Magnetic field sensor

Abstract

The invention discloses a magnetic field sensor and a 3D printing method thereof. The magnetic field sensor includes a monolithic body having a plurality of coils 3D printed therein by continuously printing layers in a printing direction; the coils include longitudinally oriented coils whose magnetic axes are parallel to the printing direction and laterally oriented coils whose magnetic axes are perpendicular to the printing direction. Each of the laterally oriented coils is 3D printed with a magnetic channel curved between a pair of opposing flux collecting faces perpendicular to its magnetic axis such that it includes a magnetic core section extending along the printing direction. Each of the longitudinally and laterally oriented coils is 3D printed with a respective arrangement of conductive windings comprising a plurality of turns 3D printed in the plane of the 3D printed layers. The turns of the laterally oriented coil surround the magnetic core section to its magnetic channels.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 533,258, filed on August 17, 2023, the contents of which are incorporated by reference as if set forth in full herein. Technical Field

[0003] The present invention is in the field of magnetic field sensors and in particular relates to techniques for manufacturing magnetic field sensors suitable for magnetic field-based position sensing, in particular for sensing the position of a medical device. Background Art

[0004] In various therapeutic and diagnostic procedures, a catheter / probe is inserted into a patient's body (e.g., a cardiac chamber) and brought into contact with body tissue therein. Typically, in such procedures, it is necessary to determine the position of the catheter in the body (i.e., the position where the distal end of the catheter engages the body tissue) and the pressure applied by the catheter to the tissue.

[0005] Catheters with integrated position and pressure sensors for sensing the position of the catheter and the pressure / force applied by the catheter at the contact area with the tissue are generally known. Such catheters generally utilize inductive coils to determine the position of the catheter within the body and / or the pressure / force applied by the catheter to the body tissue engaged therewith.

[0006] Conventional technology for such catheters typically utilizes a wire-wound coil into which a ferrite core can be manually inserted after winding. The coil manufactured in this manner is then soldered to a cable that carries the coil signal to processing circuitry and assembled within the catheter body. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to better understand the subject matter disclosed herein and to illustrate how the subject matter may be implemented in practice, various embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:

[0008] Figure 1A An integral magnetic field sensor 100 having a plurality of coils 120 including longitudinally oriented coils 120L and transversely oriented coils 120T 3D printed therein is illustrated in accordance with an embodiment of the present invention;

[0009] Figure 1B and Figure 1C 1 respectively illustrate a longitudinally oriented coil 120L and a transversely oriented coil 120T that may be included / 3D printed in the integrated magnetic field sensor 100 of FIG. 1 according to some embodiments of the present invention;

[0010] Figure 1D and Figure 1E They are exemplified Figure 1B and Figure 1C The magnetic channel of the #D printed coil shown in;

[0011] Figure 2A , Figure 2B , Figure 2C and Figure 2D illustrates several views of a transversely oriented coil 120T having a magnetic channel bent / folded into a helical shape that may be 3D printed / included in an integrated magnetic field / positioning sensor 100 according to some embodiments of the present invention;

[0012] Figure 3A , Figure 3B and Figure 3C illustrates several views of a transversely oriented coil 120T having a magnetic channel 129T with a multi-helix shape (a double helix in this example) that may be 3D printed / included in an integrated magnetic field / positioning sensor 100 according to some embodiments of the present invention;

[0013] Figure 4A illustrates a transversely oriented coil 120T having a magnetic channel bent / folded into a meander-like shape that may be 3D printed / included in an integrated magnetic field / positioning sensor 100 according to some embodiments of the present invention;

[0014] Figure 4B Illustrated Figure 4A A cross-sectional view of a coil;

[0015] Figure 5A and Figure 5B illustrates several views of a longitudinally oriented coil 120L having a magnetic channel bent / folded into a coil-like shape wrapped around a conductive winding that may be 3D printed / included in an integrated magnetic field / positioning sensor 100 according to some embodiments of the present invention;

[0016] Fig. 6A depicts a side view of a medical device 1000 equipped with an integrated five-axis magnetic field-based positioning sensor 100 in accordance with an embodiment of the present invention;

[0017] Figure 6B A perspective view illustrating the internal structure of a magnetic field sensor 100 provided in a medical device 1000 is depicted;

[0018] Figure 6C depicts a perspective view illustrating a flux collector configuration of a magnetic field sensor 100 provided in a medical device 1000 according to some embodiments of the present invention;

[0019] Fig.6Ddepicts a perspective view illustrating the arrangement of electrical contacts / terminals of longitudinally and transversely oriented coils of magnetic field sensor 100 arranged at their outer surfaces;

[0020] Fig. 6E and Fig. 6F are respectively illustrated as being configured for use with Fig.6D The electrical contacts / terminals of the magnetic field sensor 100 illustrated in the example are connected / coupled to the rear and front sides of the signal connector; and

[0021] Figure 7 is a flow chart of a method 200 of manufacturing a magnetic field / positioning sensor 100 by 3D printing technology according to some embodiments of the present invention. DETAILED DESCRIPTION

[0022] The catheter art requires physically flexible and sensitive catheters with compact / narrow dimensions that can provide accurate feedback regarding the catheter's position in the body, the contact interface between the catheter and tissue, and the forces (eg, vectors) applied therebetween.

[0023] U.S. Patent No. 8,535,308 and U.S. Patent Application No. US2020 / 015693, both assigned to the assignee of the present application, disclose configurations of such catheters, for example utilizing sensing circuits having several coils for sensing the position and orientation of the catheter body and the forces applied by the catheter at the interface with the tissue.

[0024] One challenge in the field of such catheters is to fit accurate position and force sensors within the narrow body of the catheter, which typically has only a few millimeters in lateral dimensions. Indeed, as noted above, in conventional catheter technology, position and force sensors typically utilize a miniature wire-wound coil into which a ferrite core can be manually inserted in an open magnetic circuit configuration in order to generate sufficient induced voltages suitable for position and force sensing of the catheter components. However, these conventional techniques are time consuming and expensive, and involve delicate manual manipulations for fitting the coil within the small dimensions of the catheter body.

[0025] Therefore, there is a need in the art for more efficient, cost-effective techniques for manufacturing such catheters and for manufacturing small, highly sensitive coils (i.e., having a high induced voltage in response to a magnetic field) suitable for position and / or force sensing in catheters such as those disclosed above. In addition, there is a need in the art for automated manufacturing techniques for such coils to produce standardized coils with less variability between manufactured coils of the same design. In addition, to facilitate further emergence in the catheter field, there is a need in the art for facilitating size reduction and / or impedance / induced voltage improvement to improve one or both of the sensitivity and flexibility of the catheter and / or reduced size.

[0026] The present invention provides novel positioning sensing systems and novel configurations and methods of manufacture for magnetic field sensors including open magnetic circuit coils suitable for high induced voltage magnetic sensors, such as for use as position sensors fitted within the narrow dimensions of a catheter body.

[0027] Figures 1A to 1E A magnetic field sensor 100 (e.g., a multi-axis magnetic field-based positioning sensor) according to an embodiment of the present invention is illustrated. The magnetic field sensor 100 includes a monolithic body 110 having a plurality of coils 120 defined / fabricated therein by multi-material 3D printing of successive printing layers along a printing direction Z.

[0028] According to the technology of the present invention, the magnetic field sensor 100 is manufactured by 3D printing of at least three different 3D printable materials M1 to M3, including:

[0029] - At least one type of magnetic material M1 which is used / 3D printed to form the magnetic channel 129 of the coil 120, which typically includes the magnetic core 122 of the coil 120 and typically also includes its magnetic flux collector 126 as described below.

[0030] - at least one type of electrically conductive (usually non-magnetic) material M2, which is used

[0031] / 3D printing to form a conductive channel 128 of the coil 120, the conductive channel including the conductive winding 124 and its contact terminal 123; and

[0032] - At least one type of non-magnetic material, and typically a dielectric / non-conductive material M3, which is used / 3D printed to form the bulk of the monolithic body 110 of the sensor 100 at areas where magnetic and conductive materials are excluded.

[0033] The spaces between adjacent windings / turns 124 are occupied by 3D printed non-conductive material. This non-conductive material may be, for example, a non-magnetic dielectric material M3 3D printed in the bulk of the monolithic body 110 and / or a magnetic material M1 used to print magnetic channels if it is non-conductive.

[0034] According to some aspects of the present invention, the sensor 100 is manufactured using a 3D printing method (additive manufacturing technology), such as the following reference Figure 73D printing method described in more detail. The 3D printing method includes depositing at least three printable materials M1 to M3 layer by layer along the printing direction Z. Typically, the at least 3 types of printable materials include: a magnetic material M1, which is used to print the magnetic channel 129 of the coil 120 (including the magnetic core 122 and its flux collector 126); a conductive material M2, which is used to print the electrical channel 128 of the coil (including the conductive winding 124 and the electrical contact 123); and a non-magnetic electrically insulating (dielectric) material, which is 3D printed to form a block of the monolithic body 110 of the sensor 100, and typically / optionally fills the gaps between the windings 124 of the coil to electrically insulate between these windings.

[0035] The term magnetic material and / or particles is used herein to refer to particles having a high relative magnetic permeability μ r For example, a material having a magnetic permeability μ0 relative to vacuum is preferably μ r ≥100, and in some cases more preferably about μ r ≥500, or even about In contrast, the term non-magnetic material and / or particle is used herein to denote a low relative magnetic permeability μ r The relative magnetic permeability of the material is substantially lower than that of the magnetic materials used in the manufacture of electronic components and is typically μ r The order of magnitude is ~1.

[0036] exist Figures 1A to 6B , various 3D printable aspects / parts of the magnetic field sensor 100 are illustrated, wherein the corresponding legend indicates the color / tone codes used in each figure to specify the different 3D printable materials M1 to M3 used in the printing of each aspect / part. In this regard, it is noted that in some figures (e.g. Figures 1B to 5B and Figure 6B In some figures, the bulk material M3 of the monolithic body 110 is not specifically shown so as not to obscure the figure. In addition, in some figures, the same material, such as magnetic material, is marked with two different color / tone codes in order to emphasize / distinguish different functional parts / sections made of the same material.

[0037] Figures 1A to 1E The plurality of coils 120 in the example of the magnetic field sensor 100 illustrated in comprises one or more longitudinally oriented coils 120L and one or more transversely oriented coils 120T. The phrases longitudinally oriented coils and transversely oriented coils are used herein to designate coils whose respective magnetic axes are oriented substantially parallel to the printing direction Z and transversely with respect to the printing direction Z, respectively.

[0038] Each of the coils 120 includes at least one electrical channel 128 3D printed in the monolithic body 110 using a 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 a plurality of 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 respective magnetic axis of the coil) into an induced voltage at its electrical contact 123. The electrical channel 128 is typically configured so that the electrical contacts 123 are arranged from one side of the monolithic body 110, so that electrical connections to the electrical contacts can be made efficiently, for example, through one electrical connector, and / or to facilitate assembly of electrical components in a narrow space without access to different sides thereof with electrical / signal connection lines.

[0039] Each of the transversely oriented coils 120T and typically (optionally) each of the longitudinally oriented coils 120L also includes a coil having a relative magnetic permeability μ of typically about one hundred (several hundred) or more. r The magnetic material M1 is 3D printed in at least one magnetic channel 129 in the monolithic body 110 .

[0040] The magnetic channels 129 are 3D printed to include respective magnetic cores 122 surrounded by the conductive windings 124 of the electrical channels 128 of their respective coils. The magnetic channels 129 are thus configured and operable to direct / guide and optionally concentrate external magnetic flux directed along the respective magnetic axes of the coils to flow / through the windings 124 of the coils to improve / increase the induced voltage at the electrical contacts 123 of the coils and thus improve / increase their sensitivity. The magnetic channels 129 of each of the transversely oriented coils 120T also include magnetic flux collectors 126T coupled from opposite ends of the magnetic channels 128 and having relatively large flux collecting facets / surfaces 126F and 126B facing the magnetic axes (e.g., T1 and / or T2) of their respective transversely oriented coils 120T. In a longitudinally oriented coil 120L having a magnetic channel 129, the magnetic channel 129 typically also includes magnetic flux collectors 126L that are coupled from opposite ends of the magnetic core 122 and have relatively large flux collecting facets / surfaces 126U and 126D facing the longitudinal magnetic axis (e.g., L1, L2 and / or L3) of the corresponding coil. Figure 1D and Figure 1E Magnetic channels 129L and 129T are illustrated and illustrated for the longitudinal and transverse oriented coils, respectively. For clarity, magnetic channels 129L and 129T are shown surrounded by outlines marking conductive windings 124L and 124T for the longitudinal and transverse oriented coils, respectively.

[0041] Figure 1B and Figure 1C Examples of longitudinally oriented coils 120L and transversely oriented coils 120L fabricated in the unitary body 110 of the sensor 100 are illustrated, respectively. Figure 1B A longitudinally oriented coil 120L is illustrated that includes a magnetic channel 129L formed / 3D printed from a magnetic material M1 defining a magnetic core 122L of the coil, and an electrical channel 124L including an electrically conductive winding 128L having a plurality of electrically conductive turns surrounding the magnetic core 122L of the coil 120L. Figure 1C A transversely oriented coil 120T is illustrated that includes a magnetic channel 129T formed / 3D printed with a magnetic material M1 defining a magnetic core 122T of the coil, and an electrical channel 128T including a conductive winding 124T having a plurality of conductive turns surrounding the magnetic core 122T of the coil 120T.

[0042] It should be noted that the magnetic channel 129 of any one or more of the coils 120 need not define a single magnetic path (e.g., passing between a pair of flux collectors 126 of the coil), and in some embodiments, the magnetic channel can be split into multiple sub-magnetic channels defining multiple magnetic cores of the corresponding coil, each magnetic core 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 need not define a single conductive path between a pair of electrical contacts 123 of the coil, and in some embodiments, the electrical channel can be split into multiple sub-electrical channels defining multiple winding sets around the same or different sections of the magnetic core 122 of the coil.

[0043] In some embodiments, the 3D printing technology used for the manufacture of the sensor 100 provides for printing layers having a thickness significantly less than the minimum feature size that can be printed within the layer (in other words: the inter-layer resolution is significantly higher than the resolution of the features / pixels within the layer that can be 3D printed; or the inter-layer spacing is greater than the minimum spacing of the features / pixels within the layer). For example, in certain non-limiting examples, the sensor 100 may be printed using a 3D printing technology that provides a lateral, intra-layer, minimum feature size of about 24 microns to 50 microns (μm) sintered along each of the lateral X-axis and Y-axis, while the thickness of the sintered printed layer is much smaller, about 9 μm to 10 μm. It is noted that the minimum intra-layer feature size is considered to be twice the lateral size of the pixel, and the spacing of the pixels is about 12 μm to 25 μm. This is because in practice, in some cases / embodiments, the functional intra-layer features of the sensor (e.g., conductive wire turns and / or electrically insulating material between them) are printed with a lateral width of at least two pixels, so that the printing is reliable and robust to prevent erroneous printing of pixels within the layer. In such embodiments, printing the conductive turns planarly within the print layer facilitates achieving approximately three times / more than three times the turn count / density as compared to that achievable by printing the turns perpendicular to / across the print layer.

[0044] Furthermore, in some embodiments, the magnetic field sensor 100 is manufactured with its unitary body 110 having an elongated shape such that its length H along the longitudinal axis / printing direction Z is significantly greater than its characteristic lateral width W (e.g., aspect ratio H / W>>1) to facilitate mounting the sensor 100 in, for example, 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 embodiments, the magnetic channel 129 of the transversely oriented coil 120T is bent to extend along the printing direction Z and the stack of conductive turns of the coil winding 124T stacked along the printing direction Z is printed and each winding is 3D printed planarly within the printing layer to surround the magnetic channel 129, facilitating the manufacture of a higher count of conductive turns and therefore better sensitivity of the transversely oriented coil 120T.

[0045] In fact, for longitudinally oriented coils, such as Figure 1B120L illustrated in FIG. 120L (whose magnetic axis L (e.g., in this example, L1, L2, and L3) is parallel to the printing direction Z, and these longitudinally oriented coils are designated to sense magnetic flux propagating along the printing direction Z), printing the conductive turns of the coil winding 124L planarly within the printed layer can be relatively straightforward because when the turns of the conductive winding 124L are planarly oriented in the printed layer, they are inherently located in a plane substantially perpendicular to the magnetic flux axis L of the longitudinally oriented coil 120L (at the magnetic axis L parallel to the printing direction Z).

[0046] However, printing only the turns of the conductive winding 124T of the transversely oriented coil 120T in a planar orientation in a printed layer is not sufficient to facilitate sensing of the magnetic flux propagating along the magnetic axis T of the transversely oriented coil 120T because the transversely oriented coil such as Figure 1C The magnetic axis T of 120T illustrated in FIG. 1 is directed transversely (eg, perpendicularly) to the printing direction Z, and in order to capture the flux, the turns of the conductive winding 124T should conventionally be arranged perpendicular to the magnetic axis T.

[0047] Therefore, in order to overcome this disadvantage and facilitate printing the turns of the conductive winding 124T of the transversely oriented coil 120T in the print layer in a parallel orientation to produce a higher turn count / density, each transversely oriented coil 120T is 3D printed in a monolithic body 110 (having a magnetic channel 122T including at least a pair of opposing flux collectors 126T, which define / have corresponding relatively large facets / surfaces 126F and 126B facing the magnetic axis T of the transversely oriented coil 120T (for example, substantially perpendicular to the magnetic axis T)), so that the magnetic channel 129T is bent / folded 127 so that one or more sections 122T thereof serving as the magnetic core of the transversely oriented coil 120T extend along a direction perpendicular / cross-to-the-magnetic axis T of the transversely oriented coil 120T. Thus, where the magnetic channel 129T is bent / folded 127 so that its magnetic core 122T extends substantially perpendicular to its magnetic axis T (e.g., in a direction intersecting its magnetic axis), magnetic flux from the direction of the transverse magnetic axis T of the coil can be collected by the flux collector 126T and directed through the magnetic core 122T extending perpendicular thereto. In turn, the turns (at least some of them) of the conductive winding 124T of the transversely oriented coil 120T are printed within the print layer in a planar orientation so that they surround the magnetic core 122T and can capture / sense magnetic flux directed from the direction of the transversely oriented magnetic axis T of the transversely oriented coil 120T to a path through the magnetic core. In other words, magnetic channel 129 is configured and operable to collect magnetic field flux directed substantially along magnetic axis T of transversely oriented coil 120T via facets 126F and 126B of flux collector 126T, and direct the flux flow through magnetic core 122T extending substantially perpendicularly (or more generally in an intersecting direction of the magnetic axis) relative to magnetic axis T. In other words, the magnetic core geometry causes the magnetic field propagating inside magnetic core 122T to flip 90° relative to the external magnetic field.

[0048] In this way, the techniques of the present invention facilitate planar 3D printing of turns of the conductive windings 124 of both longitudinally and transversely oriented coils 120L and 120T within the plane of the printed layer (i.e., within a plane substantially perpendicular to the printing direction Z), and thereby produce a higher count of turns of the coil 120 and improved sensitivity of the sensor 100.

[0049] In this regard, it should be noted that, according to some embodiments, the flux collectors 126T and in particular their facets / surfaces 126F and 126B facing the magnetic axis T of the transversely oriented coil 120T are typically made wider (e.g., have a significantly larger area) than the characteristic width (e.g., cross-sectional area) of the magnetic channel 122T therebetween. More specifically, the area of ​​the facets / surfaces 126F and 126B of the flux collectors is typically made significantly larger than the characteristic cross-sectional area of ​​the magnetic core segment 122T of the magnetic channel 129 extending perpendicular to the magnetic axis T, such that the flux collectors 126T collect a much larger amount of magnetic field flux from the direction of the magnetic axis T than the amount of flux that would be collected into the magnetic channel from other directions, thereby making the transversely oriented coil 120T sensitive to magnetic field components directed along the magnetic axis T, while having negligible sensitivity to magnetic field components parallel to T. Optionally, the flux collector 126T and / or other sections of the magnetic channel taper toward the core section 122T (eg, to facilitate efficient flux directing from its relatively wide flux collecting facets / surfaces 126F and 126B to the narrower magnetic channel 122T).

[0050] exist Figures 1A to 1E , an optional configuration of a transversely oriented coil 120T printed in a magnetic sensor 100 is illustrated. The magnetic channel 129T of the transversely oriented coil 120T is bent / folded 127 so that a section extends substantially along the printing direction to serve as the magnetic core 122T of the coil and is surrounded by conductive turns 124T, each of which is printed planarly in the print layer (e.g., the turns are substantially perpendicular to the printing direction). FIG. 2A to FIG. 4B Depictions of several other non-limiting examples of configurations of transversely oriented coils 120T whose magnetic channels 122T are bent / folded so that their several sections 122T extend substantially along (e.g., substantially parallel to) the printing direction and are surrounded by conductive turns 124T to serve as their magnetic cores 122T are provided. FIG. 2A to FIG. 4B The same reference numerals are used to designate the same Figures 1A to 1E Functionally similar elements / segments in the described transversely oriented coils.

[0051] FIG. 2A to FIG. 2DThe perspective view, side view, front view and rear view of a transversely oriented coil 120T that can be printed in a magnetic sensor 100 according to an embodiment of the present invention are illustrated respectively. In this example, the magnetic channel 129T is bent / folded 127 several times so that between the flux collectors 126T, the magnetic channel 129T is printed with / has a spiral shape, wherein a plurality of its segments 122T extend substantially along the printing direction Z and serve as the magnetic core of the coil. The plurality of segments used as the magnetic core 122T are surrounded by turns of the conductive windings 124T of the conductive channel, which are planarly printed in the printed layer with a relatively small spacing / distance between them. The turns of the conductive windings 124T of the conductive channel 128 are usually separated from each other by an electrically insulating material printed in a layer between them (for example, the electrically insulating material between the turns can be a bulk material M3 and / or optionally it can be a magnetic material M1 in some places where it is electrically insulating and will not magnetically short-circuit the flux propagation along the magnetic core). As shown, the magnetic channel 129T is formed into a spiral shape so that its multiple core segments 122T traverse the conductive winding 124T to guide the magnetic flux flowing between the flux collectors through the conductive winding 124T several times, thereby providing an improved sensitivity of the coil. Although in this non-limiting example, the magnetic channel 129T is folded so that its two core segments 122T traverse the winding 124T, it should be appreciated by those skilled in the art that the coil 120T can generally be printed with other configurations of spiral channels and can be formed with any suitable number of bends / folds 127 to produce any suitable number of core segments passing through the winding that provide optimized sensitivity for the specific sensing application for which it is used.

[0052] FIG. 3A to FIG. 3CThe side view and the front view of the magnetic channel 129 of the transversely oriented coil 120T that can be printed in the magnetic sensor 100 according to the embodiment of the present invention are respectively illustrated, and in particular a portion of the magnetic channel. In this example, between the flux collectors 126T, the magnetic channel 129T is split into a plurality of sub-magnetic channels (two in this example, 129A and 129B), each of which is bent / folded 127 several times in the form of a spiral (or other spiral shape), so that the magnetic channel 129T has a multi-spiral shape (a double spiral in this example—one spiral is formed by each of the sub-magnetic channels 129A and 129B). The magnetic print has bends / folds 127 so that its multiple segments 122T extend substantially along the printing direction Z to serve as the core segments 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 a number of winding sets 128A-128D, each winding set including a plurality of conductive turns around a different one or more of the core segments 122T. To this end, in various embodiments, the electrical contacts (at Figures 1A to 1E The electrical channel 128 between the electrical contacts 123 (shown as 123) can be printed as a single conductive path passing between the pair of electrical contacts 123 and formed to form a winding set 128A to 128D along the single conductive path, or the electrical channel 128 between the electrical contacts can be printed to be split into several (e.g., 4) sub-electrical channels (e.g., these sub-electrical channels can be connected in series with each other; for example, to maximize the induced voltage in the electrical channel 128), and each sub-electrical channel forms multiple windings / turns in one or more winding sets 128A to 128D.

[0053] As mentioned above Figures 1A to 1E As indicated, in certain embodiments of the invention, the magnetic channel 129 has a tapered shape / structure in a region thereof between the flux collecting surfaces / facets of the flux collector 126 and the magnetic core segment 122 . FIG. 3A to FIG. 3C The example illustrated in exemplifies such a tapered shape of the magnetic channel 129, wherein the cross-sectional area / width of the magnetic channel 129 narrows in a direction proceeding from the flux collecting surface / facet of the flux collector 126 toward the core section 122 of the channel. In this non-limiting example, the tapering of the magnetic channel 129 is gradually formed at several locations, including the tapering of the flux collector 126, such as Figure 3A As shown in the tapered region 121A marked in FIG. 1 , and the tapering of the magnetic channel 129 that directs the magnetic flux between the flux collectors to the core segment 122, as shown in FIG. Figure 3CThis tapering provides improved coupling of external magnetic flux from the magnetic axis T of the coil collected by the flux collector 126 to flow through the magnetic channel, and thereby improves the sensitivity of the coil. It should be noted that although in this non-limiting example, the magnetic channel tapering is illustrated for a transversely oriented coil 120T and illustrated in several tapered regions 121A and 121B, in general, the tapering of the magnetic channel towards the core segment may also be alternatively or additionally for Figure 1A The longitudinally oriented coil 120L of the sensor 100 illustrated in FIG.

[0054] Figure 4A and Figure 4B A transversely oriented coil 120T is illustrated that may be printed in a magnetic sensor 100 according to yet another embodiment of the present invention. Figure 4A depicts a perspective view of a transversely oriented coil 120T, and Figure 4B A cross-sectional view of the coil is depicted taken along plane CP. In this example the magnetic channel 129 extends in a meander-like shape / path between the flux collectors 126T. Although the flux collectors 126T are Figure 4B 126T. The magnetic channel 129 is printed with bends / folds 127 so that its multiple segments 122T extend substantially along the printing direction Z to serve as magnetic core segments 122T. Therefore, the magnetic core segments 122T are surrounded by turns of a conductive winding 124T, which includes multiple conductive turns around different one or more of the magnetic core segments 122T. To this end, in various embodiments, the electrical contacts (at Figures 1A to 1E The electrical channel 128 between the electrical contacts 123 (shown as 123) can be printed as a single conductive path passing between the pair of electrical contacts 123 and formed to form a winding set 128A to 128D along the single conductive path, or the electrical channel 128 between the electrical contacts can be printed to be split into several (e.g., 4) sub-electrical channels (e.g., these sub-electrical channels can be connected to each other, for example in series) and each sub-electrical channel forms multiple windings / turns in one or more winding sets 128A to 128D.

[0055] Return to reference Figures 1A to 1E It should be noted that the magnetic channel 122L of the longitudinally oriented coil 120L may be in the form of a rod directed along the magnetic axis L of the coil 120L (ie, along the printing / longitudinal direction Z), such as Figure 1A , Figure 1B and Figure 1D. In this case, it is not strictly necessary to print the magnetic channel 129 and / or the magnetic core 122L of the longitudinally oriented coil 120L with magnetic material M1, because in the case where the winding turns are printed planarly within the printed layer of the sensor 100, they are inherently oriented to sense / capture the magnetic flux propagating along the magnetic axis L of the longitudinally oriented coil 120L (because the printing direction is substantially parallel to the magnetic axis L of the longitudinal coil 120L). Therefore, in general, in the case where the magnetic channel / core 129 / 122L passing through the winding 124L of the longitudinally oriented coil 120L is in the form of a straight rod, the magnetic channel / core can usually be printed with magnetic material M1 and / or non-magnetic material such as ceramic or glass ceramic, or it can remain unprinted / blank (e.g., an air channel). Nevertheless, typically to facilitate the increased 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 the core segment thereof passing through the winding 124L, is typically printed with magnetic material M3 in a manner similar to that described with reference to the transversely oriented coil 120T. In addition, optionally, Figure 1B and Figure 1D As shown, to further improve the sensitivity of the longitudinally oriented coil 120L to magnetic flux from the direction of the magnetic axis L, in some embodiments, the magnetic channel 122L is printed with a corresponding pair of flux collectors 126L arranged from opposite ends thereof. The pair of optional flux collectors 126L are configured to have corresponding relatively wide / large area facets / surfaces 126U and 126D facing (e.g., perpendicular to) the magnetic axis L of the longitudinally oriented coil 120L; for example, the width / area of ​​these facets / surfaces is significantly greater than the characteristic width / cross-sectional area of ​​the core segment 122L between them (e.g., so as to guide more magnetic flux through the coil, thereby improving its sensitivity). Optionally, the flux collectors 126L taper toward the core segment 122L of the magnetic channel to facilitate efficient flux guidance between the relatively wide flux collecting facets / surfaces 126U and 126D and the narrower core segment 122T.

[0056] It should be understood that the shape of the magnetic channel 122L of the longitudinally oriented coil 120L does not have to be 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 can also be 3D printed to follow a curved / folded path within the monolithic body 110 of the sensor 100 in order to guide the magnetic flux through a higher count of turns of the conductive winding 124L surrounding the magnetic channel, and / or guide the magnetic flux through the turns of the winding multiple times. This can provide a higher sensitivity of the longitudinally oriented coil 120L.

[0057] For example, the magnetic channel 122L of the longitudinally oriented coil 120L can be bent / folded to follow / form the same pattern as described above. FIG. 2A to FIG. 4B A similar spiral path / shape or meander-like path / shape to those illustrated for transversely oriented coil 120T (e.g., only the flux collectors are arranged so that their flux collecting surfaces point perpendicular to the magnetic axis L of the longitudinally oriented coil so as to collect magnetic flux from that direction). Alternatively or additionally, in some implementations, the magnetic channel 129 of the longitudinally oriented coil 124L can be bent / folded to follow / form a coil-like path / shape (e.g., so that it is wrapped around the conductive winding 120L), such as, for example Figure 5A and Figure 5B exemplified in .

[0058] to this end, Figure 5A and Figure 5B is a schematic diagram illustrating a longitudinally oriented coil 120L that is 3D printed in the sensor 100 such that its magnetic channel 129 is bent / folded to form a coiled path / shape of its magnetic core 122L, wound around a conductive winding 124L. Figure 5A and 5B The same reference numerals are used to designate the same Figures 1A to 1E Functionally similar elements / segments / parts in the described longitudinally oriented coils.

[0059] Figure 5A depicts a perspective view of a coil 120L including a flux collector 126L, and Figure 5B Another perspective view of coil 120L is depicted without flux collectors 126L, so that the internal configuration of coiled magnetic core 122L and its winding around conductive winding 124L is visible in this figure. To this end, magnetic flux collected by one of flux collectors 126L is directed by magnetic channel 129 to encircle the conductive turns of winding 124T, typically several times. For example, from Figure 5A Magnetic flux collected by the top flux collecting surface 126U illustrated in FIG. 1 is directed through the magnetic channel 129 from region 125 of the magnetic channel 129 (which is the connection between the flux collector and the coiled magnetic core 122L) to sequentially follow through the coiled segments C1 to C8 and then exit the coil through the bottom flux collecting surface 126D. The direction of flux flow through the coiled core segments C1 to C8 of the magnetic core 122L is depicted. To this end, the coiled core segments C1 to C8 are wound / wrapped around (e.g., wound with) the turns of the conductive winding 124T in response to the magnetic flux propagating through the coiled core segments C1 to C8 to induce a voltage / current in the conductive winding 124T and thereby induce a voltage at the electrical contacts 123.

[0060] It should be noted that in this non-limiting example, in order to provide further improved sensitivity of the coil, the conductive winding includes a plurality of turns 124S stacked along the printing direction Z in a plurality of printed layers (e.g., with relatively small spacing therebetween along the printing direction Z), wherein in at least some of these printed layers, a plurality of turns 124C are printed concentrically so as to provide further improved sensitivity of the coil.

[0061] To this end, the above Figures 1A to 5B Various non-limiting examples of a multi-axis 3D printed magnetic field sensor 100 are schematically illustrated, which includes at least one coil 120L whose magnetic axis L is longitudinally oriented along a printing direction Z of the sensor (the direction along which printed layers are deposited one upon another) and at least one coil 120T whose magnetic axis T is oriented transversely to (e.g., perpendicular to) the printing direction Z.

[0062] Preferably, in both the longitudinally oriented coil 120L and the transversely oriented coil 120T, the turns of the conductive winding 124 are 3D printed within the printed layers so as to utilize the smaller spacing between the printed layers (which is less than the minimum feature size / width within the layer) to encapsulate / print a higher count of conductive winding turns in the coil, and facilitate high sensitivity of the sensor (i.e., facilitate high induced voltage in response to magnetic field sensing). To achieve this, for the transversely oriented coil 120T whose magnetic axis T is generally perpendicular / crossed to the printing direction, its magnetic channel 129 is printed with a pair of flux collectors 126T facing the magnetic axis T to collect flux propagating therefrom, and further printed with a turn / fold / bend 127 between the pair of flux collectors 126T so that a portion thereof extends along the printing direction Z and passes through the conductive winding 124TL to serve as its magnetic core 122T, which guides magnetic flux through it. In the non-limiting embodiment specifically illustrated herein, the magnetic channel 129 of the transversely oriented coil 120T is illustrated as having a stretched "Z" shape ( Figure 1A , Figure 1C and Figure 1E ), with a spiral shape ( FIG. 2A to FIG. 3B ) and / or have a meander-like shape ( Figure 4A and Figure 4B However, it should be understood and will be easily appreciated by those skilled in the art that the transversely oriented coil 120T according to the present invention may also be formed to have other magnetic channel 129 shapes, for example, through appropriate adaptation, it may be implemented as a coiled shape with a magnetic core, such as in Figure 5A and Figure 5B As for the longitudinal coil 120T, their magnetic paths can pass through the plane of the coil / winding turns 124T printed later, while being formed into a straight rod-shaped magnetic core (e.g., as shown in FIG. 1 ) along the printing direction Z. Figure 1A , Figure 1B and Figure 1D Nevertheless, in some embodiments, it may be preferred to also print the magnetic channels of the longitudinally oriented coils 120L with more complex shapes, such as Figure 5A and Figure 5B In this regard, it should be understood and will be readily appreciated by those skilled in the art that the longitudinally oriented coil 120L according to the present invention may also be formed to have other magnetic channel 129 shapes, such as, by appropriate adaptation, a meander or spiral shape having a magnetic core, such as FIG. 2A to FIG. 4B As illustrated in .

[0063] Furthermore, it should be noted that some of the optional properties of the 3D printed coils, which are only exemplified in some of the above embodiments, 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, not just in those embodiments in which they are described above:

[0064] -like FIG. 3A to FIG. 3C As illustrated in FIG. 1 , the magnetic channel 129 is split to form multiple sub-magnetic channels thereof between the flux collectors.

[0065] -like FIG. 3A to FIG. 3C As exemplified in , splitting the electrical channel to form a plurality of conductive paths and optionally a plurality of winding sets; and

[0066] - forming a stack of turns in a plurality of layers and forming an electrically conductive winding of concentric turns in each or at least some of these layers.

[0067] Typically, one or more or all of the coils 120 of the sensor 100 are designed to have an open magnetic circuit configuration, which is suitable for accurate sensing of magnetic fields and is particularly suitable 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 to refer to a coil structure with an open-ended magnetic channel that does not substantially shield or shunt an external magnetic field, thereby allowing the external magnetic field to pass through the magnetic core of the coil.

[0068] As noted above, the 3D printed magnetic field sensor 100 of the present invention as described above, particularly when printed with a coil 120 having an open magnetic circuit configuration, may be suitable for use as a position and / or force sensor in a medical device / equipment requiring a position and / or force sensor. FIG. 6A to FIG. 6C, these figures illustrate an example of a medical device 1000 (e.g., a probe / catheter) according to an embodiment of the present invention, which is equipped with a magnetic field sensor 100 configured and operable as a five-axis position sensor (3D spatial position, pitch and yaw) according to an embodiment of the present invention. Fig. 6A is a side view of a medical device 1000 equipped with a magnetic field (position) sensor 100, and Figure 6B and Figure 6C are two perspective views illustrating the internal structure (6B) and the configuration of the flux collector (6C) of a magnetic field sensor 100 configured / fabricated in accordance with an embodiment of the present invention.

[0069] For this purpose, refer to Fig. 6A In this non-limiting example, a medical device 1000 includes a housing H having a longitudinal axis Z, in which a five-axis magnetic field-based position sensor 100 is provided. In this example, the magnetic field-based position sensor 100 is provided so that the longitudinal axis Z of the housing is along the same direction as the printing 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 from along 5 axes, including three spaced longitudinal axes L1 to L3 parallel to the longitudinal axis Z of the housing, and two transverse axes T1 and T2 that are not parallel to each other and to the longitudinal axis Z of the housing.

[0070] The medical device 1000 and one or more external magnetic field sources MF L In association, the one or more external magnetic field sources generate reference magnetic fields, the amplitude and / or phase of which provide a reference system for determining the position and / or orientation of the medical device 1000 relative thereto. L The generated reference magnetic field can be measured along three axes by the magnetic field-based position sensor 100 of the medical device 100 to determine the position of the medical device 100 relative to the external magnetic field source MF. L 3D spatial position and / or orientation. To achieve this, in this embodiment, the magnetic field-based position sensor 100 includes at least one longitudinal orientation coil 120L.1 and at least two transverse orientation coils 120T.1 and 120T.2, whose respective magnetic axes L1, T1 and T2 are not parallel to each other and span three dimensions. The at least one longitudinal orientation coil 120L.1 and the at least two transverse orientation coils 120T.1 and 120T.2 are typically printed with an open magnetic circuit configuration to sense the magnetic field generated by an external magnetic field source MF with improved sensitivity. L Therefore, the three coils 120L.1, 120T.1 and 120T.2 facilitate the measurement of the magnetic field generated by the external magnetic field source MF LThe different vector components of the magnetic field generated by the external magnetic field source MF are facilitated by such measurement, as will be readily appreciated by those skilled in the art. L The position and orientation of the medical device 1000 is determined by the reference frame defined by the magnetic field.

[0071] In one embodiment, the housing H of the medical device includes a main section M and an end section T connected to each other via a band coupler J such as a spring or a joint, and the band coupler is configured to facilitate bending of the end section T relative to the orientation of the main section M relative to the longitudinal axis Z of the housing H under the action of an applied force F (for example, a force that can be applied when the end section T of the medical device contacts the patient's body tissue).

[0072] The medical device 1000 internally includes a magnetic field source MF that provides a reference magnetic field. O , which reference magnetic field facilitates measurement of the degree of curvature between the tip T and the main section M by the magnetic field-based position sensor 100. In general, the degree of curvature indicates the magnitude and / or direction of a force F applied to the tip section T (e.g., between the tip and the patient's body tissue). In order to measure the magnitude and direction of the force F applied by the tip T to the tissue, the medical device 1000 includes a magnetic field source MF O (e.g., magnetic field generating coils with associated power delivery circuitry) and magnetic field based positioning sensors 100 such that they are arranged therein from opposite sides of joint J (typically, internal magnetic field source MF O The internal magnetic field source MF is arranged in the terminal section T and the magnetic field based positioning sensor 100 is arranged in the main section M, but the opposite arrangement is also applicable). O The magnetic field based positioning sensor 100 includes a unitary body 110 having a plurality of at least three longitudinally oriented coils 120.1, 120.2 and 120.3, such as those described above with reference to Figures 1A to 5B As illustrated, these longitudinally oriented coils are 3D printed in a monolithic body according to the techniques of the present invention, wherein their respective magnetic axes L1 to L3 are parallel to the longitudinal axis Z of the housing (also the printing direction of the sensor 100). The three longitudinally oriented coils 120.1, 120.2 and 120.3 are typically printed with an open magnetic circuit configuration and are suitable for sensing the magnetic field generated by the internal magnetic field source MF with increased sensitivity. O As will be appreciated by those skilled in the art, since the magnetic axes L1 to L3 of the three longitudinally oriented coils 120.1, 120.2 and 120.3 are collinear / parallel to each other and to the longitudinal axis L of the housing H and are not located on a common plane (not coplanar), the magnetic field generated by the internal magnetic field source MF OThe measured magnetic field (eg, its magnitude measured by each of these coils) indicates the relationship between the magnetic field position sensor 100 and the internal magnetic field source MF. O To this end, considering the technology of the present invention, a person skilled in the art will easily understand how to adjust the relative orientation of the two orientation axes (such as pitch and yaw) between the internal magnetic field source MF based on the three longitudinal orientation coils 120.1, 120.2 and 120.3. O The generated magnetic field is measured to determine the relative magnetic field of the sensor 100 to the source MF. O Furthermore, one of ordinary skill in the art will readily appreciate how the force vector F applied to the tissue may be determined based on this measured orientation of the sensor 100 and the properties of the ribbon coupler J (eg, spring constant).

[0073] Thus, in this non-limiting example, the magnetic field sensor 100 is designated to sense its relative to the external magnetic field source MF L The position and orientation of the magnetic field relative to the internal magnetic field source MF O orientation. Thus, the magnetic field sensor is configured as a five-axis magnetic field sensor capable of measuring magnetic fields from the aligned three longitudinal axes L1 to L3 and the two transverse axes T1 and T2. However, it should be noted that the present invention is not limited to a five-axis configuration of the magnetic field / positioning sensor 100 and can also be used to implement a magnetic field / positioning sensor 100 with two sensing axes, three sensing axes or four sensing axes and / or with any other desired number of sensing axes. For example:

[0074] - Three-axis magnetic sensor - used to measure the 3D position / orientation of a medical device relative to an external magnetic field (3-axis sensor);

[0075] - Two-axis magnetic sensor - used to measure the 2D position / orientation of a medical device relative to an external magnetic field;

[0076] - Two-axis sensor - used to measure one orientation angle of the sensor relative to the internal magnetic field (e.g., pitch or yaw);

[0077] - Three-axis or four-axis magnetic sensors—used to measure one orientation angle of the sensor relative to an internal magnetic field (e.g., pitch or yaw) and the 2D or 3D position / orientation of the medical device relative to an external magnetic field, respectively; and

[0078] - A five-axis magnetic sensor, as in this example—used to measure two orientation angles of the sensor relative to an internal magnetic field (e.g., pitch and yaw) and the 3D position / orientation of the medical device relative to an external magnetic field.

[0079] In this regard, it should be noted that, in view of the description herein, after understanding the present invention, a person of ordinary skill in the art will easily appreciate how to manufacture, by 3D printing, magnetic field sensors having any suitable number of coils and various configurations / orientations of their magnetic axes relative to the printing direction Z, so as to accurately / sensitively measure the position and / or orientation of the sensor relative to one or more magnetic field sources in one, two and / or three dimensions.

[0080] exist Figure 6B and Figure 6C 2 is a perspective view illustrating in more detail the configuration of the five-axis magnetic field sensor 100 according to the embodiment of the present invention incorporated in the above-mentioned medical device 1000. Figure 6B is a perspective view of the magnetic field sensor 100, depicting the internal structure / coils of the five-axis magnetic field sensor 100, wherein its integral body 110 is depicted only by dot-dashed outline lines (the bulk material M3 from which it is printed is not shown so as not to obscure the configuration of the coils 120 of the 3D printed sensor). Figure 6C 1 is another perspective view of a five-axis magnetic field sensor 100, illustrating the arrangement of some of the flux collectors 126 of the coils of the sensor 100. The magnetic field sensor 100 in this example is illustrated by referring to FIG. Figures 1A to 5B The 3D printing technology of the present invention is manufactured and includes three longitudinally oriented coils 120L.1 to 120L.3 having corresponding parallel magnetic axes L1 to L3 pointing along the longitudinal / printing direction Z and two transversely oriented coils 120T.1 and 120T.2 having corresponding non-parallel magnetic axes T1 and T2 pointing in two transverse directions.

[0081] The three longitudinal orientation coils 120L are co-aligned so that their respective magnetic axes are parallel to each other. This arrangement of the longitudinal orientation coils 120L facilitates the use of the magnetic signals sensed / obtained thereby to determine the magnetic field sensor 100 relative to the longitudinal direction Z relative to an internal magnetic field source MF located in front of the magnetic field sensor 100. O Additionally, since the magnetic axes T1 and T2 of the two transverse orientation coils 120T and the magnetic axis, for example, L1, of the at least one longitudinal orientation coil 120L span the 3D coordinate, the magnetic signals sensed / obtained from the two transverse orientation coils 120T and the at least one longitudinal orientation coil 120L can be utilized / processed to determine the relative magnetic field of the sensor to the external magnetic field source MF. L The magnetic field provides the position (e.g., location and / or orientation) of a reference coordinate system.

[0082] In this example, the magnetic field sensor 100 has an elongated tubular / cylindrical shape, elongated about a longitudinal / printing axis Z, and 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 accordingly the width / diameter W of the magnetic field sensor 100, may be approximately 2 mm.

[0083] In some embodiments, to facilitate compact arrangement of coils 120L.1 to 120L.3 and 120T.1 and 120T.2 within narrow monolithic body 110, three longitudinally oriented coils 120L.1 to 120L.3 are arranged in respective three angular sectors around longitudinal / printing axis Z, and two transversely oriented coils 120T.1 and 120T.2 are arranged in respective two angular sectors around the axis. Preferably, in some embodiments, three longitudinally oriented coils 120L.1 to 120L.3 are equally spaced (e.g., forming an equilateral triangle) so as to provide a uniform distribution of the magnetic field from internal magnetic field source MF. O Equally "weighted" magnetic field signals are obtained. For example, in the present non-limiting example, the three longitudinally oriented coils 120L.1 to 120L.3 are equiangularly spaced apart 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 apart relative to the longitudinal / printing axis Z and oriented relative to each other at an angle that is preferably relatively close to 90° (e.g., within a range of tens of degrees from 90°), so that the magnetic signals read therefrom can be used / processed to identify / determine two perpendicular vector components of the magnetic field sensed thereby with a high SNR (e.g., without much overlap between the vector components of the individually sensed magnetic fields). However, typically, the relative angular spacing between the transversely oriented coils 120T.1 and 120T.2 is further optimized to facilitate compact arrangement of the coils 120 of the sensor in a monolithic body or other features thereof.

[0084] For example, in the illustrated embodiment, for example, Figure 6B , the transversely oriented coils 120T.1 and 120T.2 and their magnetic axes T1 and T2 are angularly spaced / oriented relative to each other around the longitudinal / printing axis Z through an angle of 120°, which in this case (with this configuration / size / shape of the coils) facilitates a compact arrangement of coils with relatively high sensitivity within the limited maximum dimensions of the sensor 100 for assembly in the medical device 100.

[0085] To this end, in some embodiments, compact size of the sensor and high quality position signal sensing (e.g., sensing of substantially equally weighted vector components of the desired magnetic field) are achieved by arranging the five coils 120L.1 to 120L.3 and 120T.1 and 120T.2 in five respective angular sectors at the same level / elevation relative to the Z axis. Alternatively, in some embodiments (not specifically shown in the figures), compact size of the sensor and high quality position signal sensing are best achieved by arranging the three longitudinally oriented coils 120L.1 to 120L.3 at an angular sector in one level / elevation relative to the longitudinal / printing Z axis, and arranging the two transversely oriented coils 120T.1 and 120T.2 in two angular sectors at another level / elevation relative to the longitudinal / printing Z axis.

[0086] As illustrated in this non-limiting example, the magnetic field sensor 100 has an annular shape including an aperture 115 fabricated (not printed) through its monolithic body 115 along a longitudinal axis Z so as to enable some components of the medical device 100 (such as electrical / signal lines and / or fluid lines of a catheter) to pass through the aperture. To this end, in the case of such an elongated shape of the sensor 100, the maximum distance D between the pair of opposing flux collectors 126T is severely limited. For example, in a sensor having an annular shape with a width W of about 2 mm, wherein each of the transversely oriented coils 120T includes a flux collector 126T proximate an outer facet of the annular shape and a flux collector 126T positioned proximate an inner facet of the annular shape facing the aperture 115, as shown, the maximum distance D between the opposing flux collectors 126T along the magnetic axis T of the transversely oriented coil 120T is limited to substantially less than 1 mm (e.g., typically limited to only about 0.5 mm, considering that the aperture 115 has a radius of typically about 1 mm or less). Therefore, with such a short distance along the magnetic axis T of the transversely oriented coil, it is not practical to use current conventional 3D printing techniques to manufacture a transversely oriented coil 120T with a straight / rod magnetic core that will provide sufficient sensitivity suitable for medical device positioning. This problem is overcome by the present invention's techniques by printing the magnetic core of the transversely oriented coil 120T so that it includes a bent / folded magnetic channel 122T between flux collectors 126T within the monolithic body 110 of the sensor 100, so that the magnetic channel has an extended length (e.g., greater than the distance between the flux collectors 126T), thereby facilitating 3D printing of a higher count of conductive windings 124T around the magnetic channel 122T (compared to the case of a shortened rod core), which in turn improves the sensitivity of the transversely oriented coil 120T of the sensor (despite its elongated shape).

[0087] refer to FIG. 6D to FIG. 6F, illustrates an embodiment of a sensor 100 that is configured to facilitate robust, reliable, and cost-effective connection of a signal line 159 to a coil 120 of the sensor before / during assembly of the sensor's unitary body 110 to a medical device 1000. In this embodiment, the sensor 100 includes Fig. 6A is exemplified as optional and in Fig. 6E and Fig. 6F The signal connector 150 illustrated in detail in FIG. 1 and its 3D printed monolithic body 110 having a plurality of coils 120 (including transversely and longitudinally oriented coils 120T and 120L) 3D printed therein. Fig.6D As illustrated in FIG. 1 , the electrical contacts / terminals 123 of the coils 120 are exposed from the monolithic body 110 at a surface (typically a flat surface) of the monolithic body. In this example, there are 10 electrical contacts / terminals 123, two for each of the five coils 120 arranged in a predetermined arrangement. Fig. 6E and Fig. 6F The signal connector 150 illustrated in FIG. 1 includes a signal connector 150 from its rear side ( Fig. 6E ) has a complementary arrangement of electrical contact pads 153 that mates with the arrangement of electrical contacts / terminals 123 in the unitary body 110. The rear side ( Fig. 6F ) is electrically coupled to solder contacts 154 at the front side 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 lines 159 (typically shielded signal lines such as twisted pairs) is typically electrically connected to the solder contacts 154 by soldering / wire bonding. More specifically, in this example, there are five twisted pairs (only two twisted pairs are shown in the figure for clarity), each twisted pair being soldered to a corresponding pair of solder contacts 154 electrically coupled to the electrical contact pads 153 (via RDLs / through holes), which are arranged in the rear side of the signal connector 150 to contact the electrical contacts / terminals 123 of one of the coils 120 in the monolithic body 110.

[0088] In some embodiments, optionally, the signal connector 150 includes a fixing area 155 on its front side to which the signal cable 158 can be attached (e.g., glued) to improve the robustness and reliability of its electrical connection with the solder contacts 154 of the signal connector 150 (e.g., so that they can reliably withstand stress / strain that may be applied thereto during assembly of the sensor 100 within the confined space of the medical device 1000).

[0089] To this end, during assembly of the sensor 100 in the medical device 1000, for example before or after the integral body 110 is inserted into the device 1000, the signal connector 150 can be attached to the integral body 110 such that the electrical contact pads 153 at the rear side of the signal connector 150 are electrically connected to the complementary arrangement of electrical contacts / terminals 123 of one of the coils 120 in the integral body 110 (as will be appreciated by those skilled in the art, this can be reliably performed using soldering, for example using flip-chip bonding).

[0090] In some embodiments, such as for example FIG. 6D to FIG. 6F As illustrated in FIG. 1 , the integral body 110 of the sensor 100 and the signal connector 150 include complementary grooves 102 and recesses 152, respectively, which are arranged so that the grooves and recesses are aligned when the signal connector 150 is properly coupled to the integral body 110 (wherein the electrical contact pads 153 properly contact the corresponding electrical contacts / terminals 123). Considering the miniature size of the sensor 100 in some specific implementations, the grooves 102 and recesses 152 facilitate accurate and easy alignment between the integral body 110 of the sensor 100 and the signal connector 150 when they are assembled / coupled together, so that the electrical contact pads 153 are properly coupled to the corresponding electrical contacts / terminals 123. Alternatively or additionally, in some embodiments, when the sensor 100 is deployed in a medical device 1000, the groove 102 and the recess 152 provide for passing the signal / power line through the narrow housing H of the medical device 1000 toward a distal section of the medical device (e.g., to deliver power to an internal magnetic field source MF). O ) passage.

[0091] It should be noted that in some specific implementations of the magnetic field / positioning sensor 100 described with respect to all of the above embodiments, the conductive material M2 used in the 3D printing of the electrical channel 128 of the coil 120 includes silver. Alternatively or additionally, in some embodiments, the conductive material M2 may include copper, silver, palladium and / or a silver-palladium alloy. The magnetic material M1 used for the magnetic channel 129 of the 3D printed coil 120 (i.e., their magnetic core 122 and flux collecting pole 126) may typically include a ceramic ferrite material and / or a metal material. In some embodiments, the magnetic material M1 is a material having a relative magnetic permeability μ of at least 100 or more. r Preferably, the magnetic material M1, especially the magnetic material used for printing the magnetic channel 129 of the transverse orientation coil 120T, has a relative magnetic permeability μ of about 5000 or more. r (In some implementations, the folded / curved magnetic channel has a relatively small cross-section, and thus requires a relatively high magnetic permeability μ of about 5000 or more. r, so as to control / facilitate funneling of the magnetic field flux passing therethrough with sufficiently small losses). This is to facilitate efficient guidance of the magnetic flux through the folded / curved magnetic channel of the transversely oriented coil 120T. The non-magnetic dielectric material M3 (also referred to herein as the bulk material) may, for example, include ceramics and / or glass ceramics. Preferably, in some embodiments, the conductive material M2 of the conductive channel 128 is printed so that it is completely embedded in the bulk of the monolithic body 110 so as to be isolated from environmental conditions that may degrade it. In some embodiments, optionally, the electrical contacts / terminals of the conductive channel are also 3D printed and embedded in the bulk, and are only exposed to the outside (e.g., by polishing) after the 3D printed sensor is sintered / fired.

[0092] As noted above, and as exemplified in all of the above-described embodiments, the magnetic field / positioning sensor 100 of the present invention is manufactured by 3D printing of at least three different 3D printable materials M1 to M3. Figure 7 is a flow chart of a method 200 for manufacturing the magnetic field sensor 100 described above by 3D printing technology according to some embodiments of the present invention.

[0093] In operation 210 of method 200, one or more magnetic field sensors 100 of the present invention (such as those described above with reference to FIG. 1 ) to be 3D printed are provided. Figures 1A to 6F 100). The model indicates the 3D spatial distribution (voxel map) of at least three materials M1 to M3 to be 3D printed to manufacture the magnetic field sensor 100 of the present invention. Specifically, the model indicates the corresponding spatial distribution of the three materials M1 to M3 that should be 3D printed to form the magnetic field sensor 100 according to the present invention. More specifically, the spatial distribution of the three materials M1 to M3 is such that 3D printing produces a magnetic field sensor 100 having a monolithic body 110 including one or more longitudinally oriented coils 120L and one or more transversely oriented coils 120T printed therein.

[0094] Typically, the multi-material 3D printing used operates by printing layers successively one above the other along the printing direction Z. Each layer may include one, two or all three materials. The spatial distribution of the three materials M1 to M3 in the model used for printing is such that the printing result has a plurality of coils 120 defined by the distribution of the three materials M1 to M3 within the monolithic body 110, and such that the block of the monolithic body is 3D printed with the non-magnetic non-conductive material M1, and the plurality of coils 120 therein include:

[0095] one or more longitudinally oriented coils 120L, their respective magnetic axes (L) being oriented substantially parallel to the printing direction Z and each comprising conductive windings 124L comprising an arrangement of conductive turns planarly 3D printed in a plurality of 3D printed layers with a conductive material M2; and

[0096] - One or more transversely oriented coils 120T, whose respective magnetic axes (T) are oriented substantially transverse / perpendicular to the printing direction Z. Each transversely oriented coil 120T comprises a magnetic channel 129 3D printed with a magnetic material M1, such that the magnetic channel 129 comprises at least one pair of opposing flux collectors 126T having respective relatively large facets perpendicular to its transversely oriented magnetic axis (T). The magnetic channel 129 of the transversely oriented coil 120T is printed with one or more bends / folds 127 within the monolithic body 110, such that one or more sections 122T thereof extend substantially along the printing direction Z to serve as a magnetic core of the coil, and the transversely oriented coil 120T comprises a conductive winding 124T having an arrangement of conductive turns planarly 3D printed in a plurality of 3D printed layers with a conductive material M2, such that they surround the magnetic core 122T.

[0097] The spatial distribution of the three materials M1 to M3 in the model may also define other features of the sensor 100 described above, for example: magnetic channels for longitudinally oriented coils 129 may also be manufactured; the magnetic channels 129 for longitudinally and / or transversely oriented coils may be formed into various other more complex shapes, such as FIG. 2A to FIG. 5B As described in; the conductive windings of the coil can typically be 3D printed as part of an electrical channel 128, which is terminated by two or more electrical contacts / terminals 123 at the surface of the monolithic body 110; and the monolithic body 110 can be formed into an elongated / tubular shape and / or a cylindrical and / or an annular shape with a hole 115, or other body geometries adapted to a specific catheter.

[0098] In operation 220 of 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 to M3 in the model. Multi-material 3D printing can be performed, for example, by using photopolymerization 3D printing technology to print a layer consisting of a combination of several materials with different electromagnetic properties (for example, two, three, or optionally more than three materials with different electromagnetic properties can be printed in each layer). In a typical example, the 3D printing of the magnetic field sensor 100 described above involves the printing of the spatial distribution of at least three materials with different electromagnetic properties, including: a conductive material M2, used for 3D printing of an electrical channel 128 of a coil 120; a magnetic material M1, used for 3D printing of a magnetic channel 129 of the coil 120; and a non-magnetic dielectric material M3, used for 3D printing of a block of a monolithic body 110 of the sensor 100.

[0099] To this end, in various embodiments, the conductive material M2 may include, for example, silver and / or copper and / or palladium and / or a silver-palladium alloy. The magnetic material M1 may include, for example, a ceramic-ferrite material and / or a metal material. In some embodiments, the magnetic material M1 is a material having a relative magnetic permeability μ of at least 100 or more. r Preferably, the magnetic material M1, especially the magnetic material used for printing the magnetic channel 129 of the transverse orientation coil 120T, has a relative magnetic permeability μ of about 5000 or more. r The non-magnetic dielectric material M3 (also referred to herein as bulk material) may include, for example, ceramic and / or glass ceramic.

[0100] 3D printing of the sensor 100 can be implemented, for example, based on the principle of Vat photopolymerization, using, for example, stereolithography (SLA) or digital light processing (DLP) for pattern implementation / projection. The present invention is not limited to these specific technologies and can generally be implemented by other multi-material 3D printing technologies, such as can be developed to be suitable for the manufacture of electrical components according to the present invention.

[0101] Using the technology of the present invention, a magnetic field sensor 100 with a small feature size can be printed using a 3D printed layer having the following characteristics: the 3D printed layer has a thickness as low as the micron level (for example, the sintered layer thickness can be about 8 to 10 microns) and has intra-layer features with characteristic sintered sizes ranging from about 24 to 50 microns or less (this takes into account that the pixels within the layer can be printed at a pitch / width of about 12 to 25 microns, and that each important / functional feature is preferably printed with a width of at least two pixels to avoid failures due to erroneous printing of a single pixel).

[0102] In order to perform 3D printing, curable resins corresponding to at least three materials M1, M2 and M3 are provided. More specifically, the curable resin used in 3D printing of the magnetic field sensor 100 according to the present invention includes at least the following:

[0103] - A magnetic material resin comprising particles of a magnetic material M1 soft magnetic material suspended in a curable polymer binder. The particles of the magnetic material M1 may include, for example, particles of a ceramic-ferrite material. It should be noted that in some embodiments, the particles of the magnetic material M1 may alternatively include particles of a magnetic metal material, such as an iron alloy, an iron-silicon alloy, an iron-aluminum-silicon alloy, a low-carbon steel, a nickel-iron alloy, an iron-cobalt alloy, a ferrite, an amorphous alloy, and in some cases a nickel-cobalt alloy (particularly in the case where it has a soft magnetic quality). In embodiments in which a microcoil is manufactured within a monolithic body 110, particularly in embodiments in which the magnetic channel 129 of the coil exhibits fine features, the particles of the magnetic material used may be provided, for example, with a characteristic size of micrometer to submicrometer scale.

[0104] - A conductive material resin comprising particles of a conductive material M2 suspended in a curable polymer binder. The particles of the conductive material M2 may, for example, comprise a silver material, a copper material and / or a silver-palladium alloy. The specific selection of a suitable conductive material generally depends on the required temperature of the sintering / firing process required to complete the printing of the electronic component, and therefore on the type of magnetic material and dielectric material. In an embodiment in which a microcoil is manufactured within a monolithic body 110, the particles of the conductive material M2 used in printing may have a characteristic size ranging from micron to submicron scale and as small as nanometer scale.

[0105] - 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 which can withstand the high sintering / firing temperatures required to sinter the printed magnetic and conductive materials M1 and M2. Also here, the size of the particles can be selected according to the minimum feature size that should be occupied by the dielectric material / volume of the magnetic field sensor and, for the manufacture of micro coils, can be selected, for example, on a nanometer to micrometer scale.

[0106] Regarding the material selection in the above text, 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 preferred to print the magnetic channel with an electrically insulating ceramic ferrite. One reason for this is that the use of ceramic ferrites helps to achieve a more compact arrangement of the magnetic channel and the electrical channels 129 and 128. This is because the soft magnetic metal materials (non-ceramic ferrites) suitable for magnetic channel printing are generally conductive. Therefore, the magnetic channel 129 printed with non-ceramic ferrites 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. Therefore, in some embodiments, it is preferred to use a ceramic ferrite material to print the magnetic channel 129.

[0107] Thus, using the above-mentioned at least three curable resins, 3D printing of the magnetic field sensor 100 can be performed layer by layer along the printing direction Z using, for example, a photopolymerization multi-sided 3D printing technology such as SLA or DLP. The printing direction Z is typically selected so that it is substantially perpendicular to the plane spanned by the turns of the conductive windings 124 of the coil 120. For this reason, as noted above, the selection of the printing direction Z can be particularly important in the printing of the miniature magnetic field sensor 100, because the lateral feature resolution of the print in the XY plane is lower than the “vertical” resolution of the layer obtained along the printing direction Z.

[0108] To this end, in general, 3D printing of each layer of the sensor 100 typically includes the following (not necessarily in this order):

[0109] - depositing / printing and curing magnetic material M1 at the area of ​​the layer corresponding to the magnetic channel 129 of the coil 120;

[0110] - depositing / printing and curing a conductive material M2 at the area of ​​the layer corresponding to the electrical path 128 of the coil 120; and

[0111] - Deposition / printing and curing of non-conductive (dielectric) non-magnetic material M3 to form the bulk of the monolithic body 110 of the sensor 100 .

[0112] It should be noted that in some embodiments, 3D printing is performed such that the conductive material M2 is fully embedded within the bulk of the monolithic body 110 in order to protect the conductive material M2 from degradation (e.g., oxidation) due to environmental conditions, particularly during high temperature sintering 230 following layer-by-layer material deposition and curing.

[0113] Therefore, by continuously printing and curing consecutive layers according to the spatial distribution of the material in the sensor model in operation 220, one or more 3D structures of one or more sensors 100 are obtained, each 3D structure including at least one longitudinally oriented coil and at least one transversely oriented coil electrical coil 220.

[0114] The method 200 also 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 drive off polymers (binding polymers) from the one or more magnetic field sensors 100 and to fire ceramic or glass ceramic materials such as M3 and optionally M1 used in printing. To this end, the material density of the printed ceramic and metal materials (e.g., M1, M2, and M3) of the magnetic field sensor 100 after sintering is close to 100%. For example, in an embodiment in which the conductive material M2 mainly includes silver, sintering can be performed at a temperature below the melting point of silver (e.g., at a temperature not exceeding 961°C; preferably, in this case, the sintering temperature can be limited to up to about 900°C to achieve a stable sintering process). In other embodiments in which the conductive material includes a silver-palladium alloy, sintering can be performed at a temperature below the melting point of the alloy (the specific melting point depends on the ratio of silver to palladium in the alloy and depends on the composition, and the melting point is generally between the melting point of silver, 961°C, and the melting point of palladium, 1,555°C). In another example, in an embodiment where the conductive material M2 comprises copper, sintering may be performed in an oxygen-deficient environment (to avoid oxidation of the copper) and at a temperature below the melting point of copper, 1084°C.

[0115] In this regard, it should be noted that in some embodiments of the present invention, method 200 is performed for 3D printing a magnetic field / positioning sensor 100 in which a miniature electrical coil having features of micrometer-scale size is embedded. For example, depending on the specific model design and 3D printing technology used, the 3D printed layer can be printed with a sintered thickness in the range of about 5 μm to 15 μm (e.g., 9 μm). Therefore, the pitch of the turns of the winding 124 (which can be about twice the pitch of the 3D printed layer) can be in the range of about 10 μm to 30 μm sintered along the printing direction Z of the 3D printed sintered layer (e.g., typically the thickness of the layer is about 9 μm and the pitch of the turns between the layers is about 18 μm).

[0116] Additionally, optionally (depending on the particular printing technology used), method 200 may include a method for removing printed sensor 100 from a build / 3D printing platform (e.g., Figure 1E201) separation operation 240. Generally speaking, depending on the type of build platform (e.g., and whether it can withstand sintering 230), operation 240 can be performed before or after sintering 230. In fact, in some embodiments of the present invention, especially in the case of printing a micro / fine sensor that may be damaged by performing separation from the build platform before sintering, a suitable build platform that can withstand the temperature of sintering 230 can be used, and the separation of the sensor from the platform can be performed after sintering in order to avoid / reduce damage to the sensor during the separation process.

[0117] In view of the above, the method 200 of the present invention provides a novel and inventive technique for manufacturing a magnetic field / positioning sensor 100 including a plurality of coils 120 as described above. The method 100 is suitable for manufacturing micro sensors 100 having feature sizes as small as a few microns, and can be used in mass production to simultaneously 3D print a large number of such micro sensors 100 built on the same platform at the same time (e.g., hundreds to thousands can be printed using, for example, VAT photopolymerization techniques). Each magnetic field / positioning sensor 100 may have, for example, a ceramic / glass ceramic body 110 in which a highly sensitive open magnetic circuit coil is embedded arranged in a transverse and longitudinal orientation relative to the printing direction Z. The micro magnetic field / positioning sensor 100 can be manufactured to have small dimensions, such as a width of about 2 mm and a height of about several millimeters, wherein the coil 120 has a small size of about 0.5 mm to 4 mm and provides a high sensitivity / induced voltage in response to a magnetic field, such as in the range of 0.1 to 1 μV / (Gauss*Hz).

[0118] It should be noted that Figures 1A to 6F The illustration of the magnetic field / positioning sensor 100 in FIG. 1 is provided for illustration purposes only and is not necessarily drawn to scale or in proper proportion. For example, in general, the count of windings in the coils 120 according to the present invention can be substantially higher than that illustrated in the figure. In addition, the specific shapes illustrated for the coils 120, such as the specific shapes of their magnetic cores 122, windings 124, and flux collectors 126 are provided only as examples, and in practice may have other shapes and / or aspect ratios different from those illustrated without departing from the scope of the present invention.

[0119] Example

[0120] Embodiment 1. A magnetic field sensor, comprising:

[0121] A monolithic body having a plurality of coils defined therein by 3D printing successive print layers along a print direction; the plurality of coils comprising:

[0122] - one or more longitudinally oriented coils having respective first magnetic axes oriented substantially parallel to the printing direction; each of the longitudinally oriented coils comprising a 3D printed first conductive path forming an arrangement of first conductive windings having turns in the plane of the printed layer; and

[0123] - the plurality of coils further comprises one or more transversely oriented coils having respective second magnetic axes oriented transversely with respect to the printing direction.

[0124] Embodiment 2. A magnetic field sensor according to embodiment 1, wherein each of the transversely oriented coils comprises: a magnetic channel 3D printed in the monolithic body such that the magnetic channel comprises at least one pair of opposing flux collectors having corresponding facets perpendicular to the second magnetic axis of the transversely oriented coil and at least one section therebetween serving 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 in the monolithic body to surround the at least one magnetic channel; and

[0125] The magnetic channel is bent within the monolithic body so that the at least one section thereof serving as the magnetic core extends along the printing direction, and the arrangement of the second conductive winding comprises a plurality of turns printed in the plane of the print layer to surround the at least one section serving as the magnetic core.

[0126] Embodiment 3. A magnetic field sensor according to embodiment 2, wherein the integral body has an elongated shape along the printing direction, wherein the pair of opposing flux collectors have a relatively short distance between them, and wherein the bending of the magnetic channel within the integral body facilitates the extended length of at least one section used as the magnetic core to accommodate a higher count of turns of the second conductive winding surrounding the extended length, thereby improving the sensitivity of the transversely oriented coil despite the short distance between the pair of flux collectors.

[0127] Embodiment 4. A magnetic field sensor according to any one of Embodiments 1 to 3, wherein the one or more longitudinal orientation coils include three longitudinal orientation coils having similar magnetic properties, the three longitudinal orientation coils being 3D printed so that they are co-aligned and their respective first magnetic axes are parallel to each other, thereby enabling the use of signals obtained from the three longitudinal orientation coils 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 approximate direction of the first magnetic axis; and

[0128] The one or more transverse orientation coils include two transverse orientation coils, which are 3D printed so that their corresponding two transverse orientation magnetic axes are not parallel to each other, and so that the two transverse orientation magnetic axes span 3D coordinates together with the longitudinal orientation magnetic axis of at least one of the one or more longitudinal orientation coils, thereby enabling the position and orientation of the sensor relative to one or more second magnetic field sources to be determined using signals obtained from the two transverse orientation coils and the at least one longitudinal orientation coil.

[0129] Embodiment 5. A magnetic field sensor according to embodiment 4, wherein the at least three longitudinally oriented coils are arranged in corresponding three angular sectors around the longitudinal axis of the integral body along the printing direction; and the at least two transversely oriented coils are arranged in corresponding two angular sectors around the longitudinal axis.

[0130] Embodiment 6. A magnetic field sensor according to Embodiment 5, wherein at least one of the following exists: (a) the three angular sectors and the two angular sectors are five co-aligned sectors arranged around the longitudinal axis of the integral body at the same level relative to the longitudinal axis (the same height relative to the longitudinal axis); and (b) the three angular sectors and the two angular sectors are respectively arranged at different levels (different heights) relative to the longitudinal axis of the integral body.

[0131] Embodiment 7. The magnetic field sensor of Embodiment 5 or 6, wherein the unitary body has a cylindrical shape with a characteristic width of about 2 millimeters about the longitudinal axis, thereby enabling the magnetic field sensor to be mounted within a catheter.

[0132] Embodiment 8. A magnetic field sensor according to embodiment 7, wherein the integral body has an annular shape having a hole passing therethrough along the longitudinal axis so as to facilitate passage of additional components of the catheter (e.g., electrical wires and / or fluid lines) through the hole of the sensor; and wherein a pair of opposing flux collectors of each of the transversely oriented coils includes a flux collector arranged at an outer facet of the annular shape and a flux collector located at a facet of the annular shape facing the hole.

[0133] Embodiment 9. The magnetic field sensor of any one of Embodiments 2 to 8, wherein the 3D printing provides a higher voxel resolution along the printing direction than the lateral voxel resolution within the printed layer; and

[0134] wherein the at least one segment serving as the magnetic core extends substantially parallel to the printing direction, and the turns of the second conductive winding surrounding the at least one segment are substantially perpendicular to the printing direction, thereby utilizing the higher voxel resolution along the printing direction to produce a high density of the turns of the second conductive winding and thereby improving the sensitivity of the transversely oriented coil.

[0135] Embodiment 10 The magnetic field sensor of any one of Embodiments 2 to 9, wherein the at least one magnetic channel is bent in a spiral or meander-like shape.

[0136] Embodiment 11 The magnetic field sensor of any one of Embodiments 2 to 9, wherein the at least one magnetic channel is bent in the shape of a coil wound around the second conductive winding.

[0137] Embodiment 12 The magnetic field sensor of any one of Embodiments 2 to 11, wherein the facets of the flux collector are wider than the at least one section serving as the magnetic core.

[0138] Embodiment 13. The magnetic field sensor of any one of Embodiments 2 to 11, wherein the magnetic channel is configured such that the transversely oriented coil has an open magnetic circuit configuration.

[0139] Embodiment 14. A magnetic field sensor according to any one of Embodiments 1 to 13, wherein at least one of the one or more longitudinally oriented coils comprises a magnetic channel 3D printed in the monolithic body, the magnetic channel having a pair of opposing flux collectors with corresponding facets perpendicular to the first magnetic axis and at least one magnetic core segment between the pair of opposing flux collectors; and wherein there is one or more of the following:

[0140] - the pair of flux collectors of the longitudinally oriented coil tapers towards the magnetic core section of the longitudinally oriented coil;

[0141] - the core segments of the longitudinally oriented coils are directed in the longitudinal direction in the form of rods;

[0142] - said magnetic path of said longitudinally oriented coil is bent in a coiled shape wound around said first conductive winding;

[0143] - the magnetic channel of the longitudinally oriented coil is bent within the monolithic body so that a greater length of the core segment is surrounded by the first winding of the longitudinally oriented coil,

[0144] thereby facilitating higher output voltage and improved sensitivity of the longitudinally oriented coil;

[0145] - the at least one longitudinally oriented coil is configured to have an open magnetic circuit configuration; and

[0146] - The pair of opposing flux collectors of the longitudinally oriented coil are arranged from opposite longitudinal sides of the unitary body of the sensor.

[0147] Embodiment 15. The magnetic field sensor of any one of embodiments 1 to 14, wherein the magnetic field sensor is formed by 3D printing at least three different 3D printable materials, wherein the at least three different 3D printable materials include:

[0148] - a magnetic material forming said magnetic channel;

[0149] - an electrically conductive material forming said electrically conductive winding; and

[0150] - a non-magnetic dielectric material forming the bulk of said monolithic body at areas excluding said magnetic material and said conductive material.

[0151] Embodiment 16. A magnetic field sensor according to embodiment 15, wherein the spaces between adjacent turns of the winding are occupied by a 3D printed non-conductive material, the 3D printed non-conductive material being one of a non-magnetic dielectric material and a 3D printed magnetic material; and wherein the conductive material of the winding is completely embedded within the monolithic body so as to be isolated from environmental conditions that may cause it to degrade.

[0152] Embodiment 17. The magnetic field sensor of Embodiment 15 or 16, wherein at least one of the following is present:

[0153] - the conductive material comprises silver;

[0154] - the conductive material comprises copper;

[0155] - the conductive material comprises palladium;

[0156] - the conductive material comprises a silver-palladium alloy;

[0157] - the magnetic material comprises a ceramic-ferrite material;

[0158] - the magnetic material comprises a metal material;

[0159] - The magnetic material has a relative magnetic permeability μ of about 100 or more r Soft magnetic materials and

[0160] - The non-magnetic dielectric material comprises a ceramic or glass-ceramic material.

[0161] Embodiment 18. A magnetic field sensor according to any one of Embodiments 1 to 17, wherein the electrical contact terminals of the electrical channel of the coil are arranged in a predetermined arrangement on the surface of the integral body, and wherein the magnetic field sensor also includes a signal connector, the signal connector including: a printed circuit board (PCB), the 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 integral body, and a signal cable, the signal cable having a signal line electrically coupled to the contact pad arrangement of the PCB; thereby facilitating electrical connection of the magnetic field sensor by coupling the PCB to the surface of the integral 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.

[0162] Embodiment 19. A method for manufacturing a magnetic field sensor, the method comprising 3D printing the magnetic field sensor by continuously printing layers along a printing direction to form an integral body of the sensor having one or more longitudinally oriented coils and one or more transversely oriented coils, wherein the one or more longitudinally oriented coils have corresponding first magnetic axes oriented substantially parallel to the printing direction, and the one or more transversely oriented coils have corresponding second magnetic axes oriented transversely to the printing direction.

[0163] Embodiment 20. The method of Embodiment 19, wherein 3D printing of each longitudinally oriented coil comprises 3D printing of a first conductive pathway, the 3D printing of the first conductive pathway forming an arrangement of first conductive windings having turns planarly printed in at least some of the printed layers; and

[0164] wherein the 3D printing of each transversely oriented coil comprises: 3D printing of a magnetic channel, the magnetic channel comprising at least one pair of opposing flux collectors, the at least one pair of opposing flux collectors having respective facets perpendicular to the second magnetic axis of the transversely oriented coil and at least one segment therebetween serving as a magnetic core of the transversely oriented coil; and 3D printing of a second conductive channel, the 3D printing of the second conductive channel forming an arrangement of a second conductive winding 3D printed in the monolithic body having turns around the at least one segment serving as the magnetic core;

[0165] Thus, the magnetic channel is printed with a curved path so that at least one section of the magnetic core serving as the transversely oriented coil extends substantially perpendicularly to the second magnetic axis along the printing direction; and the turns of the second conductive winding are planarly 3D printed within at least some of the printed layers to surround the magnetic core.

[0166] Embodiment 21. A method according to embodiment 20, wherein the pair of flux collectors are 3D printed across multiple printed layers so that they have corresponding flux collecting facets perpendicular to the second magnetic axis for efficiently collecting magnetic flux propagating from the direction of the second magnetic axis.

[0167] Embodiment 22. The method according to any one of embodiments 19 to 21, wherein the 3D printing comprises:

[0168] (a) providing a curable resin, the curable resin comprising:

[0169] - a magnetic material resin comprising magnetic material particles suspended in a curable polymer binder;

[0170] - a conductive material resin comprising conductive material particles suspended in a curable polymer binder;

[0171] - a non-magnetic dielectric material resin comprising non-magnetic dielectric material particles suspended in a curable polymer binder; and

[0172] (b) 3D printing the curable resin, comprising:

[0173] - 3D printing and curing the magnetic material resin in the area of ​​the magnetic channel;

[0174] - 3D printing and curing the conductive material resin at the regions of the first conductive pathway and the second conductive pathway; and

[0175] - 3D printing and curing the non-magnetic dielectric material at areas of the monolithic body not occupied by the magnetic channels and the conductive channels;

[0176] Thereby forming a 3D printed structure of the magnetic field sensor; and

[0177] (c) sintering the 3D printed structure of the magnetic field sensor at a temperature sufficient to burn or drive off polymer from the 3D printed structure of the magnetic field sensor, thereby achieving nearly 100% ceramic or metal density in the magnetic field sensor.

[0178] Embodiment 23. A method according to any one of Embodiments 20 to 22, wherein the monolithic body is printed along the printing direction to have an elongated shape, having a relatively short distance between the pair of opposing flux collectors, and wherein the bend of the magnetic channel within the monolithic body provides an extended length of at least one section serving as the magnetic core, thereby facilitating 3D printing of a higher count of turns of the second conductive winding around the extended length.

[0179] Embodiment 24. The method of any one of Embodiments 19 to 23, wherein the one or more longitudinally oriented coils include three longitudinally oriented coils having similar magnetic properties, the three longitudinally oriented coils being 3D printed such that they are co-aligned and their respective first magnetic axes are parallel to each other; and

[0180] The one or more transversely oriented coils include two transversely oriented coils, which are 3D printed so that their corresponding two transversely oriented magnetic axes are not parallel to each other, and so that the two transversely oriented magnetic axes span the 3D coordinates together with the longitudinally oriented magnetic axis of at least one of the one or more longitudinally oriented coils.

[0181] Embodiment 25. A method according to Embodiment 24, wherein the at least three longitudinally oriented coils are 3D printed in corresponding three angular sectors around a longitudinal axis of the integral body parallel to the printing direction; and the at least two transversely oriented coils are arranged in corresponding two angular sectors around the longitudinal axis.

[0182] Embodiment 26. A method according to Embodiment 25, wherein at least one of the following exists: (a) the three angular sectors and the two angular sectors are five co-aligned sectors 3D printed around the longitudinal axis of the monolithic body at the same level relative to the longitudinal axis (the same height relative to the longitudinal axis); and (b) the three angular sectors and the two angular sectors are 3D printed at different levels (different heights) relative to the longitudinal axis of the monolithic body, respectively.

[0183] Embodiment 27. A method according to Embodiment 26 or 25, wherein the monolithic body is 3D printed with a cylindrical shape around the longitudinal axis and has a characteristic width of about 2 mm to enable the magnetic field sensor to be mounted within a catheter.

[0184] Embodiment 28. A method according to embodiment 27, wherein the monolithic body is 3D printed with an annular shape and has a hole passing therethrough along the longitudinal axis to facilitate the passage of additional components of the catheter (e.g., wires and / or fluid lines) through the hole of the sensor; and wherein the pair of opposing flux collectors of each of the transversely oriented coils are 3D printed such that at least one flux collector is at an outer facet of the annular shape and at least one flux collector is at a facet of the annular shape facing the hole.

[0185] Embodiment 29. The method of any one of Embodiments 20 to 28, wherein the 3D printing provides a higher voxel resolution along the printing direction than the lateral voxel resolution within a printed layer; and

[0186] At least one section of the magnetic core serving as 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 utilizing the higher voxel resolution along the printing direction to produce a high density of the turns of the second conductive winding and improve the sensitivity of the transversely oriented coil.

[0187] Embodiment 30. The method of any one of Embodiments 19 to 29, wherein the at least one magnetic channel of the transversely oriented coil is bent in a spiral or meander-like shape.

[0188] Embodiment 31. The method of any one of Embodiments 20 to 29, wherein the at least one magnetic path of the transversely-oriented coil is bent in the shape of a coil wrapped around the second conductive winding.

[0189] Embodiment 32 The method of any one of Embodiments 20 to 31, wherein the facets of the flux collector are wider than the at least one section serving as the magnetic core.

[0190] Embodiment 33. A method according to any one of Embodiments 20 to 32, wherein the magnetic channel of the transversely oriented coil is configured so that the transversely oriented coil has an open magnetic circuit configuration.

[0191] Embodiment 34. The method of any one of Embodiments 19 to 33, wherein 3D printing of at least one of the one or more longitudinally oriented coils comprises 3D printing a magnetic channel within the monolithic body, the magnetic channel having a pair of opposing flux collectors with respective facets perpendicular to the first magnetic axis and at least one magnetic core segment between the pair of opposing flux collectors; and wherein one or more of the following are present:

[0192] - the pair of flux collectors of the longitudinally oriented coil are 3D printed such that they taper towards the magnetic core section of the longitudinally oriented coil;

[0193] - the core segments of the longitudinally oriented coils are 3D printed to extend along the longitudinal direction in the form of rods;

[0194] - the magnetic channel of the longitudinally oriented coil is 3D printed such that it is curved in a coiled shape wound around the first conductive winding;

[0195] - the magnetic channel of the longitudinally oriented coil is 3D printed such that it bends within the monolithic body to create a greater length of the core segment surrounded by the first winding of the longitudinally oriented coil;

[0196] - the at least one longitudinally oriented coil is 3D printed with an open magnetic circuit configuration; and

[0197] - The pair of opposing flux collectors of the longitudinally oriented coil are 3D printed from opposing longitudinal sides of the monolithic body of the sensor.

Claims

1. A magnetic field sensor, comprising: a monolithic body having a plurality of coils defined therein by 3D printing successive print layers along a print direction; The plurality of coils include: - one or more longitudinally oriented coils having respective first magnetic axes oriented substantially parallel to the printing direction; Each of the longitudinally oriented coils comprises a 3D printed first conductive pathway forming an arrangement of first conductive windings having turns in the plane of the printed layer; and - the plurality of coils further comprises one or more transversely oriented coils having respective second magnetic axes oriented transversely with respect to the printing direction.

2. The magnetic field sensor of claim 1 , wherein each of the transversely oriented coils comprises: a magnetic channel 3D printed in the monolithic body such that the magnetic channel includes at least one pair of opposing flux collectors having respective facets perpendicular to a second magnetic axis of the transversely oriented coil and at least one section therebetween 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 in the monolithic body to surround the at least one magnetic channel; and The magnetic channel forms a bend within the monolithic body so that the at least one section thereof serving as the magnetic core extends along the printing direction, and the arrangement of the second conductive winding comprises a plurality of turns printed in the plane of the print layer to surround the at least one section serving as the magnetic core.

3. A magnetic field sensor according to claim 2, wherein the integral body has an elongated shape along the printing direction, wherein the pair of opposing flux collectors have a relatively short distance between them, and wherein the bend of the magnetic channel within the integral body facilitates the use of an extended length of at least one section of the magnetic core to accommodate a higher count of 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 flux collectors.

4. The magnetic field sensor according to claim 1, wherein the one or more longitudinal orientation coils include three longitudinal orientation coils having similar magnetic properties, the three longitudinal orientation coils being 3D printed such that they are co-aligned and their respective first magnetic axes are parallel to each other, thereby enabling the determination of 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 approximate direction of the first magnetic axis using signals obtained from the three longitudinal orientation coils; and The one or more transverse orientation coils include two transverse orientation coils, which are 3D printed so that their corresponding two transverse orientation magnetic axes are not parallel to each other, and so that the two transverse orientation magnetic axes span 3D coordinates together with the longitudinal orientation magnetic axis of at least one of the one or more longitudinal orientation coils, thereby enabling the position and orientation of the sensor relative to one or more second magnetic field sources to be determined using signals obtained from the two transverse orientation coils and the at least one longitudinal orientation coil.

5. A magnetic field sensor according to claim 4, wherein the at least three longitudinally oriented coils are arranged in corresponding three angular sectors around the longitudinal axis of the integral body along the printing direction; and the at least two transversely oriented coils are arranged in corresponding two angular sectors around the longitudinal axis.

6. A magnetic field sensor according to claim 5, wherein at least one of the following exists: (a) the three angular sectors and the two angular sectors are five co-aligned sectors arranged around the longitudinal axis of the integral body in the same level; and (b) the three angular sectors and the two angular sectors are respectively arranged in different levels of the integral body.

7. The magnetic field sensor of claim 4, wherein the unitary body has a cylindrical shape about the longitudinal axis having a characteristic width of about 2 millimeters, thereby enabling the magnetic field sensor to be fitted within a catheter.

8. The magnetic field sensor of claim 7, wherein the unitary body has an annular shape having a hole 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 Wherein the pair of opposing flux collectors of each of the transversely oriented coils comprises a flux collector disposed at an outer facet of the annular shape and a flux collector located at a facet of the annular shape facing the aperture.

9. The magnetic field sensor of claim 2, wherein the 3D printing provides a higher voxel resolution along the printing direction than a lateral voxel resolution within a printed layer; and wherein the at least one segment serving as the magnetic core extends substantially parallel to the printing direction, and the turns of the second conductive winding surrounding the at least one segment are substantially perpendicular to the printing direction, thereby utilizing the higher voxel resolution along the printing direction to produce a high density of the turns of the second conductive winding and thereby improving the sensitivity of the transversely oriented coil. 10 . The magnetic field sensor of claim 2 , wherein the at least one magnetic channel is bent in a spiral-like shape or a meander-like shape. 11 . The magnetic field sensor of claim 2 , wherein the at least one magnetic channel is bent in a coil shape wound around the second conductive winding.

12. The magnetic field sensor of claim 2, wherein the facets of the flux collector are wider than the at least one section serving as the magnetic core.

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

14. The magnetic field sensor of any one of claims 1 to 13, wherein at least one of the one or more longitudinally oriented coils comprises a magnetic channel 3D printed in the monolithic body, the magnetic channel having a pair of opposing flux collectors with respective facets perpendicular to the first magnetic axis and at least one magnetic core segment between the pair of opposing flux collectors; and wherein there is one or more of the following: - the pair of flux collectors of the longitudinally oriented coil tapers towards the magnetic core section of the longitudinally oriented coil; - the core segments of the longitudinally oriented coils are directed in the longitudinal direction in the form of rods; - said magnetic path of said longitudinally oriented coil is bent in a coiled shape wound around said first conductive winding; - the magnetic path of the longitudinally oriented coil is bent within the monolithic body so that a greater length of the core segment is surrounded by the first winding of the longitudinally oriented coil, thereby facilitating a higher output voltage and improved sensitivity of the longitudinally oriented coil; - the at least one longitudinally oriented coil is configured to have an open magnetic circuit configuration; as well as - The pair of opposing flux collectors of the longitudinally oriented coil are arranged from opposite longitudinal sides of the unitary body of the sensor.

15. The magnetic field sensor according to claim 1, wherein the magnetic field sensor is formed by 3D printing at least three different 3D printable materials, wherein the at least three different 3D printable materials include: - a magnetic material forming the magnetic path of the coil; - an electrically conductive material forming an electrical path for the coil; as well as - a non-magnetic dielectric material forming the bulk of said monolithic body at areas excluding said magnetic material and said conductive material.

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

17. The method of claim 15, wherein at least one of the following is present: - 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 metal material; - The magnetic material has a relative magnetic permeability μ of about 100 or more r Soft magnetic materials; and - The non-magnetic dielectric material comprises a ceramic or glass-ceramic material.

18. The magnetic field sensor of claim 1 , wherein electrical contact terminals of the electrical channels of the coil are arranged on a surface of the monolithic body in a predetermined arrangement, and wherein the magnetic field sensor further comprises a signal connector, the signal connector comprising: a printed circuit board (PCB) having a complementary arrangement of contact pads that matches the arrangement of the electrical contact terminals of the coil at the surface of the integral 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 integral body so 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 of manufacturing a magnetic field sensor, The method includes 3D printing the magnetic field sensor by successively printing layers along a printing direction to form a monolithic body of the sensor having one or more longitudinally oriented coils and one or more transversely oriented coils, wherein the one or more longitudinally oriented coils have corresponding first magnetic axes oriented substantially parallel to the printing direction, and the one or more transversely oriented coils have corresponding second magnetic axes oriented transverse to the printing direction.

20. The method of claim 19, wherein 3D printing of each longitudinally oriented coil comprises 3D printing of a first conductive pathway, the 3D printing of the first conductive pathway forming an arrangement of first conductive windings having turns printed planarly in at least some of the printed layers; and The 3D printing of each transversely oriented coil includes: 3D printing of a magnetic channel, the magnetic channel comprising at least one pair of opposing flux collectors having respective facets perpendicular to the second magnetic axis of the transversely oriented coil and at least one segment therebetween serving as a magnetic core for the transversely oriented coil; and 3D printing of a second conductive channel, the 3D printing of the second conductive channel forming an arrangement of a second conductive winding 3D printed in the monolithic body having turns around the at least one segment serving as the magnetic core; Thus, the magnetic channel is printed with a curved path so that at least one section of the magnetic core serving as the transversely oriented coil extends substantially perpendicularly to the second magnetic axis along the printing direction; and the turns of the second conductive winding are planarly 3D printed within at least some of the printed layers to surround the magnetic core.

21. The method of claim 20, wherein the pair of flux collectors are 3D printed across a plurality of the printed layers such that they have corresponding flux collecting facets perpendicular to the second magnetic axis for efficiently collecting magnetic flux propagating from the direction of the second magnetic axis.

22. The method of claim 19, wherein the 3D printing comprises: (a) providing a curable resin, the curable resin comprising: - a magnetic material resin comprising magnetic material particles suspended in a curable polymer binder; - a conductive material resin comprising conductive material particles suspended in a curable polymer binder; - a non-magnetic dielectric material resin comprising non-magnetic dielectric material particles suspended in a curable polymer binder; and (b) 3D printing the curable resin, comprising: - 3D printing and curing the magnetic material resin in the area of ​​the magnetic channel of the coil; - 3D printing and curing the conductive material resin in the area of ​​the conductive path of the coil; and - 3D printing and curing the non-magnetic dielectric material at areas of the monolithic body not occupied by the magnetic channels and the conductive channels; Thereby forming a 3D printed structure of the magnetic field sensor; and (c) sintering the 3D printed structure of the magnetic field sensor at a temperature sufficient to burn or drive off polymer from the 3D printed structure of the magnetic field sensor, thereby achieving nearly 100% ceramic or metal density in the magnetic field sensor.

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