catheter contact force sensor

Abstract

A spring assembly usable with an intravascular catheter may include a tubular body, two mounting surfaces, and a compressible frame. The tubular body extends along a longitudinal axis and is sized to traverse the vascular system. Each mounting surface may be configured to engage substantially planar circuitry and is respectively positioned within the tubular body in a corresponding plane perpendicular to the longitudinal axis. The mounting surfaces face each other in opposing directions. The compressible frame extends between the first and second mounting surfaces. The spring assembly may also include a pair of circuitry mounted to the paired mounting surfaces. Each circuit may include an induction coil, such that the pair of circuitry is a distance transducer. Changes in distance between the pair of circuitry can be detected when the compressible frame is compressed and / or bent.

Description

Technical Field

[0001] This disclosure relates to instruments for measuring force, pressure, mechanical tension and / or mechanical compression for diagnostic and surgical procedures, and more specifically to catheter-based probes for diagnostic and / or surgical procedures in the heart. Background Technology

[0002] When a region of the heart tissue abnormally transmits electrical signals to adjacent tissues, arrhythmias (such as atrial fibrillation) occur, disrupting the normal cardiac cycle and leading to irregular heartbeats.

[0003] Procedures for treating cardiac arrhythmias involve surgically disrupting the signal sources causing the arrhythmia, as well as disrupting the conduction pathways used to transmit such signals. By selectively ablating cardiac tissue through the application of energy via a catheter, it can sometimes be possible to block or alter the propagation of unwanted electrical signals from one part of the heart to another. Ablation methods destroy unwanted electrical pathways by creating non-conductive ablation foci.

[0004] Various attempts have been made or suggested in the art for verifying electrodes that make contact with tissue, including using a multi-pressure transducer (patents 6,695,808 and 6,241,724), using electrodes to measure electrical activity in the heart (US Patent 6,915,149), using an electromechanical motion sensor (US Patent Application Publication 2007 / 0100332), measuring the impedance between a tip electrode and a return electrode (US Patents 5,935,079, 5,836,990 and 5,447,529), and using fluorescence fluoroscopic imaging (US Patent Publication 2005 / 0203597).

[0005] U.S. Patent Application Publication 2009 / 0093806, granted to Govari et al., describes another application of contact pressure measurement in which a sensor is used to measure deformation in response to pressure on an elastic member located at the distal end of a conduit. The entire contents of that patent application publication are incorporated herein by reference, as fully set forth in the appendix to priority application US62 / 943,572.

[0006] U.S. Patent 9,168,004, granted to Gliner et al., describes the use of machine learning to determine catheter electrode contact based on the impedance between two electrodes. The entire contents of that patent application are incorporated herein by reference, as fully set forth in the appendix to priority application US62 / 943,572.

[0007] U.S. Patent Publication 2018 / 0256110 to Govari et al. describes a flexible probe having a pair of spring coils and a transducer having transmitter and receiver circuitry located on either side of the spring coils, the entire contents of which are incorporated herein by reference, as fully set forth in the appendix to priority application US62 / 943,572. The spring coils deform in response to pressure applied to the distal tip of the probe, causing the transmitter and receiver circuitry to move relative to each other. Summary of the Invention

[0008] According to some embodiments of this disclosure, a spring assembly capable of being used with an intravascular catheter is provided. The spring assembly may include a tubular body, a first mounting surface configured to engage a substantially planar circuit, a second mounting surface configured to engage a substantially planar circuit, and a compressible frame extending between the first and second mounting surfaces. The tubular body extends along a longitudinal axis. The tubular body is sized to traverse a vascular system. The first mounting surface is positioned within the tubular body, perpendicular to the longitudinal axis, and facing a first direction parallel to the longitudinal axis. The second mounting surface is positioned within the tubular body, perpendicular to the longitudinal axis, and facing the first mounting surface in a second direction opposite to the first direction.

[0009] In some embodiments, the spring assembly further includes a first opening in the tubular body and a second opening in the tubular body. The first opening is defined by a first mounting surface and a compressible frame. The second opening is defined by a second mounting surface and a compressible frame. The first and second openings are at least partially collapsible in response to compression of the compressible frame.

[0010] In some embodiments, the spring assembly also includes one or more openings defined by a compressible frame. The one or more openings defined by the compressible frame are at least partially collapsible in response to compression of the compressible frame.

[0011] In some embodiments, the spring assembly further includes a third, fourth, fifth, and sixth mounting surface, each configured to engage a substantially planar circuit and positioned within a tubular body. The first, third, and fifth mounting surfaces are coplanar in a first plane perpendicular to the longitudinal axis. The second, fourth, and sixth mounting surfaces are coplanar in a second plane perpendicular to the longitudinal axis. The third and fourth mounting surfaces face each other. The fifth and sixth mounting surfaces face each other.

[0012] In some embodiments, the spring assembly includes a first opening, a second opening, a third opening, a fourth opening, and a fifth opening. The first opening in the tubular body is defined by a first mounting surface and a compressible frame. The second opening in the tubular body is defined by a second mounting surface and a compressible frame. The third opening in the tubular body is defined by a third mounting surface and a compressible frame. The fourth opening in the tubular body is defined by a fourth mounting surface and a compressible frame. The fifth opening in the tubular body is defined by a fifth mounting surface and a compressible frame. The sixth opening in the tubular body is defined by a sixth mounting surface and a compressible frame. The spring assembly may also include three additional openings, each defined by a compressible frame.

[0013] In some embodiments that include a first mounting surface, a second mounting surface, a third mounting surface, a fourth mounting surface, a fifth mounting surface, and a sixth mounting surface, each mounting surface has dimensions substantially similar to each of the remaining mounting surfaces.

[0014] In some embodiments that include a first mounting surface, a third mounting surface, and a fifth mounting surface, the first mounting surface, the third mounting surface, and the fifth mounting surface are spaced 120° apart from each other, as measured by rotation about a longitudinal axis.

[0015] In some embodiments that include a second mounting surface, a fourth mounting surface, and a sixth mounting surface, the second mounting surface, the fourth mounting surface, and the sixth mounting surface are spaced 120° apart from each other, as measured by rotation about a longitudinal axis.

[0016] In some embodiments, the first mounting surface includes a plurality of T-shaped notches thereon, and / or the second mounting surface includes a plurality of T-shaped notches thereon. Some or all of the mounting surfaces include a plurality of T-shaped notches thereon.

[0017] In some embodiments, the spring assembly further includes a plurality of engaging extensions extending from a first end of the tubular body in a first direction and a plurality of engaging extensions extending from a second end of the tubular body in a second direction. Each engaging extension on either side of the tubular body includes a protrusion extending from the engaging extension in a circumferential direction about a longitudinal axis.

[0018] In some embodiments that include multiple engagement extensions, the spring assembly includes exactly three engagement extensions extending from a first end of the tubular body in a first direction and exactly three engagement extensions extending from a second end of the tubular body in a second direction.

[0019] In some embodiments, the spring assembly further includes a first circuit and a second circuit. The first circuit is attached to a first mounting surface. The first circuit includes a first induction coil. The second circuit is attached to a second mounting surface. The second circuit includes a second induction coil.

[0020] In some embodiments, including a first mounting surface, a second mounting surface, a third mounting surface, a fourth mounting surface, a fifth mounting surface, and a sixth mounting surface, and a first circuit and a second circuit, the spring assembly further includes a third circuit, a fourth circuit, a fifth circuit, and a sixth circuit. The first circuit is attached to the first mounting surface. The first circuit includes a first induction coil. The second circuit is attached to the second mounting surface. The second circuit includes a second induction coil. The third circuit is attached to the third mounting surface. The third circuit includes a third induction coil. The fourth circuit is attached to the fourth mounting surface. The fourth circuit includes a fourth induction coil. The fifth circuit is attached to the fifth mounting surface. The fifth circuit includes a fifth induction coil. The sixth circuit is attached to the sixth mounting surface. The sixth circuit includes a sixth induction coil.

[0021] In some embodiments that include a first circuit, a second circuit, a third circuit, a fourth circuit, a fifth circuit, and a sixth circuit, the spring assembly may further include a first circuit segment, a second circuit segment, a third circuit segment, and a fourth circuit segment, each extending on the outer surface of the tubular body. The first circuit segment connects the first circuit to the third circuit. The second circuit segment connects the third circuit to the fifth circuit. The third circuit segment connects the second circuit to the fourth circuit. The fourth circuit segment connects the fourth circuit to the sixth circuit.

[0022] According to some embodiments of this disclosure, a force probe is also provided, comprising a tubular segment, a first mounting surface in the tubular segment, a second mounting surface in the tubular segment, a compressible frame extending between the first and second mounting surfaces, a catheter, and an atraumatic probe tip. The tubular segment extends along a longitudinal axis. The tubular segment is sized to traverse a vascular system. The first mounting surface is configured to engage substantially planar circuitry. The first mounting surface is located in a sidewall of the tubular segment, perpendicular to the longitudinal axis, and facing a first direction parallel to the longitudinal axis. The second mounting surface is configured to engage substantially planar circuitry. The second mounting surface is located in a sidewall of the tubular segment, perpendicular to the longitudinal axis, and facing the first mounting surface in a second direction opposite to the first direction. A catheter is attached to a first end of the tubular segment. An atraumatic probe tip is attached to a second end of the tubular segment.

[0023] According to some embodiments of this disclosure, an intravascular force probe is also provided, comprising a proximal tube, a non-invasive distal end, a first induction coil, a second induction coil, and a compressible frame. The proximal portion includes an elongated body sized to traverse the vascular system. The proximal tube and the non-invasive distal end define a longitudinal axis along which the force probe extends. The first and second induction coils are each attached between the proximal tube and the non-invasive distal end. The first induction coil is confined in a first plane perpendicular to the longitudinal axis. The second induction coil is confined in a second plane perpendicular to the longitudinal axis. The compressible frame is compressible parallel to the longitudinal axis to move the first and second induction coils toward each other.

[0024] In some embodiments, the endovascular force probe further includes a catheter coupler attached to the proximal tube and the non-invasive distal end. The catheter coupler includes a compressible frame. The catheter coupler structurally supports a first induction coil and a second induction coil.

[0025] In some embodiments, the endovascular force probe further includes a first connecting conductor electrically connected to the first induction coil. The first connecting conductor extends circumferentially about a longitudinal axis in a first plane and is positioned outside the outer surface of the catheter coupler.

[0026] In some embodiments, the endovascular force probe further includes a third, fourth, fifth, and sixth induction coil. The third and fifth induction coils are confined in a first plane. The fourth and sixth induction coils are confined in a second plane.

[0027] In some implementations, the compressible frame is capable of bending to define a bend in the longitudinal axis, resulting in the first plane and the second plane being non-parallel.

[0028] In some implementations, the vascular force probe further includes a generator and an electrical measuring tool. The generator is electrically connected to a first induction coil. The electrical measuring tool is electrically connected to a second induction coil.

[0029] In some embodiments, the endovascular force probe further includes an electrodiagnostic system configured to receive a first electrical signal corresponding to a first distance between a first induction coil and a second induction coil, a second electrical signal corresponding to a second distance between a third induction coil and a fourth induction coil, a third electrical signal corresponding to a third distance between a fifth induction coil and a sixth induction coil, and to determine a three-dimensional force vector representing a force applied to the non-invasive distal end, the force vector being determined at least in part based on the first, second, and third electrical signals.

[0030] According to some embodiments of this disclosure, a catheter is also provided, which includes a proximal tube, an atraumatic distal end, a first induction coil, a second induction coil, a compressible frame, a catheter coupler, and an elongated catheter fitting.

[0031] The proximal tube and the non-invasive distal end define the longitudinal axis.

[0032] The first induction coil is attached between the proximal tube and the non-invasive distal end. The first induction coil is confined in a first plane perpendicular to the longitudinal axis.

[0033] The second induction coil is attached between the proximal tube and the non-invasive distal end and is confined in a second plane perpendicular to the longitudinal axis.

[0034] The compressible frame can be compressed parallel to the longitudinal axis to move the first induction coil and the second induction coil toward each other.

[0035] The catheter coupler is attached to the proximal tube and the non-invasive distal end. The catheter coupler includes a compressible frame and structurally supports a first induction coil and a second induction coil.

[0036] The slender catheter fitting is attached to the proximal tube, surrounds the first induction coil, surrounds the second induction coil, surrounds the compressible frame, surrounds the catheter coupler, and extends to the proximal end of the catheter.

[0037] The invention will be more fully understood from the following detailed description of embodiments of the present disclosure taken in conjunction with the accompanying drawings. Attached Figure Description

[0038] Figure 1 Illustrations of spring assemblies according to some embodiments of the present invention;

[0039] Figure 2 A top outline view of a conduit coupler for a spring assembly according to some embodiments of the present disclosure;

[0040] Figure 3 This is an illustration of a cross-sectional view of a catheter coupler according to some embodiments of this disclosure;

[0041] Figure 4 A top profile view of a spring assembly according to some embodiments of the present disclosure;

[0042] Figure 5 A circuit diagram of a spring assembly according to some embodiments of this disclosure;

[0043] Figure 6A and Figure 6B This is a diagram illustrating the sequence for opening the circuit to insert the spring assembly according to some embodiments of this disclosure;

[0044] Figure 7 A diagram illustrating a circuit having a shaped connection segment for strain relief according to some embodiments of this disclosure;

[0045] Figure 8 A diagram illustrating another circuit of a spring assembly according to some embodiments of this disclosure;

[0046] Figure 9 A diagram illustrating a component of a force probe for a partially assembled conduit, including a spring assembly, according to some embodiments of this disclosure;

[0047] Figure 10 This is another illustration of a force probe component of a conduit partially assembled with a spring assembly, according to some embodiments of this disclosure; and

[0048] Figure 11 Illustrations of medical treatment using catheters and force probes according to some embodiments of this disclosure. Detailed Implementation

[0049] As used herein, the term “about” or “approximately” for any numerical value or range indicates a suitable dimensional tolerance that allows a collection of parts or elements to achieve the intended purpose as described herein. More specifically, “about” or “approximately” may refer to a range of values ​​±10% of the enumerated values; for example, “about 90%” may refer to a range of values ​​from 81% to 99%. Additionally, as used herein, the terms “patient,” “host,” “user,” and “subject” refer to any human or animal subject and are not intended to limit the system or method to human use, but the use of the subject matter invention in human patients represents a preferred embodiment.

[0050] As used herein, the term "computing system" is intended to include a standalone machine or device and / or a combination of machines, components, modules, systems, servers, processors, memory, detectors, user interfaces, computing device interfaces, network interfaces, hardware elements, software elements, firmware elements, and other computer-related units. By way of example, and not limitation, a computing system may include one or more of a general-purpose computer, a special-purpose computer, a processor, a portable electronic device, a portable electronic medical device, a fixed or semi-fixed electronic medical device, or other electronic data processing equipment.

[0051] As used herein, the terms “component,” “module,” “system,” “server,” “processor,” “memory,” etc., are intended to include one or more computer-related units, such as, but not limited to, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a processor, an object, an executable file, an execution thread, a program, and / or a process running on a computer. By way of example, both an application running on a computing device and the computing device itself can be components. One or more components may reside within a process and / or an execution thread, and components may be located on a single computer and / or distributed across two or more computers. Furthermore, these components may be executed by various computer-readable media on which various data structures are stored. Components may communicate via local and / or remote processes, such as data from a component interacting with a local system, another component in a distributed system, and / or other systems via a network such as the Internet, according to signals having one or more data packets. The computer-readable medium may be non-transitory. Non-transitory computer-readable media include, but are not limited to, random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory or other memory technologies, optical disc ROM (CD-ROM), digital versatile optical disc (DVD) or other optical storage devices, magnetic tape cassettes, magnetic tapes, disk storage devices or other magnetic storage devices, or any other tangible physical medium that can be used to store computer-readable instructions and / or data.

[0052] As used herein, the term "trace" includes conductive paths in a circuit, such as paths integral with a printed circuit, individual wires, conductors within a cable, or other such structures known and understood by one of ordinary skill in the art based on the teachings of this disclosure.

[0053] As used herein, the terms "tubular" and "tube" are not limited to structures that are perfectly cylindrical or have a perfectly circular cross-section or a uniform cross-section over their entire length. For example, tubular structures or systems are generally shown as structures that are substantially cylindrical. However, without departing from the scope of this disclosure, tubular systems may have tapered outer surfaces, curved outer surfaces, and / or partially flat outer surfaces.

[0054] Figure 1A spring assembly 100 is shown, comprising a catheter coupler 190, a distal circuit 180, and a proximal circuit 110. The spring assembly 100 is sized to traverse the vascular system; therefore, all components and their sub-components are sized to traverse the vascular system. The catheter coupler 190 is compressible, causing opposing portions 114 of the distal circuit 180 and the proximal circuit 110 to move relative to each other. The distal circuit 180 and the proximal circuit 110 are configured to provide electrical signals indicating one or more distances (or changes in distance) at one or more locations between the opposing portions 114 of the distal circuit 180 and the proximal circuit 110.

[0055] The catheter coupler 190 has a tubular body defining a longitudinal axis LL extending therethrough. The catheter coupler 190 is sized to traverse the vascular system. The catheter coupler 190 includes a compressible frame 196 that can be compressed when a force is applied along the longitudinal axis LL to the spring assembly 100. The compressible frame 196 can also be deflected by a force not parallel to the longitudinal axis, thereby causing the coupler 190 to bend. Because the longitudinal axis LL is defined by the tubular body of the coupler 190, bending in the coupler 190 thus produces bending along the longitudinal axis LL.

[0056] Coupler 190 includes a distal mounting surface 206, 210, 224 to which distal circuitry 180 is attached, and a proximal mounting surface 204, 208, 222 to which a portion 114 of proximal circuitry 110 is attached. Mounting surfaces 204, 206, 208, 210, 222, 224 are each configured to engage substantially planar circuitry, such as the opposing portions 114 of distal circuitry 180 and proximal circuitry 110. Each mounting surface 204, 206, 208, 210, 222, 224 is substantially perpendicular to the longitudinal axis LL. Each of the proximal mounting surfaces 204, 208, and 222 faces the corresponding mounting surface of the distal mounting surfaces 206, 210, and 224, such that each of the proximal mounting surfaces 204, 208, and 222 faces a first direction parallel to the longitudinal axis, and each of the distal mounting surfaces faces the corresponding proximal mounting surface 204, 208, and 222 in a second direction opposite to the first direction and parallel to the longitudinal axis. The size and shape of each of the proximal mounting surfaces 204, 208, and 222 can be set as a mirror image facing the distal mounting surfaces 206, 210, and 224.

[0057] Coupler 190 may include three distal mounting surfaces 206, 210, 224 coplanar in a first plane P1 and three proximal mounting surfaces 204, 208, 222 coplanar in a second plane P2. The first plane P1 and the second plane P2 are each perpendicular to the longitudinal axis LL. The first distal surface 206 is positioned opposite the second proximal surface 204; the third distal surface 210 is positioned opposite the fourth proximal surface 208; and the fifth distal surface 224 is positioned opposite the sixth proximal surface 222. The first surface 206, the third surface 210, and the fifth surface 224 are coplanar in the first plane P1. The second surface 204, the fourth surface 208, and the sixth surface 222 are coplanar in the second plane P2. The first mounting surface 204, the second mounting surface 206, the third mounting surface 208, the fourth mounting surface 210, the fifth mounting surface 222, and the sixth mounting surface 224 have substantially similar dimensions to each other. The first mounting surface 206, the third mounting surface 210, and the fifth mounting surface 224 are spaced 120° apart, as measured by rotation about the longitudinal axis. The second mounting surface 204, the fourth mounting surface 208, and the sixth mounting surface 222 are also spaced 120° apart, as measured by rotation about the longitudinal axis.

[0058] Each mounting surface 204, 206, 208, 210, 222, 224 is positioned in the sidewall of the tubular body of the coupler 190.

[0059] The compressible frame 196 extends from the proximal mounting surfaces 204, 208, 222 to the distal mounting surfaces 206, 210, 224.

[0060] The catheter coupler 190 is further configured to engage the two portions of the catheter 14 (see Figure 11 The catheter coupler 190 has a distal engagement extension 194 extending to the distal end of the tubular body and a proximal engagement extension 192 extending to the proximal end of the tubular body.

[0061] The opposing portions 114 of the distal circuit 180 and the proximal circuit 110 may include induction coils positioned opposite each other. Each induction coil may be positioned opposite another induction coil, with a compressible frame 196 between them. The opposing coils may be configured to act as sensing distance sensors, wherein one or more coils (preferably on portion 114 of the proximal circuit 110) act as transmitters and one or more opposing coils (preferably on the distal circuit 180) act as receivers. The force probe, including the spring assembly 100, may include a generator electrically connected to the coil acting as the transmitter and an electrical measuring tool electrically connected to the coil acting as the receiver.

[0062] The remote circuit 180 may include three induction coils 184 (see Figure 8The adjacent portion 114 of the proximal circuit 110 may include three induction coils 116, 118, and 120 (see [link to relevant documentation]). Figure 5 Each of the induction coils 184 on the distal circuit 180 can be positioned opposite a corresponding induction coil 116, 118, 120 on the proximal circuit 110. The induction coils 184 on the distal circuit 180 can be constrained to a plane perpendicular to the longitudinal axis LL by means of distal mounting surfaces 206, 210, 224 attached to the coupler 190 (the distal mounting surfaces are coplanar in the first plane P1) and also by means of, for example, planar coils. The induction coils 116, 118, 120 on the opposite portions 114 of the proximal circuit 110 can be constrained to a plane perpendicular to the longitudinal axis LL by means of proximal mounting surfaces 204, 208, 222 attached to the coupler 190 (the proximal mounting surfaces are coplanar in the second plane) and also by means of, for example, planar coils.

[0063] The intravascular force probe may include six induction coils 184, 116, 118, and 120 arranged in pairs to form three sensing distance sensors. The force probe may also include an electrodiagnostic system configured to receive first, second, and third electrical signals corresponding to first, second, and third distances between the first, second, and third coil pairs, respectively. The electrodiagnostic system may also be configured to determine a three-dimensional force vector representing the force applied to the tip of the force probe, based at least in part on the first, second, and third electrical signals.

[0064] Coupler 190 can structurally support induction coils 184, 116, 118, and 120.

[0065] The proximal circuit 110 may also include additional circuit segments 124, 134, 142 for connections to additional sensors and / or power sources. (See also...) Figure 5 。 )

[0066] Figure 2 This is a top-view outline diagram of the conduit coupler 190. Figure 3 yes Figure 2 A diagram of the cross-section of the conduit coupler 190. See also: Figure 2 and Figure 3The tubular body of the coupler 190 includes openings 232, 234, and 236 in a region of the compressible frame 196. As shown, the tubular body includes three proximal openings 232, each defined by one of proximal mounting surfaces 204, 208, and 222 and a strut 226 of the compressible frame 196. As shown, the tubular body includes three distal openings 234, each defined by one of distal mounting surfaces 206, 210, and 224 and a strut 226 of the compressible frame. As shown, the tubular body includes three central openings 236, each defined by a strut 226 of the compressible frame 196.

[0067] The struts 226 and openings 232, 234, 236 in the compressible frame may alternatively be configured to allow compression and / or bending of the compressible frame 196 when the spring assembly 100 is manipulated as part of the catheter force probe. The size, shape, and positioning of the struts 236 may be set and may otherwise be configured to provide a predetermined travel length (in the longitudinal axis LL and / or off-axis directions) and / or a predetermined spring constant. The spring constant and / or travel length may be determined based on the clinical working range required for a particular application or application range. The struts 236 may be designed to produce a specific travel length and spring constant based on the clinical working range of contact forces required in a particular application (e.g., 500g or less).

[0068] When the compressible frame 196 is compressed, some or all of the openings 232, 234, 236 in the tubular body may collapse. When the compressible frame 196 is compressed, the openings 232, 234, partially defined by one of the mounting surfaces 204, 206, 208, 210, 222, 224, may collapse. Additionally or alternatively, when the compressible frame 196 is compressed, the opening 236 defined by the struts 226 of the compressible frame 196 may collapse.

[0069] Each mounting surface 204, 206, 208, 210, 222, 224 may be configured to receive a liquid adhesive suitable for adhering to the distal circuit 180 and the proximal circuit 110. Each mounting surface 204, 206, 208, 210, 222, 224 may include a T-shaped notch 228 in which the adhesive can flow. Compared to a smooth planar mounting surface, the T-shaped notch 228 provides improved fixation for adhesion of the mounting surfaces 204, 206, 208, 210, 222, 224. As will be understood and appreciated by those skilled in the art based on the teachings of this disclosure, each mounting surface 204, 206, 208, 210, 222, 224 may be treated in other ways to improve adhesion.

[0070] The coupler 190 may further include a plurality of engagement extensions 194 extending from a first end of the tubular body and parallel to the longitudinal axis LL, and a plurality of engagement extensions 192 extending from a second end of the tubular body and parallel to the longitudinal axis LL. Each engagement extension 192, 194 on either side of the tubular body may include a protrusion 192, 195 extending from the engagement extension in a circumferential direction about the longitudinal axis. The spring assembly may include exactly three engagement extensions 192 extending from the first end of the tubular body and exactly three engagement extensions 194 extending from the second end of the tubular body.

[0071] Figure 4 This is a top profile view of the distal portion of the spring assembly 100, providing a view of the relative positions 114 of the distal circuit 180 and the proximal circuit 110 within the spring assembly 100. In this view, four circuit segments 132, 136, and 186 can be observed extending beyond the outer surface of the tubular body of the coupler 190.

[0072] The distal circuit 180 is in Figure 8 More details are shown below. See also: Figure 4 and Figure 8 The distal circuit 180 includes two segments 186, each extending on the outer surface of the tubular body of the coupler 190. Each segment 186 connects to one of the two larger portions 178 of the distal circuit 180, such that the three larger portions 178 of the distal circuit 180 are connected via the two segments 186. An induction coil 184 of the distal circuit 180 is located within the larger portions 178 of the distal circuit 180.

[0073] Proximal circuit 110 in Figure 5 More details are shown below. See also: Figure 4 and Figure 5 A portion 114 of the proximal circuit 110, positioned relative to the distal circuit 180, includes two connecting segments 132 and 136. The first connecting segment 132 of the proximal circuit 110 connects a first larger portion 164 to a second larger portion 162. The second segment 136 of the proximal circuit 110 connects the second larger portion 162 to a third larger portion 160.

[0074] When the corresponding circuits 180, 114 are mounted to the coupler 190, the larger portions 160, 162, 164, 178 can each be shaped to extend across each corresponding mounting surface 204, 206, 208, 210, 222, 224 into a cavity 212 defined by the inner surface of the coupler 190. Connecting segments 132, 136, 186 are positioned to extend on the outer surface of the coupler 190. Each segment 132, 136, 186 and its paired adjacent larger portions 160, 162, 164, 178 form a notch, into which a portion of the strut frame 196 between the mounting surfaces 204, 206, 208, 210, 222, 224 can be positioned. With this configuration, circuits 180, 114 can be positioned in planes P1, P2 (perpendicular to the longitudinal axis LL). Figure 1 They are aligned parallel to each other. Compared to some other known force sensor designs, circuits 114 and 180 can be positioned closer to each other.

[0075] Figure 5 This illustration shows a flexible circuit 110 that can be used as a proximal circuit 110 in a spring assembly 100. The flexible circuit 110 can be used within a catheter to provide a signal about force to a processor at a physician control console. The flexible circuit 110 may also include circuitry for providing a signal about position. The flexible circuit 110 includes a generally planar substrate 112 that includes a generally circular portion 114. The circular portion 114 is shaped to fit within a catheter coupler 190 opposite to the distal circuit 180, as... Figure 1 and Figure 4 As shown. The substrate 112 includes additional portions 124, 134, 142 shaped to enclose the longitudinal axis LL. The additional portions 124, 134, 142 may have a generally rectangular shape or other shapes as shown. The portions 114, 124, 134, 142 can be joined by connector segments 144, 146, 148. The widths of the rectangular portions 124, 134, 142 and the associated connector segments 146, 148 can be dimensional such that when enclosed within or around a conduit, sleeve, sheath, or other such tubular structure, the additional portions 124, 134, 142 almost completely define the longitudinal axis LL. The substrate 112 may be formed of a suitable non-conductive material and resistant to high temperatures, such as polyimide, polyamide, or liquid crystal polymer (LCP). Alternatively, some or all of segments 114, 124, 134, 142 and segments 144, 146, 148 may be constructed on a substrate separate from substrate 112 and joined by methods known to those skilled in the art to form circuit 110.

[0076] The circular portion 114 of circuit 110 includes three larger parts 160, 162, and 164, and two connecting segments 132 and 136, as per [reference to...]. Figure 4As shown and described. Each of the three larger portions 160, 162, and 164 is an annular sector of the circular portion 114. The annular sectors 160, 162, and 164 may have substantially the same shape as each other. The first annular sector 164 is separated from the third annular sector 160 by an opening 122 in the circular portion 114. Segments 132 and 136 may be flexible, such that the circular portion 114 can be opened to be inserted into the coupler 190 and positioned as shown. Figure 4 The final position shown.

[0077] Figure 6A Is it like this? Figure 5 The illustration shows the circular portion 114 in a top view with a relaxed shape. Figure 6B This is a top view illustration of the circular portion 114 opened to be inserted into the coupler 190.

[0078] The entire circular portion 114 can be flexible. Alternatively, the annular sectors 160, 162, and 164 can be rigid, rather than substantially elastically deformable. Regardless of whether the annular sectors 160, 162, and 164 are rigid or flexible during manufacture, when attached to the coupler 190, the annular sectors 160, 162, and 164 can be sufficiently rigid to hold the induction coil in the second plane P2 (see [link to coupler]) during transport, pre-operation processing, and handling. Figure 1 The positions of segments 132 and 136 are such that the circular portion 114 can be mounted into the coupler 190.

[0079] Segments 132 and 136 may be rigidly attached to coupler 190. Alternatively, when annular sector 178 is attached to the coupler, segments 132 and 136 may be flexible to provide strain relief between annular sectors 178. For example, segments 132 and 136 may include an S-shaped configuration that can be positioned flat against the outer diameter of coupler 190.

[0080] Figure 7 A top view illustration shows a circular circuit 114a with radially outwardly extending segments 132a, 136a. Segments 132a, 136a are shaped to provide strain relief. When the circular circuit 114a is attached to the coupler 190, segments 132a, 136a are separated from the outer surface of the coupler 190 for at least a portion of the length of each respective segment 132a, 136a. Segments 132, 136 may alternatively be shaped such that the segment can lengthen as the coupler 190 bends.

[0081] Each annular sector 160, 162, 164 includes induction coils 116, 118, 120. Coils 116, 118, 120 may be separate from each other, as shown, or they may each be connected to one or both of the other coils. As shown, each coil 116, 118, 120 on the circular portion 114 includes approximately five turns. However, because signal strength is a function of the number of turns, the number of turns can be maximized based on the size of each segment and the pitch achievable by the photolithography process.

[0082] Each segment 132, 136 may include connecting traces 166, 176 electrically connected to one or more of the induction coils 116, 120. The traces 166, 176 in the connecting segments 132, 136 may extend circumferentially around a longitudinal axis at a location outside the outer surface of the conduit coupler. Figure 4 and Figure 5 As shown, when the proximal circuit 114 is attached to the coupler 190, such traces 166, 176 can be confined in a plane having induction coils 116, 118, 120 on the circular portion 114 of the proximal circuit 110. Alternatively, if the connecting segments 132, 136 in which the connecting traces 166, 176 are located are non-planar (e.g., shaped for strain relief), then the traces 166, 176 can have a non-planar shape that follows the shape of the respective connecting segments 132, 136.

[0083] Circuit 110 includes a connecting segment 144 that joins a circular portion 114 to a rectangular portion 142 of the circuit. The connecting segment 144 may be flexible enough to bend from a planar shape to include a curve rotating at approximately 90°. Alternatively, during manufacture, circuit 110 may include a 90° curve in segment 144. When each induction coil 116, 118, 120 is separate, segment 144 may include three traces 166, 174, 176, each electrically connected to a corresponding induction coil 116, 118, 120 in the circular portion 114 of circuit 110. When two or more of coils 116, 118, 120 are electrically connected, segment 144 may include one or two traces.

[0084] The rectangular portion 142, directly connected to the circular portion 114, includes solder joints 168. With the three coils separated from each other, each corresponding extension 166, 174, and 176 engages with a separate solder joint 168. Alternatively, the extensions 166, 174, and 176 may engage two or more coils 116, 118, and 120, in which case fewer solder joints 168 may be included in the rectangular portion 142. With the coils 116, 118, and 120 separated from each other, the signal generated in each coil can be used to provide additional details of the force, such as an indication of eccentric force or the off-axis direction of the force.

[0085] The circular portions 114 of the distal circuit 180 and the proximal circuit 110 are sufficient to serve as distance measuring transducers, which, when assembled in the coupler 190, provide an electrical signal indicating the deflection of the coupler. The structural characteristics of the compressible frame 196 and the geometry of the catheter force probe can be known such that the deflection and / or compression of the compressible frame 196 are associated with the force or force vector applied to the catheter force probe.

[0086] A planar coil or trace for measuring position-related signals (i.e., a position coil or trace) may be incorporated into an additional rectangular portion 124, 134 of coil 110. Alternatively, if only force sensing is required, the rectangular portion 124, 134 with the coil may be omitted.

[0087] The left rectangular coil 128 can be combined with the left side portion 124, and the right coil 140 can be combined with the right side portion 134 (where right and left are relative to each other). Figure 5 (Illustrated orientation in the figure). Circuit 110 may include extensions 156, 154 positioned in a bonding segment 146 that bonds the left portion 124 to the central rectangular portion 142. Extensions 156, 154 connect the left rectangular coil 128 to a pad 168 in the central rectangular portion 142. Similarly, circuit 110 may include an extension positioned in the opposite bonding segment 148 that connects the right rectangular coil 140 to the pad 168. As shown, each coil 128, 140 on the rectangular portions 124, 134 comprises approximately five turns. However, because signal strength is a function of the number of turns, the number of turns can be maximized based on the dimensions of the rectangular portions 124, 134 and the pitch achievable by the photolithography process.

[0088] The winding of coils 116, 118, 120, 128, and 140 can be clockwise (i.e., with a clockwise orientation) or counterclockwise. The orientation of the coils can be selected as understood and appreciated by those skilled in the art to perform the sensor functions described herein.

[0089] The substrate 112 may be a single layer. Alternatively, the substrate 112 may include between two and ten layers, such as four layers. This allows the coils to be thickened by adding layers. However, the increased thickness of the layers can lead to an increase in the non-linearity of the signal generation. As another alternative, the circuit 110 may include additional portions (not shown), each of which includes one or more induction coils. The additional portions may each be connected to and positioned below the shown portions 114, 124, 134. The circuit 110 may have sufficient flexibility at the connection between the additional portion and the shown portion to bend 360° for placing the additional portion below the respective shown portions 114, 124, 134. For example, the tabs 126, 136, 150, 152 extending from the left rectangular portion 124 and the right rectangular portion 134 may be folded segments that engage with the additional left and right rectangular portions, each positioned below the shown left rectangular portion 124 and the shown right rectangular portion 134, respectively. The coils within the overlapping portions can be aligned. By stacking substrates, panel density can be increased due to the increase in area, and the yield of combined coils may not suffer from a nonlinear increase compared to coils stacked within the substrate.

[0090] Figure 8 This is a diagram of a circular circuit 180 that can be used as the distal circuit 180 of the spring assembly 100. Circuit 180 includes three larger portions 178 and two segments 186, as shown in the diagram. Figure 4 As shown and described. Each of the three larger portions 178 is a ring sector of circuit 180. Two of the ring sectors 178 are separated by openings 188 in circuit 180.

[0091] Segment 186 can be flexible, allowing circuit 180 to be opened for insertion into coupler 190 and as... Figure 4 The positioning is shown. The entire circuit 180 can be flexible. Alternatively, the annular sector 178 can be rigid, not substantially elastically deformable. Regardless of whether the annular sector 178 is rigid or flexible during manufacturing, when attached to the coupler 190, the annular sector 178 can be sufficiently rigid to hold the induction coil in the second plane P2 (see figure) during transport, pre-operation processing, and manipulation during processing. Figure 1 The segment 186 may be sufficiently flexible to allow circuit 180 to be mounted into coupler 190. The segment 186 may be rigidly attached to coupler 190. Alternatively, the segment 186 may be flexible to provide strain relief between annular sectors 178.

[0092] Circuit 180 can be opened, similar to Figure 6A and Figure 6B The circular portion 114 shown. Segment 186 can be shaped for strain relief, similar to... Figure 7 The connecting segments 132a and 136a shown are similar to those described with respect to the circular portions 114 and 114a.

[0093] Each annular sector 178 includes an induction coil 184. The coils 184 may be separate from each other, as shown, or they may each be connected to one or both of the other coils. As shown, each coil 184 includes approximately five turns. However, because signal strength is a function of the number of turns, the number of turns can be maximized based on the size of each segment and the pitch achievable by the photolithography process.

[0094] Each segment 186 may include a trace electrically connected to one or more of the induction coils 116, 120.

[0095] The distal circuit 180 may further include an extension 181 through which traces of the coil 184 can be routed. The extension 181 may be bent to extend longitudinally beyond the proximal end of the coupler 190 and ultimately to a solder joint (not shown). The extension 181 may be adhered to or otherwise joined to the proximal circuit 110 such that traces extending through the extension connect to solder joints 168 on the proximal circuit 110. Alternatively, the distal circuit 180 may include pad portions and / or additional induction coil portions, such as corresponding portions 142, 124, 134 of the proximal circuit 110. As another alternative, both the proximal circuit 110 and the distal circuit 180 may be configured substantially similar to [the previous configuration] when position sensing is not combined with a spring assembly. Figure 8 The exemplary distal circuit 180 shown has a solder joint connected to a trace in the extension 181.

[0096] Figure 9 and Figure 10 The catheter 14 is shown at two different steps of its components (see Figure 11 The diagram shows the components of a force probe including a spring assembly 100. Figure 9 A proximal flexible circuit 110 is shown assembled to coupler 190 and coupling sleeve 200. The circular portion 114 of the proximal circuit 110 and the distal circuit 180 are each adhered to coupler 190, as shown. Figure 1 and Figure 4 As shown.

[0097] like Figure 10As shown, the force probe may include a distal portion 18, which may include an ablation electrode 32 and a flushing port 214. The distal end 32 of the distal portion may be atraumatic. The force probe may also include a tubular proximal portion and a connecting sleeve 200, the connecting sleeve being sized to be positioned within an elongated catheter body 216 and shaped to allow rectangular portions 124, 134, 142 to be mounted thereon. The force probe may include a pair of planar induction coils attached between the proximal portion 200 and the atraumatic distal end 32, such that each coil in the pair lies in a plane perpendicular to the longitudinal axis LL. The force probe may include a compressible frame 196, which may be compressed parallel to the longitudinal axis to move the induction coils in the pair toward each other.

[0098] The force probe may also include a catheter coupler 190. The coupler may be attached to the spring assembly 100 via an engagement extension 194 extending from the distal end of the coupler 190. Protrusions 195 of the distal engagement extension 194 each engage complementary features of the tip 18. The coupler 190 may be attached to the tubular proximal portion 200 via an engagement extension 192 extending from the proximal end of the coupler 190. Protrusions 193 of the proximal engagement extension 192 each engage complementary features of the tubular proximal portion 200.

[0099] The conduit 14 may include a cable bundle 198 comprising a set of cables connected to the force probe, which, although not visible, are connected to solder joints 168 on the associated rectangular portion 142 of the proximal circuit 110, and thus to various coils or traces on the proximal circuit 110. The cable bundle 198 also includes cables connecting to traces of coils 184 of the distal circuit 180.

[0100] The rectangular portions 124, 134, and 142 of the near-side circuit 110 are directly adhered to or attached to the substantially flat surface 202 of the connecting sleeve 200 by means of an attachment to the underlying layered substrate of the surface 202. Assembled in this way, these portions 124, 134, and 142 of the flexible circuit 110 can be considered to have a triangular cross-section as observed in a plane AA perpendicular to the longitudinal axis LL. Connecting segments 146 and 148 can be adhered to the arcuate surface of the sleeve 200, which is positioned at the corner of the triangular cross-section of the flat portions 124, 134, and 142, as... Figure 9 As observed in plane AA shown in the figure.

[0101] Therefore, during assembly, the flexible circuit 110 can be easily inserted into the outer tube or sleeve 216. Figure 11In this conduit, the outer tube or sleeve provides the outer surface of the conduit 14 and defines the inner diameter in which the component portions of the conduit 14 (e.g., flexible circuits 110, 180, coupler 190, sleeve 200) are located. All components described herein are housed within a sleeve 216 of approximately 15 French or less. To help prevent soft spots beneath the sleeve 216 caused by gaps between the substantially flat outer surfaces of the rectangular portions 124, 134, 142 of the proximal circuit 110 on one side and by the curvature of the sleeve 216 on the other side, these gaps can be filled by including additional material (e.g., adhesive and polyimide layer) on the rectangular portions 124, 134, 142. The additional material may be manufactured separately from and adhered to the flexible circuit 110, or it may be an integrated portion of the flexible circuit 110 formed during the same photolithography process as the remainder of the flexible circuit 110.

[0102] The flexible circuit 110 can be assembled into the conduit 14 as follows. First, the flexible circuit 110 can be provided. If portions of the circuit 110 are folded to form a layered substrate, such portions can be folded accordingly. Adhesive can be applied to the annular sectors 160, 162, 164 and / or proximal mounting surfaces 204, 208, 222 of the coupler 190. The annular sectors 160, 162, 164 can be widened by flexing the connecting segments 132, 136 to increase the opening 122. Figure 6A and Figure 6B The annular sectors 160, 162, and 164 can be wedged into openings 232 in the tubular body of the coupler 190, defined by proximal mounting surfaces 204, 208, and 222 and struts 226 of the compressible frame 196. Connecting segments 132 and 136 can be bent and / or twisted as the annular sectors 160, 162, and 164 are moved into place. Once the sectors 160, 162, and 164 are in place, connecting segments 132 and 136 can relax to a stress-free shape. Adhesive can be cured to bond each annular sector 160, 162, and 164 of the proximal circuit 110 to the corresponding mounting surfaces 222, 208, and 204 of the coupler 190. When adhered to the coupler 190, the annular sectors 160, 162, and 164 can be coplanar. Adhesive can be applied to the back of the rectangular portions 124, 142, 134 and / or the connecting segments 146, 148 therebetween. The segment 144, to which the circular portion 114 of the near-side circuit 110 is attached to the portion 142 having the solder joint 168, can be bent at approximately 90°. The rectangular segments 124, 142, 134 can wrap around the coupling sleeve 200. The adhesive can be cured to attach the rectangular segments 124, 142, 134 and the connecting segments 146, 148 to the sleeve 200, as... Figure 9 and Figure 10 As shown.

[0103] Figure 11 This is an illustrated system 10 used to assess electrical activity on the heart 12 of a living subject and to perform ablation procedures on the heart. The treatment shown represents an example of the application in which the spring assembly 100 can be used as an intravascular force probe.

[0104] Figure 11 The system 10 shown includes a catheter 14, which is inserted by an operator 16 through the skin into a chamber or vascular structure of the heart 12 via the patient's vascular system. Typically, the operator 16, a physician, places the distal tip 18 of the catheter into contact with the heart wall, for example, at the target ablation site. Ablation can be performed on areas identified as abnormal, for example, by assessing cardiac electrical activity mapping, by applying thermal energy, for example, by conducting radiofrequency current through a wire in the catheter to one or more electrodes at the distal tip 18, which apply radiofrequency energy to the target tissue. The energy is absorbed in the tissue, heating it to a point where the tissue permanently loses its electrical excitability (typically above 50°C). This procedure creates non-conductive ablation foci in the cardiac tissue that disrupt abnormal electrical pathways leading to arrhythmias. This principle can be applied to different cardiac chambers to diagnose and treat a variety of different arrhythmias.

[0105] The catheter 14 may include a handle 20 with a suitable controller to enable the operator 16 to manipulate, position, and orient the distal end of the catheter as required for the ablation procedure. To assist the operator 16, the distal portion 18 of the catheter 14, or a portion adjacent to it, includes a spring assembly 100 that acts as a force sensor to provide feedback to the operator regarding the contact force (e.g., force vector) between the distal portion 18 and the tissue. The catheter 14 may also include a position sensor, such as a trace or coil (described below), which signals a processor 22 located in the console 24 to provide feedback regarding the position of the distal portion 18 relative to the patient's internal anatomy.

[0106] Ablation energy and electrical signals can be transmitted between the heart 12 and the console 24 via cable 38 through one or more ablation electrodes 32 located at or near the distal end 18. Pacing signals and other control signals can be transmitted from the console 24 to the heart 12 via cable 38 and electrodes 32.

[0107] The lead connector 35 links the console 24 to the surface electrode 30 and other components of the positioning subsystem for measuring the position and orientation coordinates of the catheter 14. Processor 22 or another processor may be an element of the positioning subsystem. Electrodes 32 and surface electrode 30 can be used to measure tissue impedance at the ablation site, as taught in U.S. Patent 7,536,218 to Govari et al., the entire contents of which are incorporated herein by reference, as fully set forth and appended to priority application US62 / 943,572. Temperature sensors (not shown), typically thermocouples or thermistors, may be mounted on or near each of the electrodes in electrode 32.

[0108] The console 24 typically includes one or more ablation power generators 25. The catheter 14 may be adapted to deliver ablation energy (e.g., radiofrequency energy, ultrasound energy, cryoenergy, and light energy generated by laser) to the heart using known ablation techniques. Such methods are disclosed in commonly assigned U.S. Patents 6,814,733, 6,997,924, and 7,156,816, the entire contents of which are incorporated herein by reference as fully set forth and appended to priority application US62 / 943,572.

[0109] The positioning subsystem may also include a magnetic positioning tracking arrangement that determines the position and orientation of catheter 14 by generating a magnetic field in a predefined workspace and using coils or traces disposed within the catheter (typically near the tip) to sense these fields at the catheter. Positioning subsystems are described in U.S. Patent 7,756,576 (the entire contents of which are incorporated herein by reference, as fully set forth in and appended to priority application US62 / 943,572) and the aforementioned U.S. Patent 7,536,218.

[0110] Operator 16 can observe and adjust the function of catheter 14 via console 24. Console 24 includes a processor, preferably a computer with appropriate signal processing circuitry. The processor is coupled to drive monitor 29. The signal processing circuitry typically receives, amplifies, filters, and digitizes signals from catheter 14, including signals generated by sensors such as electrical sensors, temperature sensors, and contact force sensors, and multiple position sensing coils or traces located distal to catheter 14. The digitized signals are received and used by console 24 and the positioning system to calculate the position and orientation of catheter 14, and to analyze electrical signals from electrodes and contact force sensors.

[0111] The console 24 may include an electrodiagnostic system comprising a processor and a memory having instructions in communication with the processor, which, when executed by the processor, cause the processor to receive a first electrical signal corresponding to a first distance between a first pair of induction coils 184, 116 in the spring assembly 100, receive a second electrical signal corresponding to a second distance between a second pair of induction coils 184, 118 in the spring assembly 100, receive a third electrical signal corresponding to a third distance between a third pair of induction coils 184, 120 in the spring assembly, and determine a three-dimensional force vector representing a force applied to the non-invasive distal end of the catheter 14, the force vector being determined at least in part based on the first, second, and third electrical signals.

[0112] The subject matter disclosed herein relates to structures including a spring assembly 100 within a catheter 14, which can be used to provide feedback to a user of an ablation catheter (e.g., an electrophysiologist) regarding forces applied to the tip of the catheter and any electrodes disposed thereon. Feedback may also include catheter position. These structures are located within a small inner diameter of the catheter (e.g., typically equal to or less than about 0.1 inches) but overcome various design constraints associated with them to reliably provide feedback. For example, a metal coil can be used to detect position within a magnetic field and / or relative position to another coil. Generally, larger and thicker coils with more turns are easier to detect than smaller and thinner coils with fewer turns, and the size of the coil is limited by the internal geometry of the catheter 14. Additionally, when such coils are fabricated as traces on a circuit board or flexible circuit via a photolithography process, the process limits the trace pitch. While this option can be used to increase the thickness of the circuit by adding layers via photolithography, this option has two drawbacks. First, it is expensive because manufacturing costs are proportional to the number of layers. That is, all else being equal, a flexible circuit with more layers costs more to manufacture than a flexible circuit with fewer layers. Second, the nonlinearity of yield is also proportional to the number of layers. That is, coil yield is compromised because the nonlinearity of yield increases with the number of traces. These design challenges are complicated by the inclusion of additional structures near the location traces, including flexible couplers 190 and flushing structures. Furthermore, crosstalk interference that may arise from packing the structures into a tight space should be considered. Therefore, ease of assembly and wiring is also necessary for both safety products and positive patient outcomes.

[0113] The description contained herein is an example of embodiments of the invention and is not intended to limit the scope of the invention in any way. As described herein, the invention contemplates many variations and modifications of the conduit, spring assembly, and force probe, including alternative materials for components, alternative geometries, alternative construction methods, and alternative methods of use. Modifications and variations that will be apparent to those skilled in the art based on the teachings of this disclosure are intended to fall within the scope of the appended claims.

Claims

1. A spring assembly, comprising: A tubular body extending along a longitudinal axis, the tubular body being sized to traverse a vascular system; A first mounting surface, comprising a first arcuate length partially surrounding the longitudinal axis and configured to engage a first circuit, is positioned within the tubular body, perpendicular to the longitudinal axis for a majority of the first arcuate length, and facing a first direction parallel to the longitudinal axis. A second mounting surface, comprising a second arcuate length partially surrounding the longitudinal axis and configured to engage a second circuit, is positioned within the tubular body, perpendicular to the longitudinal axis for most of the second arcuate length, and facing the first mounting surface in a second direction opposite to the first direction. A third mounting surface, comprising a third arcuate length partially surrounding the longitudinal axis and configured to engage a third circuit, is positioned within the tubular body, perpendicular to the longitudinal axis for most of the third arcuate length, and faces the first direction; A fourth mounting surface, comprising a fourth arcuate length partially surrounding the longitudinal axis and configured to engage a fourth circuit, the fourth mounting surface being positioned within the tubular body, perpendicular to the longitudinal axis for a substantial portion of the fourth arcuate length, and facing the second direction; A fifth mounting surface, comprising a fifth arcuate length partially surrounding the longitudinal axis and configured to engage a fifth circuit, the fifth mounting surface being positioned within the tubular body, perpendicular to the longitudinal axis for a substantial portion of the fifth arcuate length, and facing the first direction; A sixth mounting surface, comprising a sixth arcuate length partially surrounding the longitudinal axis and configured to engage a sixth circuit, the sixth mounting surface being positioned within the tubular body, perpendicular to the longitudinal axis for most of the sixth arcuate length, and facing the second direction; and A compressible frame that extends between the first mounting surface and the second mounting surface.

2. The spring assembly according to claim 1, further comprising: A first opening in the tubular body, the first opening being defined by the first mounting surface and the compressible frame; and A second opening in the tubular body, the second opening being defined by the second mounting surface and the compressible frame.

3. The spring assembly of claim 2, wherein the first opening and the second opening are at least partially collapsible in response to compression of the compressible frame.

4. The spring assembly according to claim 1, further comprising: One or more openings, defined by the compressible frame, which are at least partially collapsible in response to compression of the compressible frame.

5. The spring assembly according to claim 1, The first mounting surface, the third mounting surface, and the fifth mounting surface are coplanar in a first plane perpendicular to the longitudinal axis. The second mounting surface, the fourth mounting surface, and the sixth mounting surface are coplanar in a second plane perpendicular to the longitudinal axis. The third mounting surface and the fourth mounting surface face each other, and The fifth mounting surface and the sixth mounting surface face each other.

6. The spring assembly according to claim 1, A first opening in the tubular body, the first opening being defined by the first mounting surface and the compressible frame; A second opening in the tubular body, the second opening being defined by the second mounting surface and the compressible frame; A third opening in the tubular body, the third opening being defined by the third mounting surface and the compressible frame; A fourth opening in the tubular body, the fourth opening being defined by the fourth mounting surface and the compressible frame; A fifth opening in the tubular body, the third opening being defined by the fifth mounting surface and the compressible frame; A sixth opening in the tubular body, the third opening being defined by the sixth mounting surface and the compressible frame; and Three additional openings, each defined by the compressible frame.

7. The spring assembly according to claim 1, The first mounting surface, the second mounting surface, the third mounting surface, the fourth mounting surface, the fifth mounting surface, and the sixth mounting surface have substantially similar dimensions to each other. The first mounting surface, the third mounting surface, and the fifth mounting surface are spaced 120° apart from each other, as measured by rotation about the longitudinal axis. The second mounting surface, the fourth mounting surface, and the sixth mounting surface are spaced 120° apart from each other, as measured by rotation about the longitudinal axis.

8. The spring assembly according to claim 1, The first mounting surface includes a plurality of T-shaped notches thereon, and The second mounting surface includes a plurality of T-shaped notches thereon.

9. The spring assembly according to claim 1, further comprising: The first plurality of joining extensions extend from a first end of the tubular body in the first direction, each of the first plurality of joining extensions including a protrusion extending therefrom in a circumferential direction around the longitudinal axis. and The second plurality of joining extensions extend from the second end of the tubular body in the second direction, each of the second plurality of joining extensions including a protrusion extending therefrom in a circumferential direction around the longitudinal axis.

10. The spring assembly according to claim 9, The first plurality of engaging extensions consist of three protrusions, and The second plurality of joint extensions consists of three protrusions.

11. The spring assembly according to claim 1, further comprising: The first circuit is attached to the first mounting surface, and the first circuit includes a first induction coil; and The second circuit is attached to the second mounting surface, and the second circuit includes a second induction coil.

12. The spring assembly according to claim 1, further comprising: The first circuit is attached to the first mounting surface, and the first circuit includes a first induction coil; The second circuit is attached to the second mounting surface, and the second circuit includes a second induction coil; The third circuit is attached to the third mounting surface, and the third circuit includes a third induction coil; The fourth circuit is attached to the fourth mounting surface, and the fourth circuit includes a fourth induction coil. The fifth circuit is attached to the fifth mounting surface, and the fifth circuit includes a fifth induction coil; The sixth circuit is attached to the sixth mounting surface, and the sixth circuit includes a sixth induction coil; A first circuit segment extends on the outer surface of the tubular body and connects the first circuit to the third circuit. The second circuit segment extends on the outer surface of the tubular body and joins the third circuit to the fifth circuit. A third circuit segment extends on the outer surface of the tubular body and joins the second circuit to the fourth circuit. and A fourth circuit segment extends on the outer surface of the tubular body and joins the fourth circuit to the sixth circuit.

13. A vascular force probe, comprising: Proximal canal; The non-traumatic distal end, the proximal tube and the non-traumatic distal end define a longitudinal axis, and the force probe extends along the longitudinal axis; A first induction coil, the first induction coil including a first planar region and attached between the proximal tube and the non-invasive distal end, such that a majority of the first planar region is perpendicular to the longitudinal axis; A second induction coil, the second induction coil including a second planar region and attached between the proximal tube and the non-invasive distal end, such that a majority of the second planar region is perpendicular to the longitudinal axis; A third induction coil, the third induction coil including a third planar region, such that most of the third planar region is perpendicular to the longitudinal axis; A fourth induction coil, the fourth induction coil including a fourth planar region such that a majority of the fourth planar region is perpendicular to the longitudinal axis; A fifth induction coil, the fifth induction coil including a fifth planar region such that a majority of the fifth planar region is perpendicular to the longitudinal axis; A sixth induction coil, the sixth induction coil including a sixth planar region such that a majority of the sixth planar region is perpendicular to the longitudinal axis; and A compressible frame that can be compressed parallel to the longitudinal axis to move the first induction coil toward the second induction coil, the third induction coil toward the fourth induction coil, and the fifth induction coil toward the sixth induction coil.

14. The intravascular force probe according to claim 13, further comprising: A catheter coupler attached to the proximal tube and the non-invasive distal end, the catheter coupler including the compressible frame and structurally supporting the first induction coil and the second induction coil.

15. The vascular force probe according to claim 14, further comprising: A first connecting conductor electrically connected to the first induction coil extends circumferentially around the longitudinal axis and is positioned outside the outer surface of the conduit coupler.

16. The endovascular force probe of claim 13, wherein a majority of the first planar region, a majority of the third planar region, and a majority of the fifth planar region are located in a first plane, and a majority of the second planar region, a majority of the fourth planar region, and a majority of the sixth planar region are located in a second plane spaced apart from the first plane.

17. The vascular force probe according to claim 16, The compressible frame is also capable of bending to define a bend in the longitudinal axis, thereby causing the first plane and the second plane to be non-parallel.

18. The vascular force probe according to claim 13, further comprising: A generator, which is electrically connected to the first induction coil; and An electrical measuring tool, which is electrically connected to the second induction coil.

19. The vascular force probe according to claim 13, further comprising: An electrodiagnostic system, the electrodiagnostic system being configured to: Receive a first electrical signal corresponding to a first distance between the first induction coil and the second induction coil; Receive a second electrical signal corresponding to the second distance between the third induction coil and the fourth induction coil; Receive a third electrical signal corresponding to a third distance between the fifth induction coil and the sixth induction coil; as well as A three-dimensional force vector representing the force applied to the non-traumatic distal end is determined, the force vector being determined at least in part based on the first electrical signal, the second electrical signal, and the third electrical signal.

20. A catheter, comprising: Proximal canal; The non-traumatic distal end, the proximal tube and the non-traumatic distal end define a longitudinal axis; A first induction coil, the first induction coil including a first planar region and attached between the proximal tube and the non-invasive distal end, such that a majority of the first planar region is perpendicular to the longitudinal axis; A second induction coil, the second induction coil including a second planar region and attached between the proximal tube and the non-invasive distal end, such that a majority of the second planar region is perpendicular to the longitudinal axis; A third induction coil, the third induction coil including a third planar region, such that most of the third planar region is perpendicular to the longitudinal axis; A fourth induction coil, the fourth induction coil including a fourth planar region such that a majority of the fourth planar region is perpendicular to the longitudinal axis; A fifth induction coil, the fifth induction coil including a fifth planar region such that a majority of the fifth planar region is perpendicular to the longitudinal axis; A sixth induction coil, the sixth induction coil including a sixth planar region such that a majority of the sixth planar region is perpendicular to the longitudinal axis; and A compressible frame that can be compressed parallel to the longitudinal axis to move the first induction coil toward the second induction coil, the third induction coil toward the fourth induction coil, and the fifth induction coil toward the sixth induction coil; A catheter coupler attached to the proximal tube and the atraumatic distal end, the catheter coupler including the compressible frame and structurally supporting the first induction coil, the second induction coil, the third induction coil, the fourth induction coil, the fifth induction coil, and the sixth induction coil; and An elongated catheter fitting is attached to the proximal tube, surrounding the first induction coil, the second induction coil, the third induction coil, the fourth induction coil, the fifth induction coil, the sixth induction coil, the compressible frame, the catheter coupler, and extending to the proximal end of the catheter.

Images