Magnetic field sensor

Abstract

To provide a magnetic field sensor.SOLUTION: A magnetic field sensor and a method for 3D-printing of the magnetic field sensor are provided. The magnetic field sensor includes a monolithic body having a plurality of coils 3D-printed inside by continuous printing of a layer along a printing direction. The coils include: a coil (or coils) where a magnetic axis (or axes) is oriented in a longitudinal direction parallel to the printing direction and a coil (or coils) where a magnetic axis (or axes) is oriented in a lateral direction vertical to the printing direction. On the respective coil (or coils) oriented in the lateral direction, magnetic channels bent between a pair of magnetic flux collection surfaces facing each other vertical to the magnetic axis are 3D-printed so that they include a magnetic core section extending along the printing direction. Each of the coils oriented in the longitudinal direction and the coils oriented in the lateral direction are 3D-printed by arranging each conductive winding including a plurality of turns 3D-printed on a flat surface of a 3D-printed layer. Turns of the coils oriented in the lateral direction encircle the magnetic core section up to its magnetic channels.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 533,258, filed Aug. 17, 2023, the disclosure of which is incorporated by reference in its entirety as if set forth herein.

[0002] FIELD OF THEINVENTION The present invention is in the field of magnetic field sensors, and in particular, relates to techniques for fabricating magnetic field sensors suitable for magnetic field based position sensing, especially for sensing the position of medical devices. [Background technology]

[0003] In various therapeutic and diagnostic procedures, catheters / probes are inserted into a patient's body (e.g., a cardiac chamber) where they are brought into contact with bodily tissue. Typically, in such procedures, it is necessary to determine the position of the catheter within the body (i.e., the position where the distal tip of the catheter engages bodily tissue) and the pressure thereby applied to the tissue.

[0004] Catheters having integrated position and pressure sensors for sensing the position of the catheter and the pressure / force applied thereby to the tissue contact area are commonly known. Such catheters typically utilize an inductive coil to determine the position of the catheter within the body and / or the pressure / force applied thereby to the body tissue with which the catheter engages.

[0005] Conventional techniques for such catheters often utilize a wire-wound coil into which a ferrite core may be manually inserted after winding. The coil thus fabricated is then soldered to a cable that carries the coil signal to processing circuitry and mounted within the body of the catheter. [Brief description of the drawings]

[0006] In order to better understand the subject matter disclosed herein, and to illustrate how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: [Figure 1A] A diagram showing a monolithic magnetic field sensor 100 having multiple coils 120, including a longitudinally oriented coil 120L and a transversely oriented coil 120T, 3D printed therein, in accordance with one embodiment of the present invention. [Figure 1B] A diagram showing a longitudinally oriented coil 120L that may be included / 3D printed in the monolithic magnetic field sensor 100 of FIG. 1 according to some embodiments of the present invention. [Figure 1C] A diagram showing a transversely oriented coil 120T that may be included / 3D printed in the monolithic magnetic field sensor 100 of FIG. 1 according to some embodiments of the present invention. [Figure 1D] 1C and 1D show the magnetic channels of the printed coils #D shown in FIG. [Figure 1E] 1C and 1D show the magnetic channels of the printed coils #D shown in FIG. [Figure 2A] A diagram of a transversely oriented coil 120T having a spirally curved / folded magnetic channel that can be 3D printed / included in a monolithic magnetic field sensor / positioning sensor 100 according to some embodiments of the present invention. [Figure 2B] A diagram of a transversely oriented coil 120T having a spirally curved / folded magnetic channel that can be 3D printed / included in a monolithic magnetic field sensor / positioning sensor 100 according to some embodiments of the present invention. [Figure 2C] A diagram of a transversely oriented coil 120T having a spirally curved / folded magnetic channel that can be 3D printed / included in a monolithic magnetic field sensor / positioning sensor 100 according to some embodiments of the present invention. [Figure 2D]A diagram of a transversely oriented coil 120T having a spirally curved / folded magnetic channel that can be 3D printed / included in a monolithic magnetic field sensor / positioning sensor 100 according to some embodiments of the present invention. [Figure 3A] A diagram of a transversely oriented coil 120T having a magnetic channel 129T with a multiple helix shape (double helix in this example) that can be 3D printed / included in a monolithic magnetic field sensor / positioning sensor 100 according to some embodiments of the present invention. [Figure 3B] A diagram of a transversely oriented coil 120T having a magnetic channel 129T with a multiple helix shape (double helix in this example) that can be 3D printed / included in a monolithic magnetic field sensor / positioning sensor 100 according to some embodiments of the present invention. [Figure 3C] A diagram of a transversely oriented coil 120T having a magnetic channel 129T with a multiple helix shape (double helix in this example) that can be 3D printed / included in a monolithic magnetic field sensor / positioning sensor 100 according to some embodiments of the present invention. [Figure 4A] A diagram showing a transversely oriented coil 120T having a magnetic channel curved / folded in a serpentine shape that can be 3D printed / included in a monolithic magnetic field sensor / positioning sensor 100 according to some embodiments of the present invention. [Figure 4B] FIG. 4B is a cross-sectional view of the coil of FIG. 4A. [Figure 5A] A diagram of a longitudinally oriented coil 120L having a magnetic channel curved / folded into a coil shape wrapped around a conductive winding, which may be 3D printed / included in a monolithic magnetic field sensor / positioning sensor 100 according to some embodiments of the present invention. [Figure 5B] A diagram of a longitudinally oriented coil 120L having a magnetic channel curved / folded into a coil shape wrapped around a conductive winding, which may be 3D printed / included in a monolithic magnetic field sensor / positioning sensor 100 according to some embodiments of the present invention. [Figure 6A] FIG. 1 is a side view of a medical instrument 1000 equipped with a monolithic five-axis magnetic field-based position sensor 100, according to an embodiment of the present invention. [Figure 6B] 1 is a perspective view illustrating an internal structure of a magnetic field sensor 100 mounted on a medical instrument 1000. FIG. [Figure 6C] 1 is a perspective view illustrating a configuration of magnetic flux collectors of a magnetic field sensor 100 mounted on a medical device 1000 according to some embodiments of the present invention. [Figure 6D] 1 is a perspective view illustrating the arrangement of electrical contacts / terminals of the longitudinally and transversely oriented coils of the magnetic field sensor 100 disposed on the outer surface of the magnetic field sensor 100. FIG. [Figure 6E] 3D and 3C are diagrams showing the back and front views, respectively, of a signal connector configured to connect / couple with the electrical contacts / terminals of the magnetic field sensor 100 illustrated in FIG. 3D. [Figure 6F] 3D and 3C are diagrams showing the back and front views, respectively, of a signal connector configured to connect / couple with the electrical contacts / terminals of the magnetic field sensor 100 illustrated in FIG. 3D. [Figure 7] FIG. 2 is a flow diagram of a method 200 for fabricating a magnetic field sensor / positioning sensor 100 by 3D printing techniques, according to some embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] There is a need in the catheter art for a physically agile and sensitive catheter having compact / narrow dimensions that can provide accurate feedback regarding the position of the catheter within the body, the contact interface between the catheter and tissue, and the forces (e.g., vectors) applied between them.

[0008] U.S. Patent No. 8,535,308 and U.S. Patent Application No. 2020 / 015693, both of which are assigned to the assignee of the present application, disclose such catheter configurations that utilize sensing circuits having several coils to sense, for example, the position and orientation of the catheter body and the force applied thereby to the interface with tissue.

[0009] One challenge in such catheter technology is fitting accurate position and force sensors within the narrow body of the catheter, whose lateral dimensions are typically only a few millimeters. Indeed, as previously mentioned, in conventional catheter technology, position and force sensors generally utilize micro-wire-wound coils into which ferrite cores can be manually inserted in an open magnetic circuit configuration to generate sufficient induced voltage suitable for position and force sensing of catheter components. However, these conventional techniques are time consuming, expensive, and involve delicate manual manipulation to fit the coils within the small dimensions of the catheter body.

[0010] Thus, there is a need in the art for more efficient and cost-effective techniques for the fabrication of such catheters, as well as for fabrication of small, highly sensitive coils (i.e., having a high induced voltage in response to a magnetic field) suitable for use in catheter position and force sensing as disclosed above. Additionally, there is a need in the art for automated fabrication techniques for such coils suitable for mass production resulting in standardized coils with low variability between coils fabricated with the same design. Additionally, there is a need in the art for further emergence in the art of catheters to facilitate even smaller and / or higher impedance / induced voltages, improve either or both of the sensitivity and agility of the catheters, and / or facilitate reduced dimensions of the catheters.

[0011] The present invention provides a novel positioning sensing system and novel construction and fabrication methods for a magnetic field sensor including an open magnetic circuit coil(s) suitable for a high induced voltage magnetic sensor, for use, for example, as a position sensor fitted within the narrow dimensions of a catheter body.

[0012] 1A-1E are diagrams illustrating a magnetic field sensor 100 (e.g., a multi-axis magnetic field based positioning sensor) according to one embodiment of the present invention. The magnetic field sensor 100 includes a monolithic body 110 having multiple coils 120 defined / fabricated therein by 3D printing of multiple materials in successive printed layers along a printing direction Z.

[0013] In accordance with the present technology, the magnetic field sensor 100 is fabricated by 3D printing of at least three different 3D printable materials M1-M3. These 3D printable materials M1-M3 are: at least one type of magnetic material M1 used / 3D printed to form the magnetic channel(s) 129 of the coil 120, typically including the magnetic core 122 of the coil 120 and also typically its magnetic flux collector 126, as described below; at least one type of conductive (generally non-magnetic) material M2 used / 3D printed to form the conductive channels 128 of the coil 120, including the conductive windings 124 and their contact terminals 123; - at least one type of non-magnetic material, typically a dielectric / non-electrically conductive material M3, that is used / 3D printed to form the bulk of the monolithic body 110 of the sensor 100 in areas where the magnetic and conductive materials are excluded.

[0014] The spaces between adjacent windings / turns 124 are occupied by 3D printed non-electrically conductive material, which may be, for example, a non-magnetic dielectric material M3 3D printed within the bulk of the monolithic body 110 and / or a magnetic material M1 used to print the magnetic channels if it is non-electrically conductive.

[0015] According to some aspects of the invention, the sensor 100 is fabricated utilizing a 3D printing method (additive manufacturing technique) as described in more detail with reference to FIG. 7 below. The 3D printing method involves layer-by-layer deposition of at least three printable materials M1-M3 along a printing direction Z. Typically, the at least three types of printable materials include magnetic material(s) M1 used to print the magnetic channels 129 of the coil 120 (including the magnetic core 122 and its magnetic flux collectors 126), conductive material(s) M2 for printing the electrical channels 128 of the coil (including the conductive windings 124 and electrical contacts 123), and a non-magnetic electrically insulating (dielectric) material that is 3D printed to form the bulk of the monolithic body 110 of the sensor 100 and typically / optionally fills the spaces between the coil's windings 124 to provide electrical insulation therebetween.

[0016] The term magnetic material and / or magnetic particles is used herein to refer to magnetic materials having high relative magnetic permeability μ r For example, a material with a vacuum permeability of μ r ≧100, more preferably, in some cases μ r ≧500 or more μ r It is used herein to indicate a material having a relative magnetic permeability on the order of ≧5000. Conversely, the terms non-magnetic material and / or non-magnetic particles are used herein to indicate a material having a relative magnetic permeability substantially lower than that of the magnetic materials used in the fabrication of electronic components, typically less than μ r Low relative permeability μ is about 1. r Used to indicate the material.

[0017] 1A-6B show various 3D printed aspects / components of the magnetic field sensor 100, with respective legends indicating the color / shade code used in each figure to indicate the different 3D printable materials M1-M3 used to print each aspect / component. In this regard, it should be noted that in some figures (e.g., FIGS. 1B-5B and 6B), the bulk material M3 of the monolithic body 110 is not specifically shown so as not to obscure the figures. Also, in some figures, the same material, such as a magnetic material, is marked with two different color / shade codes to highlight / distinguish between different functional parts / compartments made of the same material.

[0018] 1A-1E, the multiple coils 120 include one or more longitudinally oriented coils 120L and one or more transversely oriented coils 120T. The terms longitudinally oriented coils and transversely oriented coils are used herein to refer to coils whose respective magnetic axes are oriented substantially parallel to and transverse to the print direction Z.

[0019] Each of the coils 120 includes at least one electrical channel 128 3D printed in the monolithic body 110 with the conductive material M2. The electrical channel 128 is 3D printed to include a pair of electrical contacts 123 at opposite ends of the electrical channel 128 and an arrangement of a conductive winding 124 electrically connected between the pair of electrical contacts 123 and including multiple conductive turns of the coil. The electrical channel 128 is thus configured and operable to convert a magnetic flux passing through the winding 124 of the coil (along the coil's respective magnetic axis) into an induced voltage at its electrical contacts 123. The electrical channel 128 is typically configured such that the electrical contacts 123 are disposed from one side of the monolithic body 110, such that electrical connections to the electrical contacts 123 can be efficiently made, for example, by one electrical connector and / or can facilitate mounting of electrical components in tight spaces without the need to access different sides thereof with electrical / signal connecting wires.

[0020] Each of the transversely oriented coils 120T, and typically also each of the (optionally) longitudinally oriented coils 120L, typically has a relative permeability μ r The monolithic body 110 includes at least one magnetic channel 129 3D printed in the monolithic body 110 with a magnetic material M1 having a

[0021] The magnetic channels 129 are 3D printed to include a respective magnetic core 122 surrounded by the conductive windings 124 of the respective coil's electrical channel 128. The magnetic channels 129 are thus configured and operable to direct / guide, and optionally concentrate, an external magnetic flux directed along the respective magnetic axis of the coils to flow / pass through the coil's windings 124 to enhance / increase the induced voltage at the coil's electrical contacts 123 and thus their sensitivity. Also, each magnetic channel 129 of the transversely oriented coils 120T includes a magnetic flux collector 126T coupled from both ends of the magnetic channel 128 and having relatively large magnetic flux collecting faces / surfaces 126F and 126B facing the magnetic axis (e.g., T1 and / or T2) of the respective transversely oriented coil 120T. In longitudinally oriented coils 120L having magnetic channels 129, the magnetic channels 129 are also typically magnetic flux collectors 126L coupled from both ends of the magnetic core 122 and having relatively large magnetic flux collecting faces / surfaces 126U and 126D facing the longitudinal magnetic axes (e.g., L1, L2, and / or L3) of the respective coils. Figures 1D and 1E illustrate and illustrate the magnetic channels 129L and 129T of the longitudinally and transversely oriented coils, respectively. For clarity, the magnetic channels 129L and 129T are shown surrounded by outlines representing the conductive windings 124L and 124T of the longitudinally and transversely oriented coils, respectively.

[0022] 1B and 1C are diagrams illustrating examples of longitudinally oriented coils 120L and transversely oriented coils 120L, respectively, fabricated within the monolithic body 110 of the sensor 100. FIG. 1B illustrates a longitudinally oriented coil 120L including a magnetic channel 129L defining a magnetic core of the coil 122L formed / 3D printed with magnetic material M1, and an electrical channel 128L including a conductive winding 124L having multiple conductive turns surrounding the magnetic core 122L of the coil 120L. FIG. 1C illustrates a transversely oriented coil 120T including a magnetic channel 129T defining a magnetic core of the coil 122T formed / 3D printed with magnetic material M1, and an electrical channel 128T including a conductive winding 124T having multiple conductive turns surrounding the magnetic core 122T of the coil 120T.

[0023] It should be noted that the magnetic channel 129 of any one or more of the coils 120 does not necessarily define a single magnetic path (e.g., passing between the pair of magnetic flux collectors 126 of the coil), but rather in some embodiments the magnetic channel 129 may be divided in the form of multiple magnetic sub-channels that define multiple magnetic cores for a respective coil, each magnetic sub-channel being surrounded by its conductive winding 124. Similarly, it should be noted that the electrical channel 128 of any one or more of the coils 120 does not necessarily define a single conductive path between the pair of electrical contacts 123 of the coil, but rather in some embodiments the electrical channel 128 may be divided in the form of multiple electrical sub-channels that define multiple winding sets that surround the same or different sections of the magnetic core 122 of the coil.

[0024] In some embodiments, the 3D printing technique used to fabricate the sensor 100 provides a printed layer with a thickness substantially smaller than the minimum feature size that can be printed within the layer (in other words, the layer resolution is substantially higher than the resolution of the features / pixels that can be 3D printed, or the layer pitch is greater than the minimum pitch of the features / pixels). For example, in a specific, non-limiting example, the sensor 100 may be printed with a 3D printing technique that provides a transverse intra-layer minimum feature size with a much smaller thickness of printed layers sintered, approximately 9-10 μm, sintered 24-50 micrometers (μm) along each of the lateral X- and Y-axes. Note that here, the minimum intra-layer feature size was considered to be twice the lateral size of the pixels, which have a pitch of approximately 12-25 μm. This is because, in practice, in some / some embodiments, the functional features of the sensor (e.g., conductive turns and / or electrically insulating material between them) are printed at least two pixels lateral in width such that the printing is reliable and robust against intra-layer pixel misprints. In such embodiments, printing the conductive turns planarly within the printed layer facilitates achieving about / more than three times the number / density of turns compared to turns achievable by printing the turns perpendicular / across the printed layer.

[0025] Furthermore, in some embodiments, the magnetic field sensor 100 is fabricated in an elongated shape of the monolithic body 110 such that its length H along the longitudinal axis / printing direction Z is substantially larger than its characteristic lateral width W (e.g., aspect ratio H / W>>1) to facilitate mounting of the sensor 100 in a thin catheter, as shown, for example, in FIG. 6A. For example, in some embodiments, the characteristic lateral width W of the sensor 100 is about 2 mm and its length H is about 4 mm. In such an embodiment, the magnetic channel 129 of the transversely oriented coil(s) 120T is curved to extend along the printing direction Z, and a stack of conductive turns of the coil winding 124T stacked along the printing direction Z is printed, so that each conductive turn is 3D printed planarly in the printing layer to surround the magnetic channel 129, facilitating fabrication of more conductive turns and therefore better sensitivity of the transversely oriented coil(s) 120T.

[0026] Indeed, for a longitudinally oriented coil, such as 120L shown in FIG. 1B, whose magnetic axis L (e.g., L1, L2, and L3 in this example) is parallel to the printing direction and is designed to sense magnetic flux propagating along the printing direction Z, it may be relatively easy to print the conductive turns of the coil's winding 124L planarly in the printed layer, since the turns of the conductive winding 124L are planarly oriented in the printed layer, and they essentially lie in a plane that is substantially perpendicular to the magnetic flux axis L of the longitudinally oriented coil 120L (with the magnetic axis L being parallel to the printing direction Z).

[0027] However, simply printing the turns of the conductive winding 124T of the transversely oriented coil 120T in a planar orientation on a print layer is not sufficient to facilitate sensing of magnetic flux propagating along the magnetic axis T of the transversely oriented coil 120T because the magnetic axis T of a transversely oriented coil, such as 120T shown in FIG. 1C, is oriented transversely (e.g., perpendicular) to the printing direction Z, and in order to capture this magnetic flux, the turns of the conductive winding 124T traditionally must be oriented perpendicular to the magnetic axis T.

[0028] Therefore, to overcome this drawback and obtain more turns / density, and to facilitate printing the turns of the conductive windings 124T of the transversely oriented coils 120T in a planar orientation on the printing layer, each transversely oriented coil 120T is 3D printed within a monolithic body 110 having a magnetic channel 122T including at least a pair of opposing magnetic flux collectors 126T defining / having respective relatively large faces / surfaces 126F and 126B facing the magnetic axis T of the transversely oriented coil 120T (e.g., substantially perpendicular to the magnetic axis T), such that the magnetic channel 129T is curved / folded 127 such that one or more sections 122T that function as the magnetic core of the transversely oriented coil 120T extend along a direction perpendicular / intersecting the magnetic axis T of the transversely oriented coil 120T. Thus, the magnetic channel 129T is curved / folded 127 such that the magnetic core 122T extends substantially perpendicular (e.g., transverse) to its magnetic axis T, such that magnetic flux from the direction of the transverse magnetic axis T of the coil can be collected by the magnetic flux collector 126T and directed through the magnetic core 122T extending perpendicular to the magnetic axis T. The turns (at least some of them) of the conductive winding 124T of the transversely oriented coil 120T are then printed in a planar orientation in the print layer such that they surround the magnetic core 122T and can capture / sense magnetic flux directed therethrough from the direction of the transversely oriented magnetic axis T of the transversely oriented coil 120T. In other words, the magnetic channel 129 is configured and operable to collect, via the faces 126F and 126B of the magnetic flux collector 126T, the magnetic flux of a magnetic field directed substantially along the magnetic axis T of the transversely oriented coil 120T and direct that magnetic flux to flow through the magnetic core 122T, which extends substantially perpendicular to (or, more generally, transverse to) the magnetic axis T. In other words, the core geometry reverses the magnetic field propagating inside the magnetic core 122T by 90° relative to the external magnetic field.

[0029] In this manner, the techniques of the present invention facilitate 3D printing the turns of the conductive windings 124 of both longitudinally and transversely oriented coils 120L and 120T planarly in the plane of the printing layer (i.e., in a plane substantially perpendicular to the printing direction Z), thus resulting in more turns and improved sensitivity of the coil 120 / sensor 100.

[0030] In this regard, it is noted that according to some embodiments, the magnetic flux collector 126T, specifically its faces / surfaces 126F and 126B, facing the magnetic axis T of the transversely oriented coil 120T, are typically made wider (e.g., with a substantially larger area) than the characteristic width (e.g., cross-sectional area) of the magnetic channel 122T between them. Even more specifically, the area of ​​the faces / surfaces 126F and 126B of the magnetic flux collectors is typically made substantially larger than the characteristic cross-sectional area of ​​the magnetic core section(s) 122T of the magnetic channel 129 extending perpendicular to the magnetic axis T, so that the magnetic flux collector 126T collects much more magnetic field flux from the direction of the magnetic axis T than the amount of magnetic flux collected in the magnetic channel from other directions, and thus the transversely oriented coil 120T is negligibly sensitive to magnetic field components parallel to the magnetic axis T, while being highly sensitive to magnetic field components oriented along the magnetic axis T. Optionally, the magnetic flux collector 126T and / or other sections of the magnetic channel are tapered toward the magnetic core section 122T (e.g., to facilitate efficient channeling of magnetic flux from its relatively wide magnetic flux collecting faces / surfaces 126F and 126B into the narrow magnetic channel 122T).

[0031] 1A-1E illustrate one optional configuration of a transversely oriented coil 120T printed on the magnetic sensor 100. The magnetic channel 129T of the transversely oriented coil 120T is curved / folded 127 with one section extending substantially along the printing direction to function as the magnetic core 122T of the coil, and is surrounded by conductive turns 124T that are each printed planarly in the printed layer (e.g., the turns are substantially perpendicular to the printing direction). FIGS. 2A-4B provide depictions of some other non-limiting examples of configurations of the transversely oriented coil 120T, with the magnetic channel 122T curved / folded with several sections 122T extending substantially along (e.g., substantially parallel to) the printing direction, and surrounded by conductive turns 124T to function as the magnetic core 122T. Similar reference numbers are used in Figures 2A-4B to indicate elements / sections of similar function as the transversely oriented coils described above with reference to Figures 1A-1E.

[0032] 2A-2D are diagrams illustrating perspective, side, front, and rear views, respectively, of a transversely oriented coil 120T that may be printed in a magnetic sensor 100, according to an embodiment of the present invention. In this example, the magnetic channel 129T is curved / folded 127 several times between magnetic flux collectors 126T such that the magnetic channel 129T extends substantially along the printing direction Z and is printed / has a spiral shape with multiple sections 122T that function as the magnetic core of the coil. The multiple sections that function as the magnetic core 122T are surrounded by turns of a conductive winding 124T of the conductive channel, the conductive winding being printed planarly on the print layer with a relatively small pitch / distance between the turns. The turns of the conductive winding 124T of the conductive channel 128 are typically spaced apart from one another by an electrically insulating material printed in a layer between the turns (e.g., the electrically insulating material between the turns may be bulk material M3 and / or optionally magnetic material M1 in some locations if it is electrically insulating and does not magnetically short the magnetic flux propagation along the magnetic core). As shown, the magnetic channel 129T is formed in a spiral shape such that the multiple magnetic core sections 122T traverse the conductive winding 124T to direct the magnetic flux flowing between the magnetic flux collectors several times through the conductive winding 124T, thereby improving the sensitivity of the coil. In this non-limiting example, the magnetic channel 129T is folded such that two magnetic core sections 122T traverse the winding 124T, however, one skilled in the art will appreciate that the coil 120T may be printed with other configurations of generally helical channels and may be formed with any suitable number of bends / folds 127 to result in any suitable number of magnetic core sections passing through the winding that provide optimized sensitivity for the particular sensing application being used.

[0033] 3A-3C illustrate side and front views, respectively, and in particular, a portion of a transversely oriented magnetic channel 129 of a coil 120T that may be printed in a magnetic sensor 100, according to an embodiment of the present invention. In this example, between the magnetic flux collectors 126T, the magnetic channel 129T is divided into a number of magnetic sub-channels (two in this example, 129A and 129B), each of which is curved / folded 127 several times in a helical (or otherwise helical) form, so that the magnetic channel 129T has a multiple helical shape (a double helix in this example, one helix formed by each of the magnetic sub-channels 129A and 129B). The magnetic is printed with the curves / folds 127 such that its multiple sections 122T extend substantially along the printing direction Z to function as the magnetic core sections 122T of the coil 120T and are surrounded by the turns of the conductive winding 124T of the coil 120T. In this non-limiting example, the conductive winding 124T includes several winding sets 128A-128D, each including multiple conductive turns surrounding a different one or more of the magnetic core sections 122T. To this end, in various embodiments, the electrical channel 128 between the electrical contacts (shown as 123 in FIGS. 1A-1E ) may be printed as a single conductive path passing between a pair of electrical contacts 123 and shaped to form the winding sets 128A-128D along the single conductive path, or the electrical channel 128 between the electrical contacts may be printed to split into several (e.g., four) electrical sub-channels (which may be connected in series with one another, e.g., to maximize induced voltage within the electrical channel 128), with each electrical sub-channel forming multiple windings / turns of one or more of the winding sets 128A-128D.

[0034] As previously mentioned, and with reference to Figures 1A-1E, in certain embodiments of the invention, the magnetic channel 129 has a tapered shape / structure in the region between the flux collecting surface / face of the magnetic flux collector 126 and the magnetic core section 122. The example shown in Figures 3A-3C illustrates such a tapered shape of the magnetic channel 129, where the cross-sectional area / width of the magnetic channel 129 narrows along a direction proceeding from the flux collecting surface / face of the magnetic flux collector 126 towards the core section 122 of the channel. In this non-limiting example, the tapering of the magnetic channel 129 is gradual in several locations, including the tapering of the magnetic flux collector 126 as shown in the tapered region 121A marked in Figure 3A, as well as the tapering of section 121B of the magnetic channel 129 which directs the magnetic flux between the magnetic flux collectors towards the core section 122 as shown in Figure 3C. The tapering improves coupling of the external magnetic flux from the magnetic axis T of the coil collected by the magnetic flux collector 126 to flow through the magnetic channel, thereby improving the sensitivity of the coil. In this non-limiting example, the tapering of the magnetic channel is illustrated for the transversely oriented coil 120T and illustrated in several tapered regions 121A and 121B, but it should be noted that in general, tapering of the magnetic channel towards the core section may alternatively or additionally be implemented for the longitudinally oriented coil 120L of the sensor 100 shown in FIG. 1A.

[0035] 4A and 4B are diagrams illustrating a transversely oriented coil 120T that may be printed in a magnetic sensor 100 according to yet another embodiment of the present invention. FIG. 4A is a perspective view of the transversely oriented coil 120T, and FIG. 4B is a cross-sectional view of the coil taken along the plane CP. In this example, the magnetic channel 129 extends in a serpentine shape / passes between the magnetic flux collectors 126T. The magnetic flux collectors 126T are not visible in FIG. 4B, but the regions 125 of the magnetic channel 129 to which the magnetic flux collectors 126T are coupled are shown in the figure. The magnetic channel 129 is printed with bends / folds 127 such that its multiple sections 122T extend substantially along the printing direction Z to function as the magnetic core sections 122T. Thus, the magnetic core section 122T is surrounded by turns of the conductive winding 124T, which includes multiple conductive turns surrounding one or more of the different magnetic core sections 122T. To this end, in various embodiments, the electrical channel 128 between the electrical contacts (shown as 123 in FIGS. 1A-1E ) may be printed as a single conductive path passing between a pair of electrical contacts 123 and shaped to form winding sets 128A-128D along the single conductive path, or the electrical channel 128 between the electrical contacts may be printed to divide into several (e.g., four) electrical sub-channels (which may be connected to each other, e.g., in series), with each electrical sub-channel forming multiple windings / turns of one or more winding sets 128A-128D.

[0036] 1A-1E, it should be noted that the magnetic channel 122L of the longitudinally oriented coil 120L may be in the form of a rod (e.g., a straight core) oriented along the magnetic axis L of the coil 120L (i.e., along the printing / longitudinal direction Z) as shown in FIG. 1A, FIG. 1B, and FIG. 1D. In this case, printing the magnetic channel 129 and / or the magnetic core 122L of the longitudinally oriented coil 120L with the magnetic material M1 is not strictly necessary, since the planar printed winding turns in the printing layer of the sensor 100 are essentially oriented to sense / capture the magnetic flux propagating along the magnetic axis L of the longitudinally oriented coil 120L (since the printing direction is substantially parallel to the magnetic axis L of the longitudinal coil 120L). Thus, in general, the magnetic channel / core 129 / 122L passing through the winding 124L of the longitudinally oriented coil 120L, when in the form of a straight rod, may generally be printed with a magnetic material M1, such as ceramic or glass-ceramic, and / or a non-magnetic material, or may be left unprinted / blank (e.g., air channel). Nevertheless, typically, to facilitate improved sensitivity of the longitudinally oriented coil 120L (e.g., to collect and direct more magnetic flux through its winding 124L), the magnetic channel 129 of the longitudinally oriented coil 120L, and in particular its core section passing through the winding 124L, is typically printed with a magnetic material M3, similar to that described with reference to the transversely oriented coil 120T. Additionally, optionally, to further improve the sensitivity of the longitudinally oriented coil 120L to magnetic flux from the direction of the magnetic axis L, as shown in Figures 1B and 1D, the magnetic channel 122L is printed in some embodiments with a respective pair of magnetic flux collectors 126L disposed from both ends thereof.The optional pair of magnetic flux collectors 126L are configured with respective relatively wide / large area faces / surfaces 126U and 126D facing (e.g., perpendicular to) the magnetic axis L of the longitudinally oriented coil 120L, e.g., having a width / area substantially larger than the characteristic width / cross-sectional area of ​​the magnetic core section 122L therebetween (e.g., to direct more magnetic flux through the coil, thereby improving its sensitivity). Optionally, the magnetic flux collectors 126L are tapered toward the magnetic channel core section 122L to facilitate efficient magnetic flux channeling between the relatively wide magnetic flux collecting faces / surfaces 126U and 122D and the narrower magnetic core section 126T.

[0037] It should be understood that the shape of the magnetic channel 122L of the longitudinally oriented coil 120L is not necessarily in the form of a straight rod. For example, in some embodiments where the magnetic channel 122L of the longitudinally oriented coil 120L is printed with a magnetic material M3 that can efficiently guide magnetic flux, the magnetic channel 122L may also be 3D printed to follow a curved / folded path within the monolithic body 110 of the sensor 100 to facilitate directing the magnetic flux through more turns of the conductive winding 124L that surrounds it and / or directing the magnetic flux to pass through the turns of the winding multiple times. This may provide a higher sensitivity of the longitudinally oriented coil 120L.

[0038] For example, the magnetic channel 122L of the longitudinally oriented coil 120L may be curved / folded to follow / form a helical or serpentine path / shape similar to those illustrated above for the transversely oriented coil 120T with reference to Figures 2A-4B (e.g., having only magnetic flux collectors whose magnetic flux collecting surfaces are oriented perpendicular to the magnetic axis L of the longitudinally oriented coil and positioned to collect magnetic flux from that direction). Alternatively or additionally, in some implementations, the magnetic channel 129 of the longitudinally oriented coil 124L may be curved / folded to follow / form a coiled path / shape (e.g., wrapped around the conductive winding 120L), for example, as shown in Figures 5A and 5B.

[0039] To this end, Figures 5A and 5B are schematic diagrams illustrating a longitudinally oriented coil 120L 3D printed in a sensor 100 such that the magnetic channel 129 is curved / folded to form a coiled path / shape of a magnetic core 122L wrapped around a conductive winding 124L. In Figures 5A and 5B, similar reference numbers are used to indicate elements / sections / components of similar function to the longitudinally oriented coil described above with reference to Figures 1A-1E.

[0040] FIG. 5A is a perspective view of the coil 120L including the magnetic flux collector 126L, and FIG. 5B is another perspective view of the coil 120L without the magnetic flux collector 126L, so that the internal configuration of the coiled magnetic core 122L and its wrapping around the conductive winding 124L are visible in the figure. For this purpose, the magnetic flux collected by one of the magnetic flux collectors 126L is guided by the magnetic channel 129 to surround the conductive turns of the winding 124T, typically several times. For example, the magnetic flux collected from the upper magnetic flux collecting surface 126U shown in FIG. 5A is guided through the magnetic channel 129 from the region 125 of the magnetic channel 129 (which is the connection between the magnetic flux collector and the coiled magnetic core 122L), follows the coiled sections C1 to C8 in sequence, and then exits the coil through the bottom magnetic flux collecting surface 126D. The direction of magnetic flux flow through coiled core sections C1-C8 of magnetic core 122L is illustrated. To this end, coiled core sections C1-C8 are wound / wound around (e.g., intertwined with) the turns of conductive winding 124T in a manner that induces a voltage / current in conductive winding 124T, and thereby a voltage at electrical contact 123, in response to magnetic flux propagating through coiled core sections C1-C8.

[0041] Note that in this non-limiting example, the conductive winding includes multiple turns 124S stacked along the printing direction Z in multiple printed layers (e.g., with relatively small spacing between them along the printing direction Z) to further improve the sensitivity of the coil, and in at least some of the printed layers, multiple turns 124C are printed concentrically to further improve the sensitivity of the coil.

[0042] To this end, Figures 1A-5B discussed above generally illustrate various non-limiting examples of multi-axis 3D printed magnetic field sensors 100 including at least one coil 120L having a magnetic axis L oriented longitudinally (the direction in which the printed layers are deposited one on top of the other) along the printing direction Z of the sensor, and at least one coil 120T having a magnetic axis T oriented transversely (e.g., perpendicularly) to the printing direction Z of the print.

[0043] Preferably, in both the longitudinally oriented coil(s) 120L and the transversely oriented coil(s) 120T, the turns of the conductive winding 124 are 3D printed within the printed layers to take advantage of a smaller pitch between the printed layers that is smaller than the minimum feature dimension / width within the layer, packing / printing more conductive winding turns within the coil and facilitating high sensitivity of the sensor (i.e., facilitating high induced voltage in response to magnetic field sensing). To achieve this, for a transversely oriented coil 120T, whose magnetic axis T is generally perpendicular / intersecting the printing direction, its magnetic channel 129 is printed with a pair of magnetic flux collectors 126T facing the magnetic axis T to collect magnetic flux propagating from the pair of magnetic flux collectors 126T, and further printed with turn(s) / fold(s) / curve(s) 127 between the pair of magnetic flux collectors 126T, so that its cross section extends along the printing direction Z, passing through the conductive winding 124TL, and acting as its magnetic core 122T, directing magnetic flux therethrough. In non-limiting embodiments specifically illustrated herein, the magnetic channel 129 of the transversely oriented coil(s) 120T is illustrated with an elongated "Z" shape (FIGS. 1A, 1C, and 1E), a spiral shape (FIGS. 2A-3B), and / or a serpentine shape (FIGS. 4A and 4B). Also, those skilled in the art will understand and readily recognize that the transversely oriented coil(s) 120T according to the present invention can be formed with other magnetic channel 129 shapes as well, with suitable adaptations that may be implemented with a core coil shape, for example, as illustrated in Figures 5A and 5B for the longitudinal coil 120T. With respect to the longitudinally oriented coil(s) 120L, their magnetic channels may be formed as a straight rod-like core along the printing direction Z, while passing through the planar / post-printed winding turns 124T of the coil (for example, as in Figures 1A, 1B, and 1D). Nevertheless, in some embodiments, it may be preferred to print the magnetic channels of the longitudinally oriented coil(s) 120L with more complex shapes, such as the coil-like core shapes illustrated in Figures 5A and 5B.In this regard, those skilled in the art will understand and readily appreciate that the longitudinally oriented coil(s) 120L according to the present invention may similarly be formed with other magnetic channel 129 shapes, with suitable adaptations that may be implemented with a serpentine or helical shape of the core, for example, as illustrated in Figures 2A-4B.

[0044] Furthermore, it should be noted that some optional properties of the 3D printed coil, which are only illustrated in some of the embodiments described above, can be easily implemented in other configurations of the magnetic sensor of the present invention without departing from the present invention. For example, as will be appreciated by those skilled in the art, the following optional properties / features can be implemented in various embodiments of the present invention, including but not limited to those illustrated above: - dividing the magnetic channel 129 between magnetic flux collectors to form multiple magnetic sub-channels, as shown in Figures 3A-3C; - dividing the electrical channel to form multiple conductive paths and, optionally, multiple winding sets, as shown in Figures 3A-3C; and - forming a conductive winding having both a stack of turns in multiple layers and forming concentric turns in each layer or at least some of the layers.

[0045] Typically, one or more, or all, of the coils 120 of the sensor 100 are designed in an open magnetic circuit configuration that is suitable for accurate sensing of magnetic fields, and in particular for magnetic field-based position sensing in medical applications / devices such as catheters. In this context, the phrase open magnetic circuit configuration should be understood herein as relating to a coil structure having an open-ended magnetic channel that provides substantially no shielding or shunting of external magnetic fields, allowing the external magnetic fields to pass through the magnetic core of the coil.

[0046] As mentioned above, the 3D printed magnetic field sensor 100 of the present invention described above may be suitable for use as a position and / or force sensor in a medical instrument / device requiring such a sensor, particularly when the coil 120 is printed with an open magnetic circuit configuration. Reference is also made to FIGS. 6A-6C, which illustrate a medical instrument 1000 (e.g., a probe / catheter) fitted with a magnetic field sensor 100 configured and operable in accordance with an embodiment of the present invention as a 5-axis position sensor (3D spatial position, pitch and yaw), in accordance with an embodiment of the present invention. FIG. 6A is a side view of the medical instrument 1000 fitted with a magnetic field (position) sensor 100, and FIGS. 6B and 6C are two perspective views illustrating the internal structure (FIG. 6B) and the configuration of the magnetic flux collectors (FIG. 6C) of the magnetic field sensor 100 constructed / fabricated in accordance with an embodiment of the present invention.

[0047] To this end, and referring to FIG. 6A, a medical instrument 1000 includes a housing H having a longitudinal axis Z within which, in this non-limiting example, a five-axis magnetic field based position sensor 100 is mounted. In this example, the magnetic field based position sensor 100 is mounted such that the longitudinal axis Z of the housing is along the same direction as the print direction of the magnetic field based position sensor 100. In this embodiment, the magnetic field based position sensor 100 is configured to sense magnetic fields along five axes, including three spaced apart longitudinal axes L1-L3 that are parallel to the longitudinal axis Z of the housing, and two transverse axes T1 and T2 that are not parallel to each other and are not parallel to the longitudinal axis Z of the housing.

[0048] The medical device 1000 includes one or more external magnetic field sources MF that generate a reference magnetic field. L and the magnitude and / or phase of the reference magnetic field is related to an external magnetic field source MF L In other words, it provides a frame of reference for determining the position and / or orientation of the medical device 1000 relative to the external magnetic field source MF. L The reference magnetic field generated by the external magnetic field source MF is measured along three axes by the magnetic field-based position sensor 100 of the medical instrument 100. L1, the 3D spatial position and / or orientation of the medical instrument 1000 relative to the external magnetic field source MF can be determined. To accomplish this, in this embodiment, the magnetic field based position sensor 100 includes at least one longitudinally oriented coil 120L.1 and at least two transversely oriented coils 120T.1 and 120T.2 whose respective magnetic axes L1, T1, and T2 are not parallel to one another and span three dimensions. The at least one longitudinally oriented coil 120L.1 and the at least two transversely oriented coils 120T.1 and 120T.2 are typically coupled to an external magnetic field source MF. L The three coils 120L.1, 120T.1, and 120T.2 are printed in an open magnetic circuit configuration to sense with improved sensitivity the magnetic field generated by an external magnetic field source MF. L , which facilitates the measurement of different vector components of the magnetic field generated by an external magnetic field source MF, as will be readily understood by those skilled in the art. L This facilitates determining the position and orientation of the medical device 1000 relative to a frame of reference defined by the magnetic field of the medical device.

[0049] In one embodiment, the housing H of the medical instrument includes a main portion M and a tip portion T coupled together via a banding coupler J, such as a spring or joint, that is configured to facilitate bending the orientation of the tip portion T relative to the main portion M relative to a longitudinal axis Z of the housing H under an applied force F (e.g., a force that may be applied when the tip portion T of the medical instrument is in contact with a patient's body tissue).

[0050] The medical device 1000 includes a magnetic field source MF therein that provides a reference magnetic field that facilitates the measurement of the degree of bending between the tip portion T and the main portion M by the magnetic field-based position sensor 100. O Typically, the degree of bending is indicative of the magnitude and / or direction of a force F applied to the tip T (e.g., applied between the tip and the patient's body tissue). To measure the magnitude and direction of the force F applied to the tissue by the tip T, the medical device 1000 includes magnetic field sources MF disposed therein and on either side of the joint J within the medical device.O (e.g., a magnetic field generating coil with associated power delivery circuitry), and a magnetic field-based positioning sensor 100 (typically an internal magnetic field source MF O is located at the tip T and the magnetic field based positioning sensor 100 is located at the main part M, although the opposite arrangement may also apply). O are configured and positioned within the housing H (e.g., tip T) to generate a magnetic field having flux lines / axes generally along the longitudinal axis Z of the housing H. The magnetic field-based position sensor 100 includes a monolithic body 110 having a plurality of at least three longitudinally oriented coils 120.1, 120.2, and 120.3, such as those illustrated above with reference to Figures 1A-5B above, which are 3D printed within the monolithic body according to the techniques of the present invention, having respective magnetic axes L1-L3 parallel to the longitudinal axis Z of the housing (which is also the print direction of the sensor 100). The three longitudinally oriented coils 120.1, 120.2, and 120.3 are typically coupled to an internal magnetic field source MF O As will be appreciated by those skilled in the art, the magnetic axes L1-L3 of the three longitudinally oriented coils 120.1, 120.2, and 120.3 are collinear / parallel to one another and parallel to the longitudinal axis L of the housing H, and are not co-planar (not coplanar), and therefore the magnetic axes L1-L3 of the three longitudinally oriented coils 120.1, 120.2, and 120.3 of the internal magnetic field source MF O The magnetic field measured from the magnetic field position sensor 100 (e.g., the amplitude measured by each of the coils) is calculated based on the magnetic field position sensor 100 and the internal magnetic field source MF O To this end, given the technology of the present invention, one skilled in the art can easily determine the relative orientation of an internal magnetic field source MF O The orientation of the sensor 100 with respect to the magnetic field source MF produced by three longitudinally oriented coils 120.1, 120.2, and 120.3. OIt will be readily apparent how the force vector F applied to the tissue can be determined based on this measured orientation of the sensor 100 and the properties (e.g., spring constant) of the banding coupler J.

[0051] Thus, in this non-limiting example, the magnetic field sensor 100 is coupled to an external magnetic field source MF L its position and orientation relative to the internal magnetic field source MF O 1 and its orientation relative to the axis of the magnetic field sensor 100. Thus, the magnetic field sensor 100 is configured as a five-axis magnetic field sensor capable of measuring magnetic fields from three aligned longitudinal axes L1-L3 and two transverse axes T1 and T2. However, it should be noted that the present invention is not limited to the five-axis configuration of the magnetic field sensor / positioning sensor 100, but may be used to implement a magnetic field sensor / positioning sensor 100 having two, three, or four sensing axes, and / or any other desired number of sensing axes. For example, - a 3-axis magnetic sensor for measuring the 3D position / orientation of a medical device relative to an external magnetic field (3-axis sensor); - a 2-axis magnetic sensor for measuring the 2D position / orientation of a medical device relative to an external magnetic field; - a two-axis magnetic sensor for measuring one of the orientation angles of the sensor relative to an internal magnetic field (e.g., either pitch or yaw); - a 3 or 4 magnetic axis sensor for measuring one orientation angle of the sensor with respect to an internal magnetic field (e.g., either pitch or yaw) and the 2D or 3D position / orientation of the medical device with respect to an external magnetic field, respectively; and - A 5-axis magnetic sensor as in this embodiment for measuring two orientation angles (eg pitch and yaw) of the sensor relative to the internal magnetic field, as well as the 3D position / orientation of the medical device relative to the external magnetic field.

[0052] In this regard, it should be noted that in light of the description herein, after understanding the present invention, one of ordinary skill in the art will readily understand how to fabricate a magnetic field sensor by 3D printing using any suitable number of coils and various configurations / orientations of their magnetic axes relative to the printing direction Z to facilitate accurate / sensitive measurement of the sensor's position and / or orientation relative to one or more magnetic field sources in one, two, and / or three dimensions.

[0053] 6B and 6C are perspective views showing in more detail the configuration of a five-axis magnetic field sensor 100 according to an embodiment of the present invention, which is incorporated into the medical device 1000 described above. FIG. 6B is a perspective view of the magnetic field sensor 100 showing the internal structure / coils of the five-axis magnetic field sensor 100, whose monolithic body 110 is depicted only by dashed-dotted outline (its printed bulk material M3 is not shown so as not to obscure the configuration of the coil 120 of the 3D printed sensor). FIG. 6C is another perspective view of the five-axis magnetic field sensor 100 showing the arrangement of some of the magnetic flux collectors 126 of the coil of the sensor 100. The magnetic field sensor 100 in this example is fabricated by the 3D printing technique of the present invention described above with reference to Figures 1A-5B and includes three longitudinally oriented coils 120L.1-120L.3 having respective parallel magnetic axes L1-L3 oriented along the longitudinal / printing direction Z, and two transversely oriented coils 120T.1 and 120T.2 having respective non-parallel magnetic axes T1 and T2 oriented in two transverse directions.

[0054] The three longitudinally oriented coils 120L are aligned with each other such that their respective magnetic axes are parallel to each other. This arrangement of the longitudinally oriented coils 120L is aligned with an internal magnetic field source MF located in front of the magnetic field sensor 100 with respect to the longitudinal direction Z. OMF, thereby facilitating the use of the sensed / acquired magnetic signals to determine the two orientation angles of the magnetic field sensor 100 with respect to the external magnetic field source(s) MF. Additionally, since the magnetic axes T1 and T2 of the two transversely oriented coils 120T and at least one magnetic axis, e.g., L1, of the at least one longitudinally oriented coil 120L span 3D coordinates, the sensed / acquired magnetic signals from the two transversely oriented coils 120T and at least one longitudinally oriented coil 120L may be used to determine the two orientation angles of the magnetic field sensor 100 with respect to the external magnetic field source(s) MF. L The magnetic field may be utilized / processed to determine the position (eg, location and / or orientation) of the sensor relative to a reference coordinate frame provided by the magnetic field of the sensor.

[0055] In this example, the magnetic field sensor 100 has an elongated, tubular / cylindrical shape about a longitudinal / printed axis Z with a width / diameter W that is small enough to fit within a housing H of the medical device 1000. For example, the inner diameter of the housing H, and therefore the width / diameter W of the magnetic field sensor 100, may be on the order of about 2 millimeters.

[0056] In some embodiments, to facilitate compact arrangement of the coils 120L.1-120L.3 and 120T.1 and 120T.2 within the narrow monolithic body 110, the three longitudinally oriented coils 120L.1-120L.3 are arranged in three respective angular sectors about the longitudinal / printing axis Z, and the two transversely oriented coils 120T.1 and 120T.2 are arranged in two respective angular sectors about that axis. Preferably, in some embodiments, the three longitudinally oriented coils 120L.1-120L.3 transmit equally "weighted" magnetic field signals to the internal magnetic field source MF. O. are equally spaced (e.g., forming an equilateral triangle) so that the magnetic field is obtained from the three longitudinally oriented coils 120L.1-120L.3. For example, in this non-limiting example, the three longitudinally oriented coils 120L.1-120L.3 are equally spaced from each other by 120°. The transversely oriented coils 120T.1 and 120T.2, e.g., their magnetic axes T1 and T2, are typically angularly spaced from each other and oriented with respect to the longitudinal / printing axis Z by an angle relatively close to 90° (within a range of tens of degrees from 90°) so that the magnetic signals read therefrom can be used / processed to identify / determine the two perpendicular vector components of the magnetic field sensed thereby with a high SNR (e.g., without too much overlap between the vector components of the magnetic fields sensed individually). Also, typically, the relative angular spacing between the transversely oriented coils 120T.1 and 120T.2 is further optimized to facilitate a compact arrangement of the coils 120 of the sensor in a monolithic body, or other features.

[0057] For example, in the embodiment illustrated in FIG. 6B , the transversely oriented coils 120T.1 and 120T.2 and their magnetic axes T1 and T2 are angularly spaced / oriented relative to one another about the longitudinal / printing axis Z by an angle of 120°, thus facilitating compact placement of coils having relatively high sensitivity within the limited maximum dimensions of the sensor 100 for attachment to the medical instrument 100 (with this configuration / size / shape of the coils).

[0058] To this end, in some embodiments, compact sensor dimensions and high quality position signal sensing (e.g., sensing of substantially equally weighted vector components of a desired magnetic field is achieved by an arrangement of the five coils 120L.1-120L.3 and 120T.1 and 120T.2 in five respective angular sectors at the same level / height relative to the Z axis). Alternatively, in some embodiments (not specifically shown in the figures), compact sensor dimensions and high quality position signal sensing are optimally obtained by an arrangement of three longitudinally oriented coils 120L.1-120L.3 in an angular sector at one level / height relative to the longitudinal / printing axis Z and two transversely oriented coils 120T.1 and 120T.2 in two angular sectors at another level / height relative to the longitudinal / printing axis Z.

[0059] As shown in this non-limiting example, the magnetic field sensor 100 has an annular shape and has holes 115 fabricated (not printed) through its monolithic body 115 along the longitudinal axis Z to allow passage of some components of the medical device 100 (catheter electrical / signal lines and / or fluid lines). To this end, such an elongated shape of the sensor 100 severely limits the maximum distance D between a pair of opposing magnetic flux collectors 126T. For example, in a sensor having an annular shape with a width W of about 2 mm, with each of the transversely oriented coils 120T having a magnetic flux collector 126T near the outer surface of the annular shape and a magnetic flux collector 126T located near the inner surface of the annular shape facing the hole 115, as shown in the figure, the maximum distance D between opposing magnetic flux collectors 126T along the magnetic axis T of the transversely oriented coils 120T is substantially limited to less than 1 mm (e.g., typically limited to only about 0.5 mm, considering that the hole 115 typically has a diameter of about 1 mm or less). Thus, at such short distances along the magnetic axis T of the transversely oriented coils, it is not practical with current conventional 3D printing techniques to fabricate transversely oriented coils 120T with straight / rod magnetic cores that provide sufficient sensitivity suitable for positioning medical devices. This problem is overcome by the technique of the present invention by printing the magnetic core of the transversely oriented coil 120T to have an extended length (e.g., greater than the distance between the magnetic flux collectors 126T) to include a magnetic channel 122T between the curved / folded magnetic flux collectors 126T within the monolithic body 110 of the sensor 100, thereby facilitating 3D printing more conductive windings 124T around the magnetic channel 122T (compared to when the rod core is shorted), which then improves the sensitivity of the sensor's transversely oriented coil 120T despite its elongated shape.

[0060] 6D-6F, an embodiment of a sensor 100 is shown that is configured to facilitate robust, reliable, and cost-effective connection of signal wires 159 to the sensor's coils 120 before / during attachment of the sensor's monolithic body 110 to a medical device 1000. In this embodiment, the sensor 100 includes a signal connector 150, as optionally illustrated in FIG. 6A and shown in detail in FIGS. 6E and 6F, and a 3D printed monolithic body 110 with multiple coils 120 (including transversely and longitudinally oriented coils 120T and 120L) 3D printed therein. As shown in FIG. 6D, the electrical contacts / terminals 123 of the coils 120 are exposed from the monolithic body 110 at its surface, which is typically planar. In this example, there are ten electrical contacts / terminals 123, two for each of the five coils 120, arranged in a predetermined arrangement. A signal connector 150, the back and front of which are shown in Figures 6E and 6F, respectively, includes a printed circuit board (PCB) 151 having a complementary arrangement of electrical contact pads 153 from its back (Figure 3E) that matches the arrangement of electrical contacts / terminals 123 in the monolithic body 110. Each of the electrical contact pads 153 on the back (Figure 3E) of the signal connector 150 is electrically coupled to solder contacts 154 on the front of the PCB 151, for example, by conductive vias and / or redistribution lines (RDLs) in the PCB 151. A signal cable 158 including a plurality of conductive signal wires 159, typically shielded signal wires such as twisted pairs, is electrically connected to the solder contacts 154, typically by soldering / wire bonding. More specifically, in this example, there are five twisted pairs (only two are shown in the figure for clarity), each of which is soldered to a respective pair of solder contacts 154 that are electrically coupled (through RDLS / vias) to electrical contact pads 153 located on the back of the signal connector 150 so as to contact a pair of electrical contacts / terminals 123 of one of the coils 120 in the monolithic body 110.

[0061] In some embodiments, the signal connector 150 optionally includes a fastening area 155 on its front side, to which the signal cable 158 can be attached (e.g., affixed) to improve the robustness and reliability of the electrical connection to the solder contacts 154 of the signal connector 150 (e.g., to ensure that it can withstand stress / tension that may be applied during mounting of the sensor 100 within the tight space of the medical device 1000).

[0062] To this end, during installation of the sensor 100 within the medical device 1000, for example before or after the monolithic body 110 is inserted into the device 1000, the signal connector 150 may be attached to the monolithic body 110 such that the electrical contact pads 153 on the back side of the signal connector 150 are electrically coupled to a complementary arrangement of electrical contacts / terminals 123 of one of the coils 120 within the monolithic body 110 (as will be appreciated by those skilled in the art, this may be reliably performed using soldering, for example using flip-chip bonding).

[0063] In some embodiments, for example, as illustrated in Figures 6D-6F, the monolithic body 110 and the signal connector 150 of the sensor 100 include complementary trenches 102 and notches 152, respectively, which are arranged to align when the signal connector 150, properly coupled to the monolithic body 110 having the electrical contact pads 123, properly contacts the respective electrical contacts / terminals 153. Considering the micro-sized size of the sensor 100 in some embodiments, the trenches 102 and notches 152 facilitate accurate and easy alignment between the monolithic body 110 and the signal connector 150 of the sensor 100 when they are attached / coupled to each other such that the electrical contact pads 153 are properly coupled to the respective electrical contacts / terminals 123. Alternatively or additionally, in some embodiments, the trench 102 and notch 152 route signal / power lines through the narrow housing H of the medical device 1000 toward the tip of the medical device 1000 when the sensor 100 is installed within the medical device 1000 (e.g., to allow for contact with an internal magnetic field source MF OThe power supply provides a path for the power source to be connected to the power supply.

[0064] It should be noted that in some implementations of the magnetic field sensor / positioning sensor 100 described with respect to all the above embodiments, the electrically conductive material M2 used for 3D printing the electrical channel 128 of the coil 120 comprises silver. Alternatively or additionally, in some embodiments, the electrically conductive material M2 may comprise copper, silver, palladium, and / or a silver-palladium alloy. The magnetic material M1 used for 3D printing the magnetic channel 129 of the coil 120 (i.e., their magnetic core 122 and magnetic flux collector 126) may generally comprise a ceramic-ferrite material and / or a metallic material. In some embodiments, the magnetic material M1 has a relative permeability μ of at least 100 or more. r Preferably, the magnetic material M1, specifically the magnetic material used to print the magnetic channels 129 of the transversely oriented coil 120T, has a relative permeability μ of the order of 5000 or more. r (In some embodiments, the folded / curved magnetic channel has a relatively small cross section and therefore a relatively high magnetic permeability μ on the order of 5000 or more. r (which is required to control / facilitate focusing of the magnetic field flux with sufficiently small losses). This is to facilitate efficient channeling of the magnetic flux through the folded / curved magnetic channels of the transversely oriented coil 120T. The non-magnetic dielectric material M3 (also referred to herein as bulk material) may include, for example, ceramic and / or glass-ceramic. Preferably, in some embodiments, the conductive material M2 of the conductive channel(s) 128 is printed to be fully embedded within the bulk of the monolithic body 110 and isolated from environmental conditions that may degrade it. Optionally, in some embodiments, the electrical contacts / terminals of the conductive channel(s) are also 3D printed embedded within the bulk and exposed to the outside (e.g., by grinding) only after the 3D printed sensor is sintered / fired.

[0065] As mentioned above, the magnetic field / position sensor 100 of the present invention is fabricated by 3D printing of at least three different 3D printable materials M1-M3 as exemplified in all the above embodiments. Figure 7 is a flow diagram of a method 200 used according to some embodiments of the present invention to fabricate the above-mentioned magnetic field sensor 100 by 3D printing technology.

[0066] In operation 210 of the method 200, a model of one or more magnetic field sensors 100 of the present invention, such as those described above with reference to any one of the embodiments of Figures 1A-6F, to be 3D printed, is provided. The model shows a 3D spatial distribution (voxel map) of at least three materials M1-M3 that are 3D printed to fabricate the magnetic field sensor 100 of the present invention. In particular, the model shows the spatial distribution of each of the three materials M1-M3 that need to be 3D printed to form the magnetic field sensor 100 according to the present invention. More particularly, the spatial distribution of the three materials M1-M3 is such that the 3D printing results in a magnetic field sensor 100 having a monolithic body 110 with one or more longitudinally oriented coils 120L and one or more transversely oriented coils 120T printed within the monolithic body 110.

[0067] Typically, the multi-material 3D printing used works by successive printing of layers, one on top of the other, along the printing direction Z. Each layer may contain one, two or all three materials. The spatial distribution of the three materials M1-M3 in the model used for printing is such that the printing result is a number of coils 120 defined by the distribution of the three materials M1-M3 in the monolithic body 110, the bulk of which is 3D printed with the non-magnetic, non-conductive material M1. The internal number of coils 120 is - one or more longitudinally oriented coils 120L, each including a conductive winding 124L, the magnetic axis (L) of each of which is oriented substantially parallel to the printing direction Z, the conductive winding 124L including an arrangement of conductive turns planarly 3D printed in a plurality of 3D printed layers with a conductive material M2; - one or more transversely oriented coils 120T, each with a magnetic axis (T) oriented substantially transverse / perpendicular to the printing direction Z. Each transversely oriented coil 120T includes a magnetic channel 129 3D printed with magnetic material M1 such that the magnetic channel 129 includes at least a pair of opposing magnetic flux collectors 126T with a respective relatively large face perpendicular to the transversely oriented magnetic axis (T). The magnetic channel 129 of the transversely oriented coil 120T includes one or more bends / folds 127 printed in the monolithic body 110 such that one or more sections 122T of the magnetic channel 129 extend substantially along the printing direction Z to function as the magnetic core of the coil, and the transversely oriented coil 120T includes a conductive winding 124T including an arrangement of conductive turns 3D printed planarly in multiple 3D printed layers with conductive material M2 to surround the magnetic core 122T.

[0068] The spatial distribution of the three materials M1-M3 within the model may further define other features of the sensor 100, as described above. For example, magnetic channels may also be fabricated for longitudinally oriented coils 129, the magnetic channels 129 of longitudinally and / or transversely oriented coils may be formed in various even more complex shapes, for example as described in Figures 2A-5B, the conductive windings of the coils may generally be 3D printed as part of electrical channels 128 that terminate with two or more electrical contacts / terminals 123 at the surface of the monolithic body 110, and the monolithic body 110 may be formed in an elongated / tubular shape and / or a cylindrical and / or annular shape with holes 115 therein, or other geometric shapes of the body for attachment to a particular catheter.

[0069] In operation 220 of the method 200, multi-material 3D printing is applied to print one or more magnetic field sensors 100 based on the spatial distribution of three or more materials M1-M3 in the model. Multi-material 3D printing may be performed, for example, by utilizing photopolymerization 3D printing technology to print layers composed of a combination of several materials with different electromagnetic properties (e.g., two, three, or optionally four or more materials with different electromagnetic properties may be printed in each layer). In a typical example, the 3D printing of the magnetic field sensor 100 described above involves printing a spatial distribution of at least three materials of different electromagnetic properties, including an electrically conductive material M2 for 3D printing the electrical channel 128 of the coil 120, a magnetic material M1 for 3D printing the magnetic channel 129 of the coil 120, and a non-magnetic dielectric material M3 for 3D printing the bulk of the monolithic body 110 of the sensor 100.

[0070] To this end, in various embodiments, the electrically conductive material M2 may comprise, for example, silver and / or copper and / or palladium and / or a silver-palladium alloy. The magnetic material M1 may comprise, for example, a ceramic-ferrite material and / or a metallic material. In some embodiments, the magnetic material M1 has a relative permeability μ of at least 100 or more. r Preferably, the magnetic material M1, and in particular the magnetic material used to print the magnetic channels 129 of the transversely oriented coil 120T, is a material with a relative permeability μr on the order of 5000 or higher to facilitate efficient channeling of magnetic flux through its folds / curves 127. The non-magnetic dielectric material M3 (also referred to herein as the bulk material) may include, for example, ceramics and / or glass-ceramics.

[0071] 3D printing of the sensor 100 may be performed using, for example, stereolithography (SLA) or digital light processing (DLP) for pattern implementation / projection, for example based on the principle of liquid vat photopolymerization. The invention is not limited to these specific techniques and may generally be performed with other multi-material 3D printing techniques that may be developed suitable for the fabrication of electrical components according to the invention.

[0072] Using the techniques of the present invention, magnetic field sensors 100 with small feature dimensions can be printed utilizing 3D printed layers with thicknesses on the scale of down to micrometers (e.g., the sintered layer thickness can be on the order of about 8-10 micrometers), with feature sintered size features on the scale of about 24-50 micrometers or less (this takes into account that intralayer pixels can be printed with a pitch / width of about 12-25 micrometers, and that it is preferable to print each critical / functional feature with a width of at least 2 pixels to avoid malfunctions due to a single pixel misprint).

[0073] To perform 3D printing, at least three curable resins corresponding to materials M1, M2, and M3 are provided. More specifically, the curable resins used in 3D printing of the magnetic field sensor 100 of the present invention include, for example: - a magnetic material resin comprising particles of a magnetic material M1 of a soft magnetic material suspended in a curable polymer binder. The particles of the magnetic material M1 may comprise, for example, particles of a ceramic-ferrite material. It should be noted that, alternatively, in some embodiments, the particles of the magnetic material M1 may comprise particles of a magnetic metallic material such as iron alloys, iron-silicon alloys, iron-aluminum-silicon alloys, low carbon steel, nickel-iron alloys, iron-cobalt alloys, ferrites, amorphous alloys, and possibly nickel-cobalt alloys (particularly if they have soft magnetic properties). In embodiments in which microcoils are fabricated in the monolithic body 110, the particles of the magnetic material used may be provided with characteristic sizes, for example, on the micrometer to sub-micrometer scale, especially if the magnetic channel 129 of the coil presents delicate features. - a conductive material resin comprising particles of conductive material M2 suspended in a curable polymer binder. The particles of conductive material M2 may comprise, for example, a silver material, a copper material, and / or a silver-palladium alloy. The specific selection of a suitable conductive material may generally depend on the required temperature of the sintering / firing process required to complete the printing of the electrical component, and thus on the type of magnetic and dielectric materials. In embodiments in which micro coils are fabricated in the monolithic body 110, the particles of conductive material M2 used for printing may have characteristic sizes as small as micrometer to sub-micrometer and nanometer scales. - a dielectric and non-magnetic material resin comprising particles of a non-magnetic dielectric material M3 suspended in a curable polymer binder. The particles of the non-magnetic dielectric material typically comprise ceramic or glass-ceramic particles capable of withstanding the high sintering / firing temperatures required to sinter the printed magnetic and conductive materials M1 and M2. Also herein, the size of the particles may be selected according to the minimum feature size to be occupied by the dielectric material / bulk of the magnetic field sensor, for example on the nanometer to micrometer scale for the fabrication of a micro coil.

[0074] Regarding the above material selection, it should be noted that although it is generally possible to print the magnetic channel 129 with a magnetic metal material, in various embodiments it may be preferable to print the magnetic channel with an electrically insulating ceramic ferrite. One reason for this is that the use of ceramic ferrite makes it easier to achieve a more compact arrangement of the magnetic channel 129 and the electrical channel 128. This is because soft magnetic metal materials (non-ceramic ferrites) suitable for use in magnetic channel printing are generally conductive. Thus, the magnetic channel 129 printed with non-ceramic ferrite should be spaced apart from the electrical channel 128 at least in some places to prevent short circuits, which may affect the achievable miniaturization of the magnetic field sensor 100 and / or require a more complex design thereof. Thus, in some embodiments, a ceramic ferrite material is preferably used for printing the magnetic channel 129.

[0075] Thus, utilizing the at least three curable resins described above, the 3D printing of the magnetic field sensor 100 may be performed layer by layer along the printing direction Z, for example, using a photopolymerization multi-surface 3D printing technique such as SLA or DLP. The printing direction Z is typically selected to be substantially perpendicular to the plane in which the turns of the conductive winding 124 of the coil 120 extend. To this end, as previously mentioned, the selection of the printing direction Z may be particularly important in the printing of the miniature magnetic field sensor 100, since the lateral feature resolution of the printing in the XY plane is lower than the "vertical" resolution of the layers obtained along the printing direction Z.

[0076] To this end, typically, the 3D printing of each layer of the sensor 100 is performed in a step-by-step manner. - deposition / printing and curing of a magnetic material M1 in the area of ​​the layer corresponding to the magnetic channel 129 of the coil 120; - deposition / printing and curing of a conductive material M2 in the areas of the layer corresponding to the electrical channels 128 of the coil 120, and - Deposition / printing and curing of a non-electrically conductive (dielectric), non-magnetic material M3 (not necessarily in that order) to form the bulk of the monolithic body 110 of the sensor 100.

[0077] It should be noted that in some embodiments, 3D printing is performed such that the conductive material M2 is completely embedded within the bulk of the monolithic body 110 to protect the conductive material M2 from degradation (e.g., oxidation) due to environmental conditions, particularly during the high temperature sintering 230 following layer-by-layer material deposition and curing.

[0078] Thus, successive printing and curing of successive layers in operation 220. results in one or more 3D structures of one or more sensors 100, each including electrical coils 220 of at least one longitudinally oriented coil and at least one transversely oriented coil according to the spatial distribution of material in the model of the sensor.

[0079] The method 200 further includes an operation 230 for sintering one or more 3D structures of the one or more sensors 100 printed in operation 120. Sintering is generally performed at a temperature sufficient to burn or remove the polymer (binding polymer) from the one or more magnetic field sensors 100, and to sinter the ceramic or glass-ceramic materials, such as M3 and optionally M1, used in printing. To this end, after sintering, the material density of the printed ceramic and metal materials (e.g., M1, M2, and M3) of the magnetic field sensor 100 approaches 100%. For example, in an embodiment in which the conductive material M2 mainly comprises silver, sintering may be performed at a temperature below the melting point of silver (e.g., at a temperature not exceeding 961° C., in which case the sintering temperature may be preferably limited to about 900 C to achieve a stable sintering process). In other embodiments in which the conductive material comprises a silver-palladium alloy, sintering may be performed at a temperature below the alloy melting point (the particular melting point depends on the ratio of silver to palladium in the alloy, and depending on the composition, the melting point is generally between the melting point of silver at 961° C. and the melting point of palladium at 1,555° C.). In another example, in embodiments in which the conductive material M2 comprises copper, sintering may be performed in an oxygen-deficient environment (to avoid oxidation of the copper) at a temperature below the copper melting point of 1,084° C.

[0080] In this regard, it is noted that in some embodiments of the present invention, the method 200 is performed for a 3D printed magnetic field sensor / positioning sensor 100 with embedded micro-coils having micrometer-scale feature sizes. For example, the 3D printed layers may be printed with a sintered thickness in the range of about 5-15 μm (e.g., 9 μm), depending on the particular model design and the 3D printing technology used. Thus, the pitch of the turns of the winding 124 may be on the order of twice the pitch of the 3D printed layer, but may be in the range of about 10 μm to 30 μm along the printing direction Z of the 3D printed sintered layer (e.g., typically, the layer thickness is on the order of 9 μm and the pitch of the turns between the phases is about 18 μm).

[0081] Further, optionally (depending on the particular printing technique used), method 200 may include operation 240 for separating the printed sensor 100 from the build / 3D printing platform (e.g., 201 shown in FIG. 1E). In general, depending on the type of build platform (e.g., whether it can withstand sintering 230), operation 240 may be performed before or after sintering 230. Indeed, in some embodiments of the present invention, particularly when small / delicate sensors are printed that may be damaged by performing separation from the build platform before sintering, a suitable build platform that can withstand the temperatures of sintering 230 may be used, and separation of the sensor from the platform may be performed after sintering to avoid / reduce damage to the sensor during the separation process.

[0082] In view of the above, the method 200 of the present invention provides a novel and inventive technique for the fabrication of magnetic field sensors / positioning sensors 100 including multiple coils 120 as described above. The method 100 is suitable for fabrication of micro-sensors 100 having feature sizes as small as a few micrometers and may be used in mass production to simultaneously 3D print many such micro-sensors 100 built simultaneously on the same platform (e.g. typically hundreds to thousands may be printed using, e.g., liquid bath photopolymerization techniques). Each magnetic field sensor / positioning sensor 100 may have, e.g., a ceramic / glass-ceramic body 110 having embedded therein a highly sensitive open magnetic circuit coil arranged in both a transverse and longitudinal orientation relative to the printing direction Z. The micro magnetic field sensors / positioning sensors 100 may be fabricated with dimensions as small as about 2 mm wide and a few millimeters high, e.g., having dimensions as small as about 0.5 mm to about 4 mm, with coils 120 therein providing high sensitivity / induced voltage in response to magnetic fields in the range of about 0.1 to 1 μV / (Gauss*Hz).

[0083] It should be noted that the illustrations of magnetic field sensor / position sensor 100 in Figures 1A-6F are provided for illustrative purposes only and are not necessarily drawn to scale or to scale. For example, in general, the number of windings in coil 120 according to the present invention may be substantially greater than those shown in the figures. Also, the particular shapes shown for coil 120, such as those of windings 124 of magnetic core 122 and flux collector 126, are provided by way of example only and may in fact have shapes and / or aspect ratios other than those shown without departing from the scope of the present invention. EXAMPLES

[0084] Example 1. A magnetic field sensor, a monolithic body having a plurality of coils defined therein by 3D printing of successive printed layers along a printing direction, the plurality of coils comprising: one or more longitudinally oriented coils having respective first magnetic axes oriented substantially parallel to the printing direction, each of the longitudinally oriented coils including a 3D printed first conductive channel forming a first conductive winding arrangement having turns in the plane of the printed layer; a magnetic field sensor, the plurality of coils further including one or more transversely oriented coils having respective second magnetic axes oriented transversely to the print direction.

[0085] Example 2. Each transversely oriented coil of the transversely oriented coils includes: a magnetic channel 3D printed within the monolithic body such that the magnetic channel includes at least a pair of opposing magnetic flux collectors having respective faces perpendicular to a second magnetic axis, and at least one section between the at least one pair of opposing magnetic flux collectors that serves as a magnetic core for the transversely oriented coil; and a 3D printed second conductive channel forming an arrangement of a second conductive winding 3D printed within the monolithic body surrounding the at least one magnetic channel; A magnetic field sensor as described in example 1, wherein the magnetic channel forms a curve in the monolithic body such that at least one section of the magnetic channel functioning as a magnetic core extends along the printing direction and the arrangement of the second conductive winding includes a plurality of turns printed in the plane of the printing layer to surround the at least one section functioning as a magnetic core.

[0086] Example 3. A magnetic field sensor as described in Example 2, wherein the monolithic body has an elongated shape along the printing direction and has a relatively short distance between a pair of opposing magnetic flux collectors, and the curvature of the magnetic channel within the monolithic body facilitates an extended length of at least one section that functions as a magnetic core to accommodate more turns of the second conductive winding around the extended length, thereby improving the sensitivity of the transversely oriented coil despite the short distance between the pair of magnetic flux collectors.

[0087] Example 4. The one or more longitudinally oriented coils include three longitudinally oriented coils of similar magnetic properties, the three longitudinally oriented coils being 3D printed such that they are aligned with one another and their respective first magnetic axes are parallel to one another, thereby enabling signals obtained from the three longitudinally oriented coils to be utilized to determine two orientation angles of the magnetic field sensor relative to a first magnetic field source located in front of the magnetic field sensor along the general direction of the first magnetic axes; A magnetic field sensor as described in any one of Examples 1 to 3, wherein the one or more transversely oriented coils include two transversely oriented coils that are 3D printed such that their respective two transversely oriented magnetic axes are not parallel to each other and that the two transversely oriented magnetic axes span 3D coordinates with the longitudinally oriented magnetic axis of at least one of the longitudinally oriented coils among the one or more longitudinally oriented coils, thereby enabling signals obtained from the two transversely oriented coils and the at least one longitudinally oriented coil to be utilized to determine the position and orientation of the sensor relative to one or more second magnetic field sources.

[0088] Example 5. A magnetic field sensor as described in Example 4, wherein at least three longitudinally oriented coils are arranged within three respective angular sectors about the longitudinal axis of the monolithic body along the printing direction, and at least two transversely oriented coils are arranged within two respective angular sectors about the longitudinal axis.

[0089] Example 6. A magnetic field sensor as described in Example 5, which is at least one of: (a) three angular sectors and two angular sectors are five aligned sectors arranged around the longitudinal axis of the monolithic body at the same level (same height) relative to the longitudinal axis; and (b) three angular sectors and two angular sectors are 3D printed at different levels (different heights) relative to the longitudinal axis of the monolithic body.

[0090] Example 7. A magnetic field sensor as described in Example 5 or 6, wherein the monolithic body has a cylindrical shape centered on a longitudinal axis with a characteristic width of about 2 millimeters, thereby allowing the magnetic field sensor to be mounted within a catheter.

[0091] Example 8. A magnetic field sensor as described in Example 7, wherein the monolithic body has an annular shape with a hole passing therethrough along the longitudinal axis to facilitate passage of additional components of the catheter (e.g., electrical / fluid lines) through the hole in the sensor, and wherein a pair of opposing magnetic flux collectors for each of the transversely oriented coils includes a magnetic flux collector disposed on an outer surface of the annular shape and a magnetic flux collector located on a surface of the annular shape facing the hole.

[0092] Example 9. 3D printing provides higher voxel resolution along the printing direction compared to lateral voxel resolution within a printed layer; A magnetic field sensor as described in any one of Examples 2 to 8, wherein at least one section functioning as a magnetic core extends substantially parallel to the printing direction and the turns of the second conductive winding surrounding the at least one section are substantially perpendicular to the printing direction, thereby taking advantage of a higher voxel resolution along the printing direction to result in a higher density of the turns of the second conductive winding, thereby improving the sensitivity of the coil oriented in the transverse direction.

[0093] Example 10. A magnetic field sensor according to any one of Examples 2 to 9, wherein at least one magnetic channel is curved in a spiral or serpentine shape.

[0094] Example 11. A magnetic field sensor as described in any one of Examples 2-9, wherein at least one magnetic channel is curved into a coil shape wound around the second conductive winding.

[0095] Example 12. A magnetic field sensor according to any one of Examples 2 to 11, wherein the surface of the magnetic flux collector is larger than at least one section that functions as a magnetic core.

[0096] Example 13. A magnetic field sensor according to any one of Examples 2 to 11, wherein the magnetic channel is configured such that the transversely oriented coils have an open magnetic circuit configuration.

[0097] Example 14. At least one longitudinally oriented coil of the one or more longitudinally oriented coils includes a 3D printed magnetic channel within a monolithic body having a pair of opposing magnetic flux collectors with respective faces perpendicular to a first magnetic axis, and at least one magnetic core section between the pair of opposing magnetic flux collectors; a pair of magnetic flux collectors of longitudinally oriented coils tapered toward a magnetic core section of the longitudinally oriented coils; the magnetic core sections of the longitudinally oriented coils are oriented along said longitudinal direction in the form of rods; - the longitudinally oriented coil magnetic channel is curved into a coil shape wrapped around the first conductive winding; - the magnetic channel of the longitudinally oriented coil is curved within the monolithic body such that a longer length of the core section is surrounded by the first winding of the longitudinally oriented coil, thereby facilitating a higher output voltage and increased sensitivity of the longitudinally oriented coil; at least one longitudinally oriented coil is configured in an open magnetic circuit configuration; and A magnetic field sensor described in any one of Examples 1 to 13, wherein one or more of the following is true: a pair of opposing magnetic flux collectors of a longitudinally oriented coil are arranged from opposing longitudinal sides of the monolithic body of the sensor.

[0098] Example 15. A 3D printable structure formed by 3D printing of at least three different 3D printable materials, the at least three different 3D printable materials comprising: a magnetic material forming a magnetic channel; a conductive material forming a conductive winding; A magnetic field sensor according to any one of the preceding claims, comprising: a non-magnetic dielectric material forming the bulk of the monolithic body in areas where the magnetic and conductive materials are excluded.

[0099] Example 16. A magnetic field sensor as described in Example 15, wherein the spaces between adjacent turns of the winding are occupied by a 3D printed non-electrically conductive material, which is one of a non-magnetic dielectric material and a 3D printed magnetic material, and the conductive material of the winding is completely embedded within the monolithic body so as to be isolated from environmental conditions which may degrade it.

[0100] Example 17. the conductive material comprises silver; the conductive material comprises copper; the conductive material comprises palladium; the conductive material comprises a silver-palladium alloy; the magnetic material comprises a ceramic-ferrite material; the magnetic material comprises a metallic material; - Magnetic materials have a relative permeability μ of 100 or more r and A magnetic field sensor as described in embodiment 15 or 16, wherein the non-magnetic dielectric material is at least one of a ceramic material or a glass-ceramic material.

[0101] Example 18. A magnetic field sensor described in any one of Examples 1 to 17, wherein the electrical contact terminals of the electrical channels of the coil are arranged in a predetermined arrangement on the surface of the monolithic body, and the magnetic field sensor further comprises a signal connector including a printed circuit board (PCB) having a complementary arrangement of contact pads matching the arrangement of the electrical contact terminals of the coil on the surface of the monolithic body, and a signal cable having signal lines electrically coupled to the arrangement of contact pads of the PCB, thereby facilitating electrical connection of the magnetic field sensor by bonding the PCB to the surface of the monolithic body so that the arrangement of the electrical contact terminals is in matching contact with the complementary arrangement of the contact pads of the PCB.

[0102] Example 19. A method for fabricating a magnetic field sensor, the method comprising 3D printing the magnetic field sensor by successive printing of layers along a printing direction to form a monolithic body of the sensor having one or more longitudinally oriented coils having respective first magnetic axes oriented substantially parallel to the printing direction, and one or more transversely oriented coils having respective second magnetic axes oriented transverse to the printing direction.

[0103] Example 20. The 3D printing of each longitudinally oriented coil includes 3D printing of a first conductive channel forming an arrangement of a first conductive winding having planar printed turns in at least some of the printed layers; 3D printing each transversely oriented coil includes 3D printing a magnetic channel including at least a pair of opposing magnetic flux collectors having respective faces perpendicular to the second magnetic axis of the transversely oriented coil and at least one section between the at least one pair of opposing magnetic flux collectors and functioning as a magnetic core of the transversely oriented coil; and 3D printing a second conductive channel forming an arrangement of 3D printed second conductive windings within the monolithic body having turns surrounding the at least one section functioning as the magnetic core; The method of example 19, wherein the magnetic channel is printed in a curved path such that at least one section serving as a magnetic core of a transversely oriented coil extends along a printing direction substantially perpendicular to the second magnetic axis, and turns of the second conductive winding are 3D printed planarly in at least some of the printing layers to surround the magnetic core.

[0104] Example 21. The method of example 20, wherein a pair of magnetic flux collectors are 3D printed across multiple printed layers to have respective magnetic flux collection surfaces perpendicular to the second magnetic axis for efficient collection of magnetic flux propagating from the direction of the second magnetic axis.

[0105] Example 22. 3D printing (a) providing a curable resin, the curable resin comprising: a magnetic material resin comprising particles of magnetic material suspended in a curable polymer binder; a conductive material resin comprising particles of a conductive material suspended in a curable polymer binder; a non-magnetic dielectric material resin comprising particles of non-magnetic dielectric material suspended in a curable polymer binder; (b) 3D printing the curable resin, wherein the 3D printing comprises: 3D printing and curing a magnetic material resin in the region of the magnetic channel; - 3D printing and curing a conductive material resin in the region of the first and second conductive channels; - 3D printing and curing the non-magnetic dielectric material areas of the monolithic body that are not occupied by the magnetic channel and the conductive channel; 3D printing, thereby forming a 3D printed structure of the magnetic field sensor; and The method of any one of Examples 19-21, comprising: (c) sintering the 3D printed structure of the magnetic field sensor at a temperature sufficient to burn or remove the polymer therefrom, thereby achieving near 100% ceramic or metallic density in the magnetic field sensor.

[0106] Example 23. The method of any one of Examples 20-22, wherein the monolithic body is printed in an elongated shape having a relatively short distance between a pair of opposing magnetic flux collectors along the printing direction, and the curvature of the magnetic channel within the monolithic body provides an extended length of at least one section that functions as a magnetic core, facilitating 3D printing of more turns of the second conductive winding around the extended length.

[0107] Example 24. The one or more longitudinally oriented coils include three longitudinally oriented coils of similar magnetic properties, the three longitudinally oriented coils being 3D printed such that they are aligned with one another and their respective first magnetic axes are parallel to one another; The method of any one of Examples 19 to 23, wherein the one or more transversely oriented coils include two transversely oriented coils, the two transversely oriented coils being 3D printed such that their respective two transversely oriented magnetic axes are not parallel to each other and the two transversely oriented magnetic axes span the 3D coordinates together with the longitudinally oriented magnetic axis of at least one of the longitudinally oriented coils of the one or more longitudinally oriented coils.

[0108] Example 25. The method of example 24, wherein at least three longitudinally oriented coils are 3D printed within three respective angular sectors about a longitudinal axis of the monolithic body that is parallel to the printing direction, and at least two transversely oriented coils are disposed within two respective angular sectors about the longitudinal axis.

[0109] Example 26. The method of Example 25, which is at least one of: (a) three angular sectors and two angular sectors are five sectors aligned with each other around the longitudinal axis of the monolithic body, the three angular sectors and two angular sectors being 3D printed at the same level (same height) relative to the longitudinal axis; and (b) three angular sectors and two angular sectors are 3D printed at different levels (different heights) relative to the longitudinal axis of the monolithic body.

[0110] Example 27. The method of example 26 or 25, wherein the monolithic body is 3D printed with a cylindrical shape centered on the longitudinal axis and a characteristic width of about 2 millimeters to allow the magnetic field sensor to be mounted within the catheter.

[0111] Example 28. The method of Example 27, wherein the monolithic body is 3D printed with an annular shape and a hole passing therethrough along the longitudinal axis to facilitate passage of additional components of the catheter (e.g., electrical and / or fluid lines) through the sensor hole, and a pair of opposing magnetic flux collectors for each of the transversely oriented coils are 3D printed such that at least one magnetic flux collector is on an outer surface of the annular shape and at least one magnetic flux collector is on a surface of the annular shape facing the hole.

[0112] Example 29. 3D printing provides higher voxel resolution along the printing direction compared to lateral voxel resolution within a printed layer; The method of any one of Examples 20 to 28, wherein at least one section that functions as a magnetic core of the transversely oriented coil extends substantially parallel to the printing direction and the turns of the second conductive winding surrounding the at least one section are substantially perpendicular to the printing direction, thereby taking advantage of a higher voxel resolution along the printing direction to result in a higher density of the turns of the second conductive winding and improve the sensitivity of the transversely oriented coil.

[0113] Example 30. The method of any one of Examples 19 to 29, wherein at least one magnetic channel of the transversely oriented coil is curved in a spiral or serpentine shape.

[0114] Example 31. The method of any one of Examples 20-29, wherein at least one magnetic channel of the transversely oriented coil is curved into a coil shape wound around the second conductive winding.

[0115] Example 32. The method of any one of Examples 20-31, wherein the surface of the magnetic flux collector is larger than at least one section that functions as a magnetic core.

[0116] Example 33. The method of any one of Examples 20 to 32, wherein the magnetic channel of the transversely oriented coil is configured such that the transversely oriented coil has an open magnetic circuit configuration.

[0117] Example 34. 3D printing at least one longitudinally oriented coil of the one or more longitudinally oriented coils includes 3D printing a magnetic channel in a monolithic body having a pair of opposing magnetic flux collectors having respective faces perpendicular to a first magnetic axis and at least one magnetic core section between the pair of opposing magnetic flux collectors; A pair of magnetic flux collectors of longitudinally oriented coils are 3D printed to taper towards a magnetic core section of the longitudinally oriented coils; - the magnetic core section of the longitudinally oriented coil is 3D printed to extend along the longitudinal direction in the form of a rod; A longitudinally oriented coil magnetic channel is 3D printed to curve into a coil shape wrapped around a first conductive winding; - the magnetic channel of the longitudinally oriented coil is 3D printed in a curved manner within the monolithic body to provide a greater length of the core section surrounded by the first winding of the longitudinally oriented coil; At least one longitudinally oriented coil is 3D printed in an open magnetic circuit configuration; and - A method according to any one of Examples 19 to 33, wherein a pair of opposing flux collectors of a longitudinally oriented coil are 3D printed from opposing longitudinal sides of the monolithic body of the sensor.

[0118] [Embodiment] (1) A magnetic field sensor comprising: a monolithic body having a plurality of coils defined therein by 3D printing of successive printed layers along a printing direction, the plurality of coils comprising: - one or more longitudinally oriented coils having respective first magnetic axes oriented substantially parallel to the printing direction, each of the longitudinally oriented coils including a 3D printed first conductive channel forming a first conductive winding arrangement having turns in the plane of the printed layer; the plurality of coils further includes one or more transversely oriented coils having respective second magnetic axes oriented transversely to the printing direction. (2) each transversely oriented coil of the transversely oriented coils includes: a magnetic channel 3D printed within the monolithic body such that the magnetic channel includes at least a pair of opposing magnetic flux collectors having respective faces perpendicular to the second magnetic axis and at least one section between the at least one pair of opposing magnetic flux collectors that serves as a magnetic core of the transversely oriented coil; and a 3D printed second conductive channel forming an arrangement of a second conductive winding 3D printed within the monolithic body surrounding at least one of the magnetic channels; A magnetic field sensor as described in embodiment 1, wherein the magnetic channel forms a curve within the monolithic body such that the at least one section of the magnetic channel functioning as the magnetic core extends along the printing direction and the arrangement of the second conductive winding includes multiple turns printed within the plane of the printing layer to surround the at least one section functioning as the magnetic core. (3) The magnetic field sensor of embodiment 2, wherein the monolithic body has an elongated shape along the printing direction and has a relatively short distance between the pair of opposing magnetic flux collectors, and the curvature of the magnetic channel within the monolithic body facilitates an extended length of the at least one section functioning as the magnetic core to accommodate more turns of the second conductive winding around the extended length, thereby improving the sensitivity of the transversely oriented coil despite the short distance between the pair of magnetic flux collectors. (4) the one or more longitudinally oriented coils include three longitudinally oriented coils of similar magnetic properties, the three longitudinally oriented coils being 3D printed such that they are aligned with one another and their respective first magnetic axes are parallel to one another, thereby enabling signals obtained from the three longitudinally oriented coils to be utilized to determine two orientation angles of the magnetic field sensor relative to a first magnetic field source located in front of the magnetic field sensor along the general direction of the first magnetic axes; A magnetic field sensor as described in embodiment 1, wherein the one or more transversely oriented coils include two transversely oriented coils that are 3D printed such that their respective two transversely oriented magnetic axes are not parallel to each other and that the two transversely oriented magnetic axes span 3D coordinates with the longitudinally oriented magnetic axis of at least one longitudinally oriented coil of the one or more longitudinally oriented coils, thereby enabling signals obtained from the two transversely oriented coils and the at least one longitudinally oriented coil to be utilized to determine the position and orientation of the sensor relative to one or more second magnetic field sources. (5) A magnetic field sensor as described in embodiment 4, wherein the at least three longitudinally oriented coils are arranged within three respective angular sectors about a longitudinal axis of the monolithic body along the printing direction, and the at least two transversely oriented coils are arranged within two respective angular sectors about the longitudinal axis.

[0119] (6) The magnetic field sensor of embodiment 5, wherein at least one of: (a) the three angular sectors and the two angular sectors are five sectors aligned with each other and arranged at the same level around the longitudinal axis of the monolithic body; and (b) the three angular sectors and the two angular sectors are each arranged at different levels of the monolithic body. (7) A magnetic field sensor as described in embodiment 4, wherein the monolithic body has a cylindrical shape centered on the longitudinal axis with a characteristic width of about 2 millimeters, thereby enabling the magnetic field sensor to be mounted within a catheter. (8) The magnetic field sensor of embodiment 7, wherein the monolithic body has an annular shape with a hole passing therethrough along the longitudinal axis to facilitate passage of additional components of the catheter (e.g., electrical / fluid lines) through the hole of the sensor, and the pair of opposing magnetic flux collectors of each of the transversely oriented coils includes a magnetic flux collector disposed on an outer surface of the annular shape and a magnetic flux collector located on a surface of the annular shape facing the hole. (9) the 3D printing provides a higher voxel resolution along the printing direction compared to a lateral voxel resolution within a printed layer; A magnetic field sensor as described in embodiment 2, wherein the at least one section functioning as the magnetic core extends substantially parallel to the printing direction and the turns of the second conductive winding surrounding the at least one section are substantially perpendicular to the printing direction, thereby taking advantage of the higher voxel resolution along the printing direction to provide a higher density of the turns of the second conductive winding, thereby improving the sensitivity of coils oriented in the transverse direction. (10) A magnetic field sensor as described in embodiment 2, wherein at least one of the magnetic channels is curved in a spiral or serpentine shape.

[0120] (11) A magnetic field sensor as described in embodiment 2, wherein at least one of the magnetic channels is curved into a coil shape wound around the second conductive winding. (12) A magnetic field sensor as described in embodiment 2, wherein the surface of the magnetic flux collector is wider than the at least one section that functions as the magnetic core. (13) A magnetic field sensor as described in embodiment 2, wherein the magnetic channel is configured such that the transversely oriented coils have an open magnetic circuit configuration. (14) At least one longitudinally oriented coil of the one or more longitudinally oriented coils includes a 3D printed magnetic channel within the monolithic body having a pair of opposing magnetic flux collectors with respective faces perpendicular to the first magnetic axis and at least one magnetic core section between the pair of opposing magnetic flux collectors; the pair of magnetic flux collectors of the longitudinally oriented coils are tapered toward the magnetic core section of the longitudinally oriented coils; the magnetic core sections of the longitudinally oriented coils are oriented along the longitudinal direction in the form of a rod; the magnetic channel of the longitudinally oriented coil is curved into a coil shape wrapped around the first conductive winding; - the magnetic channel of the longitudinally oriented coil is curved within the monolithic body such that a longer length of the core section is surrounded by the first winding of the longitudinally oriented coil, thereby facilitating a higher output voltage and increased sensitivity of the longitudinally oriented coil; the at least one longitudinally oriented coil is configured in an open magnetic circuit configuration; and -The pair of opposing magnetic flux collectors of the longitudinally oriented coil are arranged from opposing longitudinal sides of the monolithic body of the sensor. (15) A 3D printing apparatus comprising: a magnetic material forming a magnetic channel of said coil; - a conductive material forming an electrical channel of said coil; - a non-magnetic dielectric material forming the bulk of the monolithic body in areas where the magnetic material and the conductive material are excluded.

[0121] (16) A magnetic field sensor as described in embodiment 15, wherein the spaces between adjacent turns of the winding are occupied by a 3D printed non-electrically conductive material, which is one of the non-magnetic dielectric material and the 3D printed magnetic material. (17)-The conductive material comprises silver. - the conductive material comprises copper; the conductive material comprises palladium; the conductive material comprises a silver-palladium alloy; - the magnetic material comprises a ceramic-ferrite material; the magnetic material comprises a metallic material; The magnetic material has a relative permeability μ of about 100 or more. r and -A magnetic field sensor as described in embodiment 15, wherein the non-magnetic dielectric material is at least one of a ceramic material or a glass-ceramic material. (18) The magnetic field sensor of embodiment 1, wherein electrical contact terminals of the electrical channels of the coil are arranged in a predetermined arrangement on the surface of the monolithic body, and the magnetic field sensor further includes a signal connector including a printed circuit board (PCB) having a complementary arrangement of contact pads matching the arrangement of the electrical contact terminals of the coil on the surface of the monolithic body, and a signal cable having signal lines electrically coupled to the arrangement of contact pads of the PCB, thereby facilitating electrical connection of the magnetic field sensor by coupling the PCB to the surface of the monolithic body such that the arrangement of the electrical contact terminals is in matching contact with the complementary arrangement of contact pads of the PCB. (19) A method for fabricating a magnetic field sensor, comprising the steps of: The method includes 3D printing the magnetic field sensor by successive printing of layers along a printing direction to form a monolithic body of the sensor having one or more longitudinally oriented coils having respective first magnetic axes oriented substantially parallel to the printing direction, and one or more transversely oriented coils having respective second magnetic axes oriented transverse to the printing direction. (20) 3D printing each longitudinally oriented coil includes 3D printing a first conductive channel forming an arrangement of a first conductive winding having planar printed turns in at least some of the printed layers; 3D printing each transversely oriented coil includes 3D printing a magnetic channel including at least a pair of opposing magnetic flux collectors having respective faces perpendicular to the second magnetic axis of the transversely oriented coil and at least one section between the at least a pair of opposing magnetic flux collectors that functions as a magnetic core of the transversely oriented coil, and 3D printing a second conductive channel forming an arrangement of 3D printed second conductive windings within the monolithic body having turns surrounding the at least one section that functions as the magnetic core; 20. The method of claim 19, wherein the magnetic channel is printed in a curved path such that the at least one section that serves as the magnetic core of the transversely oriented coil extends along the printing direction substantially perpendicular to the second magnetic axis, and the turns of the second conductive winding are 3D printed planarly in at least some of the printing layers to surround the magnetic core.

[0122] (21) The method of claim 20, wherein the pair of magnetic flux collectors are 3D printed across a plurality of the printed layers to have respective magnetic flux collection surfaces perpendicular to the second magnetic axis for efficient collection of magnetic flux propagating from the direction of the second magnetic axis. (22) The 3D printing (a) providing a curable resin, the curable resin comprising: a magnetic material resin comprising particles of magnetic material suspended in a curable polymer binder; a conductive material resin comprising particles of a conductive material suspended in a curable polymer binder; a non-magnetic dielectric material resin comprising particles of non-magnetic dielectric material suspended in a curable polymer binder; (b) 3D printing the curable resin, the 3D printing comprising: - 3D printing and curing said magnetic material resin in the region of the magnetic channel of said coil; - 3D printing and curing the conductive material resin in the area of ​​the conductive channel of the coil; - 3D printing and curing the non-magnetic dielectric material regions of the monolithic body that are not occupied by the magnetic channel and the conductive channel; 3D printing, thereby forming a 3D printed structure of the magnetic field sensor; and 20. The method of claim 19, comprising: (c) sintering the 3D printed structure of the magnetic field sensor at a temperature sufficient to burn or remove polymer therefrom, thereby achieving near 100% ceramic or metallic density in the magnetic field sensor.

Claims

1. A magnetic field sensor, a monolithic body having a plurality of coils defined therein by 3D printing of successive printed layers along a printing direction, the plurality of coils comprising: one or more longitudinally oriented coils having respective first magnetic axes oriented substantially parallel to the printing direction, each of the longitudinally oriented coils including a 3D printed first conductive channel forming a first conductive winding arrangement having turns in the plane of the printed layer; a magnetic field sensor, wherein the plurality of coils further comprises one or more transversely oriented coils having respective second magnetic axes oriented transversely to the printing direction.

2. each transversely oriented coil of the transversely oriented coils comprises: a magnetic channel 3D printed within the monolithic body such that the magnetic channel includes at least a pair of opposing magnetic flux collectors having respective faces perpendicular to the second magnetic axis, and at least one section between the at least one pair of opposing magnetic flux collectors that serves as a magnetic core of the transversely oriented coil; and a 3D printed second conductive channel forming an arrangement of a second conductive winding 3D printed within the monolithic body surrounding at least one of the magnetic channels; 2. The magnetic field sensor of claim 1, wherein the magnetic channel forms a curve in the monolithic body such that the at least one section of the magnetic channel that functions as the magnetic core extends along the printing direction and the arrangement of the second conductive winding includes a plurality of turns printed in the plane of the printing layer to surround the at least one section that functions as the magnetic core.

3. 3. The magnetic field sensor of claim 2, wherein the monolithic body has an elongated shape along the printing direction and has a relatively short distance between the pair of opposing magnetic flux collectors, and the curvature of the magnetic channel within the monolithic body facilitates an extended length of the at least one section functioning as the magnetic core to accommodate more turns of the second conductive winding around the extended length, thereby improving sensitivity of the transversely oriented coil despite the short distance between the pair of magnetic flux collectors.

4. the one or more longitudinally oriented coils include three longitudinally oriented coils of similar magnetic properties, the three longitudinally oriented coils being 3D printed such that they are aligned with one another and their respective first magnetic axes are parallel to one another, thereby enabling signals obtained from the three longitudinally oriented coils to be utilized to determine two orientation angles of the magnetic field sensor relative to a first magnetic field source located in front of the magnetic field sensor along a general direction of the first magnetic axis; 2. The magnetic field sensor of claim 1, wherein the one or more transversely oriented coils include two transversely oriented coils that are 3D printed such that their respective two transversely oriented magnetic axes are not parallel to one another and that the two transversely oriented magnetic axes span 3D coordinates with a longitudinally oriented magnetic axis of at least one longitudinally oriented coil of the one or more longitudinally oriented coils, thereby enabling signals obtained from the two transversely oriented coils and the at least one longitudinally oriented coil to be utilized to determine a position and orientation of the sensor relative to one or more second magnetic field sources.

5. 5. The magnetic field sensor of claim 4, wherein the at least three longitudinally oriented coils are arranged within three respective angular sectors about a longitudinal axis of the monolithic body along the printing direction, and the at least two transversely oriented coils are arranged within two respective angular sectors about the longitudinal axis.

6. 6. The magnetic field sensor of claim 5, wherein at least one of: (a) the three angular sectors and the two angular sectors are five sectors aligned with each other and disposed at the same level around the longitudinal axis of the monolithic body; and (b) the three angular sectors and the two angular sectors are each disposed at different levels of the monolithic body.

7. 5. The magnetic field sensor of claim 4, wherein the monolithic body has a cylindrical shape centered on the longitudinal axis with a characteristic width of about 2 millimeters, thereby enabling the magnetic field sensor to be mounted within a catheter.

8. 8. The magnetic field sensor of claim 7, wherein the monolithic body has an annular shape with a hole passing therethrough along the longitudinal axis to facilitate passage of additional components of the catheter (e.g., electrical / fluid lines) through the hole of the sensor, and the pair of opposing magnetic flux collectors of each of the transversely oriented coils includes a magnetic flux collector disposed on an outer surface of the annular shape and a magnetic flux collector located on a surface of the annular shape facing the hole.

9. the 3D printing provides a higher voxel resolution along the printing direction compared to a lateral voxel resolution within a printed layer; 3. The magnetic field sensor of claim 2, wherein the at least one section functioning as the magnetic core extends substantially parallel to the printing direction and the turns of the second conductive winding surrounding the at least one section are substantially perpendicular to the printing direction, thereby taking advantage of the higher voxel resolution along the printing direction to provide a higher density of the turns of the second conductive winding, thereby improving the sensitivity of the transversely oriented coils.

10. The magnetic field sensor of claim 2 , wherein at least one of the magnetic channels is curved in a spiral or serpentine shape.

11. The magnetic field sensor of claim 2 , wherein at least one of the magnetic channels is curved into a coil shape wrapped around the second conductive winding.

12. The magnetic field sensor of claim 2 , wherein the face of the magnetic flux collector is larger than the at least one section that functions as the magnetic core.

13. The magnetic field sensor of claim 2 , wherein the magnetic channel is configured such that the transversely oriented coils have an open magnetic circuit configuration.

14. at least one longitudinally oriented coil of the one or more longitudinally oriented coils includes a 3D printed magnetic channel in the monolithic body having a pair of opposing magnetic flux collectors having respective faces perpendicular to the first magnetic axis and at least one magnetic core section between the pair of opposing magnetic flux collectors; the pair of magnetic flux collectors of the longitudinally oriented coils are tapered towards the magnetic core section of the longitudinally oriented coils; the magnetic core sections of the longitudinally oriented coils are oriented along the longitudinal direction in the form of rods; the magnetic channel of the longitudinally oriented coil is curved in the shape of a coil wrapped around the first conductive winding; - the magnetic channel of the longitudinally oriented coil is curved within the monolithic body such that a longer length of the core section is surrounded by the first winding of the longitudinally oriented coil, thereby facilitating a higher output voltage and increased sensitivity of the longitudinally oriented coil; - the at least one longitudinally oriented coil is configured in an open magnetic circuit configuration; and A magnetic field sensor as described in any one of claims 1 to 13, characterized in that the pair of opposing magnetic flux collectors of the longitudinally oriented coil are arranged from opposing longitudinal sides of the monolithic body of the sensor.

15. formed by 3D printing of at least three different 3D printable materials, said at least three different 3D printable materials comprising: - a magnetic material forming the magnetic channel of said coil; - a conductive material forming the electrical channel of said coil; a non-magnetic, dielectric material forming the bulk of the monolithic body in areas where the magnetic material and the conductive material are excluded.

16. 16. The magnetic field sensor of claim 15, wherein spaces between adjacent turns of the winding are occupied by a 3D printed non-electrically conductive material that is one of the non-magnetic dielectric material and the 3D printed magnetic material.

17. - the conductive material comprises silver; - said conductive material comprises copper; - the conductive material comprises palladium; - the conductive material comprises a silver-palladium alloy; - said magnetic material comprises a ceramic-ferrite material; - the magnetic material comprises a metallic material, The magnetic material has a relative permeability μ of about 100 or more. ｒ and The magnetic field sensor according to claim 15, wherein the non-magnetic dielectric material comprises at least one of a ceramic material or a glass-ceramic material.

18. 2. The magnetic field sensor of claim 1, wherein electrical contact terminals of the electrical channels of the coil are arranged in a predetermined arrangement on the surface of the monolithic body, and the magnetic field sensor further includes a signal connector including a printed circuit board (PCB) having a complementary arrangement of contact pads matching the arrangement of the electrical contact terminals of the coil on the surface of the monolithic body, and a signal cable having signal lines electrically coupled to the arrangement of the contact pads of the PCB, thereby facilitating electrical connection of the magnetic field sensor by bonding the PCB to the surface of the monolithic body such that the arrangement of the electrical contact terminals is in matching contact with the complementary arrangement of the contact pads of the PCB.

19. 1. A method for fabricating a magnetic field sensor, comprising: The method includes 3D printing the magnetic field sensor by successive printing of layers along a printing direction to form a monolithic body of the sensor having one or more longitudinally oriented coils having respective first magnetic axes oriented substantially parallel to the printing direction, and one or more transversely oriented coils having respective second magnetic axes oriented transverse to the printing direction.

20. 3D printing each longitudinally oriented coil includes 3D printing a first conductive channel forming an arrangement of a first conductive winding having planar printed turns in at least some of the printed layers; 3D printing each transversely oriented coil includes 3D printing a magnetic channel including at least a pair of opposing magnetic flux collectors having respective faces perpendicular to the second magnetic axis of the transversely oriented coil and at least one section between the at least a pair of opposing magnetic flux collectors that functions as a magnetic core of the transversely oriented coil, and 3D printing a second conductive channel forming an arrangement of a 3D printed second conductive winding within the monolithic body having turns surrounding the at least one section that functions as the magnetic core; 20. The method of claim 19, wherein the magnetic channel is printed in a curved path such that the at least one section that serves as the magnetic core of the transversely oriented coil extends along the printing direction substantially perpendicular to the second magnetic axis, and the turns of the second conductive winding are 3D printed planarly in at least some of the printed layers to surround the magnetic core.

21. 21. The method of claim 20, wherein the pair of magnetic flux collectors are 3D printed across multiple printed layers to have respective flux collecting surfaces perpendicular to the second magnetic axis for efficient collection of magnetic flux propagating from the direction of the second magnetic axis.

22. The 3D printing is (a) providing a curable resin, the curable resin comprising: a magnetic material resin comprising particles of magnetic material suspended in a curable polymer binder; a conductive material resin comprising particles of conductive material suspended in a curable polymer binder; a non-magnetic dielectric material resin comprising particles of non-magnetic dielectric material suspended in a curable polymer binder; (b) 3D printing the curable resin, the 3D printing comprising: - 3D printing and hardening said magnetic material resin in the area of ​​the magnetic channel of said coil; - 3D printing and curing said conductive material resin in the area of ​​the conductive channel of said coil; - 3D printing and curing the non-magnetic dielectric material areas of the monolithic body that are not occupied by the magnetic channels and the conductive channels; 3D printing, thereby forming a 3D printed structure of the magnetic field sensor; and 20. The method of claim 19, comprising: (c) sintering the 3D printed structure of the magnetic field sensor at a temperature sufficient to burn or remove polymer therefrom, thereby achieving near 100% ceramic or metallic density in the magnetic field sensor.

Images