Radio frequency receive coil network for single-sided magnetic resonance imaging.

Abstract

A single-sided magnetic imaging device is disclosed that includes a permanent magnet, where a Z-axis is defined in the field of view through the permanent magnet. The single-sided magnetic imaging device further includes an electromagnet, a gradient coil set, a radio frequency transmission coil, a radio frequency receiving coil, and a power source. The power source is configured to generate an electromagnetic field in the field of view along the Z-axis. The electromagnetic field includes a field gradient in the field of view, and adjustment of the radio frequency transmission coil is configured to target locations within the field gradient in the field of view.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims priority to U.S. Provisional Patent Application No. 62 / 979,332, filed on February 20, 2020, entitled "SYSTEM AND METHOD FOR UTILIZING RADIO FREQUENCY RECEIVE NETWORK FOR SINGLE - SIDED MAGNETIC RESONANCE IMAGING" under 35 U.S.C. § 119(e), the entire disclosure of which is incorporated herein by reference.

Background Art

[0002] Magnetic Resonance Imaging (MRI) systems have primarily focused on the impact on enclosed form factors. This form factor includes surrounding the imaging region with electromagnetic field - generating materials and imaging system components. A typical MRI system includes a cylindrical bore magnet where the patient is placed inside the magnet's tube for imaging. Next, components such as radio - frequency (RF) transmit coils (TX) and receive coils (RX) are placed on multiple sides of the patient to effectively surround the patient for imaging.

[0003] Typically, the RF-TX coil is large and completely surrounds the field of view (i.e., the imaging area), while the RF-RX coil is small and positioned directly above the field of view. In various existing MRI systems, these and other components substantially surround the patient, and their placement significantly restricts patient movement. The positioning of the RF-TX and / or RF-RX coils relative to the patient can create additional burden during patient placement into and / or removal from the imaging area. For example, the RF-RX coil is often placed directly on the patient before inserting the patient into the imaging hole of the magnet. These coils can restrict patient movement, and as a result, only the patient and a specific orientation of the coil relative to the patient can be obtained. In other MRI systems, the patient is placed between two large plates to alleviate any physical limitations on patient placement. In any case, there is a need to provide modern imaging configurations for next-generation MRI systems that further alleviate the aforementioned problems regarding patient comfort and burdensome positional limitations. [Overview of the project]

[0004] In one general embodiment, the disclosure provides a single-sided magnetoimaging apparatus comprising a permanent magnet, wherein the Z-axis is defined in the field of view through the permanent magnet. The single-sided magnetoimaging apparatus further comprises an electromagnet, a gradient coil set, a radio frequency transmission coil, a radio frequency receiving coil, and a power supply. The power supply is configured to generate an electromagnetic field in the field of view along the Z-axis. The electromagnetic field includes a field gradient in the field of view, and the adjustment of the radio frequency transmission coil is configured to target a position in the field gradient in the field of view.

[0005] In another embodiment, the Disclosure provides a method for adjusting a single-sided magnetic imaging apparatus comprising a permanent magnet, an electromagnet, a gradient coil set, a radio frequency transmitting coil, a radio frequency receiving coil, and a power supply configured to generate an electromagnetic field within a region of interest. The adjustment method includes adjusting the parameters of the radio frequency receiving coil to access a field gradient in the electromagnetic field and to target an imaging position within the field gradient. [Brief explanation of the drawing]

[0006] Novel features in various embodiments are described in detail in the attached claims. However, embodiments described in relation to both configuration and operation methods can be best understood by referring to the following description in conjunction with the attached drawings.

[0007] [Figure 1] Figure 1 is a schematic diagram of a magnetic resonance imaging system according to various embodiments of this disclosure.

[0008] [Figure 2] Figure 2 is an exploded perspective view of the magnetic resonance imaging system shown in Figure 1, relating to various aspects of this disclosure.

[0009] [Figure 3] Figure 3 is an elevation view of the magnetic resonance imaging system shown in Figure 1, relating to various embodiments of this disclosure.

[0010] [Figure 4] Figure 4 is an elevation view of the magnetic resonance imaging system shown in Figure 1, relating to various embodiments of this disclosure.

[0011] [Figure 5] Figure 5 shows exemplary patient positions for imaging by a magnetic resonance imaging system for specific surgical procedures and surgical treatments, according to various aspects of this disclosure.

[0012] [Figure 6] Figure 6 is an exemplary schematic diagram of an RF-RX array including individual coil elements and a variable magnetic field, relating to various aspects of this disclosure.

[0013] [Figure 7] Figure 7 is an exemplary diagram of a loop coil, along with exemplary variables of the loop coil magnetic field according to various aspects of this disclosure.

[0014] [Figure 8] FIG. 8 is an exemplary X - Y chart showing the magnetic field as a function of the radius of the loop coil, according to various aspects of the present disclosure.

[0015] [Figure 9] FIG. 9 is a cross - sectional view of a portion of a human body including the area around the prostate, according to various aspects of the present disclosure.

[0016] [Figure 10] FIG. 10 is an elevation view of an RF - RX array in a housing, according to various aspects of the present disclosure. For illustrative purposes, the housing is shown as a transparent component to expose the individual coil elements within the housing.

[0017] [Figure 11] FIG. 11 is another elevation view of the F - RX array of FIG. 10, according to various aspects of the present disclosure.

[0018] [Figure 12] FIG. 12 is a perspective view of the RF - RX array of FIG. 10, according to various aspects of the present disclosure.

[0019] The accompanying drawings are not intended to be drawn to scale. Corresponding reference characters indicate corresponding parts throughout several views. For clarity, not all components are shown in all the drawings. The examples described herein illustrate some embodiments of the invention in one form, and such examples should not be construed as limiting the scope of the invention in any way.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following international patent applications are hereby incorporated by reference in their entirety. · International Application PCT / US2020 / 018352 filed on February 14, 2020, titled "SYSTEMS AND METHODS FOR ULTRALOW FIELD RELAXATION DISPERSION", current international publication WO2020 / 168233 · International Application PCT / US2020 / 019530 filed on February 24, 2020, titled "SYSTEMS AND METHODS FOR PERFORMING MAGNETIC RESONANCE IMAGING", current international publication WO2020 / 172673 · International Application PCT / US2020 / 019524 filed on February 24, 2020, titled "PSEUDO-BIRDCAGE COIL WITH VARIABLE TUNING AND APPLICATIONS THEREOF", current international publication WO2020 / 172672 · International Application PCT / US2020 / 024776 filed on March 25, 2020, titled "SINGLE-SIDED FAST MRI GRADIENT FIELD COILS AND APPLICATIONS THEREOF", current international publication WO2020 / 198395 · International Application PCT / US2020 / 024778 filed on March 25, 2020, titled "SYSTEMS AND METHODS FOR VOLUMETRIC ACQUISITION IN A SINGLE-SIDED MRI SYSTEM", current international publication WO2020 / 198396 · International Application PCT / US2020 / 039667 filed on June 25, 2020, titled "SYSTEMS AND METHODS FOR IMAGE RECONSTRUCTIONS IN MAGNETIC RESONANCE IMAGING", current international publication WO2020 / 264194 · International Application PCT / US2021 / 014628 filed on January 22, 2021, titled "MRI-GUIDED ROBOTIC SYSTEMS AND METHODS FOR BIOPSY"

[0021] U.S. Patent Application Publication No. 16 / 003,585, published on June 8, 2018, entitled "UNILATERAL MAGNETIC RESONANCE IMAGING SYSTEM WITH APERTURE FOR INTERVENTIONS AND METHODOLOGIES FOR OPERATING SAME," is incorporated herein by reference in its entirety.

[0022] The following U.S. provisional patent applications are incorporated herein by reference in their entirety. U.S. Provisional Patent Application No. 62 / 987,286, filed on March 9, 2020, entitled "SYSTEMS AND METHODS FOR ADAPTING DRIVEN EQUILIBRIUM FOURIER TRANSFORM FOR SINGLE-SIDED MRI". U.S. Provisional Patent Application No. 62 / 987,292, filed on March 9, 2020, entitled "SYSTEMS AND METHODS FOR LIMITING K-SPACE TRUNCATION IN A SINGLE-SIDED MRI SCANNER".

[0023] Before describing in detail various aspects of the MRI systems and methods, it should be noted that the exemplary embodiments are not limited to their application or use in the details of the configuration and arrangement of components illustrated in the accompanying drawings and descriptions. The exemplary embodiments may be implemented or incorporated in other aspects, variations, and modifications, and may be implemented or performed in various ways. Furthermore, unless otherwise specified, the terms and expressions used herein have been selected for the purpose of illustrating the exemplary embodiments for the convenience of the reader and are not intended to limit them. It will also be understood that one or more of the aspects, expressions of aspects, and / or embodiments described below may be combined with any or more of the other aspects, expressions of aspects, and / or embodiments described below.

[0024] A typical MRI system creates a uniform field within the imaging area. This uniform field then generates a narrow band of magnetic resonance frequencies that can be captured and amplified by a receiving coil (RF-RX) and digitized by a spectrometer. Because the frequencies are within a narrow and clearly defined bandwidth, the hardware architecture focuses on creating statically tuned RF-RX coils with optimal coil quality factors. Many variations of coil architecture have been fabricated, exploring large single-volume coils, coil arrays, parallel coil arrays, or object-specific coil arrays. However, these structures presuppose imaging at high electric field strengths and specific frequencies close to interest, and are as small as possible to fit within the magnetic bore or tube of an enclosed MRI apparatus.

[0025] In various embodiments, the MRI system is provided to include a unique imaging region that can be offset from the surface of the magnet. Such offset and unidirectional MRI systems are less restrictive compared to conventional MRI scanners. Furthermore, this shape factor can have an embedded or inherent magnetic field gradient that produces a wide range of magnetic field values ​​across the region of interest. Moreover, because the system can operate at lower magnetic field strengths compared to typical MRI systems, the design constraints on the RX coil are relaxed, and / or additional mechanisms, such as robotics, can be used with the MRI scanner. An exemplary MRI-guided robotic system is further described, for example, in International Application PCT / US2021 / 014628, filed on January 22, 2021, entitled "MRI-GUIDED ROBOTIC SYSTEMS AND METHODS FOR BIOPSY".

[0026] The inherent architecture of the principal magnetic field of an MRI system according to various embodiments of this disclosure can create different sets of optimization constraints. Because the imaging volume spans a wider range of magnetic resonance frequencies, the hardware can be configured to be highly sensitive to and capture specific frequencies generated across the field of view. This frequency spread is typically much larger than what a single receiving coil tuned to a single frequency can sense. Furthermore, since the field strength can be much lower than in conventional systems, and the signal strength can be proportional to the field strength, it is generally considered beneficial to maximize the signal-to-noise ratio (SNR) of the receiving coil network. Thus, methods are provided, according to various embodiments, for acquiring the full range of frequencies generated within the field of view without loss of sensitivity.

[0027] Figures 1-5 show a magnetic resonance imaging system 100. As shown in Figures 1 and 2, the magnetic resonance imaging system 100 includes a housing 120. The housing 120 includes a front surface 125. According to various embodiments, the front surface 125 may be a concave and / or recessed front surface.

[0028] As shown in Figures 1 and 2, the housing 120 includes a permanent magnet 130, a radio frequency transmitting coil 140, a gradient coil set 150, an electromagnet 160, and a radio frequency receiving coil 170. As shown in Figures 3 and 4, the permanent magnet 130 may include a plurality of magnets arranged in an array configuration. The plurality of magnets forming the permanent magnet 130 are configured to cover an entire surface, as shown in the front view of Figure 3, and to be shown as lateral bars, as shown in the side selection view of Figure 4. Referring mainly to Figure 1, the main permanent magnet array may have at least one access opening or bore 135, thereby allowing access to the patient through the housing 120 from the opposite side of the housing 120. In other aspects of the present disclosure, the array of permanent magnets may be boreless and may define an uninterrupted arrangement of boreless permanent magnets defined therethrough.

[0029] According to various embodiments of this disclosure, the permanent magnet 130 provides a static magnetic field within the region of interest 190. According to various embodiments, the permanent magnet 130 may include a plurality of cylindrical permanent magnets in a parallel configuration, as shown in Figures 3 and 4. For example, the permanent magnet assembly 130 may include, but is not limited to, rare-earth magnetic materials such as neodymium-based magnetic materials, and may include any suitable magnetic material.

[0030] According to various embodiments of the magnetic resonance imaging system 100 illustrated in Figures 1-4, the patient can be positioned in any number of different positions depending on the type of anatomical scan. As an example, when the pelvis is scanned with the magnetic resonance imaging system 100, as shown in Figure 5, the patient can be placed on a surface in a lithotomy position. As illustrated in Figure 5, in the case of a pelvic scan, the patient can be positioned with their back on a table and their legs raised and placed on top of the system 100. The pelvic region can be positioned just in front of the bore 135.

[0031] In various embodiments, several methods are provided that can enable imaging within the MRI system 100. These methods may include combining one or more of the following: a variably tuned RF-RX coil, an RF-RX coil array having elements tuned to frequencies dependent on spatial non-uniformity of the magnetic field, an ultra-low-noise preamplifier design, and an RF-RX array having multiple receiving coils designed to optimize signals from a defined and limited field of view for a particular object portion. These methods can be combined in any combination as needed.

[0032] In various aspects of this disclosure, a variable-adjustment RF-RX coil may be incorporated into an MRI system 100. For example, a radio frequency receiving coil 170 may include a variable-rotation RF-RX coil. The variable-rotation RF-RX coil may include one or more electronic components for adjusting the electromagnetic receiving field. In various implementations, one or more electronic components may include at least one of a varactor, a PIN diode, a capacitor, an inductor, a MEMS switch, a solid-state relay, or a mechanical relay. In various implementations, one or more electronic components used for adjustment may include at least one of a dielectric, a capacitor, an inductor, a conductive metal, a metamaterial, or a magnetic metal. In various implementations, adjustment of the electromagnetic receiving field can be achieved using different methods, such as a voltage adjustment method that changes the voltage to activate the components, or a physical repositioning method that changes the physical position of one or more electronic components to adjust their capacitance or inductance characteristics.

[0033] Voltage regulation methods involve using passive devices with switching capabilities. The most commonly used device for this purpose is the PIN diode. By applying a forward voltage, the PIN diode is biased forward, which means the PIN diode turns on, thereby allowing current to pass to the connected device. This method can be useful for selectively turning on a coil by sending a forward voltage to the coil to be used. However, a disadvantage of this method is that the PIN diode is considerably more expensive than the actual receiving coil and tends to break during transmission due to voltage spikes from the TX coil. Physical repositioning methods require physically moving the coil to alter its inductive and capacitive characteristics. Because this process involves the physical movement of the coil, in certain cases it can place an additional burden on the patient during scanning. Both methods adjust the inherent resonant frequency or coil bandwidth.

[0034] In various implementations, coils are cooled to low temperatures to reduce resistance and improve efficiency.

[0035] In various aspects of this disclosure, the MRI system 100 may include an RF-RX array comprising individual coil elements tuned to various frequencies. The appropriate frequency can be selected, for example, to match the frequency of a magnetic field located at a specific spatial location where a particular coil is situated.

[0036] Referring here to schematic diagram 300 in Figure 6, the RF-RX array 308 and magnetic field 310 are shown. The magnetic field 310 can vary as a function of space, and the magnetic fields and frequencies of coils 302, 304, and 306 of the RF-RX array 308 can be adjusted to approximately coincide with spatial positions. Here, coils 302, 304, and 306 may be designed to image field positions B1, B2, and B3, which are physically separated along a single axis B0 in the Z direction. In Figure 6, coils 302, 304, and 306 overlap with adjacent coils, as shown by ellipses intersecting each other.

[0037] The RF-RX array 308 in Figure 6 can be incorporated into the magnetic imaging system 100. For example, the radio frequency receiving coil 170 may further include an RF-RX array that is adjustable along the Z-axis.

[0038] For low-magnetic-field systems such as System 100, a low-noise preamplifier may be designed and configured to take advantage of the low-signal environment of the MRI system. This low-noise amplifier can be configured to utilize components that do not generate significant electronic and voltage noise at desired frequencies (e.g., <4 MHz and >2 MHz). When there is an input signal to the preamplifier, the signal and noise are amplified by the preamplifier by an equal amount (gain). To obtain useful low-noise amplification, the signal amplitude should be high while maintaining low noise. To keep noise to a minimum, the signal-to-noise ratio (SNR) of the preamplifier must be high. One way to achieve a good SNR while keeping the noise level low is to add an operational amplifier (op-amp) in parallel. Typical junction field-effect transistor (J-FET) designs generally do not have good noise characteristics at this frequency and can produce high-frequency instability in the GHz range, which can leak into the measured frequency range, albeit at a lower level of several tens of dB. The system gain is preferably >80 dB overall, for example, so that any small instability or inherent electrical noise can be amplified and degrade the integrity of the signal.

[0039] In various aspects of this disclosure, an RF-RX coil may be designed to image a specific, limited field of view based on a target anatomical structure. For example, referring to Figure 9, Figure 600, the prostate gland is located at a depth of approximately 60 millimeters within the human body. To design an RF-RX coil for prostate imaging, the coil must be configured to enable imaging at a depth of 60 mm within the human body. Referring to the variables and schematic coil diagram 500 in Figure 7, according to the Biot-Savart method, the magnetic field of the loop coil can be calculated by the following equation:

number

[0040] A low-impedance preamplifier design with an input impedance of less than 5 ohms can be used in series with a coil matching network in a receiving coil array to provide active decoupling from adjacent coils in the same array. This technique does not rely on geometric decoupling to release the mutual conductance between coils, but allows individual coils in the array to be decoupled from one another using the low-noise preamplifier itself. Each coil in the receiving coil array has an inductive and capacitive matching network used to match the coil's resistance to 50 ohms for maximum power transfer. When the low-impedance preamplifier is connected to the coil matching network, the low impedance acts as a short circuit, thereby making the observed impedance in the coil infinite and trapping any coil current.

[0041] Based on the geometric constraints of the human body, loop coils can be placed in the space between the legs on the torso. Therefore, installing a coil with a diameter of 170 mm in that location is not impossible, but extremely difficult. As shown in Figure 8, when R is less than 85 mm, the Bz field value increases with respect to the loop radius. Therefore, it is advantageous to make the coil as large as possible. For example, the largest loop coil that can be placed between human legs has a diameter of approximately 10 cm.

[0042] Because the size of the coil can generally be limited by space, such as between a person's legs, the magnetic field of a 10 cm diameter coil generally cannot reach the depth of the prostate. Therefore, for example, a single coil may not be sufficient to image the prostate. Thus, in this case, multiple coils may prove beneficial in acquiring signals from different directions. In various embodiments of MRI systems, the magnetic field is provided in the z direction, and the RF coil is highly sensitive to the x and y directions. In this exemplary case, a loop coil in the xy plane cannot collect an RF signal from a person because it is highly sensitive in the z direction, but in this case, a butterfly coil can be used. Then, based on position and orientation, the RF coil can be a loop coil or a butterfly coil. Furthermore, the coil can be placed under the main body, and there are no limitations on its size. Figures 10-12, further described herein, show, for example, an RF array 700 including combinations of different types of coils.

[0043] For the needs of multiple RX coils, in various embodiments of this disclosure, isolation between them may prove beneficial to various aspects of MRI system RX coil arrays. In these cases, each coil can be isolated from the others, and isolation techniques may include, for example, 1) shape isolation, 2) capacitance / inductive decoupling, and 3) low / high impedance preamplifier coupling.

[0044] Geometric decoupling may be the simplest decoupling technique because it does not involve any active or passive circuit elements to achieve the desired decoupling. Each coil in a receiving coil array is a transmitting wire, meaning each coil has its own self-induction and mutual induction. When a receiving coil is excited by a voltage, it generates a magnetic field that is effectively "visible" by any coil adjacent to it, which then generates noise. To reduce this effect, the coils are arranged geometrically such that the mutual conductance between them is lowest. The drawback of this method is that the coils are constrained by their geometric shape, and any additional movement or manipulation of the coil's geometric shape (e.g., by bending) changes the conductance of the coils and their mutual conductance, which leads to changes in decoupling.

[0045] An MRI system, according to various embodiments, can have a deformable magnetic field from a magnet, the intensity of which can change linearly along the z-direction. The RX coils can be positioned at different locations in the z-direction, and each coil can be tuned to a different frequency depending on its position within the system.

[0046] Based on the simplicity of a single coil loop, these coils can be constructed from simple conductive traces that are pre-tuned to a desired frequency and can be printed, for example, on disposable substrates. This inexpensive fabrication technique allows clinicians to place RX coils (or coil arrays) on a body in a given area of ​​interest for a given procedure and then discard the coils. These coils can be constructed, for example, from 3D printed copper, silver, or other conductive inks on plastic or woven material. Alternatively, conductive wires can be woven into a fabric to create coils that are resistant to deformation. For example, an RX coil may be a surface coil that can be worn or taped to the patient's body. For example, for certain body parts such as the ankle or wrist, the surface coil may be a single loop, a figure-eight design, or a butterfly coil wound around the area of ​​interest. For example, for areas requiring significant penetration depth, such as the torso or knee, the coil may consist of a Helmholtz coil pair. As with receiving coils in other MRI systems, the coils are optimally sensitive to planes perpendicular to the principal magnetic field B0 of the axis in Figure 6.

[0047] In some embodiments, the coil may be inductively coupled to another loop electrically connected to the receiving preamplifier. This design would allow for easier and unobstructed access to the receiving coil. In receiving coils from other MRI systems, a preamplifier may be located on the coil to reduce any signal loss due to cable loss, insertion loss, etc. This also means that the preamplifier is located near or in contact with the patient, thereby causing electrical interference. By moving the receiving preamplifier away from the receiving coil, it is possible for the patient to have unobstructed access to the receiving coil in various embodiments of this disclosure.

[0048] According to various aspects of this disclosure, the size of the coil may be limited by the structure of the human body. For example, the size of the coil should be positioned and configured to fit within the space between a person's legs when imaging the prostate gland.

[0049] Referring to Figures 10-12, the RF-RX array 700 is shown. The RF-RX array 700 is located within a housing or enclosure 702 that accommodates the different coils that make up the RF-RX array 700. In the exemplary embodiment shown in Figures 10-12, the RF-RX array 700 comprises five coils 704, 706, 708, 710, and 712. The coils 704, 706, 708, 710, and 712 are butterfly coils containing a pair of lobes. The first coil 704 forms a first lobe or loop at the top of the array and a second lobe or loop in the central part of the array. The first loop of the first coil 704 surrounds the second coil 706. The second loop of the first coil 704 surrounds a through-hole 714 in the enclosure 702. The second coil 706 is located above the through-hole 714. The third coil 708 extends around the upper half of the through-hole 714. The fourth coil 710 extends around the lower half of the through-hole 714. The ends of the loops of the third and fourth coils 708 and 710 overlap at a vertical centerline through the through-hole 714. The first coil 704 also overlaps / underlaps portions of the second coil 706, the third coil 708, and the fourth coil 710. The fifth coil 712 is positioned along the bottom of the enclosure 702 below the through-hole 714. All of the coils 704, 708, 710, and 712 overlap each other within the region such that at least a portion of each coil is positioned over a portion of the other coils, forming an overlapping array.

[0050] The enclosure 702 also defines a curve, as best shown in Figure 11. In other embodiments, the enclosure 702 and the coils within it may define one or more different radii of curvature. Different numbers of coils may be included in alternative RF-RX arrays, and / or the coils may include, for example, different shapes and / or sizes. [Examples]

[0051] Various aspects of the subject matter described herein are shown in the following numbered examples.

[0052] Example 1 A single-sided magnetoimaging apparatus comprising a permanent magnet, wherein the Z-axis is defined within the field of view through the permanent magnet. The single-sided magnetoimaging apparatus further comprises an electromagnet, a gradient coil set, a radio frequency transmission coil, a radio frequency receiving coil, and a power supply. The power supply is configured to generate an electromagnetic field within the field of view along the Z-axis. The electromagnetic field includes a field gradient within the field of view, and the adjustment of the radio frequency transmission coil is configured to target a position within the field gradient within the field of view.

[0053] Example 2 The adjustment of the radio frequency transmission coil includes repositioning the radio frequency transmission coil along the Z-axis, as described in Embodiment 1 of the single-sided magnetic imaging apparatus.

[0054] Example 3 The single-sided magnetic imaging apparatus according to Example 1 or 2, wherein the adjustment of the radio frequency transmitting coil includes adjusting the current supplied to the radio frequency receiving coil.

[0055] Example 4 The adjustment of the radio frequency transmission coil includes rearranging at least one electronic component selected from the group consisting of varactors, pin diodes, capacitors, inductors, MEMS switches, solid-state relays, and mechanical relays, as described in Example 1, 2, or 3 of the single-sided magnetic imaging apparatus.

[0056] Example 5 The single-sided magnetic imaging apparatus according to Example 1, 2, 3, or 4, wherein the radio frequency receiving coil includes a coil printed on a disposable substrate.

[0057] Example 6 The radio frequency receiving coil is an array of radio frequency receiving coils, as described in Example 1, 2, 3, 4, or 5 of the single-sided magnetic imaging apparatus.

[0058] Example 7 The array of radio frequency receiving coils comprises a first coil and a second coil, and the first coil and the second coil are separated, in the single-sided magnetic imaging apparatus of Embodiment 6.

[0059] Example 8 A single-sided magnetic imaging apparatus according to Embodiment 6 or 7, wherein the array of radio frequency receiving coils comprises a first coil and a second coil, the first coil and the second coil being positioned to receive signals from different directions.

[0060] Example 9 A single-sided magnetic imaging apparatus according to Example 7 or 8, wherein the first coil and the second coil have different shapes.

[0061] Example 10 A single-sided magnetic imaging apparatus according to Embodiments 6, 7, 8, or 9, wherein the array of radio frequency receiving coils comprises a first coil and a second coil, the first coil and the second coil being arranged alternately in the longitudinal direction along the Z-axis.

[0062] Example 11 The first coil and the second coil partially overlap in the single-sided magnetic imaging apparatus according to Examples 7, 8, 9, or 10.

[0063] Example 12 A single-sided magnetic imaging apparatus according to Examples 7, 8, 9, 10, or 11, wherein the first coil and the second coil are tuned to different frequencies.

[0064] Example 13 A single-sided magnetic imaging apparatus according to Embodiments 7, 8, 9, 10, 11, or 12, wherein the first coil is tuned to correspond to a first frequency of the field gradient at a position along the Z-axis, and the second coil is tuned to match a second frequency of the field gradient at a second position along the Z-axis.

[0065] Example 14 A single-sided magnetic imaging apparatus according to Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, and 13, further comprising a housing including a concave outer surface, wherein the permanent magnet is positioned within the housing, and the field of view is outside the housing and offset from the concave outer surface.

[0066] Example 15 A method for adjusting a single-sided magnetic imaging apparatus, comprising a permanent magnet, an electromagnet, a gradient coil set, a radio frequency transmitting coil, a radio frequency receiving coil, and a power supply configured to generate an electromagnetic field within a region of interest. The adjustment method includes adjusting the parameters of the radio frequency receiving coil to access the field gradient within the electromagnetic field and to target an imaging position within the field gradient.

[0067] Example 16 The method according to Example 15, which includes adjusting the parameters of the radio frequency receiving coil to target the imaging position within the field gradient, and rearranging the radio frequency transmitting coil.

[0068] Example 17 The method according to Example 15 or 16, wherein adjusting the parameters of the radio frequency receiving coil to target an imaging position within a field gradient includes adjusting the current supplied to the radio frequency receiving coil.

[0069] Example 18 The method according to Examples 15, 16, or 17, wherein adjusting the parameters of the radio frequency receiving coil to target an imaging position within a field gradient involves rearranging at least one electronic component selected from the group consisting of varactors, pin diodes, capacitors, inductors, MEMS switches, solid-state relays, and mechanical relays.

[0070] Example 19 The method according to Examples 15, 16, 17, or 18, which includes the step of adjusting the parameters of the radio frequency receiving coil to target an imaging position within a field gradient, by adjusting the radio frequency receiving coil to a predetermined frequency based on a target anatomical structure.

[0071] Example 20 The method according to Examples 15, 16, 17, 18, or 19, wherein the magnetic imaging apparatus includes an array of radio frequency receiving coils, and the adjustment method further includes adjusting the coils in the array of radio frequency coils to different frequencies.

[0072] While several forms are illustrated and described, it is not the applicant's intention to limit or restrict the attached claims to such detail. Numerous modifications, variations, alterations, substitutions, combinations, and equivalents of those forms may be carried out and will be conceived by those skilled in the art without departing from the scope of this disclosure. Furthermore, the structure of each element relating to the described forms can alternatively be described as a means for providing the function performed by the element. Also, if a material is disclosed for a particular component, other materials may be used. Therefore, it should be understood that the foregoing description and the attached claims are intended to cover all such modifications, combinations, and variations as falling within the scope of the disclosed forms. The attached claims are intended to cover all such modifications, variations, alterations, substitutions, alterations, and equivalents.

[0073] The detailed descriptions above have described various forms of devices and / or processes by using block diagrams, flowcharts, and / or embodiments. Where such block diagrams, flowcharts, and / or embodiments include one or more functions and / or operations, it will be understood by those skilled in the art that each function and / or operation of such block diagrams, flowcharts, and / or embodiments can be performed individually and / or collectively by a variety of hardware, software, firmware, or substantially any combination thereof. Those skilled in the art will recognize that some aspects of the forms disclosed herein can be equivalently implemented in an integrated circuit as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or substantially any combination thereof, and that designing circuits and / or writing code for software and / or firmware would be sufficient within the scope of the skills of those skilled in the art in light of this disclosure. Furthermore, those skilled in the art will understand that the mechanisms of the subject matter described herein can be assigned as one or more program products in various forms, and that the exemplary forms of the subject matter described herein are applicable regardless of the specific type of signal-carrying medium actually used for assignment.

[0074] Instructions used to program logic and execute various disclosed embodiments may be stored in system memory, such as dynamic random access memory (DRAM), cache, flash memory, or other storage. Furthermore, instructions may be assigned via a network or other computer-readable medium. Thus, machine-readable media may include, but are not limited to, any mechanism for storing or transmitting information in a machine-readable format, such as floppy disks, optical disks, compact disks, read-only memory (CD-ROMs), and magneto-optical disks, read-only memory (ROMs), random access memory (RAMs), erasable programmable read-only memory (EPROMs), electrically erasable programmable read-only memory (EEPROMs), magnetic or optical cards, flash memory, or tangible machine-readable storage used for transmitting information over the Internet via electrical, optical, acoustic, or other forms of propagating signals (e.g., carrier waves, infrared signals, digital signals, etc.). Thus, non-temporary computer-readable media include any type of tangible machine-readable medium suitable for storing or transmitting electronic instructions or information in a machine-readable format.

[0075] As used in any aspect of this specification, the term “control circuit” can refer to, for example, wired circuits, programmable circuits (e.g., computer processors including one or more individual instruction processing cores, processing units, processors, microcontrollers, microcontroller units, controllers, digital signal processors (DSPs), programmable logic devices (PLDs), programmable logic arrays (PLAs), or field-programmable gate arrays (FPGAs), state machine circuits, firmware storing instructions executed by programmable circuits, and any combination thereof. Control circuits can be embodied collectively or individually as circuits forming part of a larger system, such as an integrated circuit (IC), an application-specific integrated circuit (ASIC), a system-on-a-chip (SoC), a desktop computer, a laptop computer, a tablet computer, a server, a smartphone, etc. Therefore, as used herein, “control circuit” can refer to, for example, wired circuits, programmable circuits (e.g., computer processors including one or more individual instruction processing cores, and processing units, processors, microcontrollers, microcontroller units, controllers, digital signal processors (DSPs), programmable logic devices (PLDs), programmable logic arrays (PLAs), or field-programmable gate arrays (FPGAs), state machine circuits, firmware storing instructions executed by programmable circuits, and any combination thereof. "Subject matter" includes, but is not limited to, an electrical circuit having at least one discrete electrical circuit, an electrical circuit having at least one integrated circuit, an electrical circuit having at least one application-specific integrated circuit, an electrical circuit forming a general-purpose computing device configured by a computer program (e.g., a general-purpose computer configured by a computer program that performs at least part of the processes and / or devices described herein, or a microprocessor configured by a computer program that performs at least part of the processes and / or devices described herein), an electrical circuit forming a memory device (e.g., in the form of random access memory), and an electrical circuit forming a communication device (e.g., a modem, a communication switch, or an optical electrical device). Those skilled in the art will recognize that the subject matter described herein can be performed in analog or digital manner or in some combination thereof.

[0076] As used in any aspect of this specification, the term “logic” may refer to an app, software, firmware, and / or circuit configured to perform any of the operations described above. Software can be embodied as a software package, code, instructions, instruction sets, and / or data recorded on a non-temporary computer-readable storage medium. Firmware can be embodied as hardcoded (e.g., non-volatile) code, instructions, or instruction sets, and / or data within a memory device.

[0077] The terms “component,” “system,” “module,” etc., used in any aspect of this specification may refer to computer-related entities that are hardware, a combination of hardware and software, software, or running software.

[0078] As used in any aspect of this specification, “algorithm” refers to a self-consistent sequence of steps leading to a desired result, and “step” refers to the manipulation of physical quantities and / or logical states that can take the form of electrical or magnetic signals that can be manipulated in ways that are not necessarily required, such as by being stored, transmitted, combined, compared, and otherwise manipulated. These signals are commonly referred to as bits, values, elements, symbols, characters, terms, numbers, etc. These terms and similar terms may be associated with preferred physical quantities and are merely convenient designations applied to these quantities and / or states.

[0079] Networks may include packet-switched networks. Communication devices may be able to communicate with each other using a selected packet-switched network communication protocol. One exemplary communication protocol may include the Ethernet communication protocol, which can enable communication using the Transmission Control Protocol / Internet Protocol (TCP / IP). The Ethernet protocol may conform to or be compatible with the Ethernet standard published by the Institute of Electrical and Electronics Engineers (IEEE) in December 2008, entitled "IEEE 802.3 Standard," and / or any later versions of this standard. Alternatively or additionally, communication devices may communicate with each other using the X.25 communication protocol. The X.25 communication protocol may conform to or be compatible with standards published by the Telecommunication Standardization Sector (ITU-T) of the International Telecommunication Union. Alternatively or additionally, communication devices may communicate with each other using the Frame Relay communication protocol. The Frame Relay communication protocol may conform to or be compatible with standards published by the International Telecommunication Consultative Committee (CCITT) and / or the American National Standards Institute (ANSI). Alternatively or additionally, transceivers can communicate with each other using the Asynchronous Transfer Mode (ATM) communication protocol. The ATM communication protocol may conform to or be compatible with the ATM standard published by the ATM Forum in August 2001, entitled "ATM-MPRS Network Interworking 2.0," and / or any later versions thereof. Of course, different and / or later developed connection-type network communication protocols are also assumed herein.

[0080] Unless otherwise noted, as is evident from the foregoing disclosures, any use of terms such as “process,” “calculate,” “calculate,” “determine,” and “display” throughout the foregoing disclosures is understood to refer to the operations and processing of a computer system or similar electronic computing device that manipulates and converts data, which is represented as a physical (electronic) quantity in the registers and memory of a computer system, into other data, which is similarly represented as a physical quantity in the memory or registers of a computer system or in any other information storage, transmission, or display device.

[0081] In this specification, one or more components may be referred to as “configured to,” “configurable to,” “operable to,” “adaptable to,” “suitable to,” etc. Those skilled in the art will recognize that “configured to” can usually include active components and / or inactive components and / or standby components, unless otherwise required by the context.

[0082] The terms “proximal” and “distal” are used herein in reference to the clinician’s operation of the handle or housing portion of a surgical instrument. “Proximal” refers to the portion closest to the clinician and / or the robotic arm, while “distal” refers to the portion located further away from the clinician and / or the robotic arm. Furthermore, for convenience and clarity, spatial terms such as “vertical,” “horizontal,” “up,” and “down” may be used herein in reference to the drawings. However, robotic surgical instruments are used in many orientations and positions, and these terms are not intended to be restrictive and / or absolute.

[0083] Those skilled in the art will generally recognize that the terminology used, particularly in the appended claims (e.g., the body of the appended claims), is usually intended as “open” terminology (for example, the term “contains” should be interpreted as “contains but not limited to,” the term “has” should be interpreted as “has at least,” and the term “equipped” should be interpreted as “equipped but not limited to,” etc.). If a certain number of introduced claim subjects are intended, such intent will be explicitly stated in the claims, and if such statement is not present, it will be understood by those skilled in the art that such intent does not exist. For example, for the sake of understanding, the following appended claims may include the use of the introductory phrases “at least one” and “one or more” to introduce the subject matter of the claims. However, the use of such phrases should not be interpreted as meaning that the introduction of a claim description by the indefinite article "a" or "an" restricts any particular claim containing such introduced description to claims containing only one such description, even if the same claim contains the introductory phrase "one or more" or "at least one" and an indefinite article, e.g., "a" or "an" (e.g., "a" and / or "an" should generally be interpreted as meaning "at least one" or "one or more"). The same applies to the use of the definite article used to introduce a claim description.

[0084] Furthermore, even when a specific number of introduced claims are explicitly stated, a person skilled in the art will recognize that such a statement should typically be interpreted as meaning at least the stated number (for example, a statement of only "two statements" without other modifiers typically means at least two statements, or more than two statements). Moreover, in those examples where conventions similar to "at least one of A, B, and C, etc." are used, such a construction is generally intended to mean that a person skilled in the art will understand the convention (for example, "a system having at least one of A, B, and C" means a system having only A, only B, only C, a combination of A and B, a combination of A and C, a combination of B and C, and / or a combination of A, B, and C, etc., but not limited to these). In those examples where a convention similar to “at least one of A, B, and C, etc.” is used, such a configuration is generally intended to mean that a person skilled in the art will understand the convention (for example, “a system having at least one of A, B, or C” includes, but is not limited to, a system having A only, B only, C only, a combination of A and B, a combination of A and C, a combination of B and C, and / or a combination of A, B, and C, etc.). A person skilled in the art will further understand that, typically in the description, claims, or drawings, disjunct words and / or phrases presenting two or more alternative terms should be understood to assume the possibility of including one of the terms, either of the terms, or both, unless otherwise indicated in the context. For example, the phrase “A or B” will usually be understood to include the possibilities of “A” or “B” or “A and B”.

[0085] Those skilled in the art will understand that, with respect to the attached claims, the steps described herein may generally be performed in any order. Furthermore, while various process flow charts are shown sequentially, it should be understood that the various steps may be performed in orders other than those exemplified, or simultaneously. Examples of such alternative orders include overlapping, intermittent, interrupted, reordering, augmentation, preparatory, supplementary, simultaneous, reverse, or other variations in ordering, unless otherwise indicated by the context. Moreover, terms such as “responding to,” “related to,” or other past tense adjectives, etc., are not usually intended to exclude such variations unless otherwise indicated by the context.

[0086] Please note that when we refer to "one aspect," "a certain aspect," "a certain example," or "an example," we mean that the specific features, structures, or characteristics described in relation to that aspect are included in at least one aspect. Therefore, the phrases "in one aspect," "in a certain aspect," "in a certain example," and "in an example," found throughout this specification, do not necessarily all refer to the same aspect. Furthermore, specific features, structures, or characteristics may be combined in one or more aspects in any preferred manner.

[0087] Any patent application, patent, non-patent publication, or other disclosure material referred to herein and / or contained in any application data sheet is incorporated herein by reference to the extent that the incorporated material does not conflict with this specification. To that extent, and to the extent necessary, the express disclosures expressed herein supersede any conflicting material incorporated herein by reference. Any material or any part thereof that is said to be incorporated herein by reference but conflicts with any existing definitions, statements, or other disclosure material contained herein is incorporated only to the extent that no conflict arises between the incorporated material and the existing disclosure material.

[0088] In summary, the numerous advantages arising from adopting the concepts described herein have been explained. The above-mentioned descriptions of one or more forms are presented for illustrative and explanatory purposes only. They are not intended to exhaust or limit the exact forms disclosed. Modifications or variations are possible from the perspective of the above teachings. One or more forms have been selected and described to illustrate the principle and practical application, so that a person skilled in the art can utilize various modified forms as suitable for a particular intended use. The claims submitted herein are intended to define the overall scope.

Claims

1. 1. A single-sided magnetic imaging device, comprising: a permanent magnet, the permanent magnet being configured to generate a static magnetic field in the Z-axis, the Z-axis being defined to extend perpendicular to the permanent magnet and into a field of view; a radio frequency transmit coil configured to generate an electromagnetic field in the target; a variably tuned radio frequency receiving coil configured to detect magnetic flux within the target responsive to the electromagnetic field; the variably tuned radio frequency receiving coil is further configured to be tuned to a plurality of frequencies to match the frequency of an electromagnetic field at a location. Single-sided magnetic imaging device.

2. The single-sided magnetic imaging device of claim 1 , wherein adjusting the radio frequency receive coil comprises repositioning the radio frequency transmit coil along the Z-axis.

3. 2. The single-sided magnetic imaging device of claim 1, wherein adjusting the radio frequency receiving coil comprises adjusting a current supplied to the radio frequency receiving coil.

4. 10. The single-sided magnetic imaging device of claim 1, wherein tuning the radio frequency receiving coil comprises rearranging at least one electronic component selected from the group consisting of varactors, pin diodes, capacitors, inductors, MEMS switches, solid state relays, and mechanical relays.

5. The single-sided magnetic imaging device of claim 1 , wherein the radio frequency receiving coil comprises a coil printed on a disposable substrate.

6. The single-sided magnetic imaging device of claim 1 , wherein the radio frequency receive coil comprises an array of radio frequency receive coils.

7. 7. The single-sided magnetic imaging device of claim 6, wherein the array of radio frequency receive coils comprises a first coil and a second coil, the first coil and the second coil being separated.

8. 7. The single-sided magnetic imaging device of claim 6, wherein the array of radio frequency receive coils comprises a first coil and a second coil, the first coil and the second coil positioned to receive signals from different directions.

9. The single-sided magnetic imaging device of claim 8 , wherein the first coil and the second coil comprise different shapes.

10. 7. The single-sided magnetic imaging device of claim 6, wherein the array of radio frequency receiving coils comprises a first coil and a second coil, the first coil and the second coil being aligned longitudinally with the Z-axis and offset in the longitudinal direction.

11. The single-sided magnetic imaging device of claim 10 , wherein the first coil and the second coil partially overlap.

12. The single-sided magnetic imaging device of claim 10 , wherein the first coil and the second coil are tuned to different frequencies.

13. 11. The single-sided magnetic imaging device of claim 10, wherein the first coil is tuned to correspond to a first frequency of the electromagnetic field at the location along the Z axis and the second coil is tuned to match a second frequency of the electromagnetic field at a second location along the Z axis.

14. 2. The single-sided magnetic imaging device of claim 1 further comprising a housing having a concave outer surface, said permanent magnet being positioned within said housing, said field of view being exterior to said housing and offset from said concave outer surface.

15. A method for adjusting a single-sided magnetic imaging device, comprising the steps of: generating a static magnetic field in a Z-axis direction by a permanent magnet; generating an electromagnetic field in a region of interest with a radio frequency transmit coil; and adjusting parameters of a radio frequency receive coil to target an imaging location within the field gradient of the electromagnetic field.

16. 16. The method of claim 15, wherein adjusting the parameters of the radio frequency receive coil to target an imaging location within the field gradient comprises repositioning the radio frequency transmit coil.

17. 16. The method of claim 15, wherein adjusting the parameters of the radio frequency receive coil to target an imaging location within the field gradient comprises adjusting a current supplied to the radio frequency receive coil.

18. 16. The method of claim 15, wherein adjusting the parameters of the radio frequency receive coil to target an imaging location within the field gradient comprises rearranging at least one electronic component selected from the group consisting of varactors, pin diodes, capacitors, inductors, MEMS switches, solid state relays, and mechanical relays.

19. 16. The method of claim 15, wherein adjusting the parameters of the radio frequency receive coil to target an imaging location within the field gradient comprises tuning the radio frequency receive coil to a predetermined frequency based on anatomy of the target.

20. The method of claim 15 , wherein the magnetic imaging device comprises an array of radio frequency receive coils, and the tuning method further comprises tuning the coils in the array of radio frequency receive coils to different frequencies.

Images