Computed tomography apparatus and its driving method

Abstract

To provide means for supplying electric energy to a rotation part in a non-contact state from the outside without using a mechanical contact point such as a slip ring.SOLUTION: There is provided a CT device having a non-contact optical feeding structure in which optical feeding elements are arranged along an outer peripheral surface of a rotation part in the CT device, and light emitting elements are arranged on a circumferential surface of a fixed part in the CT device, at positions opposed to the optical feeding elements.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a computer tomography apparatus having an optical power supply structure and a driving method thereof.

Background Art

[0002] An X-ray computer tomography apparatus (CT) includes a gantry including a rotating part that rotates around an imaging object, a bed moving device that moves a bed on which a subject is placed forward or backward in the body axis direction so as to pass through the inner peripheral part of the gantry, a slip ring that enables electrical connection with the rotating part, and an image forming part that processes data output from a detector, etc., and is composed of an operation part, a monitor part, etc. Conventionally, in order to read out an output signal of a detector or the like to the outside or supply power to the rotating part, transmission and reception of a control signal and an output signal, and power supply and reception are performed by a mechanical contact means called a slip ring. In order to ensure electrical connection by the slip ring, it is necessary to keep the rotation speed low and reduce the number of output signal lines from the detector. In order to reduce the number of signal lines, a method of serializing parallel signals and reading them out via a slip ring is adopted. However, when a large amount of imaging data is serially transmitted, the transmission frequency increases, so it is necessary to develop a dedicated semiconductor element such as a high-speed line buffer element. Furthermore, an increase in power consumption and heat generation accompanying an increase in the transmission frequency is inevitable. Since the slip ring rotates at high speed while sliding against the brush, particularly the contact surface of the power supply line that supplies power to the rotating part generates heat and causes seizure. Therefore, maintenance such as surface polishing of the slip ring and the brush and regular replacement of members is essential. As means for solving these problems, for example, a non-contact power supply structure by electromagnetic induction is known (Patent Documents 1 and 2). However, in order to supply sufficient electrical energy from the outside to the rotating part including an X-ray light source etc. in a non-contact state, it is necessary to arrange a large number of large permanent magnets, electromagnetic induction coils, etc. in the rotating part or the fixed part surrounding the rotating part, and the CT apparatus itself inevitably becomes larger and heavier.

Prior Art Documents

Patent Documents

[0003] [Patent Document 1] Japanese Patent Publication No. 2-224746 [Patent Document 2] Japanese Patent Publication No. 2001-258873 [Overview of the project] [Problems that the invention aims to solve]

[0004] The problem that this invention aims to solve is to provide a means for supplying electrical energy to a rotating part from the outside in a non-contact manner without using mechanical contacts such as slip rings. [Means for solving the problem]

[0005] Generally, when scanning a subject, such as a human body, with a CT scanner, the direction of movement of the subject is called the body axis direction. In a CT scanner, which consists of a gantry comprising a fixed part surrounding a circular rotating part that rotates with the body axis direction as its central axis and has a light source inside the rotating part, and a control unit that processes and displays image data obtained from the gantry, a photovoltaic power supply type CT scanner is provided in which a sheet-like arrangement or two or more photovoltaic elements are arranged at equal intervals along the outer surface of the rotating part, and a sheet-like arrangement or two or more light-emitting elements are arranged at equal intervals along the circumferential surface of the fixed part at a position opposite to the photovoltaic elements, and the light emitted from these light-emitting elements is converted into electrical energy by the photovoltaic elements at the opposite position and supplied to the electrical circuit built into the rotating part.

[0006] The CT scanner is a light-powered type in which the light source inside the rotating part is an X-ray light source. Preferably, by using an X-ray generator that uses carbon nanomaterials such as carbon nanotubes (CNTs) as field electron emission sources in the X-ray generation section, the light source section can be made smaller and consume less power.

[0007] The CT scanner is a light-powered type with a secondary battery, such as a lithium-ion battery, built into the rotating part.

[0008] This CT scanner uses a light-powered system that employs a sheet-like surface-emitting LED made of fluorescent acrylic or a reflector as a light-emitting element.

[0009] This is a light-powered CT scanner that uses a sheet-like photoelectric element employing a halide perovskite crystal or pyrite compound as a light-absorbing semiconductor.

[0010] The optically powered CT apparatus is configured such that the outer circumferential surface of the rotating part to which the photoelectric element is attached and the circumferential surface of the fixed part to which the light-emitting element is attached are parallel to the central axis. Preferably, the optically powered CT apparatus is configured such that a sheet-shaped photoelectric element is arranged in a curved manner along the outer circumferential surface of the rotating part.

[0011] The optically powered CT device has a rotating part to which a photovoltaic element is attached, and a fixed part to which a light-emitting element is attached, both of which are parallel to the central axis, and the rotating part contains a light source, a light source drive control circuit, a detector for detecting the optical signal emitted from the light source, and a detector control signal processing circuit for driving the detector and processing the detector's output signal.

[0012] The optically powered CT device has a rotating part to which a photovoltaic element is attached, and a fixed part to which a light-emitting element is attached, both of which are perpendicular to the central axis, and the rotating part contains a light source, a light source drive control circuit, a detector for detecting the optical signal emitted from the light source, and a detector control signal processing circuit for driving the detector and processing the detector's output signal.

[0013] The optically powered CT device has an outer circumferential surface of a rotating part to which a photovoltaic element is attached, and a circumferential surface of a fixed part to which a light-emitting element is attached, both of which are perpendicular to the central axis, and contains a light source and a light source drive control circuit inside the rotating part, a detector that detects the light signal emitted from the light source along the curved circumferential surface of the fixed part, and further contains a detector control signal processing circuit inside the fixed part that drives the detector and processes the output signal of the detector. [Effects of the Invention]

[0014] The slip rings supplying power to the rotating parts inside the gantry, especially the contact surfaces of the power lines, are free from concerns about overheating and seizing, and the maintenance burden of surface polishing of slip rings and brushes, as well as periodic replacement of components, can be reduced. Furthermore, the structure of the rotating parts inside the gantry and the surrounding fixed parts is simplified, enabling the CT device to be made smaller, lighter, and consume less power, significantly reducing the construction costs of the space, building, power supply, and air conditioning equipment required for the CT device installation. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1(a) is a side view of the CT apparatus 100 according to the first embodiment, viewed from the X-axis direction. Figure 1(b) is a plan view of the gantry 2 of the CT apparatus 100, viewed from the Z-axis direction. Figure 1(c) is an enlarged cross-sectional view of the portion indicated by A in Figure 1(a). [Figure 2] Figure 2(a) is a perspective view (1) to (3) illustrating modified examples (10-1, 10-2, 10-3) of the fixed part 4 of the gantry section of the CT device 100, particularly the structure of the light-emitting element 10. Figure 2(b) is a perspective view (1) to (3) illustrating modified examples (11-1, 11-2, 11-3) of the rotating part 3 of the gantry section of the CT device 100, particularly the structure of the power-generating element 11. Figure 2(c) is a cross-sectional view (1) to (3) illustrating modified examples of the structure of the rotating part 3 and fixed part 4 inside the gantry of the CT device 100. [Figure 3] Figure 3(a) is an example of a system block diagram (18) illustrating the power supply system according to the embodiment. Figure 3(b) is a plan view from the Z-axis illustrating the internal components of the rotating part. Figure 3(c) is a block diagram (18) of the photodetector signal processing, storage, and transfer circuit connected to the detector module (23). Figure 3(d) is a block diagram relating to the X-ray light source that irradiates the subject and its power supply circuit. [Figure 4]Figure 4(a) is a side view of the CT apparatus 200 according to the second embodiment, viewed from the X-axis direction. Figure 4(b) is an example of a cross-sectional structure with a portion of the part indicated by B in Figure 4(a) enlarged. Figure 4(c) is another example of a cross-sectional structure with a portion of the part indicated by B in Figure 4(a) enlarged. Figure 4(d) is a cross-sectional view viewed from the Z-axis direction to illustrate another modified example of the structure of the rotating part 3 and the fixed part 4. Figure 4(e) is an example of a cross-sectional structure with a portion of the part indicated by C in Figure 4(d) enlarged. [Figure 5] Figures 5(a) and 5(b) are plan views illustrating the structure of the power generation element (11) in the rotating part (3) of the CT device 200 as seen from the Z-axis direction. Figures 5(c) and 5(d) are plan views illustrating the structure of the light-emitting element (10) in the fixed part (4) of the CT device 200 as seen from the Z-axis direction. Figures 5(e) and 5(f) are enlarged cross-sectional views of the waist portion illustrating a modified example of the structure described in Figures 4(b) and 4(c) above. [Examples]

[0016] Figure 1 shows a CT scanner 100 according to the first embodiment. For the sake of explanation, in the present invention, as shown in the figure, the subject scanning direction (body axis direction) of the CT scanner is defined as the Z-axis, the vertical direction perpendicular to the Z-axis (up and down direction in the drawing) is defined as the Y-axis, and the direction perpendicular to the Z-axis and Y-axis is defined as the X-axis. Figure 1(a) is a side view of the CT scanner 100 as seen from the X-axis direction. The CT scanner 100 consists of a gantry section (2), a rotating section (3) inside the gantry, a fixed section (4) surrounding the rotating section, a rotating section drive motor (5) and timing belt (6) that rotate the rotating section, a patient movement device (7) that feeds the subject into the gantry section, a CT scanner drive control signal processing unit (8) that drives and scans the gantry section or processes imaging data, etc., and an output display recording unit (9) such as a monitor. The dashed line 1 indicates the rotation center axis of the rotating section (3).

[0017] FIG. 1(b) is a plan view of the gantry 2 of the CT apparatus 100 as viewed from the Z-axis direction. Between the rotating part (3) and the fixed part (4) surrounding the same, a light-emitting element (10) and a photovoltaic element (11) are arranged to face each other. That is, the photovoltaic element (11) is attached to the outer circumference of the rotating part (3), and the light-emitting element (10) is attached to the inner circumference of the fixed part (4). With this structure, the light energy of the light-emitting element (10) can be converted into electric energy by the photovoltaic element (11), and power can be supplied to the inside of the rotating part (3) in a non-contact state as described below. Note that the photovoltaic element (11) is generally often called a "solar cell". However, in the present invention, artificial light such as an LED is used instead of natural energy such as sunlight, so it is referred to as a "photovoltaic element".

[0018] The arrangement of the light-emitting element (10) and the photovoltaic element (11) will be described in more detail. FIG. 1(c) is an enlarged cross-sectional view of the portion indicated by A in FIG. 1(a). The rotating part (3) is composed of an outer circumferential part (3-1) that is parallel to the Z-axis and curved, and an outer surface part (3-2) that is composed of a plane perpendicular to the Z-axis. In this embodiment, the photovoltaic elements (11) are arranged over the entire circumference along the curved surface of the outer circumferential part (3-1). Therefore, a photovoltaic element that is easy to curve, for example, a sheet-like photovoltaic element using a halide-based perovskite crystal or a pyrite-based compound as a light-absorbing semiconductor, can be curved and used as the photovoltaic element (11). The photovoltaic element (11) is not limited to this, and a plurality of strip-shaped photovoltaic elements may be arranged on the outer circumferential part (3-1) so as to be parallel to the Z-axis, as will be described later.

[0019] In contrast, the light-emitting element (10) is arranged along the fixing portion (4) so as to face the photovoltaic element (11). More specifically, the fixing portion 4 includes an inner circumferential portion (4-1) that is parallel to the Z-axis and curved, and an inner surface portion (4-2) that is composed of a plane perpendicular to the Z-axis. That is, in this embodiment, the light-emitting element (10) is arranged along the inner circumferential portion (4-1) so as to face the photovoltaic element (11). Thus, the light-emitting element (10) and the photovoltaic element (11) can be arranged closely at an interval of, for example, about 1 mm to 1 cm, so that the energy loss due to photoelectric conversion can be minimized. Further, since artificial light such as LED or laser light is used for the light-emitting element (10), its emission wavelength can be easily adjusted to the wavelength at which the photovoltaic element (11) exhibits the highest photoelectric conversion efficiency.

[0020] A modification of the embodiment of the light-emitting element (10) and the photovoltaic element (11) will be described in more detail below with reference to FIG. 2. FIG. 2(a) shows three examples of the case where the light-emitting element (10) is arranged along the above-mentioned inner circumferential portion (4-1). The structure shown in (1) of FIG. 2(a) is a curved sheet-like light-emitting element (10-1), and the strip-shaped light-emitting element (10-1) is attached to the inner circumferential portion of the fixing portion 4. For the light-emitting element (10-1), for example, surface-emitting LEDs, other thin-film light-emitting elements, etc. can be used. Also, as shown in a partially enlarged view seen from the Z-axis direction, the strip-shaped light-emitting element (10-1) does not need to be formed completely integrally, and as shown in the figure, its joint, that is, the non-light-emitting portion may remain. Note that inside the fixing portion 4, a light-emitting element drive control circuit (12) for controlling the light-emitting element (10-1) is built in. The same is true for the modifications (2) and (3) of FIG. 2(a) described below.

[0021] The structure shown in (2) of Figure 2(a) is characterized by the fact that discrete light-emitting elements (10-2) are attached to a part of the inner circumference of the fixed part 4, and the same number of light-emitting elements (10-2) are attached to the inner circumference of the fixed part 4 at symmetrical positions on either side of the Z axis, as shown by the dashed line. This is because by selecting high-brightness light-emitting elements (10-2), it is not necessarily required to fill the entire inner circumference of the fixed part 4 with light-emitting elements (10-2). Examples of high-brightness, high-efficiency light-emitting elements include low-pressure or high-pressure sodium lamps. Furthermore, since the photovoltaic element (11) on the rotating part (3) is often rotating when the light-emitting elements (10-2) begin to emit light, there is considered to be little concern about partial degradation or burnout of the photovoltaic element (11).

[0022] The structure shown in (3) of Figure 2(a) is one in which a light-emitting element (10-3), which consists of a large number of micro-LEDs arranged in an array, is attached to part or all of the inner circumference of the fixing part 4. As shown in the partially enlarged view, the light-emitting elements (10-3) are arranged in an array, and it is possible to combine light-emitting elements with different emission wavelengths and different emission intensities, for example, in vertical columns, horizontal rows, or for each adjacent light-emitting part.

[0023] Figure 2(b) illustrates three examples of how the photoelectric element (11) can be arranged along the outer circumferential portion (3-1) described above. The structure shown in (1) of Figure 2(b) is a curved sheet-shaped photoelectric element (11-1), in which a strip-shaped photoelectric element (11-1) is attached to the outer circumferential portion of the rotating part 3. As already explained, the photoelectric element (11-1) is preferably a photoelectric element using a halide-based perovskite crystal or a pyrite-based compound formed on a film that can be easily bent as a light-absorbing semiconductor. Also, as shown in the partially enlarged view from the Z-axis direction, the strip-shaped photoelectric element (11-1) does not need to be formed completely integrally on the outer circumferential portion (3-1), and as shown in the figure, its joint, i.e., a non-photosensitive portion, may remain. The rotating part 3 contains a photoelectric element power supply circuit (13) for extracting the electrical energy generated by the photoelectric element (11-1). The same applies to the modified examples described below, as well as (2) and (3) in Figure 2(b).

[0024] The structure shown in (2) of Figure 2(b) consists of rectangular photovoltaic elements (11-2) arranged in a strip-like fashion on the outer circumference (3-1) with their longer sides parallel to the Z-axis, enclosing the entire outer circumference. This structure allows even photovoltaic elements that are difficult to bend, such as silicon-based photovoltaic elements formed on a glass substrate, to be approximately surrounded along the outer circumference.

[0025] The structure shown in (3) of Figure 2(b) is one in which a large number of photovoltaic elements (11-3) arranged in an array are attached to part or all of the inner circumference of the rotating part 3. As shown in the partially enlarged view, the photovoltaic elements (11-3) are arranged in an array, and it is also possible to combine photovoltaic elements having different spectral sensitivity spectra for each vertical column, horizontal row, or adjacent power generation cell.

[0026] Furthermore, any of the modified versions of the fixed part (4) shown in Figures 2(a)(1) to (3) can be combined with any of the modified versions of the rotating part 3 shown in Figures 2(b)(1) to (3).

[0027] Other modifications of the structure, other than the light-emitting element (10) and the photovoltaic element (11), relating to the rotating part (3) or the rotating part (3) and the fixed part (4), will be described below with reference to Figure 2(c). In the structure shown in Figure 2(c)(1), a slip ring, i.e., an annular electrode 14f, is placed on the side surface of the rotating part 3 (3-2 in Figure 1(c)). On the other hand, a convex electrode terminal 14m that makes an electrical connection with the electrode 14f is placed on the inner surface of the fixed part 4 (corresponding to 4-2 in Figure 1(c)), which is not shown. As mentioned above, there are technical challenges with the slip ring structure, but unlike the transmission of power, there are fewer drawbacks when transmitting digital signals other than power supply lines. Note that contactless communication means using electromagnetic waves may be used for the transmission of digital signals.

[0028] The structure shown in Figure 2(c)(2) has a permanent magnet (17) mounted inside the rotating part 3 on its side surface (3-2 in Figure 1(c)) so that the north and south poles alternate. On the other hand, an electromagnetic induction coil (16) is arranged along the inner surface of the stationary part (corresponding to 4-2 in Figure 1(c)) opposite the permanent magnet (17). An electromagnetic induction coil drive control circuit (15) is provided inside the stationary part (4). This structure constitutes a direct drive (DD) motor, so a rotating part drive motor (5) and a timing belt (6) for rotating the rotating part are not required. In addition, the rotational energy of the rotating part (3) after the imaging process is completed can be recovered as electrical energy by the electromagnetic induction coil (16).

[0029] In the structure shown in Figures 2(c) and 2(3), the electromagnetic induction coil (16) is mounted inside the rotating part (3) on the side surface of the rotating part (3-2 in Figure 1(c)), the opposite of Figure 2(c) and 2. On the other hand, a permanent magnet (17) is mounted along the inner surface of the fixed part 4 (corresponding to 4-2 in Figure 1(c)) so that the north and south poles alternate opposite each other, facing the electromagnetic induction coil (16). With this structure, the rotating part (3) is forcibly rotated by the rotating part drive motor (5) and the timing belt (6) for rotating the rotating part, generating an electromotive force in the electromagnetic induction coil (16), which can then charge a secondary battery such as a lithium-ion battery located inside the rotating part (3) via the electromagnetic induction coil drive control circuit (15). Therefore, it is possible to supplement the power supply to the rotating part (3) by optical power supply as described above. Furthermore, the rotational kinetic energy of the rotating part (3) after the imaging process is completed can be converted into electrical energy by an electromagnetic induction coil (16), and the kinetic energy can be recovered as electrical energy by charging the secondary battery located inside the rotating part (3).

[0030] Figure 3 will be used to explain other circuit configurations used in the CT device 100. Figure 3(a) is a system block diagram mainly relating to the power supply system. A photovoltaic element (11) and a light-emitting element (10) are connected to the system block (18), and are connected to the power bus line (19) via a photovoltaic element power supply circuit (13) and a light-emitting element drive control circuit (12), respectively. Furthermore, a communication control system (21) and a secondary battery (22) are also added, and after being controlled to the required voltage level by a bidirectional DC-DC converter (20), etc., charging or discharging operations are controlled for each part.

[0031] Figure 3(b) is a plan view illustrating the components of the rotating part (3) as seen from the Z-axis direction. The photoelectric element (11), which has already been described, is attached to the outer circumference of the rotating part (3). To visualize a subject (not shown) on the bed transfer device (7) using X-rays, an X-ray beam (27) is irradiated from the X-ray generator (25), and the transmitted X-rays are detected by the photodetector module (23). The X-ray generator (25) is driven and controlled by the X-ray circuit (26). The photodetector module (23) performs imaging, signal processing, image recording and transmission, etc., using a photodetector signal processing, memory, and transfer circuit block (24). The rotating part (3) also incorporates a secondary battery (22), the power control system block (18), which has already been described, and a communication control system (21) that transmits and receives control signals and imaging data to and from the outside of the rotating part (3).

[0032] Figure 3(c) is a block diagram illustrating the main circuit elements constituting the photodetector signal processing, memory, and transfer circuit block (24). The detector module (23) is driven and controlled by the photodetector module drive circuit (31), which drives each pixel array (30). The detection signal output from each pixel array (30) is transferred to the digital signal processing circuit (34) via the signal amplification / AD conversion circuit (32), signal scanning control circuit (33), etc. The processed imaging data is recorded in the image memory (35) via the bus line (36). Alternatively, it is transferred via the parallel-to-serial conversion circuit (37) to the input / output interface (38), for example, the slip ring described in Figure 2(c)(1), or to the communication control system (21) described in Figure 3(a).

[0033] Figure 3(d) is a block diagram relating to the X-ray source (25) and its power supply circuit (26) for irradiating the subject. The X-ray source (25) may use a conventional X-ray tube, but it can also use an X-ray generator made of carbon nanomaterials. Specifically, the X-ray source (25) is composed of a carbon nanomaterial electron beam generating cathode (25C) and an anode target (25A). The power supply circuit (26) is composed of a high-voltage control circuit (26-1) and a voltage boosting circuit (26-2). Preferably, the high-voltage control circuit (26-1) can be made transformerless by using a switching power supply, power semiconductors, etc.

[0034] Figure 4(a) is a side view of the CT apparatus 200 according to the second embodiment, viewed from the X-axis direction. The difference from the CT apparatus 100 according to the first embodiment is the structure of the rotating part (3) and the fixed part (4), indicated by the dashed lines, particularly the parts enclosed by B and B'. The other configurations have been explained in the description of the CT apparatus 100 according to the first embodiment, so they are omitted here.

[0035] Figure 4(b) is an enlarged cross-sectional view of the structure of the part enclosed by B in Figure 4(a). The rotating part (3) consists of an outer circumference (3-1) that is parallel to the Z axis and curved, and an outer surface (3-2) that is a plane perpendicular to the Z axis. On the other hand, the fixed part (4) consists of an inner circumference (4-1) that is parallel to the Z axis and curved, and an inner surface (4-2) that is a plane perpendicular to the Z axis. In this embodiment, unlike the first embodiment, the photoelectric element (11) is attached to the outer surface (3-2) of the rotating part (3), and the light-emitting element (10) is arranged on the inner surface (4-2) of the fixed part (4) opposite to it. Therefore, it is not necessary to curve either the photoelectric element (11) or the light-emitting element (10). In this figure, the photoelectric element (11) is arranged on both sides of the rotating part (3), but as will be described later (for example, Figure 5(f)), the photoelectric element (11) may be arranged on only one side. In this way, the light-emitting element (10) and the photoelectric element (11) can be arranged in close proximity, for example, with a distance of about 1 mm to 1 cm between them, so that energy loss due to photoelectric conversion can be minimized. Furthermore, since artificial light such as LED or laser light is used for the light-emitting element (10), its emission wavelength can be easily matched to the wavelength at which the photoelectric conversion efficiency is highest as exhibited by the photoelectric element (11).

[0036] Figure 4(c) is an example of a cross-sectional structure illustrating the structure in which multiple photodetector modules (23) are arranged continuously or at equal intervals along the inner circumferential surface (4-1) of the fixed part in Figure 3(b). Because the photodetector modules (23) are located in the fixed part, an opening (40) is formed for the X-rays (27) that have passed through the subject to be transmitted. Since the photoelectric element (11) is attached to the outer surface (3-2) of the rotating part (3), and the light-emitting element (10) is positioned on the inner surface (4-2) of the fixed part (4) opposite to it, there is an advantage in that the opening (40) can be formed on the outer circumferential surface (3-1) of the rotating part.

[0037] Figure 4(d) shows a plan view of the rotating part (3) and the fixed part (4) when the aperture (40) is viewed from the Z-axis direction. An aperture (40) corresponding to the area to which X-rays are irradiated is formed in the rotating part (3), and the X-rays (27) that pass through the aperture (40) expose the light-receiving surface of the detector module (23). Although not shown in the figure, the photovoltaic element (11) that has already been described is attached to the side part (3-2) of the rotating part (3). The part enclosed by C in the same figure will be described below.

[0038] Figure 4(e) is an enlarged view of the area enclosed by C in Figure 4(d). The detector module (23) has multiple photodetectors or pixel arrays densely arranged along the circumference of the inner surface (4-1) of the fixed part. Therefore, the photodetector signal processing, memory, and transfer circuit block (24), the photodetector module drive circuit (31), etc., described in Figure 3(b) are located in the fixed part (4).

[0039] Figures 5(a) and 5(b) are plan views from the Z-axis direction illustrating modified examples of the photovoltaic element (11) attached to the side portion (3-2) of the rotating portion (3). In the case of Figure 5(a), the structure is formed by creating a ring-shaped sheet-like photovoltaic element (11) as described in Figure 2(b)(1). Unlike the case of Figure 2(b)(1), it is not necessary to curve it, but it has the advantage that it is easy to create a photovoltaic element that has been processed into a ring shape.

[0040] Figure 5(b) shows a structure in which multiple rectangular elements are arranged at equal intervals on the side surface (3-2) of the rotating part (3) as photovoltaic elements (11). Widely used photovoltaic elements, i.e., solar panels, can be used, but it is difficult to completely fill the side surface (3-2). Therefore, as explained in Figure 5(d) below, the shape of the light-emitting element (10) and the shape of the photovoltaic elements (11) are almost identical, and the light-emitting element (10) emits light only when the light-emitting element (10) and the photovoltaic elements (11) are facing each other, thereby suppressing energy loss.

[0041] Figure 5(c) shows a structure in which a sheet-like light-emitting element (10) is formed in an annular shape, as explained in Figure 2(a)(1). Unlike the case in Figure 2(a)(1), there is no need to curve it, and it has the advantage that the annularly processed light-emitting element can be created in a planar manner.

[0042] As explained in Figures 2(a) and 2(2), Figure 5(d) shows a configuration in which discrete light-emitting elements (10) are attached to a portion of the inner circumference of the fixed part 4. The same number of light-emitting elements (10-2) are also attached to the inner surface of the fixed part 4 at symmetrical positions across the Z-axis, as shown by the dashed lines. This is because, by selecting high-brightness light-emitting elements (10), it is not necessarily required to fill the entire inner surface of the fixed part 4 with light-emitting elements (10). Furthermore, since the photovoltaic elements (11) on the rotating part (3) are often rotating when the light-emitting elements (10) begin to emit light, there is little concern about partial degradation or burnout of the photovoltaic elements (11).

[0043] Figure 5(e) shows a modified configuration including the induction coil (16) and permanent magnet (17) described in Figure 2(c)(2). The difference from the structure in Figure 2(c)(2) is that the induction coil (16) is located on the inner surface (4-1) of the fixed part, and the permanent magnet (17) is located on the outer circumference of the rotating part. Similarly, the contact terminal (14f) on the rotating part side and the convex contact terminal (14m) on the fixed part side are located on the outer circumference of the rotating part and on the inner surface (4-1) of the fixed part, respectively.

[0044] On the other hand, in the modified example shown in Figure 5(f), since the X-ray aperture (40) is formed on the outer circumference of the rotating part (30), the induction coil (16) is located on the inner surface (4-2) of the fixed part and the permanent magnet (17) is located on the outer surface of the rotating part.

[0045] In addition, both the CT apparatus 100 according to the first embodiment and the CT apparatus 200 according to the second embodiment have a structure in which the patient's bed is moved in the direction of the body axis (Z axis) by a bed movement device (7) relative to a fixed gantry section (2). However, it is clear that the present invention can also be applied to a CT apparatus in which the gantry section (2) moves in the direction of the body axis (Z axis) while the patient's bed is fixed. [Industrial applicability]

[0046] This invention makes it easy to realize mobile medical means such as small vehicles and aircraft equipped with a CT scanner. Furthermore, by combining it with AI, high-speed communication methods, etc., it is expected to detect various abnormalities that may occur in the human body from a broad perspective without overlooking any, enabling rapid and flexible medical and life-saving activities in remote areas, disaster sites, conflict zones, etc. [Explanation of Symbols]

[0047] 1: Rotation center axis, 2: Gantry, 3: Rotating part, 4: Fixed part, 5: Rotating part drive motor, 6: Rotating part rotation belt, 7: Bed movement device, 8: CT device drive control unit, 9: Display device, 10: Light-emitting element, 11: Photoelectric element, 12: Light-emitting element drive control circuit, 13: Photoelectric element power supply circuit, 14f: Contact terminal on the rotating part side, 14m: Convex contact terminal on the fixed part side, 15: Electromagnetic induction coil drive control circuit, 16: Induction coil, 17: Permanent magnet, 18: Power control system block diagram, 19: Power bus line, 20: Bidirectional DC-DC converter, 21: Communication Control system, 22: Secondary battery, 23: Photodetector module, 24: Photodetector signal processing, memory, and transfer circuit block, 25: X-ray generator, 26: X-ray circuit, 26-1: High-voltage control circuit, 26-2: Voltage boosting circuit, 27: X-ray beam, 30: Pixel array, 31: Photodetector module drive circuit, 32: Signal amplification / AD conversion circuit, 33: Signal scanning control circuit, 34: Digital signal processing circuit, 35: Image memory, 36: Bus line, 37: Parallel-to-serial conversion circuit, 38: Input / output interface, 40: X-ray aperture in the rotating part

Claims

1. A CT scanner comprising: an annular rotating part that rotates with the axis of rotation of the subject's body axis as the central axis of rotation; a timing belt attached to the rotating part and a rotating part drive motor that rotates the timing belt; a fixed part with a curved inner circumference surrounding the outer circumference of the annular rotating part located inside a gantry section; a bed moving device for moving the subject through the inner circumference of the gantry section; a control unit for processing and displaying image data obtained from the gantry section; and a photoelectric element made of a light-absorbing semiconductor formed on a film attached along the entire circumference of the outer circumferential surface of the annular rotating part, which is curved parallel to and surrounding the axis of rotation of the annular rotating part; and a light-emitting element located on the inner circumferential surface of the curved inner circumference of the fixed section, opposite to the photoelectric element.

2. The CT apparatus according to claim 1, wherein the light-absorbing semiconductor is a halide-based perovskite crystal.

3. The CT apparatus according to claim 1, wherein the light-absorbing semiconductor is a pyrite-based compound.

4. The CT apparatus according to claim 1, wherein the CT apparatus is an X-ray CT apparatus, and the X-ray generating unit used in the rotating section uses carbon nanomaterials as a field electron emission source.

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