A CT detector data slip ring intermittent transmission method and system

Abstract

The present invention discloses a method and system for intermittent transmission of CT detector data via a slip ring. The method includes: a host configuring data buffer location information for the detector; the detector collecting data; pausing CT image data transmission when the gantry approaches the data buffer location, caching the CT image data, and resuming CT image data transmission when the gantry passes the CT image data buffer location. The present invention controls the intermittent transmission of detector data within the gantry rotation cycle, only caching CT image data at the data buffer location, and transmitting CT image data after the data buffer location has passed. Slip ring bit errors are not reflected in the received data, effectively solving the problem of bit errors in specific angle intervals of the slip ring.

Description

Technical Field

[0001] The present invention relates to the technical field of CT detector data transmission, and in particular to a slip ring intermittent transmission method and system for CT detector data. Background Art

[0002] Medical CT imaging involves collecting a series of X-ray exposure data at different gantry rotation angles and reconstructing the tomographic image using algorithms. The following are the shortcomings of detector data transmission in existing technologies:

[0003] First, detector data integrity is paramount to image quality. CT data volumes typically range from hundreds of megabits per second to tens of gigabits per second. Detector data errors or even data loss directly lead to artifacts in the reconstructed image, compromising diagnostics. Therefore, data transmission systems place high demands on slip ring reliability, stability, and electromagnetic compatibility. However, in real-world applications, slip rings can experience transmission errors due to interference from other electronic components on the gantry and other diagnostic or therapeutic equipment within the scanning room, leading to detector data errors. One type of slip ring transmission error occurs at specific angles within the slip ring, with the resulting error rate varying with the strength of the interference source. Shielding the interference source can reduce or even eliminate errors if the source is identified, but CT operating environments vary widely, and this approach has limitations when the interference source is hidden or shielding is difficult to implement. Error-correcting channel coding can also eliminate errors under certain conditions, but this inevitably sacrifices channel capacity, requiring a larger channel bandwidth for the same signal bandwidth. Applying an encoding mechanism at the transmitter requires a corresponding decoding mechanism at the receiver, increasing system complexity and cost. At the same time, the capability of any error correction coding is limited. In poor channel environments, the error-corrected data will still cause image artifacts.

[0004] Second, in the continuous data transmission mode, when the amount of single sampling data is not large, the transmission bandwidth of the slip ring is completely occupied, resulting in low efficiency.

[0005] Third, to meet the data transmission requirements at all angles on the entire circumference, the slip ring antenna is large in size and high in cost. Summary of the Invention

[0006] Technical purpose: In response to the defects in the existing technology, the present invention discloses a CT detector data slip ring intermittent transmission method and system. By controlling the detector data to be sent intermittently within the rack rotation cycle, the data buffer area only caches the CT image data, and the CT image data is sent after the data buffer area position. The slip ring's bit error will not be reflected in the received data, which can effectively solve the slip ring's specific angle range bit error problem.

[0007] Technical solution: In order to achieve the above technical objectives, the present invention adopts the following technical solution.

[0008] A method for transmitting CT detector data in a sliding intermittent loop comprises the following steps:

[0009] The host configures the data buffer location information to the detector;

[0010] The detector collects data, and when the rack approaches the data buffer area, the CT image data transmission is suspended and the CT image data is cached. When the rack passes the CT image data buffer area, the CT image data transmission is resumed.

[0011] Preferably, the data buffer area location information is preset information: the data buffer area location is a location with a high bit error rate during the slip ring data transmission process, or a location where no transmitting antenna is arranged, or a location where channel multiplexing is required.

[0012] Preferably, when used in a scenario where the slip ring has a specific angle of error, the data buffer area is located at a position where the error rate is high during the slip ring sending data. The determination method is: on the circumference of the slip ring, starting from the zero position, the detector performs multiple samplings, and the host finds the error occurrence interval relative to the zero position based on the detector data verification result or the image artifact situation. The error occurrence interval is the data buffer area position.

[0013] Preferably, when applied in a channel multiplexing scenario, the data buffer area location is the location where channel multiplexing is required, and the determination method is: based on the effective bandwidth of the data, the slip ring angle range required for continuous data transmission can be calculated, and the slip ring angle range is the data buffer area location.

[0014] Preferably, during the CT image data buffering process, a data transmission channel is multiplexed to transmit detector parameter information, where the detector parameter information includes detector temperature, working status, and tube focus position.

[0015] Preferably, when used in the scenario of a small-size slip ring antenna, the data cache area is located at a position where no transmitting antenna is arranged, and no transmitting antenna is set at the data cache area. The position of the small-size antenna on the circumference of the slip ring is known, and the angle where no antenna is arranged is the cache period of the detector data, that is, the data cache area position.

[0016] A CT detector data slip-intermittent ring transmission system, used to implement any of the above-mentioned CT detector data slip-intermittent ring transmission methods, comprising: a CT frame, the CT frame comprising a rotating rotor portion and a stationary stator portion, the rotating portion comprising a tube, high voltage, and a detector, and the stationary portion comprising a motor; interaction between the rotating portion and the stationary portion is achieved via a slip ring, the slip ring comprising a carbon brush box and a receiver arranged on the stationary portion of the frame, a transmitter, a power ring, and a signal ring rotating with the rotating portion of the frame; the power ring is used to provide power to components of the rotating portion, and the signal ring is used to transmit control and commands to the rotating and stationary portions; the carbon brush box serves as a transmission channel for signals between the rotating and stationary portions; the transmitter is used to convert detector data into radio frequency signals; the transmitting antenna is used to transmit radio frequency signals; and the receiver is used to receive radio frequency signals and perform electro-optical conversion.

[0017] Preferably, the system further includes a memory for storing cached CT image data.

[0018] Beneficial effect: The present invention controls the detector data to be sent intermittently during the rack rotation cycle, and the data buffer area only caches the CT image data. The CT image data is sent after the data buffer area position has passed. The bit error of the slip ring will not be reflected in the received data, which can effectively solve the bit error problem in the specific angle range of the slip ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a flow chart of the method of the present invention;

[0020] Figure 2 Schematic diagram of the CT gantry structure of the present invention;

[0021] Figure 3 Schematic diagram of the slip ring structure of the present invention;

[0022] Figure 4 This is a schematic diagram of the data sending period of the present invention;

[0023] Figure 5 A schematic diagram comparing a full-size slip ring antenna and a small-size slip ring antenna in the present invention;

[0024] Among them, 1 is the bulb, 2 is high voltage, 3 is the detector, 4 is the motor, 5 is the transmitting antenna, 6 is the receiver, 7 is the carbon brush box, 8 is the power ring, 9 is the signal ring, and 10 is the transmitter. DETAILED DESCRIPTION

[0025] The following further describes and explains a CT detector data slip ring intermittent transmission method and system of the present invention in conjunction with the accompanying drawings.

[0026] As attached Figure 1 and attached Figure 4As shown, a slip ring intermittent transmission method for CT detector data includes the following steps:

[0027] The host configures the data buffer location information to the detector;

[0028] The detector collects data, and when the gantry rotates to a position close to the data buffer area, the CT image data transmission is suspended and the CT image data is cached. When the gantry passes the CT image data buffer area, the CT image data transmission is resumed.

[0029] When the detector does not detect a change in the data cache location information, the working mode remains unchanged until the host configures new data cache location information. During the data collection process, the detector collects data and transmits intermittently according to the new data cache location information.

[0030] The data buffer location information is preset: the data buffer location is a location with a high bit error rate during slip ring data transmission, a location without a transmitting antenna, or a location requiring channel multiplexing. During gantry rotation, a gantry zero position (starting position) is defined. The data buffer location has a positional relationship with the gantry zero position. For example, the data buffer location information is an angular relationship relative to the gantry zero position. During gantry rotation for CT scanning, the detector front-end signal module's output from X-ray conversion is collected. The data collected by the detector includes sampling position information of the gantry's current position relative to the gantry zero position, thereby determining the positional relationship between the gantry's current position and the data buffer location.

[0031] In the present invention, the host computer assigns the position information corresponding to the data buffer period to the detector control board. When the gantry rotates close to this position, the detector control board samples X-ray data normally and buffers the sampled data at this time. After the gantry rotates past the buffer period, the detector control board resumes sending the sampled data to the slip ring detector.

[0032] During the CT image data buffering process, the data transmission channel is multiplexed to transmit detector parameter information, including detector temperature and working status. No transmitting antenna is set at the data buffer area.

[0033] The present invention is mainly applied to the following three scenarios:

[0034] In the scenario where the slip ring has a specific angle error: due to electromagnetic interference between the rack or the scanner, etc., the slip ring has a high error rate at a specific angle. The present invention controls the detector data to be sent intermittently within the rack rotation cycle, which can effectively solve the problem of error in the specific angle interval of the slip ring. The data buffer area position, that is, the position data with error is not sent, but only cached, and then sent after the error position. The error of the slip ring will not be reflected in the received data, so there is no need to worry about the error rate. In this scenario, the data buffer area position is the position with a high error rate during the data transmission process of the slip ring. The determination method is: on the circumference of the slip ring, starting from the zero position, the detector performs multiple samplings, and the host finds the error interval relative to the zero position based on the detector data verification result or the image artifact situation. The error interval corresponds to Figure 4 The detector sampling data buffer period, that is, the data buffer area position. In this scenario, the method of the present invention can effectively solve the angle error of the slip ring, without increasing the hardware cost and without requiring the bit error rate.

[0035] In the scenario of channel multiplexing: During the data caching period, the present invention multiplexes the data transmission channel to transmit information such as detector temperature, working status, and tube focal position. When the rack passes the CT image data cache area position, the CT image data transmission is resumed and channel multiplexing is stopped. In this scenario, the data cache area position is the position where channel multiplexing is required. The slip ring angle range required for continuous data transmission can be calculated based on the effective bandwidth of the data. This range corresponds to the transmission period of the detector data, and the remaining range is the data caching period, and the corresponding position information is the data cache area position. During the detector data caching period, the monitoring information of the detector or rotating system, such as the detector temperature, tube focal position, etc., can be sent to the host through the slip ring. In this scenario, the method of the present invention is used, and when the slip ring bandwidth is higher than the detector data bandwidth, the multiplexing of the transmission channel can be achieved, thereby improving the utilization rate of the slip ring antenna.

[0036] In the application scenario of small-sized slip ring antenna: the current transmitting antenna is arranged on the entire circumference of the slip ring, which is difficult to design and expensive. When using a small-sized slip ring antenna, a data intermittent transmission scheme is adopted. Data can be transmitted only at the location where the transmitting antenna is arranged, and data is cached at the location where the antenna is not arranged, thereby reducing the size of the slip ring transmitting antenna, simplifying the design of the slip ring transmitting antenna, and effectively reducing costs. In this scenario, the data cache area is located at the location where the transmitting antenna is not arranged. The position of the small-sized antenna on the circumference of the slip ring is known, such as Figure 5 As shown, the coverage of the antenna corresponds to Figure 4 The detector sampling data transmission period is shown. Correspondingly, the angles where no antennas are deployed represent the detector data buffering period, i.e., the data buffer location. In this scenario, the method of the present invention eliminates the need to transmit data across the entire circumference, thus simplifying the slip-ring antenna design and reducing costs.

[0037] As attached Figure 2 and attached Figure 3 As shown, a CT detector data slip ring intermittent transmission system is used to implement any of the above-mentioned CT detector data slip ring intermittent transmission methods, as shown in the attached Figure 2 As shown in the figure, the CT frame is divided into a rotating rotor part and a stationary stator part. The rotating part includes a tube 1, a high voltage 2, and a detector 3. The detector 3 is arranged opposite the tube 1, and the high voltage 2 is arranged on the side of the tube 1. The stationary part includes a motor 4. The interaction between the rotating part and the stationary part, such as power supply, control and transmission of sampled data from the detector 3, is usually achieved through slip rings. The structural diagram of the slip ring is shown in the attached figure. Figure 3 As shown, the slip ring includes a carbon brush box 7 and receiver 6 mounted on the stationary portion of the gantry, a transmitter 10, a power ring 8, and a signal ring 9 that rotate with the rotating portion of the gantry. The power ring 8 provides power to the rotating components, and the signal ring 9 transmits control and commands between the rotating and stationary portions. The carbon brush box 7 serves as a signal transmission channel between the rotating and stationary portions. The transmitter 10 converts data sampled by the detector 3 into a radio frequency signal. The transmitting antenna 5 transmits the radio frequency signal. The receiver 6 receives the radio frequency signal and performs electro-optical conversion. During gantry rotation, the detector collects data at different angles, and this data is transmitted via the slip ring to the host computer for subsequent image reconstruction. Existing data transmission schemes transmit collected data to the slip ring as soon as it is ready, with no valid data between data packets.

[0038] The present invention also includes a memory for storing cached CT image data. In one embodiment, the FPGA's internal memory is used to handle small-scale antenna positioning or small-scale slip ring bit errors. External memory is added when more data needs to be cached. The specific usage depends on actual needs.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A CT detector data slip ring intermittent transmission method, characterized by: The following steps are involved: The host configures the data buffer location information to the detector; The detector collects data, and when the gantry approaches the data buffer area, the CT image data transmission is suspended and the CT image data is buffered. When the gantry passes the CT image data buffer area, the CT image data transmission is resumed; The data buffer location information is preset information: the data buffer location is the location where the bit error rate is high during the slip ring data transmission process, or the location where the transmitting antenna is not arranged, or the location where channel multiplexing is required. When used in scenarios where the slip ring has a specific angle of error, the data buffer area is located at the position where the bit error rate is high during the slip ring data transmission process. The determination method is: on the circumference of the slip ring, starting from the zero position, the detector performs multiple samplings, and the host finds the error occurrence interval relative to the zero position based on the detector data verification results or image artifacts. The error occurrence interval is the data buffer area location.

2. The method for intermittent transmission of CT detector data by slip ring according to claim 1, characterized in that: When applied in a channel multiplexing scenario, the data buffer area is located at the location where channel multiplexing is required. The determination method is: calculate the slip ring angle range required for continuous data transmission based on the effective bandwidth of the data. The slip ring angle range is the data buffer area location.

3. The method for intermittent transmission of CT detector data by slip ring according to claim 2, characterized in that: During the CT image data buffering process, the data transmission channel is multiplexed to transmit detector parameter information, which includes detector temperature, working status, and tube focus position.

4. The method for intermittent transmission of CT detector data by slip ring according to claim 1, characterized in that: When used in the scenario of a small-size slip ring antenna, the data cache area is located at a position where no transmitting antenna is arranged. No transmitting antenna is set at the data cache area. The position of the small-size antenna on the circumference of the slip ring is known. The angle where no antenna is arranged is the cache period of the detector data, that is, the data cache area position.

5. A CT detector data slip ring intermittent transmission system, used to implement a CT detector data slip ring intermittent transmission method according to any one of claims 1 to 4, characterized in that: include: The CT frame includes a rotating rotor part and a stationary stator part, the rotating part includes a tube (1), a high voltage (2), and a detector (3), and the stationary part includes a motor (4); the interaction between the rotating part and the stationary part is realized through a slip ring, the slip ring includes a carbon brush box (7) and a receiver (6) arranged on the stationary part of the frame, a transmitter (10), a power ring (8), and a signal ring (9) rotating with the rotating part of the random frame; the power ring (8) is used to provide power to the components of the rotating part, and the signal ring (9) is used to transmit control and commands of the rotating and stationary parts; the carbon brush box (7) is used as a transmission channel for signals of the rotating part and the stationary part; the transmitter (10) is used to convert the data of the detector (3) into a radio frequency signal; the transmitting antenna (5) is used to transmit the radio frequency signal; and the receiver (6) is used to receive the radio frequency signal and perform electro-optical conversion.

6. The CT detector data slip ring intermittent transmission system according to claim 5, characterized in that: The system also includes a memory for storing cached CT image data.

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