CN113925523B

CN113925523B - State detection method and device of medical imaging system and CT imaging system detection

Info

Publication number: CN113925523B
Application number: CN202010608438.3A
Authority: CN
Inventors: 张笑妍; 何毅; 唐振江; 刘鑫
Original assignee: GE Precision Healthcare LLC
Current assignee: GE Precision Healthcare LLC
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2024-03-26
Anticipated expiration: 2040-06-29
Also published as: CN113925523A

Abstract

The present disclosure provides a method and apparatus for status detection of a medical imaging system and CT imaging system detection. A medical imaging system comprising a stationary frame and a rotating part comprising a rotating base driven by a motor, characterized in that the method comprises: a data acquisition step of acquiring a current or power signal of a motor to obtain a first signal and acquiring a signal of a sensor to obtain a second signal; a state data acquisition step of acquiring state data which is based on the first signal and the second signal and which is related to a specific state of the medical imaging system. With the state detection method and device of the present disclosure, the motor in the gantry mechanism is used as a sensor for measuring the rotational resistance moment of the rotating part, and the cost of the CT imaging system can be saved.

Description

State detection method and device of medical imaging system and CT imaging system detection

Technical Field

The present disclosure relates to a state detection method and apparatus for a medical imaging system, and more particularly to an electronic Computed Tomography (CT) imaging system having a state detection method and apparatus.

Background

CT imaging systems are now widely used in clinic due to their particular diagnostic value. Generally, CT imaging systems include a large gantry mechanism within a housing having an annular opening through which a subject can be supportably moved. The gantry mechanism includes a rotating base on which the X-ray tube and detector assembly is mounted. As the rotating base rotates and the subject moves linearly along the annular opening axis, X-ray images can be taken for subsequent analysis and diagnosis.

Typically, in addition to the X-ray tube and detector assembly, other components such as a heat exchanger, generator, etc. are mounted to the rotating base. All of these components mounted on the rotating base will rotate with the rotating base in use. Ideally, a CT imaging system is capable of obtaining satisfactorily high quality images when the rotating base can be rotated uniformly and smoothly under balanced conditions.

However, the different weights, structures and mounting locations of the various components on the rotating base can also cause imbalance in the rotating portion of the CT gantry mechanism, which can cause vibration of the entire gantry mechanism. Vibration of the gantry mechanism is detrimental to image quality, with higher vibration amplitudes producing greater image artifacts. Therefore, it is necessary to control the vibration amplitude of the stage mechanism within a certain range. For unbalance of the rotating part of the CT gantry mechanism, the gantry mechanism corrects by arranging a counterweight mechanism. Generally, the CT gantry mechanism is pre-calibrated at the factory where the CT imaging system is built and calibrated before being transported to the final installation destination. In-situ balance correction is also required to ensure accurate performance of the CT imaging system after it is transported to the installation destination, or after replacement of new components, such as replacement of the X-ray tube. However, the existing balance correction system of the gantry mechanism is complex, a plurality of sensors are required to be arranged, and the complex sensor arrangement makes the system costly, so that the existing balance correction system still needs to be improved.

Disclosure of Invention

To overcome the deficiencies in the prior art, the present disclosure proposes a method of status detection for a medical imaging system comprising a stationary frame and a rotating part comprising a rotating base driven by a motor, characterized in that the method comprises: a data acquisition step of acquiring a current or power signal of a motor to obtain a first signal; a state data acquisition step of acquiring state data which is based on the first signal and which is related to a specific state of the medical imaging system.

According to one aspect of the disclosure, the first signal comprises a current or power ripple signal that occurs once per revolution of the rotating base.

According to another aspect of the disclosure, the status data includes a magnitude and a phase angle of the first signal, the status data corresponding to a configuration of the weight mechanism on the rotating base.

According to another aspect of the present disclosure, the data acquisition step further comprises: collecting a second signal output by a sensor arranged on the fixed frame; and the status data obtaining step further comprises obtaining supplemental status data based on the second signal and related to a particular status of the medical imaging system, the supplemental status data corresponding to a configuration of the weight mechanism on the rotating base.

According to another aspect of the present disclosure, the status data acquisition step includes:

extracting a fluctuation signal which appears once every turn of the rotating base from a first signal or the second signal; and calculating an amplitude and a phase angle associated with a particular state of the medical imaging system based on the extracted fluctuation signal.

According to yet another aspect of the present disclosure, the status data acquisition step further includes: when the first signal or the second signal is obtained by sampling at equal time intervals, processing the first signal or the second signal using one of fourier transform and least square method; and processing the first signal or the second signal using a least squares method when the first signal or the second signal is obtained by sampling at different time intervals.

According to yet another aspect of the present disclosure, the method controls the motor to rotate the rotating base at a constant rotational speed, wherein the constant rotational speed is near or equal to a nominal maximum rotational speed of the rotating base, and the data acquisition step is performed under conditions in which the rotating base rotates at the constant rotational speed.

In addition, the present disclosure also provides a state detection device of a medical imaging system including a stationary frame and a rotating portion including a rotating base driven by a motor and a rotating member mounted thereon, the state detection device including: a data acquisition module configured to acquire a current or power signal of the motor to obtain a first signal; a status data acquisition module configured to acquire status data based on the first signal and related to a particular status of the medical imaging system.

According to yet another aspect of the present disclosure, the data acquisition module is further configured to acquire a second signal output by a sensor disposed on the stationary frame; and, the status data acquisition module is configured to acquire a supplemental status parameter based on the second signal and related to a particular status of the medical imaging system, the supplemental status parameter corresponding to a configuration of the weight mechanism on the rotating base.

According to yet another aspect of the disclosure, the status data acquisition module is further configured to: extracting a fluctuation signal which appears once every turn of the rotating base from the first signal or the second signal; and calculating an amplitude and a phase angle associated with a particular state of the medical imaging system based on the extracted fluctuation signal.

According to still another aspect of the present disclosure, the state detection apparatus further includes: and a motor control module configured to control the motor to rotate the rotating base of the gantry mechanism at a constant rotational speed, wherein the constant rotational speed is near or equal to a nominal maximum rotational speed of the rotating base.

According to yet another aspect of the present disclosure, the first signal may further comprise a current or power ripple signal occurring a plurality of times per revolution of the rotating base, and the second signal may further comprise a ripple signal occurring a plurality of times per revolution of the rotating base.

The present disclosure also provides a CT imaging system, comprising: a fixed frame and a rotating part including a rotating base driven by a motor and a rotating member thereon; at least one weight mechanism comprising at least one weight that is adjustable; a state detection device comprising a data acquisition module configured to acquire a current or power signal of the motor to obtain a first signal and a state data acquisition module configured to acquire state data based on the first signal and related to a particular state of the CT imaging system, the state data being indicative of an adjustment of the at least one balancing weight.

According to another aspect of the present disclosure, the CT imaging system further comprises a sensor disposed on the stationary frame. Preferably, the sensor is selected from the group consisting of an acceleration sensor, a velocity sensor and a displacement sensor, and is provided at an upper portion or a middle portion of a fixed frame of the stage mechanism, or the sensor is selected from the group consisting of a strain sensor and a piezoelectric sensor, and is provided at a lower portion of the fixed frame of the stage mechanism.

According to yet another aspect of the present disclosure, the data acquisition module further acquires signals of the sensor to obtain a second signal, the status data acquisition module further comprising acquiring a supplemental status parameter based on the second signal and related to a particular status of the CT imaging system, the supplemental status parameter corresponding to a configuration of the weight mechanism on the rotating base.

According to yet another aspect of the present disclosure, the CT imaging system further includes a first test block and a second test block, the first test block and the second test block having a predetermined weight, an installation location, respectively, and the first signal includes a fluctuation signal occurring once per rotation of the rotating base without the first test block and the second test block installed, respectively.

According to yet another aspect of the present disclosure, the rotating portion further includes an X-ray tube mounted on the rotating base, the X-ray tube being disposed at a 0 degree position about a central axis of the rotating portion about which a rotation angle between the first weight mechanism and the second weight mechanism is disposed at a position rotated by about 180 degrees with respect to the 0 degree position.

According to yet another aspect of the present disclosure, the at least one weight mechanism includes a first weight mechanism and a second weight mechanism; and the status data acquisition module is further configured to: when the first signal or the second signal is obtained by sampling at equal time intervals, processing the first signal or the second signal using one of fourier transform and least square method; processing the first signal or the second signal using a least square method when the first signal or the second signal is obtained by sampling at different time intervals; extracting a fluctuation signal which appears once every revolution of the rotating base from the processed first signal and the processed second signal; calculating an amplitude and a phase angle associated with a particular state of the CT imaging system based on the extracted fluctuation signal; and calculating a new configuration of the first weight mechanism and the second weight mechanism provided at different positions on the rotating portion of the gantry mechanism according to the magnitude and the phase angle when the calculated magnitude does not satisfy the preset value.

By adopting the detection state detection method disclosed by the invention, the original motor of the rack mechanism in the CT imaging system is used for realizing state monitoring of the system. Particularly, in the process of monitoring the balance state, the motor replaces a sensor specially designed for measuring the rotation resistance moment of the rack mechanism, so that the cost of the CT imaging system can be saved. Further, since the motor can reflect the magnitude of the resistance moment more accurately, balance correction with high accuracy can be achieved.

Drawings

The disclosure may be better understood by describing exemplary embodiments of the disclosure in conjunction with the following drawings, in which like reference numerals are used to designate like or similar parts throughout the several views, and wherein:

FIG. 1 illustrates a perspective view of a conventional CT imaging system;

FIG. 2 illustrates a front view of a CT gantry mechanism with a cover of the CT gantry mechanism removed to show internal structure thereof, in accordance with a preferred embodiment of the present disclosure;

FIG. 3 illustrates an exploded perspective view of a first weight mechanism for use in a CT gantry mechanism in accordance with a preferred embodiment of the present disclosure;

FIG. 4 illustrates an exploded perspective view of a second counter weight mechanism for use in a CT gantry mechanism according to a preferred embodiment of the present disclosure;

FIG. 5 shows a schematic diagram of a time domain sampled signal in accordance with a preferred embodiment of the present disclosure;

FIG. 6 shows a schematic diagram of a processed frequency domain signal in accordance with a preferred embodiment of the present disclosure;

FIGS. 7A and 7B are flowcharts illustrating a two-plane balancing method according to a preferred embodiment of the present disclosure;

FIGS. 8A and 8B illustrate a flow chart of a static balancing method according to a preferred embodiment of the present disclosure; and

fig. 9 shows a schematic block diagram of a control device according to a preferred embodiment of the present disclosure.

List of reference numerals

10 CT imaging system

12. Scanning bed

20. Bench mechanism

21. Bench opening

30. Rotary base

31. First counterweight mechanism

311. First counterweight base

312. First balancing weight

32. Second counterweight mechanism

321. Second counterweight base

322. Second balancing weight

323. Gasket

35. Detector assembly

36 X-ray tube

40. Fixed frame

50. Motor with a motor housing

51. Motor controller

60. Sensor for detecting a position of a body

100. Flow chart

200. Flow chart

400. State detection device

410. Data acquisition module

420. Status data processing module

450. Motor control module

Detailed Description

In the following, specific embodiments of the present disclosure will be described, and it should be noted that in the course of the detailed description of these embodiments, it is not possible in the present specification to describe all features of an actual embodiment in detail for the sake of brevity. It should be appreciated that in the actual implementation of any of the implementations, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that while such a development effort might be complex and lengthy, it would nevertheless be a routine undertaking of design, fabrication, or manufacture for those of ordinary skill having the benefit of this disclosure, and thus should not be construed as having the benefit of this disclosure.

Unless defined otherwise, technical or scientific terms used in the claims and specification should be given the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first," "second," and the like in the description and in the claims, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, is intended to mean that elements or items that are immediately preceding the word "comprising" or "comprising", are included in the word "comprising" or "comprising", and equivalents thereof, without excluding other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, nor to direct or indirect connections.

Fig. 1 illustrates a conventional CT imaging system, generally indicated by reference numeral 10. The CT imaging system 10 generally includes a scan bed 12 and a gantry mechanism 20 that position a subject. The stage opening 21 of the stage mechanism 20 is formed in the X-Y plane and is rotatable about the Z axis. An X-ray generating device 36, such as an X-ray tube, and a detector assembly 35 are located on the gantry mechanism 20 opposite each other. The imaging system 10 is capable of taking X-ray images of a subject as the scan bed 12 moves in whole or in part in the Z-axis direction through the gantry opening 21 of the gantry mechanism 20.

Fig. 2 illustrates a front view of a gantry mechanism 20 to which the methods of the present disclosure are applicable. The cover of the gantry mechanism 20 has been removed for clarity to show some of the major components inside the gantry mechanism 20. As shown in fig. 2, the stage mechanism 20 includes a fixed frame 40 and a rotating portion capable of rotating about a Z-axis relative to the fixed frame 40, the rotating portion including a rotating base 30 and a plurality of components mounted thereon. The rotational fit between the stationary frame 40 and the rotating base 30 may be achieved by bearings (not shown), for example. The bearing comprises a moving coil and a static coil, and the moving coil and the static coil are centered around the Z axis. The rotating base 30 is mounted to the moving coil of the bearing, and the stationary coil of the bearing is connected to the stationary frame 40 such that relative movement between the stationary and moving coils of the bearing effects relative movement between the rotating base 30 and the stationary frame 40.

The components mounted for rotation with the rotating base 30 include an X-ray tube 36 for generating X-rays and a detector assembly 35 for receiving X-rays for detection. Conventionally, power is fed through slip rings and brushes to these power requiring components on the rotating base 30. As shown in fig. 1, an X-ray tube 36 is disposed on the rotating base 30 opposite the detector assembly 35. The X-ray tube 36 projects an X-ray beam, and the detector assembly 35 is capable of sensing the beam projected thereto through the subject and generating a corresponding electrical signal based on the intensity of the received beam. For ease of description, the position of the X-ray tube 36 on the rotating base 30 shown in fig. 2, the twelve o' clock position, is defined as the 0 degree position, with degrees being measured in a counter-clockwise rotation about the Z-axis.

A motor 50 for providing a driving force to the rotating base 30 is fixedly installed on the fixed frame 40. The driving force output from the motor 50 is transmitted to the rotating base 30 through a transmission mechanism such as a belt, a chain, a gear, or the like, so that the rotating base 30 rotates on the fixed frame 40 with a controlled rotation speed centered on the Z axis. In a preferred embodiment, as shown in fig. 2, the motor 50 is installed at the lower right side of the fixed frame 40. The motor 50 is furthermore provided with an associated motor controller 51 for controlling the operation of the motor 50. The motor controller 51 may be provided adjacent to the motor 50 or may be integrated with the motor 50. By means of the built-in control logic of the motor controller 51, the motor controller 51 is able to control the motor 50 to drive the rotating base 30 to rotate at an accelerated, decelerated and constant rotational speed.

During use of the CT imaging system, the rotating portion of gantry mechanism 20 rotates under the drive of rotating base 30. It has been found that by acquiring and obtaining current or power signals of the motor 50, status data relating to a specific status of the CT imaging system, in particular the gantry mechanism, can be obtained. Thus, the specific state of the gantry mechanism in the CT imaging system can be detected. In some embodiments, the particular state may be an unbalanced state of the gantry mechanism. In other embodiments, the particular state may be a state indicative of one or more faults of the gantry mechanism.

Specifically, the signal that can be extracted from the current or power signal of the motor 50 includes a signal that occurs a single or multiple times per revolution of the rotating base 30. Such as a signal that appears once per revolution of the rotating base 30, a signal that appears twice per revolution of the rotating base 30, a signal that appears three times per revolution of the rotating base 30, etc. The signal given by the motor 50 that a particular number of occurrences of rotation of the rotating base 30 per revolution may correspond to a particular physical quantity associated with the gantry mechanism 20 of the CT imaging system. These signals may be used to detect a particular state of the gantry mechanism and adjust accordingly, depending on the particular correspondence.

In some embodiments, the ripple signal provided by the motor 50 that occurs once per revolution of the rotating base 30 can reflect an imbalance in the rotating portion of the gantry mechanism 20. In other embodiments, the signal provided by the motor 50 that the rotating base 30 is present twice per revolution may reflect a failure of the gantry mechanism 20, and thus, the failure of the gantry mechanism may be detected using the signal provided by the motor 50 and an alarm may be selected based on the detection result.

It is particularly advantageous that the signal extracted from the current or power signal of the motor 50 that occurs once per revolution of the rotating base 30 can reflect an imbalance in the rotating portion of the gantry mechanism 20. Thus, this signal provided by the motor 50 may be used in a method and system for detecting an imbalance condition of the gantry mechanism 20, and the condition detection method and apparatus may further include means for correcting the detected imbalance of the gantry mechanism 20.

Hereinafter, a method and system relating to detection and correction of an imbalance condition of the gantry mechanism 20 will be described exemplarily.

When the CT gantry mechanism 20 is in operation, the weight, structure, and position of the various components disposed on the rotating base 30 often cause an imbalance in the rotating portion that can cause the entire gantry mechanism 20 to vibrate at a frequency of one occurrence of each revolution of the rotating base 30. Unacceptable vibration artifacts may be created when the vibration increases beyond a certain threshold, thereby affecting imaging quality. The balance correction of the rotating portion of the gantry mechanism 20 generally includes a static balance correction and a dynamic balance correction. In particular, a static imbalance may occur in the rotating portion of the gantry mechanism 20, meaning that the overall center of gravity of the rotating portion is not coincident with the axis of rotation. The static balance correction is mainly achieved by increasing or decreasing the number of weights in the first and second weight mechanisms 31, 32 so that the center of gravity of the rotating portion coincides with the rotation axis thereof. On the other hand, a dynamic unbalance, that is, an unbalance caused by moment generation in the Z direction due to uneven weight distribution of the rotating portion, also occurs in the rotating portion of the stage mechanism 20. The dynamic balance correction is mainly achieved by the movement and adjustment of the weights in the first and second weight mechanisms 31, 32 in the Z-axis direction to cancel out the unbalanced moment. To overcome the imbalance described above, a balance correction system is incorporated into the CT gantry mechanism 20, as shown in FIG. 2. The balance correction system comprises a weight mechanism located on the rotating base 30 of the gantry mechanism 20, in particular a first weight mechanism 31 in a first position and a second weight mechanism 32 in a second position, the first and second positions being two different circumferential positions around the axis of rotation of the rotating base 30. Preferably the rotation angles between the two weight mechanisms 31, 32 are different by 80-120 degrees, and ideally the rotation angles of the two weight mechanisms 31, 32 are different by about 90 degrees. In the preferred embodiment shown in fig. 2, with the X-ray tube 36 positioned at a 0 degree position, the first weight mechanism 31 is positioned at a first position rotated about the Z-axis counterclockwise about 66 degrees relative to the 0 degree position, and the second weight mechanism 32 is rotated about 180 degrees about the Z-axis relative to the 0 degree position. It will be appreciated that the position of the two weight mechanisms may vary for different models of CT imaging systems due to differences in the components and conditional constraints on the rotating base 30 of the various CT imaging systems.

Fig. 3 illustrates an exploded perspective view of the first weight mechanism 31. The first weight mechanism 31 has a plurality of first weights 312, and the first weights 312 are optionally mounted to a first weight base 311. These weights 312 each have a different weight and may include a heavier weight and a lighter weight, which may be made of, for example, steel and have different thicknesses and shapes to achieve a variety of different weight combinations, and may be made of other specific gravity materials such as aluminum. The weight base 311 is provided with a plurality of holes in rows in the Z-axis direction so that the position of the weight 312 is adjustable in the Z-axis direction. It will be appreciated that the selection of the number of weights and the weight of each weight on the weight base 311 will affect the static balance of the rotating portion of the gantry mechanism 20, while the mounting position of the selected weight 312 on the base along the Z-axis will affect the dynamic balance of the rotating portion of the gantry mechanism 20.

Fig. 4 illustrates an exploded perspective view of the second weight mechanism 32. The second weight mechanism 32 includes a plurality of second weights 322 and a plurality of shims 323, which are mounted on the second weight base 321 by a firmware rod. The second weight 322 is typically made of a heavier weight material, such as steel, and the spacer 323 is typically made of a lighter weight material, such as aluminum. The second balancing weights 322 are each formed to have the same or different weight and shape, and the shims 323 may also be formed to have the same or different thickness and shape, and the position of the second balancing weights 322 in the Z-axis direction may be adjusted as needed by selecting different numbers and/or thicknesses of shims 323. In this way, the static or dynamic balance of the rotating portion of the CT gantry mechanism 20 can be adjusted by various selections and combinations of the second weight 322 and the spacer 323 of the second weight mechanism 32.

The CT imaging system 10 will typically be pre-calibrated prior to shipment, i.e., the first and second weight mechanisms 31, 32 will be pre-set to maintain the amount of imbalance of the gantry mechanism 20 below a pre-set value. When the CT imaging system 10 is transported to the installation destination for reassembly, the balance of the original calibration of the system 10 may be compromised for a variety of reasons, such as replacement of rotating components for repair. Therefore, it is necessary to perform recalibration, that is, balance correction operation on the first and second weight mechanisms 31, 32 again.

In accordance with a particular aspect of the present disclosure, a method and apparatus for detecting the condition of a gantry mechanism in a CT imaging system utilizes a motor 50 that drives a rotating base 30 of the gantry mechanism 20. Specifically, the method and system according to the present disclosure employ the motor 50 as a means for providing an imbalance signal. When the motor 50 provides driving force to drive the rotating base 30 to rotate at a uniform speed, a change in resistance moment due to unbalance of the rotating part occurs on the gantry mechanism 20, and the driving force output by the motor 50 is used for overcoming the resistance moment, and the current or power of the motor 50 is used for responding to the change in resistance moment. The inventors have found that the corresponding change in current or power of the motor 50 can reflect the unbalance in the X-Y plane of the gantry mechanism instantaneously, and have thus proposed using the motor 50 as a source of unbalance signals, providing the balance correction system with a measurement signal regarding the unbalance state by analyzing the current or power of the motor 50.

Since in the gantry mechanism 20 the imbalance appears to occur once per revolution of the rotating base, a fluctuating signal of the current or power of the motor 50 that occurs once per revolution of the rotating base 30 will be able to reflect the imbalance of the rotating portion of the gantry mechanism 20. Accordingly, the gantry mechanism 20 may be provided with a control device for acquiring and extracting a signal that occurs once per revolution of the rotating base from the current or power signal of the motor 50, and using the signal for achieving the balance correction of the gantry mechanism 20.

Advantageously, the initial signal acquisition from the motor 50 may be by means of an existing motor controller 51. The control means of the gantry mechanism 20 can be software, hardware, firmware, or a combination thereof for accomplishing the collection, processing, and extraction of the motor 50 signals. In some embodiments, the control device of the gantry mechanism 20 can be part of the motor controller 51. In other embodiments, the control device of the gantry mechanism 20 can be a separate device from the motor controller 51. In other alternative embodiments, the motor controller may be integrated as part of the control device of the gantry mechanism 20 as the motor control module 450, as shown in fig. 9.

Typically, the current or power signal of the motor 50 may be acquired at a fixed sampling frequency or at fixed time intervals.

Fig. 5 exemplarily shows a time domain signal obtained by the control apparatus sampling the motor 50 current or power collected from the motor 50 at set time intervals. The control device is configured to convert the collected signal into a frequency domain signal by fourier transformation or least square method, as illustrated in fig. 6, and then extract the signal that appears once per revolution of the rotating base 30 from the frequency domain signal. Since the extracted signal is due to imbalance of the rotating part, it can be used for balance correction. For example, if the exemplary rotating base 30 rotates two turns a second, then the signal that occurs twice a second in the frequency domain signal is due to the imbalance of the gantry mechanism 20, which is extracted for use in the balance correction of the CT gantry mechanism 20.

On the other hand, in order to detect a specific state of the gantry mechanism in the CT imaging system, as shown in fig. 2, the gantry mechanism 20 may be further provided with one or more sensors 60 on its fixed frame 40. The sensor 60 serves as a detection means for acquiring state data of the gantry mechanism 20, while serving as a means of the CT balance system for providing signals related to the imbalance state in the Z-axis direction, thereby providing supplemental state data in addition to that which can be provided by the motor 50. In a preferred embodiment, the sensor 60 may be disposed on the left leg of the stationary frame 40.

In a preferred embodiment, the sensor 60 is a strain gauge sensor. In other alternative embodiments, the sensor 60 may also be a speed sensor, an acceleration sensor, a piezoelectric sensor, a displacement sensor, or other sensor capable of measuring the Z-axis imbalance of the gantry mechanism 20. The sensor can be arranged at a corresponding detection signal sensitive position on the rack mechanism according to the characteristics of the sensor. For example, the acceleration sensor, the speed sensor, and the displacement sensor may be provided at an upper portion or a middle portion of a fixed frame of the stage mechanism; the strain sensor and the piezoelectric sensor may be disposed at a lower portion of a fixed frame of the stage mechanism. The sensor 60 may be arranged to detect deformations and/or vibrations due to unbalance of the gantry mechanism 20 in the Z-axis direction.

Likewise, the signal that can be extracted from the signal output from the sensor 60 includes a signal that appears a single or multiple times per revolution of the rotating base 30. Such as a signal that appears once per revolution of the rotating base 30, a signal that appears twice per revolution of the rotating base 30, a signal that appears three times per revolution of the rotating base 30, etc. The signal given by the sensor 60 that a particular number of occurrences of the rotating base 30 per revolution may correspond to a particular physical quantity associated with the gantry mechanism 20 of the CT imaging system. Depending on the particular correspondence, these signals may be used to detect the particular correspondence of the gantry mechanism and adjust accordingly. The signal of the sensor 60 output that the rotating base 30 appears once per revolution will be able to reflect the imbalance of the rotating part of the gantry mechanism 20, and the control device collects and extracts the signal of the rotating base that appears once per revolution and uses this signal for achieving the balance correction of the gantry mechanism 20. The signaling, processing and extraction of the signals may be implemented by software, hardware, firmware or a combination thereof in the control means of the gantry mechanism 20.

In combination with the signals from the motor 50 and the sensor 60, a two-plane balancing method may be performed on the CT gantry mechanism 20. The process of two-plane balancing may include a data acquisition step in which current or power signals of the motor 50 and signals output by the sensor 60 are acquired, and a state data acquisition step in which the signals from the motor 50 and the sensor 60 are subsequently processed to obtain state data related to the two-plane balance state of the CT gantry mechanism. The obtained state data can correspond to the arrangement of the weight mechanism on the swivel base 30, and the weight mechanism can be adjusted based on the balance calculation result of the state data.

In a preferred embodiment, first, a two-plane balancing method performs a testing step of reference test data or signals. The motor 50 is caused to rotate the rotating base 30, advantageously by means of the control logic of the motor controller 51, to bring the rotational speed of the rotating base 30 to or near a constant value. In the data acquisition step, the measured value of the sensor 60, the current or power signal of the motor 50, the sampling time, and the rotational phase angle of the rotating base 30 are acquired by the control device.

The signals acquired from both the motor 50 and the sensor 60 generally need to be processed in order to extract the desired surge signal. When the signal is obtained by sampling at equal time intervals, the sampled signal may be processed by fourier transform or least square method; when the signal is obtained by sampling at different time intervals, the sampled signal may be processed by a least square method. The sampled signal of the current or power of the motor 50 can be processed by the control device, from which the signal occurring once per revolution is extracted and expressed as a vector signal X ₀ . At the same time, the sampling signal of the sensor 60 is processed to extract the fluctuation signal which appears once every revolution and express it as a vector signal Z ₀ . Vector signal X ₀ And vector signal Z ₀ Each comprising an amplitude and a phase angle。

Next, a test step of test block a was performed. The weight and position of test block a are preset. For example, test block a is mounted at an angle of about 180 degrees to which second counter weight mechanism 32 is disposed. After the test block a is installed, the gantry mechanism 20 is activated and the rotating base 30 begins to rotate relative to the stationary frame 40, and when the rotating base 30 reaches or approaches a constant rotational speed, a current or power signal is collected from the motor 50. The signal can be processed by the control means, from which a wave signal occurring once per revolution of the rotating part of the gantry mechanism 20 is extracted and expressed as a vector signal X _a . At the same time, the signal of the sensor 60 is processed, from which a fluctuation signal occurring once per revolution is extracted and expressed as a vector signal Z _a . Vector signal X _a And vector signal Z _a Both amplitude and phase angle.

Then, the test block A was removed, and the test block B was mounted for another test. Similarly, the weight and position of test block B are preset, but the position of test block B in the X, Y and Z-axis directions is different from that of test block a. For example, the test block B is disposed at a position rotated clockwise by about 30 degrees with respect to the 0 degree position, and the test block B is offset back and forth with respect to the test block a in the Z axis direction. After the test block B is mounted, the CT gantry mechanism 20 is again activated, the motor 50 drives the rotating base 30 to rotate, and when the rotating base 30 reaches a constant rotational speed, a current or power signal is collected from the motor 50. The signal which occurs once per revolution can be extracted from the signal obtained from the motor 50 by the control device and expressed as a vector signal X _b . At the same time, the signal of the sensor 60 is processed, from which the signal occurring once per revolution is extracted and expressed as a vector signal Z _b . Vector signal X _b And vector signal Z _b Both amplitude and phase angle.

After all three test data have been acquired, the status data can be correlated to the configuration of the weight mechanism on the swivel base for balance correction. Specifically, the following matrix formula (sensitivity matrix [ c ]) can be determined from these vectors.

P _af ＝m _a *R _a ＜θ _a P _bf ＝m _b *R _b ＜θ _b (4)

P _a ＝P _1f *R _a ＜α _a P _b ＝P _2f *R _b ＜α _b (5)

In the above formula, X ₀ For vector signals from motor 50 in the benchmarking test step, Z ₀ For vector signals from the sensor 60 in the benchmarking step, X _a For the vector signal Z from the motor 50 in the test step of test block A _a For the vector signal X from the sensor 60 in the test step of test block A _b For the vector signal Z from the motor 50 in the test step of test block B _a Is the vector signal from sensor 60 during the test step of test block B.

Based on the vector signal X measured in the above three steps ₀ 、Z ₀ 、X _a 、Z _a 、X _b 、Z _b By means of the sensitivity matrix [ c ]]Can be solved to obtain P _a And P _b 。P _a And P _b Two initial unbalance amounts at the rotation part of the CT gantry mechanism 20 in the initial state are shown, respectively.

The sensitivity matrix c may be stored and reused later. The sensitivity matrix is a function of the gantry mechanism and does not change over time. For example, when re-used to solve a new configuration of a set of weight mechanisms, test blocks a and B need not be connected again, thereby saving time required for balancing operations.

When P _a And P _b After the determination, P can be determined by a calculation program and algorithm including the following formula _a And P _b The resulting imbalance is corrected. Since the CT gantry mechanism 20 includes a first weight mechanism 31 and a second weight mechanism 32 that are positioned at two different angular positions, then a specific new configuration for each weight mechanism needs to be calculated to enable the balance correction of the forces and moments generated by the two weight mechanisms in combination.

F _x-add ＝I _m (P _a )+I _m (P _b )

F _y-add ＝R _e (P _a )+R _e (P _b ) (6)

D _x-add ＝R _e (P _a )*(Z _po -Z _pa )+R _e (P _b )*(Z _po -Z _pb )

D _y-add ＝I _m (P _a )*(Z _po -Z _pa )+I _m (P _b )*(Z _po -Z _pb )

In the above formulas (6) and (7), F _x-add 、F _y-add 、D _x-add 、D _y-add Respectively denoted by P _a And P _b Induced forces and moments, F _x-initial 、F _y-initial 、D _x-initial 、D _y-initial Representing the forces and moments caused by the initial arrangement of the first 31 and second 32 counterweight mechanisms, respectively, and F _x-new 、F _y-new 、D _x-new 、D _y-new Representing the forces and moments caused by the new configuration of the first 31 and second 32 weight mechanisms, respectively. I _m Representing vector P in brackets _a Or P _b Imaginary part of R _e Representing vector P in brackets _a Or P _b The real part of Z _pa Coordinate value of the center of gravity of the test block A in the Z direction in the coordinate system is represented by Z _pb Coordinate value of the center of gravity of the test block B in the Z direction in the coordinate system, Z _po Coordinate values representing the Z direction in the coordinate system of the plane in which the center of mass position of the rotating portion lies will not change if a mass is added to this plane. Wherein F is _x-add 、F _y-add 、D _x-add 、D _y-add Can be found from equation (6).

F _x-new 、F _y-new 、D _x-new 、D _y-new After the values of (2) are determined by the formula (7), then, the new configurations of the first weight mechanism 31 and the second weight mechanism 32 are further calculated as follows.

In the above formula F _x-1-new 、F _y-1-new 、D _x-1-new 、D _y-1-new The total unbalance values, F, respectively, caused by the new configuration to be set of the first weight mechanism 31 _x-2-new 、F _y-2-new 、D _x-2-new 、D _y-2-new The total imbalance amounts caused by the new configuration to be set by the second weight mechanism 32, respectively. ΔF (delta F) _x And DeltaF _y Respectively, the static unbalance in X and Y directions, and DeltaD _x And DeltaD _y Respectively refer to the dynamic unbalance amount, deltaS, of X and Y directions _t Representing the total static imbalance tolerance allowed by the CT system, and ΔD _t Representing the total dynamic imbalance tolerance allowed by the CT system.

The appropriate balancing weights and the corresponding Z-axis positions of the first balancing mechanism 31 and the second balancing mechanism 32 can be obtained through solving by a solving algorithm. Subsequently, the first weight mechanism 31 and the second weight mechanism 32 mounted on the CT system in place are reset according to the result of the calculation.

The calculation algorithm may be performed by software in the control means of the gantry mechanism 20 and the new configuration of the weight mechanisms 31 and 32 may be output to the user by means of a display or printer, etc., so that the user can conveniently complete the adjustment of the weight mechanisms 31 and 32 at the installation site.

Fig. 7A and 7B illustrate a flow chart 100 of a two-plane balancing method according to a preferred embodiment of the present disclosure. The logic of the associated flowchart 100 may be implemented by a control device of the CT gantry mechanism 20 according to the present disclosure, as well as by other hardware, software, firmware, or combinations thereof. The two-plane balancing method according to flowchart 100 includes the steps of:

in step 110, the motor 50 rotates the rotating base 30 at a constant rotational speed.

In step 112, motor signals, sampling times, rotational base 30 angular positions, etc. are measured.

In this step 112, the acquisition of the relevant data may preferably be done by means of the motor controller 51 and/or a control device of the gantry mechanism.

In step 114, the rotational speed and rotational speed accuracy of the rotating base 30 are calculated. In this step 114, the calculation of the rotational speed and rotational speed accuracy of the rotating base 30 may be accomplished by the control means of the gantry mechanism.

In step 116, it is determined whether the rotational speed accuracy is equal to or less than a set value. If the determination is negative, the flow goes to step 118, and if the determination is positive, the flow goes to step 119.

In step 118, the motor controller 51 controls the rotation base 30 to rotate to improve the rotational speed accuracy. After step 118 is completed, the process returns to step 114 to again calculate the rotational speed and rotational speed accuracy of the rotating base 30.

In step 119, the rotating base 30 is controlled to rotate and collect motor signals, sensor signals, sampling time, rotationThe angular position of the base 30, etc. are used as reference test data for the test. In this step 119, reference test data are acquired with the rotational speed of the rotating base 30 substantially constant, the rotational speed of the rotating base 30 preferably being close to or equal to the highest rated rotational speed of the rotating base 30, and based on these acquired signals, the signal of the sensor and the current or power of the motor are processed by the control device to extract the signal occurring once per revolution of the rotating base 30, a vector signal X can be obtained ₀ And Z ₀ 。

In step 120, the amount of unbalance of the stage mechanism 20 is calculated.

In step 121, it is determined whether the unbalance amount is equal to or smaller than a set value. If the determination is negative, indicating that the amount of imbalance of the gantry mechanism 20 exceeds the predetermined range, the process moves to step 122; if the determination is yes, it is indicated that the unbalance amount of the stage mechanism 20 is within the predetermined range, and the process ends.

In step 122, test block A is added. In this step 122, the weight and position of test block A are preset. The test block a may be mounted at an angle of about 180 degrees to the second weight mechanism 32.

In step 124, the rotating base 30 is controlled to rotate and collect motor signals, sensor signals, sampling times, angular position of the rotating base 30, etc. as test a data. In this step 124, acquisition of test a data is performed with the rotation speed of the rotating base 30 substantially constant, the rotation speed of the rotating base 30 preferably being close to or equal to the highest rated rotation speed of the rotating base 30, and based on these acquired signals, the signal of the sensor and the current or power of the motor are processed by the control device, the signal occurring once per revolution of the rotating base 30 is extracted, and the vector signal X can be obtained _a And Z _a 。

In step 126, test block A is removed.

In step 128, test block B is added. In this step 128, the weight and position of the test block B are preset. For example, the test block B is set at a position rotated clockwise by about 30 degrees with respect to the 0 degree position.

In step 130, the rotating base 30 is controlled to rotate and collect motor signals, sensor signals, sampling time, angular position of the rotating base 30, etc. as test B data. Based on the acquired data, the control device processes the current or power of the motor and the signals of the sensor to extract the signal which appears once every revolution of the rotating base 30, and the vector signal X can be obtained _b And Z _b 。

In step 132, test block B is removed.

In step 134, a sensitivity matrix [ c ] is calculated]. In this step 134, the calculation can be performed using the above formulas (1), (2), (3), (4), (5), based on the vector signal X obtained in the above steps 119, 124, 130 ₀ 、Z ₀ 、X _a 、Z _a 、X _b 、Z _b From these formulas, P can be obtained by solving _a And P _b 。

In step 136, the initial configuration of the two weight mechanisms on the gantry mechanism is entered.

In step 138, a new configuration of two weight mechanisms on the gantry mechanism 20 is calculated using the resolver. In this step 138, the new configuration of the weight mechanism can be deduced by formulas (6), (7), (8), (9) and (10).

In step 140, the two weight mechanisms on the gantry mechanism are reconfigured in a new configuration to correct the gantry mechanism imbalance.

In step 142, the rotating base 30 is controlled to rotate and collect motor signals, sensor signals, sampling time, angular position of the rotating base 30, and the like, based on the two weight mechanisms rearranged on the gantry mechanism. In this step 142, the rotating base 30 is preferably also rotated at a substantially constant rotational speed that is near or equal to the highest rated rotational speed.

In step 144, the current or power of the motor and the sensor signals are processed by the control device to extract the fluctuation signal that appears once per revolution of the rotating base 30, and calculate the unbalance amount of the gantry mechanism again.

In step 146, it is determined whether the unbalance amount is equal to or smaller than the set value. If the judgment result is noIndicating that the imbalance correction is not expected, the process loops to step 138 with the previously stored sensitivity matrix [ c ]]Can be directly called; if the result of the judgment is yes, the unbalance correction reaches the expected value, and the process is ended. In this step 146, it is determined whether the unbalance amount is smaller than the set value Δs based on the formulas (9) and (10) _t And DeltaD _t 。

In another aspect according to the present disclosure, static balance correction may be performed on the CT system using the current or power signal of the motor 50. This is particularly advantageous for low speed CT imaging systems. For low rotational speed CT imaging systems, the dynamic imbalance effect is small and correction may not be performed, but only the balance correction of the static balance. In this case, the balance correction can be accomplished by using only the signal sent from the motor 50 without providing or using a dedicated sensor 60 for measuring the Z-axis directional unbalance. Similar to the two-plane balance correction, the process of the static balance correction may also include a data acquisition step in which only the current or power signals of the motor are acquired, and a state data acquisition step in which the current or power signals from the motor 50 are subsequently processed to obtain state data related to the static balance state of the CT gantry mechanism. The obtained state data can correspond to the configuration of the weight mechanism on the swivel base 30, and the weight mechanism can be adjusted based on the balance calculation result of the state data. The static balancing method for performing the balance correction of the stage mechanism 20 using the motor 50 signal is as follows.

First, the motor 50 rotates the rotating base 30, and the motor controller 51 of the motor 50 advantageously makes the rotation speed of the rotating base 30 reach a constant value as much as possible, and the control device of the gantry mechanism 20 collects signals such as current or power, sampling time, and angular position of the rotating base 30 of the motor 50.

If the signal acquisition is performed at equal intervals, fourier transform or least squares may be used to process and extract the signal that occurs once per revolution of the rotating base 30, or if the sampling is not performed at equal intervals, least squares may be used for processing. Where the control means signals the current or power of the motor 50In principle, a fluctuation signal occurring once per rotation of the rotation base 30 is extracted, and expressed as a vector signal V including the amplitude and the phase angle ₁ 。

Then, the obtained vector signal V is used ₁ The output torque M of the motor 50 is calculated by the following formula ₁ ：

M ₁ ＝K _t *V ₁ (11)

Wherein K is _t Is the conversion factor of the motor 50 current and output torque, which is known.

At this time, the static unbalance torque S caused by the rotating portion of the stage mechanism 20 ₁ Equal to the output torque M of the motor 50 ₁ The method comprises the following steps:

S ₁ ＝K _t *V ₁ (12)

it will be appreciated that when an equal and opposite torque Q is applied ₁ Thereafter, a corresponding increase in the counter-acting static imbalance force F is provided on the rotating portion of the gantry mechanism 20 _x-add And F _y-add . If a new static unbalance force F is generated by a new arrangement of the first and second weight mechanisms 31, 32 _x-new1 And F _y-new1 And F _x-new1 And F _y-new1 Initial static unbalance force F generated with initial arrangement of the first and second weight mechanisms 31 and 32 _x-initial And F _y-initial The following equation is satisfied and the gantry mechanism is able to achieve a static balance.

Accordingly, the number of weights required on the first and second weight mechanisms 31, 32 and the corresponding Z-direction installation positions can be determined by means of the following equations (14) and (15) using a resolving program and algorithm.

In the above formula, ΔF _x And DeltaF _y Respectively represent the static unbalance amount in X and Y directions, and delta S _t Representing the total static imbalance tolerance allowed by the CT system. After the configurations of the first weight mechanism 31 and the second weight mechanism 32 of the stage mechanism are reset according to the obtained calculation result, correction of the static balance of the stage mechanism can be performed.

Fig. 8A and 8B illustrate a flow chart 200 of a static balancing method according to a preferred embodiment of the present disclosure. The logic of the related flow chart 200 may be implemented by a control device of the CT gantry mechanism 20 according to the present disclosure, as well as by other hardware, software, firmware, or combinations thereof. The static balancing method according to the flowchart 200 includes the steps of:

In step 210, the spin base 30 is rotated at a constant rotational speed. In this step 210, the rotation of the rotating base 30 may be controlled by the motor controller 51, preferably such that the rotating base 30 rotates at a constant rotational speed that is close to or equal to the highest rated rotational speed of the rotating base 30.

In step 212, motor signals, sampling times, rotational base 30 angular position, etc. are measured. In this step 212, the acquisition of the relevant data may preferably be accomplished by means of the motor controller 51 and the control means of the gantry mechanism.

In step 214, the rotational speed and rotational speed accuracy of the rotating base 30 are calculated. In step 214, the calculation of the rotational speed and rotational speed accuracy of the rotating base 30 may be accomplished by the control means of the gantry mechanism.

In step 216, it is determined whether the rotational speed accuracy satisfies a preset value. If the determination is negative, the process passes to step 218; if the determination is yes, the process goes to step 220.

In step 218, the motor controller 51 controls the rotation of the rotation base 30 to increase the rotational speed accuracy. Subsequently, the process returns to step 214 to calculate the rotational speed and rotational speed accuracy of the rotating base 30 again.

In the step220, the magnitude of the imbalance indicative of the gantry mechanism, and the phase angle are calculated. In this step 220, the signal of the current or power of the motor is processed by the control means by means of the current and power signals of the motor, the signal occurring once per revolution of the rotating base 30 is extracted and expressed as a vector signal V comprising the amplitude and phase angle ₁ 。

In step 222, it is determined whether the magnitude of the imbalance satisfies a predetermined value. If the determination is negative, indicating that the amount of imbalance of the gantry mechanism 20 exceeds the predetermined range, the process proceeds to step 224; if the determination is yes, it is indicated that the unbalance amount of the stage mechanism 20 is within the predetermined range, and the process ends.

In step 224, the initial configuration of two weight mechanisms on the gantry mechanism is entered.

In step 226, a new configuration of two weight mechanisms on the gantry mechanism is calculated using the solver. In step 226, a new configuration of the two weight mechanisms can be calculated by formulas (11), (12), (13), (14) and (15).

In step 228, the two weight mechanisms on the gantry mechanism are adjusted to a new configuration to correct the gantry mechanism static imbalance. Subsequently, the process loops to step 210 to re-determine whether the rotational speed and rotational speed accuracy of the rotating base, and the static unbalance amount meet the preset requirements, until the static unbalance amount is within the tolerance range, and the static balance correction process is terminated.

In performing the dynamic and static balance correction, the rotation speed of the rotation base 30 may be set as high as possible. When there is an imbalance in the rotating portion of the gantry mechanism 20, the forces and moments generated by the imbalance increase as the rotational speed of the rotating base 30 increases. Theoretically, the torque produced by the imbalance is proportional to the square of the speed, and therefore, as the rotational speed of the rotating base 30 increases, the amplitude of the signal produced by the motor 50 and sensor 60 in response to the imbalance increases accordingly. Therefore, in performing dynamic and static balance correction, the constant rotation speed of the rotating base 30 may be set to be close to or equal to the rated maximum rotation speed of the rotating base 30.

For CT imaging systems with high rotational speeds, multiple balance correction operations may be performed. In a preferred embodiment, the rotating base 30 can be rotated at a lower rotational speed during the first balance correction; at the subsequent balancing correction, the rotating base 30 is rotated at a higher or near nominal maximum rotational speed. The balance correction method has the advantage that the balance correction accuracy can be improved as much as possible under the premise of ensuring the safety of the system. Here, the number of balance corrections and the balance correction rotational speed are illustrative, not restrictive.

The uniform rotation of the rotating base 30 is advantageous for measurement accuracy. That is, the smaller the fluctuation in the rotational speed of the rotating base 30, the more accurately the resultant vector signal reflects the imbalance of the rotating portion of the gantry mechanism 20.

It should be appreciated that in other alternative embodiments, if the current or power of the motor 50 is signal-collected with reference to a defined sampling angle of rotation of the rotating base 30, the rotating base 30 is not required to achieve or approach a constant rotational speed rotation, i.e., the collection of motor and sensor signals may also be performed during an acceleration or deceleration rotation of the rotating base 30.

In the system and method for detecting or balancing the state of the gantry mechanism according to the present disclosure, the original motor 50 of the gantry mechanism is used as a sensor for measuring the rotational resistance moment of the gantry mechanism, and a special measuring sensor is not required. The signals of the motor 50 can be used for detecting and correcting dynamic balance and static balance, so that the system cost is saved. In addition, by reducing the fluctuation of the rotation speed of the motor 50, the accuracy of the signal expression unbalance degree of the motor 50 can be improved, thereby realizing the balance correction with high accuracy on the premise of low cost.

For low-speed systems, only a motor is needed to achieve balance correction, and the whole CT imaging system is further simplified.

According to another preferred embodiment, as illustrated in fig. 9, the present disclosure also provides a status detection apparatus for a medical imaging system. The apparatus includes a data acquisition module 410 and a status data acquisition module 420, wherein the data acquisition module 410 acquires a current or power signal of the motor to obtain a first signal, and the status data acquisition module 420 acquires status data based on the first signal and related to a specific status of the medical imaging system. More specifically, the data acquisition module 410 is configured to sample a current or power signal of the motor 50 as the motor 50 drives the rotating base 30 to rotate relative to the stationary frame 40, obtaining a first signal. The detection and status data acquisition module 420 is configured to extract from the first signal a signal corresponding to a particular status of the gantry mechanism, such as a signal due to an imbalance of the gantry mechanism, the signal being a signal that occurs once per revolution of the rotating base 30; or a signal due to a malfunction of the gantry mechanism, which is a signal that the rotation base 30 appears twice or three times per rotation. The state data acquisition module 420 may be further configured to calculate magnitude and phase angle associated with a particular state of the gantry mechanism 20, such as calculating magnitude and phase angle associated with an imbalance state of the gantry mechanism 20, based on the extracted signals. In the application of balance correction, the magnitude and the associated phase angle correspond to the configuration of the counterweight mechanism on the rotating base, and balance correction can be achieved by balance calculation based on the magnitude and the phase angle.

In performing the two-plane balancing method to correct the dynamic balance of the gantry mechanism 20, the data acquisition module 410 may be further configured to sample the output signal of the sensor 60 disposed on the gantry mechanism 20 to obtain a second signal. And the status data acquisition module 420 acquires status data based on the second signal and related to a particular status of the medical imaging system. And the status data acquisition module 420 is configured to extract a signal corresponding to a particular status of the gantry mechanism, such as a signal due to an imbalance of the gantry mechanism, from the second signal, the signal being a signal that occurs once per revolution of the rotating base 30; or a signal due to a malfunction of the gantry mechanism, which is a signal that the rotation base 30 appears twice or three times per rotation. Meanwhile, the state data acquisition module 420 is configured to obtain state data related to the dynamic balance state based on the first signal and the second signal, wherein the second signal is also a fluctuation signal occurring once every revolution of the rotating base. The calculated adjustment based on the state data may balance correct the dynamic balance of the gantry mechanism 20.

In some embodiments, the status data acquisition module 420 may include a signal extraction module and a calculation module. The signal extraction module 420 is configured to extract a signal from the first signal, for example, due to a gantry mechanism imbalance. The calculation module may be configured to calculate magnitude and phase angle associated with a particular state of the gantry mechanism, such as calculating magnitude and phase angle of imbalance of the rotating portion of the gantry mechanism 20, based on the extracted signals. The signal extraction module may include a processing module configured to fourier transform or least squares process the acquired signals to obtain signals that occur once per revolution of the rotating base 30. If the signal is obtained by sampling at equal time intervals, the processing module performs Fourier transform processing on the acquired signal. If the signal is not obtained by sampling at equal time intervals, the processing module performs least square processing on the acquired signal.

Furthermore, in some embodiments, the status detection apparatus 400 may further include or integrate a motor control module 450, the motor control module 450 being configured to control the motor to rotate the rotating base 30 of the gantry mechanism at an acceleration, deceleration, or constant rotational speed, wherein the constant rotational speed is near or equal to a nominal maximum rotational speed of the rotating base 30.

The techniques described herein may be implemented in hardware, software, firmware, or any combination thereof, unless specifically described as being implemented in a specific manner. Any features described as modules or components may also be implemented together in an integrated logic device or separately as discrete but interoperable logic devices. If implemented in software, the techniques may be realized at least in part by a non-transitory computer-readable storage medium including instructions that, when executed, perform one or more of the methods described above. The non-transitory processor-readable data storage medium may form part of a computer program product that may include packaging material. The program code may be implemented in a high level procedural or object oriented programming language to communicate with a processing system. Program code can also be implemented in assembly or machine language, if desired. Indeed, the mechanisms described herein are not limited in scope to any particular programming language. In any case, the language may be a compiled or interpreted language.

One or more aspects of at least some embodiments may be implemented by representative instructions stored on a machine-readable medium which represent various logic in a processor, which when read by a machine, cause the machine to fabricate logic to perform the techniques described herein. Such machine-readable storage media may include, but are not limited to, non-transitory tangible arrangements of articles manufactured or formed by a machine or device, including storage media such as: a hard disk; any other type of disk including floppy disks, optical disks, compact disk read-only memories (CD-ROMs), compact disk rewriteable (CD-RWs), and magneto-optical disks; semiconductor devices such as read-only memory (ROM), random Access Memory (RAM) such as Dynamic Random Access Memory (DRAM) and Static Random Access Memory (SRAM), erasable programmable read-only memory (EPROM), flash memory, electrically erasable programmable read-only memory (EEPROM); phase Change Memory (PCM); magnetic cards or optical cards; or any other type of medium suitable for storing electronic instructions.

While the present disclosure has been described in terms of preferred embodiments, it is not intended to limit the disclosure, and variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the disclosure. Therefore, any modification, equivalent variation and modification of the above embodiments according to the technical substance of the present disclosure fall within the protection scope defined by the claims of the present disclosure.

Claims

1. A state detection method of a medical imaging system including a stationary frame and a rotating portion including a rotating base driven by a motor, the method comprising:

a data acquisition step of acquiring a current or power signal of the motor under the condition that the motor is controlled to rotate the rotating base at a constant rotation speed to obtain a first signal; and

a state data acquisition step of acquiring state data which is based on the first signal and which is related to a specific state of the medical imaging system, wherein the specific state includes an unbalanced state or a failure state of the rotating portion, the state data being obtained by processing the first signal using one of fourier transform and least square method when the first signal is obtained by sampling at equal time intervals, and the state data being obtained by processing the first signal using least square method when the first signal is obtained by sampling at different time intervals.

2. The method of claim 1, wherein the first signal comprises a current or power ripple signal occurring once per revolution of the rotating base.

3. The method of claim 2, wherein the status data includes a magnitude and a phase angle of the first signal, the status data corresponding to a configuration of a weight mechanism on the rotating base.

4. The method of claim 2, wherein the data acquisition step further comprises: collecting a second signal output by a sensor arranged on the fixed frame, and

the status data acquisition step further comprises acquiring supplemental status data based on the second signal and related to a particular status of the medical imaging system, wherein a fluctuating signal occurs once per revolution of the rotating base, corresponding to a configuration of a weight mechanism on the rotating base.

5. The method of claim 4, wherein the status data acquisition step comprises: extracting a fluctuation signal which appears once every turn of the rotating base from the first signal or the second signal; and

based on the extracted fluctuation signal, an amplitude value associated with the specific state of the medical imaging system is calculated.

6. The method of any of claims 1-5, wherein the constant rotational speed is also near or equal to a rated maximum rotational speed of the rotating base.

7. A state detection device of a medical imaging system including a stationary frame and a rotating portion including a rotating base driven by a motor, the state detection device comprising:

a motor control module configured to control the motor to rotate the rotating base at a constant rotation speed;

a data acquisition module configured to acquire a current or power signal of the motor under a condition that the motor is controlled to rotate the rotating base at a constant rotation speed to obtain a first signal; and

a state data acquisition module configured to acquire state data based on the first signal and related to a specific state of the medical imaging system, wherein the specific state includes an unbalanced state or a faulty state of the rotating portion, the state data being obtained by processing the first signal using one of fourier transform and least square method when the first signal is obtained by sampling at equal time intervals, and the state data being obtained by processing the first signal using least square method when the first signal is obtained by sampling at different time intervals.

8. The condition sensing device of claim 7, wherein the first signal comprises a current or power ripple signal occurring once per revolution of the rotating base.

9. The condition detection apparatus of claim 8, wherein the condition data includes a magnitude and a phase angle of the first signal, the condition data corresponding to a configuration of a weight mechanism on the rotating base.

10. The state detecting apparatus of claim 8, wherein,

the data acquisition module is further configured to acquire a second signal output by a sensor disposed on the stationary frame, and

the status data acquisition module is further configured to acquire supplemental status data based on the second signal and related to a particular status of the medical imaging system, wherein a fluctuation signal occurring once per revolution of the rotating base corresponds to a configuration of a weight mechanism on the rotating base.

11. The state detection device of claim 10, wherein the state data acquisition module is further configured to:

extracting a fluctuation signal which appears once every turn of the rotating base from the first signal or the second signal; and

12. The status detection apparatus according to any one of claims 7 to 11, wherein,

the constant rotational speed is near or equal to a rated maximum rotational speed of the rotating base.

13. The condition sensing device of claim 10, wherein the first signal comprises a current or power ripple signal that occurs multiple times per revolution of the rotating base, and the second signal comprises a ripple signal that occurs multiple times per revolution of the rotating base.

14. A CT imaging system, the CT imaging system comprising:

a fixed frame and a rotating portion including a rotating base driven by a motor;

at least one weight mechanism comprising at least one weight that is adjustable;

a state detection device comprising a data acquisition module configured to acquire a current or power signal of the motor under control of the motor to rotate the rotating base at a constant rotational speed to obtain a first signal, and a state data acquisition module configured to acquire state data based on the first signal and related to a specific state of the CT imaging system, wherein the specific state comprises an unbalanced state or a faulty state of the rotating part, i.e. when the first signal is obtained by an equal time interval sampling, the state data is obtained by processing the first signal using one of fourier transform and least square method, and when the first signal is obtained by an unequal time interval sampling, the state data is obtained by processing the first signal using least square method, the state data being indicative of an adjustment of the at least one balancing weight.

15. The CT imaging system of claim 14, further comprising a sensor disposed on said stationary frame,

wherein the sensor is disposed at an upper portion or a middle portion of the fixed frame when the sensor is selected from the group consisting of an acceleration sensor, a speed sensor, and a displacement sensor, and is disposed at a lower portion of the fixed frame when the sensor is selected from the group consisting of a strain sensor and a piezoelectric sensor.

16. The CT imaging system of claim 15, wherein the data acquisition module is further configured to acquire signals of the sensor to obtain a second signal, the status data acquisition module is further configured to acquire supplemental status data based on the second signal and related to a particular status of the CT imaging system, wherein a fluctuation signal occurring once per revolution of the rotating base corresponds to a configuration of a weight mechanism on the rotating base.

17. The CT imaging system of claim 14, further comprising a first test block and a second test block, the first test block and the second test block having a predetermined weight, respectively, an installation location, the first signal comprising a surge signal occurring once per revolution of the rotating base without the first test block and the second test block installed, respectively.

18. The CT imaging system of claim 14, wherein the first signal comprises a current or power fluctuation signal that occurs multiple times per revolution of the rotating base.

19. The CT imaging system of claim 14, wherein the rotating portion further comprises an X-ray tube mounted on the rotating base, the X-ray tube disposed at a 0 degree position about a central axis of the rotating portion, and

the at least one weight mechanism comprises a first weight mechanism and a second weight mechanism, the rotation angle between the first weight mechanism and the second weight mechanism is different by 80-120 degrees around the central axis, and the second weight mechanism is arranged at a position rotated 180 degrees relative to the 0-degree position.

20. The CT imaging system of claim 16, wherein,

the at least one weight mechanism includes a first weight mechanism and a second weight mechanism; and is also provided with

The status data acquisition module is further configured to:

processing the second signal using one of a fourier transform and a least squares method when the second signal is obtained by sampling at equal time intervals;

Processing the second signal using a least squares method when the second signal is obtained by sampling at different time intervals;

extracting a current or power fluctuation signal occurring once per revolution of the rotating base from the processed first signal and the second signal;

calculating an amplitude and a phase angle associated with the particular state of the CT imaging system based on the extracted fluctuation signal; and

when the calculated amplitude does not satisfy a preset value, new configurations of a first weight mechanism and a second weight mechanism provided at different positions on the rotating portion are calculated according to the amplitude and the phase angle.