coil 110. The inner structure 120 and the outer structure 130 may, in some variations, also be coupled along a proximal joining region near or in the hub 20 (not shown).

[0060] The inner structure 120 and the outer structure 130 may be additionally coupled along one or more discrete intermediate joining regions 140i between the distal joining region 140d and the proximal joining region. The intermediate joining region(s) 140i may be located at intermittent longitudinal locations along the catheter between the distal joining region 140d and the hub. For example, in the catheter 500, the intermediate joining region(s) 140i may be longitudinally separated from the distal joining region 140d and / or the proximal joining region. Additionally, the intermediate joining region(s) may be longitudinally separated from each other, and may be equally or unequally longitudinally spaced apart from each other.[00611 Similar to the intermediate joining region 140i in the catheter 300, each intermediate joining region 140i in the catheter 500 may extend only partially circumferentially around the inner structure 120, thereby leaving an uncoupled (e.g., open, not bonded), arcuate segment of the space between the inner and outer structures. For example, in some variations, the cross-sectional angular span of the channel 150 and the cross-sectional angular span of the intermediate joining region 140i may be explementary (i.e., sum to about 360 degrees). The circumferential span of the channel 150 (e.g., numberof degrees the channel 150 extends around the inner structure 120) along any particular intermediate joining region 140i may be any suitable amount, including any of the examples described above with respect to catheter 300.

[0062] Between each intermediate joining region 140i, the channel 150 may include an annular lumen with a ring-shaped cross-section. Accordingly, the cross-sectional shape of the channel 150 may vary along the length of the catheter 500. For example, as shown in FIGS. 5B-5E depicting various cross-sectional views at various longitudinal locations of the catheter 500, the channel 150 may alternate between having an arcuate lumen (FIGS. 5B and 5D corresponding to longitudinal positions coincident with an intermediate joining region 140i) and an annular lumen (FIGS. 5C and 5E corresponding to longitudinal positions not coincident with a joining region). One or more conductor wires 112 may traverse the catheter within the channel 150, and configured to free float within the channel 150.

[0063] FIG. 6A is a schematic illustration of a portion of an example catheter 600, which may be similar to any of catheters 10, 200, 300, 400, and 500 except as described below. For example, the catheter 600 may include an inner structure 120, an outer structure 130, and a navigation coil 110 wrapped circumferentially around the inner structure 120. The inner structure 120 and the outer structure 130 may be coupled along a distal joining region 140d, at least a portion of which is distal to the navigation coil 110. The inner structure 120 and the outer structure 130 may, in some variations, also be coupled along a proximal joining region near or in the hub 20 (not shown).

[0064] Similar to that in the catheter 500, the inner structure 120 and the outer structure 130 may be additionally coupled along one or more discrete intermediate joining regions 140i between the distal joining region 140d and the proximal joining region. The intermediate joining region(s) 140i may be located at intermittent longitudinal locations along the catheter between the distal joining region 140d and the hub. For example, in the catheter 600, the intermediate joining region(s) 140i may be longitudinally separated from the distal joining region 140d and / or the proximal joining region. Additionally, the intermediate joining region(s) may be longitudinally separated from each other, and may be equally or unequally longitudinally spaced apart from each other.

[0065] Similar to the intermediate joining region 140i in the catheter 300, each intermediate joining region 140i in the catheter 600 may extend only partiallycircumferentially around the inner structure 120, thereby leaving an uncoupled (e.g., open, not bonded), arcuate segment of the space between the inner and outer structures. For example, in some variations, the cross-sectional angular span of the channel 150 and the cross-sectional angular span of the intermediate joining region 140i may be explementary (i.e., sum to about 360 degrees). The circumferential span of the channel 150 (e.g., number of degrees the channel 150 extends around the inner structure 120) along any particular intermediate joining region 140i may be any suitable amount, including any of the examples described above with respect to catheter 300.|0066| Between each intermediate joining region 140i, the channel 150 may include an annular lumen with a ring-shaped cross-section. Accordingly, the cross-sectional shape of the channel 150 may vary along the length of the catheter 600. In the catheter 600, the circumferential location of the channel 150 may change along the length of the catheter 600. For example, as shown in FIGS. 6B-6E depicting various cross-sectional views at various longitudinal locations of the catheter 600, the channel 150 may alternate between having an arcuate lumen (FIGS. 6B and 6D corresponding to longitudinal positions coincident with an intermediate joining region 14i) and an annular lumen (FIGS. 6C and 6E corresponding to longitudinal positions not coincident with a joining region). Additionally, the circumferential position of the arcuate lumen may vary along the length of the catheter 600 (e.g., the circumferential position of the channel 150 is rotated in FIG. 6D relative to that shown in FIG. 6B). One or more conductor wires 112 may traverse the catheter within the channel 150, and configured to free float within the channel 150.|0067] Additionally or alternatively, in some variations, the inner structure 120 may include one or more recessed features configured to receive and / or guide the navigation coil 110 and / or conductor wire(s) 112 on the inner structure 120. For example, as shown in FIG. 7, an outer surface of the inner structure 120 may include a recess 122 (e.g., annular recess) sized and shaped to receive the navigation coil 110. The recess 122 may, for example, help retain the longitudinal position of the navigation coil 110 on the inner structure 120 and / or improve coil cohesion during the process of winding the navigation coil 110 on the inner structure 120. In some variations, the surface and / or edges of the recess 122 may be radiused or otherwise contoured to reduce the occurrence of sharp edges against which the navigation coil 110 may abrade, thereby reducing the risk of coil fracture.

[0068] As another example, as shown in FIGS. 7 and 8, an outer surface of the inner structure 120 may include a recess 124 sized and shaped to receive the one or more conductor wires 112. The recess 124 may help further define the channel within which the conductor wire 112 free float. For example, the recess 124 may be helically shaped (FIG. 7) and guide the conductor wire 112 along a helical path in the channel as the conductor wire 112 traverses the length of the catheter. As another example, the recess 124 may be generally longitudinal (FIG. 8) and guide the conductor 112 along a longitudinal path in the channel as the conductor 112 traverses the length of the catheter. In some variations, the surface and / or edges of the recess 124 may be radiused or otherwise contoured to reduce the occurrence of sharp edges against which the conductor wire 112 may abrade, thereby reducing the risk of wire fracture.|0069| In some variations, the inner structure 120 may include multiple channels 150 (e.g., with multiple recesses 124), where each of the channels may be configured to receive at least one respective conductor wire 112 (or conductor wire pair). For example, as shown in FIG. 8, the inner structure 120 may include a plurality of recesses 124 arranged circumferentially around the inner structure 120. Although FIG. 8 depicts an inner structure 120 including four recesses 124 equally distributed around the circumference of the inner structure 120, it should be understood that other variations may include any suitable number of recesses 124 (e.g., two, three, four, five, six or more) that may be equally or unequally distributed around the circumference of the inner structure 120.

[0070] In some variations, the catheter may include multiple navigation coils. At least a portion of the multiple navigation coils may be arranged at different longitudinal locations along the catheter, which may, for example, enable tracking of multiple points along the catheter length or overall shape of the catheter. For example, FIG. 9A is a schematic illustration of a portion of a catheter 900, which may be similar to any of catheters 10, 200, 300, 400, 500, and 600 except as described below. For example, the catheter 600 may include an inner structure 120, and an outer structure 130. The inner structure 120 and the outer structure 130 may be coupled along a distal joining region 140d. The inner structure 120 and the outer structure 130 may, in some variations, also be coupled along a proximal joining region near or in the hub 20 (not shown).

[0071] The catheter 900 may include multiple navigation coils including a first navigation coil 110a and a second navigation coil 110b wrapped circumferentially around the inner structure 120. The first navigation coil 110a and the second navigation coil 110b may be arranged at different longitudinal locations along the inner structure 120. For example, the first navigation coil 110a may be distal to and spaced apart from the second navigation coil 110b. The separation between the first and second navigation coils may, for example, range between 1 mm and about 5 mm, or any suitable distance. In some variations, one or more of the navigation coils may be circumferentially wrapped around the inner structure 120 and received in a recess similar to recess 122 described above with respect to FIG. 7.[0072| Each navigation coil may be conductively coupled to a respective set of conductor wires for carrying signals to and / or from that navigation coil. For example, as shown in FIG. 9A, at least one conductor wire 112a may be joined to the first navigation coil 110a, and at least one conductor wire 112b may be joined to the second navigation coil 110b. The conductor wires 112a, 112b may extend proximally toward the hub (not shown) while free floating within at least one channel 150 defined between the inner structure 120 and the outer structure 130.

[0073] In some variations, the conductor wires 112a and 112b may generally be separated from each other as they extend proximally toward the hub. For example, as shown in FIGS 9A-9C, the channel 150 may include an annular lumen, and the conductor wires 112a and 112b may be arranged at different circumferential positions around the annular lumen. As another example, the catheter may include multiple channels 150 (e.g., as described above with respect to FIG. 8 for example), and each of the conductor wires 112a and 112b may free float within a respective channel 150. In other examples, the conductor wires 112a and 112b (and / or any additional conductor wires may free float within any suitable channel(s) 150, such as a channel with an arcuate lumen, a helical lumen, an annular lumen, or any combination thereof, as described herein with respect to FIGS. 2A-8.

[0074] Although the catheter 900 is shown in FIG. 9A as including two navigation coils, it should be understood that in some variations the catheter may include any suitable number of navigation coils, including one, two, three, four, five, or more navigation coils. Signals for each navigation coil may be carried by a respective set of one or more conductorwires. In some variations, each set of one or more conductor wires may free float within a respective channel between the inner structure 120 and the outer structure 130, while in some variations one or more sets of conductor wires may free float together in a channel.

[0075] In some variations, a catheter in accordance with the present technology may include materials with varying durometer to provide strain relief to the conductor wires 112. Areas of the catheter where the lower durometer material is present may provide strain relief by providing some “give” in response to bending, twisting, and / or other catheter movements, such that these catheter movements load the lower durometer material before loading the conductor wire(s). For example, a transition region where the wire of a navigation coil transitions to a proximally -extending conductor coil may include a material having a lower durometer compared to its surrounding material. As another example, the channel 150 may include a material having a lower durometer compared to its surrounding material. Suitable low durometer materials may include, for example, adhesive (e.g., silicone) or suitable low durometer polymer (e.g., 10A, 20A). The adhesive may be applied to the transition region and / or the channel 150. Additionally or alternatively, at least a portion of the inner structure 120 and / or outer structure 130 may incorporate a low durometer material through suitable manufacturing techniques such as overmolding, 3D printing, and / or the like. As another example, the catheter may additionally or alternatively include an applique or cover slip with adhesive that is applied to the transition region, where the applique or cover slip has a low durometer material. In some variations, the strain relief material (e.g., low polymer tubing) may be arranged in the transition region but not bonded to the navigation coil and / or the conductor wire, such that the portion of the conductor wire in the transition region free floats within the strain relief material itself.

[0076] Additionally or alternatively, one or more lubricants may be applied to the conductor wires 112 and / or the channel 150 to reduce friction between the conductor wires 112 and its surroundings, thereby further reducing risk of mechanical wire failure. For example, the conductor wires 112 and / or the channel 150 may be coated with silicone oil, grease, or a suitable lubricant powder (e.g., graphite, talc, etc.). In some variations, for example, a twisted wire pair of conductor wires 112 may be drawn through a die that enables application of a powder to coat the twisted wire pair with lubricant powder. Additionally or alternatively, a lubricious material may be incorporated into the inner structure 120 and / or the outer structure 130 such that the channel 150 has walls including such lubriciousmaterial. Examples of lubricious material include a PTFE coating or lining, and / or suitable lubricious polymer additives in the material of the inner structure 120 and / or the outer structure 130 (e.g., Mobilize additive for thermoplastics, available from Compounding Solutions LLC (Lewiston, ME, USA)).II. Catheter Manufacturing Methods

[0077] FIGS. 10-13 depict flowcharts summarizing example variations of methods for manufacturing a catheter with a circumferentially wound navigation coil and one or more channels for free floating conductor wires in accordance with the present technology. These methods may be applicable, for example, for manufacturing any of the example catheters described herein, including those described above with respect to FIGS. 2A-9C.

[0078] FIG. 10 summarizes an example method 1000 for manufacturing a catheter in accordance with the present technology. The method 1000 includes forming an inner structure 1010, forming an EM navigation coil around the inner structure 1020, arranging conductor wires along the inner structure 1030, arranging the inner structure within the outer structure 1040, and coupling the inner structure and the outer structure 1050. In some variations, coupling the inner structure and the outer structure at least in part defines at least one channel configured to receive the conductor wires, where the conductor wires are free floating within the channel(s). Once the inner structure and outer structure are coupled, a proximal end of the inner structure and / or outer structure may furthermore be coupled to a hub configured for external use and control of the catheter.

[0079] Forming the inner structure 1010 functions to form an elongated member around which the navigation coil may be arranged. For example, the inner structure may include an extruded tubular member including one or more of a liner material (e.g., PTFE liner), a braid, and / or other suitable polymer. The inner structure may, in some variations, also include a lumen for carrying a device (e.g., treatment device) and / or one or more lumens such as for pull wires, irrigation fluid, and / or the like. In some variations, as further described herein, the inner structure may include one or more recesses for receiving the navigation coil (e.g., an annular recess) and / or receiving at least one conductor wire (e.g., a longitudinal recess). The inner structure may be extruded, injection molded, 3D printed, and / or otherwise formed in any suitable manner.[0080 After forming the inner structure, the EM navigation coil and the conductor wire(s) may be arranged on the inner structure. For example, forming the EM navigation coil around the inner structure 1020 may include wrapping a conductive wire (e.g., copper) around the inner structure to form at least a portion of the navigation coil. Additionally or alternatively, at least a portion of the navigation coil may be wrapped into a coil shape separately from the inner structure, then positioned over or around the inner structure. Furthermore, in arranging conductor wires along the inner structure, one or more conductor wires may also be arranged along the inner structure in one or more anticipated pathways for a channel to be defined between adjacent surfaces of the inner structure and the outer structure. In some variations a conductor wire may include a trailing end of the navigation coil that is integrally formed with the navigation coil, or may be a separate wire that is conductively coupled (e.g., bonded) to the navigation coil in order to carry electrical signals to and / or from the navigation coil. Furthermore, in some variations one or more additional strain relief materials (e.g., adhesive, low durometer polymer, etc.) may be arranged over and / or around the navigation coil and / or the conductive wires to provide additional strain relief.

[0081] The assembly of the inner structure, the navigation coil, and the conductor wires may subsequently be combined with an outer structure (e.g., telescopically engaged with or circumferentially surrounded by the outer structure). For example, the outer structure may include a tubular member including one or more of a braid, a jacket material, heat shrink and / or the like. In some variations, arranging the inner structure 1040 (with the navigation coil and conductor wires arranged thereon) within the outer structure includes pulling the inner structure through the outer structure or pulling the outer structure over the inner structure.[0082| After the inner structure and outer structures are arranged relative to one another in a desired configuration, the method may further include coupling the inner structure and the outer structure 1050. The inner structure and the outer structure may be coupled together at one or more joining regions (e.g., distal joining region, intermediate joining region, proximal joining region). In some variations, the location and / or pattern of the joining regions where the inner structure and outer structure are coupled may at least in part define the size and / or shape of the channel(s) within which the conductor wires free float. For example, wall surfaces of the inner structure and the other structure may becoupled together to define a channel that includes an annular lumen, an arcuate lumen, and / or a helical lumen, as described in further detail herein. The coupling of the inner structure and the outer structure may be performed in any suitable manner, such as laser welding, reflow processes, or by applying adhesive (e.g., potting with adhesive). As another example, the navigation coil may be activated to function as a resistance heater to bond the inner structure and outer structure together.

[0083] FIG. 11 summarizes an example method 1100 for manufacturing a catheter in accordance with the present technology. The method 1100 includes forming an inner structure 1110, forming an EM navigation coil around the inner structure 1120, arranging sacrificial wires along the inner structure 1130, arranging the inner structure within the outer structure 1140, coupling the inner structure and the outer structure 1150, and replacing the sacrificial wires with conductor wires 1160. The method 1100 may be similar to the method 1000 described above with respect to FIG. 10, except as described herein. For example, forming an inner structure 1110, forming an EM navigation coil around the inner structure 1120, arranging the inner structure within the outer structure 1140, and coupling the inner structure and the outer structure 1150 may be similar to their respective counterparts (1010, 1020, 1040, and 1050) of method 1000.

[0084] However, in method 1100, instead of initially forming the conductor wires around the inner structure prior to coupling the inner structure and the outer structure together, sacrificial wires are instead arranged around the inner structure to function as placeholders for the functional conductor wires. The sacrificial wires may not necessarily include an electrically conductive material, for example. However, the sacrificial wires may have equal or greater diameter than the eventual conductor wires, so as to occupy space around which one or more channels (e.g., channel 150) may be formed. After the inner and the outer structures are coupled together, the method may include replacing the sacrificial wires with conductor wires 1160, which may involve pulling the sacrificial wires out of the channel(s) and inserting new, functional conductor wires into the channel(s). In some variations, the sacrificial wires may be coated with a lubricant (e.g., silicone oil, graphite powder, talc powder, etc.) and / or include a lubricious material such as a PTFE coating.

[0085] In some variations, instead of coupling together separately-formed inner and outer structures, the outer structure may be formed over the inner structure. For example,FIG. 12 summarizes an example method 1200 for manufacturing a catheter in accordance with the present technology. Method 1200 includes forming an inner structure 1210, forming an EM navigation coil around the inner structure 1220, arranging conductor wires along the inner structure 1230, and forming an outer structure around the inner structure 1250. In some variations, forming the outer structure around the inner structure at least in part defines at least one channel configured to receive the conductor wires, where the conductor wires are free floating within the channel(s). Once the outer structure is formed over the inner structure, a proximal end of the inner structure and / or outer structure may furthermore be coupled to a hub configured for external use and control of the catheter. The method 1200 may be similar to the method 1000 described above with respect to FIG. 10, except as described herein. For example, forming an inner structure 1210, forming an EM navigation coil around the inner structure 1220, and arranging the inner structure within the outer structure 1230 may be similar to their respective counterparts (1010, 1020, 1040, and 1050) of method 1000.[0086 However, instead of coupling together the inner structure and the outer structure, the method 1200 includes forming the outer structure around the inner structure 1250 using any suitable technique such as a reflow process, overmolding process, and / or 3D printing process, etc. In some variations, the method 1200 may further include applying a mask around the inner structure 1240 prior to forming the outer structure around the inner structure. The mask may function to prevent adhesion (e.g., polymer adhesion) between certain portions of the inner structure and the outer structure, such as regions adjacent to and / or corresponding to the anticipated channel(s) to be formed between the inner and outer structures. The mask may, for example, include polyimide tape that is lightly bonded to the inner structure and is present during the formation of the outer structure. As another example the mask may include a polymer cover slip that is arranged over the inner structure during the formation of the outer structure, and may be later removed or left in place.

[0087] As another example in which the outer structure is formed over the inner structure, FIG. 13 summarizes an example method 1300 for manufacturing a catheter in accordance with the present technology. Method 1300 includes forming an inner structure 1310, forming an EM navigation coil around the inner structure 1320, arranging sacrificial wires along the inner structure 1330, forming an outer structure around the inner structure 1350, and replacing the sacrificial wires with conductor wires 1360. The method 1300 maybe similar to the method 1100 described above with respect to FIG. 11, except as described herein. For example, forming an inner structure 1310, forming an EM navigation coil around the inner structure 1320, arranging sacrificial wires along the inner structure 1330, and replacing the sacrificial wires with conductor wires 1360 may be similar to their respective counterparts (1110, 1120, 1130, and 1160) of method 1000.[0088 However, instead of coupling together the inner structure and the outer structure, the method 1300 includes forming the outer structure around the inner structure 1350 using any suitable technique such as a reflow process, overmolding process, and / or 3D printing process, etc. Like the method 1200, in some variations the method 1300 may further include applying a mask around the inner structure 1340 prior to forming the outer structure around the inner structure. The mask may function to prevent adhesion (e.g., polymer adhesion) between certain portions of the inner structure and the outer structure, such as regions adjacent to and / or corresponding to the anticipated channel(s) to be formed between the inner and outer structures.Conclusion

[0089] Although many of the variations are described above with respect to systems, devices, and methods in relation to a catheter with EM navigation sensors, the technology is applicable to other applications and / or other approaches. Moreover, other variations in addition to those described herein are within the scope of the technology. Additionally, several other variations of the technology can have different configurations, components, or procedures than those described herein. A person of ordinary skill in the art, therefore, will accordingly understand that the technology can have other variations with additional elements, or the technology can have other variations without several of the features shown and described above with reference to FIGS. 1-12.

[0090] The descriptions of variations of the technology are not intended to be exhaustive or to limit the technology to the precise form disclosed above. Where the context permits, singular or plural terms may also include the plural or singular term, respectively. Although specific variations of, and examples for, the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology, as those skilled in the relevant art will recognize. For example, while steps arepresented in a given order, alternative variations may perform steps in a different order. The various variations described herein may also be combined to provide further variations.

[0091] As used herein, the terms “generally,” “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values that would be recognized by those of ordinary skill in the art.[0092 Moreover, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in reference to a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of the items in the list. Additionally, the term "comprising" is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and / or additional types of other features are not precluded. It will also be appreciated that specific variations have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. Further, while advantages associated with certain variations of the technology have been described in the context of those variations, other variations may also exhibit such advantages, and not all variations need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other variations not expressly shown or described herein.

Claims

CLAIMSI / Wc claim:

1. A medical device comprising: an elongated member comprising an inner structure, an outer structure arranged circumferentially around the inner structure, and a channel defined by an outer surface of the inner structure and an inner surface of the outer structure; an electromagnetic navigation coil wrapped circumferentially around the inner structure and arranged between the inner structure and the outer structure; and at least one conductor wire extending from the navigation coil and free floating within the channel along the elongated member.

2. The device of claim 1, wherein a distal portion of the inner structure and a distal portion of the outer structure are coupled along a distal joining region.

3. The device of claim 1 or 2, wherein an intermediate portion of the inner structure and the intermediate portion of the outer structure are coupled along at least one or more intermediate joining regions.

4. The device of any one of claims 1-3, wherein an entire length of the inner structure and an entire length of the outer structure are continuously coupled along a continuous joining region.

5. The device of any one of claims 1-4, wherein the outer structure comprises an outer tubular member and the inner structure comprises an inner tubular member arranged coaxially within the outer tubular member.

6. The device of any one of claims 1-5, wherein at least a portion of the channel comprises an annular lumen.

7. The device of any one of claims 1-5, wherein at least a portion of the channel comprises an arcuate lumen.

8. The device of any one of claims 1-5, wherein at least a portion of the channel comprises a helical lumen.

9. The device of any one of claims 1-8, wherein an outer surface of the inner structure comprises an annular recess and the navigation coil is in the annular recess.

10. The device of any one of claims 1-9, wherein an outer surface of the inner structure comprises a recess forming a wall of the channel.

11. The device of any one of claims 1-10, further comprising a flexible strain relief material arranged over a portion of the navigation coil and a portion of the at least one conductor wire.

12. The device of any one of claims 1-11, wherein the medical device comprises a plurality of navigation coils.

13. The device of claim 12, wherein the elongated member comprises a plurality of channels defined by the outer surface of the inner structure and the inner surface of the outer structure.

14. The device of claim 13, further comprising a plurality of conductor wires, wherein each conductor wire is coupled to a respective navigation coil and extending along the elongated member with free movement within a respective channel.

15. The device of any one of claims 1-14, wherein the medical device is a catheter.

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