Method and system for tungsten-based radiation shield for pre-patient collimator of imaging device

Abstract

Various methods and systems are provided for a radiation shielding element (302, 702, 802) having a single continuous shape formed from a first wall and a second wall positioned at a non-zero angle relative to the first wall, the second wall being connected to the first wall along a first axis, and the first wall and the second wall each being composed of a tungsten polymer blend, wherein the amount of tungsten is from 20% to 60% by volume relative to the polymer.

Description

Technical Field

[0001] Embodiments of the subject matter disclosed herein relate to radiation shielding elements, and in particular to methods of manufacturing tungsten-based radiation shielding elements for use with imaging devices via additive manufacturing. Background Art

[0002] Various types of electromagnetic radiation shielding have been developed for imaging applications and similar applications, such as X-ray fluorescence (XRF) equipment, which also uses electromagnetic radiation shielding to reduce the undesirable spread of radiation in the environment. Traditionally, such forms of shielding include the use of lead. Lead is a highly effective shielding material due to its high density (e.g., relatively high atomic mass and relatively small atomic radius), which absorbs and scatters various forms of electromagnetic radiation, including X-rays. With recent developments in the field of digital radiography, digital sensors that replace traditional photographic films are capable of producing X-ray images from lower levels of radiation emissions. However, lead lacks structural strength and rigidity, so that the shape of the lead-based shield may warp or shift over time, resulting in degradation of the shield's shielding capabilities.

[0003] Tungsten is another material that can be used to form radiation shielding elements. Tungsten can be mixed with polymers to form planar shielding elements, such as flat sheets formed by injection molding and / or extrusion of tungsten polymer blends to form radiation shielding elements. Conventional methods for forming radiation shielding elements (such as housings, frames, or other geometric shapes with 3D shapes) with geometric shapes more complex than planar sheets can include printing, stamping, or otherwise forming multiple parts of the radiation shielding element, and then performing post-processing steps such as gluing, welding, or otherwise fastening these parts together to form the radiation shielding element. Post-processing may additionally include cutting, stamping, or otherwise removing material from the radiation shielding element to form a through hole. However, this may produce a portion on the radiation shielding element through which radiation may leak. In addition, the process may consume unnecessary time and resources. Summary of the invention

[0004] A radiation shielding element (e.g., a pre-patient collimator for an imaging device) is described herein, having a single continuous shape formed by a first wall and a second wall positioned at a non-zero angle relative to the first wall, the second wall being connected to the first wall along a first axis, and the first wall and the second wall are both composed of a blend of tungsten and a polymer, wherein the amount of tungsten is 20% to 60% by volume relative to the polymer. The radiation shielding element includes at least one of a through hole, a groove, an undercut, or a fin. The polymer is one of the following: polyamide (PA) 11, PA12, a thermoplastic such as thermoplastic polyurethane (TPU), acrylonitrile butadiene styrene (ABS), or an equivalent plastic.

[0005] A radiation shielding element for a pre-patient collimator can be formed via additive manufacturing. A method for manufacturing a radiation shielding element, including an example radiation shielding element for a pre-patient collimator of an imaging device, includes receiving data defining one or more parameters of the radiation shielding element, generating a digital model of the radiation shielding element from the one or more parameters, the digital model including a first wall and a second wall positioned at a non-zero angle relative to the first wall, the second wall being connected to the first wall along a first axis, defining an additive manufacturing tool path for forming the radiation shielding element into a single continuous shape according to the digital model, providing a molten compound to the additive manufacturing tool, the molten compound including a substantially pure volume of tungsten substantially uniformly distributed in a polymer mixture, wherein the amount of tungsten is 20% to 60% by volume relative to the polymer mixture, and then actuating the additive manufacturing tool to dispense the molten compound into a predetermined location according to the additive manufacturing tool path, wherein the predetermined location defines a single continuous geometry of the radiation shielding element, the geometry having a first wall and a second wall positioned at a non-zero angle relative to the first wall, the second wall being connected to the first wall along the first axis.

[0006] The formulation of the tungsten polymer blend (e.g., 20% to 60% tungsten by volume relative to the polymer) enables the material used to form the radiation shielding element to be selectively ductile. The tungsten polymer blend formed into pellets, filaments, powders, etc. can be heated to a molten state to increase the ductility of the tungsten polymer blend, and to enable complex geometric shapes to be formed by dispensing the molten tungsten polymer blend from an additive manufacturing tool. The formulation can further enable the tungsten polymer blend to be quickly (e.g., within 5 seconds) cooled to a non-molten solid state when dispensed by an additive manufacturing tool, wherein the solid tungsten polymer blend has a rigidity capable of constructing and maintaining the geometry of the radiation shielding element. The tungsten polymer blend has a rigidity between 4000 kg / m 3 With at least 12000kg / m 3 The density of the radiation shielding element is between , and the wall of the radiation shielding element has a thickness capable of shielding radiation, and its shielding performance is comparable to that provided by, for example, a radiation shielding element formed of lead or pure tungsten, while having lower cost, density, and being able to achieve more complex shapes. For example, the thickness can be 0.2 mm or 0.3 mm, with a maximum thickness of 5 mm. In some embodiments, the thickness can be 6 mm or greater. In addition, due to the low density of the tungsten polymer blend, the radiation shielding element can be lighter than radiation shielding elements formed of other materials (such as blends of tungsten and polymers with different volume percentages of tungsten) or formed of lead, which can simplify the imaging process in which one or more radiation shielding elements are added to / removed from the imaging device.

[0007] This summary introduces the concepts described in more detail in the detailed description. It should not be used to determine the essential features of the claimed subject matter, nor should it be used to limit the scope of the claimed subject matter. It should be understood that the above brief description is provided to introduce selected concepts further described in the detailed description in a simplified form. This is not meant to identify the key features or essential features of the claimed subject matter, the scope of which is uniquely defined by the claims following the detailed description. In addition, the claimed subject matter is not limited to a specific implementation that solves any shortcomings mentioned above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present disclosure will be better understood by reading the following description of non-limiting embodiments with reference to the accompanying drawings, in which:

[0009] Figure 1 A pictorial view showing an imaging device according to one embodiment;

[0010] Figure 2 A schematic block diagram showing an exemplary imaging device according to one embodiment;

[0011] Figure 3 Shown for Figure 1 a perspective view of a first example radiation shield element of an example imaging device;

[0012] Figure 4 Shown for Figure 1 a side view of a first example radiation shield element of an example imaging device;

[0013] Figure 5 A graph showing the attenuation coefficient of conventional radiation shielding materials;

[0014] Figure 6 A graph showing the attenuation coefficient of tungsten polymer blends wherein the amount of tungsten is 20% to 60% by volume relative to the polymer mixture;

[0015] Figure 7 Shown for Figure 1 a second example radiation shielding element of a pre-patient collimator of an example imaging device of;

[0016] Figure 8 Shown for Figure 1 a first perspective view of a third example radiation shield element of an example pre-patient collimator of an example imaging device of FIG.

[0017] Fig. 9 Shown for Figure 1 a second perspective view of a third example radiation shield element of an example pre-patient collimator of an example imaging device of FIG.

[0018] Fig.10 A method of forming a radiation shielding element via additive manufacturing is presented. DETAILED DESCRIPTION

[0019] Now refer to Figures 1 to 10 Embodiments of the present disclosure are described by way of example and relate to various embodiments of a radiation shielding element for an imaging device, the radiation shielding element having a single continuous shape formed by a first wall and a second wall positioned at a non-zero angle relative to the first wall, wherein the second wall is connected to the first wall along a first axis, and both the first wall and the second wall are composed of a blend of tungsten and a polymer, wherein the amount of tungsten relative to the polymer is 20% to 60% by volume. Figure 1 and Figure 2 An exemplary imaging device is presented that emits radiation and may have a radiation shielding element coupled thereto as described herein. Figure 3 to Figure 4 , Figure 7 as well as Figures 8 to 9 Example radiation shielding elements are shown that are formed from a tungsten polymer blend having 20% ​​to 60% tungsten by volume relative to the polymer and each having a single continuous shape. Figure 5 and Figure 6 Each includes a graph showing the radiation attenuation coefficient of coupons of varying thicknesses formed from conventional lead-based or tungsten-based materials or the tungsten-polymer blends described herein, respectively. Fig.10 A flow chart showing a method of forming a radiation shield element for an imaging device, such as the radiation shield elements described herein, via additive manufacturing.

[0020] Figure 1 An exemplary computed tomography (CT) system 100 configured for CT imaging is shown. Specifically, the CT system 100 is configured to image a subject 112 (such as a patient, an inanimate object, one or more manufactured parts) and / or a foreign object (such as a dental implant, a stent, and / or a contrast agent present in the body). In one embodiment, the CT system 100 includes a gantry 102, which in turn may also include at least one X-ray source 104 configured to project an X-ray radiation beam 106 (see Figure 2 ) for imaging a subject 112 lying on an examination table 114. Specifically, the x-ray source 104 is configured to project an x-ray radiation beam 106 toward a detector array 108 positioned on an opposite side of the gantry 102. Figure 1Only a single x-ray source 104 is depicted, but in some embodiments, multiple x-ray sources and detectors may be employed to project multiple x-ray radiation beams 106 to acquire projection data at different energy levels corresponding to the patient. In some embodiments, the x-ray source 104 may implement dual energy gem spectrum imaging (GSI) by rapid peak kilovolt voltage (kVp) switching. In some embodiments, the x-ray detector employed is a photon counting detector capable of distinguishing x-ray photons of different energies. In other embodiments, two sets of x-ray sources and detectors are used to generate dual energy projections, wherein one set of x-ray sources and detectors is set at a low kVp and the other set is set at a high kVp.

[0021] In certain embodiments, the CT system 100 further includes an image processor unit 110 configured to reconstruct an image of a target volume of the subject 112 using an iterative or analytical image reconstruction method. For example, the image processor unit 110 may use an analytical image reconstruction method such as filtered back projection (FBP) to reconstruct an image of the patient's target volume. As another example, the image processor unit 110 may use an iterative image reconstruction method (such as advanced statistical iterative reconstruction (ASIR), conjugate gradient (CG), maximum likelihood expectation maximization (MLEM), model-based iterative reconstruction (MBIR), etc.) to reconstruct an image of the target volume of the subject 112. As further described herein, in some examples, in addition to iterative image reconstruction methods, the image processor unit 110 may also use analytical image reconstruction methods (such as FBP).

[0022] In some CT imaging system configurations, an x-ray source projects a cone-shaped x-ray radiation beam that is collimated to lie in the XYZ plane of a Cartesian coordinate system and is often referred to as the "imaging plane". The x-ray radiation beam passes through an object being imaged, such as a patient or subject. The x-ray radiation beam impinges on an array of detector elements after being attenuated by the object. The intensity of the attenuated x-ray radiation beam received at the detector array depends on the attenuation of the radiation beam by the object. Each detector element of the array produces a separate electrical signal that is a measurement of the attenuation of the x-ray beam at the detector location. The attenuation measurements from all detector elements are collected individually to produce a transmit profile.

[0023] In some CT systems, a gantry is used to rotate the x-ray source and detector array around the object to be imaged in the imaging plane so that the angle at which the radiation beam intersects the object is constantly changing. A set of x-ray radiation attenuation measurements (e.g., projection data) from the detector array at one gantry angle is called a "view". A "scan" of an object includes a set of views made at different gantry angles or viewing angles during one rotation of the x-ray source and detector. It is conceivable that the benefits of the methods described herein are derived from medical imaging modalities other than CT, so as used herein, the term "view" is not limited to the use described above with respect to projection data from one gantry angle. The term "view" is used to mean a data acquisition whenever there are multiple data acquisitions from different angles (whether from CT, positron emission tomography (PET) or single photon emission CT (SPECT) acquisitions), and / or any other modality (including modalities yet to be developed) and their combination in fusion embodiments.

[0024] The projection data is processed to reconstruct an image corresponding to a two-dimensional slice acquired through the object, or in some examples where the projection data includes multiple views or scans, an image corresponding to a three-dimensional rendering of the object. A method for reconstructing an image from a set of projection data is known in the art as a filtered back projection technique. Transmission and emission tomography reconstruction techniques also include statistical iterative methods such as maximum likelihood expectation maximization (MLEM) and ordered subset expectation reconstruction techniques and iterative reconstruction techniques. The method converts the attenuation measurements from the scan into integers known as "CT numbers" or "Houyn units", which are used to control the brightness of corresponding pixels on a display device.

[0025] To reduce the total scan time, a "helical" scan can be performed. To perform a "helical" scan, the patient is moved while data for a specified number of slices is acquired. Such systems generate a single spiral from a cone beam helical scan. The spiral mapped out by the cone beam produces projection data from which an image in each specified slice can be reconstructed.

[0026] As used herein, the phrase "reconstructing an image" is not intended to exclude embodiments in which data representing an image is generated without generating a visible image. Thus, as used herein, the term "image" broadly refers to both a visible image and data representing a visible image. However, many embodiments generate (or are configured to generate) at least one visible image.

[0027] Figure 2 An example similar to Figure 1 1. An exemplary imaging system 200 of the CT system 100 of FIG. According to aspects of the present disclosure, the imaging system 200 is configured to image a subject 204 (eg, Figure 1In one embodiment, the imaging system 200 includes a detector array 108 (see Figure 1 ). The detector array 108 also includes a plurality of detector elements 202 that together sense the X-ray radiation beam 106 that passes through a subject 204 (such as a patient) (see Figure 2 ) to collect corresponding projection data. Therefore, in one embodiment, the detector array 108 is manufactured in a multi-slice configuration including multiple rows of units or detector elements 202. In such a configuration, another row or multiple rows of detector elements 202 are arranged in a parallel configuration to collect projection data.

[0028] In certain embodiments, the imaging system 200 is configured to traverse different angular positions around the subject 204 to acquire desired projection data. Thus, the gantry 102 and components mounted thereon can be configured to rotate about the rotation center 206 for acquiring, for example, projection data at different energy levels. Alternatively, in embodiments where the projection angle relative to the subject 204 changes over time, the mounted components can be configured to move along a generally curved line rather than along a segment of a circle.

[0029] As the x-ray source 104 and the detector array 108 rotate, the detector array 108 collects data of the attenuated x-ray beam. The data collected by the detector array 108 then undergoes pre-processing and calibration to condition the data to represent the line integral of the attenuation coefficient of the scanned subject 204. The processed data is often referred to as a projection.

[0030] In some examples, individual detectors or detector elements 202 in the detector array 108 may include photon counting detectors that register interactions of individual photons into one or more energy bins. It should be appreciated that the methods described herein may also be implemented using energy integrating detectors.

[0031] The acquired projection data sets may be used for base material decomposition (BMD). During BMD, the measured projections are converted into a set of material density projections. The material density projections may be reconstructed to form a pair or set of material density maps or images for each corresponding base material (such as bone, soft tissue, and / or contrast agent maps). The density maps or images may then be correlated to form a volume rendering of the base material (e.g., bone, soft tissue, and / or contrast agent) in the imaging volume.

[0032] Once reconstructed, the base material image produced by the imaging system 200 shows the internal features of the subject 204 represented by the density of the two base materials. The density image can be displayed to show these features. In traditional methods of diagnosing medical conditions (such as disease states), and more generally diagnosing medical events, a radiologist or physician will consider a hard copy or display of a density image to discern characteristic features of interest. Such features can include lesions, size and shape of specific anatomical structures or organs, as well as other features that should be discernible in the image based on the skill and knowledge of the individual practitioner.

[0033] In one embodiment, the imaging system 200 includes a control mechanism 208 to control movement of components, such as rotation of the gantry 102 and operation of the x-ray source 104. In certain embodiments, the control mechanism 208 also includes an x-ray controller 210 configured to provide power and timing signals to the x-ray source 104. Additionally, the control mechanism 208 includes a gantry motor controller 212 configured to control the rotational speed and / or position of the gantry 102 based on imaging requirements.

[0034] In certain embodiments, the control mechanism 208 also includes a data acquisition system (DAS) 214 that is configured to sample analog data received from the detector elements 202 and convert the analog data into digital signals for subsequent processing. The DAS 214 may also be configured to selectively aggregate analog data from a subset of the detector elements 202 into a so-called macro detector, as further described herein. The data sampled and digitized by the DAS 214 is sent to a computer or computing device 216. In one example, the computing device 216 stores the data in a storage device 218. For example, the storage device 218 may include a hard drive, a floppy disk drive, a compact disk read / write (CD-R / W) drive, a digital versatile disk (DVD) drive, a flash drive, and / or a solid-state storage drive.

[0035] In addition, the computing device 216 provides commands and parameters to one or more of the DAS 214, the x-ray controller 210, and the gantry motor controller 212 to control system operations, such as data acquisition and / or processing. In certain embodiments, the computing device 216 controls system operations based on operator input. The computing device 216 receives operator input, which includes, for example, commands and / or scan parameters, via an operator console 220 operatively coupled to the computing device 216. The operator console 220 may include a keyboard (not shown) or a touch screen to allow an operator to specify commands and / or scan parameters.

[0036] Although Figure 2Only one operator console 220 is shown, but more than one operator console may be coupled to the imaging system 200, for example, to input or output system parameters, request exams, plot data, and / or view images. Additionally, in certain embodiments, the imaging system 200 may be coupled to multiple displays, printers, workstations, and / or the like located locally or remotely, for example, within an institution or hospital or at an entirely different location, via one or more configurable wired and / or wireless networks (such as the Internet and / or a virtual private network, a wireless telephone network, a wireless local area network, a wired local area network, a wireless wide area network, a wired wide area network, etc.).

[0037] In one embodiment, for example, the imaging system 200 includes or is coupled to a picture archiving and communication system (PACS) 224. In one exemplary implementation, the PACS 224 is further coupled to a remote system (such as a radiology department information system, a hospital information system) and / or to an internal or external network (not shown) to allow operators at different locations to supply commands and parameters and / or gain access to image data.

[0038] The computing device 216 uses operator-provided and / or system-defined commands and parameters to operate a table motor controller 226, which in turn can control the table 114, which can be a motorized table. Specifically, the table motor controller 226 can move the table 114 to properly position the subject 204 in the gantry 102 to acquire projection data corresponding to a target volume of the subject 204.

[0039] As previously described, the DAS 214 samples and digitizes the projection data acquired by the detector elements 202. Subsequently, the image reconstructor 230 uses the sampled and digitized x-ray data to perform high-speed reconstruction. Figure 2 The image reconstructor 230 is illustrated as a separate entity, but in certain embodiments, the image reconstructor 230 may form part of the computing device 216. Alternatively, the image reconstructor 230 may not be present in the imaging system 200, and instead the computing device 216 may perform one or more functions of the image reconstructor 230. In addition, the image reconstructor 230 may be located locally or remotely, and may be operably connected to the imaging system 200 using a wired network or a wireless network. In particular, an exemplary embodiment may use computing resources in a "cloud" network cluster for the image reconstructor 230.

[0040] In one embodiment, the image reconstructor 230 stores the reconstructed image in the storage device 218. Alternatively, the image reconstructor 230 may send the reconstructed image to the computing device 216 to generate usable patient information for diagnosis and evaluation. In certain embodiments, the computing device 216 may transmit the reconstructed image and / or the patient information to a display or display device 232 that is communicatively coupled to the computing device 216 and / or the image reconstructor 230. In some embodiments, the reconstructed image may be transmitted from the computing device 216 or the image reconstructor 230 to the storage device 218 for short-term or long-term storage.

[0041] The radiation shielding element can be selectively coupled to the imaging device and / or its user input device via one or more screws, bolts, clips, latches, etc. For example, the radiation shielding device can be coupled to the examination table 114 to shield areas of the subject 112 that are not to be imaged from radiation. Additionally or alternatively, the radiation shielding element can be coupled to the operator console 220. The radiation shielding element can be further coupled to additional elements or areas of the environment in which the radiation is used, such as to selectively shield areas of the environment from radiation. Since different environments in which radiation is used may include the same or different devices formed by the same or different manufacturers, these devices are arranged in different locations around rooms of different shapes and sizes, and these devices are used by different operators in different ways and at different frequencies, radiation shielding elements of different sizes and shapes may be required in different environments. Ideally, the radiation shielding element has substantially the same shielding capabilities as lead or other blends of tungsten and polymers, while having the desired size and shape. An example radiation shielding element formed of a "tungsten polymer blend" is described herein, wherein the amount of tungsten is 20% to 60% by volume relative to the polymer. The tungsten polymer blend described herein is ductile and can be stored in the form of a powder, pellets, reels, etc. The ductility of the tungsten polymer blend (e.g., rapid cooling to a solid state after heating to a molten state without the use of an external tool for cooling) and the rigidity of the solid tungsten polymer blend enable the formation of radiation shielding elements with continuous (e.g., seamless) geometries. In addition, the tungsten polymer blend complies with the Restriction of Hazardous Substances (RoHS) directive. The tungsten polymer blend is recyclable, thereby reducing the carbon footprint in the manufacturing process. Compared with radiation shielding elements formed from other materials (such as lead) or radiation shielding elements formed using a method having a pre-treatment step and / or a post-treatment step, the method for forming a radiation shielding element from a tungsten polymer blend described herein can have multiple advantages. For example, the method for forming a radiation shielding element described herein can produce radiation shielding elements with continuous, complex geometries that can be adjusted in proportion to the desired size and shape. For example, the method for forming a radiation shielding element described herein can reduce the amount of hazardous waste generated during the manufacturing process. As described herein, a wall connected to another wall along an axis should be understood as seamlessly joined. For example, the first wall and the second wall are formed of a tungsten polymer blend, and the second wall is formed as a continuation of the first wall. In addition, the radiation shielding element may include a through hole extending from a first side of the wall through the thickness of the wall to a second side of the wall. When the radiation shielding element is formed using a method other than additive manufacturing, the through hole can be formed during post-processing and / or complex stamping.

[0042] exist Figure 3A first embodiment of a radiation shielding element 302 for use in an imaging device is shown in a first perspective view 300 of FIG. Figure 3 to Figure 4 400 . An axis system 399 is provided for reference. In one example, the y-axis may be a vertical axis (e.g., parallel to the gravity axis), the x-axis may be a lateral axis (e.g., a horizontal axis), and the z-axis may be a longitudinal axis. However, in other examples, the axes may have other orientations. When perpendicular to the view and extending toward the view, the axis may be represented as a solid circle. Similarly, when perpendicular to the view and extending away from the view, the axis may be represented by a hollow circle, such as in the second perspective view 400.

[0043] The radiation shielding element 302 is formed of a blend of tungsten and a polymer, wherein the amount of tungsten is 20% to 60% by volume relative to the polymer. The polymer may be one of the following: polyamide (PA) 11, PA12, a thermoplastic such as thermoplastic polyurethane (TPU), acrylonitrile butadiene styrene (ABS), or an equivalent plastic or polyamide. The radiation shielding element 302 has a single continuous shape formed by a first wall 304 and a second wall 306, wherein the second wall is positioned at a non-zero angle relative to the first wall 304 and is connected to the first wall 304 along a first axis 308. Thus, the first wall 304 and the second wall 306 are seamlessly joined. Each of the first wall 304 and the second wall 306 is planar, and the radiation shielding element 302 includes at least one of an undercut, a groove, a through hole, or a fin. The radiation shielding element 302 may be formed by, for example, Fig.10 1000. Thus, during the formation of the first wall 304 and the second wall 306, features such as undercuts, grooves, through holes, and / or fins may be formed in the radiation shield element 302. This eliminates the need to create these features in a radiation shield element formed using a method other than additive manufacturing using a post-processing step (e.g., after forming the radiation shield element 302), such as stamping or machining.

[0044] The radiation shield element 302 may be characterized by a plurality of through holes of various sizes and shapes. The through holes may be used to mount the radiation shield element 302 to an imaging device and / or a user interface, such as a Figure 1 to Figure 2 As described. In some embodiments, for example, cables connecting elements of the imaging device to each other and / or to other medical devices can pass through the through holes. The radiation shielding element 302 includes circular through holes of a small size 310, a medium size 312, and a large size 314. Other example radiation shielding elements may include circular through holes that are larger than the large size 314, smaller than the small size 310, and any size in between. The first wall 304 also includes a rectangular through hole 316. The rectangular through hole 316 extends a through hole length 318. The through hole length 318 is less than the wall length 320 of the first wall 304, and greater than half of the wall length 320. In Figure 3 In the illustrated embodiment, the first wall 304 may also include a plurality of circular through holes along the through hole length 318 on each side of the rectangular through hole 316. The composition of the tungsten polymer blend provides the first wall 304 with structural rigidity, which enables the first wall 304 to have a plurality of through holes distributed over the surface area of ​​the first wall 304 while maintaining the planar integrity of the first wall 304. For example, as described herein, the first wall 304 has multiple through holes that extend over a large surface area (e.g., a rectangular through hole 316 extending a distance greater than half of the wall length 320 of the first wall 304) and are supported by small areas of the first wall 304 (e.g., a first width 322 of the first wall 304 between the medium-sized circular through hole 324 and the rectangular through hole 316, and a second width 326 of the first wall 304 between the small-sized circular through hole 328 and the first edge 330 of the first wall 304), and the rigidity of the first wall 304 provided by the composition of the tungsten polymer blend can prevent multiple areas of the first wall 304 from sagging, warping, or otherwise deforming out of a plane (e.g., an XZ plane relative to the axis system 399).

[0045] The second wall 306 of the radiation shield element 302 also includes a plurality of circular through holes of varying sizes. The second wall 306 has a rectangular shape with an extension 332 extending from a second edge 334, the extension 332 having a curved notch 336. As described above, the composition of the tungsten polymer blend enables this geometry to be formed during the formation of the second wall 306 and is structurally stable (e.g., the arms 338 of the extension 332 do not sag, fold, or otherwise deform toward the curved notch 336). Figure 4 The geometry enabled by the rigidity of the radiation shield element 302 provided by the composition of the tungsten polymer blend is further described.

[0046] Figure 4 A second perspective view 400 of a radiation shielding element 302 for use in an imaging device is shown. The rigidity of the tungsten polymer blend enables the second wall 306 to be formed at a non-zero angle 402 relative to the first wall 304. For example, the radiation shielding element 302 has a second wall 306 positioned at a 90 degree angle relative to the first wall 304, where the non-zero angle 402 is a 90 degree angle. In other embodiments, the non-zero angle 402 can be greater than 0 degrees and less than 90 degrees, or greater than 90 degrees and less than 180 degrees. The composition of the tungsten polymer blend (e.g., the volume percentage of tungsten relative to the polymer) enables the tungsten polymer blend to be quickly cooled (e.g., within 5 seconds) from a molten state to a solid state after being dispensed from an additive manufacturing tool, as described with respect to Fig.10Further described. In the solid state, the tungsten polymer blend is rigid enough to support structures, such as the first wall 304 and the second wall 306 of the radiation shield element 302, positioned at a non-zero angle relative to each other.

[0047] As about Figures 5 and 6 Further described, tungsten polymer blends are capable of attenuating (e.g., shielding) radiation over a wider range of thicknesses than conventional radiation shielding elements. Variable material densities can be achieved for any desired attenuation, and any desired geometry can be formed through additive manufacturing using tungsten polymer blends because tungsten polymer blends can be transformed from a solid state to a liquid state through exposure to heat.

[0048] Figure 5 A graph 500 showing the attenuation coefficient of lead is shown. The thickness of the material sample block is shown in millimeters (mm) along the x-axis. The data for the graph 500 is collected by exposing the sample blocks of each thickness (e.g., 1.0 mm, 1.5 mm, 1.75 mm) to an X-ray beam of equal intensity, and then measuring the radiation exposure on the side of the sample block opposite to the X-ray beam source (e.g., so that the sample block is located between the measurement tool and the X-ray beam source). The exposure is displayed on the Y-axis in units of reciprocal centimeters (Rcm). Line 502 of the graph 500 is an exponential function that can be used to solve for the attenuation coefficient. The attenuation coefficient shows the ease with which a volume (e.g., a sample block) can be penetrated by an X-ray beam.

[0049] When no coupon is positioned between the measurement tool and the X-ray beam (e.g., at 0.0 mm), the exposure is approximately 91 Rcm. Using the exposure data collected for 0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm thick coupons, an exponential decay function of the intensity can be generated, where the slope is the decay coefficient. Figure 5 In the embodiment of FIG. 1 , the attenuation coefficient of conventional lead is about 3.9.

[0050] Go to Figure 6 , the graph 600 shown shows the attenuation coefficient of the tungsten polymer blends described herein, wherein the tungsten is 20% to 60% by volume relative to the polymer. Figure 5 In graph 500, the thickness of the material sample block is shown in mm along the X-axis and the exposure is shown in Rcm on the Y-axis. The data for graph 600 is collected by exposing samples of each thickness (e.g., 0.5 mm, 3.5 mm, and thicknesses in between) to an X-ray beam of the same intensity and then measuring the radiation exposure on the side of the sample block opposite the X-ray beam source.

[0051] When no coupon is positioned between the measurement tool and the X-ray beam (e.g., at 0.0 mm), the exposure is approximately 92 Rcm. Using the exposure data collected for 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, and 3.5 mm thick coupons, an exponential decay function of intensity (shown by line 602) can be generated, where the slope is the decay coefficient. Figure 6 In an embodiment, the tungsten polymer blends described herein having 20% ​​to 60% tungsten by volume have an attenuation coefficient of about 2.2.

[0052] A large attenuation coefficient indicates that the beam becomes "attenuated" as it passes through a given medium (e.g., a coupon), while a small value indicates that the medium has little effect on shielding. The attenuation coefficient measures the exponential decay of intensity, i.e., when energy passes through a unit (e.g., 1 meter) thickness of material, the original intensity is reduced to 1 / e of its original intensity, so the attenuation coefficient is 1m -1 This means that after passing through 1 meter, the radiation will be reduced to 1 / e, while for a factor of 2m -1 The radiation amount will be reduced to 1 / e square, that is, 1 / e 2 .

[0053] As shown in graph 500, using a sample block with a thickness of 1.8 mm and an attenuation coefficient of 3.866 formed by lead, the 91Rcm exposure is reduced to 0.17Rcm. The sample block formed by lead has a half-value layer thickness of 0.179 mm (e.g., a 0.179 mm sample block reduces exposure by half from 91Rcm). Graph 600 shows the X-ray attenuation capability of tungsten polymer blends described herein, wherein the half-value layer thickness is 0.311 mm (e.g., a 0.311 mm thick sample block reduces exposure by half from 92Rcm). Using a sample block with a thickness of 3.25 mm and an attenuation coefficient of 2.223 formed by a tungsten polymer blend, the 92Rcm exposure is reduced to 0.186Rcm. An embodiment of a tungsten polymer blend for capturing the data of graph 600 can have a lower amount of tungsten by volume relative to the polymer, such as 20%. Under this tungsten amount by volume, the attenuation capability of the tungsten polymer blend differs from the lead attenuation coefficient by less than two units. By increasing the amount of tungsten relative to the polymer by volume, the attenuation capability of the tungsten polymer blend can be further increased (e.g., attenuating / shielding an increased amount of radiation at a given thickness). Thus, by adjusting the percentage of tungsten, the attenuation coefficient of the tungsten polymer blend can be made similar to or greater than that of conventional lead.

[0054] Go to Figure 7 , showing an imaging device (e.g., Figure 1 A perspective view 700 of a second embodiment of a radiation shielding element 702 for a pre-patient collimator of an imaging device (e.g., an imaging device of the invention). Figure 7799 is provided for reference. In one example, the y-axis may be a vertical axis (e.g., parallel to the gravity axis), the x-axis may be a lateral axis (e.g., a horizontal axis), and the z-axis may be a longitudinal axis. However, in other examples, the axes may have other orientations. The radiation shield element 702 has a single continuous shape formed by a first wall 704 and a second wall 706, wherein the second wall is positioned at a non-zero angle 708 relative to the first wall 704 and is connected to the first wall 704 along a first axis 710. In addition, the radiation shield element 702 includes a third wall 712 and a fourth wall 716, wherein the third wall is connected to the first wall 704 along a second axis 714 of the first wall 704 that is different from the first axis 710, and the fourth wall is connected to the second wall 706 along a third axis 718 (e.g., a third axis of the second wall 706 that is opposite to the first axis 710) and connected to the third wall 712 along a fourth axis 720 (e.g., a fourth axis of the third wall 712 that is opposite to the second axis 714). The radiation shield element 702 also includes a fifth wall 722 connected to each of the first wall 704, the second wall 706, the third wall 712, and the fourth wall 716. Each of the first wall 704, the second wall 706, the third wall 712, and the fourth wall 716 is planar, wherein the second wall 706 and the third wall 712 are rectangular, and the first wall 704 and the fourth wall 716 are trapezoidal. For example, relative to the axis system 799, the first wall 704 and the fourth wall 716 are planar and parallel in the XZ plane. The fifth wall 722 is rectangular and has a curved extension 734 extending out of a plane (e.g., a YX plane relative to the axis system 799), as further described herein.

[0055] The radiation shielding element 702 is formed of a tungsten polymer blend in which the amount of tungsten is 20% to 60% by volume relative to the polymer. As described above, the polymer can be one of the following: PA11, PA12, TPU, ABS, or an equivalent plastic. The rigidity of the tungsten polymer blend when in solid form enables the second wall 706 to be formed at a non-zero angle 708 relative to the first wall 704. For example, the radiation shielding element 702 has a second wall 706 positioned at a 90-degree angle relative to the first wall 704. In other embodiments, the non-zero angle 708 can be greater than 0 degrees and less than 90 degrees, or greater than 90 degrees and less than 180 degrees. The composition of the tungsten polymer blend (e.g., the volume percentage of tungsten relative to the polymer) enables the tungsten polymer blend to be quickly cooled (e.g., within 5 seconds) from the molten state to the solid state after being dispensed from the additive manufacturing tool. Fig.10 Further described. In the solid state, the tungsten polymer blend is rigid enough to support structures, such as the first wall 704 and the second wall 706 of the radiation shield element 702, positioned at a non-zero angle relative to each other.

[0056] The rigidity of the radiation shield element 702 provided by the solid tungsten polymer blend (e.g., without applying heat thereto) further enables the formation of the third wall 712 and the fourth wall 716. The fourth wall 716 is spaced apart from the first wall 704 by the height 724 of the second wall 706 and the third wall 712. The second wall 706 and the third wall 712 are spaced apart by the length 726 of the first wall 704 and the fourth wall 716. The second wall 706 and the third wall 712 extend between a pair of non-parallel sides of the trapezoid (e.g., between a first side 728 of each of the first wall 704 and the fourth wall 716, and between a second side 730 of each of the first wall 704 and the fourth wall 716). The third wall 712 is formed at a non-zero angle relative to the first wall 704 and the fourth wall 716, and the fourth wall 716 is parallel to the first wall 704 and formed at a non-zero angle relative to the second wall 706. Figure 7 In an embodiment, each of the non-zero angles between the walls is equal to 90 degrees.

[0057] The first wall 704 and the fourth wall 716 may be as Figure 7 The first wall 704 and the fourth wall 716 are spaced apart as shown, and will not warp, sag, or otherwise deform out of plane (e.g., relative to the XZ plane of the axis system 799) without support from support elements other than the second wall 706 and the third wall 712, because the structural integrity of the first wall 704 and the second wall 706 is provided by the rigidity of the blend of tungsten and polymer when in the solid state. In addition, each of the first wall 704 and the fourth wall 716 includes a circular through hole 732. In Figure 7 In an embodiment of the present invention, the circular through holes 732 of each of the first wall 704 and the fourth wall 716 are aligned along the Y axis. In some examples, wires or other connectors of an imaging device (e.g., CT system 100) can pass through the circular through holes 732. In other examples, screws or other coupling devices can pass through one or both of the circular through holes 732 to couple the radiation shielding element 702 to an imaging device or other radiation emitting source.

[0058] The rectangular shape of the fifth wall 722 is planar relative to the YX plane of the axis system 799, and the curved extension 734 of the fifth wall 722 extends out of the YX plane in the direction of the Z axis. The fifth wall 722 (including the curved extension 734) is connected to each of the first wall 704, the second wall 706, the third wall 712 and the fourth wall 716. The fifth wall 722 further extends the wall length 736 so that it is longer than the edge length 738 of the first wall 704 and the fourth wall 716 along the top edge 740. The curved extension 734 is approximately positioned at the center of the wall length 736 and extends into the fourth wall 716 in the Z axis direction. The curved extension 734 is connected to both the fourth wall 716 and the fifth wall 722, so that the radiation shielding element 702 has no seam or gap between the fifth wall 722 and the fourth wall 716. As described with respect to Fig.10 The method further describes that the radiation shielding element 702 can be formed via additive manufacturing, wherein pellets, powders, filaments wound on a reel, or other solid blends of tungsten and polymers are heated to become molten, and then the molten blend is extruded from an additive manufacturing tool into a predetermined geometric shape, and the molten blend is quickly (e.g., within 5 seconds after extrusion) cooled to a solid state. The formation of the curved extension 734 is included in the formation of the fifth wall 722 and the formation of the fourth wall 716 (optionally, in the embodiment where the curved extension 734 extends into the first wall 704, it is included in the formation of the first wall 704). A conventional method for forming a radiation shielding element may include forming the fourth wall 716 into a trapezoid, forming the fifth wall 722 into one or more rectangular pieces, forming a curved extension piece (e.g., the geometry of the curved extension 734 as an independent piece, separate from the fifth wall 722), and then cutting out the shape of the curved extension piece in the fourth wall 716. The fourth wall 716, the fifth wall 722, and the curved extension piece can be connected by gluing, welding, or other connection methods. Using additive manufacturing and the tungsten polymer blends described herein, the radiation shielding element can be formed into a single continuous seamless component having a geometry including linear elements and curved elements, as well as linear through holes and / or curved through holes in planar elements or curved elements. Similar to the circular through holes 732 of the first wall 704 and the fourth wall 716, the curved extension 734 of the fifth wall 722 can serve as a channel through which one or more wires or other connecting elements of a user input device and / or an imaging device pass. For example, the radiation shielding element 702 can be positioned so that the rectangular shape of the fifth wall 722 is positioned in coplanar contact with the user input device, and the curved extension 734 provides a gap between the user input device and the radiation shielding element 702.

[0059] Go to Figures 8 to 9 , a third embodiment of a radiation shielding element 802 is shown. Figure 8 and Fig. 9The example radiation shielding elements may also be used with a pre-patient collimator of an imaging device. Figure 8 A first perspective view 800 showing a radiation shield element 802, Fig. 9 A second perspective view 900 of the radiation shielding element is shown. Figures 8 to 9 Axis system 899 is provided for reference and is also described herein. Figures 8 to 9 In one example, the y-axis can be a vertical axis (eg, parallel to the gravity axis), the x-axis can be a lateral axis (eg, a horizontal axis), and the z-axis can be a longitudinal axis. However, in other examples, the axes can have other orientations.

[0060] The radiation shield 802 is a single continuous shape formed by a first wall 804 and a second wall 806 positioned at a non-zero angle 808 relative to the first wall 804, the second wall 806 being connected to the first wall 804 along a first axis 810. In addition, the radiation shield 802 includes a third wall 812 and a fourth wall 816, wherein the third wall is connected to the first wall 804 along a second axis 814 of the first wall 804 that is different from the first axis 810, and the fourth wall is connected to the second wall 806 along a third axis 818 (e.g., a third axis of the second wall 806 that is opposite to the first axis 810) and connected to the third wall 812 along a fourth axis 820 (e.g., a fourth axis of the third wall 812 that is opposite to the second axis 814). The radiation shield 802 also includes a fifth wall 822 connected to each of the first wall 804, the second wall 806, the third wall 812, and the fourth wall 816. Each of the first wall 804, the second wall 806, the third wall 812, and the fourth wall 816 is planar. The second wall 806 and the third wall 812 are rectangular, and the first wall 804 and the fourth wall 816 are generally trapezoidal. The fifth wall 822 is rectangular and has a curved extension that extends out of a plane (e.g., a YX plane relative to the axis system 899), as further described herein.

[0061] The radiation shielding element 802 is formed of a tungsten polymer blend of tungsten and a polymer, wherein the amount of tungsten is 20% to 60% by volume relative to the polymer. As described above, the polymer can be one of the following: PA11, PA12, TPU, ABS, or an equivalent plastic. The rigidity of the tungsten polymer blend when in solid form enables the second wall 806 to be formed at a non-zero angle 808 relative to the first wall 804. For example, the radiation shielding element 802 has a second wall 806 positioned at a 90-degree angle relative to the first wall 804. In other embodiments, the non-zero angle 808 can be greater than 0 degrees and less than 90 degrees, or greater than 90 degrees and less than 180 degrees. The composition of the tungsten polymer blend (e.g., the volume percentage of tungsten relative to the polymer) enables the tungsten polymer blend to be quickly (e.g., within 5 seconds) cooled from the molten state to the solid state after being dispensed from the additive manufacturing tool. Fig.10 In the solid state, the tungsten polymer blend is sufficiently rigid (eg, has tensile and compressive strength) to support structures such as the first wall 804 and the second wall 806 of the radiation shield element 802 that are positioned at a non-zero angle relative to each other.

[0062] As mentioned above about Figure 3 , Figure 4 and Figure 8 As described, the rigidity of the radiation shield element provided by the solid tungsten polymer blend (e.g., without applying heat thereto) enables the formation of the third wall 812 and the fourth wall 816. The fourth wall 816 is spaced apart from the first wall 804 by the height 824 of the second wall 806 and the third wall 812. The second wall 806 and the third wall 812 are spaced apart by a first length 826 of the first wall 804 and the fourth wall 816 on the first side 866 of the radiation shield element 802. The second wall 806 and the third wall 812 are further spaced apart by a second length 838 at a second side 868 of the radiation shield element 802 opposite the first side 866. The first length 826 and the second length 838 are shown for illustrative purposes, and the dimensions of the first wall 804 and the fourth wall 816 may be the same or different. For example, the first length 826 of the first wall 804 can be greater than the first length 826 of the fourth wall 816, and therefore, each of the second wall 806 and the third wall 812 can be positioned at a non-zero angle (e.g., non-zero angle 808) less than 90 degrees relative to the first wall 804. The second wall 806 and the third wall 812 extend between a pair of non-parallel sides of the trapezoid (e.g., between the third side 828 of each of the first wall 804 and the fourth wall 816, and between the fourth side 830 of each of the first wall 804 and the fourth wall 816). The third wall 812 is formed at a non-zero angle relative to the first wall 804 and the fourth wall 816, and the fourth wall 816 is parallel to the first wall 804 and formed at a non-zero angle relative to the second wall 806. Figure 8 In an embodiment, each of the non-zero angles between the walls is equal to 90 degrees.

[0063] In addition, the rigidity of the radiation shielding element provided by the solid tungsten polymer blend enables the formation of extensions from one or more of the first wall 804, the second wall 806, the third wall 812, the fourth wall 816, and the fifth wall 822. The first wall 804 has a generally trapezoidal shape that is planar and parallel to the fourth wall 816, and also includes a planar extension 842. For illustrative purposes, a dashed line 844 is included to show the area of ​​the planar extension 842, but does not indicate a seam or other feature of the radiation shielding element 802. Relative to the axis system 899, the first wall 804 and the fourth wall 816 are planar and parallel in the XZ plane. The trapezoidal shapes of the first wall 804 and the fourth wall 816 each have a first width 846, and the second width 848 of the planar extension 842 further extends the total width of the first wall 804 to be greater than the first width 846 of the fourth wall 816. The planar extension 842 has a first edge 850 that forms an approximately 90 degree angle with the bottom edge of the first wall 804 (e.g., along dashed line 844), and also has a second edge 852 that forms a second non-zero angle (e.g., less than 180 degrees and greater than 90 degrees) with the bottom edge of the first wall 804. The tab extension 854 is connected to the planar extension 842 of the first wall 804 at a third non-zero angle 856 (e.g., 90 degrees) and is connected to the second wall 806 at a fourth non-zero angle 858 (e.g., less than 180 degrees and greater than 90 degrees).

[0064] As this article about Figures 3 to 8 As described above, the tungsten polymer blend can have a rigidity in the solid state that enables it to form a structurally stable geometric shape. Figure 8 and Fig. 9 As shown, the fin extension 854 and the planar extension 842 are coupled at a third non-zero angle 856, and are each further coupled along an additional axis to other elements of the radiation shield element 802. The rigidity of the solid tungsten and polymer blend enables the fin extension 854 and the planar extension 842 to be structurally stable (e.g., not bend / bend down out of plane) in the respective geometries of the extensions.

[0065] The first wall 804 and the fourth wall 816 may be as Figure 8 and Fig. 9The first wall 804 and the second wall 806 are spaced apart as shown, and will not warp, sag, or otherwise deform out of plane (e.g., relative to the XZ plane of the axis system 899) without support from support elements other than the second wall 806 and the third wall 812, because the structural integrity of the first wall 804 and the second wall 806 is provided by the rigidity of the blend of tungsten and polymer when in the solid state. In addition, each of the first wall 804 and the fourth wall 816 includes a circular through hole 832. In Figure 8 In an embodiment, the circular through holes 832 of each of the first wall 804 and the fourth wall 816 are aligned along the Y axis. In some examples, wires or other connectors of an imaging device (e.g., CT system 100) can pass through the circular through holes 832. In other examples, screws or other coupling devices can pass through one or both of the circular through holes 832 to couple the radiation shielding element 802 to an imaging device or other radiation emitting source.

[0066] The rectangular shape of the fifth wall 822 is planar relative to the YX plane of the axis system 899, and the curved extension 834 of the fifth wall 822 extends out of the YX plane in the direction of the Z axis. The fifth wall 822 (including the curved extension 834) is connected to each of the first wall 804, the second wall 806, the third wall 812, and the fourth wall 816. Fig. 9As shown, the first width 846 of the trapezoidal shape of the first wall 804 and the fourth wall 816 and the second length 860 of each of the second wall 806 and the third wall 812 extend through the rectangular opening 862 of the fifth wall 822. The fifth wall 822 further extends the wall length 836 to be longer than the second length 838 of the first wall 804 and the fourth wall 816 along the top edge 840. The curved extension 834 is positioned approximately at the center of the wall length 836 and extends into the fourth wall 816 in the Z-axis direction. The curved extension 834 is connected to both the fourth wall 816 and the fifth wall 822, so that the radiation shield element 802 has no seam or gap between the fifth wall 822 and the fourth wall 816. In addition, the first wall 804 and the fourth wall 816 include a second pair of circular through holes 864, which are vertically aligned with each other (e.g., along the Y-axis relative to the axis system 899) and vertically aligned with the concave side of the curved extension 834. Similar to the circular through holes 864 of the first wall 804 and the fourth wall 816, the curved extension 834 and the second pair of circular through holes 864 of the fifth wall 822 can provide a passage through which one or more wires or other coupling elements of the user input device and / or the imaging device pass. For example, the radiation shielding element 802 can be positioned so that the rectangular shape of the fifth wall 822 is positioned in coplanar contact with the user input device, and the curved extension 834 provides a gap between the user input device and the radiation shielding element 802. Additionally or alternatively, the curved extension 834 and the second pair of circular through holes 864 can be used to couple the radiation shielding element 802 to an imaging device or other radiation emitting source. For example, a screw or other coupling device can pass through the curved extension 834 and the second pair of circular through holes 864 to couple the radiation shielding element 802 to an imaging device (e.g., a CT system 100) or other radiation emitting source.

[0067] As about Fig.10 The method further describes that the radiation shielding element 802 to be used with the imaging device can be formed via additive manufacturing, wherein pellets, powders, filaments wound on a reel, or other solid blends of tungsten and a polymer are heated to become molten, and then the molten blend is extruded from an additive manufacturing tool into a predetermined geometry, and the molten blend is quickly (e.g., within 5 seconds after extrusion) cooled to a solid state. In some embodiments, the additive manufacturing method can include dispensing a molten tungsten and polymer blend along an additive manufacturing tool path, wherein the additive manufacturing tool path includes a plurality of planar layers stacked vertically. For example, see Figure 8, the additive manufacturing tool path can begin by forming the elements of the first wall 804, the second wall 806, the third wall 812, and the fifth wall 822, which are planar in the XZ plane relative to the axis system 899 at the Y coordinate of the additive manufacturing tool printing surface. The additive manufacturing tool path can then form subsequent planar layers (e.g., in the XZ plane) of the radiation shield element 802, which are stacked upward along the Y axis. In this way, each planar layer, wall, and extension of the radiation shield element 802 can be formed as a single continuous seamless element.

[0068] Fig.10 A method 1000 is presented for forming a radiation shielding element for an imaging device using additive manufacturing and a blend of tungsten and a polymer, wherein the amount of tungsten is 20% to 60% by volume relative to the polymer. The polymer is one of the following: polyamide (PA) 11, PA12, TPU, ABS, or an equivalent plastic. As described herein Figures 3 to 9 As described, the composition of the tungsten polymer blend (e.g., the amount of tungsten relative to the amount of polymer, and the type of polymer) enables the tungsten polymer blend to be heated to a molten state, wherein the tungsten polymer blend can be used by an additive manufacturing tool to form the geometry of a radiation shielding element. The tungsten polymer blend can be quickly cooled to a solid state, for example, within five seconds of being dispensed from an additive manufacturing tool in a molten state. In the solid state, the composition of the tungsten polymer blend provides structural rigidity to the radiation shielding element, enabling the formation of complex geometries, including a first wall and a second wall positioned at a non-zero angle relative to the first wall, the second wall connected to the first wall along a first axis, and additional third walls, fourth walls, and fifth walls, undercuts, grooves, through holes, fins, extensions, etc. The density of the tungsten polymer blend forming the radiation shielding element can be between 4000kg / m3 and 12000kg / m3. As described with respect to Figures 5 and 6 As described, the material density of the tungsten polymer blend can be adjusted by adjusting the wall thickness of the radiation shielding element (e.g., the tungsten polymer blend can have a variable material density in the range of 4000 kg / m3 to 12000 kg / m3). The wall thickness can be provided to an additive manufacturing tool as a parameter of the radiation shielding element, as further described herein. In this way, a radiation shielding element formed by additive manufacturing of a tungsten polymer blend of tungsten and a polymer can provide a desired shielding level, wherein the amount of tungsten is 20% to 60% by volume relative to the polymer, which further enables the radiation shielding element to have a complex geometry, which is used to provide more radiation shielding compared to conventional planar radiation shielding elements.

[0069] The method 1000 described further herein may be stored as executable instructions in a non-transitory memory on a computing device (or controller). The computing device may be coupled to one or more of a user input device and an additive manufacturing tool via a wired or wireless connection. The additive manufacturing tool may have a tungsten polymer blend of tungsten and a polymer in one or more of a powder form, a pellet form, or a filament form (e.g., a filament wound on a spool).

[0070] At 1002, method 1000 includes receiving data defining one or more parameters of a radiation shielding element. The data may be received by a computing device from a user input device, where a user may enter one or more parameters. In other embodiments, the data may be received by a computing device from a computer or other data storage device coupled to the computing device via a wired and / or wireless connection. The data defines one or more parameters of the radiation shielding element, which may be used to design a model representing the geometry of the radiation shielding element. For example, these parameters may include the number of walls; the angle between each wall; the number, size, and positioning of one or more through holes; the angle of the curved fins, through holes, or grooves; the wall thickness; the shape and size of each wall; and the like.

[0071] At 1004, method 1000 includes generating a digital model of a radiation shielding element from one or more parameters, the digital model including a first wall and a second wall positioned at a non-zero angle relative to the first wall, the second wall being connected to the first wall along a first axis. For example, the non-zero angle may be 90 degrees, greater than 0 degrees and less than 90 degrees, or greater than 90 degrees and less than 180 degrees. The digital model includes information from the one or more parameters and provides guidance for forming the radiation shielding element using additive manufacturing. In some embodiments, the digital model may also include a third wall connected to the first wall along a second axis different from the first axis of the first wall. In addition to the third wall, in another embodiment, the digital model also includes a fourth wall connected to the second wall along a third axis different from the first axis of the second wall, and connected to the third wall along a fourth axis different from the second axis of the third wall.

[0072] At 1006, method 1000 includes defining an additive manufacturing tool path for forming the radiation shield element as a single continuous shape based on the digital model. Figures 3 to 9The radiation shielding element includes at least a first wall and a second wall, and the first wall and the second wall are connected to each other, so that the first axis at the intersection of the first wall and the second wall is seamless. The additive manufacturing tool path may include a starting position, an end position, and one or more positions for pausing the dispensing of the tungsten polymer blend and moving the nozzle or printing surface of the additive manufacturing tool. For example, the additive manufacturing tool path may indicate a starting position at the lower left quadrant of the printing surface, and guide the nozzle to move and dispense the tungsten polymer blend of tungsten and polymer in a serpentine, zigzag pattern, so that each row of the dispensed material is in the same plane (e.g., a horizontal plane parallel to the printing surface) to form the first wall. After forming the first wall, the additive manufacturing tool path may guide the nozzle to pause dispensing the material, then move to a certain position along the first axis of the first wall, and then resume dispensing the material so that the nozzle forms the second wall. As further described herein, dispensing molten material (e.g., tungsten polymer blend of tungsten and polymer) can form the second wall as a continuation of the first wall, so that the materials of the first wall and the second wall are fused. In some embodiments, the additive manufacturing tool may have more than one nozzle, and the additive manufacturing tool path may include a path for each nozzle.

[0073] At 1008, method 1000 includes providing a tungsten polymer blend to an additive manufacturing tool, wherein the amount of tungsten is 20% to 60% by volume relative to the polymer. Providing the tungsten polymer blend to the additive manufacturing tool may include commanding the additive manufacturing tool to load the tungsten polymer blend from a storage device (e.g., from a filament spool, from a container of powder or pellets, etc.) into a dispensing element (e.g., a nozzle) of the additive manufacturing tool, the additive manufacturing tool being communicatively coupled to a computing device that performs method 1000. In some embodiments, the tungsten polymer blend may be provided as a molten compound, wherein a substantially pure volume of tungsten is substantially uniformly distributed throughout the polymer mixture. In other embodiments, the tungsten polymer blend may be provided to the additive manufacturing tool in one or more solid states, such as in powder form, pellet form, or filament form (e.g., a filament wound on a spool), and the tungsten polymer blend may be heated to a molten state by the additive manufacturing tool. For example, a filament (e.g., solid state) can be fed into a nozzle of an additive manufacturing tool, which can then heat the filament to a temperature at which the tungsten polymer blend becomes molten, with the tungsten being substantially uniformly distributed throughout the polymer mixture. For example, the molding temperature (e.g., the temperature at which the tungsten polymer blend is in a molten state) is between 200° C. and 300° C., depending on the application, and the method of manufacturing the radiation shielding element and process.

[0074] At 1010, method 1000 includes actuating an additive manufacturing tool to dispense molten compound into a predetermined position according to an additive manufacturing tool path. As described with respect to operation 1006, the predetermined position defines a single continuous geometry of a radiation shielding element having a first wall and a second wall positioned at a non-zero angle relative to the first wall, the second wall being connected to the first wall along a first axis. In an embodiment in which the digital model includes a third wall, dispensing the molten compound from the additive manufacturing tool into the predetermined position according to the additive manufacturing tool path may include dispensing the molten compound to form the third wall after dispensing the molten compound from the additive manufacturing tool into the predetermined position to form the first wall according to the additive manufacturing tool path. In an embodiment in which the digital model includes a third wall and a fourth wall, dispensing the molten compound from the additive manufacturing tool into the predetermined position according to the additive manufacturing tool path may include dispensing the molten compound to form the fourth wall after dispensing the molten compound from the additive manufacturing tool into the predetermined position to form the second wall and the third wall according to the additive manufacturing tool path.

[0075] The molten compound can be dispensed onto the printing surface from one or more nozzles of the additive manufacturing tool. For example, dispensing the molten compound from the additive manufacturing tool to a predetermined position according to the additive manufacturing tool path can include dispensing the molten compound from a first nozzle and a second nozzle of the additive manufacturing tool to form a first wall and a second wall, respectively. In other embodiments, dispensing the molten compound from the additive manufacturing tool to a predetermined position according to the additive manufacturing tool path includes dispensing the molten compound to form a first wall and then dispensing the molten compound to form a second wall. As described herein, the molten compound can be rapidly cooled from a molten state to a solid state (e.g., within 5 seconds after dispensing) to form a structurally rigid geometry of the radiation shielding element.

[0076] The technical effect of a single continuous radiation shielding element formed from a blend of tungsten and a polymer wherein the amount of tungsten is 20% to 60% by volume relative to the polymer is radiation shielding comparable to that provided by lead or other tungsten and polymer blend materials provided by a material that is widely available and can be easily formed into a wide variety of complex shapes while still being structurally stable.

[0077] When introducing the elements of various embodiments of the present disclosure, the articles "one", "a kind of" and "the" are intended to mean that there are one or more such elements. The terms "first", "second", etc. do not represent any order, amount or importance, but are used to distinguish one element from another element. The terms "include", "comprises", and "have" are intended to be inclusive, and mean that additional elements may also exist in addition to the listed elements. As used herein, the terms "connected to", "coupled to", etc., an object (e.g., material, element, structure, member, etc.) may be connected to or coupled to another object, regardless of whether the one object is directly connected or coupled to another object, or whether there are one or more intervening objects between the one object and another object. In addition, it should be understood that reference to "an embodiment" or "embodiment" of the present disclosure is not intended to be interpreted as excluding the existence of additional embodiments that are also combined with the cited features.

[0078] In addition to any previously indicated modifications, numerous other variations and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present specification, and the appended claims are intended to cover such modifications and arrangements. Therefore, although the information has been described in detail and in detail as described above in conjunction with what are currently considered to be the most practical and preferred aspects, it will be apparent to those of ordinary skill in the art that many modifications may be made, including but not limited to form, function, mode of operation, and use, without departing from the principles and concepts set forth herein. Likewise, as used herein, the examples and embodiments are intended to be illustrative in all respects only and should not be construed as limiting in any way.

Claims

1. A radiation shielding element (302) having a single continuous shape formed by a first wall (304) and a second wall (306) positioned at a non-zero angle (402) relative to the first wall, the second wall being connected to the first wall along a first axis (308), and the first wall and the second wall are both composed of a tungsten polymer blend, wherein the amount of tungsten relative to the polymer is 20% to 60% by volume.

2. The radiation shield element of claim 1, further comprising at least one of an undercut, a groove, a fin, or a through hole (310, 312, 314). 3 . The radiation shield element of claim 1 , wherein each of the first wall and the second wall is planar.

4. The radiation shield element of claim 1, wherein the first wall and the second wall of the radiation shield element are each between 0.2 mm and 6 mm.

5. The radiation shielding element of claim 1 , further comprising a third wall connected to the first wall along a second axis of the first wall different from the first axis, the third wall being comprised of the tungsten polymer blend of tungsten and the polymer, wherein the amount of tungsten relative to the polymer is 20% to 60% by volume.

6. The radiation shielding element of claim 5, further comprising a fourth wall connected to the second wall along a third axis of the second wall different from the first axis, and connected to the third wall along a fourth axis of the third wall different from the second axis, the fourth wall being composed of the tungsten-polymer blend of tungsten and the polymer, wherein the amount of tungsten relative to the polymer is 20% to 60% by volume.

7. The radiation shielding element of claim 1, wherein the polymer is one of the following: polyamide (PA) 11, PA 12, thermoplastic polyurethane (TPU), acrylonitrile butadiene styrene (ABS), or an equivalent plastic.

8. The radiation shield element of claim 1, wherein the tungsten polymer blend of tungsten and the polymer is capable of being transformed from a solid state to a molten state via exposure to heat.

9. The radiation shielding element of claim 1, wherein the tungsten polymer blend of tungsten and the polymer is one of a powder form, a pellet form, or a filament form prior to being used to form the radiation shielding element.

10. The radiation shielding element of claim 1, wherein the density of the tungsten polymer blend of tungsten and the polymer is between 4000 kg / m 3 With 12000kg / m 3 between.

11. A method (1000) of manufacturing a radiation shielding element, comprising: Receiving (1002) data defining one or more parameters of a radiation shielding element; generating (1004) a digital model of the radiation shield element from the one or more parameters, the digital model comprising a first wall and a second wall positioned at a non-zero angle relative to the first wall, the second wall being connected to the first wall along a first axis; defining (1006) an additive manufacturing tool path for forming the radiation shield element as a single continuous shape based on the digital model; providing (1008) a tungsten polymer blend to an additive manufacturing tool, the tungsten polymer blend comprising substantially pure volume tungsten substantially uniformly distributed throughout a polymer mixture, wherein the amount of tungsten is 20% to 60% by volume relative to the polymer mixture; as well as Actuating (1010) the additive manufacturing tool to dispense the tungsten polymer blend in a molten state into a predetermined position according to the additive manufacturing tool path, wherein the predetermined position defines a single continuous geometric shape of the radiation shielding element, the radiation shielding element having the first wall and the second wall positioned at the non-zero angle relative to the first wall, the second wall being connected to the first wall along the first axis.

12. The method of claim 11, wherein dispensing the tungsten polymer blend in the molten state from the additive manufacturing tool comprises directing the additive manufacturing tool to heat the tungsten polymer blend from a solid state to the molten state, and then dispensing the tungsten polymer blend in the molten state from a nozzle and a second nozzle of the additive manufacturing tool.

13. The method of claim 11, wherein providing the tungsten polymer blend to the additive manufacturing tool comprises providing the tungsten polymer blend in the molten state to the additive manufacturing tool.

14. The method of claim 11, wherein the digital model further comprises a third wall connected to the first wall along a second axis of the first wall different from the first axis, and dispensing the tungsten polymer blend from the additive manufacturing tool into the predetermined location according to the additive manufacturing tool path comprises: After completing dispensing the tungsten polymer blend from the additive manufacturing tool into the predetermined location to form the first wall according to the additive manufacturing tool path, dispensing the tungsten polymer blend to form the third wall.

15. The method of claim 14, wherein the digital model further comprises a fourth wall connected to the second wall along a third axis of the second wall different from the first axis and connected to the third wall along a fourth axis of the third wall different from the second axis, wherein dispensing the tungsten polymer blend from the additive manufacturing tool into the predetermined location according to the additive manufacturing tool path comprises: After completing dispensing the tungsten polymer blend from the additive manufacturing tool into the predetermined location to form the second wall and the third wall according to the additive manufacturing tool path, dispensing the tungsten polymer blend to form the fourth wall.

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