Method for electromagnetically tracking catheter position and articulation using two 5 degrees-of-freedom sensors

Abstract

A catheter including a polytetrafluoroethylene (PIPE) tube defining a lumen of the catheter, a reflow layer disposed over the inner PTFE tube, a braid layer the disposed on the inner reflow layer, a sensor subassembly disposed on the braid layer, the sensor subassembly including a PTFE tube, a pair of coil carriers, and a pair of electromagnetic (EM) sensors, and an outer jacket layer disposed on the sensor subassembly.

Description

Patent ApplicationAttorney Reference No. A0012265W001 (00017-01269PCT00)METHOD FOR ELECTROMAGNETICALLY TRACKING CATHETER POSITION AND ARTICULATION USING TWO 5 DEGREES-OF-FREEDOM SENSORSBACKGROUND1. Technical Field

[0001] The disclosure relates to elongated catheters and, more specifically, to methods of manufacturing elongated catheters including sensors for three-dimensional location of the catheter.2. Discussion of Related Art

[0002] A common interventional procedure in the field of pulmonary medicine is bronchoscopy (both manual or robotic), in which a catheter is inserted into the airways through the patient’s nose or mouth. This insertion may be manual, robotic, or motor assisted. The structure of a catheter generally includes a long, thin, flexible tube that typically contains one or more of three elements: an illumination assembly for illuminating the region distal to the catheter’s tip via an optical fiber connected to an external light source; an imaging assembly for delivering back a video image from the bronchoscope's distal tip; and a lumen or working channel through which instruments may be inserted, including but not limited to placement (e.g., guide wires), diagnostic (e.g., biopsy tools) and therapeutic (e.g., treatment catheters or laser, cryogenic, radio frequency, or microwave tissue treatment probes) instruments and others.

[0003] In some instances, a locatable guide may be positioned at a distal end of the lumen of the catheter, the locatable guide including a six-degree of freedom (6 DOF) sensor which provides an indication of location in space (X, Y, Z coordinates) and an indication of orientation (pitch, yaw, and roll). When the distal end of the catheter is positioned adjacent to the targeted tissue, the locatable guide may be removed. The catheter may optionally include a second sensor, e.g., a five-degree of freedom (5 DOF) sensor. With the locatable guide removed, an instrument may be inserted through the catheter in order to act on the targeted tissue (e.g., perform a biopsy or ablation of the targeted tissue). However, when the locatable guide is removed, the orientation of the roll of the catheter is no longer known. Accordingly, improvements to current catheter and sensor systems are desired.Patent ApplicationAttorney Reference No. A0012265W001 (00017-01269PCT00)SUMMARY

[0004] One general aspect includes a catheter subassembly including a polytetrafluoroethylene (PTFE) tube; a pair of coil carriers disposed on the PTFE tube. The catheter also includes a pair of electromagnetic (EM) sensors, each EM sensor secured to one of the pair of coil carriers.

[0005] Implementations may include one or more of the following features. The catheter subassembly where each coil carrier includes a sensor slot configured to receive one EM sensor of the pair EM sensors. The catheter subassembly may include a pair of PTFE tubes configured to receive a twisted pair of wires extending from each EM sensor. One coil carrier of the pair of coil carriers includes a wire slot configured to receive a twisted pair of wires extending from one EM sensor of the pair of EM sensors. The PTFE tube is configured for advancement over a metallic braid. The pair of EM sensors are micro coil sensors. A first of the pair of micro coils sensors is oriented 180 degrees form the orientation of a second of the pair of micro coil sensors. A first of the pair of EM sensors is micro coil sensor and a second of the pair of EM sensors is an air coil.

[0006] A further general aspect is directed to a catheter system including a catheter; a first 5- degree of freedom (5 DOF) micro coil sensor formed on a distal end of the catheter and configured to detect an electromagnetic field and generate a first signal, a second 5 DOF sensor formed on the catheter proximally of the first 5 DOF micro coil sensor configured to detect the electromagnetic field and generate a second signal, and an application stored in a memory including instructions that when executed a processor receive the first signals and the second signals and determine a location and orientation of the catheter in 6-degrees of freedom. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

[0007] Implementations may include one or more of the following features. The catheter system where the second 5 DOF sensor is an air coil sensor. The second 5 DOF sensor is a micro coil sensor. The application detects an articulation of the catheter based on the first and second signals. The application generates a representation of the catheter and displays the representation on one or more of intraprocedural images, preprocedural images, or models generated from the intraprocedural images or the preprocedural images. The catheter system may include at least one coil carrier. The catheter includes a polytetrafluoroethylene (PTFE) tube defining a lumen ofPatent ApplicationAttorney Reference No. A0012265W001 (00017-01269PCT00) the catheter and configured to receive a twisted pair of wires extending from the first 5 DOF micro coil sensor or the second 5 DOF sensor. Implementations of the described techniques may include hardware, a method or process, or computer software on a computer-accessible medium.

[0008] Another general aspect is directed to a catheter including a polytetrafluoroethylene (PTFE) tube defining a lumen of the catheter; a reflow layer disposed over the inner PTFE tube, a braid layer the disposed on the inner reflow layer. The catheter also includes a sensor subassembly disposed on the braid layer, the sensor subassembly including a PTFE tube, a pair of coil carriers, and a pair of electromagnetic (EM) sensors; and an outer jacket layer disposed on the sensor subassembly. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

[0009] Implementations may include one or more of the following features. The catheter where the EM sensors are micro coil sensors. Each of the pair of coil carriers include a slot for receiving one of the pair of EM sensors. The sensor subassembly further may include a pair of PTFE tubes configured to receive a twisted pair of wires extending from each of the pair of sensors. The outer jacket secures the sensor subassembly to the braid layer.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Various aspects and embodiments of the disclosure are described hereinbelow with references to the drawings, wherein:

[0011] FIG. l is a top view of an air coil sensor in accordance with the disclosure;

[0012] FIG. 2 is an exploded view diagram of a catheter in accordance with the disclosure;

[0013] FIG. 3 is a perspective view of a micro coil sensor in accordance with the disclosure;

[0014] FIG. 4 is a cross-sectional view of a catheter in accordance with the disclosure;

[0015] FIG. 5 is a cross-sectional view of a catheter in accordance with the disclosure;

[0016] FIG. 6 is a perspective view of a subassembly of the catheter of FIG. 5 in accordance with the disclosure;

[0017] FIG. 7 is a top view of the subassembly of FIG. 6;

[0018] FIG. 8 is a bottom view of the subassembly of FIG. 6; and

[0019] FIG. 9 is a schematic view of a system for detection of a catheter in accordance with the disclosure.Patent ApplicationAttorney Reference No. A0012265W001 (00017-01269PCT00)DETAILED DESCRIPTION

[0020] This disclosure is directed to a catheter and assembly system with the ability to resolve position and orientation of a distal portion of the catheter in 6 DOF during a procedure. A further aspect of the disclosure is directed to easing construction and assembly of catheters for endoluminal navigation. These and other aspects of the disclosure are described in greater detail below.

[0021] FIG. 1 depicts an air coil electromagnetic (EM) sensor 100 in accordance with aspects of the disclosure. The air coil EM sensor 100 is formed of a wire 102 wound around a support structure (e.g., a mandrel or catheter layer). The EM sensor 100 may include two or more layers of windings of the wire 102. In practice, the wire 102 is wound around the support structure in two different directions (e.g., clockwise and counterclockwise) until sufficient windings are formed. The wire is the brought together and twisted together to form a twisted pair 104. The formation of the twisted pair 104 extends along the length of a catheter where it connects to circuitry of a catheter navigation system. When the air coil EM sensor 100 is placed within an EM field, a current is induced in the air coil EM sensor 100. This current is transmitted via the twisted pair to a navigation system associated and a determination of the location of the air coil EM sensor 100 in the EM field can be made. The twisted pair 104 achieves destructive interference, cancelling all or substantially all of the interference which results from the current flowing through the strands of the twisted pair 104.

[0022] FIG. 2 depicts an exploded view of a catheter 200 in accordance with the disclosure. A multi-part catheter 200 as depicted in FIG. 2 is assembled on a mandrel (not shown). The assembly of the catheter 200 starts with advancing a polytetrafluoroethylene (PTFE) tube 202 over the mandrel. As the inner most layer of the catheter 200, the PTFE tube 202 defines the diameter of the inner lumen of the catheter 200. Next, a reflow layer formed of a polyamide and polyether thermoplastic elastomer (e.g., PEBAX®) tube 204 is advanced over the PTFE tube 200. A braid layer 206 is advanced over reflow layer 204. An air coil sensor 100 is formed on the braid layer. Finally, an outer jacket layer 208, formed of a thermoplastic is advanced over the braid layer 206 and the air coil sensor 100

[0023] At various times during the assembly process, a reflow process may be undertaken where the thermoplastic of the reflow layer 204 and outer jacket 208 are heated above their melting point and allowed to reflow into adjacent layers of the catheter 200. PTFE tube 202 has a higherPatent ApplicationAttorney Reference No. A0012265W001 (00017-01269PCT00) melting point than the thermoplastic of the reflow layer 204 and the outer jacket 208, and thus the reflow processes selectively melt the reflow layer or the outer jacket into the braid layer 206 of the catheter 200.

[0024] Through the use of two air coil EM sensors 100 on a single catheter 200, when the catheter 200 is articulated, the relative positions of the two air coil EM sensors 100 in an EM field can be detected. By detecting the location of the two air coil sensors 100, the amount of articulation of the catheter 200 can be detected. In accordance with aspects of the disclosure, the articulation can be depicted in a 3D model used for navigation of the patient’s lumen (e.g., the airways of the lungs). Determining the articulation is useful to the clinician during navigation of the lungs where at each bifurcation of the airways the catheter 200 must be articulated in order to align the distal tip of the catheter 200 with the desired airway before the catheter 200 can be advanced further into the airways.

[0025] The detected amount of articulation (e g., change in relative position of the air coil EM sensor 100 formed on or near a distal end of the catheter 200 compared to the position of the air coil EM sensor 100 formed proximal of the distal end of the catheter can be compared to an amount of force applied by the motors connected to the catheter 200 via the pull wires or tendons (not shown in FIG. 2) or an amount of pull wire or tendon retrieved or released. These comparisons along with others can be employed to provide feedback to the clinician regarding the force required to achieve the articulation, resistances from the body tissues to the articulation, or a rate of articulation (motor drive speed) to achieve the articulation.

[0026] While certainly beneficial to be able to detect the articulation of catheter 200 and to display a representation of the articulation in either intraprocedural images, pre-procedural images, or models derived from images (e.g., a three-dimensional (3D) model) derived from the images, the catheter 200 with two 5 DOF air coil EM sensors 100 of FIG. 1 may not easily enable the determination of location and orientation of the distal portion of the catheter in 6 DOF. At least in part the difficulty in determining location and orientation may be due to a difficulty tracking the location of the pull wire directions as the catheter rolls.

[0027] FIG. 3 depicts a micro coil sensor 302 in accordance with the disclosure. A micro coil sensor 302 is constructed similarly to an air coil EM sensor 100, except that rather than having a wire 102 wrapped around a portion of the catheter 200, a fine gauge wire (e.g., even finer than employed for the air coil EM sensor 100) is wrapped around a solid ferro-magnetic central corePatent ApplicationAttorney Reference No. A0012265W001 (00017-01269PCT00)304. The solid ferro-magnetic core 304 increases signal gain for the detected EM field. A twisted pair 306 extends from the ferro-magnetic core to be connected to various systems as described above in connection with the air coil EM sensor 100.

[0028] FIG. 4 depicts a distal portion of a catheter 400 in accordance with the disclosure in which the location and orientation of the distal portion of the catheter 400 can be determined in 6 DOF using two 5 DOF sensors. The catheter 400 has substantially the same construction as the catheter depicted in FIG. 2, except that an air coil EM sensor 100 is not formed on the distal end of the catheter 200. Rather, a 5 DOF micro coil sensor 302 is positioned at the distal end of the catheter 400. A twisted pair 306 of the wires wrapped around the ferro-magnetic central core extend proximally from the micro coil sensor 302. The twisted pair of wires may be formed of, for example, between 46- and 50-gauge wire. In addition, as described below the micro coil sensor 302 may be mounted to the catheter 400 on top of the metallic braid 220.

[0029] Both the air coil EM sensor 100 and the micro coil sensor 302 detect the location (X, Y, Z) coordinates and the orientation (pitch and yaw) 5 DOF, at the center of the respective sensor. The air coil EM sensor 100 is positioned a known distance proximally of the micro coil sensor 302 and is formed symmetrically around the lumen 402 of the catheter 400. The location and orientation (5 DOF) of the air coil EM sensor 100 is detected at point 404, which substantially aligns with a centerline 406 of the lumen 402 of the catheter 400. The micro coil sensor 302 is off set to one side of the catheter 400. The location and orientation (5 DOF) of the micro coil sensor 302 is detected at point 408. With reference to FIGS. 2 and 4, the micro coil sensor 302 may be, for example, secured in the catheter 400 between the second PTFE tube 214 and the metallic braid 220.

[0030] As depicted in FIG. 4, based on the relative geometry of point 408 of the micro coil sensor 302 and point 404 of the air coil EM sensor 100 known when in a straight un-articulated position, a true center 410 can be determined. True center 410 is the point of intersection of the centerline 406 of the lumen 402 and a line from point 408 perpendicular to the centerline. A triangle is thus defined by the distance “d” from point 404 to point 408, a distance “1” from point 404 to point 410 and a distance “h” from point 408 to point 410. When in the unarticulated position and the catheter is rotated or rolls, the detected location of the micro sensor 302 (i.e. point 408) changes, however, the detected position of the air coil EM sensor 100 (i.e., point 404) does not. Thus, by tracking the triangle, a determination of the catheter roll can be determinedPatent Application Attorney Reference No. A0012265W001 (00017-01269PCT00) using a mathematical transformation (e.g., Procrustes transformation). In this manner, a 6 DOF location and orientation of a catheter 400 can be determined using two 5 DOF sensors.

[0031] As noted above with respect to catheter 200, catheter 400 may also include pull wires or tendons (not shown) and is capable of being articulated. Specifically, in accordance with an aspect, the section of the catheter 400 between the air coil EM sensor 100 and micro coil sensor 302 can be articulated. Because the air coil EM sensor’s 100 position correlates to the centerline of the catheter lumen 402 while the micro-coil sensor 302 is offset from the centerline 406, the mathematical transformation (e.g., Procrustes transformation) can be used to assess changes in the 5 DOF outputs from each respective sensor (e.g., changes in linear and rotational values). Together with the known geometry of the locations of the sensor in the catheter 400, the articulation of the catheter 400 can be calculated. As with the catheter 200, this output may be employed in connection with a display where a representation of the catheter and its articulation in 6 DOF is presented on intraprocedural images, preprocedural images, or models (e.g., 3D models formed from the images).

[0032] While aspects of the disclosure in connection with catheter 400 have employed an air coil EM sensor 100, the disclosure is not so limited. FIG. 5 depicts a further aspect of the disclosure incorporating two micro coil sensors 302 in catheter 500. Each micro coil sensor 302 is secured to the catheter 500 via coil carriers 502. The catheter 500 of FIG. 5 is formed by placing an inner PTFE layer 504 defining a central lumen 505 over a mandrel (not shown). A reflow layer 506 is placed over the inner PTFE layer 504. A metallic braid 508 is placed over the reflow layer 506. The coil carriers 502 are secured to a second PTFE layer 510. The micro coil sensors 302 are secured to slots (described in greater detail below) formed in the coil carriers 502. As shown in FIG. 5, the micro coil sensors 302 are placed 180 degrees from one another or on opposite sides of the catheter 500. Twisted pairs 512 of the wire forming the micro-coil sensors 302 are placed within PTFE tubes (not shown) that are secured to the second PTFE layer 510. The PTFE tubes protect the twisted pair 512 from stresses associated with manufacturing process and during a navigation procedure. In accordance with an aspect of the disclosure, when the second PTFE layer 510, coil carriers 502, and micro coil sensors 302 are assembled together as a subassembly, the subassembly is advanced over the metallic braid 508 and a reflow heating process is undertaken. The heating causes the reflow material 506 to soften and flow into the metallic braid 508 integrating the two. The reflow material 506 also adheres or secures the innerPatent Application Attorney Reference No. A0012265W001 (00017-01269PCT00)PTFE layer. An outer jacket layer 514 is advanced over the second PTFE layer 510, coil carriers 502, and micro coil sensors 302. A second reflow process causes the outer jacket layer 514 to shrink over the second PTFE layer 510 and consolidate the entire assembly into the catheter 500.

[0033] Alternatively, in accordance with a further aspect of the disclosure, when employed in an articulating catheter, the construction of the catheter 500 may be substantially the same as catheter 200 (see FIG. 2), except that micro coil carriers 502 may be used instead of two air coil sensors 100. In addition, and as detailed above, the coil carriers 502 may be secured to a PFTE layer placed over the metallic braid 220. Still further, and without departing from the scope of the disclosure, an air coil EM sensor 100 may be formed on the second PTFE layer 510 or the coil carrier 502 instead of the proximal micro coil sensor 302.

[0034] FIG. 6 is a perspective view of a sensor subassembly 550 for use in the catheter 500 of FIG. 5, in accordance with an aspect of the disclosure. A first coil carrier 502 is located at the distal end of the second PTFE layer 510 and a first slot 552 is formed in the top of the coil carrier 502. In accordance with some aspects, the first slot 552 may not completely bisect the coil carrier 502 but may terminate prior to reaching the distal end of the subassembly 550. The first slot 552 is sized to receive the micro coil sensor 302 with an interference fit to secure the micro coil sensor 302. The second coil carrier 502 is depicted in FIG. 6 with a second slot 554 aligned with the first slot 552 of the first coil carrier 502 in the longitudinal direction. In some aspects, the second slot 554 may be narrower than the first slot 552, and the second slot 554 is configured to receive the twisted pair 512 of the micro coil sensor 302 secured in the first slot 552 of the first coil carrier 502 located at the distal end of the subassembly 550. Though not shown in FIG. 6, in some further aspects, the second coil carrier 502 may also include a first slot 552, on the opposite side of second coil carrier 502 of the second slot 554 and configured to receive a second micro coil sensor 302.

[0035] FIG. 7 depicts a top view of the subassembly 550 showing a micro coil sensor twist pair 512 extending between the first or distal coil carrier 502 and the proximal or second coil carrier 502. The arrangement of the coil carriers 502 is consistent with the description of the coil carriers 502 in FIGS. 5 and 6. FIG. 8 depicts a bottom view of the subassembly 550. In accordance with an aspect of the present disclosure, the first or distal coil carrier 502 may not include a second slot 554. As shown, in some aspects, the second or proximal coil carrier 502 may include a first slot 552 for receiving a micro coil sensor 302.Patent ApplicationAttorney Reference No. A0012265W001 (00017-01269PCT00)

[0036] In some aspects, by placing the micro coil sensors 302 180 degrees apart around the catheter 500 using the subassembly 550, the roll detection method described above in connection with the air coil EM sensor 100 and the micro coil sensor 302 can also be undertaken. The center points of the micro coil sensors 302 may be separated from one another in a transverse direction, relative to the longitudinal axis of the catheter 500. As described above, using geometric relationships, a centerline of the catheter 500 can be calculated, and as the catheter 500 is rotated or articulated, the changes in position of the distal micro coil sensor 302 relative to the changes of the proximal micro coil sensor 302 can resolve the position of the distal end of the catheter in 6 DOF based on the output from the two 5 DOF sensors. In addition, a representation of the catheter’s articulation can be generated and presented in one or more user interfaces associated with intraluminal navigation software. For example, the representation of the catheter and its articulation may be depicted in intraprocedural images, preprocedural images, and 3D models derived from the images.

[0037] Still further, though described in connection with air coil EM sensors or micro coil sensors 302, the disclosure is not so limited and alternative sensors may be employed without departing from the scope of the disclosure including tunnel magnetoresistance (TMR) sensors as well as other forms of EM sensors can be employed without departing from the scope of the disclosure. As an example, a TMR sensor assembly may include a triplet of TMR sensors arranged on a flexible circuit and secured to the braid layer 206 (or another layer of the catheter 200) via an adhesive. The flexible circuit wraps around the catheter and may be arranged substantially 180 degrees around the catheter 200 from a second sensor (e.g., micro coil sensor 302 on the distal tip of the catheter). The use of a triplet of TMR sensors enables resolution of the position and orientation of the TMR sensor assembly in 6 DOF. The TMR sensor assembly may replace either the air coil EM sensor 100 or the micro coil sensor 302, or both without departing from the scope of the disclosure. Alternatively, a single TMR sensor may utilized on the flexible circuit to detect position and orientation of the catheter in 5 DOF. Mathematically the offset location of the TMR sensor (or sensor assembly) from the micro coil 302 or the air coil EM sensor 100 enables the roll and articulation calculations described elsewhere herein.

[0038] Still further, though described herein with the two micro coil sensors being substantially parallel, the disclosure is not so limited and at least one of the micro coil sensors 302 of FIG. 5 may be arranged orthogonally to the other micro coil sensor 302.Patent Application Attorney Reference No. A0012265W001 (00017-01269PCT00)

[0039] Yet a further aspect of the disclosure is directed to aspects of the EM field generation. As will be appreciated, an EM field generator may utilize a variety of signals and signal patterns to generate the EM field. Some forms of EM field can result in noise in the induced signals in the EM sensor. Accordingly, the EM field generator may generate EM fields using multiple different input signals and signal patterns. Different portions of these input signals and signal patterns are tuned for the EM sensors being employed in the catheter 200. For example, one portion of the input signal may be tailored to limit noise in the EM field detected by a TMR sensor, while a second portion of the input signal may be tailored to enhance detection by a micro-coil sensor. These differences in input signal and therewith the EM field generated may be differences in frequency, duration, phase shift, magnitude and others without departing from the scope of the disclosure. Accordingly, the EM field generated may be tuned for the EM sensors employed on the catheter to generate an EM field that enables clear detection of the location of the EM sensors within the EM field and limits noise and other factors making position and orientation detection more challenging.

[0040] Reference is now made to FIG. 9, which is a schematic diagram of a system 600 configured for use conducting intraluminal navigation. System 600 may include a workstation 601, and optionally an imaging device 615 (e.g., a fluoroscope, CT imaging device, or an ultrasound imaging device). In some embodiments, workstation 601 may be coupled with imaging device 615, directly or indirectly (e.g., by wireless communication). Workstation 601 may include a memory 602, a processor 604, a display 606 and an input device 610. Processor 604 may include one or more hardware processors. Workstation 601 may optionally include an output module 612 and a network interface 608. Memory 602 may store an application 618 and image data 614. Application 618 may include instructions executable by processor 604 for executing the methods of the disclosure.

[0041] Application 618 may further include a user interface 616. Image data 614 may include the preprocedural CT images, intraprocedural images, 3D models, fluoroscopic images, fluoroscopic 3D reconstructions or more slices of the 3D reconstruction. Processor 604 may be coupled with memory 602, display 606, input device 610, output module 612, network interface 608 and imaging device 615. Workstation 601 may be a stationary computing device, such as a personal computer, or a portable computing device such as a tablet computer. Workstation 601 may embed a plurality of computer devices.Patent Application Attorney Reference No. A0012265W001 (00017-01269PCT00)

[0042] Memory 602 may include any non-transitory computer-readable storage media for storing data and / or software including instructions that are executable by processor 604 and which control the operation of workstation 601 and, in some embodiments, may also control the operation of imaging device 615. In an embodiment, memory 602 may include one or more storage devices such as solid-state storage devices, e.g., flash memory chips. Alternatively, or in addition to the one or more solid-state storage devices, memory 602 may include one or more mass storage devices connected to the processor 604 through a mass storage controller (not shown) and a communications bus (not shown).

[0043] Although the description of computer-readable media contained herein refers to solid- state storage, it should be appreciated by those skilled in the art that computer-readable storage media can be any available media that can be accessed by the processor 604. That is, computer readable storage media may include non-transitory, volatile, and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. For example, computer-readable storage media may include RAM, ROM, EPROM, EEPROM, flash memory or other solid-state memory technology, CD-ROM, DVD, Blu-Ray or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which may be used to store the desired information, and which may be accessed by workstation 601.

[0044] Application 618 may, when executed by processor 604, cause display 606 to present user interface 616. User interface 616 may be configured to present to the user a three-dimensional (3D) view of a 3D model of a target from the perspective of a tip of a catheter and its roll and articulation, the detection of which is described herein, two-dimensional (2D) fluoroscopic, CT, PET, or MRI images view showing the catheter, and a target mark, which corresponds to the 3D model of the target. User interface 616 may be further configured to display the target mark in different colors depending on whether the catheter tip is aligned with the target in three dimensions.

[0045] Network interface 608 may be configured to connect to a network such as a local area network (LAN) consisting of a wired network and / or a wireless network, a wide area network (WAN), a wireless mobile network, a Bluetooth network, and / or the Internet. Network interface 608 may be used to connect between workstation 601 and imaging device 615. NetworkPatent ApplicationAttorney Reference No. A0012265W001 (00017-01269PCT00) interface 608 may also be used to receive image data 614. Input device 610 may be any device by which a user may interact with workstation 601, such as, for example, a mouse, keyboard, foot pedal, touch screen, and / or voice interface. Output module 612 may include any connectivity port or bus, such as, for example, parallel ports, serial ports, universal serial busses (USB), or any other similar connectivity port known to those skilled in the art.EXAMPLES

[0046] In accordance with aspects of the disclosure, the following examples are presented.

[0047] Example 1 - A catheter subassembly including a polytetrafluoroethylene (PTFE) tube; a pair of coil carriers disposed on the PTFE tube; a pair of electromagnetic (EM) sensors, each EM sensor secured to one of the pair of coil carriers.

[0048] Example 2 - The catheter subassembly of Example 1, wherein each coil carrier includes a sensor slot configured to receive one EM sensor of the pair EM sensors.

[0049] Example 3 - The catheter subassembly of one of examples 1-3 further comprising a pair of PTFE tubes configured to receive a twisted pair of wires extending from each EM sensor.

[0050] Example 4 - The catheter subassembly of Example 3 wherein one coil carrier of the pair of coil carriers includes a wire slot configured to receive a twisted pair of wires extending from one EM sensor of the pair of EM sensors.

[0051] Example 5 - The catheter subassembly of one of Examples 1-4, wherein the PTFE tube is configured for advancement over a metallic braid.

[0052] Example 6 - The catheter subassembly of one of Examples 1-5, wherein the pair of EM sensors are micro coil sensors.

[0053] Example 7 - The catheter subassembly of Example 6, wherein a first of the pair of micro coils sensors is oriented 180 degrees form the orientation of a second of the pair of micro coil sensors.

[0054] Example 8 - The catheter subassembly of one of Examples 1-4, wherein a first of the pair of EM sensors is micro coil sensor and a second of the pair of EM sensors is an air coil.

[0055] Example 9 - A catheter system including a catheter, a first 5-degree of freedom (5 DOF) micro coil sensor formed on a distal end of the catheter and configured to detect an electromagnetic field and generate a first signal, a second 5 DOF sensor formed on the catheter proximally of the first 5 DOF micro coil sensor configured to detect the electromagnetic fieldPatent ApplicationAttorney Reference No. A0012265W001 (00017-01269PCT00) and generate a second signal, and an application stored in a memory including instructions that when executed a processor receive the first signals and the second signals and determine a location and orientation of the catheter in 6-degrees of freedom.

[0056] Example 10 - The catheter system of Example 9, wherein the second 5 DOF sensor is an air coil sensor.

[0057] Example 11 - The catheter system of Example 9, wherein the second 5 DOF sensor is a micro coil sensor.

[0058] Example 12 - The catheter system of one of Examples 9-11, wherein the application detects an articulation of the catheter based on the first and second signals.

[0059] Example 13 - The catheter system of one of Examples 9-12, wherein the application generates a representation of the catheter and displays the representation on one or more of intraprocedural images, preprocedural images, or models generated from the intraprocedural images or the preprocedural images.

[0060] Example 14 - The catheter system of one of Examples 9-12 further comprising at least one coil carrier.

[0061] Example 15 - The catheter system of one of Example 9-12, wherein the catheter includes a polytetrafluoroethylene (PTFE) tube defining a lumen of the catheter and configured to receive a twisted pair of wires extending from the first 5 DOF micro coil sensor or the second 5 DOF sensor.

[0062] Example 16 - A catheter including a polytetrafluoroethylene (PTFE) tube defining a lumen of the catheter; a reflow layer disposed over the inner PTFE tube; a braid layer the disposed on the inner reflow layer; a sensor subassembly disposed on the braid layer, the sensor subassembly including a PTFE tube, a pair of coil carriers, and a pair of electromagnetic (EM) sensors; and an outer jacket layer disposed on the sensor subassembly.

[0063] Example 17 - The catheter of Example 16, wherein the EM sensors are micro coil sensors.

[0064] Example 18 - The catheter of Examples 16 or 17, wherein each of the pair of coil carriers include a slot for receiving one of the pair of EM sensors.

[0065] Example 19 - The catheter of one of Examples 16-18, wherein the sensor subassembly further comprises a pair of PTFE tubes configured to receive a twisted pair of wires extending from each of the pair of sensors.Patent ApplicationAttorney Reference No. A0012265W001 (00017-01269PCT00)

[0066] Example 20 - The catheter of one of Examples 16-19, wherein the outer jacket secures the sensor subassembly to the braid layer.

[0067] Although embodiments have been described in detail with reference to the accompanying drawings for the purpose of illustration and description, it is to be understood that the inventive processes and apparatus are not to be construed as limited. It will be apparent to those of ordinary skill in the art that various modifications to the foregoing embodiments may be made without departing from the scope of the disclosure.

Claims

Patent ApplicationAttorney Reference No. A0012265W001 (00017-01269PCT00)We claim:

1. A catheter subassembly comprising: a polytetrafluoroethylene (PTFE) tube; a pair of coil carriers disposed on the PTFE tube; and a pair of electromagnetic (EM) sensors, each EM sensor secured to one of the pair of coil carriers.

2. The catheter subassembly of claim 1, wherein each coil carrier includes a sensor slot configured to receive one EM sensor of the pair EM sensors.

3. The catheter subassembly of one of claims 1-2 further comprising a pair of PTFE tubes configured to receive a twisted pair of wires extending from each EM sensor.

4. The catheter subassembly of claim 3 wherein one coil carrier of the pair of coil carriers includes a wire slot configured to receive a twisted pair of wires extending from one EM sensor of the pair of EM sensors.

5. The catheter subassembly of one of claims 1-4, wherein the PTFE tube is configured for advancement over a metallic braid.

6. The catheter subassembly of one of claims 1-5, wherein the pair of EM sensors are micro coil sensors.

7. The catheter subassembly of claim 6, wherein a first of the pair of micro coils sensors is oriented 180 degrees form the orientation of a second of the pair of micro coil sensors.

8. The catheter subassembly of one of claims 1-4, wherein a first of the pair of EM sensors is micro coil sensor and a second of the pair of EM sensors is an air coil.

9. A catheter system comprising:Patent ApplicationAttorney Reference No. A0012265W001 (00017-01269PCT00) a catheter; a first 5-degree of freedom (5 DOF) micro coil sensor formed on a distal end of the catheter and configured to detect an electromagnetic field and generate a first signal; a second 5 DOF sensor formed on the catheter proximally of the first 5 DOF micro coil sensor configured to detect the electromagnetic field and generate a second signal; and an application stored in a memory including instructions that when executed a processor receive the first signals and the second signals and determine a location and orientation of the catheter in 6-degrees of freedom.

10. The catheter system of claim 9, wherein the second 5 DOF sensor is an air coil sensor.11 . The catheter system of claim 9, wherein the second 5 DOF sensor is a micro coil sensor.

12. The catheter system of one of claims 9-11, wherein the application detects an articulation of the catheter based on the first and second signals.

13. The catheter system of one of claims 9-12, wherein the application generates a representation of the catheter and displays the representation on one or more of intraprocedural images, preprocedural images, or models generated from the intraprocedural images or the preprocedural images.

14. The catheter system of one of claims 9-12 further comprising at least one coil carrier.

15. The catheter system of one of claim 9-12, wherein the catheter includes a poly tetrafluoroethylene (PTFE) tube defining a lumen of the catheter and configured to receive a twisted pair of wires extending from the first 5 DOF micro coil sensor or the second 5 DOF sensor.

Images