Computer tomography device and driving method thereof

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 technology]

[0002] An X-ray computed tomography (CT) system is composed of a gantry including a rotating part that rotates around the object to be imaged, a bed moving device that moves the bed on which the subject is placed forward or backward in the direction of the body axis so that it passes through the inner circumference of the gantry, a slip ring that enables electrical connection with the rotating part, and an operation and monitor part including an image rendering part that processes data output from the detector. Conventionally, in order to read the output signal of the detector to the outside or to supply power to the rotating part, a mechanical contact means called a slip ring is used to send and receive control signals and output signals, and to give and receive power. 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. To reduce the number of signal lines, a method is adopted in which parallel signals are serialized and read out through a slip ring. However, since the transmission frequency increases when a large amount of imaging data is transmitted serially, it is necessary to develop dedicated semiconductor elements such as high-speed line buffer elements. Furthermore, increases in power consumption and heat generation due to the increase in transmission frequency are unavoidable. Since the slip ring rotates at high speed and while sliding against the brush, the contact surface of the power line that supplies power to the rotating part in particular heats up and causes burn-in. For this reason, maintenance such as polishing the surfaces of slip rings and brushes and periodic replacement of components is essential. As a means for solving these problems, for example, a non-contact power supply structure using electromagnetic induction is known (Patent Documents 1 and 2). However, in order to supply sufficient electrical energy from the outside in a non-contact manner to a rotating part that contains an X-ray light source, etc., it is necessary to place a large number of large permanent magnets and electromagnetic induction coils in the rotating part and the fixed part surrounding the rotating part, which inevitably increases the size and weight of the CT device itself. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP2-224746 [Patent Document 2] Patent Publication No. 2001-258873 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide a means for supplying electrical energy to a rotating part from the outside in a non-contact state without passing through mechanical contacts such as slip rings. [Means for solving the problem]

[0005] In general, when a subject, for example, a human body, is scanned in a CT scanner, the direction of movement of the subject is called the body axis direction. In this CT scanner, which is composed of a gantry consisting of a fixed part surrounding the rotating part and having a light source inside a circular rotating part that rotates around the body axis direction as its central axis, and a control part that processes and displays image data obtained from the gantry, a sheet-like or two or more multiple photovoltaic elements are arranged at equal intervals along the outer circumferential surface of the rotating part, and a sheet-like or two or more multiple light-emitting elements are arranged at equal intervals along the circumferential surface of the fixed part at a position opposite the photovoltaic elements, and the light irradiated from the light-emitting elements is converted into electrical energy by the photovoltaic elements at the opposing position, and the electrical energy is supplied to an electrical circuit or the like built into the rotating part.

[0006] The light source inside the rotating part is an optically powered CT device that is an X-ray light source. Preferably, an X-ray generator that uses carbon nano materials such as carbon nanotubes (CNTs) as a field electron emission source in the X-ray generating part is used, thereby making the light source part smaller and less consuming power.

[0007] The CT device will be an optically powered type with a secondary battery such as a lithium-ion battery built into the rotating part.

[0008] The CT device is an optically powered type that uses a sheet-shaped surface-emitting LED made of fluorescent acrylic or a reflector as the light-emitting element.

[0009] The optically powered CT device uses a sheet-shaped photovoltaic element that uses halide perovskite crystals or pyrite compounds as light-absorbing semiconductors.

[0010] The optically powered CT device has an outer peripheral 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, which are parallel to a central axis. Preferably, the optically powered CT device has a sheet-shaped photovoltaic element curved and arranged to fit along the outer peripheral surface of the rotating part.

[0011] The outer peripheral surface of the rotating part to which the photovoltaic 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, and the optically powered CT device has a light source inside the rotating part, a light source drive control circuit, a detector that detects the optical signal emitted from the light source, and a detector control signal processing circuit that drives the detector and processes the output signal from the detector.

[0012] The outer peripheral surface of the rotating part to which the photovoltaic element is attached and the circumferential surface of the fixed part to which the light-emitting element is attached are perpendicular to the central axis, and the optically powered CT device has a light source inside the rotating part, a light source drive control circuit, a detector that detects the optical signal emitted from the light source, and a detector control signal processing circuit that drives the detector and processes the output signal from the detector.

[0013] The outer peripheral surface of the rotating part to which the photovoltaic element is attached, and the circumferential surface of the fixed part to which the light-emitting element is attached are perpendicular to the central axis, the rotating part has a light source and a light source drive control circuit inside, a detector is disposed along the curved circumferential surface of the fixed part to detect the optical signal emitted from the light source, and the fixed part further has a detector control signal processing circuit inside for driving the detector and processing the detector's output signal. Effect of the Invention

[0014] There is no need to worry about heat generation or burning of the slip ring that supplies power to the rotating part inside the gantry, especially the contact surface of the power line, and it reduces the maintenance burden of polishing the surfaces of the slip ring and brushes and regular replacement of parts, etc. In addition, because the structure of the rotating part inside the gantry and the fixed parts surrounding the rotating part is simplified, the CT system can be made smaller, lighter, and consumes less power, and the space required to install the CT system, as well as the construction costs for the building, power supply, and air conditioning equipment, can be significantly reduced. [Brief description of the drawings]

[0015] [Figure 1] Fig. 1(a) is a side view of a CT scanner 100 according to a first embodiment as viewed from the X-axis direction. Fig. 1(b) is a plan view of a gantry 2 of the CT scanner 100 as viewed from the Z-axis direction. Fig. 1(c) is an enlarged cross-sectional view of a portion indicated by A in Fig. 1(a). [Diagram 2] FIG. 2(a) is perspective views (1) to (3) illustrating modified examples (10-1, 10-2, 10-3) relating to the structure of the fixed part 4 of the gantry part of the CT device 100, in particular the structure of the light emitting element 10. FIG. 2(b) is perspective views (1) to (3) illustrating modified examples (11-1, 11-2, 11-3) relating to the structure of the rotating part 3 of the gantry part of the CT device 100, in particular the structure of the power generating element 11. FIG. 2(c) is cross-sectional views (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. [Diagram 3] Fig. 3(a) is an example of a system block diagram (18) explaining a power supply system according to the embodiment. Fig. 3(b) is a plan view from the Z axis explaining the internal components of the rotating part. Fig. 3(c) is a block diagram (18) of a photodetector signal processing, storage and transfer circuit connected to a detector module (23). Fig. 3(d) is a block diagram of an X-ray light source that irradiates an object and its power supply circuit. [Figure 4]FIG. 4(a) is a side view of the CT device 200 according to the second embodiment as viewed from the X-axis direction. FIG. 4(b) is an example of a cross-sectional structure obtained by partially enlarging the portion indicated by B in FIG. 4(a). FIG. 4(c) is another example of a cross-sectional structure obtained by partially enlarging the portion indicated by B in FIG. 4(a). FIG. 4(d) is a cross-sectional view obtained by viewing from the Z-axis direction to explain another modified example of the structure of the rotating unit 3 and the fixed unit 4. FIG. 4(e) is an example of a cross-sectional structure obtained by partially enlarging the portion indicated by C in FIG. 4(d). [Diagram 5] Figures 5(a) and 5(b) are plan views illustrating the structure of the power generating element (11) in the rotating part (3) of the CT device 200 as viewed 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 viewed 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). EXAMPLES

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

[0017] FIG. 1(b) is a plan view of the gantry 2 of the CT scanner 100 as viewed from the Z-axis direction. A light-emitting element (10) and a photovoltaic element (11) are disposed between the rotating part (3) and the fixed part (4) surrounding it so as 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) is converted into electrical energy by the photovoltaic element (11), and as described below, it is possible to supply power to the inside of the rotating part (3) in a non-contact state. 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 called 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 a curved outer circumferential part (3-1) parallel to the Z axis and an outer surface part (3-2) consisting of a plane perpendicular to the Z axis. In this embodiment, the photovoltaic element (11) is arranged all around along the curved surface of the outer circumferential part (3-1). For this reason, the photovoltaic element (11) may be a photovoltaic element that is easily curved, for example, a sheet-like photovoltaic element using a halide-based perovskite crystal or a pyrite-based compound as a light absorbing semiconductor, which is curved. The photovoltaic element (11) is not limited to this, and a plurality of rectangular photovoltaic elements may be arranged on the outer circumferential part (3-1) so as to be parallel to the Z axis, as described later.

[0019] In contrast, the light-emitting element (10) is arranged along the fixing part (4) so ​​as to face the photovoltaic element (11). More specifically, the fixing part 4 is composed of a curved inner circumferential part (4-1) parallel to the Z axis and an inner surface part (4-2) consisting of a plane perpendicular to the Z axis. That is, in this embodiment, the light-emitting element (10) is arranged along the inner circumferential part (4-1) so as to face the photovoltaic element (11). In this way, the light-emitting element (10) and the photovoltaic element (11) can be arranged in close contact with each other, for example, at an interval of about 1 mm to 1 cm, so that energy loss due to photoelectric conversion can be minimized. In addition, since artificial light such as LED or laser light is used for the light-emitting element (10), it is easy to match the emission wavelength to the wavelength at which the photovoltaic element (11) exhibits the highest photoelectric conversion efficiency.

[0020] Modifications 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) illustrates three examples of the case where the light-emitting element (10) is arranged along the inner circumferential portion (4-1). The structure shown in FIG. 2(a) (1) is a curved sheet-like light-emitting element (10-1), and the strip-like light-emitting element (10-1) is attached to the inner circumferential portion of the fixed portion 4. For the light-emitting element (10-1), for example, a surface-emitting LED or other thin-film light-emitting element can be used. As shown in the partially enlarged view seen from the Z-axis direction, the strip-like light-emitting element (10-1) does not need to be completely integrally formed, and the joint, i.e., the non-light-emitting portion, may remain as shown. Note that a light-emitting element drive control circuit (12) for controlling the light-emitting element (10-1) is built into the fixed portion 4. The same applies to the modifications (2) and (3) of FIG. 2(a) described below.

[0021] The structure shown in FIG. 2(a)(2) is characterized in 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 across the Z-axis as shown by the dashed line. By selecting high-luminance light-emitting elements as the light-emitting elements (10-2), it is not necessary to completely cover the entire inner circumference of the fixed part 4 with the light-emitting elements (10-2). Examples of high-luminance, high-efficiency light-emitting elements include low-pressure or high-pressure sodium lamps. In addition, since the photovoltaic element (11) on the rotating part (3) is often rotating when the light-emitting element (10-2) starts to emit light, there is little concern about partial deterioration or burn-in of the photovoltaic element (11).

[0022] The structure shown in (3) of Fig. 2(a) is one in which light-emitting elements (10-3) consisting of a large number of micro LEDs or the like arranged in an array are attached to a part or the entire inner circumference of the fixed part 4. As shown in a partially enlarged view, the light-emitting elements (10-3) are arranged in an array, and light-emitting elements with different emission wavelengths, different emission intensities, etc. can be combined in vertical columns, horizontal rows, or adjacent light-emitting parts.

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

[0024] In the structure shown in (2) of Fig. 2(b), rectangular photovoltaic elements (11-2) are arranged in strips on the outer circumference (3-1) with their long sides parallel to the Z-axis, so as to surround the entire outer circumference. With this structure, even photovoltaic elements that are difficult to bend, such as silicon-based photovoltaic elements formed on a glass substrate, can be approximately surrounded along the outer circumference.

[0025] The structure shown in Fig. 2(b)(3) has a large number of photovoltaic elements (11-3) arranged in an array attached to a part or the entire inner circumference of the rotating part 3. As shown in a 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 example, in vertical columns, horizontal rows, or for adjacent power generating cells.

[0026] Any of the modified examples of the fixed part (4) shown in Figs. 2(a)(1) to (3) can be combined with any of the modified examples of the rotating part 3 shown in Figs. 2(b)(1) to (3).

[0027] Other modified examples of the structure relating to the rotating part (3) or the rotating part (3) and the fixed part (4) that are configured other than the light-emitting element (10) and the photovoltaic element (11) will be described below with reference to FIG. 2(c). In the structure shown in FIG. 2(c)(1), a slip ring, i.e., a ring-shaped electrode 14f, is arranged on the side part (3-2 in FIG. 1(c)) of the rotating part 3. On the other hand, a convex electrode terminal 14m that electrically connects with the electrode 14f is arranged on the inner side part (corresponding to 4-2 in FIG. 1(c)) of the fixed part 4 (not shown). As mentioned above, the slip ring structure has technical problems, but unlike the transfer of power, there are fewer disadvantages when it comes to the transfer of digital signals and the like other than the power supply line. For the transfer of digital signals, a non-contact communication means using electromagnetic waves may be used.

[0028] In the structure shown in FIG. 2(c)(2), a permanent magnet (17) is attached to the inside of the rotating part 3 so that the north and south poles alternate on the side part (3-2 in FIG. 1(c)) of the rotating part 3. On the other hand, an electromagnetic induction coil (16) is arranged along the inner side part (corresponding to 4-2 in FIG. 1(c)) of the fixed part so as to face the permanent magnet (17). An electromagnetic induction coil drive control circuit (15) is provided inside the fixed part (4). This structure constitutes a direct drive (DD) motor, so that 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 FIG. 2(c)(3), an electromagnetic induction coil (16) is attached inside the rotating part (3) to the side part (3-2 in FIG. 1(c)) of the rotating part 3, which is the opposite of FIG. 2(c)(2). On the other hand, a permanent magnet (17) is attached along the inner side part (4-2 in FIG. 1(c)) of the fixed part 4 so that its north pole and south pole alternate to face the electromagnetic induction coil (16). With this structure, the rotating part (3) is forcibly rotated by the rotating part drive motor (5) and the rotating part rotation timing belt (6), which generates an electromotive force in the electromagnetic induction coil (16), and a secondary battery such as a lithium ion battery inside the rotating part (3) can be charged via the electromagnetic induction coil drive control circuit (15). Therefore, the power supply to the rotating part (3) by the optical power supply can be assisted. In addition, the rotational kinetic energy of the rotating part (3) after the imaging process is completed is converted into electrical energy by the electromagnetic induction coil (16), and the kinetic energy can be recovered as electrical energy by charging a secondary battery inside the rotating part (3).

[0030] Other circuit configurations used in the CT device 100 will be described with reference to Fig. 3. Fig. 3(a) is a system block diagram mainly relating to the power supply system. A photovoltaic power generation element (11) and a light-emitting element (10) are connected to a system block (18), which are connected to a power bus line (19) via a photovoltaic power generation element power supply circuit (13) and a light-emitting element drive control circuit (12), respectively. In addition, a communication control system (21) and a secondary battery (22) are also added, and after being controlled to a required voltage level by a bidirectional DC-DC converter (20) or the like, the charging or discharging operation of each part is controlled.

[0031] FIG. 3(b) is a plan view for explaining components in the rotating part (3) as viewed from the Z-axis direction. The photovoltaic element (11) already described is attached to the outer periphery of the rotating part (3). In order to fluoroscopically view the subject (not shown) on the bed moving device (7) with X-rays, an X-ray beam (27) is irradiated from the X-ray generating part (25), and the transmitted X-rays are detected by the photodetector module (23). The X-ray generating part (25) is driven and controlled by the X-ray circuit (26). The photodetector module (23) performs imaging, signal processing, image recording and transmission, etc., by the photodetector signal processing, storage, and transfer circuit block (24). The rotating part (3) further includes a secondary battery (22), the power control system block (18) already described, and a communication control system (21) for transmitting and receiving control signals, imaging data, etc., to and from the outside of the rotating part (3).

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

[0033] Fig. 3(d) is a block diagram of an X-ray source (25) that irradiates an object to be examined and its power supply circuit (26). The X-ray source (25) may be a conventional X-ray tube, but an X-ray generator using carbon nanomaterials may also be used. That is, the X-ray source (25) is made up of a carbon nanomaterial electron beam generating cathode (25C) and an anode target (25A). The power supply circuit (26) is made up of a high-voltage control circuit (26-1) and a voltage boost 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] 4(a) is a side view of the CT device 200 according to the second embodiment as viewed from the X-axis direction. The difference from the CT device 100 according to the first embodiment is the structure of the rotating part (3) and fixed part (4) shown by the dashed lines, particularly the parts surrounded by B and B'. The other configurations have been explained in the CT device 100 according to the first embodiment, so they will not be explained here.

[0035] FIG. 4(b) is an enlarged cross-sectional view of the structure of the portion surrounded by B in FIG. 4(a). The rotating part (3) is composed of a curved outer circumferential part (3-1) parallel to the Z axis and an outer side surface part (3-2) consisting of a plane perpendicular to the Z axis. On the other hand, the fixed part (4) is composed of a curved inner circumferential part (4-1) parallel to the Z axis and an inner side surface part (4-2) consisting of a plane perpendicular to the Z axis. In this embodiment, unlike the first embodiment, the photovoltaic element (11) is attached to the outer side surface part (3-2) of the rotating part (3), and the light-emitting element (10) is arranged on the inner side surface part (4-2) of the fixed part (4) so ​​as to face it. Therefore, it is not necessary to curve either the photovoltaic element (11) or the light-emitting element (10). In this figure, the photovoltaic element (11) is arranged on both side surfaces of the rotating part (3), but as described later (for example, FIG. 5(f)), the photovoltaic element (11) may be arranged on only one side surface part. In this way, the light-emitting element (10) and the photovoltaic element (11) can be arranged in close proximity, for example with a distance of about 1 mm to 1 cm, so that energy loss due to photoelectric conversion can be minimized. Also, since artificial light such as an LED or laser light is used for the light-emitting element (10), it is easy to match the emission wavelength to the wavelength at which the photovoltaic element (11) exhibits the highest photoelectric conversion efficiency.

[0036] Fig. 4(c) is an example of a cross-sectional structure for explaining a structure in which a plurality of photodetector modules (23) in Fig. 3(b) are arranged continuously or at equal intervals along the inner peripheral surface (4-1) of the fixed part. Since the photodetector modules (23) are located in the fixed part, an opening (40) is formed through which the X-rays (27) that have passed through the subject pass. Since the photovoltaic element (11) is attached to the outer surface portion (3-2) of the rotating part (3) and the light-emitting element (10) is disposed on the inner surface portion (4-2) of the fixed part (4) so ​​as to face it, there is an advantage that the opening (40) can be formed in the outer peripheral surface (3-1) of the rotating part.

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

[0038] Fig. 4(e) is an enlarged view of the part surrounded by C in Fig. 4(d). The detector module (23) has a plurality of photodetection elements or pixel arrays densely arranged along the circumference of the inner peripheral surface (4-1) of the fixed part. Therefore, the photodetector signal processing, storage, and transfer circuit block (24), the photodetector module drive circuit (31), etc. described in Fig. 3(b) are arranged in the fixed part (4).

[0039] Figures 5(a) and 5(b) are plan views seen from the Z-axis direction to explain 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), as explained in Figure 2(b)(1), the sheet-like photovoltaic element (11) is formed into a ring shape. Unlike the case of Figure 2(b)(1), there is no need to curve it, but there is an advantage in that it is easy to create a photovoltaic element processed into a ring shape.

[0040] Fig. 5(b) shows a structure in which multiple rectangular elements are arranged at equal intervals as photovoltaic elements (11) on the side surface (3-2) of the rotating part (3). A widely used photovoltaic element, i.e., a solar panel, can be used, but it is difficult to completely cover the side surface (3-2). For this reason, the shape of the light-emitting element (10) and the shape of the photovoltaic element (11) are almost the same as that of the light-emitting element (10) as described in Fig. 5(d) below, and the light-emitting element (10) emits light only when the light-emitting element (10) and the photovoltaic element (11) face each other, thereby reducing energy loss.

[0041] Fig. 5(c) shows a structure in which a sheet-like light-emitting element (10) is formed into a circular ring shape as explained in Fig. 2(a)(1). Unlike the case of Fig. 2(a)(1), there is no need to curve the light-emitting element, and this has the advantage that the light-emitting element processed into a circular ring shape can be created in a flat manner.

[0042] As explained in Fig. 2(a)(2), Fig. 5(d) is characterized by a structure in which discrete light-emitting elements (10) that are individual components are attached to part of the inner circumference of the fixed part 4, and an equal number of light-emitting elements (10-2) are attached to the inner surface part of the fixed part 4 at symmetrical positions across the Z axis as shown by the dashed line. By selecting high-brightness light-emitting elements as the light-emitting elements (10), it is not necessarily necessary to cover the entire inner surface part of the fixed part 4 with light-emitting elements (10). In addition, since the photovoltaic element (11) on the rotating part (3) is often rotating when the light-emitting element (10) starts to emit light, it is considered that there is little concern about partial deterioration or burn-in of the photovoltaic element (11).

[0043] Fig. 5(e) shows a modified example of the configuration including the induction coil (16) and permanent magnet (17) described in Fig. 2(c)(2). The difference from the structure in Fig. 2(c)(2) is that the induction coil (16) is located on the inner peripheral 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 also located on the outer circumference of the rotating part and on the inner peripheral surface (4-1) of the fixed part, respectively.

[0044] On the other hand, in the modified example shown in FIG. 5(f), the X-ray opening (40) is formed on the outer circumference of the rotating part (30), so that 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 both the CT device 100 according to the first embodiment and the CT device 200 according to the second embodiment, the bed on which the subject is placed is moved in the body axis (Z-axis) direction by the bed moving device 7 relative to the fixed gantry section 2. However, it is clear that the present invention can also be applied to a CT device having a structure in which the gantry section 2 moves in the body axis (Z-axis) direction while the bed on which the subject is placed is fixed. [Industrial Applicability]

[0046] The CT scanner of the present invention can be easily installed in small vehicles, airplanes, and other mobile medical devices. Furthermore, by combining it with AI and high-speed communication methods, it is expected that various abnormalities that may occur in the human body can be detected from a wide range of perspectives without being overlooked, enabling rapid and flexible medical and life-saving activities in remote areas, disaster sites, conflict zones, etc. [Explanation of symbols]

[0047] 1: central axis of rotation, 2: gantry, 3: rotating part, 4: fixed part, 5: rotating part drive motor, 6: belt for rotating part rotation, 7: bed moving device, 8: CT device drive control unit, 9: display device, 10: light emitting element, 11: photovoltaic element, 12: light emitting element drive control circuit, 13: photovoltaic element power supply circuit, 14f: contact terminal on rotating part side, 14m: convex contact terminal on 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, storage, and transfer circuit block, 25: X-ray generation unit, 26: X-ray circuit, 26-1: high voltage control circuit, 26-2: voltage boost circuit, 27: X-ray beam, 30: pixel array, 31: photodetector module drive circuit, 32: signal amplification and AD conversion circuit, 33: signal scanning control circuit, 34: digital signal processing circuit, 35: image memory, 36: bus line, 37: parallel-serial conversion circuit, 38: input / output interface, 40: X-ray aperture in rotating unit

Claims

1. A CT device comprising an annular rotating part which rotates around the body axis direction of the subject, a fixed part which surrounds the rotating part, a moving means which moves the relative positions of the subject and the fixed part in the direction of the central axis, an X-ray generating part and an X-ray circuit which drives the X-ray generating part inside the rotating part, a detector module which detects the X-ray beam emitted from the X-ray generating part inside the rotating part, a signal processing, storage and transfer circuit block which processes, stores and transfers an output signal of the detector module, and a display device which displays image data based on the output signal of the detector module, wherein a photovoltaic element using a light absorbing semiconductor is arranged on the rear side of the detector module along an outer circumferential surface which is parallel to the curved central axis of the rotating part, the output terminal of the photovoltaic element is connected to a power supply circuit which includes a rechargeable battery, and the CT device has a light emitting element on the annular inner circumferential surface of the fixed part in a position opposite the photovoltaic element.

2. A CT device as described in claim 1, in which a halide-based perovskite crystal is used as the light-absorbing semiconductor.

3. A CT device as described in claim 1, in which a pyrite-based compound is used as the light-absorbing semiconductor.

4. A CT device as described in claim 1, wherein the X-ray generating unit uses a carbon nanomaterial as a field electron emission source.

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