Intelligent power system and method for protecting x-ray tubes during power outage

Abstract

An intelligent power system and method of protecting an X-ray tube of a CT imaging system during a power failure includes monitoring a remaining amount of power from a backup power supply, the backup power supply being supplied by a UPS coupled to a PDU providing power to the CT imaging system. The X-ray tube has a liquid metal bearing rotation assembly. The system and method automatically formulate a strategy and determine where to supply the backup power remainder to prevent thermal landing of the X-ray tube liquid metal bearing rotating assembly.

Description

Technical Field

[0001] The embodiments of the subject matter disclosed herein relate to providing an intelligent power system and method for protecting X-ray tubes during power outages. Background Technology

[0002] Computed tomography (CT) imaging systems can receive power from a mains power source, such as a utility power supply. A utility power supply can be connected to a public power grid. During certain conditions, in response to power outages, grid instability, component failure, or other reasons, mains power may not be available (i.e., it may not be usable by the CT imaging system).

[0003] Before shutting down the mains power to a CT imaging system, certain components, such as the X-ray source or X-ray tube, may require cooling during downtime. Unexpected power outages can damage these components. To protect these vulnerable parts and extend their lifespan, it may be desirable to have backup power available during unexpected interruptions or power outages to provide cooling routines for these fragile components when mains power is unavailable.

[0004] Hot landing of X-ray tubes with liquid metal bearings can occur during X-ray generator testing or power outages. When the rotating assembly of the liquid metal bearing lands uncontrolled (i.e., rotation stops when the bearing is hot), there is a possibility of bearing seizure due to interruption or power loss of the X-ray tube, especially when the X-ray tube is hot. The rotating component of the bearing may fuse with the fixed component, requiring X-ray tube replacement and thus causing CT imaging system downtime. X-ray tube replacement also includes one or more calibration procedures, further extending system downtime.

[0005] Therefore, a system and method are needed to provide backup power to the X-ray tube during a main power outage or power failure, allowing the X-ray tube to cool and the rotating components of the liquid metal bearing to gradually glide to a stop. Summary of the Invention

[0006] This invention provides a more detailed description of concepts in specific embodiments. It should not be used to determine the essential features of the claimed subject matter, nor should it be used to limit the scope of the claimed subject matter.

[0007] In one aspect, a method for providing backup power to a computed tomography (CT) imaging system. The method includes: monitoring the availability of power from a main power source to the CT imaging system; providing backup power to the CT imaging system via an uninterruptible power supply (UPS); distributing the backup power from the UPS to the CT imaging system via a power distribution unit (PDU); initiating a cooling sequence for the X-ray tube of the CT imaging system; and monitoring the remaining backup power from the UPS during the cooling sequence.

[0008] In another aspect, a computed tomography (CT) imaging system includes: a gantry; an X-ray source including an X-ray generator and an X-ray tube; coupled to the gantry; a gantry controller coupled to the gantry; an X-ray controller coupled to the X-ray source; a power distribution unit (PDU) coupled to the gantry; a main power supply coupled to the PDU for supplying power to the CT imaging system; a PDU controller coupled to the PDU; and an uninterruptible power supply (UPS) coupled to the PDU for providing backup power to the CT imaging system. The PDU is configured to distribute backup power from the UPS to the CT imaging system during a main power outage. The gantry controller is configured to activate a cooling sequence for the X-ray tube during a main power outage.

[0009] In another aspect, an intelligent power system and method for protecting the X-ray tube of a CT imaging system during a power outage includes monitoring the remaining power from a backup power source supplied by a UPS connected to a PDU that powers the CT imaging system. The X-ray tube has a liquid metal bearing rotating assembly. The system and method automatically develop strategies and determine where to supply the remaining backup power to prevent thermal landing of the X-ray tube's liquid metal bearing rotating assembly. Attached Figure Description

[0010] This disclosure will be better understood by referring to the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0011] Figure 1 A drawing view of a computed tomography (CT) imaging system connected to a main power supply and other electrical components, according to one embodiment, is shown.

[0012] Figure 2 A block diagram of a CT imaging system according to one embodiment is shown.

[0013] Figure 3A block diagram of portions of other components on the rotating gantry assembly (i.e., the rotating side of the gantry) and the fixed gantry assembly (i.e., the fixed side of the gantry) of a CT imaging system according to one embodiment is shown, wherein power components and an operator console are connected.

[0014] Figure 4 A schematic diagram of a power distribution unit (PDU) according to one embodiment is shown, wherein an uninterruptible power supply (UPS) is connected to the PDU.

[0015] Figure 5 A schematic diagram of the first control circuit of a PDU according to one embodiment is shown.

[0016] Figure 6 A schematic diagram of the second control circuit of a PDU according to one embodiment is shown.

[0017] Figure 7 A flowchart is shown of a system and method according to one embodiment for controlling the switching of the backup power supply of a UPS to the CT imaging system in response to an interruption or power failure of the main power supply, and controlling the CT imaging system to return to the main power supply after the main power supply is restored.

[0018] Figure 8 A method according to one embodiment is shown, the method including a timing sequence occurring after a main power failure to control the switching of a backup power supply to a CT imaging system in response to the main power failure, so as to prevent thermal landing of the liquid metal bearings of the X-ray tube of the CT imaging system.

[0019] Figure 9 The diagram illustrates a warning message that can be displayed on the user interface when the CT imaging system is on standby power and in a shutdown process, according to one embodiment. Detailed Implementation

[0020] Embodiments of this disclosure will now be described by way of example with reference to the accompanying drawings, wherein the smart power system and method include a power distribution unit (PDU), an uninterruptible power supply (UPS), and operating software or firmware to provide backup power to certain components of a computed tomography (CT) imaging system that may be damaged due to an interruption or power failure of the main power supply. When the main power supply is interrupted or failed, the smart power system and method detect the interruption or failure and switch power from the UPS to certain components of the CT imaging system (such as the X-ray source) to protect the X-ray tube during the power failure. For example, an X-ray tube with a liquid metal bearing may be damaged during a hot landing of the liquid metal bearing. When the rotating assembly of the liquid metal bearing hot lands uncontrollably (i.e., rotation stops when the bearing is hot), there is a possibility of bearing seizure due to the interruption or loss of power to the X-ray tube, especially when the X-ray tube is hot, where the rotating component of the bearing may fuse with the fixed component of the bearing, requiring replacement of the X-ray tube. In an exemplary embodiment, this disclosure provides a system and method for strategically cooling and landing a liquid metal bearing rotating assembly of an X-ray tube during a power outage.

[0021] Refer to the attached diagram. Figure 1 This is an exemplary embodiment of a computed tomography (CT) imaging system 100 configured to image a subject (such as a patient, object, or other component). The CT imaging system 100 includes a gantry 107 having a rotating gantry assembly and a fixed (i.e., non-rotating) gantry assembly. The rotating gantry assembly includes at least one X-ray source 104 configured to face the subject 204 being imaged (see [link to documentation]). Figure 2 The rotating gantry assembly further includes at least one X-ray detector assembly 108, which is located and positioned directly opposite an X-ray source 104 on the rotating gantry assembly. The X-ray source 104 is configured to project the X-ray beam 106 toward the X-ray detector assembly 108 positioned on the opposite side of the gantry 107. The at least one X-ray detector assembly 108 may include a plurality of X-ray detector elements or sensors (not shown) arranged in an array (i.e., an X-ray detector array). Although Figure 1Only a single X-ray source 104 is shown; however, in other exemplary embodiments, multiple X-ray sources and X-ray detectors can be implemented to project multiple X-ray beams 106 toward the subject and the X-ray detectors for acquiring projected image data at different energy levels. In some embodiments, at least one X-ray source 104 can achieve dual-energy or multi-energy spectral imaging by rapidly switching the voltage potential (kVp) applied across the cathode and anode of the X-ray source. In some embodiments, the X-ray detector can be an energy integration detector (EID) or a photon counting detector (PCD) capable of distinguishing X-ray photons of different energies. In other embodiments, two sets of X-ray sources and detectors can be used to generate dual-energy projections, one set configured for low kVp and the other for high kVp. Therefore, it should be understood that the systems and methods described herein can be implemented using single-energy acquisition techniques as well as dual-energy or multi-energy acquisition techniques.

[0022] In some embodiments, the CT imaging system 100 further includes an image processor 110 configured to reconstruct an image of the target volume of the imaged subject using iterative or analytical image reconstruction methods. For example, the image processor 110 may use analytical image reconstruction methods such as filtered back projection (FBP) to reconstruct an image of the patient's target volume. As another example, the image processor 110 may use iterative image reconstruction methods such as advanced statistical iterative reconstruction (ASIR), conjugate gradient (CG), maximum likelihood expectation maximization (MLEM), model-based iterative reconstruction (MBIR), and any other iterative image reconstruction method to reconstruct an image of the subject's target volume. As further described herein, in some other embodiments, in addition to iterative image reconstruction methods, the image processor 110 may also use analytical image reconstruction methods (such as FBP).

[0023] In some CT imaging system configurations, the X-ray source projects a cone-shaped X-ray beam (i.e., cone-beam scanning), which is collimated to lie in the XYZ plane of the Cartesian coordinate system and is often referred to as the "imaging plane." The X-ray beam passes through the subject being imaged, such as a patient. After being attenuated by the subject, the X-ray beam strikes an array of X-ray detector elements. The intensity of the attenuated X-ray beam received at the X-ray detector elements depends on the attenuation of the X-rays by the subject. Each X-ray detector element in the array generates a separate electrical signal, which is a measure of the X-ray attenuation at the location of the X-ray detector element. Attenuation measurements from all X-ray detector elements are acquired individually to produce a profile of the image data.

[0024] As previously mentioned, in some CT imaging systems, the X-ray source and X-ray detector array are rotated around the subject in the imaging plane by rotating the gantry assembly, causing the angle at which the X-ray beam intersects the subject to continuously change. A set of X-ray attenuation measurements (e.g., projection data) from the X-ray detector array at a given gantry angle is called a “view.” A “scan” of the subject comprises a set of views obtained at different gantry angles or viewing angles during one rotation of the X-ray source and detectors.

[0025] Projection data is processed to reconstruct an image corresponding to a two-dimensional slice obtained from the subject, or, in some examples, to reconstruct an image corresponding to a three-dimensional (3D) rendering of the subject, the projection data includes multiple views or scans. As described above, one method for reconstructing an image from a set of projection data is known in the art as filtered back projection (FBP) technique. Transmission and emission tomography reconstruction techniques also include statistical iterative methods, such as maximum likelihood expectation maximization (MLEM) and ordered subset expectation reconstruction techniques, as well as other iterative reconstruction techniques. This method converts attenuation measurements from scans into integers called “CT numbers” or “Henness units” (HU), which are used to control the brightness of the corresponding pixels on a display device.

[0026] To reduce overall scan time, a "spiral" scan can be performed. To perform a "spiral" scan, the patient is moved while being imaged during image acquisition, and data from a predetermined number of slices is acquired simultaneously. Such systems generate a spiral from a cone-beam spiral scan. This spiral cone-beam image acquisition scan produces projection data from which an image in each predetermined slice can be reconstructed.

[0027] As used herein, the phrase "reconstructed image" is not intended to exclude embodiments of this disclosure in which data representing an image is generated rather than a visual image. Therefore, as used herein, the term "image" broadly refers to both a visual image and the data representing a visual image. However, many embodiments generate (or are configured to generate) at least one visual image.

[0028] Figure 1A CT imaging system 100 is further illustrated, which receives power from a main power source 122 (such as a utility power source supplied by the mains grid) or from an uninterruptible power supply (UPS) 124 via a power distribution unit (PDU) 120. The PDU is controlled by and electrically connected to a PDU controller 130. The main power source 122 is electrically connected to the PDU 120 and supplies three-phase AC power to the PDU. The UPS 124 is electrically connected to the PDU 120. The PDU 120 is electrically connected to the CT imaging system 100 and supplies it with both AC and high-voltage DC (HVDC) power. The UPS 124 is configured to act as a backup power supply for the CT imaging system 100 during an interruption or power failure of the main power source 122.

[0029] In one exemplary embodiment, PDU 120 may include one or more sensors configured to sense the availability of power from mains power supply 122. PDU controller 130 may be configured to receive feedback from the one or more sensors and control one or more actuators in response to the availability of power from mains power supply 122 and command signals from a rack control board located in rack 107. The one or more actuators may be actuated after a timer measures a specific time delay or delay period. In one exemplary embodiment, the one or more actuators are contactors and / or switches configured to transfer power from mains power supply 122 to UPS 124 to the CT imaging system based on the availability of power from mains power supply 122. In an exemplary embodiment, if there is a power outage or interruption from mains power supply 122, PDU controller 130 may send at least one signal to actuate at least one contactor or switch to disconnect the circuit connecting mains power supply 122 to the CT imaging system, and actuate at least one contactor or switch to close the circuit connecting UPS 124 to the CT imaging system, as will be described in more detail below.

[0030] The PDU controller 130 may include at least one printed circuit board (PCB) having multiple electronic components, wherein executable instructions are stored in the memory of at least one of the electronic components. When executed, the PDU controller 130 sends a signal to control a contactor to transfer power between the main power supply 122 and the UPS 124 to the CT imaging system based on the availability of power from the main power supply 122. Power from the main power supply 122 may be detected via a current sensor, a voltage sensor, or other type of power sensor. Feedback from the power sensor may trigger the PDU controller 130 to send a signal to actuate the connection or disconnection of a contactor or switch connected to the main power supply 122, and also, after a time delay, to actuate the disconnection or disconnection of a contactor or switch connected to the UPS 124 to switch the connection from the main power supply 122 to the UPS 124, thereby outputting the load of the PDU 120 to power the CT imaging system 100.

[0031] Figure 2 It is similar to Figure 1 This is an exemplary embodiment of a block diagram of a CT imaging system 100 and a CT imaging system 200. According to various aspects of this disclosure, the CT imaging system 200 is configured to image a subject 204. In an exemplary embodiment, the CT imaging system 200 includes an X-ray source 104 and an X-ray detector array 108 within a gantry 107 of the CT imaging system 200. The X-ray detector array 108 includes a plurality of X-ray detector elements 202 that together measure X-rays from an attenuated X-ray beam 106 after passing through the subject 204 being imaged (such as a patient) to acquire corresponding projected image data. Therefore, in an exemplary embodiment, the X-ray detector array 108 is manufactured in a multi-slice configuration including multiple rows of detector elements 202. In such a configuration, one or more additional rows of detector elements 202 may be arranged in parallel to acquire projected image data.

[0032] In some embodiments, the CT imaging system 200 is configured to traverse different angular positions around the subject 204 to acquire the desired projection data. Therefore, the gantry 107 and the components mounted thereon may be in the form of a rotating gantry assembly configured to rotate about a center of rotation 206 to acquire projection image data. As the X-ray source 104 and the X-ray detector array 108 rotate around the subject 204, the X-ray detector array 108 measures and collects data on attenuated X-rays. The data collected by the X-ray detector array 108 undergoes preprocessing. The preprocessed data is typically referred to as projection data. In some embodiments, the X-ray detector array 108 may be configured as an energy integration detector (EID) or a photon counting detector (PCD).

[0033] In an exemplary implementation, the acquired projection data can be used for Base Material Decomposition (BMD). During BMD processing, the measured projection data is converted into material density projection data. The material density projection data can be reconstructed to form a set of material density maps or images of each of the corresponding base materials, such as bone, soft tissue, and / or contrast agents. These material density maps or images can be used for volumetric rendering of the base materials, such as bone, soft tissue, and / or contrast agents, within an imaging volume.

[0034] Once reconstructed, the image reconstruction of the base material image generated by the CT imaging system 200 reveals the internal features of the subject 204 as represented by the density of the base material. Density images can be displayed to illustrate internal features. In traditional methods of diagnosing medical conditions such as disease states, radiologists, internists, or other medical practitioners can examine density images to identify certain features of interest. Such features may include lesions, tumors, size, and shape of specific anatomical structures or organs, as well as other features that should be identifiable in the image based on the skill and knowledge of an individual radiologist, internist, or other medical practitioner.

[0035] Further reference Figure 2 The CT imaging system 200 may include a controller subsystem 208 to control the operation of various components of the CT imaging system 200. The controller subsystem 208 includes an examination table controller 208 for controlling the movement of the examination table 114, an X-ray controller 210 for controlling the operation of the X-ray source 104, and a gantry controller 212 for controlling the operation and rotation of the rotating gantry assembly of the gantry 107.

[0036] The CT imaging system 200 further includes a data acquisition system (DAS) 214 configured to receive analog data from detector element 202 and convert the analog data into digital signals for subsequent processing. The data received and digitized by the DAS 214 is transmitted to a computing device 216 and / or an image reconstructor for processing. In one example, the computing device 216 may be one or more computers that store digital data in memory or are coupled to a storage device 218.

[0037] Additionally, computing device 216 is coupled to one or more of the following: table controller 226, X-ray controller 210, gantry controller 212, DAS 214, and / or image reconstructor 230, and can provide them with commands and / or parameters for system operation, such as image acquisition, data measurement and collection, and / or processing. In some embodiments, computing device 216 controls the system operation of the CT imaging system. Computing device 216 can receive operator input from a technician or operator of the CT imaging system via an operator console 220 operatively coupled to computing device 216, including commands, scan parameters, imaging or scan protocols, requests for examination, drawing data and / or viewing data and / or images. Operator console 220 may include at least one user display 232, keyboard, touchscreen, or other input device to allow a technician or operator to control the operation of the CT imaging system 200.

[0038] Although Figure 2Only one operator console 220 is shown, but more than one operator console or workstation can be connected to the CT imaging system 200, for example, to enter commands, scan parameters, imaging or scan protocols, request examinations, draw data and / or view data and / or images. Furthermore, in some embodiments, the imaging system 200 can be connected via one or more configurable wired and / or wireless networks (such as the Internet and / or VPNs, wireless telephone networks, wireless LANs, wired LANs, wireless WANs, wired WANs, etc.) to multiple monitors, printers, workstations and / or similar devices, for example, located locally or remotely within an institution or hospital or in completely different locations.

[0039] In an exemplary embodiment, the CT imaging system 200 may include or be coupled to a Picture Archiving and Communication System (PACS) 224. In another exemplary embodiment, the PACS 224 may be further coupled to a remote system (such as a radiology information system, a hospital information system (RIS / HIS)) and / or coupled to an internal or external network (not shown) to allow personnel at different locations to provide commands and parameters and / or obtain access to image data.

[0040] The computing device 216 can operate the examination table controller 226 using operator-provided and / or system-defined commands and parameters. This controller, in turn, can control the movement of the examination table 114, which may be an electrically powered table. Specifically, the examination table controller 226 can move the examination table 114 to properly position the subject 204 (such as a patient) on the table within an opening or aperture of the gantry 107 to acquire projection data corresponding to the target volume of the imaged subject 204.

[0041] As previously mentioned, the DAS214 receives and digitizes projection data acquired by detector element 202. Subsequently, an image reconstructor 230, coupled to the DAS214 and computing device 216, performs high-speed image reconstruction using the measured and digitized X-ray data. Although Figure 2 Image reconstructor 230 is shown as a separate component, but in some embodiments, image reconstructor 230 may be included within computing device 216, one or more processors, edge computers, or one or more servers, including cloud computing capabilities. As mentioned, image reconstructor 230 may not be a separate component of CT imaging system 200, and alternatively, computing device 216 may perform one or more functions of image reconstructor 230. Additionally, image reconstructor 230 may be located locally or remotely and may be operatively connected to imaging system 200 using a wired or wireless network. In another exemplary embodiment, computing resources available in a "cloud" network may be used to perform one or more functions of image reconstructor 230.

[0042] In an exemplary embodiment, image reconstructor 230 may store the reconstructed image in storage device 218. Alternatively, image reconstructor 230 may transfer the reconstructed image to computing device 216 to generate usable patient information for evaluation and diagnosis. In some embodiments, computing device 216 may transfer the reconstructed image and / or patient information to user display 232 for viewing. In some embodiments, the reconstructed image may be transferred from computing device 216 or image reconstructor 230 to storage device 218 for short-term or long-term storage.

[0043] Figure 1 The UPS124 can be used as a backup power source to supply power to the computing device 216 and its auxiliary components (e.g., operator console 220 and / or user display 232, etc.) during a main power outage or interruption. As will be described in more detail herein, Figure 1 The PDU 120 and UPS 124 are configured to supply backup power not only to the computing device 216 and its auxiliary components, but also to supply backup power to components within the rotating rack assembly (such as the X-ray source, X-ray generator, and X-ray controller) during a mains power outage or interruption. During normal operation, when the mains power is available, it is used to charge the UPS's backup power, such as multiple batteries and / or capacitors within the UPS.

[0044] Figure 3 This is a block diagram of the rotating gantry assembly 318 (i.e., the rotating side of the gantry) and the fixed gantry assembly (i.e., the fixed side of the gantry) of the gantry 107 of a CT imaging system, including other components connected to power components and an operator console. Similar to... Figure 1 As shown, a main power supply 122 (such as a utility power supply) is electrically connected to a PDU 120, which is electrically connected to a UPS 124 and a PDU controller 130. The UPS 124 is used to provide backup power during an interruption or power failure of the main power supply 122. The UPS 124 may include multiple batteries or multiple storage capacitors to store backup power, which can be used in the event of a main power interruption or power failure. The UPS 124 includes a UPS Ethernet board 302, which can communicate with a PDU control board 304 within the PDU 120 and an operator console 220. The PDU control board 304 can communicate with a rack control board 316 within a rack controller 212 and is configured to detect the availability of power from the main power supply 122.

[0045] In an exemplary embodiment, the PDU control board 304 may include sensor circuitry comprising one or more sensors for continuously monitoring the availability of the main power supply 122 to detect power interruptions or outages in real time. In an exemplary embodiment, the PDU control board 304 may be configured to receive signals from one or more sensors and, in response to the availability of power from the main power supply 122, control one or more actuators and send signals indicating the availability of power from the main power supply 122 to one or more of the operator console 220 and / or rack control board 316. These signals may be routed through and / or processed by the computing device 216.

[0046] In an exemplary embodiment, when the PDU control board 304 detects a power interruption or power failure from the main power supply 122, the PDU control board 304 automatically switches the CT imaging equipment from receiving power from the main power supply 122 to receiving power from the UPS 124 or a backup power supply, and ensures the safe landing of the X-ray tube liquid metal bearing rotating assembly. If the PDU control board 304 detects that power from the main power supply 122 has been restored, the PDU control board 304 automatically switches the CT imaging equipment back to receiving power from the main power supply and returns to normal operating conditions without input from technicians or operators.

[0047] In an exemplary embodiment, main power supply 122 is electrically connected to PDU 120. PDU 120 is electrically connected to PDU controller 130, UPS 124, and rack controller 212. When power is interrupted or lost from main power supply 122, an intelligent power system or method will automatically switch the CT imaging system power supply from main power supply 122 to backup power supply UPS 124, which will supply backup power to the CT imaging system, including operator console 220 and rack 107. Figure 3 The portion of rack 107 shown includes rack controller 212, which has rack control board 316 connected to rotating rack assembly 318 (i.e., the rotating side of the rack). Rack control board 316 is connected to X-ray controller 210. Rack control board 316 is also connected to operator console 220. Figure 3 The portion of rack 107 shown also includes a power inverter 308 connected to a rotating rack assembly 318. The rotating rack assembly 318 includes an X-ray controller 210 connected to an X-ray generator and an X-ray tube 310. The X-ray generator 312 is connected to and supplies power to the X-ray tube 310. The X-ray controller is further connected to an operator console 220. The power inverter 308 is specifically connected to the X-ray generator 312. The power inverter 308 receives DC power from a PDU 120 and converts the DC power to AC power for input to the X-ray generator 312.

[0048] During a power outage or failure of the main power supply 122, the UPS 124 provides backup power to enable the CT imaging system 100 to complete the cooling sequence of the cooling X-ray tube's liquid metal bearing, and then shut down the CT imaging system or return it to normal operation. Backup power from the UPS 124 or the main power supply is supplied to the X-ray generator 312 by the power inverter 308. The X-ray controller 210 can receive commands from the operator console 220 to open or close the rotating gantry assembly 318. For example, during the cooling operation of the X-ray tube 310, the X-ray controller 210 can receive at least one command from the operator console 220 to initiate the cooling operation of the X-ray tube by removing power from the X-ray generator 312 and the X-ray tube 310, which causes the rotating assembly of the liquid metal bearing of the X-ray tube to glide to a natural stop. In some examples, the rotating assembly of the liquid metal bearing may glide downwards for a specified period of time during the cooling sequence. Additionally or alternatively, if the remaining power of the UPS is decreasing (e.g., less than seven (7) minutes of backup power remaining), the liquid metal bearing of the rotating assembly may be forced to begin sliding downwards to a stop. Furthermore, if mains power is restored, the X-ray controller may receive at least one command or signal to return to normal operation and restore power to the X-ray generator and X-ray tube.

[0049] X-ray tube 310 requires cooling after use to prevent damage to X-ray tube components, particularly the liquid metal bearing. In the event of a power outage (e.g., power from mains power supply 122 is unavailable), a sequence for cooling the X-ray tube is initiated to allow safe cooling of the X-ray tube before completely shutting down the CT imaging system. In some examples, when the X-ray tube cooling sequence is initiated, the X-ray controller may receive one or more signals (e.g., from operator console 220) to initiate the sliding of the liquid metal bearing rotating assembly to a stop. In one such example, the signal to initiate the cooling sequence may be sent after a hardware reset. Additionally or alternatively, the signal to initiate the sliding of the liquid metal bearing rotating assembly may be sent when PDU 120 determines that UPS 124 has only a limited amount of remaining backup power. In other words, UPS Ethernet board 302 communicates with UPS 124 to inform the operator or technician of the amount of remaining backup power in UPS 124 and automatically determines how best to use the remaining backup power to protect the X-ray tube from damage.

[0050] Although the CT imaging system has been described by way of example, it should be understood that this system and method may also be useful when applied to other multimodal imaging systems with X-ray sources or X-ray tubes, such as positron emission tomography / computed tomography (PET / CT) imaging systems or single-photon emission computed tomography / computed tomography (SPECT / CT) imaging systems.

[0051] Figure 4 This is a schematic diagram of a PDU 120 according to one embodiment, which has a UPS 124 connected to the PDU 120. An embodiment of the power interface between the UPS 124 and the main power supply 122 and the PDU 120 is shown. Therefore, previously introduced components can be similarly numbered in these figures. The PDU 120 can receive three-phase AC input power from the main power supply 122, circuit breaker 402, three-phase AC power line 408, and three-phase input 404 to transformer 405. Transformer 405 may have a primary winding or three-phase input 404, a primary winding 410, and a secondary winding 430. Circuit breaker 402 may be configured to trip in response to a current exceeding 150 amps flowing through the three-phase AC power line 408.

[0052] The primary winding 410 can direct power to the rectifier 416 via wire 412, through a fuse and other electronic components. This primary winding can include a voltage higher than that of the secondary winding 430. In some examples, wire 412 may be connected to a fuse configured to interrupt the circuit in response to a current exceeding the fuse's rating. Multiple contactors KXG 415 and KSS 414 may be positioned between the primary winding 410 and the rectifier 416. The rectifier 416 may be a passive or active rectifier configured to convert alternating current (AC) to direct current (DC) at its output. The output of the rectifier 416 is connected to a high-voltage DC (HVDC) load 420, which may be connected to and supply power to components connected to the rotating frame assembly. In one example, the HVDC may be greater than 600VDC.

[0053] The secondary winding 430 directs three-phase AC power to the input 446 of the UPS 124 via wire 432 and a circuit breaker. The output 447 of the UPS 124 provides three-phase AC power to the PDU 120 and the output AC load 440 of the PDU 124. This output AC load 440 supplies power to other components of the CT imaging system, such as the operator console, power cabinet, computing equipment, etc. The three-phase AC output of the UPS can also be supplied to the PDU 120 via a circuit breaker and contactor KBK 450A to the autotransformer 406. The output of the autotransformer 406 is connected to a rectifier 417, which converts the three-phase AC input to an HVDC output. The HVDC output of the rectifier 417 can be connected to a fuse and contactor KDC 455 to output an HVDC load 420.

[0054] Figure 5 and Figure 6 It is the first control circuit of the PDU according to an implementation scheme. Figure 5 ) and the second control circuit of the PDU ( Figure 6 The first and second control circuits receive power from the AC output phase B of the UPS and 24VDC from the PDU. The input phase B of the UPS124 provides 120V to the first control circuit. Power is supplied to the first control circuit using only a single AC phase (e.g., phase B) because only one phase is needed for the first control circuit to determine if a power outage has occurred and to trigger a response to the outage. Specifically, contactor KJC 442 is the trigger for responding to a power outage, as the KJC contactor is operable to detect a power outage from the UPS mains power supply via phase B. In an alternative embodiment, power may instead come from phase A or phase C. The second control circuit is connected to the rack control board via connector J3 and signals XG_Cont and Sys_XG_Cont.

[0055] The first and second control circuits include multiple three-phase contactors KJC 442, 442A, and 442B; KBK450, 450A; KDC 455, 450A; multiple timers: DR 457, 457A; TR 456, 456A; and multiple relays R1444, 444A, 444B, 444C, and R2 454, 454A. In an exemplary example, DR 457 shuts off after a ten (10) second delay following the time when main power from mains power supply 122 becomes unavailable, KBK 450A shuts off after the XG_Cont signal, and TR456 and KDC 455 shut off one (1) second after KBK 450A shuts off. The rack control board sends the signal XG_Cont to the PDU. An example XG_Cont signal may be provided after a delay (e.g., 12.5 seconds after a power outage). This signal initiates the X-ray tube cooling sequence. The delay before the XG_Cont signal ensures that power from the main power supply 122 is unavailable for a sufficiently long period to begin the X-ray tube cooling sequence, rather than a temporary power outage or power surge.

[0056] Figure 7 This is a flowchart of a system and method, according to one embodiment, for controlling the switching of backup power supply from a UPS to a CT imaging system in response to an interruption or power failure of the main power supply, and controlling the CT imaging system to return to the main power supply after the main power supply is restored. For example, if the main power supply becomes unavailable, the system will automatically switch to backup power from the UPS. The UPS is operable to provide backup power during the X-ray tube cooling sequence, which is part of the safe shutdown of the CT imaging system and prevents damage to the X-ray tube. Executable instructions for this method can be stored in the memory of the electronic components and executed by a computing device and / or a PDU controller. The PDU controller can be configured to receive input from one or more sensors in the sensor circuitry of the PDU for continuously monitoring the availability of power from the main power supply to detect power interruptions or power failures in real time, and automatically switch to backup power from the UPS when a power interruption or power failure is detected from the main power supply.

[0057] Method 700 begins at 702, which includes a CT imaging system operating under normal conditions. Normal conditions may include receiving power from a mains power source (such as a utility power supply). Under normal conditions, all functions of the CT imaging system are available. During operation of the CT imaging system, a power outage from the mains power source may occur in step 704. In the event of a mains power outage, there is no HVDC power from the PDU to the rack in step 706. In step 708, the rack control board detects the power loss. Without power supplied to the rack, many functions of the CT imaging system are inoperable. After a certain delay (e.g., 12.5 seconds), in step 710, the rack control board may signal to the PDU control board in the PDU controller and / or the operator console to switch to backup power from the UPS to supply HVDC to the rack. The delay is to ensure that the power outage is not merely a limited power interruption or power surge that does not require the start of a cooling sequence.

[0058] When the backup HVDC power is successfully connected, in step 710, the rack control board sends a command to begin supplying power to the X-ray generator, including the X-ray controller and X-ray tube. In step 712, the X-ray tube protection mechanism is triggered to begin controlling the rotation of the liquid metal bearing assembly in the X-ray tube and initiating the X-ray tube cooling sequence. The rack control board and / or PDU control board begin monitoring for remaining backup power information from the UPS. In step 714, the rack control board and / or PDU control board determines whether there is sufficient remaining backup power in the UPS to continue the X-ray tube cooling sequence. If the rack control board and / or PDU control board determines in step 716 that there is sufficient remaining backup power in the UPS, the cooling sequence continues in step 718. During the cooling sequence, in step 720, the rack control board and / or PDU control board continue monitoring the status of the main power supply to determine whether utility power has been restored. If main power is restored before the cooling sequence of the X-ray tube's liquid metal bearing rotating assembly is completed in step 722, the rack control board and / or PDU control board will cancel the cooling sequence of the X-ray tube's liquid metal bearing rotating assembly in step 702, and the rotating assembly will return to normal operating conditions. The system is able to return to normal operating conditions without any additional action or intervention from the operator or technician.

[0059] If the main power supply 122 is not restored during the rotating assembly cooling sequence in step 718, the rack control board and / or PDU control board will check in step 724 whether the required rotating assembly cooling sequence has been completed. If the rotating assembly cooling sequence is not completed in step 724, the rack control board and / or PDU control board will continue to monitor the remaining backup power in the UPS in step 716 and monitor the status of the main power supply in step 720 until the main power is restored, thereby allowing the CT imaging system to return to normal operation or the cooling sequence to be completed. The system is able to return to normal operating conditions without any additional action or intervention from the operator or technician.

[0060] If the cooling sequence is completed in step 724, or if there is insufficient remaining backup power in the UPS to complete the cooling sequence in step 716, the rack control board and / or PDU control board initiates a controlled stop of the rotating assembly in step 726. After a few minutes, the rotating assembly stops in step 728. The rack control board and / or PDU control board continue to monitor the status of the main power supply and check whether the utility power has been restored in step 730. If the main power is restored, the system returns to normal operating conditions in step 702. If the main power is not restored, the system remains in a standby state until the UPS backup power is nearly depleted in step 732 (e.g., less than three (3) minutes remaining). When the UPS backup power is nearly depleted, the system automatically initiates a shutdown to prevent unintended damage to the CT imaging system due to the sudden power loss in step 734. Therefore, the CT imaging system is shut down in a controlled manner and is turned off in step 736. Method 700 is complete.

[0061] Figure 8 Another description of method 800 includes a timing sequence occurring after a mains power outage to control a switchover to a backup power supply from a UPS in response to the mains power outage, preventing thermal landing of the liquid metal bearing rotating assembly of the X-ray tube. Thermal landing of the liquid metal bearing rotating assembly of the X-ray tube can occur during a power outage. When the rotating assembly of the liquid metal bearing lands uncontrollably (i.e., stops rotating) due to X-ray tube wear or power loss, especially when the X-ray tube is hot, there is a possibility of bearing seizure, requiring replacement of the X-ray tube. Therefore, in the event of a power outage, it is desirable to switch backup power to the X-ray tube so that the X-ray tube can cool and the rotating assembly of the liquid metal bearing gradually slides to a stop.

[0062] In an exemplary embodiment, a method for switching power to a CT imaging system from main power to backup power from a UPS at zero (0) seconds after a main power loss is described, which detects the main power outage (i.e., the main power outage during which the PDU is not supplying power to the gantry and X-ray tube) via a gantry control board and / or a PDU control board. After a short period of time (e.g., 13 seconds), the UPS begins supplying power to the gantry and X-ray tube. The gantry control board sends a signal to begin switching power from the autonomous power source to backup power from the UPS to power the gantry. After several seconds (e.g., 15 seconds after the main power loss), HVDC power is supplied from the UPS to the gantry and X-ray tube. The gantry control board detects the power supplied by the UPS. Warning messages indicating main power loss and image reconstruction freeze may be displayed on a user display.

[0063] Approximately 70 seconds after the main power failure, the status of the rotating assembly of the liquid metal bearing of the X-ray tube is displayed on the user interface of the display, and the rotating assembly latches and continues to rotate. Shortly thereafter (e.g., approximately 75 seconds after the main power failure), the rotating assembly shutdown process (cooling sequence) is initiated. During this period, the rotating assembly of the liquid metal bearing operates at approximately 50 Hz, and the heat exchanger pump operates at 5 volts. Approximately 122 seconds after the main power failure, the scan hardware reset is completed. Approximately 217 seconds after the main power failure, the rotating assembly shutdown process (cooling sequence) has reached the point where the rotating assembly begins to slide. In some exemplary embodiments, the rotating assembly slide is initiated when the remaining time for the UPS to supply backup power is approximately seven (7) minutes or less. Approximately 543 seconds after the main power failure, the rotating assembly of the liquid metal bearing of the X-ray tube stops and ceases rotation. As the slide decelerates, the rotating assembly will naturally slide to a stop. A message indicating that the rotating assembly has stopped rotating can be displayed on the user interface display. If mains power is restored at this time, the CT imaging system will return to normal operating conditions approximately 40 minutes after the mains power failure. The CT imaging system automatically returns to normal operating conditions without any action or intervention from the operator or technician. A message indicating that the CT imaging system is in normal operating conditions and image reconstruction is not frozen can be displayed on the user interface monitor. If mains power is not restored after the rotating components stop rotating, there may be approximately 20 minutes of residual backup power in the UPS. At this time, the operator console shuts down and the UPS shuts down because there is no residual backup power.

[0064] Figure 9This is an example warning message 900 that can be displayed on the user interface display 232 when the CT imaging system is on backup power and in a shutdown process. The example warning message 900 provides information that the CT imaging system is on backup power and in a safe shutdown process. The warning message 900 may also include an estimated duration of the shutdown process and instructions for the operator or technician. Additionally or alternatively, other warning messages may be displayed on the user interface display 232, such as indications that the UPS backup power may soon be depleted and the system will shut down, as well as indications of the remaining UPS backup power, and indications that main power has been restored and normal operation can be resumed.

[0065] As used herein, elements or steps listed in the singular and beginning with the word "a" or "an" should be understood to not exclude multiple said elements or steps unless such exclusion is explicitly stated. Furthermore, reference to "an embodiment" of the invention does not exclude the existence of additional embodiments that also include the referenced features. Moreover, unless explicitly stated to the contrary, embodiments that "comprise," "include," or "have" elements or multiple elements having a particular characteristic may include additional such elements that do not have that characteristic. The terms "comprise" and "in" are used as concise linguistic equivalents to the corresponding terms "comprising" and "wherein". Furthermore, the terms "first," "second," and "third," etc., are used merely as notations and are not intended to impose numerical requirements or a particular order of position on their objects.

[0066] The methods and / or processes disclosed herein can be stored as executable instructions in non-transitory memory and can be implemented by at least one processor or control system (including at least one controller combined with various sensors, actuators, contactors, switches, and other electrical or electronic hardware). The specific methods and / or processes described herein can represent one or more of any number of processing strategies (such as event-driven, interrupt-driven, multitasking, multithreading, etc.). Therefore, the various actions, operations, and / or functions shown can be performed in the shown sequence, in parallel, or omitted in some cases. Similarly, the order of processes or steps is not necessarily necessary to achieve the features and advantages of the exemplary embodiments described herein, but is provided for ease of illustration and description. One or more of the shown actions, functions, operations, and / or steps can be repeatedly performed according to the specific strategy used. Furthermore, the actions, functions, operations, and / or steps can be graphically represented as code to be programmed into the non-transitory memory of a computer-readable storage medium in a system or processor, wherein the actions are implemented by executing instructions in a system comprising various electrical and electronic components and a combination of one or more controllers.

[0067] The embodiments shown in the accompanying drawings and described above are merely illustrative embodiments and are not intended to limit the scope of the claims, including any equivalents included within the scope of the claims. Various modifications are possible and will be apparent to those skilled in the art. Any combination of the non-mutually exclusive features described herein is intended to be within the scope of this disclosure. That is, features of the embodiments may be combined with any suitable aspect described above, and optional features of any aspect may be combined with any other suitable aspect. Similarly, features listed in dependent claims may be combined with non-mutually exclusive features of other dependent claims, particularly where dependent claims are subordinate to the same independent claim. In some jurisdictions that claim a single dependent claim, such dependent claims may have been used in practice, but this should not be construed as meaning that features in dependent claims are mutually exclusive.

Claims

1. A method for providing backup power to a computed tomography (CT) imaging system, the method comprising: Monitor the availability of power from the main power supply to the CT imaging system; Backup power is provided to the CT imaging system via an uninterruptible power supply (UPS); The backup power is distributed from the UPS to the CT imaging system via a power distribution unit (PDU); Initiate the cooling sequence for the X-ray tube of the CT imaging system; as well as During the cooling sequence, the remaining backup power from the UPS is monitored.

2. The method according to claim 1, wherein detecting a power failure of the main power supply automatically switches the power to the CT imaging system from the main power supply to a backup UPS power supply.

3. The method of claim 1, further comprising detecting power restoration from the main power supply and automatically switching power to the CT imaging system from the backup UPS power supply to the main power supply.

4. The method of claim 1, further comprising, while providing backup power to the CT imaging system, displaying an indication of the CT imaging system status and power availability on a display of an operator console connected to the CT imaging system.

5. The method of claim 3, further comprising, after automatically switching power to the CT imaging system from the backup UPS power supply to the main power supply, returning the CT imaging system to normal operating conditions.

6. The method of claim 1, further comprising determining whether the amount of remaining backup power in the UPS is sufficient to complete the cooling sequence.

7. The method of claim 6, further comprising forcing the rotating assembly of the X-ray tube to slide if the amount of remaining backup power in the UPS is insufficient to complete the cooling sequence.

8. The method of claim 1, wherein the cooling sequence comprises sending at least one signal to the X-ray controller to initiate the cooling sequence and prevent thermal landing of the X-ray tube.

9. The method of claim 1, further comprising waiting for a period of time before initiating the cooling sequence.

10. A computed tomography (CT) imaging system, the computed tomography (CT) imaging system comprising: frame; An X-ray source, comprising an X-ray generator and an X-ray tube; Connected to the rack; A rack controller, which is connected to the rack; An X-ray controller is connected to the X-ray source; A power distribution unit (PDU) is connected to the rack; Main power supply, connected to the PDU to supply power to the CT imaging system; A PDU controller is connected to the PDU; as well as An uninterruptible power supply (UPS) is connected to the PDU to provide backup power to the CT imaging system; The PDU is configured to distribute backup power from the UPS to the CT imaging system during a power outage of the main power supply; and The rack controller is configured to initiate a cooling sequence for the X-ray tube during the power outage of the main power supply.

11. The CT imaging system of claim 10, wherein the PDU controller is configured to monitor the main power supply in response to a power outage.

12. The CT imaging system of claim 11, wherein the PDU controller, upon detecting a power failure of the main power supply, automatically switches the power to the CT imaging system from the main power supply to a backup UPS power supply.

13. The CT imaging system of claim 11, wherein the PDU controller, upon detecting a power restoration from the main power supply, automatically switches power to the CT imaging system from the backup UPS power supply to the main power supply.

14. The CT imaging system of claim 10, wherein the cooling sequence includes monitoring the remaining backup power of the UPS to determine whether the remaining backup power is sufficient to complete the cooling sequence.

15. The CT imaging system of claim 14, wherein if the remaining backup power is sufficient to complete the cooling sequence, the gantry controller continues the cooling sequence.

16. The CT imaging system of claim 10, wherein the X-ray tube comprises a liquid metal bearing having a rotating assembly.

17. The CT imaging system of claim 10, wherein the PDU controller is configured to send at least one signal to the X-ray controller to initiate the cooling sequence and prevent thermal landing of the X-ray tube.

18. The CT imaging system of claim 10, wherein the gantry controller is configured to stop the CT imaging system from performing imaging scans when a power failure of the main power supply is detected.

19. The CT imaging system of claim 10, further comprising, when providing backup power to the CT imaging system, displaying an indication of the CT imaging system status and power availability on a display of an operator console connected to the CT imaging system.

20. A method for protecting the power supply of an X-ray tube in a CT imaging system during a power outage, the method comprising: Monitor the remaining power from the backup power supply, which is provided by a UPS connected to the PDU that supplies power to the CT imaging system; The X-ray tube has a liquid metal bearing rotating assembly; and The system automatically determines where to supply the remaining backup power to prevent a thermal landing of the X-ray tube liquid metal bearing rotating assembly.

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