Linear motor assembly for X-ray computed tomography system

Abstract

An x-ray system for at least one of breast examination and treatment includes a base component, a table configured to support a patient in a prone position and positioned proximate to the base component with a space therebetween, a rotatable x-ray assembly positioned between the base component and the table, and a linear motor assembly operatively connected to the rotatable x-ray assembly and the base component and configured to rotate the rotatable x-ray assembly relative to the base component during operation, wherein the rotatable x-ray assembly rotates at least partially around an active space area, and the table defines an opening through which a breast is positioned such that it extends at least partially downwardly into the active space area.

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION The presently claimed embodiments of the present invention relate to systems and components for breast examination and treatment, and more particularly to systems including linear motors.

[0002] This application claims priority to U.S. Application No. 17 / 942,895, filed September 12, 2022, which is incorporated herein by reference in its entirety. [Background technology]

[0003] The current state-of-the-art in breast imaging is typically digital mammography, sometimes combined with limited-angle tomography (also known as breast tomosynthesis). However, the breast imaging community has recognized that these two-dimensional or pseudo-three-dimensional imaging modalities do not adequately address the needs for breast cancer detection, diagnosis, and evaluation. Several organizations have been investigating the use of principles of computed tomography in breast imaging. These exams typically involve imaging one breast at a time while the patient lies face-down on a table, with the breast hanging through a hole in the table (the so-called pendant position). An X-ray CT system then rotates around the pendant breast, acquiring data that is then reconstructed into a three-dimensional image.

[0004] However, such conventional breast CT systems suffer from large and lacking angular rotation precision, due at least in part to the influence of the motor assembly. Therefore, there remains a need for improved breast CT systems. Summary of the Invention

[0005] One embodiment of the present invention is an X-ray system for at least one of breast examination and treatment. The X-ray system includes a base component, a table configured to support a patient in a prone position and positioned adjacent to and spaced from the base component, a rotatable X-ray assembly positioned between the base component and the table, and a linear motor assembly operatively connected to the rotatable X-ray assembly and the base component and configured to rotate the rotatable X-ray assembly relative to the base component during operation. The rotatable X-ray assembly rotates at least partially around an active volume, and the table defines an opening through which a breast is positioned such that it extends at least partially downward into the active volume.

[0006] Another embodiment of the present invention is an assembly for use in an x-ray system for at least one of breast examination and treatment. The assembly includes a base component, a rotatable x-ray assembly disposed in spaced relation to the base component, and a linear motor assembly operatively connected to the base component and the rotatable x-ray assembly and configured to rotate the rotatable x-ray assembly relative to the base component during operation. The rotatable x-ray assembly includes a shielded housing defining an interior region, an x-ray source mounted to the shielded housing and configured to irradiate at least a portion of an active volume region with an x-ray beam, an x-ray detector mounted to the shielded housing, and an x-ray detector configured to receive at least a portion of the x-ray beam after it passes through the active volume region. The shielded housing sufficiently attenuates x-rays from the x-ray source to comply with radiation safety standards without requiring further shielding for personnel to be in proximity to the shielded housing during operation of the x-ray system.

[0007] Another embodiment of the present invention is a method of manufacturing an X-ray system for at least one of breast examination and treatment. The method includes providing a base component and disposing a table adjacent to and spaced from the base component, the table configured to support a patient in a prone position. The method further includes disposing a rotatable X-ray assembly between the base component and the table and connecting a linear motor assembly to the rotatable X-ray assembly and the base component to rotate the rotatable X-ray assembly relative to the base component. The rotatable X-ray assembly rotates at least partially around an active space area, and the table defines an opening positioned and sized to allow a subject to lie prone with a breast pendant hanging therefrom and at least partially enter the active space area.

[0008] Another embodiment of the invention is a method of performing a breast procedure. The method includes receiving x-ray data acquired from a rotatable x-ray assembly disposed between a table configured to support a patient in a prone position and a base component. The method further includes receiving information from an encoder assembly disposed near a linear motor assembly operatively connected to the rotatable x-ray assembly and the base component, the encoder assembly rotating the rotatable x-ray assembly relative to the base component during operation of the x-ray assembly. The method further includes determining at least one of a rotational amount and a rotational position of the rotatable x-ray assembly during acquisition of x-ray data, and generating a plurality of x-ray images based on the received x-ray data and the determined rotational amount and at least one of the rotational position of the rotatable x-ray assembly.

[0009] Further objects and advantages will become apparent from a consideration of the description, drawings, and examples. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 shows a schematic diagram of some embodiments of an X-ray system for breast examination and treatment. [Figure 2A] FIG. 2A illustrates an example of a linear motor assembly according to some embodiments. [Figure 2B] FIG. 2B shows an exploded view of the linear motor assembly of FIG. 2A. [Figure 2C] FIG. 2C illustrates another example of a linear motor assembly according to some embodiments. [Figure 3] FIG. 3 illustrates a coil assembly according to some embodiments. [Figure 4] FIG. 4 illustrates an encoder assembly according to some embodiments. [Figure 5A] FIG. 5A illustrates an encoder scale according to some embodiments. [Figure 5B] FIG. 5B shows a detailed view of the encoder scale of FIG. 5A. [Figure 6A] FIG. 6A illustrates a magnetic rail assembly of some embodiments. [Figure 6B] FIG. 6B shows a detailed view of a magnetic rail for the magnetic rail assembly of FIG. 6A. [Figure 7] FIG. 7 illustrates an example of a linear motor assembly configuration according to some embodiments. [Figure 8] FIG. 8 illustrates another example of a linear motor assembly configuration according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0011] Several embodiments of the present invention are described in detail below. In describing the embodiments, specific terminology is used for the sake of clarity. However, the present invention is not intended to be limited to the specific terminology so selected. Furthermore, those skilled in the relevant art will recognize that other equivalent components can be used and other methods can be developed without departing from the broad concept of the present invention.

[0012] All references, whether cited anywhere in this specification, including the Background and Detailed Description sections, are incorporated by reference as if each were individually incorporated.

[0013] The term "linear motor" as used herein refers, in one sense, to a type of electric motor in which the stator and rotor are "unwound." For example, a linear motor does not produce torque (rotation), but rather produces a linear force along its length. The length of a linear motor can be arranged as a straight line or a curve. A synchronous linear motor is a type of linear motor with a fixed magnetic rail that acts as the stator and a moving electromagnetic coil that acts as the rotor.

[0014] The term "active volume" refers to a volume in which at least a portion of an object or subject can be positioned during X-ray breast examination and treatment. For example, the active volume is defined by the field of view (FOV) of an imaging detector, and is referred to as the "imaging FOV."

[0015] The term "base component" refers to the structural foundation of the rotating assembly. For example, the base component may support the bearings of a rotating gantry. In some embodiments, the base component may rest on the floor of the room in which the rotating assembly is located, or may itself be the floor. The term "base support" may be used interchangeably with the term "base component."

[0016] In some embodiments, an "X-ray assembly" may include an X-ray source and / or an X-ray detector. In some embodiments, the X-ray assembly may also include a rotating gantry to which the X-ray source and X-ray detector are mounted. For example, in some embodiments, the X-ray detector may be a flat panel detector. In some embodiments, the X-ray assembly includes a shield that substantially encloses the X-ray source and the X-ray detector. The term "rotating X-ray assembly" includes, but is not limited to, systems for computed tomography (CT), cone beam CT (CBCT), fan beam CT, radiation therapy (e.g., X-ray therapy), and X-ray surgery (e.g., biopsy).

[0017] The term "shielding enclosure" refers to an enclosure that substantially encloses the X-ray source and X-ray detector of an X-ray device and provides radiation protection to persons in the vicinity of the X-ray device. In some embodiments, the radiation shielding enclosure described in U.S. Patent Application No. 17 / 727,540 can be used. U.S. Patent Application No. 17 / 727,540, filed April 22, 2022, is incorporated herein by reference in its entirety.

[0018] The term "runout" refers to the maximum amount a rotating surface changes as it rotates about an axis. Runout refers to both the amount of change in the surface and the amount of change in the axial dimension when the part is rotated. Both the radial and axial changes are measured and kept within tolerances specified during manufacture. These variations are referred to as "stacked" because they are cumulative.

[0019] 1 illustrates an example of some embodiment X-ray system 100 for breast examination and treatment. X-ray system 100 includes a table 102 configured to support a patient 104 in a prone position with an opening 105 positioned such that the patient's breast 106 extends downward through the opening 105 into the active volume, also referred to as the field of view (FOV), of X-ray system 100.

[0020] X-ray system 100 includes a rotatable X-ray assembly 107 positioned in spare space below table 102. X-ray assembly 107 includes, for example, at least one X-ray source 108 that generates an X-ray beam 110 and an X-ray detector 112. In various embodiments, X-ray detector 112 is a flat panel detector, X-ray beam 110 is a cone beam, and X-ray system 100 may be configured to perform cone beam computed tomography.

[0021] At least one X-ray source 108 is positioned to irradiate at least a portion of a field of view encompassing the breast 106 with an X-ray beam 110. An X-ray detector 112 is positioned to receive at least a portion of the X-ray beam 110 after passing through the field of view and at least a portion of the breast 106. The X-ray beam 110 is collimated by a collimator 116 before irradiating at least a portion of the breast 106, and then is irradiated onto the X-ray detector 112.

[0022] Gantry assembly 118 is disposed below table 102 and includes a linear motor assembly 165 operatively connected to gantry platform 125, base 160, and rotatable X-ray assembly 107. In operation, linear motor assembly 165 applies a torque to gantry platform 125 to rotate gantry platform 125 relative to base 160 about breast 106 and a surrounding active volume (e.g., imaging FOV). In some embodiments, X-ray source 108 and X-ray detector 112 are rigidly mounted to gantry platform 125 and also rotate about breast 106 and the imaging field of view while gantry platform 125 is rotated by linear motor assembly 165.

[0023] In some embodiments, the X-ray system 100 may include a static subsystem (e.g., fixed components of the X-ray system 100 including, but not limited to, the table 102) and a rotational subsystem (e.g., rotatable components of the X-ray system 100 including, but not limited to, the X-ray source 108 and the X-ray detector 112) that is rotated by the linear motor assembly 165.

[0024] In some embodiments, the linear motor assembly 165 is an electromagnetic motor that includes components such as magnetic rails and magnetic coils. The linear motor assembly 165 may also include a position encoder, for example, an external high-precision encoder. The linear motor assembly 165 may also include bearings (see FIG. 2B) that can provide stiffness to the rotational subsystem based on the force and moment loads applied to the rotational subsystem.

[0025] The linear motor assembly 165 of some embodiments may offer many advantages over other types of motors, such as shaft-driven motors, including, but not limited to, some or all of the following: providing a compact motor height (allowing for lowering the patient table for improved accessibility and user comfort), custom-designed stiffness response of the bearings depending on the operating mode or application of the X-ray system 100 (e.g., breast exam, procedure), high positional accuracy through quantified angular measurements with a large effective turning radius (to properly reconstruct CT images acquired at various fields of view of the breast), high torque with fewer coils due to the large effective radius (sufficient to rotate the weight of the gantry and the imaging system it supports), and improved cost efficiency.

[0026] In some embodiments, the X-ray system 100 also includes a shielding enclosure (not shown in FIG. 1 ) that substantially encloses the X-ray source 108, the X-ray detector 112, and the imaging field of view. Thus, during operation of the X-ray system 100, the shielding enclosure also substantially encloses the X-ray beam 110 generated by the X-ray source 108. The shielding enclosure attenuates X-rays from the X-ray source 108 sufficiently to allow a person to be in close proximity to the shielding enclosure during operation of the X-ray system 100 without additional shielding, while still complying with radiation safety standards. The shielding enclosure is rigidly attached to the gantry platform 125, allowing it to rotate around the breast 106 along with the X-ray source 108 and the X-ray detector 112.

[0027] Several embodiments of linear motor assemblies for x-ray systems are described, and wherever possible, the same reference numerals are used to refer to the same or similar components. Various features described in any of the embodiments described herein may also be applied to and used in the other embodiments.

[0028] Figure 2A shows some embodiments of a linear motor assembly 200. Figure 2B is an exploded view of the linear motor assembly 200. In this example, the linear motor assembly 200 is provided with two coil assemblies 205a, 205b and an encoder assembly 215. While two coil assemblies are shown, in other embodiments there may be one coil assembly or more than two coil assemblies. The coil assemblies 205a, 205b function as the rotors of the linear motor assembly 200.

[0029] In this example, coil assemblies 205a, 205b and encoder assembly 215 of linear motor assembly 200 are rigidly mounted to gantry platform 225 (also referred to as a gantry plate or gantry support). Coil assemblies 205a, 205b are positioned on opposite sides of gantry platform 225, separated by a distance D (see FIG. 2A). This distance defines the effective turning radius of linear motor assembly 200 (e.g., equal to D / 2). Encoder scale 235 is positioned below gantry platform 225 and is readable by encoder assembly 215. Gantry platform 225 is supported on and rotates on bearing 245. Magnet ring assembly 250, comprised of magnetic rails 255, is positioned around bearing 245 and near coil assemblies 205a, 205b to generate torque on bearing 245 during operation of coil assemblies 205a, 205b. This allows the magnetic rail 255 to function as a stator for the linear motor assembly 200. At least a portion of the linear motor assembly 200 is supported by a fixed, electrically grounded base support 260.

[0030] In some embodiments, the X-ray system 100 also includes a data processor 270 communicatively coupled to the encoder assembly 215 and configured to determine, based on information received from the encoder assembly 215, at least one of the amount of rotation and the rotational position of the gantry platform 225, and accordingly, the amount of rotation and the rotational position of any X-ray assembly mounted thereon.

[0031] In some embodiments, the linear motor assembly 200 is configured to rotate between 6 and 12 revolutions per minute (RPM). In some embodiments, the linear motor assembly 200 is configured to support an axial load (downward along the axis of rotation) of up to 500 pounds, or 300 kilograms, due to the additional weight of components mounted on the gantry platform 225. When the axial load on the gantry platform 225 is perfectly balanced, the moment load on the bearing 245 is zero. When the axial load on the gantry platform 225 is imperfectly balanced, the total load on the bearing 245 includes a non-zero moment load in addition to the axial load. When a radial load (inward) is applied: If a radial load perpendicular to the axis of rotation is present, the radial load may also contribute to the total load on the bearing. The linear motor assembly 200 can be configured and balanced to significantly reduce moment loads and virtually eliminate radial loads.

[0032] In some embodiments, the number of coil assemblies is defined by the motor torque, which is driven by several attributes of the linear motor assembly 200, including but not limited to bearing friction load torque, gantry inertia torque, velocity, acceleration, and linear motor cogging torque. The coil assemblies 205a, 205b may be equally spaced on the effective turning radius so as not to add additional moment to the bearing 245, or may be unequally spaced to provide counter moment as needed for other components, such as the X-ray assembly 107.

[0033] 2C illustrates an alternative configuration for some embodiments of a linear motor assembly 300. In this example, the linear motor assembly 300 includes three coil assemblies 305a, 305b, and 305c mounted to the gantry platform 225 and an encoder assembly 315. The use of three coil assemblies provides more torque than a two-coil configuration, improving the precision of the rotational motion and improving the reaction moment against the bearings 245 (not shown in FIG. 2C).

[0034] FIG. 3 illustrates a coil assembly 305 according to some embodiments. The coil assembly 305 may be used for some or all of the coil assemblies 205a, 205b, 305a, 305b, 305c, 705 (FIG. 7), and 805 (FIG. 8), by way of non-limiting example. The coil assembly 305 includes a coil mount 307, a magnetic coil 309, and a Hall sensor 311. The coil mount 307 allows the coil assembly 305 to be securely mounted to either the gantry platform 225 (not shown in FIG. 3) or the base support 260. The Hall sensor 311 provides switching (called commutation) of the magnetic field of the magnetic coil 309, alternately attracting and repelling magnets in the magnetic rail 255 to create a consistently directional force against the magnetic rail 255 and propelling the rotor (magnetic coil 309) along the stator (magnetic rail 255). In the example shown in FIG. 3, the coil assembly 305 also includes an umbilical cable 313 that provides power and control signals to and from the magnetic coil 309 .

[0035] FIG. 4 illustrates some embodiments of an encoder assembly 415 positioned proximate to the linear motor assembly 400. The encoder assembly 415 can be used as part or all of the encoder assembly 215, encoder assembly 715 (FIG. 7), and encoder assembly 815 (FIG. 8), by way of non-limiting example. The encoder assembly 415 provides information regarding at least one of the amount of rotation and the rotational position of the rotatable X-ray assembly 107 relative to the base 160. In this example, the encoder assembly 415 includes an encoder sensor head 417 positioned toward a position encoder. For example, in some embodiments, the encoder sensor head 417 is an optical sensor, and the position encoder is an encoder scale 235 with a grating or marking that can be optically detected by the encoder sensor head 417. However, any suitable sensor and corresponding encoder scale can be used, such as a magnetic sensor, an electrical sensor, a radio frequency sensor, or the like. In some embodiments, the encoder assembly 415 is a transistor-transistor-logic (TTL) assembly that provides a constant output signal level when activated, regardless of the power supply voltage level. In the example of FIG. 4, the encoder assembly 415 includes a cable 419 that connects to a data processor (not shown), and the encoder assembly 415 provides an output signal to the data processor via the cable 419 .

[0036] FIG. 5A illustrates an encoder scale 535 according to some embodiments. The encoder scale 535 can be used as one or more of the encoder scales 235, 735 (FIG. 7), and 835 (FIG. 8), by way of non-limiting example. FIG. 5B illustrates a detailed view of a portion of the encoder scale 535 of FIG. 5A. In this example, the encoder scale 535 is a ring-shaped grating tape having a pitch grating 537 along its outer surface. By way of example, the pitch grating 537 is a 3-millimeter pitch grating with 540 counts evenly spaced around the circumference of the encoder scale 535, resulting in an angular resolution of less than ±0.32 degrees in some embodiments, and ±0.25 degrees or better in preferred embodiments. Additionally, in some embodiments, the encoder scale 535 also includes coding marks 539 that are unevenly spaced. Upon receiving a signal from the encoder assembly 415 (FIG. 4) indicating the detection of two consecutive coded marks 539, a data processor (not shown in FIG. 5B) may be configured to determine the absolute angular position of the encoder assembly 415. This absolute position can be used, for example, in a homing routine in which the linear motor is reset to a predefined angular position. In some embodiments, the data processor uses a lookup table to determine the absolute position based on which consecutive coded marks 539 are detected by the encoder assembly 415 during operation. The absolute position can be determined continuously or periodically in real time, or both, upon receiving instructions from a user.

[0037] FIG. 6A illustrates a magnetic rail assembly 650 of some embodiments. The magnetic rail assembly 650 can be used, by way of non-limiting example, as magnetic rail assembly 250. The magnetic rail assembly 650 includes multiple magnetic rails 655 arranged in a circle with an effective radius R. FIG. 6B illustrates a detailed view of an individual magnetic rail 655 of the magnetic rail assembly 650 of FIG. 3A. The magnetic rail 655 can be used, by way of non-limiting example, as one or more of magnetic rail 255, magnetic rail 755 (FIG. 7), and magnetic rail 855 (FIG. 8). In this example, each magnetic rail 655 is an assembly of eight permanent magnets with alternating polarities. Four of the permanent magnets are arranged with their north poles facing up, and the remaining four are arranged with their south poles facing up, alternating in polarity. In some embodiments, the magnetic rails 655 are electromagnets or other types of magnets rather than permanent magnets.

[0038] In other embodiments, each magnetic rail 655 may include a different number of permanent magnets. In this example, 16 such magnetic rails 655 are used to complete the circle. In other embodiments, the magnetic rails 655 may be different sizes (e.g., different numbers of permanent magnets in the magnetic rails 655 or different radii of curvature), and thus different numbers of magnetic rails 655 may be used to achieve different effective diameters D, depending on the design requirements of the X-ray system. The effective diameter D is designed to match the effective rotation radius of one or more coil assemblies during rotation of the gantry platform. For example, in the embodiment described above with reference to FIG. 2, two coil assemblies 205 are included at opposite ends of the gantry platform 225, separated by a distance D, and the effective diameter D is equal to the distance D.

[0039] 7 illustrates an example configuration of a linear motor assembly 700 according to some embodiments. The linear motor assembly 700 is similar in some respects to the linear motor assembly 200 embodiment described above with respect to FIGS. 2A and 2B, and like reference numerals are used to refer to the same or similar components. A detailed description of these components will be omitted, and the following description will focus on the differences between these embodiments.

[0040] The linear motor assembly 700 includes two coil assemblies 705 and an encoder assembly 715 that are rigidly mounted to a gantry platform 725 and rotate about an axis of rotation (indicated by dashed line 727). An x-ray assembly (not shown) is also rigidly mounted to the gantry platform 725 and is coupled to and rotates with the coil assemblies 705 and encoder assembly 715. The coil assemblies are spaced a distance D apart on opposite sides of the gantry platform 725, although in some embodiments the coil assemblies may be asymmetrically positioned around the gantry platform 725.

[0041] Alternatively, in some embodiments, the linear motor assembly 700 may include three or more coil assemblies rigidly mounted to and rotating with the gantry platform 725. In some such embodiments, the coil assemblies may be evenly spaced around the circumference of the gantry platform at a distance D / 2 from the axis of rotation. In other such embodiments, the coil assemblies may be asymmetrically spaced around the gantry platform 725.

[0042] The linear motor assembly 700 also includes an encoder scale tape 735 that is mounted on a fixed outer portion of a bearing 745 that rotatably supports the gantry platform 725. The encoder scale tape 735 is positioned so that it is always within the field of view of a sensor head (not shown) of the encoder assembly 715 during rotation of the gantry platform 725.

[0043] In this example, to minimize runout stackup, the encoder scale tape 735 is mounted directly to the bearing 745. In a different embodiment, the encoder scale tape 735 can be mounted to the rotating gantry platform 725, or it can be mounted to the base support 760 if machining the features on the bearing is not possible or feasible. In that case, the runout stackup will be larger and the tolerances of the gantry or bearing support will increase.

[0044] The bearing 745 is mounted on a fixed base support 760. A plurality of rings of magnetic rails 755, each defining an arc segment of a complete circle, are disposed on the base support 760 around the circumference of the bearing 745 and are further positioned to be aligned with the coil assemblies 705 during rotation of the gantry platform 725. In this example, the distance between the two coil assemblies 705 is equal to the effective diameter of the rings of magnetic rails 755. The magnetic rails 755 are mounted on the base support 760 outside the bearing 745, although in different embodiments the magnetic rails 755 may be mounted on the base support 760 inside the bearing 745.

[0045] The gantry platform 725 and inner portion of the bearing 745 are driven to rotate relative to the base support 760 by generating a circumferential electromagnetic force between the rotating coil assembly 705 and the fixed magnetic rails 755. During rotation of the gantry platform 725, the encoder assembly 715 rotates past the fixed encoder scale tape 735 and generates signals that are received by the processor 770. The processor 770 uses these signals to determine (e.g., in real time) the rotational angle and position of the gantry platform 725 relative to the base support 760 and to provide automatic "homing" commands for rotating the gantry platform 725 to a predetermined angular position.

[0046] In this configuration, electrical slip rings (not shown) are required to provide power and send and receive control commands to the coil assembly 705 and encoder assembly 715. Additional control electronics (e.g., motor amplifiers, not shown) and processor 770 are mounted on the rotating gantry to minimize the size of the slip rings and minimize the amount of cabling and wiring (not shown).

[0047] Figure 8 illustrates another example configuration of a linear motor assembly 800 according to some embodiments. Linear motor assembly 800 is similar in some respects to the linear motor assembly 200 embodiment described above with respect to Figure 7, and like reference numerals are used to refer to the same or similar components. A detailed description of these components will be omitted, and the following discussion will focus on the differences between these embodiments.

[0048] Similar to the linear motor assembly 700 described with reference to FIG. 7 , the linear motor assembly 800 includes two coil assemblies 805, an encoder assembly 815, a gantry platform 825, an encoder scale tape 835, bearings 845, magnetic rails 855, a fixed base support 860 that rotatably supports the gantry platform 825, and a processor 870. However, unlike the linear motor assembly 700, the example linear motor assembly 800 differs in that the ring of encoder scale tape 835 and magnetic rails 855 are coupled to the gantry platform 825 and rotate relative to the base support 860 about an axis of rotation (indicated by dashed line 827). An X-ray assembly (not shown) is also rigidly attached to the gantry platform 825 and is coupled to and rotates with the encoder scale tape 835 and magnetic rails 855. In this example, the encoder scale tape 835 is attached directly to the rotating outer portion of the bearings 845 to minimize runout tolerance stackup.

[0049] In this configuration, the coil assembly 805 and the encoder assembly 815 are mounted on a fixed base support 860. The encoder assembly 815 is positioned so that during rotation of the gantry platform 825, a sensor head (not shown) of the encoder assembly 815 always has a field of view that includes the encoder scale tape 835.

[0050] The rings of magnetic rails 855, each defining an arc segment of a complete circle, are mounted around the circumference of the gantry platform 825 and are further positioned to be aligned with the fixed coil assemblies 805 during rotation of the gantry platform 825. Again, the distance between the two coil assemblies 805 is equal to the effective diameter of the rings of magnetic rails 855. However, in some embodiments, the coil assemblies 805 may be positioned asymmetrically around the fixed base support 860.

[0051] Alternatively, in some embodiments, linear motor assembly 800 may include three or more coil assemblies mounted to fixed base support 860. In some such embodiments, the coil assemblies may be evenly spaced around the circumference of fixed base support 860 at a distance D / 2 from the axis of rotation. In other such embodiments, the coil assemblies may be asymmetrically spaced around fixed base support 860.

[0052] The gantry platform 825 and bearings 845 are driven to rotate relative to the base support 860 by generating a circumferential electromagnetic force between the stationary coil assembly 805 and the rotating magnetic rail 855. During rotation of the gantry platform 825, the stationary encoder scale tape 835 rotates past the encoder assembly 815, generating signals that are received by the processor 870. The processor 870 uses these signals to determine (e.g., in real time) the rotational angle and position of the gantry platform 825 relative to the base support 860 and to provide automatic "homing" commands for rotating the gantry platform 825 to a predetermined angular position.

[0053] In this configuration, power and control signals can be provided between the coil assembly 805 and the encoder assembly 815 via cable 880 without the need for slip rings. Additional control electronics (e.g., motor amplifiers, not shown) and processor 870 can be mounted external to the linear motor assembly 800.

[0054] The terms "light" and "optical" are intended to have broad meanings that can include not only the visible region of the electromagnetic spectrum, but also other regions such as, but not limited to, infrared and ultraviolet light, and optical images of such light.

[0055] The terms "computer," "server," "processor," and "memory" all refer to electronic or other technological devices. These terms exclude individuals or groups of people. As used herein, the terms "computer-readable medium," "computer-readable media," "machine-readable medium," and the like are strictly limited to tangible, physical objects that store information in a computer-readable form. These terms do not include wireless signals, wired download signals, and other ephemeral signals.

[0056] The term "computer" is intended to have a broad meaning that may be used to refer to computing devices such as standalone devices, client devices, server devices, etc. A computer may be, for example, but not limited to, a personal computer (PC) system running an operating system such as MICROSOFT® WINDOWS®, available from MICROSOFT® Corporation of Redmond, Washington, USA, or an Apple computer running MAC® OS, offered by Apple® of Cupertino, California, USA. However, the present invention is not limited to these platforms. Instead, the present invention may be implemented on any suitable computer system running any suitable operating system. In an exemplary embodiment, the present invention may be implemented on a computer system that operates as described herein. A computer system may include, for example, but not limited to, a main memory, a random access memory (RAM), and a secondary memory. The main memory, the random access memory (RAM), and the secondary memory may be a computer-readable medium configured to store instructions configured to implement one or more embodiments and may include a random access memory (RAM), including RAM devices such as dynamic RAM (DRAM) devices, flash memory devices, static RAM (SRAM) devices, etc.

[0057] Secondary storage devices include, but are not limited to, hard disk drives and / or removable storage drives (e.g., floppy disk drives, magnetic tape drives, optical disk drives, read-only compact discs (CD-ROMs), digital versatile discs (DVDs), flash memory (e.g., SD cards, mini SD cards, micro SD cards), read-only and recordable Blu-Ray® discs, etc.). Removable storage drives may, for example, but are not limited to, be capable of reading from and / or writing to removable storage units in well-known manners. Removable storage units may also be referred to as program storage devices or computer program products, and represent, but are not limited to, floppy disks, magnetic tapes, optical disks, compact discs, etc. that can be read from and written to removable storage drives. As will be appreciated, removable storage units may include computer-usable storage media having computer software and / or data stored thereon.

[0058] In some embodiments, secondary memory may include other similar devices that allow computer programs or other instructions to be loaded into a computer system. Such devices include, for example, removable storage units and interfaces. Examples of such devices include program cartridges and cartridge interfaces (such as those found in video game devices), removable memory chips (such as erasable programmable read-only memories (EPROMs)), or programmable read-only memories (PROMs) and associated sockets, and other removable storage units and interfaces that allow software and data to be transferred from removable storage units to a computer system.

[0059] Some embodiments include electronic components, such as a microprocessor, storage, and memory, that store computer program instructions on a machine-readable or computer-readable medium (also referred to as a computer-readable storage medium, machine-readable media, or machine-readable storage medium). The computer-readable medium stores a computer program that is executable by at least one processing unit and includes a set of instructions for performing various operations. Examples of computer programs or computer code include machine code produced by a compiler and files containing high-level code that are executed by a computer, electronic component, or microprocessor using an interpreter.

[0060] A computer also includes input devices, which may include any mechanism or combination of mechanisms that allow information to be input to a computer system, for example, from a user. An input device may include logic configured to receive information from a user to the computer system, for example. Examples of input devices include, but are not limited to, a mouse, a pen-based pointing device, other pointing devices such as a digitizer, a touch-sensitive display device, and / or a keyboard or other data input device (all not labeled). Other input devices include, but are not limited to, a biometric input device, a video source, an audio source, a microphone, a webcam, a video camera, and / or another camera. The input devices may communicate with the processor via wires or wirelessly.

[0061] A computer may also include output devices, which may include any mechanism or combination of mechanisms capable of outputting information from a computer system. An output device may include logic configured to output information from a computer system. Examples of output devices include, but are not limited to, displays and display interfaces (such as displays, printers, speakers, cathode ray tubes (CRTs), plasma displays, light-emitting diode (LED) displays, liquid crystal displays (LCDs), printers, vacuum fluorescent displays (VFDs), surface-conduction electron emission displays (SEDs), and field emission displays (FEDs)). A computer may also include input / output (I / O) devices, such as, but not limited to, communications interfaces, cables, and communications paths. These devices include, but are not limited to, network interface cards and modems. Output devices may communicate with the processor via wired or wireless connections. Communications interfaces allow software and data to be transferred between a computer system and external devices.

[0062] The term "data processor" is intended to have a broad meaning, including, but not limited to, one or more processors connected to a communications infrastructure (such as a communications bus, crossover bar, interconnect, network, etc.). The term data processor includes any type of processor, microprocessor, and / or processing logic capable of interpreting and executing instructions, such as an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA). A data processor may consist of a single device (e.g., a single core) and / or a group of multiple devices (e.g., multi-core). A data processor may include logic configured to execute computer-executable instructions configured to implement one or more embodiments. The instructions are stored in a main memory or a secondary memory. A data processor may also include multiple independent cores, such as a dual-core processor or a multi-core processor. A data processor may also include one or more graphics processing units (GPUs), which may take the form of a dedicated graphics card, an integrated graphics solution, and / or a hybrid graphics solution. Various exemplary software embodiments can be described in terms of this exemplary computer system. After reading this description, it will become apparent to those skilled in the relevant art how to implement the invention using other computer systems and / or architectures.

[0063] The term "data storage device" has a broad meaning, including removable storage drives, hard disks installed in hard disk drives, flash memory, removable disks, non-removable disks, etc. Furthermore, it should be noted that various electromagnetic radiations, such as wireless communications, electrical communications carried over conductive wires (e.g., twisted pair, CAT5, etc.) or optical media (e.g., fiber optics, etc.), may be encoded to carry computer-executable instructions and / or computer data that are embodiments of the present invention, for example, over a communications network. These computer program products may provide software to a computer system. It should be noted that a computer-readable medium containing computer-executable instructions for execution by a processor can be configured to store various embodiments of the present invention.

[0064] The term "network" includes any communication network, including a network such as a local area network ("LAN"), a wide area network ("WAN"), an intranet, or the Internet.

[0065] The term "software" includes firmware residing in read-only memory and applications stored on magnetic storage that are loaded into memory for processing by a processor. Also, in some embodiments, multiple software inventions may be implemented as subparts of a larger program while remaining separate software inventions. In some embodiments, multiple software inventions may be implemented as separate programs. Finally, any combination of separate programs that together implement a software invention as described herein is within the scope of the present invention. In some embodiments, a software program, when installed to operate on one or more electronic systems, defines one or more specific machine implementations that execute and perform the operations of the software program.

[0066] The embodiments shown and described herein are intended solely to teach those skilled in the art how to make and use the invention. In describing the embodiments of the invention, specific terminology is used for the sake of clarity. However, it is not intended that the invention be limited to the specific terminology so selected. The above-described embodiments of the invention can be modified or varied, as will be understood by those skilled in the art in light of the above teachings, without departing from the invention. It is therefore to be understood that, within the scope of the appended claims and their equivalents, the invention may be practiced other than as specifically described.

[0067] Furthermore, features described in connection with one embodiment may be used in combination with other embodiments, even if not explicitly stated above.

Claims

1. 1. An x-ray system for at least one of breast examination and treatment, comprising: A base component; a table configured to support a patient in a prone position, the table being positioned adjacent to the base component with a space therebetween; a rotatable x-ray assembly disposed between the base component and the table; a linear motor assembly operatively connected to the rotatable X-ray assembly and the base component, the linear motor assembly rotating the rotatable X-ray assembly relative to the base component during operation; the rotatable x-ray assembly rotates at least partially about an active space area, and the table defines an opening through which a breast is positioned such that it extends at least partially downwardly into the active space area. X-ray system.

2. the base component and the table are configured to be fixed relative to each other; The x-ray system of claim 1 .

3. the linear motor assembly includes a plurality of coil assemblies and a plurality of magnetic rails disposed proximate to the plurality of coil assemblies; the plurality of coil assemblies are rotors of the linear motor assembly; the plurality of magnetic rails are stators of the linear motor assembly; The x-ray system of claim 1 .

4. the plurality of coil assemblies are coupled to the rotatable X-ray assembly and rotate therewith, and the plurality of magnetic rails are coupled to the base component and remain stationary during rotation of the X-ray assembly.

4. The x-ray system of claim 3.

5. the plurality of magnetic rails are coupled to the rotatable X-ray assembly and rotate therewith, and the plurality of coil assemblies are coupled to the base component and remain stationary during rotation of the X-ray assembly.

4. The x-ray system of claim 3.

6. further comprising an encoder assembly disposed proximate the linear motor assembly; the encoder assembly is configured to provide information regarding at least one of a rotational amount and a rotational position of the rotatable X-ray assembly relative to the base component. The x-ray system of claim 1 .

7. a data processor communicatively coupled to the encoder assembly and configured to determine at least one of an amount of rotation and a rotational position of the rotatable X-ray assembly based on information received from the encoder assembly; the encoder assembly includes a sensor head, and the X-ray system further includes a scale tape.

7. The x-ray system of claim 6.

8. the sensor head is coupled to the rotatable X-ray assembly, the sensor head rotates relative to the base component, and the scale tape is coupled to the base component, the scale tape being stationary during rotation of the sensor head; 8. The x-ray system of claim 7.

9. the scale tape is coupled to the rotatable X-ray assembly, the scale tape rotating therewith relative to the base component; the sensor head is coupled to the base component, and the sensor head is stationary while the scale tape rotates; 8. The x-ray system of claim 7.

10. the rotatable X-ray assembly includes an X-ray source positioned to project an X-ray beam onto at least a portion of the active volume; an X-ray detector positioned to receive at least a portion of the X-ray beam after passing through the active volume; a gantry rotated by the linear motor assembly; the X-ray source and the X-ray detector are mounted to the gantry so as to rotate therewith; The x-ray system of claim 1 .

11. the x-ray detector is a flat panel detector, the x-ray beam is a cone beam, and the x-ray system is configured to perform cone beam computed tomography.

11. The x-ray system of claim 10.

12. the X-ray system further comprising a shielded enclosure substantially enclosing the X-ray source, the X-ray detector, and the active volume; the shielded enclosure sufficiently attenuates x-rays from the x-ray source so as to comply with radiation safety standards while a person is in the vicinity of the shielded enclosure during operation of the x-ray system without further shielding.

11. The x-ray system of claim 10.

13. 1. An assembly for use in an x-ray system for at least one of breast examination and treatment, comprising: A base component; a rotatable x-ray assembly positioned in spaced proximity to the base component; a linear motor assembly operatively connected to the base component and the rotatable X-ray assembly, for rotating the rotatable X-ray assembly relative to the base component during operation; The rotatable X-ray assembly includes: a shielded enclosure defining an interior region; an X-ray source attached to the shielded enclosure and configured to project an X-ray beam onto at least a portion of the active volume; an X-ray detector attached to the shielded housing; an X-ray detector configured to receive at least a portion of the X-ray beam after passing through the active volume; the shielded enclosure sufficiently attenuates x-rays from the x-ray source so as to comply with radiation safety standards while a person is in the vicinity of the shielded enclosure during operation of the x-ray system without further shielding. assembly.

14. the linear motor assembly includes a plurality of coil assemblies and a plurality of magnetic rails disposed proximate to the plurality of coil assemblies; the plurality of coil assemblies are rotors of the linear motor assembly; the plurality of magnetic rails are stators of the linear motor assembly; 14. The assembly of claim 13.

15. the plurality of coil assemblies are coupled to the rotatable X-ray assembly to rotate therewith, and the plurality of magnetic rails are coupled to the base component to remain stationary during rotation of the X-ray assembly.

15. The assembly of claim 14.

16. the plurality of magnetic rails are coupled to the rotatable X-ray assembly to rotate therewith, and the plurality of coil assemblies are coupled to the base component to remain stationary during rotation of the X-ray assembly.

15. The assembly of claim 14.

17. further comprising an encoder assembly disposed proximate to the linear motor assembly; the encoder assembly is configured to provide information regarding at least one of a rotational amount and a rotational position of the rotatable X-ray assembly relative to the base component.

14. The assembly of claim 13.

18. a data processor communicatively coupled to the encoder assembly and configured to determine at least one of an amount of rotation and a rotational position of the rotatable X-ray assembly based on information received from the encoder assembly; the encoder assembly includes a sensor head, the assembly further including a scale tape; 18. The assembly of claim 17.

19. the sensor head is coupled to the rotatable X-ray assembly, the sensor head rotating therewith relative to the base component; the scale tape is coupled to the base component, and the scale tape is stationary while the sensor head rotates; 19. The assembly of claim 18.

20. the scale tape is coupled to the rotatable X-ray assembly, the scale tape rotating therewith relative to the base component; the sensor head is coupled to the base component, and the sensor head is stationary while the scale tape rotates; 19. The assembly of claim 18.

21. the x-ray detector is a flat panel detector, the x-ray beam is a cone beam, and the x-ray system is configured to perform cone beam computed tomography.

14. The assembly of claim 13.

22. 1. A method of manufacturing an x-ray system for at least one of breast examination and treatment, comprising: Prepare the base components, a table configured to support a patient in a prone position and disposed adjacent to and spaced apart from the base component; disposing a rotatable x-ray assembly between the base component and the table; a linear motor assembly connected to the rotatable X-ray assembly and the base component and operable to rotate the rotatable X-ray assembly relative to the base component; the rotatable X-ray assembly rotates at least partially about an active volume; the table defines an opening positioned and sized to allow a subject to lie face down with a breast pendant hanging down and at least partially enter the active space area; A method for manufacturing an X-ray system.

23. the base component and the table are configured to be fixed relative to each other; 23. A method for manufacturing an x-ray system according to claim 22.

24. the linear motor assembly includes a plurality of coil assemblies and a plurality of magnetic rails disposed proximate to the plurality of coil assemblies; the plurality of coil assemblies are rotors of the linear motor assembly; the plurality of magnetic rails are stators of the linear motor assembly; 23. A method for manufacturing an x-ray system according to claim 22.

25. the plurality of coil assemblies are coupled to the rotatable X-ray assembly to rotate therewith, and the plurality of magnetic rails are coupled to the base component to remain stationary during rotation of the X-ray assembly.

25. A method for manufacturing an x-ray system according to claim 24.

26. the plurality of magnetic rails are coupled to the rotatable X-ray assembly to rotate therewith, and the plurality of coil assemblies are coupled to the base component to remain stationary during rotation of the X-ray assembly.

25. A method for manufacturing an x-ray system according to claim 24.

27. further comprising disposing an encoder assembly proximate the linear motor assembly; the encoder assembly is configured to provide information regarding at least one of a rotational amount and a rotational position of the rotatable X-ray assembly relative to the base component.

23. A method for manufacturing an x-ray system according to claim 22.

28. a data processor communicatively connected to the encoder assembly; and further configuring the data processor to determine at least one of an amount of rotation and a rotational position of the rotatable X-ray assembly based on information received from the encoder assembly.

28. A method for manufacturing an x-ray system according to claim 27.

29. 1. A method of performing a breast procedure, comprising: receiving the acquired x-ray data from a rotatable x-ray assembly, the rotatable x-ray assembly being disposed between the base component and a table configured to support a patient in a prone position; receiving information from an encoder assembly, the encoder assembly being disposed near a linear motor assembly operatively connected to the rotatable X-ray assembly and the base component, causing rotation of the rotatable X-ray assembly relative to the base component during operation of the X-ray assembly; determining at least one of an amount of rotation and a rotational position of the rotatable X-ray assembly during acquisition of X-ray data; and generating a plurality of X-ray images based on the received X-ray data and the determined amount of rotation and at least one of the rotational position of the rotatable X-ray assembly. A method for performing a breast procedure.

30. and further comprising: rotating the rotatable x-ray assembly to a particular position corresponding to a particular x-ray image previously generated based on information received from the encoder assembly during acquisition of the particular x-ray image and based on a current rotational position determined from the information received from the encoder assembly.

30. A method of performing a breast procedure according to claim 29.

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