CT gantry, signal transmission method of CT gantry, CT device, and storage medium

Abstract

The application provides a CT stand, a signal transmission method of the CT stand, a CT device and a storage medium. The application can realize simple structure, low cost, low power consumption, stable data transmission and fast data transmission speed. The CT stand comprises a rotating part, an X-ray tube ball and a detector; a fixed part supporting the rotating part; a slip ring for power transmission and transmission of communication signals based on power line carrier communication between the rotating part and the fixed part; a parameter determination part for determining actual communication channel estimation parameters corresponding to the communication signals based on a channel estimation data model according to the rotating speed and rotating angle of the rotating part of the CT stand at the time when the communication signals are transmitted; and a signal transmission control part for controlling the transmission of the communication signals by modulating / demodulating the communication signals using the actual communication channel estimation parameters.

Description

Technical Field

[0001] This disclosure relates to a CT gantry using slip rings as a PLC communication medium, a signal transmission method for the CT gantry, a CT device, and a storage medium. Background Technology

[0002] Currently, many medical devices employ structural systems that require simultaneous rotation and the transmission of power and signals. Slip rings are indispensable in such systems. Slip rings are components used in electromechanical systems that demand continuous rotation while transmitting power and signals from a fixed position to a rotating position. In CT systems, the need for reliable transmission of high-power current, communication signals, and high-speed digital imaging signals places high demands on the technology and sophistication of slip rings. Typically, slip rings in medical systems have specific requirements regarding current level, rotational speed, and space requirements.

[0003] CT systems can utilize slip rings as a PLC communication medium to achieve communication between fixed and rotating parts. PLC communication is Power Line Communication (PLC). PLC communication refers to the technology of transmitting analog or digital signals at high speed using power lines and carrier waves.

[0004] PLCs operate at carrier frequencies between 2MHz and 80MHz, primarily utilizing OFDM (Orthogonal Frequency Division Multiplexing) technology for communication. The basic idea of ​​OFDM is to decompose the data stream into several independent low-speed bit streams; in the frequency domain, this means dividing it into multiple subcarriers, which are then transmitted in parallel. In OFDM, each subcarrier corresponds to a specific frequency, meaning the quality of carrier transmission directly impacts the communication quality.

[0005] In a CT system, when the gantry rotates at high speed, the slip ring becomes a rapidly time-varying channel. The channel parameters are different at every moment, and the channel at any given moment is affected by noise, multipath effects, and impedance mismatch. Furthermore, each moment corresponds to a real-time rotation angle θ, determined by the current rotation speed of the CT gantry. Multipath effects arise because the slip ring size is comparable to the carrier wavelength; impedance mismatch occurs due to reflections at the slip ring's connection points; and the magnitude of noise depends on the environmental conditions of the CT system. Thus, this time-varying channel with numerous interferences can significantly reduce transmission speed.

[0006] While real-time adaptive channel estimation algorithms exist for time-varying channels, they are not suitable for the characteristics of time-varying channels in CT systems. According to real-time adaptive channel estimation algorithms, the transmitter uses the channel estimation parameters at signal transmission time t1 for modulation. However, due to the high-speed rotation of the transmission platform, the channel actually traversed at transmission time t2 has changed relative to the channel at t1. This high-speed rotation leads to significant differences in the channel estimation parameters between t1 and t2. Consequently, the accuracy of signal demodulation by the receiver is greatly reduced. Because the channel estimation based on real-time adaptive channel estimation algorithms cannot keep up with the rate at which the channel changes over time, transmission instability and a severe decrease in transmission speed occur. Summary of the Invention

[0007] The purpose of this invention is to provide a CT gantry with simple structure, low cost, low power consumption, stable data transmission, and fast data transmission speed, as well as a signal transmission method for the CT gantry, a CT device, and a storage medium.

[0008] Means for solving technical problems

[0009] A CT gantry according to an embodiment of the present invention includes: a rotating part that carries an X-ray tube and a detector and rotates; a fixing part that supports the rotating part; a slip ring that transmits power and a communication signal based on power line carrier communication between the rotating part and the fixing part; a parameter determination part that determines actual communication channel estimation parameters corresponding to the communication signal based on a channel estimation data model, according to the rotation speed and rotation angle of the rotating part of the CT gantry at the time the communication signal is transmitted; and a signal transmission control part that controls the transmission of the communication signal to modulate / demodulate the communication signal using the actual communication channel estimation parameters.

[0010] In addition, the CT gantry of the present invention also includes a model acquisition unit, which acquires the channel estimation data model by a non-blind channel estimation method.

[0011] Furthermore, in the CT gantry of the embodiments of the present invention, the model acquisition unit inserts known pilot symbols and / or sequences into the communication signal at the signal transmitting end, extracts the pilot symbols and / or sequences at the receiving end, performs channel estimation calculations to acquire channel parameters, and acquires the channel estimation data model based on the acquired channel parameters.

[0012] In addition, in the CT gantry of the embodiments of the present invention, the model acquisition unit transmits known pilot symbols and / or sequences at the signal transmitting end, extracts the pilot symbols and / or sequences at the receiving end, performs channel estimation calculations to acquire channel parameters, and acquires the channel estimation data model based on the acquired channel parameters.

[0013] Furthermore, in the CT gantry of the embodiments of the present invention, when the CT gantry has multiple rotation speeds, the model acquisition unit performs channel parameter acquisition at multiple predetermined positions at intervals of predetermined rotation angles for each of the multiple rotation speeds.

[0014] Furthermore, in the CT gantry of the embodiments of the present invention, the model acquisition unit performs channel parameter acquisition more than a predetermined number of times at each predetermined position for each of the multiple rotation speeds.

[0015] Furthermore, in the CT gantry of the embodiments of the present invention, the channel parameter acquisition includes channel parameter acquisition from the fixed part to the rotating part, and channel parameter acquisition from the rotating part to the fixed part.

[0016] In addition, in the CT gantry of the embodiments of the present invention, the channel estimation data model is constructed before the CT gantry leaves the factory and is updated periodically after leaving the factory.

[0017] Furthermore, in the CT gantry of the embodiment of the present invention, when transmitting communication signals from the fixed part to the rotating part, the rotation angle is obtained by a rotary encoder provided on the fixed part.

[0018] Furthermore, the CT gantry according to the embodiments of the present invention also includes a measuring unit, through which the rotation angle is obtained when transmitting communication signals from the rotating part to the fixed part.

[0019] In addition, in the CT gantry of the embodiments of the present invention, the measuring unit is any one of a combination of a gyroscope and an accelerometer, a dual-axis tilt sensor, or an encoder.

[0020] Furthermore, the CT apparatus according to the embodiments of the present invention includes the CT gantry described in any of the above claims.

[0021] Furthermore, the signal transmission method for a CT gantry according to an embodiment of the present invention includes: a rotating part that carries an X-ray tube and a detector for rotation; a fixed part that supports the rotating part; and a slip ring for power transmission and transmission of communication signals based on power line carrier communication between the rotating part and the fixed part. The signal transmission method for the CT gantry includes: a parameter determination step, which determines actual communication channel estimation parameters corresponding to the communication signal based on a channel estimation data model according to the rotation speed and rotation angle of the rotating part of the CT gantry at the time the communication signal is transmitted; and a signal transmission control step, which performs control to modulate / demodulate the communication signal using the actual communication channel estimation parameters, thereby transmitting the communication signal.

[0022] Furthermore, the storage medium of the embodiments of the present invention stores, in a computer-readable manner, a program that causes the CT gantry described in any of the above claims to perform the following processes: parameter determination processing, which determines, based on a channel estimation data model, actual communication channel estimation parameters corresponding to the communication signal according to the rotation speed and rotation angle of the CT gantry rotating part at the time the communication signal is transmitted; and signal transmission control processing, which performs control to modulate / demodulate the communication signal using the actual communication channel estimation parameters, thereby transmitting the communication signal.

[0023] The effects of the invention

[0024] The CT gantry, CT gantry signal transmission method, CT device, and storage medium described in the above embodiments of the present invention can achieve simple structure, low cost, low power consumption, stable data transmission, and fast data transmission speed. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the CT stand according to the first embodiment of the present invention.

[0026] Figure 2A This is a schematic diagram illustrating the data transmission of a CT gantry in accordance with embodiments of the present invention.

[0027] Figure 2B This is a schematic diagram illustrating the data transmission process of the CT gantry in the comparative example.

[0028] Figure 3 This is a schematic diagram of the structure of the CT stand according to the second embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram illustrating one method of channel parameter estimation according to the present invention.

[0030] Figure 5This is a schematic diagram illustrating another method of channel parameter estimation for the present invention.

[0031] Figure 6 This is a schematic diagram illustrating the process of obtaining the channel estimation data model.

[0032] Figure 7 This is a schematic diagram illustrating Embodiment 1 for obtaining the rotation angle.

[0033] Figure 8 This is a schematic diagram illustrating Embodiment 2 for obtaining the rotation angle.

[0034] Figure 9 This is a schematic diagram illustrating Example 3 for obtaining the rotation angle. Detailed Implementation

[0035] Hereinafter, with reference to the accompanying drawings, embodiments of the CT gantry, CT gantry signal transmission method, CT device, and storage medium of the present invention will be described.

[0036] Furthermore, in this specification and accompanying drawings, only the components related to the technical concept of the present invention are described and shown, while other components are omitted.

[0037] In addition, in this specification and the accompanying drawings, components with the same or similar functions are labeled with the same reference numerals, and repeated descriptions are omitted where appropriate.

[0038] (First Implementation)

[0039] Figure 1 This is a schematic diagram of the structure of the CT stand according to the first embodiment of the present invention.

[0040] like Figure 1 As shown, the CT gantry 1 of the first embodiment of the present invention includes a rotating part 101, a fixing part 102, a slip ring 103, a communication unit PLC1 disposed in the rotating part 101, and a communication unit PLC2 disposed in the fixing part 102. The communication units PLC1 and PLC2 further include a parameter determination unit 104 and a signal transmission control unit 110, respectively.

[0041] Furthermore, in this specification, the parameter determination unit and signal transmission control unit of each of the communication units PLC1 and PLC2 are not distinguished, and are referred to by the same reference numerals. It should be noted that this specification describes the case where the signal is transmitted from the rotating part 101 to the stationary part 102 in detail; therefore, the parameter determination unit 104 and signal transmission control unit 110 described below refer to the parameter determination unit 104 and signal transmission control unit 110 of the communication unit PLC1 of the rotating part 101. On the other hand, if the signal is transmitted from the stationary part 102 to the rotating part 101, the parameter determination unit 104 and signal transmission control unit 110 of the communication unit PLC2 of the stationary part 102 are used instead of the parameter determination unit 104 and signal transmission control unit 110 described below.

[0042] The rotating part 101 is used to mount an X-ray tube and a detector for receiving X-rays, and rotates accordingly. Under the control of a control unit (not shown), the rotating part 101 rotates periodically in several fixed modes. In each mode, the rotational speed of the rotating part 101 is constant.

[0043] The fixing part 102 is used to support the rotating part 101.

[0044] The slip ring 103 is made of a conductive material and can be used for power transmission between the rotating part 101 and the fixed part 102, as well as for transmitting communication signals via a power line carrier communication (PLC) channel. The communication signal transmission in the CT gantry 1 is full-duplex communication, including communication when the communication signal is transmitted from the rotating part 101 to the fixed part 102 and when the communication signal is transmitted from the fixed part 102 to the rotating part 101. In the CT gantry 1, the positions of the signal transmitting end and the signal receiving end are fixed relative to the slip ring 103. Therefore, as the rotating part 101 rotates, the parameters of the channel based on the slip ring 103 are different at each moment, making the channel based on the slip ring 103 a time-varying channel. Furthermore, in both the communication signal transmission from the rotating part 101 to the fixed part 102 and the communication signal transmission from the fixed part 102 to the rotating part 101, generally, after the communication signal is transmitted, it is modulated by a modulator and then transmitted through the channel. After passing through the channel, it is demodulated by a demodulator and then received by the receiving end. Modulation and demodulation both require time. Therefore, in communication based on a time-varying channel such as slip ring 103, the time of transmitting the signal is different from the time of transmitting the signal.

[0045] The parameter determination unit 104 is composed of processors such as CPU (Central Processing Unit), GPU (Graphics Processing Unit), and MCU (Micro Control Unit). Based on the rotation speed and rotation angle of the rotating part 101 of the CT stand 1 at the moment the communication signal is transmitted, it determines the actual communication channel estimation parameters corresponding to the communication signal based on the channel estimation data model.

[0046] Here, the channel estimation data model includes a model representing the communication process when the communication signal is transmitted from the rotating part 101 to the fixed part 102, and a communication model representing the transmission of the communication signal from the fixed part 102 to the rotating part 101. This channel estimation data model is used in PLC communication on the CT stand 1 to match and obtain channel estimation parameters for modulation and demodulation.

[0047] The channel estimation data model can be pre-built and stored, either in the memory of the CT gantry 1 (not shown) or in a device other than the CT gantry 1 that can communicate with it.

[0048] For example, in this invention, the channel estimation data model is constructed before the CT stand 1 leaves the factory and is updated periodically afterward. For instance, before the CT stand 1 leaves the factory, the channel estimation data model is stored in non-volatile memory (Flash, EEPROM, SD card, etc.) so that the CT stand can match the corresponding channel estimation parameters in advance when performing signal modulation and demodulation. Furthermore, after the CT stand 1 leaves the factory, changes in its operating environment and conditions lead to changes in the transmission channel. Therefore, it is necessary to periodically maintain and update the channel estimation data model to ensure the real-time performance of the channel estimation parameters used by the CT stand 1.

[0049] Furthermore, in this invention, all operations on the channel estimation data model, whether before or after leaving the factory, are encapsulated as channel model construction commands. That is, by simply sending the channel estimation data model construction command, the CT platform 1 will automatically perform the data model construction operation for the current channel to complete the initial construction and periodic updates of the channel model. The method for constructing and updating the channel estimation data model will be described later.

[0050] Furthermore, as described above, the rotation speed of the rotating part 101 of the CT gantry 1 is determined according to several fixing modes of the CT gantry 1. That is, the CT gantry 1 has several constant rotation speeds.

[0051] In addition, the rotation angle of the rotating part 101 of the CT gantry 1 can be measured in real time. The rotation angle refers to the angle through which the X-ray tube on the rotating part 101 rotates relative to the reference position, and can be used to indicate the rotation position of the rotating part 101.

[0052] The signal transmission control unit 110, for example, performs control to modulate / demodulate the communication signal using the actual communication channel estimation parameters determined by the parameter determination unit 104, and then transmits the communication signal.

[0053] Figure 2A This is a schematic diagram illustrating the data transmission of a CT gantry in accordance with embodiments of the present invention. Figure 2B This is a schematic diagram illustrating the data transmission process of the CT gantry in the comparative example. First, regarding... Figure 2A and Figure 2B The reference numerals in the accompanying drawings are explained below. t1 represents the time when the signal is transmitted, i.e., the time when the input signal is received; t2 represents the time when the transmitted signal is transmitted after modulation of the input signal; θ t1 D represents the rotation angle at time t1; t1 (n) represents the input signal at time t1; n is the number of sampling points; S represents the channel estimation parameters at time t1 under rotational speeds v and v1, respectively; t1 (n) represents the modulated signal output at time t1, which is the input signal of the channel; H(v,θ) t2 H(v1,θ2)(n) and H(v1,θ2)(n) are the actual channels at time t2 with rotational speeds v and v1, respectively; S t2 (n) is the output signal of the channel, and the demodulated input signal at time t3; These are the channel estimates at time t2 for rotational speeds v and v1, respectively; D t3 (n) is the demodulated output signal obtained at time t3.

[0054] in addition, Figure 2A and Figure 2B These are examples where, when the rotating part 101 transmits a signal to the fixed part 102, the signal is sent at time t1, modulated by PLC1, transmitted at time t2, demodulated by PLC2, and then received by the receiving end. Additionally... Figure 2A In this example, the rotating part 101 is assumed to rotate at a speed of v1. Figure 2B In this example, the rotating part 101 is assumed to rotate at a speed v. Furthermore, the speed v1 can be the same as or different from the speed v.

[0055] like Figure 2AAs shown, in the CT gantry of the embodiment of the present invention, when the rotating part 101 transmits signal data to the fixed part 102, signal D is sent at time t1. t1 (n).

[0056] Subsequently, the parameter determination unit 104, based on the current operating mode of the CT gantry, knows its rotational speed v1, rotational angle θ1 at signal transmission time t1, and rotational angle θ2 at signal transmission time t2. The rotational angle θ1 can be obtained through real-time measurement by a sensor, and the rotational angle θ2 is calculated using the following formula.

[0057] θ2=θ1+ω1τ

[0058] Where ω1 is the angular velocity corresponding to the current rotational speed v1, satisfying ω=2π / v; τ is the time required for modulation calculation, which is a constant, satisfying τ=t2-t1.

[0059] Subsequently, the parameter determination unit 104 matches the channel estimation parameters corresponding to the time when the rotation angle is θ2 based on the channel estimation data model.

[0060] Furthermore, under the control of the signal transmission control unit 110, in D t1 (n) is used directly when sent. The signal is modulated, and the same method is directly used at the receiving end. Demodulate the signal, and obtain the demodulated signal D at time t3. t3 (n).

[0061] Thus, in the CT gantry of the embodiment of the present invention, the actual communication channel estimation parameters corresponding to the signal are determined based on the channel estimation data model, according to the rotational speed v1 and rotational angle θ1 of the CT gantry rotating part at the time t1 when the signal is transmitted. Modulation is performed during signal transmission, and demodulation is performed during signal reception. This takes into account the time-varying channel characteristics of slip ring 103, reducing the channel error between the modulated and demodulated signals and the actual transmission time, thereby reducing the transmission signal D. t1 (n) and the demodulated signal D t3 (n) The error is very small, which improves transmission quality. Furthermore, the CT gantry of this embodiment does not perform channel estimation during signal transmission, but directly applies a pre-established channel estimation data model to determine the actual communication channel estimation parameters corresponding to the communication signal, thereby improving transmission stability and transmission speed. In addition, since the parameter determination unit 104 and the signal transmission control unit 110 are located on the rotating unit 101, which serves as the signal transmission side, the communication channel estimation parameters can be performed more closely to the actual signal transmission channel, reliably improving transmission quality, transmission stability, and transmission speed.

[0062] On the other hand, such as Figure 2B As shown, in the prior art CT gantry as a comparative example, when the rotating part 101 transmits signal data to the fixed part 102, signal D is sent at time t1. t1 (n).

[0063] Subsequently, PLC1 modulates the signal using the channel estimation parameters obtained at the signal transmission time t1 based on a real-time adaptive channel estimation algorithm, resulting in the modulated signal S. t1 (n).

[0064] After that, the S t1 (n) passes through channel H(v,θ) at time t2 t2 After transmission, signal S is obtained. t2 (n).

[0065] Then, the signal S t2 (n) At the receiving end, PLC2 uses the channel estimation parameters at signal transmission time t2. Demodulation is performed, and the demodulated signal D is obtained at time t3. t3 (n).

[0066] Thus, in the comparative example, for a time-varying channel, a real-time adaptive channel estimation algorithm is applied. When the transmitter modulates the signal, it uses the channel estimation parameters at the time of signal transmission t1 for modulation, and time t1 corresponds to a rotation angle θ. t1 However, due to the high-speed rotation of the platform, the channel through which the signal is transmitted has changed. That is, the channel corresponding to the transmission time t2 is the actual channel for signal transmission, and time t2 also corresponds to a rotation angle θ. t2 Furthermore, the rotation distance (also known as the rotation interval) from time t1 to time t2 is determined by the rotation speed v of the CT gantry in the current mode. When the gantry rotates at high speed, v is very large, which will lead to a significant difference in the channel corresponding to times t1 and t2. Therefore, the accuracy of the receiver's signal demodulation is greatly reduced. As a result, the channel estimation based on real-time adaptive channel estimation can never keep up with the speed at which the channel changes over time, leading to unstable transmission and a severe decrease in transmission speed.

[0067] Furthermore, the above explanation used the case where the signal is transmitted from the rotating part to the fixed part as an example. The same process applies and achieves the same technical effect when the signal is transmitted from the fixed part to the rotating part; the difference lies in the method of obtaining the rotation angle θ1. When the signal is transmitted from the rotating part 101 to the fixed part 102, it is obtained using the measuring unit described later; when the signal is transmitted from the fixed part 102 to the rotating part 101, it is obtained using the rotary encoder integrated into the fixed part 102 of the CT gantry.

[0068] (Second Implementation)

[0069] Figure 3 This is a schematic diagram of a portion of the structure of the CT stand 1A according to the second embodiment of the present invention.

[0070] like Figure 3 As shown, the CT gantry 1A of the second embodiment of the present invention includes a rotating part 101, a fixing part 102, a slip ring 103, a parameter determining part 104, a model acquiring part 105, and a signal transmission control part 110. For the sake of simplicity, the illustrations relating to the rotating part 101, the fixing part 102, and the slip ring 103 of the CT gantry 1 of the first embodiment are omitted, and only the parameter determining part 104, the model acquiring part 105, and the signal transmission control part 110 are shown.

[0071] Furthermore, the rotating part 101, the fixing part 102, the slip ring 103, the parameter determining part 104, and the signal transmission control part 110 are all the same as in the first embodiment, and their descriptions are omitted here.

[0072] The model acquisition unit 105 acquires the channel estimation data model using a non-blind channel estimation method. The non-blind channel estimation method is an estimation algorithm based on a reference signal. This type of algorithm determines the parameters to be estimated according to certain estimation criteria, or it progressively tracks and adjusts the estimated values ​​of the parameters according to certain criteria. Its characteristic is that it requires the use of a reference signal, i.e., a pilot signal or training sequence. In this invention, the channel estimation data model is acquired and stored in advance by the model acquisition unit 105 for use by the parameter determination unit 104.

[0073] For example, the model acquisition unit 105 can insert known pilot symbols and / or sequences into the communication signal at the transmitting end, extract the pilot symbols and / or sequences at the receiving end, perform channel estimation calculations to acquire channel parameters, and acquire a channel estimation data model based on the acquired channel parameters.

[0074] Alternatively, the model acquisition unit 105 can transmit known pilot symbols and / or sequences at the signal transmitting end, extract the pilot symbols and / or sequences at the receiving end, perform channel estimation calculations to acquire channel parameters, and acquire a channel estimation data model based on the acquired channel parameters.

[0075] Below, in conjunction with Figure 4 and Figure 5 The method for channel parameter estimation by the model acquisition unit 105 of the present invention will be described.

[0076] (Example 1)

[0077] Figure 4 This is a schematic diagram illustrating one method of channel parameter estimation according to the present invention. Figure 4In the example shown, as is well known, channel estimation is the process of estimating the model parameters of a hypothetical channel model from the received data. That is, channel estimation is a mathematical representation of the influence of the channel on the input signal, and an ideal channel estimation algorithm is an estimation algorithm that minimizes a certain estimation error.

[0078] For example, the minimum variance (LS) algorithm can be used to estimate the channel parameters based on the pilot location.

[0079] The theoretical formula for the LS algorithm is as follows:

[0080]

[0081] Among them, X p For a certain pilot data to be transmitted, Y p This is the received signal at that pilot position, i.e., the signal demodulated by the receiver. This is the estimated channel response value at the pilot location.

[0082] Assuming the number of subcarriers is n, D(k) is a data sequence, and X... p (m) is the pilot sequence, k+m=n. For example... Figure 4 As shown, after signal D(k) is sent, the modulated signal S(k) is obtained by PLC1 modulation.

[0083] Then, a known pilot sequence X is inserted at a specified position on S(k). p (m) to obtain the signal S(k)+X p (m), the pilot sequence X that was inserted p The position of (m) is the pilot position.

[0084] Then, the signal S(k)+X p (m) via channel H p (n) After transmission, the pilot position received signal Y is demodulated and extracted by PLC2 at the receiving end. p (m).

[0085] Then, the pilot channel response can be obtained using the theoretical formulas of the LS algorithm. That is,

[0086]

[0087] Then, interpolation was used to calculate the results based on the pilot channel response. Capable of recovering the complete frequency band channel response at a certain angular position The CT gantry rotates at a specific speed v, traversing 360°. At each sampling angle, the complete frequency band channel response at that location can be obtained. Then, by using interpolation, the channel response for all angles under velocity v is obtained, thus recovering the complete channel response for all velocities and angles.

[0088] (Example 2)

[0089] Figure 5 This is a schematic diagram illustrating another method of channel parameter estimation for the present invention. Figure 5 In the example shown, the basic principle is roughly the same as in Example 1, but considering that the channel estimation parameters are obtained in advance, it is possible to use only pilot data instead of sending useful data, and adopt the full-band channel estimation method.

[0090] For example, the minimum variance (LS) algorithm can also be used to estimate the channel parameters at the pilot location.

[0091] The theoretical formula for the LS algorithm is as follows:

[0092]

[0093] In this embodiment, X p For a certain pilot data to be transmitted, Y p The received signal at this pilot position is the demodulated signal at the receiver. This is the estimated channel response value at the pilot location.

[0094] Assuming the number of subcarriers is n, and all subcarriers are set as pilot data, the sequence X is obtained. p (n). Since it is a known sequence, modulation is not required; a fixed sequence X can be stored at the transmitting end. p (n) The sampled points after IFFT calculation are sent directly.

[0095] Specifically, such as Figure 5 As shown, during channel parameter estimation, a known sequence X is transmitted. p (n), X p (n) via channel H p (n) After transmission, the received signal Y is demodulated and extracted by PLC2 at the receiving end. p (n).

[0096] Then, the complete frequency band channel response at a certain angle can be directly obtained using the theoretical formulas of the LS algorithm. That is,

[0097]

[0098] The CT gantry rotates at a specific speed, traversing 360°. At each sampling angle, the complete frequency band channel response at that location can be obtained. Then, by using interpolation, the channel response for all angles under velocity v is obtained, thus recovering the complete channel response for all velocities and angles.

[0099] Below, in conjunction with Figure 6 This describes the process by which the model acquisition unit 105 acquires the channel estimation data model. Figure 6 This is a schematic diagram illustrating the process of obtaining the channel estimation data model.

[0100] like Figure 6 As shown, in this invention, when the CT gantry 1 has multiple rotation speeds, the model acquisition unit 105 acquires channel parameters at multiple predetermined positions at intervals of predetermined rotation angles for each of the multiple rotation speeds, and acquires the channel estimation data model.

[0101] For example, when the CT gantry is set to have multiple rotational speeds v, such as 1.5 s / r, 1.0 s / r, 0.75 s / r, 0.6 s / r, and 0.5 s / r, the channel parameters for the CT gantry rotating at 0.1° intervals within the range of 0° ≤ θ < 360° are as follows. The collection of parameters is called the channel estimation data model.

[0102] Furthermore, in order to obtain a high-precision channel estimation data model, the model acquisition unit 105 performs channel parameter acquisition at each predetermined position for each of the various rotation speeds a predetermined number of times. Here, the predetermined number of times is, for example, 15 times. Of course, this predetermined number of times can be appropriately changed as needed.

[0103] When channel parameters are collected more than a specified number of times, the collected channel parameters are combined with the collection results of each rate and each rotation angle to form a channel estimation data model.

[0104] In addition, since the CT gantry transmission is a full-duplex communication, the channel parameter acquisition includes the acquisition of channel parameters from the fixed part 102 to the rotating part 101, and the acquisition of channel parameters from the rotating part 101 to the fixed part 102.

[0105] That is, for the CT gantry, for each rotation speed, within the rotation angle range of 0°≤θ<360°, channel estimation parameters are obtained for the channel from the fixed part to the rotating part and the channel from the rotating part to the fixed part. and They are then stored separately in non-volatile memory to form a channel estimation data model.

[0106] According to the second embodiment, the technical effects of the first embodiment described above are achieved. The channel estimation data model is acquired by the model acquisition unit 105 and then called by the parameter determination unit 104. In this way, the actual communication channel estimation parameters corresponding to the communication signal are determined based on the pre-established channel estimation data model. Furthermore, the channel estimation data model can be acquired simply by collecting channel parameters, without the need for training, thereby improving the transmission speed.

[0107] In addition, the model acquisition unit 105 acquires channel estimation parameters and obtains channel estimation data models for the channels from the fixed part to the rotating part and from the rotating part to the fixed part, respectively. This allows for the establishment and application of channel estimation data models that are more realistic, thereby further improving transmission quality, transmission stability, and transmission speed, and enhancing the transmission performance of the CT gantry.

[0108] (Third Implementation)

[0109] The CT stand 1B of the third embodiment of the present invention will now be described.

[0110] The CT gantry 1B of the third embodiment of the present invention includes a rotating part 101, a fixing part 102, a slip ring 103, a parameter determining part 104, a model acquiring part 105, a measuring part 106, and a signal transmission control part 110.

[0111] The rotating part 101, the fixing part 102, the slip ring 103, the parameter determining part 104, the model acquiring part 105, and the signal transmission control part 110 are all the same as in the first embodiment, and the illustrations and descriptions are omitted here.

[0112] The measuring unit 106 is used to measure the rotation angle. When the signal is transmitted from the rotating unit 102 to the fixed unit 102, considering the real-time error of the acquired rotation angle, it is preferable that the measuring unit 106 is mounted on the rotating unit 101.

[0113] Furthermore, the measuring unit 106 can be a combination of a gyroscope and an accelerometer, a dual-axis tilt sensor, or an encoder, as described below. Figures 7-9 Explanation will be provided. In Figures 7-9 Only a portion of the CT stand 1C is shown in the image.

[0114] (Example 1)

[0115] Figure 7 This is a schematic diagram illustrating Embodiment 1 for obtaining the rotation angle.

[0116] like Figure 7 As shown, in Embodiment 1, the measuring unit 106 is a combination of a gyroscope and an accelerometer.

[0117] In addition, considering the real-time error of the acquired rotation angle, it is preferable that the sensor for measuring the rotation angle is mounted on the rotating part 101.

[0118] By combining a gyroscope and an accelerometer, the rotation angle of the rotating part 101 can be measured in real time. This further simplifies the calculations required for signal transmission, thereby improving transmission speed and performance.

[0119] (Example 2)

[0120] Figure 8 This is a schematic diagram illustrating Embodiment 2 for obtaining the rotation angle.

[0121] like Figure 8 As shown, in Embodiment 2, the measuring unit 106 is a dual-axis tilt sensor. The real-time rotation angle of the rotating part is obtained by the dual-axis tilt sensor.

[0122] In addition, when using a dual-axis tilt sensor to measure dynamic tilt angle, it is preferable to use a combination of two dual-axis tilt sensors to avoid interference from centrifugal force caused by rotation.

[0123] In addition, two identical dual-axis tilt sensors are mounted on the rotating part 101 with their sensitive axes in opposite directions and the same distance between their coaxial centers.

[0124] (Example 3)

[0125] Figure 9 This is a schematic diagram illustrating Example 3 for obtaining the rotation angle.

[0126] like Figure 9 As shown, in Embodiment 3, the measuring unit 106 is an encoder, such as a photoelectric rotary encoder or a magnetoelectric rotary encoder.

[0127] Taking the magnetoelectric rotary encoder mentioned above as an example, the magnetoelectric rotary encoder is mounted on the rotating part of the CT gantry and includes a magnetoelectric induction unit, a rotating magnet, and an external microprocessor. The magnetoelectric induction unit is positioned on the controlled object and generates a voltage based on changes in the magnetic field on the surface of the controlled object, thereby deriving the encoded value of the controlled object's rotation angle. The rotating magnet is mounted non-contactly above the magnetoelectric induction unit, and its axial position remains fixed. The external microprocessor is connected to the magnetoelectric induction unit and reads the coded rotation angle value calculated by the magnetoelectric induction unit.

[0128] According to the third embodiment, it possesses the technical effects of the first and second embodiments described above. By obtaining channel estimation parameters based on the platform's rotation speed and angle through a PLC device, the channel estimation parameters can be predicted before signal transmission, thereby ensuring high transmission quality. Furthermore, since the channel estimation parameters can be predicted in advance, and information is transmitted using these pre-predicted parameters, theoretically, the transmission speed can be increased from 400Mbps to 750Mbps.

[0129] Furthermore, in the third embodiment of the CT gantry 1B, the measuring unit 106 is installed on the rotating unit 101. When the signal is transmitted from the rotating unit 101 to the fixed unit 102, the rotation angle can be obtained directly from the rotating unit 101. Compared with the rotation angle obtained from the rotary encoder (not shown) of the fixed unit 102, the real-time error of the rotation angle acquisition can be reduced, thereby improving the signal transmission speed and stability.

[0130] In addition, the CT gantry 1B of the third embodiment includes a measuring unit 106. The sensor or encoder of the measuring unit 106 for acquiring the rotation angle are mature technologies with simple structure and low cost. The PLC baseband SOC chip is already a mature product. This invention only needs to improve the software part, which is easy to develop and manufacture.

[0131] Furthermore, in the third embodiment of the CT gantry 1B, the sensor for acquiring the rotation angle is small in size and can be integrated into the PLC transmission system. The PLC uses a slip ring for transmission, eliminating the need for additional components and saving space on the CT gantry. The encoder is a separate component; only an interface needs to be reserved on the PLC base plate for transmission.

[0132] In addition, the CT gantry 1B of the third embodiment has extremely low power consumption of the sensor or encoder that acquires the rotation angle, and the acquisition of channel estimation parameters is only a software-level development and will not bring additional power consumption to the PLC equipment, so the equipment power consumption is low.

[0133] As described above, the implementation of the technical concept of the present invention via a CT gantry has been explained. Furthermore, the technical concept of the present invention can also be implemented using a signal transmission method of a CT gantry, a CT apparatus, and a storage medium.

[0134] The CT apparatus according to an embodiment of the present invention includes the CT stand described above.

[0135] The present invention discloses a signal transmission method for a CT gantry, the CT gantry comprising: a rotating part for rotating an X-ray tube and a detector; a fixed part for supporting the rotating part; and a slip ring for transmitting power and transmitting communication signals based on power line carrier communication between the rotating part and the fixed part. The signal transmission method for the CT gantry includes: a parameter determination step, which determines actual communication channel estimation parameters corresponding to the communication signal based on a channel estimation data model according to the rotation speed and rotation angle of the rotating part of the CT gantry at the time the communication signal is transmitted; and a signal transmission control step, which performs control to modulate / demodulate the communication signal using the actual communication channel estimation parameters, thereby transmitting the communication signal.

[0136] Furthermore, the storage medium of the embodiments of the present invention stores, in a computer-readable manner, a program that causes the CT gantry described in any of the above claims to perform the following processes: parameter determination processing, which determines, based on a channel estimation data model, actual communication channel estimation parameters corresponding to the communication signal according to the rotation speed and rotation angle of the CT gantry rotating part at the time the communication signal is transmitted; and signal transmission control processing, which performs control to modulate / demodulate the communication signal using the actual communication channel estimation parameters, thereby transmitting the communication signal.

[0137] Furthermore, the signal transmission method, CT device, and storage medium of the CT gantry according to the above embodiments of the present invention, like the CT gantry described above, can achieve simple structure, low cost, low power consumption, stable data transmission, and fast data transmission speed.

[0138] The foregoing has described several embodiments and examples of the present invention. However, these embodiments and examples are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, and are included within the scope of the invention as described in the claims and its equivalents.

Claims

1. A CT scanner stand, comprising: The rotating part, which carries an X-ray tube and a detector, rotates. The fixed part supports the rotating part; A slip ring for transmitting power and communication signals based on power line carrier communication between the rotating part and the fixed part; The parameter determination unit determines the actual communication channel estimation parameters corresponding to the communication signal based on the channel estimation data model, according to the rotation speed and rotation angle of the CT gantry rotation unit at the moment the communication signal is transmitted. as well as The signal transmission control unit performs control to modulate / demodulate the communication signal using the actual communication channel estimation parameters, thereby transmitting the communication signal.

2. The CT stand according to claim 1, It also includes a model acquisition unit, which acquires the channel estimation data model through a non-blind channel estimation method.

3. The CT stand according to claim 2, The model acquisition unit inserts known pilot symbols and / or sequences into the communication signal at the signal transmitting end, extracts the pilot symbols and / or sequences at the receiving end, performs channel estimation calculations to acquire channel parameters, and acquires the channel estimation data model based on the acquired channel parameters.

4. The CT stand according to claim 2, The model acquisition unit transmits known pilot symbols and / or sequences at the signal transmitting end, extracts the pilot symbols and / or sequences at the receiving end, performs channel estimation calculations to acquire channel parameters, and acquires the channel estimation data model based on the acquired channel parameters.

5. The CT stand according to claim 3 or 4, When the CT gantry has multiple rotation speeds, the model acquisition unit collects channel parameters at multiple predetermined positions at intervals of predetermined rotation angles for each of the multiple rotation speeds.

6. The CT stand according to claim 5, The model acquisition unit performs channel parameter acquisition a specified number of times at each of the multiple rotation speeds and at each specified position.

7. The CT stand according to claim 3 or 4, The channel parameter acquisition includes channel parameter acquisition from the fixed part to the rotating part, and channel parameter acquisition from the rotating part to the fixed part.

8. The CT stand according to claim 1, The channel estimation data model is constructed before the CT stand leaves the factory and is updated periodically after leaving the factory.

9. The CT stand according to claim 1, When transmitting communication signals from the fixed part to the rotating part, the rotation angle is obtained by a rotary encoder provided on the fixed part.

10. The CT gantry according to claim 1, It also includes a measuring unit disposed on the rotating part, and the rotation angle is obtained by the measuring unit when a communication signal is transmitted from the rotating part to the fixed part.

11. The CT stand according to claim 10, The measuring unit is any one of the following: a combination of a gyroscope and an accelerometer, a dual-axis tilt sensor, or an encoder.

12. A CT apparatus comprising a CT stand according to any one of claims 1 to 11.

13. A signal transmission method for a CT gantry, the CT gantry comprising: The rotating part, which carries an X-ray tube and a detector, rotates. The fixed part supports the rotating part; A slip ring for transmitting power and communication signals based on power line carrier communication between the rotating part and the fixed part; The signal transmission method of the CT gantry includes: The parameter determination step involves determining the actual communication channel estimation parameters corresponding to the communication signal based on the rotation speed and rotation angle of the CT gantry rotating part at the moment the communication signal is transmitted, using a channel estimation data model. as well as The signal transmission control step involves controlling the transmission of the communication signal by using the actual communication channel estimation parameters for modulation / demodulation.

14. A storage medium storing, in a computer-readable manner, a program that causes the CT gantry according to any one of claims 1 to 11 to perform the following processing: The parameter determination process involves determining the actual communication channel estimation parameters corresponding to the communication signal based on the rotation speed and angle of the CT gantry rotating part at the moment the communication signal is transmitted, using a channel estimation data model. Signal transmission control processing is performed to control the modulation / demodulation of the communication signal using the actual communication channel estimation parameters, thereby transmitting the communication signal.

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