Systems and methods including combined location verification agents - Patents.com

Abstract

Provided herein are systems and methods that include two or more localization agents coupled to one another by a linker. For example, provided herein are systems and methods for the placement of two or more coupled localization devices within a biological system and the detection of such localization devices for targeted surgery or other medical procedures. For example, provided herein are systems that include one or more miniature detectable devices that are coupled to one another and placed at a target location and activated by remote introduction of a magnetic field.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Provisional Application No. 63 / 078,971, filed on September 16, 2020, the content of which is incorporated herein by reference in its entirety.

[0002] The present specification provides systems and methods including two or more localization agents coupled to each other by a linker. For example, the present specification provides systems and methods for the placement of two or more coupled localization devices within a biological system and for the detection of such localization devices for targeted surgery or other medical procedures. For example, the present specification provides a system comprising one or more small detectable devices that are coupled to each other, placed at a target location, and activated by the remote introduction of a magnetic field.

Background Art

[0003] A common and serious problem for many medical procedures is the accurate localization of the treatment area. For example, the location of lesions such as tumors to be treated via a treatment including surgical resection continues to pose a problem to the medical community. Existing systems are expensive, complex, time - consuming, and often uncomfortable for patients.

[0004] Recent methods for tissue localization for medical procedures involve the use of localization agents such as RFID tags that can be placed within a patient. However, these tags may move within the patient between placement and the performance of the surgical procedure, resulting in the inability to properly mark the desired location within the patient. Furthermore, the orientation of the tag may shift after placement within the patient, resulting in a loss of accuracy in identifying the three - dimensional location of the tag within the patient. In larger patients, where the intensity of the signal generated by a single tag is insufficient to be detected due to the amount of tissue present, further problems in effectiveness may occur.

[0005] Therefore, improved systems and methods are needed for tissue positioning in medical procedures. [Overview of the Initiative] [Means for solving the problem]

[0006] This specification provides systems and methods comprising two or more location-finding agents (e.g., “tags”) linked together by a linker. For example, this specification provides systems and methods for the placement of two or more linked tags within a biological system and for the detection of such tags for targeted surgery or other medical procedures. The following description illustrates the invention using examples of human surgical procedures, but it should be understood that the invention is not limited in this respect and includes veterinary, agricultural, industrial, mechanical, military (e.g., sensing and removal of hazardous materials from a target or area), aerospace, and similar applications.

[0007] In some embodiments, the Specified provides a system comprising one or more of the following: a) at least two tags; b) linkers attached to each of the at least two tags; c) remote activation devices (e.g., exciter assemblies) that generate a magnetic field (e.g., a time-varying magnetic field) within the area of ​​each tag; and d) a plurality of sensors configured to detect signals from at least two tags when the tags are exposed to the magnetic field.

[0008] Each of at least two tags is attached (e.g., linked) to at least one other tag by the linker. Tags linked to each other by the linker are referred to herein as “linked tags”.

[0009] In some embodiments, the linker is a flexible linker. In some embodiments, the linker includes plastic. In other embodiments, the linker includes a shape memory alloy. For example, the linker may include a nickel-titanium alloy (e.g., Nitinol 60 or Nitinol 55).

[0010] In some embodiments, at least two tags are positioned to form an angle in the range of 15 to 40 degrees. In some embodiments, the angle is 25 degrees.

[0011] In some embodiments, the linker includes a grip that can be grasped by a surgical instrument. In some embodiments, the grip is spherical. In some embodiments, the linker is positioned within a package that includes a notch that exposes the grip.

[0012] In some embodiments, the linker includes a torsion spring. In some embodiments, each of the tags is attached to the linker via heat-shrink tubing.

[0013] In some embodiments, the linker is configured to hold at least two tags in a first position when the tags are present in the insertion device. In some embodiments, the linker is configured to hold at least two tags in a second position when they are present in tissue, wherein at least one of the tags in the second position points to approximately the X dimension and at least one of the tags points to approximately the Y dimension. In some embodiments, the at least two tags include first, second, and third tags. In such embodiments, when in the second position, i) the first tag points to approximately the X dimension, ii) the second tag points to approximately the Y dimension, and iii) the third tag points to approximately the Z dimension.

[0014] In some embodiments, the system further comprises a wire or line. The wire or line may be attached to and / or pass through the linker at two or more points on the linker. For example, the wire or line may be attached to and / or pass through the linker such that two or more tags are held in a first position relative to each other. The linker may be configured to hold two or more tags in a second position when the wire or line is not attached to and / or passes through the linker. The second position may be different from the first position.

[0015] In some embodiments, the tag is programmed to respond to a signal from a magnetic field at an offset frequency compared to the signal. In some embodiments, the tag includes a non-dielectric resonant antenna capacitor.

[0016] In some embodiments, each of at least two tags is equipped with an antenna, and each tag emits a sideband at a specified frequency when activated by a magnetic field. In some embodiments, each tag antenna is equipped with a coil antenna. For example, each coil antenna may be equipped with a ferrite core coil antenna.

[0017] In some embodiments, each coil antenna resonates at 100–200 kHz. Each coil antenna may resonate at the same or substantially the same frequency. Alternatively, each coil antenna may resonate at different frequencies.

[0018] In some embodiments, the remote activation device comprises at least one excitation coil. In some embodiments, the remote activation device comprises two or more excitation coils configured to carry current in either a clockwise or counterclockwise direction (for example, to ensure that the tag can be excited at multiple or any angle it may be placed at) so that the magnetic field generated by the remote activation device can be selectively generated in one or more of the X, Y, and Z directions. In some embodiments, the magnetic field is generated in two or more of the X, Y, and Z directions. In some embodiments, the magnetic field is generated in each of the X, Y, and Z directions.

[0019] In some embodiments, the remote activation device comprises four or more exciter coils. In some embodiments, the exciter coils are connected in series. In some embodiments, four of the exciter coils are in a two-row layout centered on coordinates (X1,Y1), (X1,Y2), (X2,Y1), and (X2,Y2). In some embodiments, the remote activation device (e.g., an exciter assembly) includes at least one of three current configurations: a) an exciter coil centered on (X2,Y1) and (X2,Y2) with all current flowing clockwise to simulate an exciter coil aligned perpendicular to the Z axis; b) an exciter coil centered on (X2,Y1) and (X2,Y2) with current flowing counterclockwise to simulate an exciter coil aligned to the X axis; and c) an exciter coil centered on (X1,Y2) and (X2,Y2) with current flowing counterclockwise to simulate an exciter coil substantially aligned to the Y axis. In some embodiments, the remote activation device includes all three of the above current configurations.

[0020] In some embodiments, the remote activation device (e.g., an exciter assembly) comprises multiple repeaters that provide a switching function to achieve a change in current direction (polarity) while maintaining the excitation frequency by switching additional capacitive reactance. In some embodiments, the switching function inserts additional series capacitive reactance through capacitive elements as the total inductance increases, so that the tuning center frequency is maintained at the excitation frequency (e.g., when four coils are used, the total inductance of the four coils changes as the current direction changes within each coil or coil pair). In some embodiments, the capacitive elements consist of multiple capacitors (e.g., to better accommodate the potential difference at resonance and / or to provide greater flexibility in frequency tuning). In some embodiments, the remote activation device further comprises a balun adjacent to the exciter coil. The balun removes common-mode current, otherwise the common-mode current would introduce an undesirable electric field component that could separately reduce accuracy. It also provides impedance matching to match the real component of the coil impedance to the real component of the transmission line, typically 50 ohms. In some embodiments, the balun has eight windings on the primary side (amplifier side) and four windings on the secondary side (coil side). In some embodiments, the system further comprises an amplifier in electronic communication state with a remote activation device. In some embodiments, the system further comprises a computer that controls magnetic field generation and sensor detection. In some embodiments, the computer comprises a search algorithm (embodied, for example, in software running on a processor) that adjusts the magnetic field orientation to identify (and power) the optimal detection of at least two tags.

[0021] Furthermore, this specification provides for the use of any of the above systems (for example, to detect the locations of two or more bound tags within an object, to detect the locations of two or more bound tags relative to a medical device, etc.).

[0022] Furthermore, provided herein are methods for identifying the locations of two or more coupled tags, the methods comprising the steps of: a) providing one of the systems described herein; b) placing at least two tags within a target; c) generating a magnetic field using a remote activation device; and d) identifying the locations of the tags within the target by collecting information emitted from each tag using an observation station. In some embodiments, this includes location or the relative location or distance of the tags to a medical device.

[0023] In some embodiments, the step of placing at least two tags within a target includes positioning at least two tags within the target using an introduction device. In some embodiments, at least two tags are positioned at a first position within the introduction device. In some embodiments, at least two tags move to a second position when placed within the target. In some embodiments, at least one of the tags at the second position points to approximately the X dimension, and at least one of the tags points to approximately the Y dimension. In some embodiments, the at least two tags include a first, second, and third tag, and when at the second position, i) the first tag points to approximately the X dimension, ii) the second tag points to approximately the Y dimension, and iii) the third tag points to approximately the Z dimension.

[0024] definition As used herein, the terms “processor” and “central processing unit” or “CPU” are used synonymously and refer to a device capable of reading a program from computer memory (e.g., ROM or other computer memory) and performing a set of steps according to that program.

[0025] As used herein, the terms "computer memory" and "computer memory device" refer to any storage medium readable by a computer processor. Examples of computer memory include, but are not limited to, RAM, ROM, computer chips, digital video discs (DVDs), compact discs (CDs), hard disk drives (HDDs), optical discs, and magnetic tapes. In certain embodiments, the computer memory and the computer processor are part of a non-transitory computer (e.g., within a control device). In certain embodiments, a non-transitory computer-readable medium is used, and the non-transitory computer-readable medium includes all computer-readable media with the sole exception of transitory propagation signals.

[0026] As used herein, the term "computer-readable medium" refers to any device or system for storing information (e.g., data and instructions) and providing it to a computer processor. Examples of computer-readable media include, but are not limited to, DVDs, CDs, hard disk drives, magnetic tapes, and servers for streaming media over a network, whether local or remote (e.g., cloud-based).

[0027] As used herein, the term "in an electronic communication state" refers to electrical devices (e.g., computers, processors, etc.) configured to communicate with each other either directly or through indirect signaling. Similarly, a computer configured to transmit information (e.g., data) to another computer or device (e.g., through cables, wires, infrared signals, telephone lines, broadcast waves, etc.) is in an electronic communication state with the other computer or device.

[0028] As used herein, the term "transmission" refers to the movement of information (e.g., data) from one location to another (e.g., from one device to another) using any suitable means.

[0029] As used herein, the term “alloy” refers to a combination of a metal and at least one other metal or nonmetal. The term “shape memory alloy” refers to an alloy that can be deformed when cooled but returns to its pre-deformed (e.g., “memorized”) shape when heated.

[0030] As used herein, the terms “subject” or “patient” refer to any animal (e.g., mammals), including but not limited to humans, non-human primates, pets, livestock, horses, rodents, and similar animals, that are receiving a particular treatment. Typically, the terms “subject” and “patient” are used synonymously herein in relation to human subjects.

[0031] As used herein, the term “subject / patient suspected of having cancer” refers to a subject who presents with one or more symptoms indicative of cancer (e.g., a prominent lump or mass) or who is undergoing cancer screening (e.g., during routine checkups). A subject suspected of having cancer may also have one or more risk factors. Subjects suspected of having cancer generally have not undergone cancer screening. However, “subject suspected of having cancer” includes individuals who have undergone an initial diagnosis (e.g., a CT scan showing a mass) but whose cancer stage is unknown. The term further includes individuals who have had cancer before (e.g., individuals in remission).

[0032] As used herein, the term “biopsy tissue” refers to a sample of tissue (e.g., breast tissue) that is removed from a subject for the purpose of determining whether the sample contains cancerous tissue. In some embodiments, the biopsy tissue is obtained because the subject is suspected to have cancer. The biopsy tissue is then examined (e.g., by microscopic examination, by molecular examination) for the presence or absence of cancer.

[0033] As used herein, the term “linker” refers to a suitable material for connecting one tag to another. A linker may include any suitable material. For example, a linker may include plastic. Alternatively, a linker may include a shape memory alloy.

[0034] As used herein, the term “combined tag” refers to a group of at least two tags, where at least one tag is attached to at least one other tag via a linker. The term may also refer to two attached tags. The term may also refer to three or more tags, where each tag is attached to at least one other tag via one or more linkers.

[0035] As used herein, the terms “tag” or “marker tag” refer to a small, embeddable marker that, when excited by the time-varying magnetic field of an exciter, emits a “homing beacon” spectrum of frequencies that are received by an observation coil and used to determine its location. It may be programmed to generate a unique spectrum, thus allowing multiple tags to be embedded and positioned simultaneously. [Brief explanation of the drawing]

[0036] [Figure 1] This figure shows an exemplary positioning of a patient with an exciter assembly, a medical device with display components attached, and a tag implanted next to a tumor. [Figure 2] This figure shows a mounting component 10 that is attached to a medical device 20 having a device tip 25, the mounting component 10 having two place emitters 70 inside, and the mounting component 10 is attached to or integrated with a display component 40. [Figure 3] This figure shows an example coil configuration for an exciter assembly. [Figure 4A] This figure shows an exemplary exciter assembly 250 attached to a controller 210 via a cable bundle 200. [Figure 4B] This figure shows an exemplary observation coil assembly (also known as an observation station assembly) 161. [Figure 4C] This figure shows an exemplary observation coil 160, including three directions in which the wire is wound to form a coil 167 on a metal magnetic core 166. [Figure 5] This figure shows an exemplary exciter assembly with four exciter coils (coils AD) in which current flows clockwise in all four exciter coils. [Figure 6] This figure shows an exemplary exciter assembly with four exciter coils (coils A and D) in which current flows clockwise in coils A and B and counterclockwise in coils C and D. [Figure 7] This figure shows an exemplary exciter assembly with four exciter coils (coils A and D) in which current flows clockwise in coils A and C and counterclockwise in coils B and D. [Figure 8] This figure shows an exemplary exciter assembly 250 with a top cover 230 attached, with the cable bundle 200 pulled inside. [Figure 9] This figure shows an exemplary attachment component 10, which has an angled distal end 300 into which the distal end 25 of a medical device 20 is inserted. [Figure 10]Figure 10A shows the distal end 25 of the medical device 20 after it has been initially inserted into the angled distal end 300 of the mounting component 10. Figure 10B shows the mounting component wire 60 before it is mounted to the cable management component 315 of the display component housing 330, and also shows the housing tapered connection 340 into which the proximal end tapered connection 350 of the mounting component 10 is inserted, and the cable management component 315 has two clips that are mounted on both the mounting component wire 60 and the medical device wire 50 and align them. [Figure 11] The figure shows an exemplary mounting component 10 mounted in a display component housing 330, the mounting component 10 having a pair of place emitters 70 coupled to a place emitter wire lead 72 located inside a tube 360, the mounting component also having an angled distal end 300 with a distal end opening 305 that allows the tip of a surgical device or other device to pass through and be inserted, and the display component housing 330 has a cable management component 315 consisting of a pair of clips for holding insulated wires. [Figure 12] The figure shows an exemplary mounting component 10 fitted into a display component housing 330 with a display component 40 placed inside, a display cover 370 used to secure the display component 40 to the inside of the display component housing 330 is shown, and an adhesive strip 380 that fits inside the mounting component and is shaped and sized to help secure a medical device to the mounting component is also shown. [Figure 13]Figure 13A shows the proximal end tapered connector 350 of a mounting component 10, which is configured to press into and fit into the housing tapered connector 340 of the display component housing 330. Figure 13B is a magnified view of area A in Figure 13A, which is part of the cable management component 315 and includes a cable management tapered connector 317 designed to be inserted into the tapered connector hole 319 of the display component housing 330, and the cable management tapered connector 317 includes a flat portion 318 for locking the angular position. [Figure 14] This diagram illustrates an exemplary system for locating a tag implanted in a patient. The system consists of an exciter assembly that emits a signal to activate the tag within the patient. The system electronics housing is shown as a movable cart that delivers signals to the exciter assembly and receives and processes signals from the tag within the patient. Guidance for the surgeon is displayed on a display component, as well as on a screen on the system electronics housing. [Figure 15] This figure shows an exemplary arrangement of two tags connected by a Nitinol linker. [Figure 16] This figure shows an exemplary arrangement of two tags connected by a wire or line, including a nitinol linker, crimp, and self-tightening washer. [Figure 17] This figure shows an exemplary arrangement of two tags linked by the linker. [Figure 18] This diagram shows the arrangement of Figure 17 within the package. [Modes for carrying out the invention]

[0037] This specification provides systems, devices, assemblies, and methods for locating two or more tags, for example, within the tissue of a patient, which are connected by a linker. For example, this specification provides systems, devices, and methods using one, more, or all of the following: a) two or more bound tags placed within an object such as a patient; b) a remote activation device that generates an electromagnetic field within the area of ​​the tags; c) a plurality of sensors (e.g., observation stations) that receive information from the tags exposed to the electromagnetic field; d) one or more emitters positioned on a medical device that are exposed to the electromagnetic field and emit information received by the sensors (e.g., observation stations); and e) a computer system for analyzing the information received by the sensors and generating and displaying information about the location of the medical device and / or one or more tags (e.g., relative location, relative distance, orientation, etc.).

[0038] The System, Device, Assembly, and Method meet the requirements for use in a variety of applications, including medical applications for placing bound tags within a subject. While this Specification focuses on medical applications in human tissue, it should be understood that the System and Method meet the requirements for a broader range of applications, including non-human applications (e.g., use in non-human animals such as livestock, pets, wild animals, or any veterinary environment). For example, the System may be used in environmental protection environments, agricultural environments, industrial environments, or similar. In some embodiments, the System, Device, Assembly, and Method meet the requirements for use in electromagnetic navigation systems that power remote tag devices using a sinusoidal magnetic field (see, for example, U.S. Patent No. 9,730,764, U.S. Patent Applications No. 15 / 281,862 and 15 / 674,455, which are incorporated herein by reference in their entirety).

[0039] In some embodiments, the Specified provides a system comprising at least two tags, each tag being attached to at least one other tag via a linker; a remote activation device that generates a magnetic field within the area of ​​each tag; and a plurality of sensors configured to detect signals from each tag while each tag is exposed to the magnetic field.

[0040] In some embodiments, the tag is wireless and ideally minimally sized. In some embodiments, while powered, the tag generates its own time-varying magnetic field at one or more sideband frequencies. The shape of the magnetic field is approximately the shape of a magnetic dipole located on the tag. The location of the tag is identified by monitoring the magnetic field at several locations using a receiving antenna coil, sensing coil, observation coil, or observation station, also called a sensor. In some embodiments, the system, device, assembly, and method further include an electrosurgical instrument. In some embodiments, the electrosurgical instrument, or components attached to or physically adjacent to the instrument, comprises two or more place emitters that similarly generate a magnetic field analogous to a magnetic dipole. In some embodiments, the place emitters are driven by two different frequency signals that differ from both the exciter frequency and the tag response frequency. In certain embodiments, the place emitters are wired to a signal source.

[0041] In some embodiments, a single exciter assembly is used to generate a signal that interacts with a tag and a location emitter in a mounting component associated with an electrosurgical instrument (e.g., as shown in Figure 4A). In some embodiments, the exciter assembly is contained within a single thin assembly. In some embodiments, the assembly comprising the exciter further comprises a sensor (e.g., a receiving antenna / sensing / observation station coil). In some embodiments, the exciter assembly is configured to be deployed beneath a patient undergoing a medical procedure. An exemplary procedure configuration is shown in Figure 1 with the patient 90 positioned on a surface 95 (e.g., a mattress or operating table). The surface 95 is held by a surface frame 97. The patient 90 has a lesion (e.g., a tumor) 110 and an implanted tag 100 positioned near, on, or within the tumor. The exciter assembly 250 is positioned directly beneath the patient and directly beneath the surface (e.g., on the surface frame 97), generating an electromagnetic field (not shown) in the area around the patient surrounding the location of the tag 100 and in the medical device 20 (e.g., surgical device) in the surgical field above the patient.

[0042] Figure 2 shows an exemplary electrocautery surgical device (e.g., BOVIE) that satisfies use in some embodiments of the present invention. The device 20 includes a tip 25 that provides a working surface for treating tissue, two embedded location emitters 70 that allow the system to sense the location and position of the device 20, and a display device 40 that provides visual information to the user (e.g., a surgeon) regarding the location of the tag in the patient.

[0043] In some embodiments, the exciter assembly is configured to provide enhanced detection of remote objects (e.g., tags and surgical devices) in several different environments where the absence of the exciter assembly would complicate location, position, and distance analysis, particularly real-time analysis of such factors.

[0044] In some embodiments, the system and method comprises multiple components. In some embodiments, the first component comprises at least two coupling tags (which may be used synonymously with the term “marker”) whose location, position, distance, or other characteristics are to be analyzed. The coupling tags described herein satisfy use in various systems and methods, such as those disclosed in WO2018031826A1, WO2017059228A1, WO2019236600A1, and WO2015112863A1, the entire content of each of those patents is incorporated herein by reference. In some embodiments, the system and method may include two coupling tags, three coupling tags, four coupling tags, five coupling tags, or six or more coupling tags. In some embodiments, the system and method includes two coupling tags. For example, the system and method may include two coupling tags “A” and “B” that are attached to each other via a linker. Alternatively, the system and method may include three or more coupling tags. In such embodiments, tags are linked in the sense that each tag is attached to at least one other tag via the same or different linker. For example, three tags may be linked, in which case tag "A" is attached to tag "B" via a linker, tag "B" is attached to tag "C" via a linker. In some embodiments, at least one tag may be attached to two or more tags. For example, three tags may be linked, in which case tag "A" is attached to tag "B", tag "B" is attached to tag "C", and tag "C" is attached to tag "A".

[0045] The tags are joined by a suitable linker. The linker may include any suitable material for connecting one tag to another. For example, the linker may include plastic. Alternatively, the linker may include a shape memory alloy. In some embodiments, the shape memory alloy linker may include any one or more metals selected from copper, iron, aluminum, nickel, titanium, manganese, silicon, zinc, or gold. For example, the shape memory alloy may be a nickel-titanium alloy (e.g., Nitinol). As another example, the shape memory alloy may be a copper-aluminum-nickel alloy. The metals in the shape memory alloy may be present in any suitable amount to achieve the desired alloy characteristics. For example, in the case of Nitinol, nickel and titanium are typically present in atomic percentages ranging from 55% to 60% nickel and 40% to 45% titanium (by weight). For example, Nitinol 55 contains 55% nickel and 45% titanium. Alternatively, Nitinol 60 contains 60% nickel and 40% titanium (by weight).

[0046] Referring to Figure 15, the first tag 500A and the second tag 500B are connected to a linker 504. The first tag 500A and the second tag 500B are glass tags mechanically connected to the linker 504 by heat shrink tubing 508 (or other similar retaining means). The linker 504 is made of nitinol wire and includes a torsion spring 512 positioned between the first tag 500A and the second tag 500B.

[0047] In some embodiments, the linker holds two or more binding tags in a first position before they are placed in an object, and the binding tags then form a second position after they are placed in the object. For example, the binding tags may first be held in a constrained position before being placed in an object so that they fit into an introduction device used to position the binding tags in the object. This can be achieved by using a plastic linker that bends or flexes to allow the binding tags to fit into the introduction device. Alternatively, this can be achieved using a shape memory alloy linker that can be refrigerated and molded into a first position to allow placement into an introduction device. For example, the first position may include a linear shape such that each of at least two tags is oriented linearly to fit into an introduction device (e.g., a cannula). The binding tags can then enter a second position after positioning in the object. For example, a shape memory alloy (e.g., Nitinol) linker may be bent again into a stored shape (e.g., L-shaped, T-shaped, V-shaped, etc.) after positioning in the object. As another example, the linker may be made of plastic that is bent or flexed to allow the binding tag to fit into the introduction device (e.g., a cannula), and the plastic linker may be unfolded during positioning within the object to allow the binding device to enter the second position. Alternatively, a shape memory alloy linker may be heated to the body temperature of the object during positioning within the object, thus allowing the alloy to return to its "memorized" shape.

[0048] The second position (e.g., the placement of the binding tag after positioning within the target) may be any preferred arrangement. For example, in embodiments with two binding tags, the second position may be L-shaped, T-shaped, V-shaped, or X-shaped. As another example, in embodiments with three or more binding tags, the second arrangement may be triangular, square, rectangular, or other shapes depending on the number of binding tags. Any of the above arrangements allows for improved fixation of the binding tag within the target tissue. In some embodiments, the binding tag is configured to be placed within the target at a surgical site or other clinically relevant location to mark a target area within the body.

[0049] In some embodiments, when in the second position, the tags are separated by an angle within the range of approximately 15° to approximately 40° (i.e., the tag separation angle). In some embodiments, the tags are separated by approximately 30° in the second position for improved 6-degree-of-freedom positioning. In some embodiments, the tags are separated by approximately 25° in the second position for improved 6-degree-of-freedom positioning. Advantageously, the tags are angled sufficiently large relative to each other to establish a full 6-degree-of-freedom coordinate system, while being angled sufficiently small relative to each other so that both tags can be powered simultaneously. A 0° angle between tags does not allow for the establishment of a full 6-degree-of-freedom coordinate system because the tag signal does not change as the tags are rotated around their major axes. Similarly, a 90° angle between tags is undesirable because when one tag is perfectly aligned to the exciter electric field and receives full power, the other tag does not receive power. A 90° angle between tags is also undesirable when one tag points to the center of another, as it makes it ambiguous when the entire structure is inverted (i.e., T has mirror symmetry while L does not).

[0050] In some embodiments, a second position may be achieved by the use of one or more additional accelerating features (e.g., wires, lines, crimps, washers, etc.). For example, at least two tags may be joined by a shape memory alloy. The linker and / or tags may be mounted on a wire or line further comprising crimps, washers, etc., to ensure that at least two tags achieve a desired arrangement. For example, the wire or line may include crimps, and the spacing between the crimps determines the angle at which at least two tags are joined (e.g., the angle of the shape memory alloy joining the tags). In some embodiments, the first position of at least two tags (e.g., arrangement within the introduction device) may be a straight line, and the wire / line may be pulled after the placement of the device into the object so that the crimps apply appropriate pressure to the joining tags / shape alloy, thus bending the alloy to achieve a desired second position within the object. In some embodiments, once the second position is achieved, the wire / line may be cut and subsequently removed from the object. Exemplary embodiments using these additional accelerating features are shown in Figure 16.

[0051] Referring to Figure 16, the first tag 600A and the second tag 600B are mechanically connected to the linker 604. The first tag 600A and the second tag 600B are glass tags held by clips 608 which are cut and formed into the linker 604. In the illustrated embodiment, the linker 604 is formed from a nitinol tube with a bend 612 which is cut and positioned between the first tag 600A and the second tag 600B. A wire 616 (or line) extends between the first end 620 and the second end 624 of the linker 604. In the illustrated embodiment, the wire 616 passes through holes formed in both the first and second ends 620, 624. Crimps 628A, 628B are positioned along the wire 616 to create position stops, and a self-tightening washer 632 is adjustablely positioned along the wire 616. The self-tightening washer 632 is configured to slide along the wire 616 to adjust the relative position of the first end 620 along the wire 616 with respect to the second end 624.

[0052] Referring to Figure 17, the first tag 700A and the second tag 700B are mechanically connected to the linker 704. The first tag 700A and the second tag 700B are held to the linker 704 by corresponding clips 708 formed on the linker 704. The linker 704 is a nitinol linkage with a bent portion 712 positioned between the first tag 700A and the second tag 700B. In the illustrated embodiment, the linker 704 includes a grip 716 at the first end 720 of the linker 704. In the illustrated embodiment, the grip 716 is a sphere configured to be graspable, for example, by surgical forceps. As such, the tags 700A, 700B and the linker 704 are easily manipulated by surgical instruments or devices.

[0053] Referring to Figure 18, the first tag 700A, the second tag 700B, and the linker 704 are positioned within a package 724 (sheath) for easy deployment to a bronchoscope, endoscope, or similar. The package 724 is configured to fit within the scope operating channel. Typically, the scope operating channel includes discontinuities, and the package 724 prevents the linker 704 and tags 700A, 700B from getting caught or snagged in those discontinuities. The package 724 is long enough to extend beyond the feature portion of the scope operating channel, but short enough not to extend where the operating channel bends into anatomical structures. In some embodiments, the package 724 includes lengths ranging from approximately 100 cm to approximately 180 cm. The package 724 surrounds the linker 704 (holding the linker 704 in a first position), except that the grip 716 is exposed. The grip 716 is grasped by the surgeon's forceps. In other words, the package 724 includes a notch 728 that exposes the grip 716. Once grasped, the forceps are used to push the tags 700A, 700B and the linker 704 toward the deployment site. Before reaching the deployment site, the tags 700A, 700B and the linker 704 are retractable until they are released in place. As such, the linker 704 is retractable if it encounters difficulties before being placed in place.

[0054] The use of at least two bonded tags offers advantages over the case of a single tag alone, in that fewer exciter electric field directions can be generated while still ensuring the orientation of at least one tag. Thus, the tags can be placed in the object in different orientations without risking the loss of detection of at least one of the two bonded tags. In some embodiments, the linker is configured to hold at least two tags in a second position when present in the tissue, where at least one of the tags in the second position points to approximately the X dimension and at least one of the tags points to approximately the Y dimension. In some embodiments, three tags are used, where, when in the second position, i) the first tag points to approximately the X dimension, ii) the second tag points to approximately the Y dimension, and iii) the third tag points to approximately the Z dimension.

[0055] Any suitable spacing between each of two or more binding tags may be used. For example, two or more binding tags may be spaced apart from each other at a suitable distance to allow the tags to mark a target area in the body (e.g., a tumor). In such embodiments, the suitable spacing between each of at least two tags may be determined based on the predicted size and shape of the target (e.g., a tumor). In some embodiments, the spacing between each of the binding tags is the same. In some embodiments, the spacing between two or more of the binding tags is variable (e.g., the distance between tags A and B may be different from the distance between tags A and C, or the distance between tags B and C). In some embodiments, the first and second tags are separated by at least approximately 2 mm to reduce the effects of cross-coupling.

[0056] In some embodiments, the second component comprises a remote activation device (e.g., an exciter assembly) that generates a magnetic field. In some embodiments, the second component is located within a device positioned near (e.g., below) an object containing a bound tag. In some embodiments, the third component comprises a plurality of sensors (e.g., an observation station) configured to receive signals generated by the tag when exposed to the magnetic field generated by the second component. In some embodiments, the second and third components are physically contained within the same device (e.g., as shown in Figure 4A). In some embodiments, the fourth component comprises a medical device location emitter. The fourth component may be integrated within the medical device or mounted on a mounting component (e.g., a sheath) or separately associated therewith. The fourth component comprises one or more location emitters (e.g., signal-emitting antennas, or other types of emitters) that generate signals via an electrical wire feed or upon exposure to the magnetic field generated by the second component, the signals being detectable by the third component. In some embodiments, the fifth component comprises a computing device having a processor that receives information from the observation station of the third component and generates information about the relative location, distance, or other characteristics of the tags, medical devices, and observation station. In some embodiments, the fifth component comprises a display that shows the information thus generated to the user of the system.

[0057] In some embodiments, the first component is two or more tags (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.). In some embodiments, the tags are of the same type. In other embodiments, the tags are of different types.

[0058] Any number of tag designs can be used. In some embodiments, at least one of the bonded tags contains or consists of an iron pellet or particle. When the iron object is introduced into the magnetic field, it creates an irregularity in the alternating magnetic field, which is detectable by a sense coil contained within the observation station and results in a phase and amplitude shift from the null. The null is recovered when the iron object is physically equidistant from the two sense coils.

[0059] In some embodiments, at least one of the coupled tags comprises a ferrite core coil antenna (e.g., resonating at 100–200 kHz) coupled to an integrated circuit (IC) powered by an AC magnetic field at resonance. In some embodiments, the core is contained within a housing (e.g., a cylindrical glass or plastic housing). In some embodiments, the exciter antenna is driven by a conventional oscillator and power amplifier at a level sufficient to power the tag. In some embodiments, the embedded tag amplitude modulates (AM) the continuous wave (CW) carrier power from the exciter, thus emitting sidebands at frequencies defined by a number programmed in the tag's counter. In some embodiments, these sidebands, as well as much stronger CW carriers, are ultimately detected by a third component.

[0060] In some embodiments, at least one of the coupling tags comprises a self-resonant object (e.g., a small ferrite core with a wound inductor). The wound inductor has inter-winding capacitance that, in combination with its inductance, creates a high-frequency resonant circuit. In some embodiments, at least one of the coupling tags comprises a resonant object (e.g., the self-resonant object is equipped with a chip capacitor to bring resonance at a specified frequency). In certain embodiments, the chip capacitor is a standard thin-film capacitor or a multilayer ceramic capacitor (MLCC) instead of a dielectric resonant antenna. Dielectric resonant antenna capacitors may not be well-suited for use in this method because they are not very effective at low frequencies (e.g., 100-200 kHz). In contrast, standard thin-film capacitors or MLCCs can be manufactured to have consistent functionality at low frequencies (e.g., 100-200 kHz). Furthermore, standard thin-film capacitors or MLCCs can be manufactured to provide consistent functionality independently of temperature, so that they operate effectively at both ambient temperature and body temperature (e.g., when placed within the object). In addition, standard thin-film capacitors or MLCCs are less expensive than dielectric resonant antennas.

[0061] In some embodiments, the tag comprises a resonant or self-resonant object with a diode. The diode, combined with an LC circuit, yields fractional harmonic frequencies when immersed in a magnetic field of sufficient strength (the applied voltage exceeds the diode's bandgap potential). In some embodiments, the tag comprises a resonant or self-resonant object with an active modulator (e.g., an integrated circuit amplitude modulates the resonant circuit). In some embodiments, detection occurs similarly to full-duplex (FDX) radio frequency identification (RFID), except that the modulation pattern is a simple fractional harmonic rather than a coded binary pattern, and in some embodiments, detection occurs after excitation, similar to a half-duplex (HDX) operating mode.

[0062] In some embodiments, at least one of the bound tags is configured for single use. In some such embodiments, the bound tags can be disabled or deactivated (e.g., like an EAS tag). This is particularly useful when multiple tags are used in a procedure, in which case individual tags are turned off to make detection of other tags easier (e.g., to avoid or reduce interference between multiple tags). In some embodiments, an energy burst from an external device is used to disable or deactivate the tags. In other embodiments, at least one of the bound tags has an internal control component that turns the tag on or off (e.g., the tag temporarily or permanently stops "talking") upon receiving a command from an external device.

[0063] In some embodiments, each of the binding tags has an outer length, width, and depth, where the length is 30 mm or less (e.g., 20 mm or less, ..., 10 mm or less, ..., 9 mm or less, ..., 8 mm or less, ..., 5 mm or less, ..., 3 mm or less, ..., etc.), the width is 5 mm or less (e.g., 4 mm or less, ..., 3 mm or less, ..., 2 mm or less, ..., 1 mm or less, ..., 0.5 mm or less, ..., etc.), and the depth is 5 mm or less (e.g., 4 mm or less, ..., 3 mm or less, ..., 2 mm or less, ..., 1 mm or less, ..., 0.5 mm or less, ..., etc.).

[0064] In some embodiments, each of the binding tags is contained within a housing or sheath. In some embodiments, no housing is used. In some embodiments, at least one of the binding tags is contained within a housing, and at least one of the binding tags is not contained within a housing. In some embodiments, the housing comprises a biocompatible material. In some embodiments, the housing provides a liquid and / or gas resistance barrier that isolates the signal source from the outside of the housing. In some embodiments, the housing is small and allows for administration of the binding tags through a needle, cannula, endoscope, catheter, or other medical device. In some such embodiments, the housing has an outer length, width, and depth, where the length is 30 mm or less (e.g., 20 mm or less, ..., 10 mm or less, ..., 9 mm or less, ..., 8 mm or less, ..., 5 mm or less, ..., 3 mm or less, ..., etc.), the width is 5 mm or less (e.g., 4 mm or less, ..., 3 mm or less, ..., 2 mm or less, ..., 1 mm or less, ..., 0.5 mm or less, ..., etc.), and the depth is 5 mm or less (e.g., 4 mm or less, ..., 3 mm or less, ..., 2 mm or less, ..., 1 mm or less, ..., 0.5 mm or less, ..., etc.). The housing may be of any desired shape. In some embodiments, the housing is cylindrical along its length axis. In some embodiments, the housing is shaped like a grain of rice (e.g., a cylinder with rounded ends). In some embodiments, the housing is shaped like a column (e.g., a cylinder with flat ends). In some embodiments, the housing is polygonal along its length axis (e.g., triangular, square, rectangular, trapezoidal, pentagonal, etc., in cross-section). In some embodiments, the housing has supports or other fasteners to keep the tag in place and prevent it from moving within the tissue. These supports may unfold upon placement in the tissue. In some embodiments, the fasteners may be made of a biocompatible material that adheres to the surrounding tissue. Advantageously, embodiments of two binding tags without a sheath can be positioned at a narrower bending radius.

[0065] In some embodiments, the housing is a single, uniform component synthesized around the internal components of the tag. In other embodiments, the housing consists of two or more separate regions that are sealed together after the introduction of the internal components of the tag. In some embodiments, the tag is fully or partially covered with a coating. In some embodiments, the coating comprises a biocompatible material (e.g., parylene-C).

[0066] In some embodiments, one or more of the coupled tags do not include any power source. In some embodiments, each of the coupled tags does not include any power source. For example, in some embodiments, the signal is generated from a signal source in response to a magnetic field as an activation event (i.e., electromagnetic induction).

[0067] In some embodiments, at least one of the coupled tags includes a radio frequency identification (RFID) chip (e.g., within a housing). For example, each coupled tag may include an RFID chip. In some embodiments, the RFID chip comprises a radio frequency electromagnetic field coil that modulates an external magnetic field to transfer an encoded identification number and / or other encoded information when queried by a reader device. In some embodiments, the RFID chip acts as a passive transponder to collect energy from an EM magnetic field generated by a second component (or other device) and then emit microwave or UHF radio waves. In some embodiments, the RFID chip is read-only. In other embodiments, it is read / write. The technology is not limited by the nature of the information provided by the RFID chip. In some embodiments, the information includes serial numbers, lot or batch numbers, time information (e.g., manufacturing date, surgery date, etc.); patient-specific information (e.g., name, family history, ingested medications, allergies, risk factors, procedure type, sex, age, etc.); procedure-specific information, etc. The technology is not limited by the frequency used. In some embodiments, RFID frequencies are in the 120–150 kHz band (e.g., 134 kHz), 13.56 MHz band, 433 MHz band, 865–868 MHz band, 902–928 MHz band, 2450–5800 MHz band, or similar. In some embodiments, the RFID chip is combined with browser-based software to enhance its effectiveness. In some embodiments, this software allows different groups, or specific hospital staff, nurses, and patients, to view real-time data associated with tags, procedures, or people. In some embodiments, the real-time data is stored and archived to leverage historical reporting functionality and to demonstrate compliance with various industry regulations. In some embodiments, the RFID chip reports sensor data (e.g., temperature, motion, etc.). In some embodiments, the RFID chip contains or collects information to be read later (e.g., post-surgery).In some embodiments, information is reviewed during surgery. For example, messages may be provided to the surgeon to help guide them (e.g., to optimize tumor removal with appropriate margins) (e.g., "the tip is just to the left of the tumor").

[0068] In some embodiments, each of two or more coupled tags consists of the same components. In other words, each coupled tag does not need to consist of components with different electrical properties in order for the tag to be uniquely identifiable. In some embodiments, each coupled tag consists of a signal source and housing, or a signal source, housing, and RFID chip, or substantially these. In some embodiments, the tag emits an ultrasonic signal (e.g., grayscale, spectral, or color Doppler) (e.g., via the chip) such that the signal is detectable by an ultrasonic probe or handheld Doppler device.

[0069] In some embodiments, the tag is heated during the procedure (e.g., by exposure to an external energy source). In some such embodiments, heating may be used to assist in tissue coagulation or precoagulation, or to provide thermotherapy (e.g., see U.S. Patent Publication 2008 / 0213382, which is incorporated herein in whole by reference). Heating may also be used to enhance the effects of radiotherapy.

[0070] In some embodiments, the second component provides a remote activation device. In some embodiments, the remote activation device comprises at least one excitation coil. In some embodiments, the remote activation device comprises two or more excitation coils (e.g., the exciter assembly shown in Figure 4A). In some embodiments, at least one excitation coil is provided on a base substrate. The base substrate may consist of any suitable material, which may be, for example, polycarbonate or similar, and is typically nonmagnetic and nonconductive.

[0071] In some embodiments, the excitation coil is provided within a patch or pad placed on the patient or on an operating table, but it can be positioned at any desired location within the functional distance of the tag. In some embodiments, the remote activation device provides an AC magnetic field derived from one or more exciter antennas. In some embodiments, when the system is used to locate a breast tumor, the patch is placed around the breast to be treated or separately near the breast. Similar techniques may be used for other target areas of the body. In some embodiments, the pad containing the excitation coil is placed directly beneath the patient. In such embodiments, a large coil or multiple coils are used. The excitation coil may comprise, or consist of, several windings of a planar conductor patterned on a dielectric substrate, or may comprise, or consist of, a magnetic wire wound around a suitable core, the coil is powered by an external frequency source, and the magnetic field emitted from the coil penetrates the patient's body to excite the tag, and its emission is detected by a detection component.

[0072] In some embodiments, one or more excitation coils are contained within a belt placed around the object or a portion of the object. In some embodiments, external excitation coils may be further used for other aspects of patient care, such as radiotherapy, or to act as ground current return pads used in electrosurgery. In some embodiments, the remote activation device emits light (e.g., laser light). In some embodiments, the remote activation device is configured for single use (e.g., disposable).

[0073] In some embodiments, the remote activation device uses unmodulated constant-frequency activation (i.e., the activation signal has a constant amplitude and frequency). In some embodiments, the remote activation device uses an unmodulated sweep frequency (i.e., the activation signal has a constant amplitude and sweep frequency between two endpoints). Such devices satisfy the need for use with resonant type tags, resulting in a detectable change in the amplitude of the activation signal when the transmitted frequency matches the resonant frequency of the tag. In some embodiments, the remote activation device uses a pulse frequency (i.e., the activation signal includes a short excitation pulse at a periodic frequency, which may consist of two closely related frequencies, the sum or difference of which is the response frequency of the tag). Pulse activation results in a post-pulse sinusoidal attenuation signal. The tag alters the characteristics of the attenuating signal, either in amplitude or time.

[0074] The system provided herein is advantageous in that each of at least two coupled tags can respond to a signal transmission frequency (e.g., an activation signal), such as an activation signal provided by a remote activation device. In other words, the transmission frequency is common to all tags. For example, each of at least two coupled tags can be programmed to generate an intrinsic frequency in response to a single transmission frequency provided by an activation device. The at least two coupled tags can be programmed to respond to a wide range of frequencies (e.g., 100–150 kHz), and the response frequency of each tag scales according to the stimulus frequency.

[0075] In some embodiments, the remote activation device comprises a handheld component. In some embodiments, the handheld component is lightweight (e.g., 5 kg or less, 4 kg or less, 3 kg or less, 2 kg or less, 1 kg or less, 0.5 kg or less, 0.25 kg or less, or any range in between, e.g., 0.5-5 kg, 1-4 kg, etc.) to allow the surgeon to hold and manipulate the component during the procedure. In some embodiments, the handheld component is shaped like a rod, having a proximal end held by the physician and a distal end directed toward the object or tissue to be treated containing the binding tag. In some embodiments, the handheld component is shaped like an otoscope, having a distal end terminating at an angle (e.g., at a right angle) from the body of the component. In some embodiments, the remote activation device comprises an antenna that generates a magnetic field. In some embodiments, the remote activation device has only a single antenna (i.e., monostatic). In some embodiments, the remote activation device has only two antennas (i.e., bistatic).

[0076] In some embodiments, the magnetic field of a remote activation device (e.g., the exciter assembly shown in Figure 4A) is controlled by a processor running a computer program. In some embodiments, the remote activation device includes a display or user interface that allows a user to control the remote activation device and / or monitor its functions during use. In some embodiments, the remote activation device provides visual, auditory, numerical, coded (e.g., arrows), character, or other output to assist the user in locating a bound tag or identifying the distance or direction from the remote activation device to the tag.

[0077] In some embodiments, the observation coils of the third component are configured to provide several antennas (e.g., observation antennas) collectively at several predetermined locations relative to the tags, and to receive signals generated by one or more tags when exposed to a magnetic field generated by the second component.

[0078] In some embodiments, each observation coil feeds a receiving channel that is time-division multiplexed (TDM) to reduce reception complexity. Fixed observation stations (e.g., arranged along a patient) at predetermined locations relative to each other and tags include one or more (e.g., one to three) observation coils arranged locally orthogonally to sense various components of the AC magnetic field from the tags. In some embodiments, one or more or all of these observation coils within an observation station are also TDM into the receiving channel to reduce complexity and crosstalk between antennas.

[0079] In some embodiments, the observation coil comprises or consists of a ferrite-filled cylindrical coil antenna (e.g., observation antenna) and is tuned for resonance at the frequency (e.g., 100–200 kHz) of the exciter (e.g., tag or emitter) (e.g., by one or more capacitors in parallel). Typical dimensions of the observation coil are 3–5 mm in diameter and 8–12 mm in length, but both smaller and larger dimensions can be used. In some embodiments, the observation station antenna has a ferrite core size of 0.635 × 2.54 cm (0.25 × 1 inch) and includes 75–80 turns of 10 / 46 (10 strands of #46) Litz wire, which provides 0.157 mH (Q=53) (75 turns).

[0080] In some embodiments, each observation coil is wound symmetrically around a ferrite core and connected to the secondary of a small balun transducer through one or two series capacitances per wire from the coil. The total series capacitance is selected to resonate with the inductance of the coil, and the turns ratio of the balun transducer may be selected to match the actual impedance of the resonant coil / capacitor circuit to the transmission line, typically 50 ohms. The actual impedance of the resonant coil / capacitor circuit is typically 10 to 25 ohms, but can vary from just a few ohms to over 50 ohms and can be appropriately matched by the appropriate selection of the primary and secondary turns of the balun transducer. In addition to its role as an impedance transducer, the balun can be considered to minimize any electric field generation / magnetic susceptibility from the observation coil assembly, and alternately, it can be considered to eliminate common-mode effects.

[0081] In some embodiments, each observation station includes one to three observation antennas oriented orthogonally to one another and further arranged to have minimal crosstalk (i.e., interference with one another). The components housing the observation stations further include one or more receiving channels for collecting information acquired by the antennas of the observation stations. In some embodiments, the receiver has or comprises one or more channels, each channel being fed (via a multiplexing switch) by one or more observation antennas.

[0082] In some embodiments, the observation station is provided beneath the patient (e.g., within a pad, clothing, or other device positioned beneath the patient). In some embodiments, the observation station is integrated into the operating table or imaging device on which the patient is placed during the medical procedure. In some embodiments, the observation station is located on the floor, wall, or ceiling of the operating room, or inside a medical transport vehicle. In some embodiments, the observation station is integrated into or attached to a medical device used in the medical procedure.

[0083] In some embodiments, a fourth component provides a medical device location emitter (see Figures 9–12) within a wearable component to enable the system to determine the location, position, distance, or other characteristics of the medical device relative to one or more tags. In some embodiments, one or more medical device location emitters are integrated within the medical device or within a wearable component. In other embodiments, they are wearable on the medical device. In some such embodiments, the location emitter is provided within a wearable component (e.g., a sleeve) that slides over a portion of the medical device. The location emitter may and / or may be made of the same material as the tag, but is located on or near the medical device rather than within the tissue. For example, in some embodiments, the emitter comprises a coil excited by both a carrier and / or a sideband, enabling the emitter to emit a signal as if it were a tag. In other embodiments, the location emitter is wired to a power supply and a signal source.

[0084] In some embodiments, the location of the emitter is geometrically achieved by measuring quasi-simultaneous power detected from the emitter at multiple observation stations (e.g., four or more stations) and performing a vector operation using the power difference to determine the emitter's location without ambiguity. This process is facilitated by preliminary calibration using known tags at known locations prior to the procedure.

[0085] In some embodiments, a component including a location emitter (e.g., a wearable component) may further comprise a display to assist the user in orienting the medical device toward the binding tag during a surgical procedure. In some such embodiments, a visual or audible display is provided on or associated with a medical device that receives location information about one or more of the binding tags from a computer system. The display may be one or more directional indicators, such as LEDs, indicating direction and / or distance to the tag. Color changes may be used to indicate “on-target” versus “off-target” positions. In certain embodiments, the display comprises a first display for presenting distance information to the tag (e.g., visual, audible, light, color, vibration, tactile, etc.); a second display for presenting vertical axis orientation (e.g., visual, audible, light, color, vibration, tactile, etc.), such as a preset preferred angle for approaching the binding tag in the patient; and / or a third display for presenting horizontal orientation (e.g., left-right information, so that the surgical device can be centered when approaching the tag). In some embodiments, the display comprises multiple displays (e.g., visual, audible, sensory, etc.) that enable the use of the correct pitch and yaw axis (to minimize damage to non-target tissue), as well as / or further displays that provide distance information to the tag. In certain embodiments, a series of lights and / or sounds are provided on the display to guide the surgeon (e.g., the surgeon attempts to keep a light in the center of a series of "X" lights and / or keep the volume of the warning sound off or as low as possible).

[0086] Vectors describing the location of a location emitter are used to provide surgeons with visual guidance regarding the spatial relationship of a medical device (e.g., particularly its tip) to an implanted tag or (e.g., with computer guidance) to a lesion boundary. The use of multiple location emitters on a mounting component attached to a medical device provides vectors to determine the device's principal axis using the same vector calculations. When more complex medical devices are used, such as robotic surgical systems (e.g., the da Vinci surgical system), multiple location emitters located at multiple different locations on the device are used to provide location, orientation, and other positional information for multiple components of the device (e.g., arms). In some embodiments, location emitters are also used as detectors (e.g., to provide observation stations on a medical device).

[0087] In some embodiments, a fifth component provides one or more computing systems comprising one or more computer processors and appropriate software for analyzing, calculating, and displaying tag and emitter position information (see component 210 in Figure 4A). In some embodiments, the display provides a graphic representation of the tag, patient, and / or medical device on a monitor. In other embodiments, the display provides directional information for moving or positioning the medical device. In some embodiments, the system automatically controls the medical device or one or more functions thereof (e.g., by robotic control). In some embodiments, the display integrates the tag and / or medical device information with previously acquired or simultaneously acquired medical images of the patient or target tissue (e.g., CT, MRI, ultrasound, or other imaging methods). For example, in some embodiments, images showing one or more tags are fused with images of the target tissue or body region acquired from the imaging device. In some embodiments, the information is analyzed in real time. In some embodiments, the information is analyzed at one or more separate time points.

[0088] In some embodiments, a fifth component provides command and control functions for the user of the system. In some embodiments, the fifth component stores information that helps guide the information displayed on the attachment component. For example, the information may include data on the type of medical device to which the attachment component is attached, or on which tips or cutting instruments are used with a particular medical device. In this regard, the precise location of the cutting tip of the medical device and its relationship to a tag (e.g., distance to the tag) is communicated to the surgeon (e.g., for very precise instructions regarding the tissue to be cut). Such information may, for example, be manually entered by the user into the control unit or attachment component by the user in some embodiments, or it may be automatically discovered when the detection component is attached to a particular medical device (e.g., by a barcode or other indicator).

[0089] This system is suitable for use with a variety of medical devices and procedures. In some embodiments, the surgical device comprises an electrosurgical device that can be turned on and off by the user, and a control unit, which is part of a fifth component, allows the remote activation device to generate a magnetic field when the electrosurgical device is off and prevents the remote activation device from generating a magnetic field when the electrosurgical device is on (for example, to ensure that the surgical device and the detection system do not interfere with each other). In other embodiments, the surgical device comprises a power cord, an AC current clamp attached to the power cord, the AC current clamp electrically or wirelessly coupled to the control unit, the AC current clamp senses when the electrosurgical device is on or off and reports this to the control unit (for example, as a result the control unit can ensure that the magnetic field from the surgical device and the magnetic field from the remote activation device are not activated simultaneously).

[0090] In certain embodiments, the surgical device includes an electrocautery device, a laser cutting device, a plasma cutting device, or a metal cutting device (e.g., a surgical device manufactured by BOVIE MEDICAL). Additional examples of medical devices that satisfy use in embodiments of this system include, for example, the following U.S. Patents: No. 9,144,453, No. 9,095,333, No. 9,060,765, No. 8,998,899, No. 8,979,834, No. 8,802,022, No. 8,795,272, No. 8,795,265, No. 8,728,076, No. 8,696,663, No. 8,647,342, No. 8,628,524, No. 8,409,1 These are found in Nos. 90, 8,377,388, 8,226,640, 8,114,181, 8,100,897, 8,057,468, 8,012,154, 7,993,335, 7,871,423, 7,632,270, and 6,361,532, all of which are incorporated herein by reference in their entirety and in particular with respect to the handheld medical devices disclosed herein.

[0091] In some embodiments, the attachment component has, or is attached to, a display component for orienting the surgeon toward one or more tags. In some embodiments, the display component provides i) a spatial orientation indicator (e.g., visual, audible, etc.) and / or ii) a distance indicator to the tag (e.g., visual, audible, etc.). In some embodiments, the display component comprises a first display for presenting distance information to the tag (e.g., visual, audible, light, color, vibration, touch, etc.); a second display for presenting vertical axis orientation (e.g., a visual, audible, light, color, vibration, touch, etc. display), such as a preset preferred angle for approaching the tag in the patient; and / or a third display for presenting horizontal orientation (e.g., left-right information, so that the surgical device is centered when approaching the tag). In some embodiments, the display component comprises multiple displays (e.g., visual, audible, sensory, etc.) that enable the use of the correct pitch and yaw axes (to minimize non-target tissue damage), and / or further displays that provide distance information to the tag. In certain embodiments, the medical device is moved around the patient's body before the surgeon orients the emitter and display components. In certain embodiments, a series of lights and / or sounds are provided on the display components to guide the surgeon (for example, the surgeon attempts to keep a light in the center of a series of "X" lights and / or keep the volume of an alert sound off or as low as possible).

[0092] The binding tags disclosed herein are not limited to placement within specific body regions, body parts, organs, or tissues. For example, in some embodiments, the tags are placed in the head, neck, chest, abdomen, pelvis, upper limbs, or lower limb body regions. In some embodiments, the tags are placed within organ systems such as the skeletal system, muscular system, cardiovascular system, digestive system, endocrine system, cutaneous system, urinary system, lymphatic system, immune system, respiratory system, nervous system, or reproductive system. In some embodiments, the tags are placed within organs. Such organs may include the heart, lungs, blood vessels, ligaments, tendons, salivary glands, esophagus, stomach, liver, gallbladder, pancreas, intestines, rectum, anus, hypothalamus, pituitary gland, pineal gland, thyroid gland, parathyroid gland, adrenal gland, skin, hair, fat, nails, kidneys, ureters, bladder, urethra, pharynx, larynx, bronchi, diaphragm, brain, spinal cord, peripheral nervous system, ovaries, fallopian tubes, uterus, vagina, mammary glands, testes, vas deferens, seminal vesicles, and prostate gland. In some embodiments, the tag is placed within tissues such as connective, muscle, nerve, and epithelial tissue. Such tissues may include cardiomyocytes, skeletal muscle tissue, smooth muscle tissue, loose connective tissue, dense connective tissue, reticular connective tissue, adipose tissue, cartilage, bone, blood, fibrous connective tissue, elastic connective tissue, lymphocyte connective tissue, areolar connective tissue, simple squamous epithelium, simple cuboidal epithelium, simple columnar epithelium, stratified epithelium, multifidous epithelium, and transitional epithelium.

[0093] In some embodiments, the tissue region in which the tag is located includes a lesion. In some embodiments, the lesion is a tumor or a tissue region identified as being at risk of forming a tumor. For example, one tag may be placed at the boundary of a tumor, and another tag at a secondary boundary of the tumor, so that the binding tag delineates the outer edge of the tumor. In some embodiments, the lesion is fibrous tissue. In some embodiments, the lesion is an inflamed or infected area. In some embodiments, the tag is placed in a lumen to detect organ function or other processes or to provide location information. For example, the tag may be swallowed or placed in a hollow organ via endoscopy. In some embodiments, the tissue region is healthy tissue. In some embodiments, two binding tags are positioned offset from the lesion. In some embodiments, two binding tags are positioned within the airway up to approximately 5 mm.

[0094] In some embodiments, the binding tag is placed within a solid tumor. Examples of solid tumors to which the tag may be placed include aberrant basal cell carcinoma, acinar cell tumor, acinar cell carcinoma, adenocarcinoma, adenoid cystic carcinoma, adenoid / pseudoadenoid squamous cell carcinoma, adnexal neoplasm, adrenocortical adenoma, adrenocortical carcinoma, apdoma, basal cell carcinoma, basaloid squamous cell carcinoma, carcinoid, cholangiocarcinoma, scarring basal cell carcinoma, clear cell adenocarcinoma, clear cell squamous cell carcinoma, mixed small cell carcinoma, comedone carcinoma, compound epithelial carcinoma, cystadenocarcinoma, cystadenoma, cystic basal cell carcinoma, cystic neoplasm, ductal carcinoma, endometrioid tumor, epithelial neoplasm, extramammary Paget's disease. Familial adenomatous polyposis, Pincus's fibroathematous tumor, gastrinoma, glucagonoma, Gravitz tumor, hepatocellular adenoma, hepatocellular carcinoma, hidrocystoma, Haasle cells, invasive basal cell carcinoma, insulinoma, intraepidermal squamous cell carcinoma, invasive lobular carcinoma, inverted papilloma, keratoacanthoma, Kratzkin's tumor, Krukenberg's tumor, large cell keratinizing squamous cell carcinoma, large cell nonkeratinizing squamous cell carcinoma, plastic gastritis, liposarcoma, lobular carcinoma, lymphoepithelial carcinoma, ductal carcinoma, medullary carcinoma, medullary carcinoma of the breast, medullary carcinoma of the thyroid, nodules Basal cell carcinoma, plaque scleroderma type basal cell carcinoma, sclerosing basal cell carcinoma, mucinous carcinoma, mucinous cystadenocarcinoma, mucinous cystadenoma, mucoepidermoid carcinoma, multiple endocrine neoplasia, neuroendocrine neoplasia, nodular basal cell carcinoma, oncocytoma, osteosarcoma, ovarian serous cystadenoma, Paget's disease of the breast, pancreatic ductal carcinoma, pancreatic serous cystadenoma, papillary carcinoma, papillary sweat adenoma, papillary serous cystadenocarcinoma, papillary squamous cell carcinoma, pigmented basal cell carcinoma, polypoid basal cell carcinoma, poroid basal cell carcinoma, prolactinoma, pseudomyxoma peritonei, renal cell carcinoma, renal plunge cell tumor This includes carcinomas, lymphomas, and sarcomas, including but not limited to erythematous ulcers, serous carcinoma, serous cystadenoma, signet ring cell carcinoma, signet ring cell squamous cell carcinoma, cutaneous adnexal tumors, small cell carcinoma, small cell keratinizing squamous cell carcinoma, somatostatinoma, spindle cell squamous cell carcinoma, squamous cell carcinoma, squamous cell lung cancer, squamous cell thyroid cancer, superficial basal cell carcinoma, superficial multicentric basal cell carcinoma, papillary syringoid cystadenoma, syringoma, thymoma, transitional cell carcinoma, wart-like carcinoma, wart-like squamous cell carcinoma, vipoma, and Warthin tumor.

[0095] In some embodiments, placing a binding tag involves the steps of inserting an introduction device into a target and introducing the binding tag into the target through the introduction device. In some embodiments, the introduction device is a needle, cannula, or endoscope. In some embodiments, the binding tag is pushed through the introduction device (e.g., by physical force, pressure, or any preferred technique) and released into the target at the distal end of the introduction device. After the tag is placed, the introduction device is withdrawn, leaving the tag in the desired position with respect to the target. In some embodiments, the introduction of the tag is guided by imaging techniques. In some embodiments, the binding tag is positioned within a package while being moved to a desired position.

[0096] In embodiments provided herein, multiple tags are placed within a target area. The tags are linked together (e.g., by a linker). The tags may be of the same type or may be different (e.g., different signal types). The tags may be placed close to each other or far apart. In some embodiments, the multiple tags may be used to triangulate a location intended for medical intervention.

[0097] In some embodiments, the tags are further used as references for radiotherapy (or other targeted therapies). The location of the tag is identified by an external reader, which is used, for example, to direct a laser beam onto the skin surface where the tip is located. This eliminates the need to use X-rays, CT scans, or fluoroscopy to view the reference. This also reduces or eliminates the need to place skin markers (e.g., tattoos) on the patient. This also helps with respiratory compensation as the reference moves up and down with the tumor in the lung or abdomen. Thus, real-time radiation can be performed only when the tumor is in the correct location, reducing damage to background tissue (e.g., avoiding burning longitudinal stripes in the patient as the tumor moves up and down). Use as a reference for waveguide therapy (e.g., radiotherapy) also improves triangulation as depth information (based on signal intensity) helps locate the tumor to minimize collateral damage.

[0098] In some embodiments, the Specified provides systems and methods using one, more, or all of the following: a) two or more coupled tags (e.g., comprising antennas; e.g., coil antennas; e.g., ferrite core coil antennas; e.g., antennas coupled to an integrated circuit; e.g., antennas resonating at 100-200 kHz); b) a remote activation device that generates a magnetic field within the area of ​​the tags; and c) a plurality of sensors (e.g., observation stations), each of which has an antenna configured to detect information generated by the tags or changes in the magnetic field generated by the remote activation device caused by the tags. In some embodiments, at least one of the coupled tags emits a sideband at a predetermined frequency upon magnetic field activation, and the observation station detects such a sideband. In some embodiments, at least one of the coupled tags emits a sideband at a frequency determined by a number programmed into a counter within the tag.

[0099] In some embodiments, the remote activation device comprises an excitation coil powered, for example, by a generator electrically connected to the remote activation device. In some embodiments, the remote activation device comprises a pad configured to be placed in close proximity to the patient (e.g., below, above, or to the side) having a binding tag implanted within the patient. In some embodiments, the pad also includes an observation station.

[0100] In certain embodiments, the Specified Provisions Provide a device and system comprising a remote activation device that generates a magnetic flux within the area of ​​a tag, the remote activation device comprising a) a base substrate, b) at least one exciter coil mounted on the base substrate that generates the magnetic flux, and c) a plurality of observation station assemblies mounted on the base substrate, each observation station assembly comprising an observation coil having a sensing axis and comprising i) a core containing metal, having a coilless proximal end, a coilless distal end, and a central region, and ii) a coil winding wound around the central region of the core, each observation station assembly being oriented on the base substrate such that the sensing axis of each observation coil extends A) from the proximal end to the distal end of the core, and B) perpendicular to, or substantially perpendicular to, the magnetic flux and / or ii) at least one exciter coil. In certain embodiments, the at least one exciter coil is configured to selectively carry current in a clockwise or counterclockwise direction. In other embodiments, each sensing axis of the observation coil is substantially perpendicular to the magnetic flux in both clockwise and counterclockwise directions.

[0101] In certain embodiments, each of the exciter coils has a central plane, and each of the observation station assemblies is further oriented on a base substrate such that the sensing axis of each of the observation coils is coplanar with the central plane of each of the exciter coils. In certain embodiments, the magnetic flux does not induce a signal in the observation coil when it is generated substantially in the X and / or Y directions.

[0102] In other embodiments, each observation station assembly further comprises i) first and second observation coil brackets, and ii) first and second elastomer components, wherein the coilless proximal end of the magnetic core is fixed between the first observation coil bracket and the first elastomer component, and the coilless distal end of the magnetic core is fixed between the second observation coil bracket and the second elastomer component. In further embodiments, each of the first and second observation coil brackets comprises at least one adjustment component. In other embodiments, the at least one adjustment component comprises at least one screw and / or at least one rod. In certain embodiments, this specification provides a method for using adjustment components to adjust the observation coils such that their sensing axes are perpendicular or substantially perpendicular to the magnetic flux and / or at least one exciter coil.

[0103] In some embodiments, at least one adjustment component allows each sensing axis of the observation coil to be adjusted so that it is perpendicular or substantially perpendicular to the magnetic flux in one or more of the X, Y, or Z directions. In some embodiments, each sensing axis of the observation coil may be adjusted so that it is perpendicular to the X and Y directions. In further embodiments, the magnetic flux may be further generated selectively substantially in the Z direction, and each of the observation station assemblies is oriented on the base substrate so that each sensing axis of the observation coil is perpendicular or substantially perpendicular to the magnetic flux Z direction. In further embodiments, the magnetic flux does not induce a signal in the observation coil when generated substantially in the Z direction. In further embodiments, at least one adjustment component allows each sensing axis of the observation coil to be adjusted so that it is perpendicular or substantially perpendicular to the magnetic flux in each of the X, Y, and Z directions. In some embodiments, the metal includes ferrite.

[0104] In other embodiments, each observation station assembly is oriented on the base substrate such that the sensing axis of each observation coil is perpendicular or substantially perpendicular to at least one exciter coil. For example, each observation station assembly may be oriented on the base substrate such that the sensing axes are perpendicular or substantially perpendicular to at least two exciter coils, at least three exciter coils, or at least four exciter coils. In some embodiments, each observation station assembly is oriented on the base substrate such that the sensing axis of each observation coil is perpendicular or substantially perpendicular to the magnetic flux in each of the X and Y directions. In further embodiments, four or more exciter coils are four exciter coils or six exciter coils. In other embodiments, the four exciter coils are in a two-row layout centered on coordinates (X1,Y1), (X1,Y2), (X2,Y1), and (X2,Y2). In an additional embodiment, the remote activation device includes three current configurations: a) an exciter coil centered at (X2,Y1) and (X2,Y2) with all current flowing clockwise to simulate an exciter coil aligned or substantially aligned with a plane perpendicular to the Z axis; b) an exciter coil centered at (X2,Y1) and (X2,Y2) with current flowing counterclockwise to simulate an exciter coil aligned or substantially aligned with the X axis; and c) an exciter coil centered at (X1,Y2) and (X2,Y2) with current flowing counterclockwise to simulate an exciter coil aligned or substantially aligned with the Y axis.

[0105] In some embodiments, the sensing axis of the observation coil is substantially right-angled when the separation between at least four exciter coils and the observation coil is 60 dB or more in the X and Y directions. In other embodiments, the sensing axis of the observation coil is substantially right-angled when the separation between at least four exciter coils and the observation coil is 60 dB or more in the X, Y, and Z directions.

[0106] In certain embodiments, the Specified Provisions Provided are systems and devices comprising an exciter assembly that circulates to generate at least first, second, and third magnetic fields (e.g., first, second, third, fourth, fifth, sixth, seventh, and / or eighth magnetic fields) to generate a signal on a tag, the exciter assembly comprising A) a base substrate, and B) a first exciter coil mounted on the base substrate, wherein the current in the first exciter coil advances clockwise when the first, second, and third magnetic fields are generated. In some embodiments, the exciter further comprises C) a second exciter coil mounted on the base substrate, wherein the current in the second exciter coil advances clockwise when the first and second magnetic fields are generated and counterclockwise when the third magnetic field is generated. In some embodiments, the exciter assembly further comprises a third exciter coil mounted on a base substrate (D), wherein the current in the third exciter coil advances clockwise when first and third magnetic fields are generated and counterclockwise when a second magnetic field is generated. In some embodiments, the exciter assembly further comprises a fourth exciter mounted on a base substrate (E), wherein the current in the fourth exciter coil advances clockwise when first magnetic fields are generated and counterclockwise when second and third magnetic fields are generated.

[0107] Exciter coils can be wound using Litz wire to minimize resistance losses, for example, due to the skin effect that occurs as the frequency increases. The number of turns is generally selected to maximize the coil's "Q" (inductance / resistance ratio). An exemplary coil example is 63 turns of Litz wire consisting of 100 strands of 38 AWG wire. The inductance of each coil is approximately 1.1 mH, and the Q (inductive reactance to resistance ratio) is over 500 at 134.5 kHz. Other coil structures can be used with other wires having different inductance and Q values. However, generally, it is desirable to keep the "Q" as high as possible to minimize resistance losses, which result in loss of efficiency and greater thermal heating.

[0108] In some embodiments, the specification provides systems and devices comprising a) a base substrate, b) a first exciter coil mounted on the substrate and configured to generate a magnetic field for generating a signal to a tag, and c) a balun circuit electrically coupled to the first exciter coil. In some embodiments, the systems and devices further comprising a second exciter coil mounted on the substrate and configured to generate a magnetic field for generating a signal to a tag, and c) a balun circuit electrically coupled to the second exciter coil. In some embodiments, the systems and devices further comprising a third exciter coil or third and fourth exciter coils mounted on the substrate and configured to generate a magnetic field for generating a signal to a tag, and c) a balun circuit electrically coupled to the third exciter coil or the third and fourth exciter coils.

[0109] In certain embodiments, the second exciter coil, the second and third exciter coils, or each of the second, third, and fourth exciter coils is operably connected to a switch that controls the direction of current flowing through the coil. In certain embodiments, each switch comprises a repeater element, a PIN diode, a field-effect transistor, or other solid-state switching device. In certain embodiments, each switch additionally switches at least one capacitor (e.g., two capacitors) into the circuit to keep the resonant frequency of the series coupling of the exciter coils constant, regardless of the change in the total coil inductance resulting from changing the coil polarity.

[0110] The inductance of an exemplary exciter coil system is 1.1 mH for each individual coil when Q > 500. The inductance of a series-coupled coil system, such as a four-coil system (as shown in Figure 4A, for example), varies with the polarity (current direction) of the coils due to the interaction of the magnetic fluxes produced by each coil. The inductance of a series-coupled system of all four exemplary coils is 3.9 mH at Q = 435 for the current direction depicted in Figure 5, where all coils have a clockwise current. The inductance of a series-coupled system of all four exemplary coils is 4.6 mH at Q = 500 for the current direction depicted in Figure 6, where coils A and B have a clockwise current and coils C and D have a counterclockwise current. The inductance of a series-coupled system of all four exemplary coils is 4.3 mH at Q = 473 for the current direction depicted in Figure 7, where coils A and C have a clockwise current and coils B and D have a counterclockwise current. This variation in total inductance necessitates switching in an appropriate compensating capacitor when the coil polarity changes.

[0111] In some embodiments, the repeater or switch components and associated capacitors may be placed on a ceramic substrate to provide a secure mounting, excellent dielectric properties, and also function as a heat spreader to reduce localized heating of the individual components.

[0112] In some embodiments, the system and device further comprises a plurality of observation coils or observation station assemblies mounted on a substrate and configured to detect signals from tags. In some embodiments, the observation coils are positioned such that the axis of the coil lies coplanar with the central plane of the exciter coil. In this plane, the magnetic flux provided by the exciter is perpendicular to the sensing axis of the observation coil for all combinations of the coil current directions described earlier. The perpendicular exciter current does not induce a signal into the observation coil and therefore provides isolation between the exciter coil and the observation coil. This isolation is generally required to achieve the necessary system dynamic range so that very weak tag signals can be detected in the presence of a very large exciter magnetic field. This isolation is also important because crosstalk between the exciter coil and the observation coil would greatly hinder navigation without this isolation, because the crosstalk period would contribute to a significant signal originating from the same magnetic dipole (exciter) to all observation coils, and therefore the observation coils would lose their spatial impedance. An additional point is that the presence of a z-oriented exciter significantly deforms the z-component of the tag (and emitter) magnetic field, rendering it useless for navigation.

[0113] In further embodiments, the observation coils, or observation station assemblies, comprise 6 to 30 observation coils (e.g., 6...9...12...20...or 30). In additional embodiments, the observation coils are i) located on the opposite side of the base substrate, but not adjacent to the opposite side, and / or ii) each positioned in an alternating opposite orientation along the x and y axes relative to the other observation coils. This positioning minimizes crosstalk between the observation coils, thereby reducing the degree of crosstalk compensation applied (e.g., by mathematical solution software).

[0114] In some embodiments, the system and device further comprises a plurality of printed circuit boards, and each of the plurality of observation coils is operably coupled to one of the plurality of circuit boards. In certain embodiments, each circuit board comprises at least two capacitors and at least one balun circuit. In certain embodiments, the system and device further comprises coupling tags.

[0115] In certain embodiments, the system and device further comprises a balun circuit electrically coupled to each of at least one exciter coil. In further embodiments, the system and device further comprises a cable bundle electrically coupled to the balun circuit. In additional embodiments, the system and device further comprises a plurality of observation coils mounted on a substrate and configured to detect signals from coupling tags, the plurality of observation coils electrically coupled to the cable bundle.

[0116] In some embodiments, the system and device further comprises at least one self-diagnostic emitter. In other embodiments, the system and method further comprises a top cover which mates with a base substrate to enclose each of the exciter coils.

[0117] In other embodiments, the system and device further comprises a system electronics housing configured to provide signals to the exciter coils. In other embodiments, the centers of each exciter coil are separated from each other by at least 5 centimeters (e.g., 5...10...15...25...100...1000 cm). In other embodiments, the centers of each exciter coil are separated from each other by 2 to 5 times the maximum dimension of the coil itself. In certain embodiments, a fourth exciter coil is positioned next to the second exciter coil, and a third exciter coil is positioned next to the first exciter coil and diagonally opposite the second exciter coil.

[0118] In some embodiments, the Specified provides a method comprising: a) positioning the system or device disclosed herein below or near a patient in which at least two binding tags are located; and b) generating a magnetic field and thereby activating the system or device to cause each of the binding tags to generate a signal.

[0119] In some embodiments, the Specified Information provides systems and devices comprising an observation station assembly, the observation station assembly comprising: a) an observation coil comprising an observation coil having i) a metal core having a coilless proximal end, a coilless distal end, and a central region, and ii) a coil winding wound around the central region of the metal core; b) first and second observation coil brackets; and c) first and second elastomer components, wherein the coilless proximal end of the metal core is fixed between the first observation coil bracket and the first elastomer component, and the coilless distal end of the metal core is fixed between the second observation coil bracket and the second elastomer component. In certain embodiments, the system or device further comprises a remote activation device (e.g., as described herein), the remote activation device comprising at least one exciter coil. In further embodiments, the system and device further comprises an exciter assembly (e.g., as described herein), the exciter assembly comprising at least one exciter coil.

[0120] In further embodiments, the first and second observation coil brackets each include at least one adjustment component (e.g., two adjacent screws). In some embodiments, the at least one adjustment component includes at least one screw and / or at least one rod. In other embodiments, the observation station assembly further includes an electronic component electrically coupled to the observation coil. In other embodiments, the electronic component includes at least one capacitor and / or at least one balun circuit. In further embodiments, the electronic component includes a printed circuit board.

[0121] In certain embodiments, the observation station assembly further comprises a Faraday shield. In other embodiments, the observation station assembly further comprises i) electronic components electrically coupled to the observation coil, and ii) a Faraday shield. In additional embodiments, the first and second elastomer components comprise materials selected from elastomer polymers and springs.

[0122] In some embodiments, the metal core includes a ferrite core. In other embodiments, the metal core has a diameter of 4 to 25 mm (4, 8, 12, 14, 16, 25 mm). In certain embodiments, the metal core has a length of 15 to 75 mm (e.g., 15, 30, 45, 58, 75 mm). In certain embodiments, the coil winding includes a metal wire. In other embodiments, the metal wire is wound 150 to 300 times around the metal core. In further embodiments, the first and second observation coil brackets each include notches configured to fit the wireless proximal end and / or wireless distal end of the metal core.

[0123] In certain embodiments, the Specified Provisions provide a device and system comprising: a) a mounting component (e.g., a sheath) configured to be attached to a handheld medical device having a device tip, the mounting component comprising: i) a proximal end; ii) an angled distal end having a distal end opening configured to allow the device tip to pass through but not the rest of the medical device; and iii) a body extending between the proximal end and the angled distal end; and b) first and second place emitters attached to the mounting component.

[0124] In certain embodiments, the angled distal end has an angle of at least 35 degrees (e.g., at least 35...45...65...85... or 95 degrees) with respect to the longitudinal axis of the mounting component. In some embodiments, the angled distal end has an angle of about 90 degrees with respect to the longitudinal axis of the mounting component. In further embodiments, the first and second place emitters are mounted (e.g., spaced apart) on the body of the mounting component.

[0125] In other embodiments, the system and device further comprises c) a display component housing, which is mounted on or can be mounted on the proximal end of a mounting component. In additional embodiments, the system and device further comprises a display component mounted on the display component housing, which comprises a display screen (e.g., an LCD screen) for displaying the location of an implanted tag in a patient relative to the device tip on a medical device. In other embodiments, the display component housing comprises a cable management component. In additional embodiments, the display component housing comprises a housing tapered connector. In further embodiments, the proximal end of the mounting component comprises a proximal tapered connector.

[0126] In other embodiments, the device and system further comprises first and second place emitter wire leads, the first place emitter wire lead being electrically coupled to a first place emitter (e.g., a small coil), and the second place emitter wire lead being electrically coupled to a second place emitter (e.g., a small coil). In other embodiments, the system and device further comprises an adhesive strip sized and shaped to cover at least 50% (e.g., 50%...75%...90%) of the mounting component body and configured to adhere the mounting component to a medical device. In certain embodiments, the system and device further comprises a medical device. In other embodiments, the medical device includes an electrocautery surgical device.

[0127] A. Addressing the variable alignment between the external coil (e.g., tag coil) and the exciter assembly. In some embodiments, the exciter is configured to provide power to the tag independently of the alignment of the tag's coils with the exciter. For example, in some embodiments, power transfer to the tag may depend on the relative orientation of the exciter magnetic field with respect to the tag. In some such embodiments, unless corrective measures are taken, the tag may only be able to collect power from the portion of the electric field aligned with the tag's coils (e.g., the ferrite core coils contained within the tag). This problem may be solved by including multiple exciters that can provide all three orthogonal directions of the magnetic field. However, this leads to a thicker assembly and prevents both the rejection of coupling between the primary exciter coil (e.g., located within the exciter assembly) and the sensing coil (also located within the exciter assembly) (see Section B below), and the rejection of secondary electric field coupling between the tag / emitter and the exciter coil (see Section C below), which subsequently couples with the sensing coil and impairs the positioning of the tag or emitter. To address this challenge, the Specified Provisions provide an exciter assembly configuration that provides a mechanism for changing the orientation of the magnetic field by an exciter coil that can be deployed in only one magnetic direction.

[0128] In some embodiments, this is achieved by having multiple coils within the exciter assembly (see, for example, Figure 4A) and setting the direction of the current in each coil to either clockwise or counterclockwise (see, for example, Figures 5-7). In some embodiments, the coils are connected in series such that the same current flows through each. In some embodiments, the coil layout comprises four coils in two rows centered at (X1,Y1), (X1,Y2), (X2,Y1), and (X2,Y2) coordinates, with three sets of current configurations: Configuration 1: all currents clockwise to simulate an exciter coil aligned with a plane perpendicular to the Z axis; Configuration 2: coils centered at (X2,Y1) and (X2,Y2) with currents flowing counterclockwise to simulate an exciter coil aligned with the X axis; and Configuration 3: coils centered at (X1,Y2) and (X2,Y2) with currents flowing counterclockwise to simulate an exciter coil aligned with the Y axis. Any number of other coil configurations may be used. For efficiency, it is desirable (though not required) to minimize the number of components and the overall complexity of the design. However, in some embodiments, it may be desirable to have five or more coils (e.g., 6, 8, 10, 16, etc.) within the exciter assembly to provide greater flexibility for changing the electric field direction, even at the expense of system complexity.

[0129] For each configuration, tuning the coils within the exciter assembly requires little variation between configurations when the same current flows through all coils in all configurations. This is because the influence of one exciter coil on others depends on the state of the first exciter coil (open circuit, current carrier, etc.).

[0130] To provide optimal performance, the area of ​​the exciter coil should be maximized, and the distance between the centers of the coils should be minimized. Larger area coils provide a higher electric field for the same applied current. Coils separated by a greater distance result in greater directional changes for configurations 2 and 3.

[0131] Figure 3 provides an exemplary schematic of a four-coil exciter assembly in several embodiments of the present invention, where the four coils are labeled coil A, coil B, coil C, and coil D (see Figure 4A).

[0132] In medical applications where the exciter assembly is provided on a flat, planar surface directly beneath the patient (e.g., a pad), a clinically preferred system geometry involves all four coils being placed very close to each other. As a result, the magnetic coupling between each coil varies depending on the individual coil polarity, and therefore the total inductance of all four coils in series varies depending on the combination of coil polarities. Thus, optimal performance inevitably involves balancing conflicting factors. To compensate for this, in some embodiments, a switching system is employed in which additional series capacitive reactance is inserted when the total inductance is increased, so that the tuning center frequency is maintained at the desired excitation frequency. In a preferred embodiment shown in Figure 3, repeaters are used for switching. Other embodiments may employ solid-state switching techniques such as PIN diodes. Any preferred mechanism to achieve switching may be used.

[0133] In some embodiments, the centers of the coils are separated by 10...50...100...500... or 1000 cm. In some embodiments, each coil has an area of ​​25...625...2500...62,500... or 250,000 cm². 2Therefore, the maximum total series capacitance is required when all four coils have the same polarity. In some embodiments, this series capacitance is equally distributed among all four coils and balanced on both sides of a switching repeater as shown in Figure 3. Distributing the capacitance in this way keeps the contact voltage present in the switch to a minimum. Otherwise, the high "Q" of the coils could result in excessively high voltages present in the switch and interconnects, exceeding 10kV in some configurations.

[0134] Additional capacitance useful for maintaining the desired resonant frequency as described above (e.g., adding a capacitor in series to reduce capacitance) is switched by polarity switching repeaters or separate switches that can be energized when needed. In some embodiments, this capacitance is distributed between polarity switching repeaters for both minimizing terminal voltages and minimizing common-mode coupling by achieving best symmetry.

[0135] In some embodiments, each capacitive element consists of multiple capacitors to minimize the voltage across each capacitor to ensure that it does not exceed the voltage capability of the capacitors, and to minimize heating due to losses that could otherwise cause the resonant frequency to drift.

[0136] In some embodiments, the balun is incorporated as close as possible to the exciter coil (see Section D and Figure 3 below). The baluns described below achieve common-mode rejection to reduce or eliminate electric field generation and also provide impedance matching to optimally match the coil assembly impedance with that of the transmission line and power amplifier. In some embodiments, the primary (amplifier side) of the balun has eight turns and the secondary (coil side) has four turns, thus resulting in a well-matched impedance change from 4 to 1, for example, from a 50-ohm generator output impedance to a 12-ohm coil impedance at resonance. Other turns ratios may be used for optimal impedance matching to other characteristic impedances of the transmission line and amplifier.

[0137] Figure 3 provides an exemplary embodiment of a coil system used in an exciter assembly. In this figure, several capacitors are identified by numbers (e.g., C1, C5, C11, C40, etc.; pF (picofarads)) and their relative positions to coils A, B, C, and D (see, for example, Figure 4A). A balun with a 7:4 turns ratio is shown (the balun transform ratio is matched to an impedance to 50 ohms using a 7:4 ratio with seven turns on the 50-ohm side and four turns on the coil side). The system can be configured or tuned to optimize performance based on the mode in which the coils are used, for example, as shown in the exemplary embodiment of Figure 3: Electric field: Z-plane (++++) Capacitors C9 and C10 are 25,600pF (20,000pF in parallel with 5,600pF); Electric field: X-plane (+-+-) Capacitors C19 and C20 are 27,235pF ((2) 27,000pF is used in series connection of 470pF capacitors and in parallel); Electric field: Y plane (++--) Capacitors C29 and C30 are 6,050pF ((2) 3,300pF in parallel with a series connection of 100pF capacitors, and 2,700pF in parallel with 100pF capacitors); Common (all electric fields): Capacitors C39 and C40 are 9,000pF ((3) 3,000pF capacitors connected in parallel); Capacitors C39 and C40 (values ​​XY - fixed) are 9,000pF (18,000pF in series with 18,000pF; 9,220pF; 8,200pF in parallel with 820pF, or other combinations; total voltage is 660Vrm).

[0138] Other specific values ​​of capacitance can be used to provide one or more desired resonant frequencies with different inductance values ​​that may result from different coil structures.

[0139] B. Address the exciter electric field strength near the sensor. The exciter electric field strength used to power the tags is generally close to the exciter to create a large voltage that can power one or more tags. This electric field is much larger than the electric field provided by the emitter associated with one or more tags or surgical instruments (tags and emitters are referred to herein collectively and individually as “beacons”). Also, since a single excitation assembly device is preferred to provide both excitation and sensing, the sensing components must be very close to the exciter components. Thus, the magnetic field sensor typically senses the magnetic field at an exciter frequency that is very large, approximately 160 dB, or greater than the desired signal (from the beacon).

[0140] This problem can be partially solved using electronic filters. However, the rejection capabilities of these filters are limited, they are expensive, and they are physically large. Filters can be active or passive. However, since active electronic filters have an inherent noise floor that limits the dynamic range and filtering effectiveness in this very high dynamic range situation, passive filters may be used in some embodiments.

[0141] An alternative (or additional) solution is to utilize the coil system described in Section A above. In such embodiments, the exciter electric field pickup by the sensor can be reduced by utilizing the vector nature of the magnetic field. In some embodiments, an exciter coil is selected that has an orientation that generates only magnetic flux substantially perpendicular to the XY plane containing the sensing coil. In some embodiments, a ferrite core coil, which is similarly highly directional, is then aligned to its plane, and as a result, magnetic flux perpendicular to the plane is not sensed. This results in the rejection of the exciter electric field by more than 40 dB. In preferred geometry, isolation of more than 70 dB is achieved for all sensing coils in all three polarity configurations described above. Both the height and inclination of each observation coil are adjusted to achieve the alignment required to achieve this level of isolation for all three coil polarity states. Isolation is typically measured using a vector network analyzer by connecting the exciter coil to port 1 and a particular observation coil to port 2. 21 The magnitude and phase are then measured at the receiving frequency. In a preferred embodiment, the selected receiving frequency is 130.2 kHz.

[0142] In such embodiments, the system therefore uses one magnetic field direction for excitation and the two remaining directions (perpendicular to the excitation direction) for sensing. In other embodiments, two orthogonals can be used for excitation and one orthogonal for sensing. However, it may be preferable to use two orthogonals for sensing in order to provide faster prediction of the beacon position.

[0143] Addressing C. exciter / beacon coupling. In some embodiments, the exciter is a highly resonant coil. In some embodiments, because the beacon's frequency is close to the exciter's resonant frequency, a portion of the beacon's AC magnetic field aligned to the exciter coil orientation may induce a current within the exciter, thus producing a magnetic field at the beacon frequency in the exciter coil orientation. This effect deforms the original electric field from the beacon, making it more difficult to locate the beacon. In clinically preferred geometry, this deformation may mask the beacon's true location, potentially making navigation difficult or impossible.

[0144] This coupling can be reduced by selecting different beacon frequencies that are not too close to the exciter resonance. However, in some preferred embodiments, the available bandwidth is limited because the beacon utilizes a single ferrite core RF coil for both reception and transmission.

[0145] Instead, using the exciter configuration described in sections A and B above, the sensing system consisting of sensing coils is oriented perpendicular to the exciter coils, so the deformed electric field is not sensed. In other words, the deformation is limited to the magnetic field direction substantially aligned with the exciter coils, which are perpendicular to the sensing system. Thus, the true location of the beacon is no longer masked by the electric field deformation caused by the exciter current at the beacon frequency, and accurate navigation is achieved without artifacts.

[0146] D. Dealing with the magnitude of the electric field produced by the system. The exciter and associated circuits should be designed to minimize the magnitude of the electric field produced by the system. If an electric field is produced, it can capacitively couple into the sensing system, reducing system accuracy. Electric fields also interact with the patient and the environment far more significantly than magnetic fields.

[0147] In some embodiments, this problem is solved by incorporating the balun as close to the exciter coil as possible. The balun, which can also act as an impedance transducer, minimizes the electric field by eliminating asymmetric currents with respect to ground. Another possible approach is for the balun to eliminate common-mode coupling. In some embodiments, on the exciter side of the balun, the circuit design and layout must be as symmetric as possible to maintain balance.

[0148] In addition to reducing electric field effects, the converter allows commercially available 50-ohm coaxial transmission lines to be used without mismatch. This scales the transmission line voltage and current to optimally transmit power to the exciter assembly via the most efficient, smallest, and most flexible coaxial cable.

[0149] E. Identifying and managing the locations of multiple beacons. According to the method described herein, two or more beacons (e.g., tags, emitters associated with one or more surgical devices, or other objects for which location, position, relative position, or other spatial information is desired) are used. The two or more beacons (e.g., tags) are coupled to one another by a linker (e.g., a "coupled tag"). In some embodiments, each beacon generates the same frequency. Such embodiments may be advantageous because the signal strength can be up to twice as large as that of a single beacon (assuming two tags are used, three times as large if three tags are used, four times as large if four tags are used, etc.). Thus, such embodiments may be useful in larger patients, where the patient's tissue volume otherwise limits the ability to detect a signal from a single beacon.

[0150] In some embodiments, each beacon generates the same frequency, and the two signals can be deconvolved to improve overall accuracy in detection. In some embodiments, the tags are programmed to respond at an offset frequency compared to the frequency of the stimulus frequency. In some embodiments, the tags are programmed to respond at the offset frequency and a stable phase locked to the phase of the stimulus signal. This strategy allows the response signal to be easily decoupled from the stimulus signal. In particular, the stable phase locked to the stimulus signal allows for precise localization of the signal of each of at least two coupled tags. In some embodiments, each of two or more tags is programmed to generate the same frequency but have a set phase offset. In some embodiments, each beacon generates the same frequency, but the phase of each beacon may be a random factor of 11.25 degrees, which can be utilized to deconvolve the two signals.

[0151] In some embodiments, each different beacon (e.g., tag) generates a unique frequency, frequency spectrum, or other distinguishable signal. In some such embodiments, a search algorithm is used to identify one or more spatial pieces of information from the beacons. In some embodiments, the optimal exciter polarity and power level are identified for each beacon (e.g., considering any relative orientation of the beacon to the exciter) by circulating the exciter through different planes. Based on this information, the optimal exciter pattern is calculated to maximize the quality of the procedure and the accuracy of the information conveyed to the user (e.g., the treating physician). In some such embodiments, the first optimal pattern is used to provide spatial information for a first tag, and the first part of the procedure is performed. Then, the second optimal pattern (which may be the same or different) is used to provide spatial information for a second tag, and the second part of the procedure is performed. Further circulation may be performed for additional tags. Alternatively, the exciter pattern (polarity and power) may circulate between multiple different optimal patterns during the procedure to provide near real-time optimal spatial information for multiple beacons. In some such embodiments, rapid switching of the coil polarity within the emitter is used to power two or more beacons simultaneously or nearly simultaneously.

[0152] F. Exemplary Protocol This technology is not limited by the mode of tag placement and envisions a variety of placement techniques, including but not limited to invasive surgery, laparoscopy, endoscopy, and intravascular catheterization. The tags may be placed by any suitable device, including but not limited to syringes, endoscopes, bronchoscopes, wide-band bronchoscopes, laparoscopes, and thoracoscopes. An exemplary protocol is provided below.

[0153] Patients previously identified with a breast tumor are admitted to a medical facility. The patient is initially sent to the radiology department. The radiologist examines previous imaging data to identify the target tumor. The subject is administered a local anesthetic, usually lidocaine or a derivative, using a percutaneously introduced needle. The subject is positioned using an imaging device, typically ultrasound, conventional mammography, or a stereotactic device. The location of the tumor is determined. A guide needle (usually 6-20 gauge) is inserted either within or immediately adjacent to the tumor, and a biopsy needle is placed through the guide needle. The sample is obtained using various methods (aspiration, mechanical cutting, or mechanical cutting after freezing to fix the tissue position). After the sample is obtained and sent for pathological examination, a 6-20 gauge tag delivery needle is inserted into the tissue via a coaxial guide needle, with its distal open end positioned in the lesion. Two binding tags are inserted into the proximal end of the delivery needle and delivered into the tissue by a plunger through an opening at the distal end of the needle. Alternatively, the tags may be pre-positioned at the distal end of the delivery needle. The correct location of the binding tags is confirmed by imaging. The delivery needle is then withdrawn, leaving the tags in place within the breast tissue.

[0154] This type of procedure can be performed in a similar manner in virtually any body space, organ, or pathological tissue for the purpose of locating that tissue or space for further diagnosis or any kind of treatment. Areas of specific interest include, but are not limited to, the following organs and disease processes occurring within them: the brain, skull, head and neck, thoracic cavity, lungs, heart, blood vessels, gastrointestinal structures, liver, spleen, pancreas, kidneys, retroperitoneum, lymph nodes, pelvis, bladder, genitourinary system, uterus, ovaries, and nerves.

[0155] In some embodiments, during surgery, the patient is placed on an operating table with the surgical area exposed and sterilized. The surgeon is provided with imaging information indicating the location of the target tissue (e.g., tumor) and the tag. An incision is made at the site of insertion of the placement needle. A remote activation device is placed close to the tissue to activate the tag. A detection component with an observation station (e.g., as shown in Figure 4A) detects a signal from the tag, allowing the surgeon to direct the medical device toward the tumor. Once the tumor is located, the surgeon removes the appropriate tissue and, optionally, the tag.

[0156] In some embodiments, the system satisfies use in surgery where tags are placed on or within the body as reference points. The relative positions of the tags and any surgical instruments are determined using an electromagnetic field. This information is communicated to the physician in real time using a variety of methods, including but not limited to visual methods (computer screens, direction and depth indicators using various methods, tactile feedback, audio feedback, holograms, etc.), and the instrument positions are displayed on any medical image, such as a CT, MRI, or PET scan in 2D or 3D. This data satisfies use to guide the physician during a procedure or is used as a training method so that the physician can perform a virtual procedure. Such systems may be integrated into existing surgical systems, such as the STEALTH system (Medtronic) for applications such as neurosurgery, or may provide an alternative method thereto.

[0157] In some embodiments, information regarding the location of a tag or the surgical path or route to the tag is communicated to the surgeon or other user in a manner that includes one or more augmented reality or virtual reality components. For example, in some embodiments, the surgeon wears or accesses a virtual reality device (e.g., goggles, glasses, helmet, etc.) that displays a partial or complete virtual image of the patient or surgical field. Tag location information collected and calculated by the system described herein is presented to the surgeon by one or more visual components to assist in the precise targeting of one or more tags. For example, tissue containing a bound tag may be represented by a virtual image of the indicated tag location. Similarly, in some embodiments, the surgical path is presented visually, for example, as a colored line to be followed. In some embodiments using augmented reality features, the display overlays one or more augmented features onto the display, presenting a patient figure or image capture representing what the surgeon would visualize if a monitor were not present. The figure or image display data may be captured by one or more cameras in the surgical field. The extended feature section includes, but is not limited to, a representation of the tag's location within the target tissue, a projected surgical path, a target point for the surgeon to align the tip of the surgical device, a simulated surgical margin area to be treated, arrows or other location indicators that suggest movement in case of deviation from the optimal path, or similar.

[0158] Exemplary exciter assemblies 250 are shown in Figures 4, 5, 6, and 7. These exciter assemblies may be positioned beneath a patient's mattress while the patient lies on a surface such as an operating table or mattress, as shown in Figure 1. The exemplary exciter assemblies in these figures provide excitation signals for tags within the patient via four exciter coils 150. The exemplary exciter assembly in Figure 4A provides multiple observation coil assemblies (also known as observation station assemblies) 161, each having an observation coil 160, for detecting signals from implanted tags and tags within attachment components mounted on surgical devices. The exciter assembly consists of a base substrate 140 on which other components are typically mounted or integrated. The base substrate is made of any suitable material, which may be, for example, polycarbonate or similar, and is typically non-magnetic and non-conductive. Not depicted in Figure 4A is a top cover 230 (see Figure 8) that mates with the base substrate and encloses all internal components. The top cover consists of any suitable material, including Kevlar® and / or other rigid materials, which are typically nonmagnetic and nonconductive. Foam or other types of filler may be included on top of the top cover.

[0159] Mounted on the base board are four large exciter coils 150, which are referred to as “Coil A,” “Coil B,” “Coil C,” and “Coil D” in Figure 4A. Each exciter coil 150 may be wound around four exciter coil mounts 155. In certain embodiments, the exciter coils are not wound in any particular form, but instead use wires that adhere to themselves to create the coil shape. Although not shown in Figure 4A, in certain embodiments, a coil cover (e.g., a plastic coil cover) is located above each of the four exciter coils. A large central balun circuit 180 is located between the four exciter coils, which are generally positioned in the center.

[0160] Inside the exciter coils B, C, and D is a switch 190. The switch 190 includes components such as repeaters or multiple PIN diodes (e.g., at least four PIN diodes) or a field-effect transistor that control the direction of the current (clockwise or counterclockwise) in each exciter coil. In a particular embodiment in Figure 4A, the excitation coil A does not have a switch 190 because the direction within this coil is not changed. The switch 190 is coupled to different capacitors used to properly match the different inductances resulting from changing the direction of the current. When repeaters (e.g., four SPSTs, two SPDTs, or one DPDT) are used within the switch, they generally direct the input to one of two outputs. When multiple PIN diodes are used within the switch 190 (to create a repeater function), they provide a very high impedance when "off" and a low impedance when "on". Each switch 190 is also coupled to one or more capacitors to correct the capacitance that forms a resonant circuit together with the exciter coil inductor. This is necessary because when the direction of the current changes, the effective total series inductance of all the exciter coils changes. Further inside coils A-D is a pair of capacitor assemblies 195, each consisting of a central capacitor 197 flanked by metal leads 199. In certain embodiments, the metal leads 199 are attached to a ceramic thermal spreader to dissipate heat accumulated during operation.

[0161] During operation, the exciter assembly in Figure 4A is configured, in certain embodiments, to circulate between three configurations called Configuration 1 (shown in Figure 5), Configuration 2 (shown in Figure 6), and Configuration 3 (shown in Figure 7). In Configuration 1, as shown in Figure 5, the current from all four exciter coils is clockwise to simulate exciter coils that are generally aligned with their plane perpendicular to the Z-axis. In Configuration 2, as shown in Figure 6, the current from coils A and B is clockwise, while the current from coils C and D is counterclockwise, to simulate exciter coils that are generally aligned with the Y-axis. In Configuration 3, as shown in Figure 7, the current from coils A and C is clockwise, while the current from coils B and D is counterclockwise, to simulate exciter coils that are generally aligned with the X-axis. While this is a preferred embodiment, other combinations of coil polarities with additional series capacitance of other values ​​may be advantageous for specific tag orientations. For example, the current in coil A may be counterclockwise instead of clockwise, in which case all three other coils (coils B, C, and D) may have currents as shown in Figures 5, 6, or 7, or the other three coils (coils B, C, and D) may have opposite currents as shown in Figures 5, 6, and 7. In another embodiment, the current arrangement is as shown in Figure 6, except that the current in coil B is counterclockwise and the current in coil D is clockwise. All different combinations of clockwise and counterclockwise currents of coils A-D are considered (i.e., all 16 combinations).

[0162] The exemplary exciter assembly 250 in Figure 4A is also shown with 12 observation station assemblies 161 (each having an observation coil 160). The 12 observation coils 160 alternately oriented in opposite directions (along the x and y axes) to reduce crosstalk. In other embodiments, software is used to reduce crosstalk, similarly or alternatively. In certain embodiments, all observation coils face towards the center rather than alternatingly oriented, which increases crosstalk but may have the advantage of shifting the location of the inflection point in the observation coil signal pickup as the beacon is migrated across the outer perimeter of the exciter assembly. Generally preferred, to avoid reduction in isolation and noise pickup, wires feeding into the exciter coils are not extremely close to any of the observation coils. In Figure 4A, the wires from the central balun circuit to each of the four exciter coils are located away from the 12 observation coils 160. Furthermore, as shown in Figure 4A, the observation coil extends downwards on the left and right sides of the exciter assembly and does not extend over the top or bottom of the exciter assembly. Adding observation stations over the top and / or bottom can introduce significant crosstalk. Alternatively, software applications may be used to reduce crosstalk if the observation coil is positioned in a way that induces crosstalk. The observation coil 160 is held in place by a pair of observation coil brackets 165.

[0163] Next to each observation coil 160 is a printed circuit board 170. Each printed circuit board 170 contains a capacitor and a small balun circuit. The capacitor, together with the observation coil, is used to create a resonant circuit. The balun serves to eliminate the common-mode effect, which, without the balun, would make the observation coil assembly sensitive to electric field interactions. It can also serve as an impedance matching element, matching the real impedance of the coil / capacitor resonant circuit to the transmission line characteristic impedance, typically 50 ohms, by optimally selecting the number of primary and secondary turns.

[0164] The exciter assembly 250 in Figure 4A is also shown with a pair of self-diagnostic emitters 220. These self-diagnostic emitters 220 are present so that a known signal can be applied and the response to all observation coils can be checked. If the observation coils do not show the expected signal, it may indicate a system problem or the presence of an interfering magnet or metal piece that is deforming the electric field and reducing the overall positioning accuracy. It should be noted that another self-diagnosis that may be used is to generate a signal on the exciter coil that is normally applied to one of the emitters on a mounting component (e.g., a sheath on a handheld surgical device). By measuring the signal passed from the exciter to each observation coil, the level of separation between them can be determined. Still another self-diagnosis, the signal may be applied to each observation coil individually, and the remaining observation coils may be used to detect the signal. In other embodiments, electric field observation coil crosstalk may also be measured in this manner and used to calibrate the system.

[0165] Figure 4A shows the various wire connections between the various components of the exciter assembly. Each observation coil 160 is mounted on a coaxial cable connected to a system electronics housing (labeled "controller" 210) via a cable bundle 200. The exciter signal originates from the cable bundle 200 into a central balun circuit 180. From there, wires transmit the signal to the switch 190 and / or capacitor assembly 195. The system electronics housing (controller 210) performs signal processing on the observation coil signals (e.g., filtering, mixing, amplification, digitization, and demodulation of multiple frequency "channels"). Generally, the A / C mains power is not applied to the observation coils.

[0166] With respect to the capacitors used within each capacitor assembly 195 and on the printed circuit board 170, the capacitors are generally selected to be of the COG / NPO type, whose capacitance value does not change with temperature, so that the resonant frequency of the exciter does not change with temperature. The capacitors also provide a tuning network to which capacitance can be selectively added in series to change the resonant frequency, which helps reduce tolerances during manufacturing and provides greater resistance to tuning changes due to temperature and other factors. In general, all materials used should have high dielectric strength and high stability with respect to temperature in order to prevent geometric changes when the exciter assembly is used and the temperature rises.

[0167] An exemplary observation coil assembly (also known as an observation station assembly) 161 is shown in Figure 4B. The observation coil assembly 161 includes two observation coil brackets 165 used to fasten a robust observation coil 160 to an elastomer 162. The observation coil 160 consists of a metal core (e.g., a ferrite core) 166 and a coil 167 formed from wire, as shown in Figures 4B and 4C. As shown in exemplary Figure 4C, the metal core 166 consists of a central region 173 (below the wire in Figure 4C) with a wireless proximal end 171 and a wireless distal end 172. Only the ferrite core (using the wireless proximal and distal ends) is fastened by the bracket 165 and elastomer 162 (e.g., to provide best registration and eliminate the possibility of damaging the coil winding 167 of the observation coil 160). The height of each end of the observation coil 160 can be adjusted up or down by adjustment screws 163 (located within each observation coil bracket 165), while a restoring force is provided by an elastomer 162. The elastomer thickness and hardness tester is selected to provide the necessary restoring force for a desired range of adjustment, so that the adjustment screws are easily adjusted, while still holding the desired setting once the optimal position is achieved. In addition, each coil bracket 165 has a "V" or "U" shaped feature that allows them to fix the proximal and distal ends of the metal core 166. This is because, for example, the bracket 165 cannot rotate around an axis perpendicular to the plane containing the exciter coil, so that it can strictly register the observation coil core (e.g., a ferrite core) in a desired direction. The observation coil assembly 161 also includes a printed circuit board 170 (having a capacitor and balun circuit) and a Faraday shield 168. The Faraday shield may consist of a conductive material such as brass or copper.

[0168] In certain embodiments, an exciter coil (e.g., as shown in Figure 4A) is connected to port 1 of a vector network analyzer, i.e., a VNA. The observation coil output is typically connected to port 2 of the VNA, and the transmission (S21) is measured and displayed. This measurement is a direct measurement of the signal present in port 2 resulting from the excitation provided to port 1, and therefore a direct measurement of separation. A lower (more negative) S21 is better. A typical separation value (S21) achieved by generally preferred embodiments is -70 dB, with a usable range including -50 dB to over -100 dB (e.g., the noise floor of the VNA).

[0169] In general, to achieve the best isolation between the exciter coil and the observation coil for the best accuracy over the maximum navigation amount, it is generally important to position the observation coil perpendicular (e.g., exactly perpendicular) to the magnetic flux provided by the exciter coil. Figure 4A shows such a perpendicular arrangement of 12 observation coils. Even a small offset in the height or inclination of the observation coil from this optimal position will generally result in signal coupling from the exciter coil to the observation coil, which subtly impairs the isolation. Therefore, in certain embodiments, screws (or other connectors) on the observation coil bracket are used to make fine adjustments.

[0170] Figure 4C shows an exemplary observation coil 160, including how coil 167 is formed by wire wound around a metal magnet core in three stages: i) winding direction 1, where the wire is wound around the majority of the first half of the metal magnet core; ii) winding direction 2, where the wire is wound over the wire wound on the first half and over the majority of the second half of the metal magnet core; and iii) winding direction 3, where the wire is wound back over the second half of the wire. In certain embodiments, there are 80 to 140 windings (e.g., 80...90...112...140) in each half of the metal magnet core (e.g., 160 to 280 windings in total (e.g., 160...200...224...280)). In certain embodiments, the wire is 32AWG copper magnet wire (e.g., 0.02794 cm (0.011 inch) in diameter) with a single layer polyester enamel and adhesive coat, and heat is used during wrapping to fix the wire wrap. In certain embodiments, the metal magnet core is FAIR-RITE Products The ferrite core part number is 4077484611 from the Corporation. In certain embodiments, the metal core (e.g., ferrite core) has a diameter of about 10-15 mm (e.g., 10...12...14...15 mm) and a length of about 30-50 mm (e.g., 30...35...45...50 mm). In certain embodiments, the metal core has a diameter of about 12.7 mm and a length of about 41.5 mm.

[0171] The wires are also connected to the secondary of a small balun transducer (part 170 in Figure 4B, in a printed circuit board) through one or two series capacitances (e.g., in a printed circuit board) for each wire from the coil. Generally, in certain embodiments, the total series capacitance is selected to resonate with the inductance of the coil in the tag, and the turns ratio of the balun transducer may be selected to match the actual impedance of the resonant coil / capacitor circuit to the transmission line (e.g., about 50 ohms). In certain embodiments, the actual impedance of the resonant coil / capacitor circuit is typically 10 to 25 ohms, but can vary from just a few ohms to over 50 ohms and can be appropriately matched by the appropriate selection of the primary and secondary turns of the balun transducer. In addition to its role as an impedance transducer, the balun can be considered to minimize any electric field generation / suposcopy from the observation coil assembly, and alternately, it can be considered to eliminate common-mode effects. To further reduce electric field susceptibility, the use of a conductive Faraday shield 168 covering the balun and capacitor is employed. This Faraday shield (e.g., a Faraday cage) reduces the observed electric field to the components beneath the shield. Typically, a Faraday shield is used to reduce the emission of electric fields to components beneath the shield, in which case it also reduces the reception of electric fields.

[0172] Figure 8 shows the emitter component 250 with the top cover 230 attached. The top cover 230 may be made of Kevlar® or other preferably tough material. The exciter assembly 250 is shown with the cable bundle 200 pulled inside.

[0173] Figure 9 shows the mounting component 10, which has an angled distal end 300 into which the distal end 25 of the medical device 20 is inserted. The display component 40 is mounted to the mounting component control device 310 via the mounting component wire 60.

[0174] Figure 10A shows the distal end 25 of the medical device 20 after it has been initially inserted into the angled distal end 300 of the mounting component 10. This figure shows the mounting component wire 60 before it is inserted into the cable management component 315. Figure 10B shows the mounting component wire 60 before it is mounted into the cable management component 315 of the display component housing 330. Figure 10B also shows the housing tapered connector 340 into which the proximal end tapered connector 350 of the mounting component 10 is inserted. The cable management component 315 has two clips that align both the mounting component wire 60 and the medical device wire 50.

[0175] Figure 11 shows a mounting component 10 that is mounted in a display component housing 330. The mounting component 10 has a pair of place emitters 70 that are coupled to a place emitter wire lead 72 located inside a tube 360. The place emitters 70 are powered by the wire lead 72 to generate a signal that is detected by an observation coil. The mounting component also has an angled distal end 300 with a distal end opening 305 that allows the tip of a medical device or other device to pass through and be inserted. The display component housing 330 has a cable management component 315 consisting of a pair of clips for holding the mounting component wires and medical device wires.

[0176] Figure 12 shows an exemplary mounting component 10 fitted into a display component housing 330 with the display component 40 positioned inside. A display cover 370 used to secure the display component 40 to the inside of the display component housing 330 is shown. Also shown is an adhesive strip 380 (e.g., a double-sided strip with strong adhesive on both sides) that fits inside the mounting component and is shaped and sized to help secure the medical device to the mounting component.

[0177] Figure 13A shows the proximal end tapered connector 350 of a mounting component 10, which is configured to press and fit into the housing tapered connector 340 of the display component housing 330. Figure 13B shows a magnified view of area A in Figure 13A, which is part of the cable management component 315 and includes a cable management tapered connector 317 designed to be inserted into the tapered connector hole 319 of the display component housing 330. The cable management tapered connector 317 includes a flat portion 318 for locking the angular position.

[0178] Figure 14 shows an exemplary system for locating a tag implanted in a patient. The system consists of an exciter assembly that emits a signal to activate the tag within the patient. The system electronics housing is shown as a movable cart that delivers signals to the exciter assembly and receives and processes signals from the tag within the patient and location emitters within the implantable components. Guidance for the surgeon is displayed on a display component, as well as on a screen on the system electronics housing.

Claims

1. a) at least two tags; b) a linker attached to said at least two tags; c) a remote activation device that generates a magnetic field in the region of each tag; d) a plurality of sensors configured to detect signals from each tag while each tag is exposed to said magnetic field; Equipped with the linker is configured to hold the at least two tags in a first relative positional relationship when the linker is present in the insertion device, and to hold the at least two tags in a second relative positional relationship when the linker is removed from the insertion device; system.

2. 10. The system of claim 1, further comprising a wire or line, the wire or line passing through the linker at two or more points on the linker.

3. The system of claim 1 , wherein the linker comprises a torsion spring.

4. 10. The system of claim 1, wherein each of the tags is attached to the linker via heat shrink tubing.

5. 2. The system of claim 1, wherein at least one of the tags in the second relative positional relationship is generally oriented in a first axial direction and at least one of the tags is generally oriented in a second axial direction different from the first axial direction.

6. The system of claim 1 , wherein the at least two tags include a first tag, a second tag, and a third tag.

7. 7. A system according to any one of claims 1 to 6, i) the linker is a flexible linker; ii) the linker comprises a plastic; A system that satisfies one or more of the following criteria.

8. 8. The system according to claim 1, wherein the linker is made of a shape memory alloy.

9. 6. The system of claim 5, wherein the at least two tags are positioned such that the first axis and the second axis form an angle in the range of 15 degrees to 40 degrees.

10. 8. A system according to any one of claims 1 to 7, The system wherein the linker includes a grip that is graspable by a surgical instrument.

11. The system of claim 10, wherein the grip is a sphere.

12. 11. The system of claim 10, wherein the linker is positioned within a package, the package having a notch formed therein that exposes the grip.

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