Automatic fail-safe logic monitoring temperature

Abstract

A portable magnetic resonance (MR) imaging system is disclosed, including a housing including an array of magnets, a radio frequency (RF) coil assembly, a RF power amplifier, a primary control circuit and a safety control circuit. The RF power amplifier is configurable from a default configuration to an enabled configuration. The system can further include a thermocouple positioned to monitor a temperature.

Description

PATENT Attorney Docket No.230094PCT TITLE AUTOMATIC FAIL-SAFE LOGIC MONITORING TEMPERATURE BACKGROUND

[0001] The present disclosure relates to magnetic resonance imaging (MRI), medical imaging, medical intervention, and surgical intervention. MRI systems often include large and complex machines that generate significantly high magnetic fields and create significant constraints on the feasibility of certain surgical interventions. Restrictions can include limited physical access to the patient by a surgeon and / or a surgical robot and / or limitations on the usage of certain electrical and mechanical components in the vicinity of the MRI scanner. Such limitations are inherent in the underlying design of many existing systems and are difficult to overcome. SUMMARY

[0002] In one general aspect, the present disclosure describes a portable magnetic resonance (MR) imaging system, including a housing. The housing including an array of magnets positioned to project a low-field strength magnetic field into a region of interest, and a radio frequency (RF) coil assembly configured to selectively excite magnetization in the region of interest. The portable MR imaging system further includes an electronic device, a thermocouple positioned to monitor a temperature in the housing, a primary control circuit in signal communication with the thermocouple, and a safety control circuit in signal communication with the electronic device and the primary control circuit. The safety control circuit is to receive, from the primary control circuit, a temperature signal indicative of the temperature detected by the thermocouple, receive, from the electronic device, a status signal indicative of an operational parameter of the electronic device, and provide an electronic notification, via an interface, based on a condition. The condition is selected from a group consisting of the operational parameter being outside a predetermined range of values and the temperature being outside a predefined range of temperatures. The safety control circuit is further to transmit a stop scan signal to the primary control circuit based on the electronic notification being provided to the interface.

[0003] In another general aspect, the present disclosure describes a method of operating a portable MR imaging system including a housing, a thermocouple positioned to monitor a temperature in the housing, and an electronic device. The housing includes an array of permanent magnets and a RF coil assembly. The method includes receiving, by a primary control circuit, a user input to initiate a RF scan, wherein the primary control circuit is in signal communication with a safety control circuit, transmitting, from the primary control circuit, a temperature signal indicative of the temperature detected by the thermocouple to the safety control circuit, and receiving, by the safety control circuit, a status signal indicative of an operational parameter from the electronic device. The method includes transmitting, by the safety control circuit, to an interface, an electronic notification based on a condition selected from a group consisting of the operational parameter being outside a predefined range of values and the temperature being outside a predefined range of temperatures. The method - 1 - 318293876.1Attorney Docket No.230094PCT further includes transmitting, by the safety control circuit, a stop scan signal to the primary control circuit based on the condition.

[0004] In yet another general aspect, the present disclosure describes a portable magnetic resonance (MR) imaging system, including a housing. The housing including an array of magnets positioned to project a low-field strength magnetic field into a region of interest, a radio frequency (RF) coil assembly configured to selectively excite magnetization in the region of interest, and a RF power amplifier in signal communication with the RF coil assembly. The RF power amplifier is configurable from a default configuration to an enabled configuration. In the enabled configuration the RF power amplifier amplifies an output from the RF coil assembly. In the default configuration the RF power amplifier does not modify the output from the RF coil assembly. The portable MR imaging system further includes a primary control circuit in signal communication with the RF coil assembly, wherein the primary control circuit is to receive an initiate scan signal indicative of a user input to initiate a MR scan. The portable MR imaging system further includes a safety control circuit in signal communication with the RF power amplifier and the primary control circuit. The safety control circuit is to receive, from the primary control circuit, a scanning status signal, and transmit, to the RF power amplifier, an enabling signal to configure the RF power amplifier in the enabled configuration throughout a scan duration based on the scanning status signal.

[0005] In yet another general aspect, the present disclosure describes a method of operating a portable MR imaging system including an array of permanent magnets, a RF coil assembly, and a RF power amplifier in signal communication with the RF coil assembly. The RF power amplifier is configurable in a default configuration and an enabled configuration. In the default configuration the RF power amplifier does not modify the RF signal of the RF coil assembly. In the enabled configuration the RF power amplifier modifies the RF signal of the RF coil assembly. The method including receiving, by a primary control circuit, a user input to initiate a RF scan, wherein the primary control circuit is in signal communication with a safety control circuit, transmitting, by the primary control circuit, a pulse frequency sequence to the RF coil assembly for a scan duration, and transmitting, by the primary control circuit, a scanning status signal to the safety control circuit. The method further includes transmitting, by the safety control circuit, an enabling signal to the RF power amplifier based on the scanning status signal, upon completion of the RF scan, transmitting, by the primary control circuit, a termination signal to the safety control circuit, receiving, by the safety control circuit, the termination signal, and transmitting, by the safety control circuit, a disabling signal to the RF power amplifier based on the termination signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The various aspects described herein, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings as follows.

[0007] FIG.1 depicts components of a MRI scanning system including a dome-shaped housing for a magnetic array, the dome-shaped housing surrounding a region of interest therein and further depicting the dome-shaped housing positioned to receive at least a portion of the head of a patient 318293876.1Attorney Docket No.230094PCT reclined on the table into the region of interest, in accordance with at least one aspect of the present disclosure.

[0008] FIG.2 is a perspective view of an alternative dome-shaped housing for a magnetic array for use with the MRI scanning system of FIG.1, wherein access apertures are defined in the dome- shaped housing, in accordance with at least one aspect of the present disclosure.

[0009] FIG.3 is a perspective view of an alternative dome-shaped housing for a magnetic array for use with the MRI scanning system of FIG.1, wherein access apertures and an adjustable gap is defined in the dome-shaped housing, in accordance with at least one aspect of the present disclosure.

[0010] FIG.4 depicts a dome-shaped housing for use with a MRI scanning system having an access aperture in the form of a centrally-defined hole, in accordance with at least one aspect of the present disclosure.

[0011] FIG.5 is a cross-sectional view of the dome-shaped housing of FIG.4, in accordance with at least one aspect of the present disclosure.

[0012] FIG.6 depicts a control schematic for a MRI system, in accordance with at least one aspect of the present disclosure.

[0013] FIG.7 is a flowchart describing a method for obtaining imaging data from an MRI system, in accordance with at least one aspect of the present disclosure.

[0014] FIG.8 depicts a MRI scanning system and a robotic system, in accordance with at least one aspect of the present disclosure.

[0015] FIG.9 illustrates an example MRI control schematic, in accordance with at least one aspect of the present disclosure.

[0016] FIG.10 illustrates an example method that can be executed by a control circuit of an MRI system to perform MRI scans, in accordance with at least one aspect of the present disclosure.

[0017] FIG.11 illustrates an example method that can be executed by a control circuit of an MRI system to perform MRI scans, in accordance with at least one aspect of the present disclosure.

[0018] FIGS.12A and 12B illustrate an example display that can be coupled to the interrupt control circuit, in accordance with at least one aspect of the present disclosure.

[0019] FIG.12C is an example plot of the temperature of the MRI system during the detection of an over temperature condition, in accordance with at least one aspect of the present disclosure.

[0020] FIG.13 illustrates two example series of LED lights of the MRI system providing a user with input regarding the operation of the MRI system during normal operation, in accordance with at least one aspect of the present disclosure.

[0021] FIG.14 illustrates the two example series of LED lights of the MRI scanner providing a user with input regarding the operation of the MRI scanner during an example fault condition being detected, in accordance with at least one aspect of the present disclosure.

[0022] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate various disclosed embodiments, is one form, and such exemplifications are not to be construed as limiting the scope thereof in any manner. 318293876.1Attorney Docket No.230094PCT DETAILED DESCRIPTION

[0023] Applicant of the present application also owns U.S. Patent Application Publication No. 2022 / 0354378, titled NEURAL INTERVENTIONAL MAGNETIC RESONANCE IMAGING APPARATUS, filed May 5, 2022, which is incorporated by reference herein in its entirety. Applicant of the present application also owns the PCT Patent Application titled, SCAN-BASED ACTIVATION OF MRI SYSTEM AMPLIFIERS, corresponding to Attorney Docket No.230098PCT, filed on even date herewith.

[0024] Before explaining various aspects of interventional magnetic resonance imaging devices in detail, it should be noted that the illustrative examples are not limited in application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. The illustrative examples may be implemented or incorporated in other aspects, variations and modifications, and may be practiced or carried out in various ways. Further, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative examples for the convenience of the reader and are not for the purpose of limitation thereof. Also, it will be appreciated that one or more of the following-described aspects, expressions of aspects, and / or examples, can be combined with any one or more of the other following-described aspects, expressions of aspects and / or examples.

[0025] Various aspects are directed to neural interventional magnetic resonance imaging (MRI) devices that allows for the integration of surgical intervention and guidance with an MRI. This includes granting physical access to the area around the patient as well as access to the patient’s head with one or more access apertures. In addition, the neural interventional MRI device may allow for the usage of robotic guidance tools and / or traditional surgical implements. In various instances, a neural interventional MRI can be used intraoperatively to obtain scans of a patient’s head and / or brain during a surgical intervention, such as a surgical procedure like a brain biopsy or neurosurgery.

[0026] FIG.1 depicts a MRI scanning system 100 that includes a dome-shaped housing 102 configured to receive a patient’s head. The dome-shaped housing 102 can further include at least one access aperture configured to allow access to the patient’s head to enable a neural intervention. A space within the dome-shaped housing 102 forms the region of interest for the MRI scanning system 100. Target tissue in the region of interest is subjected to magnetization fields / pulses, as further described herein, to obtain imaging data representative of the target tissue.

[0027] For example, a patient can be positioned such that his / her head is positioned within the region of interest within the dome-shaped housing 102. The brain can be positioned entirely within the dome-shaped housing 102. In such instances, to facilitate intracranial interventions (e.g. neurosurgery) in concert with MR imaging, the dome-shaped housing 102 can include one or more apertures that provide access to the brain. Apertures can be spaced apart around the perimeter of the dome-shaped housing.

[0028] The MRI scanning system 100 can include an auxiliary cart (see, e.g. auxiliary cart 530 in FIG.6) that houses certain conventional MRI electrical and electronic components, such as a computer, programmable logic controller, power distribution unit, and amplifiers, for example. The MRI scanning system 100 can also include a magnet cart that holds the dome-shaped housing 102, 318293876.1Attorney Docket No.230094PCT gradient coil(s), and / or a transmission coil, as further described herein. Additionally, the magnet cart can be attached to a receive coil in various instances. Referring primarily to FIG.1, the dome-shaped housing 102 can further include RF transmission coils, gradient coils 104 (depicted on the exterior thereof), and shim magnets 106 (depicted on the interior thereof). Alternative configurations for the gradient coil(s) 104 and / or shim magnets 106 are also contemplated. In various instances, the shim magnets 106 can be adjustably positioned in a shim tray within the dome-shaped housing 102, which can allow a technician to granularly configure the magnetic flux density of the dome-shaped housing 102.

[0029] Various structural housings for receiving the patient’s head and enabling neural interventions can be utilized with a MRI scanning system, such as the MRI scanning system 100. In one aspect, the MRI scanning system 100 may be outfitted with an alternative housing, such as a dome-shaped housing 202 (FIG.2) or a two-part housing 302 (FIG.3) configured to form a dome-shape. The dome-shaped housing 202 defines a plurality of access apertures 203; the two-part housing 302 also defines a plurality of access apertures 303 and further includes an adjustable gap 305 between the two parts of the housing.

[0030] In various instances, the housings 202 and 302 can include a bonding agent 308, such as an epoxy resin, for example, that holds a plurality of magnetic elements 310 in fixed positions. The plurality of magnetic elements 310 can be bonded to a structural housing 312, such as a plastic substrate, for example. In various aspects, the bonding agent 308 and structural housing 312 may be non-conductive or diamagnetic materials. Referring primarily to FIG.3, the two-part housing 302 comprises two structural housings 312. In various aspect, a structural housing for receiving the patient’s head can be formed from more than two sub-parts. The access apertures 303 in the structural housing 312 provide a passage directly to the patient’s head and are not obstructed by the structural housing 312, bonding agent 308, or magnetic elements 310. The access apertures 303 can be positioned in an open space of the housing 302, for example.

[0031] There are many possible configurations of neural interventional MRI devices that can achieve improved access for surgical intervention. Many configurations build upon two main designs, commonly known as the Halbach cylinder and the Halbach dome described in the following article: Cooley et al. (e.g. Cooley, C. Z., Haskell, M. W., Cauley, S. F., Sappo, C., Lapierre, C. D., Ha, C. G., Stockmann, J. P., & Wald, L. L. (2018). Design of sparse Halbach magnet arrays for portable MRI using a genetic algorithm. IEEE transactions on magnetics, 54(1), 5100112. The article “Design of sparse Halbach magnet arrays for portable MRI using a genetic algorithm” by Cooley et al., published in IEEE transactions on magnetics, 54(1), 5100112 in 2018, is incorporated by reference herein in its entirety.

[0032] In various instances, a dome-shaped housing for an MRI scanning system, such as the system 100, for example, can include a Halbach dome defining a dome shape and configured based on several factors including main magnetic field B0strength, field size, field homogeneity, device size, device weight, and access to the patient for neural intervention. In various aspects, the Halbach dome comprises an exterior radius and interior radius at the base of the dome. The Halbach dome may comprise an elongated cylindrical portion that extends from the base of the dome. In one aspect, 318293876.1Attorney Docket No.230094PCT the elongated cylindrical portion comprises the same exterior radius and interior radius as the base of the dome and continues from the base of the dome at a predetermined length, at a constant radius. In another aspect, the elongated cylindrical portion comprises a different exterior radius and interior radius than the base of the dome (see e.g. FIGS.2 and 3). In such instances, the different exterior radius and interior radius of the elongated cylindrical portion can merge with the base radii in a transitional region.

[0033] FIG.4 illustrates an exemplary Halbach dome 400 for an MRI scanning system, such as the system 100, for example, which defines an access aperture in the form of a hole or access aperture 403, where the dome 400 is configured to receive a head and brain B of the patient P within the region of interest therein, and the access aperture 403 is configured to allow access to the patient P to enable neural intervention with a medical instrument and / or robotically-controlled surgical tool, in accordance with at least one aspect of the present disclosure. The Halbach dome 400 can be built with a single access aperture 403 at the top side 418 of the dome 400, which allows for access to the top of the skull while minimizing the impact to the magnetic field. Additionally or alternatively, the dome 300 can be configured with multiple access apertures around the structure 416 of the dome 400, as shown in FIGS.2 and 3.

[0034] The diameter Dholeof the access aperture 403 may be small (e.g. about 2.54 cm) or very large (substantially the exterior rext diameter of the dome 400). As the access aperture 403 becomes larger, the dome 400 begins to resemble a Halbach cylinder, for example. The access aperture 403 is not limited to being at the apex of the dome 400. The access aperture 403 can be placed anywhere on the surface or structure 416 of the dome 400. In various instances, the entire dome 400 can be rotated so that the access aperture 403 can be co-located with a desired physical location on the patient P.

[0035] FIG.5 depicts relative dimensions of the Halbach dome 400, including a diameter Dholeof the access aperture 403, a length L of the dome 400, and an exterior radius rextand an interior radius rinof the dome 400. The Halbach dome 400 comprises a plurality of magnetic elements that are configured in a Halbach array and make up a magnetic assembly. The plurality of magnetic elements may be enclosed by the exterior radius rextand interior radius rinin the structure 416 or housing thereof. In one aspect, example dimensions may be defined as: rin= 19.3 cm; rext= 23.6 cm; L = 38.7 cm; and 2.54 cm D < 19.3 cm.

[0036] Based on the above example dimensions, a Halbach dome 400 with an access aperture 403 may be configured with a magnetic flux density B0 of around 72 mT, and an overall mass of around 35 kg. It will be appreciated that the dimensions may be selected based on particular applications to achieve a desired magnetic flux density B0, total weight of the Halbach dome 400 and / or magnet cart, and geometry of the neural intervention access aperture 403.

[0037] In various aspects, the Halbach dome 400 may be configured to define multiple access apertures 403 placed around the structure 416 of the dome 400. These multiple access apertures 403 may be configured to allow for access to the patient’s head and brain B using tools (e.g., surgical tools) and / or a surgical robot. 318293876.1Attorney Docket No.230094PCT

[0038] In various aspects, the access aperture 403 may be adjustable. The adjustable configuration may provide the ability for the access aperture 403 to be adjusted using either a motor, mechanical assist, or a hand powered system with a mechanical iris configuration, for example, to adjust the diameter Dholeof the access aperture 403. This would allow for configuration of the dome without an access aperture 403, conducting an imaging scan, and then adjusting the configuration of the dome 400 and mechanical iris thereof to include the access aperture 403 and, thus, to enable a surgical intervention therethrough.

[0039] Halbach domes and magnetic arrays thereof for facilitating neural interventions are further described in International Patent Application No. PCT / US2022 / 72143, titled NEURAL INTERVENTIONAL MAGNETIC RESONANCE IMAGING APPARATUS, filed May 5, 2022, which is incorporated by reference herein in its entirety.

[0040] Referring now to FIG.6, a schematic for an MRI system 500 is shown. The MRI scanning system 100 (FIG.1) and the various dome-shaped housings and magnetic arrays therefor, which are further described herein, for example, can be incorporated into the MRI system 500, for example. The MRI system 500 includes a housing 502, which can be similar in many aspects to the dome- shaped housings 102 (FIG.1), 202 (FIG.2), and / or 302 (FIG.3), for example. The housing 502 is dome-shaped and configured to form a region of interest, or field of view, 552 therein. For example, the housing 502 can be configured to receive a patient’s head in various aspects of the present disclosure.

[0041] The housing 502 includes a magnet assembly 548 having a plurality of magnets arranged therein (e.g. a Halbach array of magnets). In various aspect, the main magnetic field B0, generated by the magnetic assembly 548, extends into the field of view 552, which contains an object (e.g. the head of a patient) that is being imaged by the MRI system 500.

[0042] The MRI system 500 also includes RF transmit / receive coils 550. The RF transmit / receive coils 550 are combined into integrated transmission-reception (Tx / Rx) coils. In other instances, the RF transmission coil can be separate from the RF reception coil. For example, the RF transmission coil(s) can be incorporated into the housing 502 and the RF reception coil(s) can be positioned within the housing 502 to obtain imaging data.

[0043] The housing 502 also includes one or more gradient coils 504, which are configured to generate gradient fields to facilitate imaging of the object in the field of view 552 generated by the magnet assembly 548, e.g., enclosed by the dome-shaped housing and dome-shaped array of magnetic elements therein. Shim trays adapted to receive shim magnets 506 can also be incorporated into the housing 502.

[0044] During the imaging process, the main magnetic field B0extends into the field of view 552. The direction of the effective magnetic field (B1) changes in response to the RF pulses and associated electromagnetic fields transmitted by the RF transmit / receive coils 550. For example, the RF transmit / receive coils 550 may be configured to selectively transmit RF signals or pulses to an object in the field of view 552, e.g. tissue of a patient’s brain. These RF pulses may alter the effective magnetic field experienced by the spins in the sample tissue. 318293876.1Attorney Docket No.230094PCT

[0045] The housing 502 is in signal communication with an auxiliary cart 530, which is configured to provide power to the housing 502 and send / receive control signals to / from the housing 502. The auxiliary cart 530 includes a power distribution unit 532, a computer 542, a spectrometer 544, a transmit / receive switch 545, an RF power amplifier 546, and gradient amplifiers 558. In various instances, the housing 502 can be in signal communication with multiple auxiliary carts and each cart can support one or more of the power distribution unit 532, the computer 542, the spectrometer 544, the transmit / receive switch 545, the RF power amplifier 546, and / or the gradient amplifiers 558.

[0046] The computer 542 is in signal communication with a spectrometer 544 and is configured to send and receive signals between the computer 542 and the spectrometer 544. When the object in the field of view 552 is excited with RF pulses from the RF transmit / receive coils 550, the precession of the object results in an induced electric current, or MR current, which is detected by the RF transmit / receive coils 550 and sent to the RF preamplifier 546. The RF preamplifier 546 is configured to boost or amplify the excitation data signals and send them to the spectrometer 544. The spectrometer 544 is configured to send the excitation data to the computer 542 for storage, analysis, and image construction. The computer 542 is configured to combine multiple stored excitation data signals to create an image, for example. In various instances, the computer 542 is in signal communication with at least one database 562 that stores reconstruction algorithms 564 and / or pulse sequences 566. The computer 542 is configured to utilize the reconstruction algorithms to generate an MR image 568.

[0047] From the spectrometer 544, signals can also be relayed to the RF transmit / receive coils 550 in the housing 502 via an RF power amplifier 546 and the transmit / receive switch 545 positioned between the spectrometer 544 and the RF power amplifier 546. From the spectrometer 544, signals can also be relayed to the gradient coils 504 in the housing 502 via a gradient power amplifier 558. For example, the RF power amplifier 546 is configured to amplify the signal and send it to RF transmission coils 560, and the gradient power amplifier 558 is configured to amplify the gradient coil signal and send it to the gradient coils 560.

[0048] In various instances, the MRI system 500 can include noise cancellation coils 554. For example, the auxiliary cart 530 and / or computer 542 can be in signal communication with noise cancellation coils 554. In other instances, the noise cancellation coils 554 can be optional. For example, certain MRI systems disclosed herein may not include supplemental / auxiliary RF coils for detecting and canceling electromagnetic interference, i.e. noise.

[0049] A flowchart depicting a process 570 for obtaining an MRI image is shown in FIG.7. The flowchart can be implemented by the MRI system 500, for example. In various instances, at block 572, the target subject (e.g. a portion of a patient’s anatomy), is positioned in a main magnetic field B0 in an interest of region (e.g. region of interest 552), such as within the dome-shaped housing of the various MRI scanners further described herein (e.g. magnet assembly 548). The main magnetic field B0is configured to magnetically polarize the hydrogen protons (1H-protons) of the target subject (e.g. all organs and tissues) and is known as the net longitudinal magnetization M0. It is proportional to the proton density (PD) of the tissue and develops exponentially in time with a time constant known as the longitudinal relaxation time T1 of the tissue. T1 values of individual tissues depend on a number 318293876.1Attorney Docket No.230094PCT of factors including their microscopic structure, on the water and / or lipid content, and the strength of the polarizing magnetic field, for example. For these reasons, the T1 value of a given tissue sample is dependent on age and state of health.

[0050] At block 574, a time varying oscillatory magnetic field B1, i.e. an excitation pulse, is applied to the magnetically polarized target subject with a RF coil (e.g. RF transmit / receive coil 550). The carrier frequency of the pulsed B1 field is set to the resonance frequency of the 1H-proton, which causes the longitudinal magnetization to flip away from its equilibrium longitudinal direction resulting in a rotated magnetization vector, which in general can have transverse as well as longitudinal magnetization components, depending on the flip angle used. Common B1 pulses include an inversion pulse, or a 180-degree pulse, and a 90-degree pulse. A 180-degree pulse reverses the direction of the 1H- proton's magnetization in the longitudinal axis. A 90-degree pulse rotates the 1H-proton's magnetization by 90 degrees so that the magnetization is in the transverse plane. The MR signals are proportional to the transverse components of the magnetization and are time varying electrical currents that are detected with suitable RF coils. These MR signals decay exponentially in time with a time constant known as the transverse relaxation time T2, which is also dependent on the microscopic tissue structure, water / lipid content, and the strength of the magnetic field used, for example.

[0051] At block 576, the MR signals are spatially encoded by exposing the target subject to additional magnetic fields generated by gradient coils (e.g. gradient coils 560), which are known as the gradient fields. The gradient fields, which vary linearly in space, are applied for short periods of time in pulsed form and with spatial variations in each direction. The net result is the generation of a plurality of spatially encoded MR signals, which are detected at block 577, and which can be reconstructed to form MR images depicting slices of the examination subject. A RF reception coil (e.g. RF transmit / receive coil 550) can be configured to detect the spatially-encoded RF signals. Slices may be oriented in the transverse, sagittal, coronal, or any oblique plane.

[0052] At block 578, the spatially encoded signals of each slice of the scanned region are digitized and spatially decoded mathematically with a computer reconstruction program (e.g. by computer 542) in order to generate images depicting the internal anatomy of the examination subject. In various instances, the reconstruction program can utilize an (inverse) Fourier transform to back-transforms the spatially-encoded data (k-space data) into geometrically decoded data.

[0053] FIG.8 depicts a graphical illustration of a robotic system 680 that may be used for neural intervention with an MRI scanning system 600. The robotic system 680 includes a computer system 696 and a surgical robot 682. The MRI scanning system 600 can be similar to the MRI system 500 and can include the dome-shaped housing and magnetic arrays having access apertures, as further described herein. For example, the MRI system 500 can include one or more access apertures defined in a Halbach array of magnets in the permanent magnet assembly to provide access to one or more anatomical parts of a patient being imaged during a medical procedure. In various instances, a robotic arm and / or tool of the surgical robot 682 is configured to extend through an access aperture in the permanent magnet assembly to reach a patient or target site. Each access aperture can provide 318293876.1Attorney Docket No.230094PCT access to the patient and / or surgical site. For example, in instances of multiple access apertures, the multiple access apertures can allow access from different directions and / or proximal locations.

[0054] In accordance with various embodiments, the robotic system 680 is configured to be placed outside the MRI system 600. As shown in FIG.8, the robotic system 680 can include a robotic arm 684 that is configured for movements with one or more degrees of freedom. In accordance with various embodiments, the robotic arm 684 includes one or more mechanical arm portions, including a hollow shaft 686 and an end effector 688. The hollow shaft 686 and end effector 688 are configured to be moved, rotated, and / or swiveled through various ranges of motion via one or more motion controllers 690. The double-headed curved arrows in FIG.8 signify exemplary rotational motions produced by the motion controllers 690 at the various joints in the robotic arm 684.

[0055] In accordance with various embodiments, the robotic arm 684 of the robotic system 682 is configured for accessing various anatomical parts of interest through or around the MRI scanning system 600. In accordance with various embodiments, the access aperture is designed to account for the size of the robotic arm 684. For example, the access aperture defines a circumference that is configured to accommodate the robotic arm 684, the hollow shaft 686, and the end effector 688 therethrough. In various instances, the robotic arm 684 is configured for accessing various anatomical parts of the patient from around a side of the magnetic imaging apparatus 600. The hollow shaft 686 and / or end effector 688 can be adapted to receive a robotic tool 692, such as a biopsy needle having a cutting edge 694 for collecting a biopsy sample from a patient, for example.

[0056] The reader will appreciate that the robotic system 682 can be used in combination with various dome-shaped and / or cylindrical magnetic housings further described herein. Moreover, the robotic system 682 and robotic tool 692 in FIG.8 are exemplary. Alternative robotic systems can be utilized in connection with the various MRI systems disclosed herein. Moreover, handheld surgical instruments and / or additional imaging devices (e.g. an endoscope) and / or systems can also be utilized in connection with the various MRI systems disclosed herein.

[0057] In various aspects of the present disclosure, the MRI systems described herein can comprise low field MRI (LF-MRI) systems. In such instances, the main magnetic field B0 generated by the permanent magnet assembly can be between 0.1 T and 1.0 T, for example. In other instances, the MRI systems described herein can comprise ultra-low field MRI (ULF-MRI) systems. In such instances, the main magnetic field B0 generated by the permanent magnet assembly can be between 0.03 T and 0.1 T, for example.

[0058] Higher magnetic fields, such as magnetic fields above 1.0 T, for example, can preclude the use of certain electrical and mechanical components in the vicinity of the MRI scanner. For example, the existence of surgical instruments and / or surgical robot components comprising metal, specially ferrous metals, can be dangerous in the vicinity of higher magnetic fields because such tools can be drawn toward the source of magnetization. Moreover, higher magnetic fields often require specifically-designed rooms with additional precautions and shielding to limit magnetic interference. Despite the limitations on high field MRI systems, low field and ultra-low field MRI systems present various challenges to the acquisition of high quality images with sufficient resolution for achieving the desired imaging objectives. 318293876.1Attorney Docket No.230094PCT

[0059] LF- and ULF-MRI systems generally define an overall magnetic field homogeneity that is relatively poor in comparison to higher field MRI systems. For example, a dome-shaped housing for an array of magnets, as further described herein, can comprise a Halbach array of permanent magnets, which generate a magnetic field B0having a homogeneity between 1,000 ppm and 10,000 ppm in the region of interest in various aspects of the present disclosure.

[0060] Safety of the patient and MRI operators is an important consideration. If a MRI scanner malfunctions or another issue is undetected, safety may be compromised. Monitoring system-wide feedback from the MRI scanner (e.g. temperature, operating parameters, etc.) can improve patient safety and image quality. For example, continuously monitoring the status of internal subsystems of the MRI scanner can promptly determine if any fault conditions occur.

[0061] To continuously monitor an MRI system, an MRI scanner (e.g. MRI system 100, MRI system 500, or MRI scanning system 600) can by communicably coupled to a safety control circuit (e.g. a programmable logic controller), which monitors parameters of the MRI scanner (e.g. the temperature of the MRI scanner and / or the status of one or more subsystems in the MRI). The safety control circuit can further be configured to automatically disable or power-down the MRI scanner or one or more subsystems thereof. For example, if the temperature of the MRI scanner exceeds a predetermined threshold and / or a particular status is detected, the safety control circuit can disable or power-down the MRI scanner or a subsystem thereof. In various instances, the MRI scanner can be designed so that the power amplifiers of the MRI scanner are only enabled during an active scan, i.e. based on a determination that the scan is active or in progress. In such instances, MRI downtime is controlled while maintaining a safe environment.

[0062] MRI scanners generally require a high voltage and current to operate properly. Specifically, the power amplifiers can require a high voltage and current. Disabling the power amplifiers in certain circumstances can limit or avoid exposures to the high voltages and currents and, in certain instances, may improve the safety of the MRI system. For example, when the MRI scanner is not actively performing an MRI scan, the scanner can be moved around (e.g. wheeled around on casters and / or a cart) without posing a risk of exposing the operator and / or patient to the high voltages and current. A safety control circuit can continuously monitor conditions and statuses of the MRI scanner and, moreover, can automatically disable and depower the MRI scanner if a fault condition is detected, for example.

[0063] In at least one aspect, the MRI system 100, MRI system 500, and MRI scanning system 600 are portable MRI scanners. These portable MRI scanner can be compact, cryogen-free, and used in various standard and non-standard clinical environments. As illustrated in FIG.1, the portable MRI scanner 100 can be used to obtain MR images of a patient’s head. The head-optimized design of the portable MRI scanner maintains a close proximity between the patient’s head and the MRI scanner. Frequent temperature feedback and equipment monitoring with an immediate response can improve patient safety, for example.

[0064] FIG.9 illustrates an example MRI control schematic 700, in accordance with at least one aspect of the present disclosure. The MRI control schematic 700 can be incorporated into the various MRI system disclosed herein, including systems 100, 500, and 600, for example. Communication - 11 - 318293876.1Attorney Docket No.230094PCT paths are denoted with solid arrows and power dispersing is denoted with dashed arrows in FIG.9. The MRI control schematic 700 includes a primary control circuit 710, a safety control circuit 720, an interrupt control circuit 730, a power supply 740, a power distribution unit 750, one or more amplifiers 760 (e.g. gradient power amplifiers and RF power amplifiers), a spectrometer 770, and one or more thermocouples 780 attached to the magnets and / or gradient coils. The safety control circuit 720 continuously monitors the condition and status of the MRI scanner and can automatically disable or depower the MRI scanner if a fault condition is detected.

[0065] The primary control circuit 710 is communicably coupled to the spectrometer 770, one or more thermocouples 780, the safety control circuit 720, and an interface 790. In at least one aspect, the safety control circuit 720 operates independently of the primary control circuit 710. In at least one aspect, the interface 790 transmits user inputs to the primary control circuit 710 and receives MRI data to be displayed to the user. During an MRI scan, the spectrometer 770 transmits data indicative of an MRI image to the primary control circuit 710. Each thermocouple 880 continuously transmits temperature data indicative of the temperature detected at the location of the thermocouple 880 to the primary control circuit 710. The safety control circuit 720 transmits data indicative of the safety status of the MRI system to the primary control circuit 710. The primary control circuit 710 transmits data indicative of a scanning status to the safety control circuit 720. In an alternative aspect, during an MRI scan, the primary control circuit 710 transmits an RF pulse sequence directly to the RF power amplifiers 760.

[0066] A thermocouple 880 can be positioned on any element of the MRI system to provide the primary control circuit 710 with a temperature at the location of the thermocouple 880. For example, one or more thermocouples can be positioned on each gradient coil (e.g. gradient coils 104, gradient coils 504, or gradient coils 560) in the MRI scanner to provide the primary control circuit 710 with a temperature of each gradient coil. As another example, one or more thermocouples can be positioned on magnets (e.g. shim magnets 106, magnetic elements 310, or magnet assembly 548) in the MRI scanner to provide the primary control circuit 710 with a temperature of the magnets. As yet another example, one or more thermocouples can be positioned in the housing (e.g. dome-shaped housing 102, dome-shaped housing 202, two-part housing 302, or housing 502) of the MRI scanner to provide the primary control circuit 710 with a temperature of one or more components or electronic devices in the MRI scanner. Thermocouples can be embedded and positioned throughout the system, for example. In at least one aspect, the thermocouples are Pico Technology type-K thermocouple sensors.

[0067] The primary control circuit 710 transmits the temperature data to the safety control circuit 720. The safety control circuit 720 monitors the temperature and determines if the temperature is within normal operating conditions. For example, the safety control circuit 720 can compare a temperature to a predetermined temperature threshold and if the temperature exceeds the predetermined temperature range, then a temperature fault condition is detected. In at least one aspect, the predetermined temperature is 41°C. In other instances, the predetermined temperature can be greater than or less than 41°C. In an alternative aspect, the predetermined temperature is 35°C, for example. The predetermined temperature can depend on the type of scan, patient, location, and / or 318293876.1Attorney Docket No.230094PCT position of the thermocouple, for example. The predetermined temperature is programmable. By using multiple thermocouples, the safety control circuit 720 can monitor the temperature of different components or electronic devices of the MRI scanner (e.g. gradient coils, magnets, amplifiers, and etc.) to ensure the temperature of each component is within a temperature for expected operating behavior.

[0068] The interface 790 receives input from the user and displays or transmits MRI data for the user to view. In at least one aspect, the interface 790 comprises a graphical user interface. The graphical user interface can be placed on a display for a user to input data and the graphical user interface can display information to the user. For example, the graphical user interface can provide the user with a status of the MRI scanner and / or the status of subsystems of the MRI scanner. As another example, the graphical user interface can display a temperature of a component or electrical device of the MRI scanner. In at least one aspect, the interface 790 further includes a status indicator to provide the user with a status of the MRI scanner. For example, the MRI scanner can include a display to provide a status of the MRI scanner. In at least one aspect, the interface 790 includes a series of LED lights that provide a status of the MRI scanner. For example, the MRI scanner can include a first plurality of LED lights on an exterior of the housing to provide a brief status of the MRI scanner and a second plurality of lights on an interior surface of the housing to provide a detailed status of the MRI scanner for diagnostic purposes.

[0069] In at least one aspect, the primary control circuit 710 receives an input from a user to begin an MRI scan through the interface 790 and the primary control circuit 710 transmits information to be displayed to the user through the interface 790.

[0070] In at least one aspect, the safety control circuit 720 is a programmable logic controller. The safety control circuit 720 automates fail-safe control of the MRI scanner by real-time monitoring temperature as well as the status of internal subsystems of the MRI scanner. This process makes it easier to diagnose faults and quickly correct the MRI scanner to maintain safe operating behavior with the MRI scanner. In at least one aspect, the safety control circuit 720 implements fail-safe logic to minimize a users’ needed attention to MRI components and to prevent critical magnetic resonance hardware conditions such as overheating issues. In at least one aspect, the safety control circuit 720 can self-diagnose a fault condition and control the MRI scanner to disable a device due to the fault condition being detected.

[0071] The safety control circuit 720 is communicably coupled to the primary control circuit 710, the interrupt control circuit 730, the power distribution unit 750, and one or more amplifiers 760 (e.g. RF power amplifiers and / or gradient power amplifiers). In at least one aspect, the safety control circuit 720 transmits an enable or disable signal to the amplifiers 760 and receives an operational parameter signal from the amplifiers 760. The safety control circuit 720 transmits a power distribution signal to the power distribution unit 750. The power distribution signal informs the power distribution unit 750 to which of the electronic devices in the MRI scanner current or power should be supplied. The power distribution unit 750 supplies current to the different electronic devices (e.g. amplifiers) based on the power distribution signal. In at least one aspect, the power distribution unit 750 includes a relay for 318293876.1Attorney Docket No.230094PCT each electronic device being supplied power. The power distribution unit 750 can control each relay individually to either supply power or shut off power to an electronic device connected to the relay.

[0072] In at least one aspect, one of the amplifiers 760 is an RF power amplifier. The RF power amplifier is coupled to an RF coil to modify (e.g. amplify) a pulse sequence being transmitted to the RF coil. The RF power amplifier is configurable in a default configuration and an enabled configuration. In the enabled configuration, the RF power amplifier modifies an RF signal of the RF coil assembly. Stated another way, in the enabled configuration, the RF power amplifier produces an output based on an input. The RF power amplifier amplifies the RF signal of the RF coil assembly and outputs a high voltage and / or current. In the default configuration, the RF power amplifier does not modify the RF signal of the RF coil assembly. Stated another way, in the default configuration, no outputs will be produced by the RF power amplifier even with the presence of an input. The RF power amplifier is still powered on in the default configuration. The RF power amplifier does not output a signal in the default configuration and, as such, does not output a high voltage and / or current.

[0073] In at least one aspect, the RF power amplifier includes a switch. In the default configuration, the switch is open, thus, preventing any output from the RF power amplifier. In at least one aspect, the switch comprises a normally-open switch. In the enabled configuration, the switch is closed allowing an output from the RF power amplifier.

[0074] Each amplifier (or other electronic device) transmits operational parameters to the safety control circuit 720. In at least one aspect, the operational parameters include a voltage supplied to the electronic device, and a status of the electronic device. For example, the status of an amplifier could be indicative of the default configuration or the enabled configuration. In various aspects, the status is indicative of whether the electronic device is over-temperature or not, i.e. within a suitable temperature range. In other words, the operational parameter can be a DC signal identifying the temperature status of the amplifier. In at least one aspect, the RF power amplifier receives a disabling signal from the safety control circuit 720 to cause the RF power amplifier to transition from the enabled configuration to the default configuration. In at least one alternative aspect, the RF power amplifier receives an enabling signal from the safety control circuit 720 to cause the RF power amplifier to transition from the default configuration to the enabled configuration.

[0075] The interrupt control circuit 730 operates independently from the primary control circuit 710 or the safety control circuit 720. The interrupt control circuit 730 includes a switch 732. When the switch 732 is closed, power from the power supply 740 is supplied to the power distribution unit 750 and the power distribution unit 750 disperses power to at least the one or more amplifiers 760. In at least one aspect, the power distribution unit can dispense power to specific amplifiers 760 and withhold power to other amplifiers 760. When the switch 732 is opened, the power supply 740 is cut off from the power distribution unit 750 and, as such, power is not supplied to the one or more amplifiers 760. In at least one aspect, the interrupt control circuit 730 is a Brentek P8-WDR24 / PLC watchdog.

[0076] The safety control circuit 720 continuously (e.g. every 500 milliseconds) transmits a power enable signal to the interrupt control circuit 730. If the interrupt control circuit 730 does not receive a power enable signal within a predetermined time period (e.g. every 500 milliseconds), then the interrupt control circuit 730 opens the switch 732. If the interrupt control circuit 730 receives a power 318293876.1Attorney Docket No.230094PCT enable signal within the predetermined time period (e.g. every 500 milliseconds), then the interrupt control circuit 730 keeps the switch 732 closed or closes the switch 732 if it was previously open. In at least one aspect, this process allows the interrupt control circuit 730 to shut-down power to the amplifiers if something goes wrong and the safety control circuit 720 stops or is not able to transmit the power enable signal.

[0077] In at least one aspect, the power supply 740 supplies power to the primary control circuit 710, safety control circuit 720, and interrupt control circuit 730. As such, if the interrupt control circuit 730 opens the switch 732 and depowers the MRI scanner, the primary control circuit 710, safety control circuit 720, and interrupt control circuit 730 will remain powered by the power supply. This process depowers the potential high voltage and / or high current equipment and allows the primary control circuit 710, safety control circuit 720, and interrupt control circuit 730 to remain powered for diagnostics and troubleshooting of any issues.

[0078] In at least one aspect, the safety control circuit 720 continuously monitors the temperature of the thermocouples. If a temperature at a thermocouple exceeds a predetermined temperature threshold, then the safety control circuit 720 can stop transmitting the power enable signal to the interrupt control circuit 730, which causes the interrupt control circuit 730 to open the switch 732 depowering the MRI scanner. In at least one aspect, the switch 732 is opened when a temperature above a predetermined threshold is detected. For example, detection of a temperature above the predetermined threshold effects opening of the switch 732. In various instances, the switch 732 is only opened when a temperature outside a suitable operating temperature range is detected.

[0079] In at least one aspect, the safety control circuit 720 can monitor an operational parameter of an MRI subsystem (e.g. an operational parameter from an amplifier 760, a temperature from a thermocouple 780, or etc.). The safety control circuit 720 can determine if the operational parameter exceeds normal, or expected, operating behavior. In some aspects, the safety control circuit 720 can determine that a fault condition is met based on the operational parameter being outside normal operating behavior or an out-of-range condition (e.g. high temperature, high or low duty cycle, etc.). For example, the safety control circuit 720 can determine that the operational parameter is outside of a predetermined range or that the operational parameter has exceeded a predetermined threshold.

[0080] If the safety control circuit 720 detects a fault condition, then the safety control circuit 720 can perform one or more operations. The operations include stopping transmission of the power enable signal, transmitting an updated power distribution signal to the power distribution unit 750 causing the power distribution unit 750 to depower an electronic device, and / or transmitting a disable signal to an amplifier causing the amplifier to move from an enabled configuration to a disabled configuration. The operations performed by the safety control circuit 720 are based on the fault condition.

[0081] In some aspects, the safety control circuit 720 can perform operations to correct the fault condition and place the MRI scanner back in normal operating behavior. The safety control circuit 720 can evaluate an operational parameter by comparing the operational parameter to a predetermined threshold. The safety control circuit 720 can determine that the operational parameter is outside normal operating behavior based on the comparison (e.g. the operational parameter exceeding the predetermined threshold). The safety control circuit 720 can then characterize the operational 318293876.1Attorney Docket No.230094PCT parameter (or fault condition) as resettable or non-resettable. If the operational parameter is resettable, then the safety control circuit 720 can perform an operation to correct the operational parameter and place the MRI scanner back in normal operating behavior. If the operational parameter is non-resettable, then the safety control circuit 720 cannot perform an operation to correct the operational parameter. In such instances, outside maintenance of the MRI scanner may be required prior to resuming operations. The safety control circuit 720 can transmit an electronic notification to the primary control circuit 710 and display the electronic notification via the interface 790, where the electronic notification is indicative of the characterization of the operational parameter.

[0082] If the safety control circuit 720 characterizes the operational parameter (or fault condition) as resettable, then the safety control circuit 720 automatically resets the MRI scanner. The operation performed by the safety control circuit 720 to reset the MRI scanner can be different based on the operational parameter.

[0083] In at least one aspect, automatically resetting the MRI scanner includes powering down the MRI scanner by transmitting, from the safety control circuit 720, a power distribution signal to the power distribution unit 750. In this aspect, the power distribution signal causes the power distribution unit 750 to cut off power to the electronic devices being dispersed power. In an additional or alternative aspect, automatically resetting the MRI scanner includes powering down the MRI scanner by stopping the transmission of the power enable signal from the safety control circuit 720 to the interrupt control circuit 730. The MRI scanner can be powered down for a predetermined amount of time to reset the MRI scanner. For example, the MRI scanner can be powered down for a predetermined amount of time if an electronic component or subsystem overheats to allow the electronic component to cool. In at least one aspect, the safety control circuit 720 keeps the MRI scanner powered down until the temperature enters an acceptable range before the safety control circuit will restart the MRI scanner. In some aspects, the temperature needs to cool down to below 25°C, for example. Alternative temperature thresholds are contemplated.

[0084] In at least one aspect, automatically resetting the MRI scanner includes powering down or disabling an electronic device or subsystem of the MRI scanner. For example, the safety control circuit 720 can transmit a power distribution signal to the power distribution unit 750 to cause the power distribution unit 750 to stop dispensing power to the electronic device or subsystem. As another example, the safety control circuit 720 can transmit a disabling signal from the safety control circuit 720 to an amplifier 760 (e.g. an RF power amplifier) to cause the amplifier 760 to transition from the enabled configuration to the default configuration. The electronic device or subsystem can be powered down or disabled for a predetermined amount of time to reset the MRI scanner. For example, the electronic device or subsystem can be powered down or disabled for a predetermined amount of time if an electronic component or subsystem overheats to allow the electronic device or subsystem to cool. As another example, the electronic device or subsystem (e.g. an amplifier 760) can be placed in the default configuration (as discussed above) due to a duty cycle of the electronic device or subsystem being outside of a predetermined range of values. This process can be performed to allow the electronic device or subsystem to be troubleshot by a user or to allow the electronic device to cool and begin functioning within normal operating behavior. 318293876.1Attorney Docket No.230094PCT

[0085] The MRI system 100, MRI system 500, or MRI scanning system 600 can use the example MRI control schematic 700 for control of the MRI system to improve safety of operating the MRI system. For example, the computer 542 of MRI system 500 can operate multiple components of the MRI control schematic 700 or the primary control circuit 710 of the MRI control schematic 700 can be incorporated into the computer 542, for example.

[0086] FIG.10 illustrates an example method 800 that can be executed by a control circuit (e.g. safety control circuit 720) of an MRI system (e.g. MRI system 100, MRI system 500, or MRI scanning system 600) to perform MRI scans, in accordance with at least one aspect of the present disclosure. The method 800 begins with the control circuit determining 804 if an MRI scan is in progress. The control circuit can receive a signal indicative of the status of an MRI scan. For example, the primary control circuit 710 can receive an input from a user through the interface 790 to start an MRI scan, and the primary control circuit 710 can then transmit a scanning status signal to the safety control circuit 720, where the scanning status signal is indicative of an MRI scan being in progress. Once the MRI scan is completed, the primary control circuit 710 can transmit to the safety control circuit 710 a scanning status signal indicative of the MRI scan no longer being in progress. In at least one aspect, the current status of the scanning status signal can be used to indicate if an MRI scan is being performed or not.

[0087] If the control circuit determines that an MRI scan is not in progress, then the method 800 proceeds along the “no” branch. The method 800 further includes the control circuit disabling 814 the electronic devices (e.g. amplifiers 760) of the MRI scanner. For example, the safety control circuit 720 can transmit a disable signal to an amplifier 760 to cause the amplifier 760 to transition from the enabled configuration to the default configuration. Then, the method 800 proceeds to determine 804 if an MRI is in progress. This process keeps the electronic devices (e.g. amplifiers 760) of the MRI scanner disabled until an MRI is being scanned.

[0088] If the control circuit determines that an MRI scan is in progress, then the method 800 proceeds along the “yes” branch. The method 800 further includes enabling 806 the electronic devices (e.g. amplifiers 760) of the MRI scanner. For example, the safety control circuit 720 can transmit an enable signal to an amplifier 760 to cause the amplifier 760 to transition from the default configuration to the enabled configuration.

[0089] The method 800 includes the control circuit monitoring 808 for fault conditions (e.g. a temperature exceeding a predetermined threshold, or another operational parameter being outside a predetermined range). The method 800 includes the control circuit determining 810 if a fault condition is detected. If a fault condition is detected, then the method 800 proceeds along the “yes” branch. The method 800 further includes the control circuit disabling 814 the electronic devices (e.g. amplifiers 760) of the MRI scanner as discussed above. Then the method 800 proceeds to determine 804 if an MRI scan is in progress.

[0090] If a fault condition is not detected, then the method 800 proceeds along the “no” branch. The method 800 further includes the control circuit determining 812 if the MRI scan is still in progress. For example, the safety control circuit 710 can receive a scanning status signal indicative of the MRI scan 318293876.1Attorney Docket No.230094PCT being ongoing or not. In at least one aspect, the current status of a scanning status signal can be used to indicate if an MRI scan is being performed.

[0091] If the MRI scan is still in progress, then the method 800 proceeds along the “yes” branch and the control circuit monitors 808 for fault conditions as discussed above. If the MRI scan is no longer in progress, then the method 800 proceeds along the “no” branch and the control circuit disables 814 the electronic devices (e.g. amplifiers 760) of the MRI scanner, as discussed above. Then the method 800 proceeds to determine 804 if an MRI scan is in progress. As discussed above, the method 800 enables the electronic devices (e.g. amplifiers 760) of the MRI scanner during an MRI scan and disables the electronic devices (e.g. amplifiers 760) of the MRI scanner after the MRI scan is over. In at least one aspect, the MRI scan is over if a fault condition is met.

[0092] Referring to FIG.11, a method 900 includes additional example fault conditions that can be monitored in certain instances. The method 900 can be executed by a control circuit (e.g. safety control circuit 720) of an MRI system (e.g. MRI system 100, MRI system 500, or MRI scanning system 600) to perform MRI scans, in accordance with at least one aspect of the present disclosure. The method 900 begins with the control circuit powering 904 on all equipment (e.g. amplifiers 760, SDRs, and / or time and frequency distribution modules) of the MRI scanner. For example, the safety control circuit 720 can transmit a power distribution signal to the power distribution unit 750 causing the power distribution unit 750 to turn on relays to power the equipment (e.g. amplifiers 760) coupled to the relays. The equipment (e.g. amplifiers 760) begins in the default configuration upon powering on.

[0093] Similar to the method 800, the method 900 includes the control circuit determining 906 if an MRI scan is initiated. The control circuit can receive a signal indicative of the status of an MRI scan. For example, the primary control circuit 710 can receive an input from a user through the interface 790 to start an MRI scan, and the primary control circuit 710 can then transmit a scanning status signal to the safety control circuit 720, where the scanning status signal is indicative of an MRI scan being in progress. Once the MRI scan is completed, the primary control circuit 710 can transmit to the safety control circuit 710 a scanning status signal indicative of the MRI scan no longer being in progress. In at least one aspect, the current status of the scanning status signal can be used to indicate if an MRI scan is being performed.

[0094] If the control circuit determines that an MRI scan is not in progress, then the method 900 proceeds along the “no” branch. The method 900 further includes the control circuit disabling 908 the equipment (e.g. amplifiers 760) of the MRI scanner. For example, the safety control circuit 720 can transmit a disable signal to an amplifier 760 to cause the amplifier 760 to transition from the enabled configuration to the default configuration. In the default configuration, no outputs will be produced by the equipment even with the presence of an input. The equipment is still powered on in the default configuration. Then, the method 800 proceeds to determine 804 if an MRI is in progress. The foregoing process keeps the electronic devices (e.g. amplifiers 760) of the MRI scanner disabled until an MRI is being actively obtained by the scanner.

[0095] The method 900 further includes the control circuit determining 910 if a temperature from a thermocouple (e.g. thermocouple 780) is above a predetermined threshold. For example, the safety control circuit 720 constantly checks whether a temperature in the MRI scanner exceeds the 318293876.1Attorney Docket No.230094PCT predetermined threshold. If a temperature is above a predetermined threshold, the method 900 proceeds along the “yes” branch. The method 900 further includes the control circuit causing 938 the interrupt control circuit switch (e.g. switch 732) to be placed in the open position. For example, the safety control circuit 720 can stop transmitting the power enable signal to the interrupt control circuit 730, which causes the interrupt control circuit 730 to open the switch 732. As discussed above, the opening of the switch 732 powers down the equipment (e.g. amplifiers 760) by cutting off power to the power distribution unit.

[0096] If a temperature is not above the predetermined threshold (or otherwise outside the threshold range), the method 900 proceeds along the “no” branch. The method 900 further includes the control circuit placing 912 the system in an idle state. In at least one aspect, in the idle state, the control circuit is waiting for an input indicative of an MRI scan being initiated.

[0097] If the control circuit determines that an MRI scan is in progress, then the method 900 proceeds along the “yes” branch. The method 900 further includes the control circuit determining 914 if a fault condition is met for any equipment of the MRI scanner. For example, an electronic device (e.g. an amplifier 760) can transmit an operational parameter to the safety control circuit 720. Some non-limiting examples of operational parameters are device temperature, duty cycle, device status, etc. The safety control circuit 720 can compare the operational parameter to a predetermined threshold or a predetermined threshold range. A fault condition can be detected if the operation parameter exceeds the threshold or is outside of the predetermined threshold range. For example, a duty cycle above a predetermined duty cycle threshold can be a fault condition and a temperature above a predetermined temperature threshold can be another fault condition.

[0098] If a fault condition is detected, then the method 900 proceeds along the “yes” branch. The method 900 further includes the control circuit disabling 926 the equipment (e.g. amplifiers 760) of the MRI scanner, as discussed above in regard to method 800. For example, if a fault condition is met, then the equipment is disabled (e.g. the equipment is placed in the default configuration). If no fault conditions are detected, then the method 900 proceeds along the “no” branch. The method 900 further includes the control circuit enabling 916 all the equipment (e.g. amplifiers 760) of the MRI scanner. For example, the safety control circuit 720 can transmit an enable signal to an amplifier 760 to cause the amplifier 760 to transition from the default configuration to the enabled configuration.

[0099] The method 900 further includes the control circuit determining 918 if a fault condition is met for any equipment of the MRI scanner, as discussed above in regard to method 800. For example, the safety control circuit 720 can determine if a fault condition is met before enabling any equipment and after enabling the equipment. This process ensures that the equipment is working properly, (e.g. expected inputs result in expected outputs). If a fault condition is detected, then the method 900 proceeds along the “yes” branch. The method 900 further includes the control circuit disabling 926 the equipment (e.g. amplifiers 760) of the MRI scanner, as discussed above in regard to method 800. Once again if a fault condition is met, then the equipment is disabled (e.g. the equipment is placed in the default configuration).

[0100] Once the equipment is disabled, the method 900 further includes the control circuit notifying 928 a user of the fault condition. For example, the control circuit 720 can transmit to the primary 318293876.1Attorney Docket No.230094PCT control circuit 710 a status indication of the error or fault condition and the termination of the MRI scan before it had finished. The primary control circuit 710 can then notify the user of the error through a graphical user interface of the interface 790. In some aspects, the notification to the sure has details of the fault condition. In some alternative aspects, the user is only informed of the error and no details are disclosed to the user in the notification. Additionally, the method 900 further includes the control circuit stopping 930 the current MRI scan after detection of a fault condition and before the scan was completed.

[0101] The method 900 further includes the control circuit determining 932 that the equipment has been successfully disabled. For example, an electronic device (e.g. an amplifier 760) can transmit to the safety control circuit 720 a status signal indicative of the electronic device being in the default configuration (i.e. disabled) or the enabled configuration. If an electronic device is enabled, then the method 900 proceeds along the “no” branch. The method further includes the control circuit depowering 934 the electronic devices that were not disabled. For example, the safety control circuit 720 can transmit a power distribution signal to the power distribution unit 750, causing the power distribution unit 750 to shut off power to the desired electronic devices that did not become disabled. In at least one aspect, the power distribution unit 750 includes relays that are used to control the flow of power out of the power distribution unit 750. If all the electronic devices is disabled, then the method 900 proceeds along the “yes” branch.

[0102] The method 900 further includes the control circuit determining 940 if manual servicing of the scanner is required. For example, some fault conditions do not require external intervention or maintenance by technicians. For example, if the system can be be fixed with software and / or switching the power, manual service is not required. Otherwise, manual service may be required. The safety control circuit 720 can perform a self-analysis to determine if manual service is currently needed or if the MRI scanner can be brought back to normal operating behavior without manual servicing thereof. If manual service is required to repair or resolve errors, then the method proceeds along the “yes” branch. In such instances, the method 900 further includes the control circuit informing 944 the user that manual service is required by a trained technician. For example, the safety control circuit can transmit a safety status to the primary control circuit 710 and the notification of needed maintenance can be presented to the user through the graphical user interface of the interface 790. In at least one aspect, during manual servicing, the safety control circuit cycle ends and once the manual servicing is finished, a new safety control circuit cycle is started. If manual service is not required, the method 900 proceeds along the “no” branch and a self-reset process can be performed.

[0103] The method 900 can further includes the control circuit performing 942 a self-resetting process. For example, some fault conditions can be corrected by rebooting the MRI Scanner (e.g. rebooting the MRI scanner software) or shutting down the MRI scanner. The exact self-resetting process can be determined based on the fault condition. For example, in some aspects, a fault condition of over-heating can be resolved by powering down the electronic device or MRI scanner for a predetermined amount of time to allow the electronic device or MRI scanner to cool. Once the self- resetting process is performed, the method 900 proceeds to powering 904 on all the equipment and the method 900 cycles again. 318293876.1Attorney Docket No.230094PCT

[0104] If a self-resetting process is performed multiple times without removing the fault condition, then the control circuit determines that manual service is required. For example, the safety control circuit 720 can track the number of self-resetting processes performed and determine that manual service is required if a self-resetting process is performed a predetermined number of times without removing the fault condition. Additionally, if the control circuit keeps the MRI scanner powered down for a period of time exceeding a predetermined amount of time without removing the fault condition, then the control circuit determines that manual service is required. For example, the safety control circuit 720 can power down the MRI scanner to allow the MRI scanner to cool down to below a threshold value; however, if the MRI scanner does not cool down within a predetermined amount of time, then the safety control circuit 720 can determine that manual service is required.

[0105] If a fault condition is not detected, then the method 900 proceeds along the “no” branch connected to determining 918 if a fault condition is met for any equipment of the MRI scanner. The method 900 further includes the control circuit determining 920 if a temperature from a thermocouple (e.g. thermocouple 780) is above a predetermined threshold, as discussed above in regard to method 800. If a temperature is above a predetermined threshold, the method 900 proceeds along the “yes” branch. The method 900 further includes the control circuit causing 938 the interrupt control circuit switch (e.g. switch 732) to be placed in the open position, as discussed above in regard to method 800. The method 900 further includes the control circuit depowering 936 the MRI scanner. For example, when the interrupt control circuit switch (e.g. switch 732) is placed in the open position, power is no longer supplied through the power distribution unit 750 and the system is powered off. Additionally, the safety control circuit 720 can transmit a power distribution signal to the power distribution unit 750, causing the power distribution unit 750 to shut off power to all the electronic devices. The primary control circuit 710, the safety control circuit 720, and the interrupt control circuit 730 remain powered by the power supply 740, when the interrupt control circuit switch is be placed in the open position. Once the system is powered down, the method 900 further includes the control circuit determining 940 if manual servicing is required, as discussed above in regard to method 800.

[0106] If a temperature is not above the predetermined threshold, the method 900 proceeds along the “no” branch. The method 900 further includes the control circuit allowing 922 the MRI scanner to operate and perform the MRI scan. During an MRI scan the safety control circuit 720 continuously monitors the temperature and operational parameters to detect a fault condition if a temperature or operational parameter exceeds a predetermined threshold or predetermined threshold range, as discussed above.

[0107] The method 900 further includes the control circuit determining 924 that the MRI scan has been completed. For example, the primary control circuit 710 can transmit to the safety control circuit 720 a scanning status signal indicative of the MRI scan no longer being in progress. Once the MRI scan has completed, the method 900 proceeds to determining 906 if an MRI scan is initiated, as discussed above in regard to method 800.

[0108] In at least one aspect, the interrupt control circuit 730 is coupled to a display and the display can be used to inform a user if power is received by the interrupt control circuit 730 and if the interrupt control circuit 730 is outputting power. FIGS.12A and 12B illustrate an example display 1000 that can 318293876.1Attorney Docket No.230094PCT be coupled to the interrupt control circuit 730. The display 1000 has a power indicator 1010 and an output indicator 1020, wherein the dashed lines indicate an illuminated icon and the solid lines indicate a non-illuminated icon. FIG.12A illustrates the interrupt control circuit 730 receiving power and outputting power. FIG.12B illustrates the interrupt control circuit 730 receiving power and not outputting power.

[0109] FIG.12C is an example plot 1030 of the temperature of the MRI system during the detection of an over-temperature condition, in accordance with at least one aspect of the present disclosure. The plot 1030 illustrates a temperature line 1040 across time for an over-temperature condition. A predetermined temperature threshold of 35°C is shown by temperature threshold line 1070. As shown by the temperature line 1040, the temperature begins below the temperature threshold line 1070 with the MRI scanner in normal operation 1032. As time goes on the temperature increases until the temperature exceeds the temperature threshold line 1070 at time 5.6 minutes indicated by line 1050. The safety control circuit 720 detects the temperature above the predetermined temperature threshold at 5.6 minutes and the MRI scanner enters the over-temperature condition 1034. In at least one aspect, the safety control circuit 720 stopped transmitting the power enable signal to the interrupt control circuit 730 to cause the switch 732 to open powering down the system. The display 1000 illustrates that power is being output from the interrupt control circuit 730 (FIG.12B). The safety control circuit 720 caused the primary control circuit 710 to notify the user of the over-temperature condition through the interface 790 as discussed above. In at least one aspect, the safety control circuit 720 then performed a self-resetting process of shutting down the MRI scanner for a predetermined amount of time to allow the MRI scanner to cool. As shown by the temperature line 1040, the temperature cooled down to an acceptable range (e.g. below 25°C) and the MRI scanner entered normal operation 1036 at time 14 minutes indicated by line 1060. Once the temperature is within an acceptable range, the safety control circuit 720 can transmit a power enable signal to the interrupt control circuit 730 causing the switch 732 to move to the closed position. In such instance, the display 1000 illustrates that power is being output from the interrupt control circuit 730 (FIG.12A).

[0110] In at least one aspect, the interface 790 includes a series of LED lights that provide a status of the MRI scanner. FIG.13 illustrates two example series of LED lights 1200 and 1300 of the MRI scanner providing a user with information regarding the operation of the MRI scanner during normal operation, in accordance with at least one aspect of the present disclosure. FIG.14 illustrates the two example series of LED lights 1200 and 1300 of the MRI scanner providing a user with information regarding the operation of the MRI scanner during an example fault condition being detected, in accordance with at least one aspect of the present disclosure.

[0111] The series of LED lights 1200 can be positioned within the housing of the MRI scanner. The series of LED lights 1200 can include equipment disabled LED indicators 1110 (FIG.14), safety control circuit LED indicators 1120, an interrupt control circuit LED indicator 1130, equipment powered on LED indicators 1140, and fault indicators 1150 (FIG.14). The disabled LED indicators 1110 indicate electronic devices that have been disabled (e.g. placed in the default configuration). The safety control circuit LED indicators 1120 indicate the power amplifiers are operating properly based on the safety control circuit monitoring operating parameters (e.g. temperature, duty cycle, etc.) of the 318293876.1Attorney Docket No.230094PCT MRI scanner. The interrupt control circuit LED indicators 1130 indicate that the interrupt control circuit is operating properly. The equipment powered on LED indicators 1140 indicate the equipment that is receiving power. The fault indicators 1150 indicates that a fault is detected.

[0112] The series of LED lights 1300 can be positioned on an exterior surface of the MRI scanner. In some alternative aspects, the series of LED lights 1300 can be position on an internal surface of the MRI scanner. The series of LED lights 1300 can include a DC power indicator, an enable indicator, an RF power indicator, a DC error indicator, a mismatch indicator, an over-temperature indicator, an over-duty indicator, and a shutdown indicator. The RF power indicator indicates that the RF power amplifier is powered on. The mismatch indicator is based on the comparison of the impedance from the RF coil and RF power amplifier output to indicate if there is a mismatch. The DC power indicator indicates that power is being received by the RF power amplifier. The enable indicator indicates the MRI system is enabled and the interrupt control circuit switch is closed. The DC error indicator indicates an issue with the DC power for the RF power amplifier. The over-temp indicator indicates a temperature having exceeded a predetermined temperature threshold. The over duty indicator indicates that an electronic device has a duty cycle that has exceeded a predetermined duty cycle threshold. The shutdown indicator indicates that the MRI scanner has been disabled.

[0113] FIG.13 shows the series of LED lights 1200 and 1300 under normal operating condition. During normal operating conditions, the display 1000 (FIG.12A) indicates that the interrupt control circuit is receiving power and outputting power. FIG.14 shows the series of LED lights 1200 and 1300 when an over duty fault is detected by the safety control circuit 720. As shown by the indicators 1110, the electronic devices (e.g. amplifiers 760) are disabled (e.g. placed in the default configuration). The fault condition indicators 1150 are powered on for the LED lights 1200 and 1300. For example, the over duty indicator and shutdown indicator are powered on. These indicators inform a user that the over duty fault was detected and the electronic devices are disabled (i.e. shutdown). During the over duty fault condition, the display 1000 (FIG.12A) indicates that the interrupt control circuit is receiving power and outputting power.

[0114] During an over duty fault condition, the safety control circuit 720 disables the amplifiers 760. Stated another way, the safety control circuit 720 places the amplifiers 760 in the default configuration as discussed above. The safety control circuit 720 then notifies the user of the over-duty fault condition. In some aspects, the safety control circuit 720 does not provide details of the fault condition and only notifies the user of an error in the equipment. For example, the safety control circuit 720 can transmit a safety status to the primary control circuit 710 and the notification can be presented to the user through the graphical user interface of the interface 790 based on the safety status. The interrupt control circuit switch 732 remains closed during an over-duty fault condition. In some aspects, the over duty fault condition can be cleared by a reboot of the MRI scanner after confirming there is not a short in the circuit.

[0115] Examples

[0116] Various aspects of the subject matter described herein are set out in the following numbered examples. 318293876.1Attorney Docket No.230094PCT

[0117] Example 1 - A portable magnetic resonance (MR) imaging system, including a housing. The housing including an array of magnets positioned to project a low-field strength magnetic field into a region of interest, and a radio frequency (RF) coil assembly configured to selectively excite magnetization in the region of interest. The portable MR imaging system further includes an electronic device, a thermocouple positioned to monitor a temperature in the housing, a primary control circuit in signal communication with the thermocouple, and a safety control circuit in signal communication with the electronic device and the primary control circuit. The safety control circuit is to receive, from the primary control circuit, a temperature signal indicative of the temperature detected by the thermocouple, receive, from the electronic device, a status signal indicative of an operational parameter of the electronic device, and provide an electronic notification, via an interface, based on a condition. The condition is selected from a group consisting of the operational parameter being outside a predetermined range of values and the temperature being outside a predefined range of temperatures. The safety control circuit is further to transmit a stop scan signal to the primary control circuit based on the electronic notification being provided to the interface.

[0118] Example 2 - The portable MR imaging system of Example 1, wherein the electronic device comprises a RF power amplifier, wherein the RF power amplifier is configurable in a default configuration and an enabled configuration, wherein in the enabled configuration the RF power amplifier modifies an RF signal of the RF coil assembly, wherein in the default configuration the RF power amplifier does not modify the RF signal of the RF coil assembly, and wherein the operational parameter comprises a duty cycle of the RF power amplifier.

[0119] Example 3 - The portable MR imaging system of Example 2, wherein the safety control circuit is further to transmit, to the RF power amplifier, a disabling signal to transition the RF power amplifier from the enabled configuration to the default configuration based on the duty cycle being outside the predetermined range of values.

[0120] Example 4 - The portable MR imaging system of Examples 1, 2, or 3, wherein the interface comprises a graphical user interface.

[0121] Example 5 - The portable MR imaging system of Example 4, wherein the safety control circuit is further to evaluate the operational parameter, characterize the operational parameter as one of resettable or non-resettable, and transmit an electronic notification, via the graphical user interface, indicative of the characterization of the operational parameter.

[0122] Example 6 - The portable MR imaging system of Example 5, wherein the safety control circuit is further to automatically reset the portable MR imaging system based on the operational parameter being characterized as resettable.

[0123] Example 7 - The portable MR imaging system of Example 6, wherein automatically resetting the portable MR imaging system comprises powering down the portable MR imaging system for a predetermined time.

[0124] Example 8 - The portable MR imaging system of Examples 1, 2, 3, 4, 5, 6, or 7, wherein the interface comprises a status indicator to provide a user with a status of the portable MR imaging system. 318293876.1Attorney Docket No.230094PCT

[0125] Example 9 - The portable MR imaging system of Examples 1, 2, 3, 4, 5, 6, 7, or 8, wherein the interface comprises a series of LEDs.

[0126] Example 10 - The portable MR imaging system of Examples 1, 2, 3, 4, 5, 6, 7, 8, or 9, further comprising a power distribution unit to supply power to the electronic device and an interrupt control circuit in signal communication with the power distribution unit and the safety control circuit. The interrupt control circuit is to continuously receive, from the safety control circuit, a power enable signal and power the power distribution unit based on the power enable signal.

[0127] Example 11 - The portable MR imaging system of Example 10, wherein the interrupt control circuit comprises a switch, wherein the switch is closed based on the interrupt control circuit continuously receiving the power enable signal, and wherein the switch is opened to depower the power distribution unit based on the power enable signal not being received within a predetermined time period.

[0128] Example 12 - The portable MR imaging system of Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11, wherein the safety control circuit is further to stop transmitting the power enable signal based on the condition.

[0129] Example 13 - The portable MR imaging system of Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12, wherein the housing comprises a dome-shaped, head-optimized housing dimensioned to receive a head for neurological imaging.

[0130] Example 14 - The portable MR imaging system of Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13, wherein the operational parameter comprises at least one of a voltage supplied to the electronic device, a temperature condition of the electronic device, and a status of the electronic device.

[0131] Example 15 - A method of operating a portable MR imaging system including a housing, a thermocouple positioned to monitor a temperature in the housing, and an electronic device. The housing includes an array of permanent magnets and a RF coil assembly. The method includes receiving, by a primary control circuit, a user input to initiate a RF scan, wherein the primary control circuit is in signal communication with a safety control circuit, transmitting, from the primary control circuit, a temperature signal indicative of the temperature detected by the thermocouple to the safety control circuit, and receiving, by the safety control circuit, a status signal indicative of an operational parameter from the electronic device. The method includes transmitting, by the safety control circuit, to an interface, an electronic notification based on a condition selected from a group consisting of the operational parameter being outside a predefined range of values and the temperature being outside a predefined range of temperatures. The method further includes transmitting, by the safety control circuit, a stop scan signal to the primary control circuit based on the condition.

[0132] Example 16 - The method of Example 15, wherein the electronic device comprises a RF power amplifier, wherein the RF power amplifier is configurable in a default configuration and an enabled configuration, wherein in the enabled configuration the RF power amplifier modifies an RF signal of the RF coil assembly, wherein in the default configuration the RF power amplifier does not modify the RF signal of the RF coil assembly, wherein the operational parameter comprises a duty cycle of the RF power amplifier, and wherein the method further comprises transmitting, by the safety 318293876.1Attorney Docket No.230094PCT control circuit, to the RF power amplifier, a disabling signal to transition the RF power amplifier from the enabled configuration to the default configuration based on duty cycle being outside the predefined range of values.

[0133] Example 17 - The method of Example 15 or 16, further including evaluating, by the safety control circuit, the operational parameter, characterizing, by the safety control circuit, the operational parameter as one of resettable or non-resettable, and transmitting, by the safety control circuit, an electronic notification, via the interface, indicative of the characterization of the operational parameter.

[0134] Example 18 - The method of Example 17, further including resetting, automatically, by the safety control circuit, the portable MR imaging system based on the operational parameter being characterized as resettable, wherein automatically resetting the portable MR imaging system comprises powering down the portable MR imaging system for a predetermined time.

[0135] Example 19 - The method of Examples 15, 16, 17, or 18, wherein the portable MR imaging system further comprises a power distribution unit to supply power to the electronic device and an interrupt control circuit in signal communication with the power distribution unit and the safety control circuit, and wherein the interrupt control circuit comprises a switch. The method further including transmitting, continuously, by the safety control circuit, a power enable signal to the interrupt control circuit, maintaining, by the interrupt control circuit, the switch in a closed position allowing power to reach the power distribution unit based on receiving the power enable signal, stopping, by the safety control circuit, transmission of the power enabling signal based on the condition, and transitioning, by the interrupt control circuit, the switch to an open position cutting power to the power distribution unit based on not receiving the power enabling signal within a predetermined amount of time.

[0136] Example 20 - The method of Examples 15, 16, 17, 18, or 19, wherein the housing further comprises a dome-shaped, head-optimized housing dimensioned to receive a head for neurological imaging.

[0137] Example 21 - A portable magnetic resonance (MR) imaging system, including a housing. The housing including an array of magnets positioned to project a low-field strength magnetic field into a region of interest, a radio frequency (RF) coil assembly configured to selectively excite magnetization in the region of interest, and a RF power amplifier in signal communication with the RF coil assembly. The RF power amplifier is configurable from a default configuration to an enabled configuration. In the enabled configuration the RF power amplifier amplifies an output from the RF coil assembly. In the default configuration the RF power amplifier does not modify the output from the RF coil assembly. The portable MR imaging system further includes a primary control circuit in signal communication with the RF coil assembly, wherein the primary control circuit is to receive an initiate scan signal indicative of a user input to initiate a MR scan. The portable MR imaging system further includes a safety control circuit in signal communication with the RF power amplifier and the primary control circuit. The safety control circuit is to receive, from the primary control circuit, a scanning status signal, and transmit, to the RF power amplifier, an enabling signal to configure the RF power amplifier in the enabled configuration throughout a scan duration based on the scanning status signal.

[0138] Example 22 - The portable MR imaging system of Example 21, wherein the housing comprises a head-optimized, dome-shaped housing dimensioned for neurological imaging. 318293876.1Attorney Docket No.230094PCT

[0139] Example 23 - The portable MR imaging system of Examples 21 or 22, wherein the primary control circuit is further to transmit an end signal to the safety control circuit based on completion of at least one RF pulse sequence, and wherein the safety control circuit is to transmit, to the RF power amplifier, a disabling signal to configure the RF power amplifier in the default configuration based on receipt of the end signal.

[0140] Example 24 - The portable MR imaging system of Examples 21, 22, or 23, wherein the safety control circuit operates independently of the primary control circuit.

[0141] Example 25 - The portable MR imaging system of Examples 21, 22, 23, or 24, wherein the RF power amplifier is powered by a power distribution circuit in the default configuration.

[0142] Example 26 - The portable MR imaging system of Examples 21, 22, 23, 24, or 25, further comprising an interrupt circuit comprising a switch, wherein the interrupt circuit is in signal communication with the power distribution circuit and the safety control circuit, wherein the switch is moved to an open configuration based on detection of an out-of-range condition, and wherein, in the open configuration, the RF power amplifier is unpowered by the power distribution circuit.

[0143] Example 27 - The portable MR imaging system of Examples 21, 22, 23, 24, 25, or 26, further comprising a plurality of powered components, a power distribution circuit, and an interrupt circuit comprising a switch, wherein the power distribution circuit supplies power to the plurality of powered components, wherein the interrupt circuit is in signal communication with the power distribution circuit and the safety control circuit, wherein the switch is moved to an open configuration based on detection of an out-of-range condition, and wherein, in the open configuration, the plurality of powered components are unpowered by the power distribution circuit.

[0144] Example 28 - The portable MR imaging system of Example 21, 22, 23, 24, 25, 26, or 27, wherein the RF power amplifier comprises a power switch, and wherein the power switch is positioned in a closed position based the scanning status signal.

[0145] Example 29 - The portable MR imaging system of Example 8, further comprising a plurality of power amplifiers comprising the RF power amplifier, wherein each power amplifier comprises a normally-open switch.

[0146] Example 30 - A method of operating a portable MR imaging system including an array of permanent magnets, a RF coil assembly, and a RF power amplifier in signal communication with the RF coil assembly. The RF power amplifier is configurable in a default configuration and an enabled configuration. In the default configuration the RF power amplifier does not modify the RF signal of the RF coil assembly. In the enabled configuration the RF power amplifier modifies the RF signal of the RF coil assembly. The method including receiving, by a primary control circuit, a user input to initiate a RF scan, wherein the primary control circuit is in signal communication with a safety control circuit, transmitting, by the primary control circuit, a pulse frequency sequence to the RF coil assembly for a scan duration, and transmitting, by the primary control circuit, a scanning status signal to the safety control circuit. The method further includes transmitting, by the safety control circuit, an enabling signal to the RF power amplifier based on the scanning status signal, upon completion of the RF scan, transmitting, by the primary control circuit, a termination signal to the safety control circuit, 318293876.1Attorney Docket No.230094PCT receiving, by the safety control circuit, the termination signal, and transmitting, by the safety control circuit, a disabling signal to the RF power amplifier based on the termination signal.

[0147] Example 31 - The method of Example 30, further including transitioning the RF power amplifier from the default configuration to the enabled configuration based on receipt of the enabling signal from the safety control circuit, and transitioning the RF power amplifier from the enabled configuration to the default configuration based on receipt of the disabling signal from the safety control circuit.

[0148] Example 32 - The method of Examples 30 or 31, further comprising projecting an electromagnetic field into a region of interest defined by the array of permanent magnets throughout the scan duration, wherein the array of permanent magnets are housed in a head-optimized, dome- shaped housing, and wherein the RF scan is configured for neurological imaging.

[0149] Example 33 - The method of Examples 30, 31, or 32, further includes operating the safety control circuit independent of the primary control circuit.

[0150] Example 34 - The method of Examples 30, 31, 32, or 33, wherein the RF power amplifier comprises a power switch, and wherein the method further comprising positioning the power switch in a closed position for the scan duration.

[0151] Example 35 - The method of Example 30, 31, 32, 33, or 34, further including powering the RF power amplifier by a power distribution circuit, wherein the RF power amplifier is powered by the power distribution circuit in the default configuration and in the enabled configuration.

[0152] Example 36 - The method of Example 35, further including an interrupt circuit comprising a switch, wherein the interrupt circuit is in signal communication with the power distribution circuit and the safety control circuit, the method further comprising moving the switch from a closed position to an open position upon detection of an out-of-range condition by the safety control circuit, and wherein, in the open position, the RF power amplifier is unpowered by the power distribution circuit.

[0153] Example 37 - The method of Examples 30, 31, 32, 33, 34, 35, or 36 further comprising a plurality of powered components, a power distribution circuit, and an interrupt circuit comprising a switch, wherein the power distribution circuit supplies power to the plurality of powered components, wherein the interrupt circuit is in signal communication with the power distribution circuit and the safety control circuit, the method further comprising moving the switch from a closed position to an open position upon detection of an out-of-range condition by the safety control circuit, and wherein, in the open position, the plurality of powered components are unpowered by the power distribution circuit.

[0154] Though various aspects disclosed herein are directed to brain imaging and / or neurological interventions, the reader will appreciate that the various systems and methods disclosed herein can be used to image other portions of a patient’s anatomy and / or different structures in various instances.

[0155] While several forms have been illustrated and described, it is not the intention of Applicant to restrict or limit the scope of the appended claims to such detail. Numerous modifications, variations, changes, substitutions, combinations, and equivalents to those forms may be implemented and will occur to those skilled in the art without departing from the scope of the present disclosure. Moreover, 318293876.1Attorney Docket No.230094PCT the structure of each element associated with the described forms can be alternatively described as a means for providing the function performed by the element. Also, where materials are disclosed for certain components, other materials may be used. It is therefore to be understood that the foregoing description and the appended claims are intended to cover all such modifications, combinations, and variations as falling within the scope of the disclosed forms. The appended claims are intended to cover all such modifications, variations, changes, substitutions, modifications, and equivalents.

[0156] The foregoing detailed description has set forth various forms of the devices and / or processes via the use of block diagrams, flowcharts, and / or examples. Insofar as such block diagrams, flowcharts, and / or examples contain one or more functions and / or operations, it will be understood by those within the art that each function and / or operation within such block diagrams, flowcharts, and / or examples can be implemented, individually and / or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. Those skilled in the art will recognize that some aspects of the forms disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, 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 as virtually any combination thereof, and that designing the circuitry and / or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein are capable of being distributed as one or more program products in a variety of forms, and that an illustrative form of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution.

[0157] Instructions used to program logic to perform various disclosed aspects can be stored within a memory in the system, such as dynamic random access memory (DRAM), cache, flash memory, or other storage. Furthermore, the instructions can be distributed via a network or by way of other computer readable media. Thus a machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer), but is not limited to, floppy diskettes, optical disks, compact disc, read-only memory (CD-ROMs), and magneto-optical disks, read-only memory (ROMs), random access memory (RAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic or optical cards, flash memory, or a tangible, machine-readable storage used in the transmission of information over the Internet via electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.). Accordingly, the non-transitory computer- readable medium includes any type of tangible machine-readable medium suitable for storing or transmitting electronic instructions or information in a form readable by a machine (e.g., a computer).

[0158] As used in any aspect herein, the term “control circuit” may refer to, for example, hardwired circuitry, programmable circuitry (e.g., a computer processor including one or more individual instruction processing cores, processing unit, processor, microcontroller, microcontroller unit, controller, digital signal processor (DSP), programmable logic device (PLD), programmable logic array (PLA), or field programmable gate array (FPGA)), state machine circuitry, firmware that stores 318293876.1Attorney Docket No.230094PCT instructions executed by programmable circuitry, and any combination thereof. The control circuit may, collectively or individually, be embodied as circuitry that forms part of a larger system, for example, an integrated circuit (IC), an application-specific integrated circuit (ASIC), a system on-chip (SoC), desktop computers, laptop computers, tablet computers, servers, smart phones, etc. Accordingly, as used herein “control circuit” includes, but is not limited to, electrical circuitry having at least one discrete electrical circuit, electrical circuitry having at least one integrated circuit, electrical circuitry having at least one application specific integrated circuit, electrical circuitry forming a general purpose computing device configured by a computer program (e.g., a general purpose computer configured by a computer program which at least partially carries out processes and / or devices described herein, or a microprocessor configured by a computer program which at least partially carries out processes and / or devices described herein), electrical circuitry forming a memory device (e.g., forms of random access memory), and / or electrical circuitry forming a communications device (e.g., a modem, communications switch, or optical-electrical equipment). Those having skill in the art will recognize that the subject matter described herein may be implemented in an analog or digital fashion or some combination thereof.

[0159] As used in any aspect herein, the term “logic” may refer to an app, software, firmware and / or circuitry configured to perform any of the aforementioned operations. Software may be embodied as a software package, code, instructions, instruction sets and / or data recorded on non-transitory computer readable storage medium. Firmware may be embodied as code, instructions or instruction sets and / or data that are hard-coded (e.g., nonvolatile) in memory devices.

[0160] As used in any aspect herein, the terms “component,” “system,” “module” and the like can refer to a control circuit computer-related entity, either hardware, a combination of hardware and software, software, or software in execution.

[0161] As used in any aspect herein, an “algorithm” refers to a self-consistent sequence of steps leading to a desired result, where a “step” refers to a manipulation of physical quantities and / or logic states which may, though need not necessarily, take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It is common usage to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. These and similar terms may be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities and / or states.

[0162] A network may include a packet switched network. The communication devices may be capable of communicating with each other using a selected packet switched network communications protocol. One example communications protocol may include an Ethernet communications protocol which may be capable permitting communication using a Transmission Control Protocol / Internet Protocol (TCP / IP). The Ethernet protocol may comply or be compatible with the Ethernet standard published by the Institute of Electrical and Electronics Engineers (IEEE) titled “IEEE 802.3 Standard”, published in December, 2008 and / or later versions of this standard. Alternatively or additionally, the communication devices may be capable of communicating with each other using an X.25 communications protocol. The X.25 communications protocol may comply or be compatible with a standard promulgated by the International Telecommunication Union-Telecommunication 318293876.1Attorney Docket No.230094PCT Standardization Sector (ITU-T). Alternatively or additionally, the communication devices may be capable of communicating with each other using a frame relay communications protocol. The frame relay communications protocol may comply or be compatible with a standard promulgated by Consultative Committee for International Telegraph and Telephone (CCITT) and / or the American National Standards Institute (ANSI). Alternatively or additionally, the transceivers may be capable of communicating with each other using an Asynchronous Transfer Mode (ATM) communications protocol. The ATM communications protocol may comply or be compatible with an ATM standard published by the ATM Forum titled “ATM-MPLS Network Interworking 2.0” published August 2001, and / or later versions of this standard. Of course, different and / or after-developed connection-oriented network communication protocols are equally contemplated herein.

[0163] Unless specifically stated otherwise as apparent from the foregoing disclosure, it is appreciated that, throughout the foregoing disclosure, discussions using terms such as “processing,” “computing,” “calculating,” “determining,” “displaying,” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.

[0164] One or more components may be referred to herein as “configured to,” “configurable to,” “operable / operative to,” “adapted / adaptable,” “able to,” “conformable / conformed to,” etc. Those skilled in the art will recognize that “configured to” can generally encompass active-state components and / or inactive-state components and / or standby-state components, unless context requires otherwise.

[0165] The terms “proximal” and “distal” are used herein with reference to a clinician manipulating the handle portion of the surgical instrument. The term “proximal” refers to the portion closest to the clinician and the term “distal” refers to the portion located away from the clinician. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical”, “horizontal”, “up”, and “down” may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and / or absolute.

[0166] Those skilled in the art will recognize that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and / or “an” should typically be interpreted to mean “at least one” 318293876.1Attorney Docket No.230094PCT or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations.

[0167] In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). It will be further understood by those within the art that typically a disjunctive word and / or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase “A or B” will be typically understood to include the possibilities of “A” or “B” or “A and B.”

[0168] With respect to the appended claims, those skilled in the art will appreciate that recited operations therein may generally be performed in any order. Also, although various operational flow diagrams are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise.

[0169] It is worthy to note that any reference to “one aspect,” “an aspect,” “an exemplification,” “one exemplification,” and the like means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, appearances of the phrases “in one aspect,” “in an aspect,” “in an exemplification,” and “in one exemplification” in various places throughout the specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more aspects.

[0170] Any patent application, patent, non-patent publication, or other disclosure material referred to in this specification and / or listed in any Application Data Sheet is incorporated by reference herein, to the extent that the incorporated materials is not inconsistent herewith. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material 318293876.1Attorney Docket No.230094PCT set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.

[0171] In summary, numerous benefits have been described which result from employing the concepts described herein. The foregoing description of the one or more forms has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more forms were chosen and described in order to illustrate principles and practical application to thereby enable one of ordinary skill in the art to utilize the various forms and with various modifications as are suited to the particular use contemplated. It is intended that the claims submitted herewith define the overall scope. 318293876.1

Claims

Attorney Docket No.230094PCT WHAT IS CLAIMED IS:

1. A portable magnetic resonance (MR) imaging system, comprising: a housing, comprising: an array of magnets positioned to project a low-field strength magnetic field into a region of interest; and a radio frequency (RF) coil assembly configured to selectively excite magnetization in the region of interest; an electronic device; a thermocouple positioned to monitor a temperature in the housing; a primary control circuit in signal communication with the thermocouple; and a safety control circuit in signal communication with the electronic device and the primary control circuit, wherein the safety control circuit is to: receive, from the primary control circuit, a temperature signal indicative of the temperature detected by the thermocouple; receive, from the electronic device, a status signal indicative of an operational parameter of the electronic device; provide an electronic notification, via an interface, based on a condition, wherein the condition is selected from a group consisting of: the operational parameter being outside a predetermined range of values; and the temperature being outside a predefined range of temperatures; and transmit a stop scan signal to the primary control circuit based on the electronic notification being provided to the interface.

2. The portable MR imaging system of Claim 1, wherein the electronic device comprises a RF power amplifier, wherein the RF power amplifier is configurable in a default configuration and an enabled configuration, wherein in the enabled configuration the RF power amplifier modifies an RF signal of the RF coil assembly, wherein in the default configuration the RF power amplifier does not modify the RF signal of the RF coil assembly, and wherein the operational parameter comprises a duty cycle of the RF power amplifier.

3. The portable MR imaging system of Claim 2, wherein the safety control circuit is further to transmit, to the RF power amplifier, a disabling signal to transition the RF power amplifier from the enabled configuration to the default configuration based on the duty cycle being outside the predetermined range of values.

4. The portable MR imaging system of Claim 1, wherein the interface comprises a graphical user interface.

5. The portable MR imaging system of Claim 4, wherein the safety control circuit is further to: 318293876.1Attorney Docket No.230094PCT evaluate the operational parameter; characterize the operational parameter as one of resettable or non-resettable; and transmit an electronic notification, via the graphical user interface, indicative of the characterization of the operational parameter.

6. The portable MR imaging system of Claim 5, wherein the safety control circuit is further to automatically reset the portable MR imaging system based on the operational parameter being characterized as resettable.

7. The portable MR imaging system of Claim 6, wherein automatically resetting the portable MR imaging system comprises powering down the portable MR imaging system for a predetermined time.

8. The portable MR imaging system of Claim 1, wherein the interface comprises a status indicator to provide a user with a status of the portable MR imaging system.

9. The portable MR imaging system of Claim 1, wherein the interface comprises a series of LEDs.

10. The portable MR imaging system of Claim 1, further comprising: a power distribution unit to supply power to the electronic device; and an interrupt control circuit in signal communication with the power distribution unit and the safety control circuit, the interrupt control circuit is to: continuously receive, from the safety control circuit, a power enable signal; and power the power distribution unit based on the power enable signal.

11. The portable MR imaging system of Claim 10, wherein the interrupt control circuit comprises a switch, wherein the switch is closed based on the interrupt control circuit continuously receiving the power enable signal, and wherein the switch is opened to depower the power distribution unit based on the power enable signal not being received within a predetermined time period.

12. The portable MR imaging system of Claim 11, wherein the safety control circuit is further to stop transmitting the power enable signal based on the condition.

13. The portable MR imaging system of Claim 1, wherein the housing comprises a dome-shaped, head-optimized housing dimensioned to receive a head for neurological imaging.

14. The portable MR imaging system of Claim 1, wherein the operational parameter comprises at least one of a voltage supplied to the electronic device, a temperature condition of the electronic device, and a status of the electronic device. 318293876.1Attorney Docket No.230094PCT 15. A method of operating a portable MR imaging system comprising a housing, a thermocouple positioned to monitor a temperature in the housing, and an electronic device, wherein the housing comprises an array of permanent magnets and a RF coil assembly, the method comprising: receiving, by a primary control circuit, a user input to initiate a RF scan, wherein the primary control circuit is in signal communication with a safety control circuit; transmitting, from the primary control circuit, a temperature signal indicative of the temperature detected by the thermocouple to the safety control circuit; receiving, by the safety control circuit, a status signal indicative of an operational parameter from the electronic device; transmitting, by the safety control circuit, to an interface, an electronic notification based on a condition selected from a group consisting of: the operational parameter being outside a predefined range of values; and the temperature being outside a predefined range of temperatures; and transmitting, by the safety control circuit, a stop scan signal to the primary control circuit based on the condition.

16. The method of Claim 15, wherein the electronic device comprises a RF power amplifier, wherein the RF power amplifier is configurable in a default configuration and an enabled configuration, wherein in the enabled configuration the RF power amplifier modifies an RF signal of the RF coil assembly, wherein in the default configuration the RF power amplifier does not modify the RF signal of the RF coil assembly, wherein the operational parameter comprises a duty cycle of the RF power amplifier, and wherein the method further comprises transmitting, by the safety control circuit, to the RF power amplifier, a disabling signal to transition the RF power amplifier from the enabled configuration to the default configuration based on duty cycle being outside the predefined range of values.

17. The method of Claim 15, further comprising: evaluating, by the safety control circuit, the operational parameter; characterizing, by the safety control circuit, the operational parameter as one of resettable or non-resettable; and transmitting, by the safety control circuit, an electronic notification, via the interface, indicative of the characterization of the operational parameter.

18. The method of Claim 17, further comprising resetting, automatically, by the safety control circuit, the portable MR imaging system based on the operational parameter being characterized as resettable, wherein automatically resetting the portable MR imaging system comprises powering down the portable MR imaging system for a predetermined time.

19. The method of Claim 15, wherein the portable MR imaging system further comprises a power distribution unit to supply power to the electronic device and an interrupt control circuit in signal 318293876.1Attorney Docket No.230094PCT communication with the power distribution unit and the safety control circuit, and wherein the interrupt control circuit comprises a switch, the method further comprising: transmitting, continuously, by the safety control circuit, a power enable signal to the interrupt control circuit; maintaining, by the interrupt control circuit, the switch in a closed position allowing power to reach the power distribution unit based on receiving the power enable signal; stopping, by the safety control circuit, transmission of the power enabling signal based on the condition; and transitioning, by the interrupt control circuit, the switch to an open position cutting power to the power distribution unit based on not receiving the power enabling signal within a predetermined amount of time.

20. The method of Claim 15, wherein the housing further comprises a dome-shaped, head-optimized housing dimensioned to receive a head for neurological imaging. 318293876.1

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