Circular navigation catheter with surface-mounted inductive navigation sensors

Abstract

To provide a catheter.SOLUTION: A catheter is presented herein which includes inductive coils which conform to the curved surface of a tubular catheter body and collectively can function as a three-axis sensor during an intravascular and / or intracardiac treatment. The inductive coils can be fabricated on a flexible circuit substrate and affixed to the tubular catheter body. The catheter can include a distal portion that can be moved into a circular shape ("lasso") when within the vasculature or the heart. The inductive coils can be positioned around the circular shape such that a position and orientation of the distal portion can be determined in three dimensions when the distal portion is within a known fluctuating magnetic field.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] This application relates generally to electronic circuits, and more particularly to electronic circuits for magnetic field sensors. This application also relates to catheters that include magnetic field sensors. [Background technology]

[0002] A magnetic field can be sensed by placing a conductive coil within the magnetic field and observing the current and / or voltage induced in the coil by changes in the magnetic field aligned with the axis of the conductive coil. Because a current is induced in the conductive coil, such coils are also called induction coils. The relative position of a sensor containing one or more induction coils can be determined with respect to a known magnetic field source by monitoring the induced current and / or voltage.

[0003] Navigation sensors including three coil arrays aligned along three orthogonal axes to determine the position and orientation of the navigation sensor in three dimensions within a known induced magnetic field are disclosed, for example, in U.S. Pat. Nos. 10,330,742 and 10,677,857, each of which is incorporated by reference in its entirety into this application as if fully set forth herein, and which are attached hereto and take precedence over U.S. patent application Ser. No. 63 / 084,674.

[0004] Integrating navigational sensors into catheters suitable for intravascular and / or intracardiac procedures can involve manual manipulation of the sensors, which can result in significant manufacturing time and labor costs. Navigational sensor components can represent a significant portion of catheter material costs. Summary of the Invention [Means for solving the problem]

[0005] Presented herein is a catheter including induction coils that can conform to the curved surface of a tubular catheter body and collectively function as a three-axis sensor during intravascular procedures. The induction coils can be fabricated on a flexible circuit board and affixed to the tubular catheter body. The catheter can include a distal portion that can move into a circular shape ("lasso") when within the vasculature or heart. The induction coils can be arranged around the circular shape such that the position and orientation of the distal portion can be determined in three dimensions when the distal portion is within a known magnetic field.

[0006] An exemplary catheter may include a tubular body and a circuit. The tubular body may have a proximal shaft and a distal portion. The tubular body may have a delivery configuration in which the distal portion and the proximal shaft are aligned along a longitudinal axis. The proximal shaft may be manipulated to deliver the distal portion through the vasculature. The distal portion may have a cylindrical surface with a curvature about the longitudinal axis when the tubular body is in the delivery configuration. The circuit may include a first inductive sensor, a second inductive sensor, and a third inductive sensor. The sensors may collectively be used to determine the position and orientation of the distal portion in three dimensions when the distal portion is within a known magnetic field. In other words, the sensors may collectively function as a triaxial sensor. The circuit may be affixed to a cylindrical surface such that the first inductive sensor, the second inductive sensor, and the third inductive sensor each conform to the curvature of the cylindrical surface.

[0007] The tubular body can have a deployed configuration in which the distal portion has a generally circular shape. The circular shape can be generally perpendicular to a longitudinal axis defined by the proximal shaft of the tubular body. The tubular body can be movable from the delivery configuration to the deployed configuration via manipulation of the proximal shaft. When the distal portion is in the generally circular shape, the first inductive sensor, the second inductive sensor, and the third inductive sensor can be spaced approximately equidistant from one another around the periphery of the generally circular shape. Generally, the circular shape can have a circumference measuring about 50 millimeters.

[0008] The catheter may further include a support member extending through a tubular lumen in the distal portion of the tubular body. The tubular body may include a flexible polymeric material. The support member may include a shape memory material. The shape memory material may have a predetermined shape that is approximately the same as a generally circular shape. The catheter may further include a contraction wire extending through the tubular lumen of the tubular body in the distal portion. Moving the contraction wire may form the distal portion into the generally circular shape.

[0009] The first inductive sensor, the second inductive sensor, and the third inductive sensor may each not include any inductive coil surrounding the cylindrical surface.

[0010] The first inductive sensor may include a first inductive coil that spirals substantially parallel to the cylindrical surface so that the first inductive coil conforms to the cylindrical surface. The second inductive sensor may include a second inductive coil that spirals substantially parallel to the cylindrical surface so that the second inductive coil conforms to the cylindrical surface. The third inductive sensor may include a third inductive coil that spirals substantially parallel to the cylindrical surface so that the third inductive coil conforms to the cylindrical surface.

[0011] The first induction coil may include a first coil, a second coil, a third coil, and a fourth coil arranged in a specific arrangement. The second induction sensor and / or the third induction sensor may each include four coils arranged in a similar manner. The first, second, third, and fourth coils may be arranged as follows: The first coil may be disposed on a first side of the cylindrical surface and may include a central terminal. The second coil may be disposed on a second side of the cylindrical surface, approximately 180° around the cylindrical surface from the first side, and may also include a central terminal. The first coil may be spiraled in the opposite direction to the second coil. The third coil may be disposed on the first side of the cylindrical surface. The first and third coils may be arranged so that a majority of the first coil overlaps a majority of the third coil. The third coil may include a central terminal in direct electrical contact with the central terminal of the first coil. The third coil may be spiraled in the opposite direction to the first coil. The fourth coil may be disposed on a second side of the cylindrical surface. The second coil and the fourth coil may be disposed such that a majority of the second coil overlaps a majority of the fourth coil. The fourth coil may include a central terminal in direct electrical contact with a central terminal of the second coil. The fourth coil may be spiraled in the opposite direction to the second coil. The third coil may be spiraled in the opposite direction to the fourth coil. The third coil and the fourth coil may be constrained between two electrically insulating, substantially parallel, arcuate surfaces.

[0012] The catheter may further include conductive wiring to the coils. The first conductive wiring may be in direct electrical contact with the first coil and may extend from the first coil to the proximal shaft. The second conductive wiring may be in direct electrical contact with the second coil and may extend from the second coil to the proximal shaft. The third conductive wiring may be in direct electrical contact with the third coil and may extend from the third coil to the proximal shaft. The first and third conductive wiring may be arranged such that a majority of the first conductive wiring overlaps a majority of the third conductive wiring. The fourth conductive wiring may be in direct electrical contact with the fourth coil and may extend from the fourth coil to the proximal shaft. The second and fourth conductive wiring may be arranged such that a majority of the second conductive wiring overlaps a majority of the fourth conductive wiring. The fourth conductive wiring may be electrically connected to the third conductive wiring near the proximal shaft. Similarly, the catheter may include conductive wiring to the coil of the second inductive sensor and / or the coil of the third inductive sensor.

[0013] The circuit may include an insulating substrate, a lower layer, an insulating intermediate layer, and an upper layer. The insulating substrate may be fixed to the cylindrical surface. The lower layer may be above the insulating substrate and may include a third coil, a third conductive wire, a fourth coil, and a fourth conductive wire. The insulating intermediate layer may be above the lower layer and may include a via extending therethrough. The via may facilitate direct electrical contact between the central terminal of the first coil and the central terminal of the third coil, and may facilitate direct electrical contact between the central terminal of the second coil and the central terminal of the fourth coil. The upper layer above the insulating intermediate layer may include the first coil, the first conductive wire, the second coil, and the second conductive wire. The circuit may further include an insulating upper layer above the upper layer. Similarly, corresponding coils and wires of the second inductive sensor and / or the third inductive sensor may be disposed within the lower and upper layers of the circuit.

[0014] The catheter may further include contact pads and wires connecting to the coil. A first contact pad connected to a first conductive trace may be disposed in an upper layer of the circuit at or near the proximal shaft. A first wire may be soldered to the first contact pad and may extend through the proximal shaft to the proximal end of the tubular body. A second contact pad connected to a second conductive trace may be disposed in an upper layer of the circuit at or near the proximal shaft. A second wire may be soldered to the second contact pad and may extend through the proximal shaft to the proximal end of the tubular body. Similarly, the catheter may include contact pads and wires to a second inductive sensor and / or a third inductive sensor.

[0015] The inductive coils of the first inductive sensor, the second inductive sensor, and the third inductive sensor may each spiral around a corresponding coil axis such that the corresponding coil axis is approximately perpendicular to the cylindrical surface. Each of the inductive coils may have a respective height measured in the direction of the corresponding coil axis and a respective width measured perpendicular to the corresponding coil axis. The width may be at least 10 times greater than the height.

[0016] An exemplary method for designing, building, or assembling a catheter may include one or more of the following steps, performed in various orders, as will be understood by those skilled in the art following the teachings herein. The method may include fabricating a multilayer flexible circuit having a first coil arrangement, a second coil arrangement, and a third coil arrangement. The fabrication may result in the first coil arrangement, the second coil arrangement, and the third coil arrangement being linearly arranged to define a longitudinal axis of the multilayer flexible circuit. Each of the first coil arrangement, the second coil arrangement, and the third coil arrangement may include four corresponding coils. For each of the coil arrangements, each of the four coils may include a corresponding central terminal. The four coils may be arranged such that each of the four coils is adjacent to an adjacent stacked coil and an adjacent coplanar coil. The four coils may be arranged such that the central terminal of each of the four coils is in direct electrical contact with an adjacent stacked coil.

[0017] The method can include securing a multilayer flexible circuit to a cylindrical surface of a tubular catheter body. As a result of the securing, a longitudinal axis of the multilayer flexible circuit can be longitudinally aligned with the tubular catheter body. The flexible circuit can have an arcuate cross-section passing through each of the first coil array, the second coil array, and the third coil array, the cross-section being perpendicular to the longitudinal axis.

[0018] The method may include securing the multi-layer flexible circuit to the cylindrical surface such that each of the four coils is centered approximately 180° around the circumference of the tubular body from its adjacent coplanar coil.

[0019] The method may include forming a distal portion of the tubular catheter body in a substantially circular shape.

[0020] The method may include securing the multi-layer flexible circuit to the cylindrical surface such that when the distal portion is in a substantially circular shape, the first coil array, the second coil array, and the third coil array are each spaced approximately equidistant from one another around the generally circular shape.

[0021] The method may include configuring a proximal shaft of a tubular catheter body such that a distal portion of the tubular catheter is movable from a substantially straight shape to a substantially circular shape by manipulation of the proximal shaft.

[0022] The method can include forming a distal portion of the tubular catheter body in a substantially circular shape, such that the substantially circular shape has a circumference measuring approximately 50 millimeters.

[0023] The method may include extending a support member through a tubular lumen of the tubular catheter within the distal portion.

[0024] The method can include molding a shape memory material of the support member to have a predetermined shape that approximates a generally circular shape.

[0025] The method may include extending a contraction wire through a tubular lumen in the distal portion such that the contraction wire is movable to change the shape of the distal portion to a generally circular shape.

[0026] The method may include securing the multi-layer flexible circuit to the cylindrical surface such that the first coil array, the second coil array, and the third coil array each do not include any inductive coils surrounding the cylindrical surface.

[0027] The method may include securing a multi-layer flexible circuit to a cylindrical surface such that a first induction coil array has a first induction coil that spirals substantially parallel to the cylindrical surface so that the first induction coil conforms to the cylindrical surface. The method may include securing a multi-layer flexible circuit to a cylindrical surface such that a second coil array has a second induction coil that spirals substantially parallel to the cylindrical surface so that the second induction coil conforms to the cylindrical surface. The method may include securing a multi-layer flexible circuit to a cylindrical surface such that a third induction coil array has a third induction coil that spirals substantially parallel to the cylindrical surface so that the third induction coil conforms to the cylindrical surface.

[0028] The method may include securing a multilayer flexible circuit to a cylindrical surface so that a first induction coil array has coils arranged in a specific arrangement. The first coil may be disposed on a first side of the cylindrical surface. The second coil may be disposed on a second side of the cylindrical surface, approximately 180° around the cylindrical surface from the first side, with the first and second coils being adjacent coplanar coils (e.g., coplanar if the circuit were flat before being secured to the cylindrical surface). The third coil may be disposed on the first side of the cylindrical surface so that a majority of the first coil overlaps a majority of the third coil, such that the first and third coils are adjacent stacked coils electrically joined at their corresponding central terminals. The third coil may be spiral in the opposite direction to the first coil. The fourth coil may be disposed on the second side of the cylindrical surface such that a majority of the second coil overlaps a majority of the fourth coil, such that the second coil and the fourth coil are adjacent stacked coils electrically joined at their corresponding central terminals. The fourth coil may be spiral in the opposite direction to the second coil. The third coil and the fourth coil may be adjacent coplanar coils.

[0029] The method can include securing the multi-layer flexible circuit to a cylindrical surface such that the first coil spirals in an opposite direction from the second coil and the third coil spirals in an opposite direction from the fourth coil.

[0030] The method can include constraining the third coil and the fourth coil between two arcuate surfaces that are electrically insulating and substantially parallel.

[0031] The method may include fabricating a multi-layer flexible circuit such that a first conductive trace is in direct electrical contact with the first coil and extends from the first coil to the proximal shaft. The method may include fabricating a multi-layer flexible circuit such that a second conductive trace is in direct electrical contact with the second coil and extends from the second coil to the proximal shaft. The method may include fabricating a multi-layer flexible circuit such that a third conductive trace is in direct electrical contact with the third coil and extends from the third coil to the proximal shaft, with a majority of the first conductive trace overlapping a majority of the third conductive trace. The method may include fabricating a multilayer flexible circuit such that the fourth conductive trace is in direct electrical contact with the fourth coil, the fourth conductive trace extends from the fourth coil to the proximal shaft, a majority of the second conductive trace overlaps a majority of the fourth conductive trace, and the fourth conductive trace is in electrical contact with a third conductive trace proximate the proximal shaft.

[0032] The method may include fabricating a multilayer flexible circuit such that the multilayer flexible circuit includes an insulating substrate, a lower layer above the insulating substrate, an insulating intermediate layer above the lower layer, and an upper layer above the insulating intermediate layer. The lower layer may include a third coil, a third conductive trace, a fourth coil, and a fourth conductive trace. The insulating intermediate layer may include a via therethrough that facilitates direct electrical contact between the central terminal of the first coil and the central terminal of the third coil, and between the central terminal of the second coil and the central terminal of the fourth coil. The upper layer may include a first coil, a first conductive trace, a second coil, and a second conductive trace.

[0033] The method may include securing an insulating substrate of a multi-layer flexible circuit to a cylindrical surface of a tubular catheter body.

[0034] The method may include securing an insulating top layer over an upper layer of the multi-layer flexible circuit.

[0035] The method may include fabricating a multilayer flexible circuit such that the multilayer flexible circuit includes a first contact pad and a second contact pad, each disposed in an upper layer near the proximal shaft. The method may include soldering a first wire to the first contact pad. The method may include extending the first wire through the tubular catheter body to the proximal end of the tubular catheter body. The method may include soldering a second wire to the second contact pad. The method may include extending the second wire through the tubular catheter body to the proximal end of the tubular catheter body.

[0036] An exemplary method for intracardiac diagnosis may include one or more of the following steps, performed in various orders, as will be understood by one of ordinary skill in the art following the teachings herein. The method may include manipulating a proximal shaft of a catheter to position a distal portion of the catheter within the heart. The method may include receiving position signals from an inductive coil array affixed to a cylindrical surface of the distal portion. The coil array may be formed to have an arcuate cross-section as a result of being affixed to the cylindrical surface. The method may include determining a position and orientation of the distal portion based at least in part on, or solely on, the position signals. The method may include determining a three-dimensional position and three-dimensional orientation of the distal portion based at least in part on, or solely on the position signals.

[0037] The method may include forming a distal portion of the catheter into a substantially circular shape such that each of the inductive coil arrays is disposed about the periphery of the circular shape.

[0038] The method may include determining a three-dimensional position based at least in part on two or more of the position signals. The position signals may not include sufficient information for the three-dimensional position to be determined based on only one position signal, in which case multiple position signals may be used to calculate the three-dimensional position and orientation of the distal portion of the catheter. The method may include determining the three-dimensional position and orientation based on three position signals from three coil arrays spaced apart from one another on the distal portion. The three coil arrays may be arranged around a circular shape.

[0039] An exemplary multilayer flexible circuit may include three coil arrays, each having four coils, each having a central terminal. The three coil arrays may be linearly arranged to define a longitudinal axis of the multilayer flexible circuit. In each coil array, the four coils of that array may be arranged such that each of the four coils is adjacent to an adjacent stacked coil and an adjacent coplanar coil. The central terminal of each of the four coils may be in direct electrical contact with the adjacent stacked coil. [Brief explanation of the drawings]

[0040] While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter described herein, the subject matter will be better understood from the following description of specific embodiments read in conjunction with the accompanying drawings, in which like reference numerals identify the same elements. [Figure 1A] 1 illustrates an exemplary catheter in a deployed configuration, according to an aspect of the present invention. [Figure 1B] 1 illustrates a catheter in a delivery configuration, according to an aspect of the present invention. [Figure 2A] 1A and 1B show two exemplary cross sections of the catheter shown in FIGS. 1A and 1B, according to an embodiment of the present invention. [Figure 2B] 1A and 1B show two exemplary cross sections of the catheter shown in FIGS. 1A and 1B, according to an embodiment of the present invention. [Figure 3A]10A-10C show, in combination, an inductive sensor that can be used with a catheter according to an aspect of the present invention. [Figure 3B] 10A-10C show, in combination, an inductive sensor that can be used with a catheter according to an aspect of the present invention. [Figure 4A] FIG. 1 is a diagram of an exemplary circuit that can be used with a catheter, in accordance with aspects of the present invention. [Figure 4B] 4B is a cross-sectional view of the circuit shown in FIG. 4A according to an embodiment of the present invention. [Figure 5A] FIG. 4B is a diagram of a first coil arrangement of a first inductive sensor of the circuit shown in FIG. 4A in accordance with an embodiment of the present invention. [Figure 5B] FIG. 4B is a diagram of a first coil arrangement of a first inductive sensor of the circuit shown in FIG. 4A in accordance with an embodiment of the present invention. [Figure 5C] FIG. 4B is a diagram of a first coil arrangement of a first inductive sensor of the circuit shown in FIG. 4A in accordance with an embodiment of the present invention. [Figure 6A] FIG. 4B is a diagram of a second coil arrangement of a second inductive sensor of the circuit shown in FIG. 4A in accordance with an embodiment of the present invention. [Figure 6B] FIG. 4B is a diagram of a second coil arrangement of a second inductive sensor of the circuit shown in FIG. 4A in accordance with an embodiment of the present invention. [Figure 6C] FIG. 4B is a diagram of a second coil arrangement of a second inductive sensor of the circuit shown in FIG. 4A in accordance with an embodiment of the present invention. [Figure 7A] FIG. 4B is a diagram of a third coil arrangement of a third inductive sensor of the circuit shown in FIG. 4A in accordance with an embodiment of the present invention. [Figure 7B] FIG. 4B is a diagram of a third coil arrangement of a third inductive sensor of the circuit shown in FIG. 4A in accordance with an embodiment of the present invention. [Figure 7C] FIG. 4B is a diagram of a third coil arrangement of a third inductive sensor of the circuit shown in FIG. 4A in accordance with an embodiment of the present invention. [Figure 8A] FIG. 4C is a diagram of wiring and contact pads of the circuit shown in FIGS. 4A and 4B, according to an embodiment of the present invention. [Figure 8B] FIG. 4C is a diagram of wiring and contact pads of the circuit shown in FIGS. 4A and 4B, according to an embodiment of the present invention. [Figure 8C]FIG. 4C is a diagram of wiring and contact pads of the circuit shown in FIGS. 4A and 4B, according to an embodiment of the present invention. [Figure 9A] FIG. 10 is a diagram of another exemplary circuit that can be used with a catheter, in accordance with aspects of the present invention. [Figure 9B] FIG. 10 is a diagram of another exemplary circuit that can be used with a catheter, in accordance with aspects of the present invention. [Figure 9C] FIG. 10 is a diagram of another exemplary circuit that can be used with a catheter, in accordance with aspects of the present invention. [Figure 10A] 10A-10C are diagrams of additional exemplary catheters in accordance with aspects of the present invention. [Figure 10B] 10A-10C are diagrams of additional exemplary catheters in accordance with aspects of the present invention. [Figure 11] 1 is a diagram of an exemplary catheter-incorporated procedure in accordance with aspects of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0041] As used herein, the term "about" or "approximately" with respect to any numerical value or range of values ​​indicates a suitable dimensional tolerance that enables a portion of a component or a collection of components to function in accordance with its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of values ​​of ±20% of the recited value, for example, "about 90%" may refer to a range of values ​​of 71% to 99%.

[0042] 1A and 1B show an exemplary catheter 100 including inductive sensors 120, 140, 160, which include inductive coils that conform to the curved surface of the tubular catheter body 103 (specifically, the cylindrical surface 183 of the distal portion 108 of the tubular body 103) and collectively can function as a triaxial sensor during an intravascular procedure. The inductive sensors 120, 140, 160 can be fabricated on a flexible circuit 110 and secured to the tubular catheter body 103. As shown in FIG. 1A, the distal portion 108 of the tubular body 103 can be moved to a generally circular shape when within the vasculature or heart. The generally circular shape can be slightly spiral ("lasso") shaped. The circular shape can be curved in a clockwise or counterclockwise direction. The inductive sensors 120, 140, 160 may be arranged around a circular shape such that the position and orientation of the distal portion 108 can be determined in three dimensions when the distal portion 108 is within a known, varying magnetic field.

[0043] 1B shows the tubular body 103 of the catheter 100 in a delivery configuration in which the distal portion 108 and the proximal shaft 106 are aligned along a longitudinal axis LL. The cylindrical surface 183 of the distal portion 108 curves about the longitudinal axis when the tubular body 103 is in the delivery configuration. The circuit 110 can be secured to the cylindrical surface 183 such that the first inductive sensor 120, the second inductive sensor 140, and the third inductive sensor 160 each conform to the curvature of the cylindrical surface.

[0044] The catheter 100 may include a control handle 101 secured to the proximal end 102 of the tubular body 103, which may be moved to push the tubular body 103 distally through the vasculature. In some embodiments, the control handle 101 may also be used to move the distal portion 108 from the delivery configuration shown in FIG. 1B to the deployed configuration shown in FIG. 1A , and vice versa, similar to a multi-function catheter handle and corresponding catheter such as those described in U.S. Patent No. 6,987,995, which is incorporated by reference in its entirety into this application as if fully set forth herein, and which is attached to this appendix and which precedes U.S. Patent Application No. 63 / 084,674, or similar to an alternative system capable of moving the distal portion 108 to an expanded, deployed configuration.

[0045] As shown in FIG. 1A , the tubular body 103 can have a deployed configuration in which the distal portion 108 has a generally circular shape. The circular shape can be generally perpendicular to the longitudinal axis LL defined by the proximal shaft 106 of the tubular body. Alternatively, the circular shape can be aligned with the longitudinal axis LL or at an oblique angle relative to the longitudinal axis LL. As shown, the distal portion 108 forms a lasso shape that passes through and is generally aligned with a plane PP that is perpendicular to the longitudinal axis LL of the shaft 106. Regardless of the angle of the circular shape relative to the longitudinal axis LL, when the distal portion 108 is in the generally circular shape, the first inductive sensor 120, the second inductive sensor 140, and the third inductive sensor 160 can be spaced approximately equidistant from one another around the periphery of the generally circular shape.

[0046] The proximal shaft 106 may have an elongated tubular structure. The proximal shaft 106 may have a single, axial, or central lumen. The proximal shaft 106 is flexible, i.e., bendable, but substantially incompressible along its length. The proximal shaft 106 may be of any suitable construction and made of any suitable material. In some embodiments, the proximal shaft 106 has an outer polymer wall with an internal braided metal mesh. The proximal shaft 106 may have sufficient structural integrity so that when the control handle 101 is rotated, the tubular body 103, including the proximal shaft 106 and distal portion 108, rotates in a corresponding manner. The outer diameter of the proximal shaft 106 is preferably about 8 French or about 7 French.

[0047] The useful length of catheter 100, i.e., the portion that can be inserted into the body, can vary based on the patient's anatomy and treatment procedure. For most treatments, the useful length can be from about 110 centimeters (cm) to about 120 cm. The length of distal portion 108 is a relatively smaller portion of the useful length, preferably from about 3.5 cm to about 10 cm, and more preferably from about 5 cm to about 6.5 cm.

[0048] In some embodiments, the distal portion 108 can have a portion aligned with the longitudinal axis LL, measuring from about 3 millimeters (mm) to about 12 mm when the distal portion 108 is in a substantially circular shape. The distal end 104 of the tubular body 103 may or may not overlap the distal portion 108 when in a circular shape (e.g., compare FIG. 1A with FIGS. 10A and 10B). The substantially circular shape can have a circumference measuring approximately equal to the length of the distal portion 108, or it can deviate somewhat from the length of the distal portion 108. Furthermore, in some embodiments, the circumference of the circular shape can be altered within the patient via manipulation of the control handle 101. The circular shape can have a circumference measuring from about 3 cm to about 8 cm, more preferably from about 4 cm to about 6 cm, and more preferably about 5 cm.

[0049] The proximal shaft 106 and distal portion 108 may be bonded together with an adhesive or the like. In some embodiments, the bond 105 may include a spacer similar to that described in U.S. Patent No. 5,964,757, which is incorporated herein by reference in its entirety as if fully set forth herein and which is attached hereto and supersedes U.S. Patent Application No. 63 / 084,674.

[0050] 1A and 1B, the distal portion 108 may further include mapping electrodes and associated support structures. For example, the catheter 100 may include a mapping electrode 188 shown in FIG. 10B. The mapping electrode 188 may be positioned or otherwise configured to measure electrical signals from tissue in contact with the distal portion 108.

[0051] 2A and 2B illustrate an exemplary cross-section of the catheter 100 shown in FIGS. 1A and 1B. The cross-section is shown through the second inductive sensor 140. The first inductive sensor 120 and the third inductive sensor 160 may each have a similar cross-section. The catheter 100 may include a support member 184 extending through a tubular lumen in the distal portion 108 of the tubular body 103. While the distal portion 108 is illustrated as having a single lumen, the distal portion 108 may include additional lumens, and the number of lumens may vary along the length of the distal portion 108. The interior of the distal portion 108 may be configured to accommodate the support member 184, the contraction wire 186 (FIG. 2A), electrical conductors, and other desired wires, cables, and / or tubes. Other suitable configurations for the interior of the distal portion 108 are described in U.S. Pat. No. 6,987,995, which is incorporated herein by reference in its entirety as if fully set forth herein, and which is attached hereto and supersedes U.S. Patent Application No. 63 / 084,674.

[0052] The support member 184 may include a shape memory material that may have a shape that generally corresponds to the generally circular shape of the distal portion in the deployed configuration, as shown in Figure 1A.

[0053] FIG. 2A shows a catheter 100 that further includes a contraction wire 186 extending through the lumen. The contraction wire 186 can extend to the distal end 104 of the tubular body 103 or through only a portion of the distal portion 108. The distal portion 108 of the tubular body 103 can include a flexible polymer tube 182 that is flexible enough to move when the contraction wire 186 is pulled and / or the support member 184 is reshaped. If the catheter 100 includes a contraction wire 186, the support member 184 can include a shape memory material to achieve the circular shape shown in FIG. 1A, but need not include a shape memory material. Moving the contraction wire 186 can form the distal portion 108 into a generally circular shape. If the support member 184 includes a shape memory material and the catheter 100 includes a contraction wire 186, the contraction wire can function to move the distal portion 108 into a shape that deviates from the predetermined shape of the support member 184.

[0054] 2B shows the catheter 100 without the contraction wire 186 through at least a portion of the distal portion 108 of the tubular body 103 of the catheter 100. The shape of the distal portion 108 may be determined by the shape of the support member 184.

[0055] 2A and 2B show a cross section of the circuit 110 through the second inductive sensor 140. The coils 141-144 of the second inductive sensor 140 are spiraled substantially parallel to the cylindrical surface 183 of the polymer tube 182. The coils 141-144 conform to the cylindrical surface 183 of the polymer tube 182 by having the circuit 110 wrapped around and secured to the cylindrical surface 183. Similarly, the coils 121-124, 161-164 of the first inductive sensor 120 and the third inductive sensor 160 may conform to the cylindrical surface 183 of the polymer tube 182 by having the circuit 110 wrapped around and secured to the cylindrical surface 183. Each of the first inductive sensor 120, the second inductive sensor 140, and the third inductive sensor 160 may not include any inductive coils surrounding a cylindrical surface. Each of the coils 121-124, 141, 144, 161-164 may be constrained between insulating layers having an arcuate cross section.

[0056] The coil may be helical about a radial axis (r) that is perpendicular to the cylindrical surface 183. When in the deployed configuration shown in Figure 1A, the coil may be aligned with the longitudinal axis LL of the shaft 106, as shown in Figures 2A and 2B. Thus, the radial axis (r) lies approximately in the plane PP of the distal portion 108, as shown in Figure 1A.

[0057] 3A and 3B show a first inductive sensor 120 associated with wires 131-134 and contact pad 130. The illustrated first inductive sensor 120 includes a first coil 121, a second coil 122, a third coil 123, and a fourth coil 124. The first coil 121 and the second coil 122 are secured to an insulating layer 116 as shown in FIG. 3A. The third coil 123 and the fourth coil 124 are secured to a substrate 114 as shown in FIG. 3B. The insulating layer 116 (FIG. 3A) may be disposed over the third coil 123 and the fourth coil 124 (FIG. 3B) to form the first inductive sensor 120. The substrate 114 and the insulating layer 116 are each formed into a cylindrical shape. The coils 121, 122, 123, and 124 conform to their respective cylindrical shapes. The second inductive sensor 140 and / or the third inductive sensor 160 may each include four coils aligned in a manner similar to the first, second, third, and fourth coils 121-124 of the first inductive sensor 120 shown.

[0058] The substrate 114 may be secured to a cylindrical surface 183 (FIGS. 2A and 2B). So configured, the first coil 121 and the second coil 122 are adjacent neighbors, and similarly, the third coil 123 and the fourth coil are adjacent neighbors. The first coil 121 and the third coil 123 are stacked neighbors, and the second coil 122 and the fourth coil 124 are stacked neighbors. Each coil includes a central terminal electrically connected to its stacked neighbors through respective vias 126, 128 (FIG. 4B) through the insulating layer 116.

[0059] 1A-2B, the first coil 121 and the second coil 122 are positioned 180° apart from each other around the cylindrical surface 183 of the distal portion 108 when the circuit 110 is secured to the catheter 100. Similarly, the third coil 123 and the fourth coil 124 are positioned 180° apart from each other around the cylindrical surface 183.

[0060] The third coil 123 may be spiraled in the opposite direction to the first coil 121. The first coil 121 and the third coil 123 may be arranged such that a majority of the first coil 121 overlaps a majority of the third coil 123. The fourth coil 124 may be spiraled in the opposite direction to the second coil 122. The second coil 122 and the fourth coil 124 may be arranged such that a majority of the second coil 122 overlaps a majority of the fourth coil 124. The first coil 121 may be spiraled in the opposite direction to the second coil 122. The third coil 123 may be spiraled in the opposite direction to the fourth coil 124. The third coil 123 and the fourth coil 124 may be constrained between two arcuate surfaces 114, 116 that are electrically insulating and substantially parallel.

[0061] The circuit 110 may further include conductive wires 131-134 in the coils 121-124. The first conductive wire 131 may be in direct electrical contact with the first coil 121 and extend from the first coil 121 to the proximal shaft 106 (i.e., near the junction 105 between the distal portion 108 and the proximal shaft 106, or further toward the proximal end 102 of the tubular body 103). The second conductive wire 132 may be in direct electrical contact with the second coil 122 and extend from the second coil 122 to the proximal shaft 106. The third conductive wire 133 may be in direct electrical contact with the third coil 123 and extend from the third coil 123 to the proximal shaft 106. The first conductive trace 131 and the third conductive trace 133 may be arranged such that a majority of the first conductive trace 131 overlaps a majority of the third conductive trace 133. The fourth conductive trace 134 may be in direct electrical contact with the fourth coil 124 and extend from the fourth coil 124 to the proximal shaft 106. The second conductive trace 132 and the fourth conductive trace 134 may be arranged such that a majority of the second conductive trace 132 overlaps a majority of the fourth conductive trace 134. The fourth conductive trace 134 may be electrically connected to the third conductive trace 133 near the proximal shaft 106. By extending the third conductive wiring 133 and the fourth conductive wiring 134 to run close to the first conductive wiring 131 and the second conductive wiring 132, the wiring may act similar to a twisted pair and reduce noise in the electrical signal from the first inductive sensor 120 compared to a configuration in which the third conductive wiring 133 and the fourth wiring are shortened in the circuit 110 or otherwise routed in the circuit 110.

[0062] The geometry of the coils 121-124 and circuit 110 can be described in relation to a cylindrical coordinate system having a radial axis (r), a z-axis (z), and an azimuthal angle (θ). The radial axis (r) is aligned with the coils 121-124, similar to that shown in FIGS. 2A and 2B. The z-axis (z) is approximately coaxial with the polymer tube 182 shown in FIGS. 2A and 2B. Each of the coils 121-124 is generally curved to spiral at a constant radial distance from the z-axis. Each coil 121-124 spirals through an azimuthal angle (θ) of less than 180°, preferably greater than or equal to about 140°.

[0063] 4A is a diagram of an exemplary circuit 110 that can be used with the catheter 100. The circuit 110 is shown in a flat configuration and is flexible so that it can be wrapped around the distal portion 108 of the catheter body 103, as shown in FIGS. 1A-3B. The circuit 110 can have a length (L) sufficient to allow placement of the sensors 120, 140, 160 on the distal portion 108 of the catheter body 103, and preferably sufficient to allow placement of the contact pad array 180 within the proximal shaft 106. In one embodiment, the circuit 110 has a length (L) of approximately 20 centimeters.

[0064] The circuit 110 includes a distal section 119 that does not include conductive wiring. The distal section may be shaped or otherwise configured to help secure the circuit 110 to the cylindrical surface 183 of the distal portion 108. The distal section 119 of the circuit 110 may have a width W1 measuring approximately 0.6 mm and a length L1 of approximately 25 mm. Each of the sensors 120, 140, 160 may be positioned on a portion of the circuit 110 having a width W2 of approximately 3.2 mm and a length L2 of approximately 5 mm. The coil arrays may occupy most of the area of ​​those portions. The sensors 120, 140, 160 may be separated by intermediate sections 138, 158 having widths approximately equal to the width of the distal section 119 and lengths L3, L4 of approximately 11 mm to approximately 13 mm. In one example, the length L4 between the third sensor 160 and the second sensor 140 may be approximately 13 mm, and the length L3 between the second sensor 140 and the first sensor 120 may be approximately 11 mm. The circuit 110 may include a proximal section 178 between the third sensor 160 and the contact pad array 180. The proximal section 178 may have a length L5 measuring approximately 105 mm and a width measuring approximately the same as the distal section 119 and the intermediate sections 138, 158. The length L5 of the proximal section 178 may be sufficient to allow the contact pad array 180 to be positioned within the proximal shaft 106. The contact pad array 180 may be disposed on a section of the circuit 110 having a length L6 measuring approximately 9.25 mm and a width W3 measuring approximately 0.8 mm. The circuit 110 may include a proximal section 117 that does not have conductive traces. The proximal section 117 may have a length L7 measuring approximately 25 mm and a width W3 measuring approximately equal to the width of the section of the circuit 110 including the contact pad array 180, or may be narrower, approximately 0.6 mm.

[0065] 4A. Circuit 110 may include an insulating substrate 114, a bottom layer 112, an insulating middle layer 116, and a top layer 111. Circuit 110 may further include an insulating top layer 118 above top layer 111. Insulating substrate 114 may be secured to a cylindrical surface 183 of distal portion 108 of tubular body 103 of catheter 100 to form the cross-section shown in FIGS. 2A and 2B. Bottom layer 112 may be above insulating substrate 114 and may include third coil 123, third conductive trace 133, fourth coil 124, and fourth conductive trace 134. Insulating middle layer 116 may be above bottom layer 112 and may include vias 126, 128 extending therethrough. Vias 126, 128 may facilitate direct electrical contact between the central terminal of first coil 121 and the central terminal of third coil 123, and may facilitate direct electrical contact between the central terminal of second coil 122 and the central terminal of fourth coil 124. Upper layer 111 above insulating intermediate layer 116 may include first coil 121, first conductive trace 131, second coil 122, and second conductive trace 132.

[0066] 5A-5C are diagrams of a first coil arrangement of a first inductive sensor 120 of circuit 110. FIG. 5A shows the assembled first inductive sensor 120. FIG. 5B shows the insulating separator 116 and the first and second coils 121, 122 on the top layer 111 of circuit 110. FIG. 5C shows the substrate 114 and the third and fourth coils 123, 124 on the bottom layer 112. The coils are connected between layers 111, 112 by vias 126, 128 at the center terminals.

[0067] 6A-6C are diagrams of the second coil arrangement of the second inductive sensor 140 of the circuit 110. FIG. 6A shows the assembled second inductive sensor 140. FIG. 6B shows the insulating separator 116 and the fifth coil 141 and sixth coil 142 on the top layer 111 of the circuit 110. FIG. 6C shows the seventh coil 143 and eighth coil 144 on the substrate 114 and bottom layer 112. Wiring 131-134 from the first inductive sensor 120 is routed around the second coil arrangement of the second inductive sensor 140. The coils are connected between the layers 111, 112 by vias 146, 148 at their center terminals.

[0068] 7A-7C are diagrams of the third coil arrangement of the third inductive sensor 160 of the circuit 110. FIG. 7A shows the assembled third inductive sensor 160. FIG. 7B shows the insulating separator 116 and the ninth coil 161 and tenth coil 162 on the top layer 111 of the circuit 110. FIG. 7C shows the eleventh coil 163 and twelfth coil 164 on the substrate 114 and bottom layer 112. Wiring 131-134, 151-154 from the first inductive sensor 120 and the second inductive sensor 140 are routed around the third coil arrangement of the third inductive sensor 160. The coils are connected between the layers 111, 112 by vias 166, 168 at their center terminals.

[0069] 8A-8C are diagrams of the wiring 131-134, 151-154, 171-174 and contact pads 130, 150, 170 of circuit 110. Wires or other conductors may be soldered to contact pads 130, 150, 170 to provide electrical connection to coils 121-124, 141-144, 161-164. Such wires or conductors may extend through proximal shaft 106 to proximal end 102 of tubular body 103 to make electrical signals from sensors 120, 140, 160 accessible to equipment outside the patient.

[0070] Figure 8A shows the assembled contact pad array 180. Figure 8B shows the insulating separator 116 and the coils and traces 131, 132, 151, 152, 171, 172 from the first coil 121, second coil 122, fifth coil 141, sixth coil 142, ninth coil 161, and tenth coil 162 on the top layer 111 of the circuit 110. Contact pads 130, 150, 170 are also disposed on the insulating separator 116 and within the top layer 111. 8C shows the substrate 114 and the wires 133, 134, 153, 154, 173, 174 from the coils and wires, third coil 123, fourth coil 124, seventh coil 143, eighth coil 144, eleventh coil 163, and twelfth coil 164, on the bottom layer 112 of the circuit 110. The wires 133, 134, 153, 154, 173, 174 on the bottom layer 112 may be shortened and the wires may be lengthened to extend them below the corresponding wires 131, 132, 151, 152, 171, 172 on the top layer 111 to improve electromagnetic compatibility. Similar to twisted pairs, the wires 133, 134, 153, 154, 173, 174 on the lower layer 112 may be formed, arranged, and otherwise configured relative to the corresponding wires 131, 132, 151, 152, 171, 172 on the upper layer 111 to reduce electromagnetic radiation from the wires 131-134, 151-154, 171-174, reduce crosstalk between adjacent wires, and / or improve rejection of external electromagnetic interference.

[0071] 9A-9C are diagrams of another exemplary circuit 110a having sensors 120a, 140a, and 160a and a contact pad array 180a. The circuit 110a shown in FIGS. 9A-9C may be used in place of the circuit 110 shown in FIGS. 4A-8C. FIG. 9A is a schematic diagram of the circuit 110a. FIGS. 9B and 9C are detailed diagrams of a portion of the circuit 110a shown in FIG. 9A. The circuit 110a shown in FIGS. 9A-9C may have dimensions L, L1-L7, and W1-W3 similar to those of the circuit 110 shown in FIG. 4A. The sensors 120a, 140a, and 160a of the circuit 110a shown in FIGS. 9A-9C may be configured similarly to the sensors 120, 140, and 160 shown in FIGS. 1A-8C. The circuit 110a shown in Figures 9A-9C can be wrapped around the distal portion 108 of the catheter 100 to orient the sensors 120a, 140a, and 160a similarly to the orientation of the corresponding sensors 120, 140, and 160 of the circuit 110 shown in Figures 1A-8C. Similarly, the circuit 110a can include coils, wiring, and contact pads configured similarly to those described in connection with the circuit 110 shown in Figures 1A-8C. Differences in geometry between the circuit 110a shown in Figures 9A-9C and the circuit 110 shown in Figures 1A-8C can be accommodated using techniques understood by those skilled in the art following the teachings herein. Similarly, other suitable circuits having various geometries can be realized by those skilled in the art following the teachings herein.

[0072] Figures 10A and 10B are diagrams of additional exemplary catheters 100a, 100b. The distal portions 108a, 108b of each catheter 100a, 100b are generally circular in shape, similar to that shown and described in connection with the catheter 100 shown in Figure 1A. The catheters 100a, 100b shown in Figures 10A and 10B include circuitry 110 that includes sensors 120, 140, 160 shown in Figures 1A-8C, respectively. The catheters 100a, 100b may alternatively include the circuitry 110a shown in Figures 9A-9C, or variations of the circuitry 110, 110a described, as will be understood by those skilled in the art following the teachings herein. The respective circular shapes of the distal portions 108a, 108b of the respective catheters 100a, 100b shown in Figures 10A and 10B have a diameter D2 that may be similar to the diameter of the catheter 100 shown in Figure 1A, where diameter D2 is the circumference of the circular shape divided by π.

[0073] The catheter 100b shown in FIG. 10B includes a mapping electrode 188 disposed on the distal portion 108b. The mapping electrode 188 may be configured similarly to that described in U.S. Pat. No. 6,987,995, which is incorporated herein by reference as if fully set forth herein and which is attached to this appendix and supersedes U.S. Patent Application No. 63 / 084,674, or may be configured in another suitable configuration as would be understood by one of ordinary skill in the art. In some embodiments, a circular arrangement of the mapping electrodes 188 may enable measurement of electrical activity between the electrodes to identify ectopic beats. The size of the generally circular distal portion 108b may facilitate measurement of electrical activity around a pulmonary vein or other tubular structure at or near the heart. The distal portion 108b may have a diameter D2 generally corresponding to that of the pulmonary vein, coronary sinus, or other circular or tubular anatomical structure being diagnosed.

[0074] The mapping electrode 188 may be made of a suitable conductive material, such as platinum or gold, preferably a combination of platinum and iridium. The mapping electrode 188 includes a series of ring electrodes mounted on a polymer tube 182 of the distal portion 108 of the tubular body 103 of the catheter 100b. The mapping electrode 188 may be mounted over the circuitry 110 and over the sensors 120, 140, and 160. The distal portion 108b may optionally include a non-conductive cover disposed over the circuitry 110 and under the mapping electrode 188. The mapping electrode 188 may be secured to the distal portion 108b by glue, welding, crimping, or the like. Alternatively, the mapping electrode 188 may be formed by coating the distal portion 108b with a conductive material, such as platinum, gold, and / or iridium. The coating may be applied using sputtering, ion beam deposition, or a comparable technique. In some embodiments, each mapping electrode 188 is attached by forming a hole in the polymer tube 182, an electrode lead wire (not shown) is fed through the hole, and the mapping electrode 188 is welded in place over the lead wire and polymer tube 182. The lead wires extend through the polymer tube 182 and into the proximal shaft 106. The proximal end of each lead wire is electrically connected to a suitable connector (not shown), which is connected to an appropriate monitor or other device for receiving and displaying information received from the mapping electrodes 188. Alternatively, the mapping electrodes 188 can be formed by adding a top layer on top of the flexible circuit 110, for example, by patterning a conductor on top of the insulating top layer 118 (see FIG. 4B ).

[0075] 11 is an illustration of a medical procedure with an exemplary system 12 incorporating an exemplary catheter 100 disclosed herein, which may be configured similarly to the exemplary catheters 100, 100a-b shown herein, or variations thereof as would be understood by one of ordinary skill in the art following the teachings herein. The procedure is performed by a medical professional 14, and by way of example, the procedure in the following description is assumed to include an investigation of the electrical potential of a portion of the myocardium 16 of the heart of a human patient 18. However, the exemplary catheters 100, 100a-b may be used in other medical procedures, as would be understood by one of ordinary skill in the art.

[0076] To perform the investigation, the specialist 14 inserts the catheter 100 into a sheath 21 previously placed within the patient's lumen. The sheath 21 is positioned so that a distal portion 108 of the catheter 100 enters the heart of the patient 18. The distal portion 108 includes a position sensor 24 including three inductive sensors 120, 140, 160 as disclosed and shown herein, or variations thereof as would be understood by one of ordinary skill in the art following the teachings herein. The position sensor 24 may enable tracking of the position and orientation of the distal portion 108 of the catheter 100. The distal portion 108 may also include a mapping electrode 188 as disclosed and shown herein, or variations thereof as would be understood by one of ordinary skill in the art following the teachings herein. The mapping electrode 188 may be used to acquire electrical potentials of the myocardium 16.

[0077] The position sensor 24 includes inductive sensors 120, 140, and 160, each including a plurality of coils 121-124, 141-144, and 161-164, respectively. Although the description herein describes using the coils to sense magnetic fields, the coils may also be used to generate magnetic fields.

[0078] The system 12 may include a console 48 having a system processor 46. The console 48 may be used by the specialist 14 and may include a control unit 49 in communication with the processor 46. Software for the processor 46 may be downloaded to the processor in electronic form, for example, over a network. Alternatively or additionally, the software may be provided on a non-transitory tangible medium, such as an optical or magnetic medium, or on an electronic storage medium. Tracking (e.g., position and orientation) of the distal portion 108 of the catheter 100 may be displayed on a three-dimensional representation 60 of the heart of the patient 18 displayed on a screen 62.

[0079] To operate the system 12, the processor 46 communicates with a memory 50 having several modules used by the processor 46 to operate the system 12. As such, the memory 50 may include an electrocardiograph (ECG) module 56 that acquires and analyzes signals from the mapping electrodes 188. The memory 50 may also include a tracking module 52, which receives signals from the position sensor 24 and analyzes the signals to generate a position and orientation of the distal portion 108. The ECG module 56 and the tracking module 52 may include hardware and / or software components. The memory 50 may also include other software modules, such as a power module for measuring power on the distal portion 108 and / or an irrigation module that allows the processor 46 to control irrigation provided for the distal portion 108. For simplicity, such other modules are not shown in FIG. 11 .

[0080] In addition to receiving and analyzing signals from the position sensor 24, the tracking module 52 may also control the emitters 30, 32, 34. The emitters may be positioned proximate the myocardium 16 and configured to emit alternating magnetic fields into a region proximate the myocardium 16. The position sensor 24 may be configured to generate electrical signals that can be transmitted to the console 48 and interpreted by the tracking module 52 to determine the three-dimensional position and orientation of the distal portion 108 of the catheter 100. Each of the inductive sensors 120, 140, 160 may be configured to generate electrical signals for the position sensor 24 in response to emitted magnetic fields that intersect the coils 121-124, 141-144, 161-164 of the inductive sensors 120, 140, 160, thereby enabling the console 48 to track the distal portion 108. The Carto® system, manufactured by Biosense Webster, uses such a magnetic tracking system.

[0081] In many known magnetic tracking systems, the three inductive sensors of a position sensor are arranged orthogonally to one another, i.e., each coil of each inductive sensor is arranged along its respective coil axis, and each coil axis of an inductive sensor is orthogonal to the coil axes of the other two inductive sensors. In many known magnetic systems, the coils are either planar (spiraling in a plane with a radius extending from a central terminal) or cylindrically spiral (spiraling along the length of a cylindrical shape at a constant radius from the central axis of the cylindrical shape). As presented herein, the sensors 120, 140, 160 of exemplary catheters 100, 100a-b need not be orthogonal to one another. The coils 121-124, 141-144, 161-164 of sensors 120, 140, 160 need not be planar or cylindrically spiral. Thus, the tracking module 52 may be configured to determine the three-dimensional position of the distal portion 108 of the catheter 100 based on electrical signals from the non-orthogonal sensors 120, 140, 160 and / or electrical signals from coils that are neither planar nor cylindrical helical.

[0082] The descriptions contained herein are examples of embodiments of the present invention and are not intended to limit the scope of the invention in any way. As described herein, the present invention contemplates many variations and modifications of catheters 100, 100a-b, circuits 110, 100a, and methods of making and using them. Additional modifications that are apparent to those skilled in the art to which the present invention pertains are intended to be included within the scope of the following claims.

[0083] [Embodiment] (1) A catheter, A tubular body comprising a proximal shaft, a distal portion, and a delivery configuration in which the distal portion and the proximal shaft are aligned along a longitudinal axis, the proximal shaft is configured to be manipulated to deliver the distal portion through a vasculature; a tubular body, the distal portion comprising a cylindrical surface including a curvature about the longitudinal axis when the tubular body is in the delivery configuration; 1. A circuit comprising: a first inductive sensor, a second inductive sensor, and a third inductive sensor collectively configured to function as a three-axis sensor; the first inductive sensor comprising a first inductive coil that spirals substantially parallel to the cylindrical surface such that the first inductive coil conforms to the cylindrical surface; the second inductive sensor comprising a second inductive coil that spirals substantially parallel to the cylindrical surface such that the second inductive coil conforms to the cylindrical surface; and circuitry, wherein the third inductive sensor comprises a third inductive coil that spirals substantially parallel to the cylindrical surface such that the third inductive coil conforms to the cylindrical surface. (2) the tubular body has a deployed configuration in which the distal portion includes a generally circular shape generally perpendicular to the longitudinal axis; the tubular body is movable from the delivery configuration to the deployed configuration via manipulation of the proximal shaft; A catheter as described in embodiment 1, wherein the first inductive sensor, the second inductive sensor, and the third inductive sensor are each spaced approximately equidistant from one another around the approximately circular shape. (3) The catheter of embodiment 2, wherein the generally circular shape comprises a circumference measuring approximately 50 millimeters. (4) further comprising a support member extending through the tubular lumen of the tubular body within the distal portion; 3. The catheter of claim 2, wherein the tubular body comprises a flexible polymeric material. (5) further comprising a contraction wire extending through the tubular lumen of the tubular body within the distal portion, the contraction wire being movable to change the shape of the distal portion to the generally circular shape; A catheter as described in embodiment 4, wherein the support member comprises a shape memory material and a predetermined shape that approximates the generally circular shape.

[0084] (6) A catheter as described in embodiment 1, wherein the first inductive sensor, the second inductive sensor, and the third inductive sensor each do not include any inductive coil surrounding the cylindrical surface. (7) The first induction coil a first coil disposed on a first side of the cylindrical surface and including a central terminal; a second coil disposed on a second side of the cylindrical surface approximately 180° around the cylindrical surface from the first side, the second coil including a central terminal; a third coil disposed on the first side of the cylindrical surface such that a majority of the first coil overlaps a majority of the third coil, the third coil spiraling in an opposite direction to the first coil and including a central terminal in direct electrical contact with the central terminal of the first coil; a fourth coil disposed on the second side of the cylindrical surface, the fourth coil spiraling in the opposite direction to the second coil, the fourth coil being disposed such that a majority of the second coil overlaps a majority of the fourth coil, and the fourth coil includes a central terminal in direct electrical contact with the central terminal of the second coil. (8) The first coil is spiraled in the opposite direction to the second coil, 8. The catheter of embodiment 7, wherein the third coil is spiraled in the opposite direction to the fourth coil. (9) A catheter according to embodiment 7, wherein the third coil and the fourth coil are constrained between two arcuate surfaces that are electrically insulating and substantially parallel. (10) a first conductive trace in direct electrical contact with the first coil and extending from the first coil to the proximal shaft; a second conductive trace in direct electrical contact with the second coil and extending from the second coil to the proximal shaft; a third conductive trace in direct electrical contact with the third coil, extending from the third coil to the proximal shaft and positioned such that a majority of the first conductive trace overlaps a majority of the third conductive trace; A catheter as described in embodiment 7, further comprising a fourth conductive wiring in direct electrical contact with the fourth coil, extending from the fourth coil to the proximal shaft, arranged so that a majority of the second conductive wiring overlaps a majority of the fourth conductive wiring, and electrically connected to the third conductive wiring proximal to the proximal shaft.

[0085] (11) The circuit an insulating substrate fixed to the cylindrical surface; a lower layer above the insulating substrate, the lower layer including the third coil, the third conductive trace, the fourth coil, and the fourth conductive trace; an insulating interlayer above the lower layer with vias therethrough, the vias facilitating direct electrical contact between the central terminal of the first coil and the central terminal of the third coil, and between the central terminal of the second coil and the central terminal of the fourth coil; an upper layer above the insulating intermediate layer comprising the first coil, the first conductive trace, the second coil, and the second conductive trace; 11. The catheter of claim 10, further comprising an insulating upper layer above the upper layer. (12) a first contact pad disposed within the upper layer adjacent the proximal shaft; a first wire soldered to the first contact pad and extending through the proximal shaft to the proximal end of the tubular body; a second contact pad disposed within the upper layer adjacent the proximal shaft; A catheter as described in embodiment 11, further comprising a second wire soldered to the second contact pad and extending through the proximal shaft to the proximal end of the tubular body. (13) The catheter of embodiment 1, wherein the first induction coil, the second induction coil, and the third induction coil each spiral around a corresponding coil axis such that the corresponding coil axis is approximately perpendicular to the cylindrical surface. (14) The catheter of embodiment 13, wherein each of the first induction coils comprises a height measured in the direction of the corresponding coil axis of the first induction coil and a width measured perpendicular to the corresponding coil axis, the width being at least 10 times greater than the height. (15) A method comprising: making a multi-layer flexible circuit comprising a first coil array, a second coil array, and a third coil array; the first coil array, the second coil array, and the third coil array are linearly aligned to define a longitudinal axis of the multi-layer flexible circuit; so that each of the first coil array, the second coil array, and the third coil array comprises four coils; each of the four coils includes a central terminal, and each of the four coils is arranged adjacent to an adjacent stacked coil and an adjacent coplanar coil; and making the central terminal of each of the four coils in direct electrical contact with its adjacent stacked coil; and securing the multi-layer flexible circuit to the cylindrical surface of the tubular catheter body such that the longitudinal axis of the multi-layer flexible circuit is longitudinally aligned with the tubular catheter body and such that the flexible circuit has a corresponding arcuate cross-section perpendicular to the longitudinal axis through each of the first coil array, the second coil array, and the third coil array.

[0086] (16) The method of claim 15, further comprising securing the multilayer flexible circuit to the cylindrical surface such that each of the four coils is centered approximately 180° around the circumference of the tubular body from its adjacent coplanar coil. (17) forming a distal portion of the tubular catheter body with a circular shape; 16. The method of claim 15, further comprising: fixing the multilayer flexible circuit to the cylindrical surface such that, when the distal portion is in the circular shape, the first coil array, the second coil array, and the third coil array are spaced approximately equidistant from each other around the generally circular shape. (18) The method of claim 15, further comprising securing the multilayer flexible circuit to the cylindrical surface such that the first coil array, the second coil array, and the third coil array each do not include any inductive coils surrounding the cylindrical surface. (19) The method of claim 15, further comprising securing the multilayer flexible circuit to the cylindrical surface such that the first coil arrangement comprises a first induction coil that spirals substantially parallel to the cylindrical surface so that the first induction coil conforms to the cylindrical surface, the second coil arrangement comprises a second induction coil that spirals substantially parallel to the cylindrical surface so that the second induction coil conforms to the cylindrical surface, and the third coil arrangement comprises a third induction coil that spirals substantially parallel to the cylindrical surface so that the third induction coil conforms to the cylindrical surface. (20) A method for intracardiac diagnosis, comprising: manipulating a proximal shaft of a catheter to position a distal portion of the catheter within the heart; receiving position signals from an inductive coil array affixed to a cylindrical surface of the distal portion, the coil array being shaped to have an arcuate cross section as a result of being affixed to the cylindrical surface; and determining a position and orientation of the distal portion based at least in part on the position signal.

Claims

1. A catheter comprising: a tubular body comprising a proximal shaft and a distal portion, wherein in a delivery configuration the distal portion and the proximal shaft are aligned along a longitudinal axis; the proximal shaft is configured to be manipulated to deliver the distal portion through a vasculature; a tubular body, the distal portion comprising a cylindrical surface including a curvature about the longitudinal axis when the tubular body is in the delivery configuration; 1. A circuit comprising: a first inductive sensor, a second inductive sensor, and a third inductive sensor collectively configured to function as a three-axis sensor; the first inductive sensor comprising a first inductive coil that spirals substantially parallel to the cylindrical surface such that the first inductive coil conforms to the cylindrical surface; the second inductive sensor comprising a second inductive coil that spirals substantially parallel to the cylindrical surface such that the second inductive coil conforms to the cylindrical surface; and a circuit, wherein the third inductive sensor comprises a third inductive coil that spirals substantially parallel to the cylindrical surface such that the third inductive coil conforms to the cylindrical surface; The first induction coil a first coil disposed on a first side of the cylindrical surface and including a central terminal; a second coil disposed on a second side of the cylindrical surface approximately 180° around the cylindrical surface from the first side, the second coil including a central terminal; a third coil disposed on the first side of the cylindrical surface, the third coil spiraling in an opposite direction to the first coil, the third coil being disposed such that a majority of the first coil overlaps a majority of the third coil, and the third coil including a central terminal in direct electrical contact with the central terminal of the first coil; a fourth coil disposed on the second side of the cylindrical surface, arranged such that a majority of the second coil overlaps a majority of the fourth coil, and including a central terminal in direct electrical contact with the central terminal of the second coil, the fourth coil spiraling in an opposite direction to the second coil.

2. the tubular body, in a deployed configuration, has a generally circular shape with the distal portion generally perpendicular to the longitudinal axis; the tubular body is movable from the delivery configuration to the deployed configuration via manipulation of the proximal shaft; The catheter of claim 1 , wherein the first inductive sensor, the second inductive sensor, and the third inductive sensor are each spaced approximately equidistant from one another around the generally circular shape.

3. The catheter of claim 2 , wherein the generally circular shape includes a circumference measuring approximately 50 millimeters.

4. a support member extending through the tubular lumen of the tubular body within the distal portion; The catheter of claim 2 , wherein the tubular body comprises a flexible polymeric material.

5. a contraction wire extending through the tubular lumen of the tubular body within the distal portion, the contraction wire being movable to change the shape of the distal portion to the generally circular shape; The catheter of claim 4 , wherein the support member comprises a shape memory material and a predetermined shape that approximates the generally circular shape.

6. The catheter of claim 1 , wherein the first inductive sensor, the second inductive sensor, and the third inductive sensor each do not include any inductive coil surrounding the cylindrical surface.

7. the first coil spirals in an opposite direction to the second coil; The catheter of claim 1 , wherein the third coil spirals in an opposite direction to the fourth coil.

8. The catheter of claim 1 , wherein the third coil and the fourth coil are constrained between two electrically insulating, substantially parallel arcuate surfaces.

9. a first conductive trace in direct electrical contact with the first coil and extending from the first coil to the proximal shaft; a second conductive trace in direct electrical contact with the second coil and extending from the second coil to the proximal shaft; a third conductive trace in direct electrical contact with the third coil, extending from the third coil to the proximal shaft and positioned such that a majority of the first conductive trace overlaps a majority of the third conductive trace; 10. The catheter of claim 1, further comprising: a fourth conductive wire in direct electrical contact with the fourth coil, extending from the fourth coil to the proximal shaft, positioned such that a majority of the second conductive wire overlaps a majority of the fourth conductive wire, and electrically connected to the third conductive wire proximal to the proximal shaft.

10. The circuit an insulating substrate fixed to the cylindrical surface; a lower layer above the insulating substrate, the lower layer comprising the third coil, the third conductive trace, the fourth coil, and the fourth conductive trace; an insulating interlayer above the lower layer with vias therethrough, the vias facilitating direct electrical contact between the central terminal of the first coil and the central terminal of the third coil, and between the central terminal of the second coil and the central terminal of the fourth coil; an upper layer above the insulating intermediate layer comprising the first coil, the first conductive trace, the second coil, and the second conductive trace; and an insulating top layer above the top layer.

11. a first contact pad disposed within the upper layer adjacent the proximal shaft; a first wire soldered to the first contact pad and extending through the proximal shaft to the proximal end of the tubular body; a second contact pad disposed within the upper layer adjacent the proximal shaft; The catheter of claim 10, further comprising: a second wire soldered to the second contact pad and extending through the proximal shaft to the proximal end of the tubular body.

12. 2. The catheter of claim 1, wherein the first induction coil, the second induction coil, and the third induction coil each spiral around a corresponding coil axis such that the corresponding coil axis is approximately perpendicular to the cylindrical surface.

13. 13. The catheter of claim 12, wherein each of the first induction coils includes a height measured in the direction of the corresponding coil axis of the first induction coil and a width measured perpendicular to the corresponding coil axis, the width being at least 10 times greater than the height.

14. 1. A method comprising: making a multi-layer flexible circuit comprising a first coil arrangement, a second coil arrangement, and a third coil arrangement; the first coil array, the second coil array, and the third coil array are linearly aligned to define a longitudinal axis of the multi-layer flexible circuit; so that each of the first coil arrangement, the second coil arrangement, and the third coil arrangement comprises four coils; the four coils include a first coil, a second coil, a third coil, and a fourth coil; the first coil including a central terminal and adapted to fit onto a first side of a cylindrical surface; the second coil includes a central terminal and is adapted to fit on a second side of the cylindrical surface approximately 180° around the cylindrical surface from the first side; the third coil is fitted to the first side of the cylindrical surface, is positioned to overlap a majority of the first coil, includes a central terminal in direct electrical contact with the central terminal of the first coil, and spirals in an opposite direction to the first coil; fabricating the fourth coil so that it fits onto the second side of the cylindrical surface, is positioned to overlap a majority of the second coil, includes a central terminal in direct electrical contact with the central terminal of the second coil, and spirals in an opposite direction to the second coil; and securing the multi-layer flexible circuit to the cylindrical surface of the tubular catheter body such that the longitudinal axis of the multi-layer flexible circuit is longitudinally aligned with the tubular catheter body and such that the flexible circuit has a corresponding arcuate cross-section perpendicular to the longitudinal axis through each of the first coil array, the second coil array, and the third coil array.

15. forming a distal portion of the tubular catheter body with a circular shape; 15. The method of claim 14, further comprising: securing the multi-layer flexible circuit to the cylindrical surface such that when the distal portion is in the circular shape, the first coil array, the second coil array, and the third coil array are each spaced approximately equidistant from one another around the generally circular shape.

16. 15. The method of claim 14, further comprising securing the multi-layer flexible circuit to the cylindrical surface such that the first coil arrangement, the second coil arrangement, and the third coil arrangement each do not include any inductive coils surrounding the cylindrical surface.

17. 15. The method of claim 14, further comprising securing the multi-layer flexible circuit to the cylindrical surface such that the first coil arrangement comprises a first induction coil that spirals substantially parallel to the cylindrical surface so that the first induction coil conforms to the cylindrical surface, the second coil arrangement comprises a second induction coil that spirals substantially parallel to the cylindrical surface so that the second induction coil conforms to the cylindrical surface, and the third coil arrangement comprises a third induction coil that spirals substantially parallel to the cylindrical surface so that the third induction coil conforms to the cylindrical surface.

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