JP7842320B2 - Computed tomography apparatus and its driving method - Google Patents

Description

This invention relates to a computed tomography apparatus having an optical power supply structure and a method for driving the same.

An X-ray computed tomography (CT) system consists of a gantry including a rotating part that rotates around the object to be imaged, a bed movement device that moves the patient's bed forward or backward in the axial direction so that it passes through the inner circumference of the gantry, slip rings that enable electrical connection with the rotating part, and an operation and monitoring unit including an image rendering unit that processes data output from the detector. Conventionally, in order to read out output signals from the detector or other devices to the outside, or to supply power to the rotating part, control signals and output signals, as well as power, are transmitted and received using mechanical contact means called slip rings. In order to ensure electrical connection by slip rings, 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 is adopted in which parallel signals are serialized and read out via slip rings. However, when a large amount of imaging data is transmitted serially, the transmission frequency increases, so it is necessary to develop dedicated semiconductor elements such as high-speed line buffer elements. Furthermore, an increase in power consumption and heat generation due to the increase in transmission frequency is unavoidable. Because the slip rings rotate at high speed and slide against the brushes, the contact surfaces of the power lines supplying power to the rotating parts, in particular, overheat and can cause seizing. Therefore, regular maintenance, such as surface polishing of the slip rings and brushes, and periodic replacement of components, is essential. As a means to solve these problems, for example, non-contact power supply structures using electromagnetic induction are known (Patent Documents 1 and 2). However, in order to supply sufficient electrical energy to the rotating part containing the X-ray light source, etc., from an external source in a non-contact manner, it is necessary to place many large permanent magnets and electromagnetic induction coils in the rotating part and the surrounding fixed part, which inevitably leads to an increase in the size and weight of the CT scanner itself.

Japanese Patent Publication No. 2-224746 Japanese Patent Publication No. 2001-258873

The problem that this invention aims to solve is to provide a means for supplying electrical energy to a rotating part from an external source in a non-contact manner, without using mechanical contacts such as slip rings.

Generally, when scanning a subject, such as a human body, with a CT scanner, the direction of the subject's movement is called the body axis direction. This CT scanner consists of a gantry comprising a fixed section surrounding a circular rotating section that rotates around the body axis direction, and a light source located inside the rotating section; and a control unit that processes and displays image data obtained from the gantry. In this optically powered CT scanner, sheet-like or multiple photoelectric elements are arranged at equal intervals along the outer circumferential surface of the rotating section, and sheet-like or multiple multiple light-emitting elements are arranged at equal intervals along the circumferential surface of the fixed section opposite the photoelectric elements. Light emitted from these light-emitting elements is converted into electrical energy by the photoelectric elements at the opposing positions and supplied to electrical circuits built into the rotating section.

The CT scanner is a light-powered type in which the light source inside the rotating section 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.

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

This CT apparatus 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.

This CT (Computer Telescope) system utilizes a sheet-like photovoltaic element employing a halide-based perovskite crystal or pyrite-based compound as a light-absorbing semiconductor.

The CT apparatus is a light-powered type in which 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 CT apparatus is a light-powered type in which a sheet-shaped photoelectric element is arranged in a curved manner along the outer circumferential surface of the rotating part.

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

The CT device is a light-powered type in which the outer circumferential surface of a rotating part to which a photoelectric element is attached and the circumferential surface of a fixed part to which a light-emitting element is attached 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.

This optically powered CT device has a rotating section to which a photovoltaic element is attached, and a fixed section to which a light-emitting element is attached, both of which are perpendicular to the central axis. The rotating section contains a light source and a light source drive control circuit. A detector is positioned along the curved circumferential surface of the fixed section to detect the light signal emitted from the light source. Furthermore, the fixed section contains a detector control signal processing circuit that drives the detector and processes its output signal.

This design eliminates concerns about overheating and seizing of the slip rings supplying power to the rotating parts inside the gantry, particularly at the contact surfaces of the power lines. It also reduces the maintenance burden associated with surface polishing of slip rings and brushes, and periodic replacement of components. Furthermore, the simplified structure of the rotating parts and surrounding fixed parts inside the gantry allows for a smaller, lighter, and more energy-efficient CT system, significantly reducing construction costs for the space required for the CT system, as well as for building, power supply, and air conditioning equipment.

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(a) shows perspective views (1) to (3) illustrating modified structures (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) shows perspective views (1) to (3) illustrating modified structures (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) shows cross-sectional views (1) to (3) illustrating modified structures (1) to (3) of the rotating part 3 and fixed part 4 inside the gantry of the CT device 100. 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(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. 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 apparatus 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 apparatus 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.

Figure 1 shows a CT scanner 100 according to the first embodiment. For convenience of explanation, in this invention, as shown in the figure, the scanning direction of the CT scanner (body axis direction) 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 patient 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).

Figure 1(b) is a plan view of the gantry 2 of the CT apparatus 100, viewed from the Z-axis direction. Between the rotating part (3) and the surrounding fixed part (4), a light-emitting element (10) and a photoelectric element (11) are arranged facing each other. Specifically, the photoelectric element (11) is mounted on the outer circumference of the rotating part (3), and the light-emitting element (10) is mounted on the inner circumference of the fixed part (4). This structure allows the light energy of the light-emitting element (10) to be converted into electrical energy by the photoelectric element (11), and power can be supplied to the inside of the rotating part (3) in a non-contact manner, as described below. Note that the photoelectric element (11) is generally often called a "solar cell." However, in this invention, artificial light such as LEDs is used instead of natural energy such as sunlight, so it will be called a "photoelectric element."

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

In contrast, the light-emitting element (10) is positioned along the fixing portion (4) so as to face the photoelectric element (11). More specifically, the fixing portion 4 consists of an inner circumferential portion (4-1) that is parallel to the Z-axis and curved, and an inner surface portion (4-2) that is a plane perpendicular to the Z-axis. That is, in this embodiment, the light-emitting element (10) is positioned along the inner circumferential portion (4-1) so as to face the photoelectric element (11). In this way, the light-emitting element (10) and the photoelectric element (11) can be positioned closely together, for example, with a distance of about 1 mm to 1 cm, so 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 when emitted by the photoelectric element (11).

Modified examples of the embodiment of the light-emitting element (10) and photovoltaic element (11) will be described in more detail below with reference to Figure 2. Figure 2(a) illustrates three examples of cases where the light-emitting element (10) is arranged along the inner circumferential portion (4-1) described above. The structure shown in (1) of Figure 2(a) is a curved sheet-shaped light-emitting element (10-1), in which a strip-shaped light-emitting element (10-1) is attached to the inner circumferential portion of the fixing part 4. For the light-emitting element (10-1), for example, a surface-emitting LED, or other thin-film light-emitting elements can be used. Also, as shown in the partially enlarged view from the Z-axis direction, the strip-shaped light-emitting element (10-1) does not need to be formed as a completely integrated unit, and as shown, its joints, i.e., non-emitting portions, may remain. A light-emitting element drive control circuit (12) for controlling the light-emitting element (10-1) is built into the fixing part 4. The same applies to (2) and (3) of Figure 2(a) described below.

The structure shown in (2) of Figure 2(a) is characterized by the attachment of discrete light-emitting elements (10-2) to a portion of the inner circumference of the fixed part 4, and by the attachment of the same number of light-emitting elements (10-2) 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, concerns about partial degradation or burnout of the photovoltaic element (11) are considered to be minimal.

The structure shown in (3) of Figure 2(a) is one in which a light-emitting element (10-3), consisting of numerous 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 even in adjacent light-emitting sections.

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).

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.

The structure shown in (3) of Figure 2(b) is one in which a large number of photoelectric 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 photoelectric elements (11-3) are arranged in an array, and it is possible to combine photoelectric elements having different spectral sensitivity spectra for each vertical column, horizontal row, or adjacent power generation cell.

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).

Other modifications of the structure, excluding the light-emitting element (10) and the photovoltaic element (11), related to the rotating part (3) or the structure of the rotating part (3) and the fixed part (4), will be described below using Figure 2(c). The structure shown in Figure 2(c)(1) has a slip ring, i.e., an annular electrode 14f, 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, which makes an electrical connection to 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, the slip ring structure has technical challenges, but unlike power transmission, it has fewer drawbacks when transmitting and receiving digital signals other than power supply lines. Furthermore, contactless communication means using electromagnetic waves may be used for transmitting and receiving digital signals.

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 positioned 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, eliminating the need for a rotating part drive motor (5) and a timing belt (6) for rotating the rotating part. Furthermore, the rotational energy of the rotating part (3) after the imaging process can be recovered as electrical energy by the electromagnetic induction coil (16).

In the structure shown in Figure 2(c)(3), the electromagnetic induction coil (16) is mounted inside the rotating part (3) on the side surface of the rotating part 3 (3-2 in Figure 1(c)), the opposite of Figure 2(c)(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, after the imaging process is complete, the rotational kinetic energy of the rotating part (3) can be converted into electrical energy by the electromagnetic induction coil (16), and the secondary battery located inside the rotating part (3) can be charged, thereby recovering the kinetic energy as electrical energy.

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 related to the power supply system. The system block (18) is connected to a photovoltaic element (11) and a light-emitting element (10), which are then 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 included, 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.

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), previously described, is attached to the outer circumference of the rotating part (3). To X-ray imaging a subject (not shown) on the bed transfer device (7), 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., through the photodetector signal processing, memory, and transfer circuit block (24). The rotating part (3) also incorporates a secondary battery (22), the previously described power control system block (18), and a communication control system (21) for sending and receiving control signals and imaging data with the outside of the rotating part (3).

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 controls each pixel array (30). The detection signals output from each pixel array (30) are 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), such as the slip ring described in Figure 2(c)(1), or to the communication control system (21) described in Figure 3(a).

Figure 3(d) is a block diagram relating to the X-ray light source (25) and its power supply circuit (26) for irradiating the subject. While a conventional X-ray tube may be used for the X-ray light source (25), an X-ray generation unit using carbon nanomaterials can also be used. Specifically, the X-ray light source (25) is composed of a carbon nanomaterial electron beam generation cathode (25C) and an anode target (25A). The power supply circuit (26) consists 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.

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 lies in the structure of the rotating part (3) and the fixed part (4), particularly the parts enclosed by B and B', indicated by the dashed lines. Other configurations were explained in the description of the CT apparatus 100 according to the first embodiment and are therefore omitted here.

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 circumferential part (3-1) that is parallel to the Z axis and curved, and an outer surface part (3-2) that is a plane perpendicular to the Z axis. On the other hand, the fixed part (4) consists of an inner circumferential part (4-1) that is parallel to the Z axis and curved, and an inner surface part (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 part (3-2) of the rotating part (3), and the light-emitting element (10) is arranged on the inner surface part (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. Thus, 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, thereby minimizing energy loss due to photoelectric conversion. Furthermore, since the light-emitting element (10) uses artificial light such as LED or laser light, its emission wavelength can be easily matched to the wavelength at which the photoelectric element (11) exhibits the highest photoelectric conversion efficiency.

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, as shown in Figure 3(b). Because the photodetector modules (23) are located on the fixed part, an aperture (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 opposite it on the inner surface (4-2) of the fixed part (4), there is an advantage in that the aperture (40) can be formed on the outer circumferential surface (3-1) of the rotating part.

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), which has already been described, is attached to the side portion (3-2) of the rotating part (3). The part enclosed by C in the figure will be described below.

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 on the fixed part (4).

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 part (3). In the case of Figure 5(a), the structure is formed by creating a ring-shaped sheet-like photovoltaic element (11), as explained in Figure 2(b)(1). Unlike the case of Figure 2(b)(1), curvature is not necessary, but it has the advantage of being easy to manufacture a photovoltaic element with a ring shape.

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). While widely used photovoltaic elements, i.e., solar panels, can be used, 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 energy loss can be suppressed by emitting light only when the light-emitting element (10) and the photovoltaic elements (11) are facing each other.

Figure 5(c) shows a structure in which a sheet-like light-emitting element (10) is formed in a ring shape, as explained in Figure 2(a)(1). Unlike the case in Figure 2(a)(1), there is no need to curve the element, and it has the advantage of being able to create a ring-shaped light-emitting element in a planar manner.

Figure 5(d), as explained in Figures 2(a) and 2(2), shows a configuration in which discrete light-emitting elements (10) are attached to a portion of the inner circumference of the fixed part 4. As shown by the dashed lines, 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. This structure is characterized by the selection of high-brightness light-emitting elements (10), eliminating the need to completely fill the inner surface of the fixed part 4 with light-emitting elements (10). Furthermore, since the photovoltaic element (11) on the rotating part (3) is often rotating when the light-emitting elements (10) begin to emit light, concerns about partial degradation or burnout of the photovoltaic element (11) are considered minimal.

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 circumferential 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 circumferential surface (4-1) of the fixed part, respectively.

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.

Furthermore, 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 body axis (Z axis) direction 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 patient's bed is fixed while the gantry section (2) moves in the body axis (Z axis) direction.

This invention facilitates the realization of mobile medical means such as small vehicles and aircraft equipped with a CT scanner. Furthermore, by combining it with AI, high-speed communication systems, 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.

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 generation unit, 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 unit

Claims (4)

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 the gantry; a bed moving device for moving the subject through the inner circumference of the gantry; a control unit for processing and displaying image data obtained from the gantry; and further comprising 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 part, opposite to the photoelectric element. The CT apparatus according to claim 1, wherein the light-absorbing semiconductor is a halide-based perovskite crystal. The CT apparatus according to claim 1, wherein the light-absorbing semiconductor is a pyrite-based compound. 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.