CN114553311A - Multi-light-path transmission calibration system and method for CT machine - Google Patents

Abstract

The application provides a multi-light-path transmission calibration system and method for a CT machine, and relates to the technical field of communication of CT equipment. The transmission calibration system consists of a transmitting end CT equipment end transmitting optical signal arranged on the inner wall of the CT rotor and a wide-angle receiving optical lens group, a small compensating lens, a light spot monitoring camera, a wavelength spectroscope, a small nutation compensating lens, a communication optical fiber coupler, an optical fiber power detector and the like arranged on a receiving end. The calibration process of three stages of light emission and receiving end initialization establishment, light spot dynamic stabilization and dynamic optical fiber coupling on the rotor of the CT machine is completed, and guarantee is provided for establishment of stable optical information transmission of the rotary joint of the CT machine.

Description

A multi-optical transmission calibration system and method for CT machine

technical field

The invention belongs to the technical field of medical equipment communication information, and relates to a multi-optical path transmission calibration system and method for CT machines.

Background technique

CT (Computed Tomography), that is, electronic computed tomography, which uses precisely collimated X-ray beams, gamma rays, ultrasonic waves, etc., together with a highly sensitive detector, makes a cross-sectional scan around a certain part of the human body one by one. It has the characteristics of fast scanning time and clear images, and can be used for the inspection of various diseases; according to the different rays used, it can be divided into: X-ray CT (X-CT) and γ-ray CT (γ-CT).

Workflow of CT equipment: The scanning part is composed of X-ray tube, detector and scanning frame, which rotates and scans the human body, and the X-ray detector receives the signal; then the information data collected by the scan is transmitted to the computer system for storage and calculation; Finally, the CT images are displayed through the computer-processed and reconstructed images. However, for the principle of CT, images must be obtained by scanning, and now it is developed to spiral CT scan (spiral CT scan). Therefore, faced with the problem of information transmission of rotary joints, at this stage, capacitive non-contact transmission of information is used. This transmission method has a limited rate, and needs to develop a large enough radiating antenna, which requires volume power consumption.

2003 was a period of rapid development of multi-slice spiral CT. At the annual meeting of the Radiological Society of North America, 32-slice and 40-slice were launched by different manufacturers. In 2004, 64-slice spiral CT was a new bright spot in the development of CT. GE, Philips, Siemens, and Toshiba successively released 64-slice CT. The advent of 64-slice spiral CT opened a new era of non-invasive diagnosis of cardiovascular diseases. It can be used in less than 5 seconds. Cardiac scans were completed within the time limit, and cardiac CT became routine clinical practice. Now the scanning time of multi-slice spiral CT has been shortened to sub-second level, and multi-slice spiral CT has been widely used in many fields such as angiography imaging, cerebral perfusion imaging, cardiac imaging, etc. In addition, it is also used in radiation therapy planning and virtual Speculum technology and other aspects play an important role. In 2004, Toshiba was the first to successfully develop a 256-slice spiral CT. Since 2005, a large number of high-end medical CTs have been successfully developed. Its main representatives are: Siemens' dual-source helical CT, Philips' 256-slice ultra-fast CT, Toshiba's 320-slice 640-slice CT, and GE's gem CT.

In the future, the CT data transmission mode will be mainly optical transmission, and the data rate will be further increased to 50Gbps due to the overall technical improvement of CT products. At present, this transmission rate can only be achieved by optical transmission. Both Shrevelling and Mogo are conducting research on optoelectronic transmission, and Shrefering and Mogo have successively launched 10Gbps CT slip ring products.

The digital diagnosis and treatment equipment research and development project "256-row 16-cm high-definition high-speed large-volume medical CT system and core technology research and development", develops a 10Gbps optical transmission system, which is applied to the CT host to arrange 12 channels of transmission, using the circular motion of the mirror cavity to receive, The complexity of the system has a relatively large change in the existing CT equipment, and also has a relatively large impact on the hollow position of the CT.

In the prior art, there is no multi-optical transmission calibration system and method without CT equipment rotating joints.

SUMMARY OF THE INVENTION

The technical problem solved by the present invention is: the data volume collected by CT equipment is getting larger and larger at this stage, the data transmission relying on single-channel capacitive wireless contact has gradually entered the bottleneck, and the transmission demand of higher speed and low cost has become obvious. The invention solves the problem of multi-channel high-speed CT equipment detection information transmission. Under the premise of not changing the internal layout of the CT host, the CT equipment installs a standardized multiplexing interface, and transmits high-speed data to a location outside the host by using an optical carrier. To receive, in the receiving process, it is necessary to first perform the installation and calibration process of the transceiver.

Embodiments of the present application provide a multi-optical transmission calibration system for a CT machine, which relates to the technical field of communication of CT equipment. It includes an optical signal transmitting end and an optical signal receiving end. The transmitting end includes a laser light source, a photoelectric modulator, a beam collimator, WIFI transceiver and supporting structures; the optical signal receiving end includes a wide-angle receiving optical lens group, a small compensation mirror, and a spot monitoring camera. , wavelength beam splitter, micro nutation compensation mirror, communication fiber coupler, fiber power detector and fixed installation platform. The optical signal transmitting end installed on the inner wall of the CT rotor transmits the signal, transmits a certain distance, and reaches the optical signal receiving end, and the optical signal receiving end is located in the middle of the fixed installation platform connected with the CT stator connecting rod. Calibration process. The present application completes the calibration procedure of three stages of optical transmitter and receiver initialization, spot dynamic stabilization and dynamic optical fiber coupling on the CT machine rotor, and provides guarantee for the establishment of the stable optical information transmission of the CT machine rotary joint.

Optionally, it also includes a laser communication emission system, which includes an integrated light source, a photoelectric modulator, a beam splitter, a beam collimator, and a micro position detection module, which is specifically installed on the rotor of the CT host, and the raw data obtained by X-ray detection. Or the data after microwave modulation can be loaded onto the light wave using photoelectric direct modulation technology, and the loading of data is carried out according to the instructions. The detection module is to detect whether there is an indication of the received retrospective light, and the different apertures are installed in close parallel with the beam collimator.

Optionally, it also includes that the wide-angle receiving lens group is used to receive the beam emitted by the laser communication transmitting system, an optical corner reflector is placed in the middle of the protective lens in the wide-angle lens group, and the periphery is coated with a transmission film, and the converged and emitted light is projected onto the tiny compensation mirror, and the incident light is The beam on the corner reflector is reflected along the original optical path to the miniature position detection module of the laser communication transmitting system.

Optionally, it also includes that the spot monitoring camera receives the light reflected by the tiny compensation mirror and then separates the calibration light through the beam splitter. According to the rotation of the laser communication transmitting system with the CT host, the spot monitoring camera receives the spot will also rotate. , the light spot is stabilized on the center of the rotating light spot ring by using the receiving tiny compensation mirror.

Optionally, a micro nutation compensation mirror is also included, which reflects the communication beam separated by the beam splitter to the communication optical fiber coupler, and uses the nutation coupling method to make the detection value of the optical fiber power detector dynamic maximum.

Optionally, it also includes a multi-optical transmission calibration method for CT machine, and the specific steps are as follows: The work is started, and the laser communication transmitting system only starts the calibration beam emission, and projects it to the wide-angle receiving lens group of the receiver. , the corner reflector in the receiving lens group will reflect part of the light back to the miniature position detection module in the laser emission system. With the rotation of the CT host, the intensity of the position detection module has been stabilized, indicating that the transceiver beam has been aligned, and then the wifi command is turned on. For the unmodulated communication beam, the closed-loop control of the tiny compensating mirror and the spot monitoring camera makes the spot stable and constant, and then the closed-loop control of the tiny nutation compensating mirror and the fiber power detector is used to suppress the environmental vibration and the instability of the center of mass of the ring halo. and other factors to improve the fiber coupling efficiency. In this way, the calibration process of the multi-optical transmission of the CT machine is completed.

Through laser wireless communication, the high-speed data on the rotor of the CT machine is transmitted to a fixed position for reception, so as to achieve the purpose of optical transmission of the rotating joint of the CT machine. Accurate, use the closed-loop control of the tiny compensation mirror and the spot monitoring camera to eliminate the centroid variation of the circular rotating light spot, so that it is stabilized on the center of the circle. The closed-loop control of the micro nutation compensation mirror and the fiber power detector is used to eliminate the instability of the light spot and the vibration of the environment, and improve the fiber coupling efficiency. This calibration process makes the optical transmission stable and satisfies the multi-channel optical transmission.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention does not change the internal layout of the CT host, but only installs the optical emission module of the standard interface, so that the CT acquisition data is transmitted at a high speed, and the initial alignment method of the retrospective light is used to indicate the initialization of the transceiver. This calibration system not only can It can be equipped for the CT equipment currently in use, or it can be equipped for the CT equipment under development.

(2) The present invention uses the closed-loop control of the tiny compensation mirror and the spot monitoring camera to eliminate the change of the center of mass of the circular rotating light spot, so that it is stable on the center of the circle, and the light spot at the center of the circle is unstable, and then uses the tiny nutation compensation mirror and the optical fiber power detector. The closed-loop control eliminates the instability of the light spot and the vibration of the environment, and finally improves the fiber coupling efficiency.

Description of drawings

In order to illustrate the specific embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that are required in the description of the specific embodiments or the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. In the drawings, each element or section is not necessarily drawn to actual scale.

1 is a diagram of a multi-optical transmission calibration system provided by an embodiment of the present invention;

2 is a flowchart of a multi-optical transmission calibration method provided by an embodiment of the present invention;

Fig. 3 is the calibration system diagram of the multi-optical path wavelength division multiplexing communication mode provided by the embodiment of the present invention;

Detailed ways

Embodiments of the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the usual meanings understood by those skilled in the art to which the present invention belongs.

As shown in FIG. 1, an embodiment of the present invention provides a diagram of a multi-optical transmission calibration system for CT machines, which is applicable to a multi-optical transmission calibration system for CT machines, and is characterized in that it includes: a CT host 1. Laser communication transmitting system 2, wide-angle receiving mirror group 3, tiny compensation mirror 4, beam splitter 5, spot monitoring camera 6, tiny nutation compensation mirror 7, communication fiber coupler 8, fiber power detector 9, optical angle reflection 10 , a micro position detection module 11 , a fixed installation platform 12 and a communication receiving module 13 . Among them, the laser communication emission system 2 is installed on the side wall of the scanning rotor of the CT host 1, which includes the emission of multiple communication beams, the emission of calibration beams and the micro position detection module of the retrospective light, which The multiplexing of X-ray detection and acquisition is 1 channel of original digital data, or it has been converted into a microwave intermediate frequency signal and modulated onto an optical carrier, or the X-ray multi-channel acquisition data is directly loaded into the laser communication transmission system 2 by optical multiplexing and multiplexing. In short, this module can be changed at will according to the design and is not limited by the system method. The emitted light beam is projected to the receiver. The central axis of the receiver is on the central Z axis of the CT main body 1. The retrospective light of the optical corner reflector 10 installed at the front end of the wide-angle receiving mirror group 3 determines whether the received and received light beams have been aligned. This alignment method is used in the initialization process of the communication transmission self-check of the CT equipment. The micro-position detection module 11 for discriminating the retrospective light with different apertures is installed in close parallel with the beam collimator in the laser communication transmitting system 2 . The calibration beam divergence angle is larger than the communication beam divergence angle, the CT host 1 moves in a circle, and the presence or absence of the light spot is determined according to the micro position detection module 11 to adjust the direction of the laser communication transmitting system 2. This adjustment is relatively simple and no longer necessary. Repeat.

The wide-angle receiving lens group 3 adopts a 360° panoramic imaging optical system and adopts a telephoto convergence method. The light beam needs to be reflected by the small compensation mirror 4, and the reflected light beam passes through the wavelength beam splitter 5 to separate and transmit the calibration beam to the spot monitoring camera 6. The focus of the calibration beam is at the spot monitoring camera 6, and the reflected beam is a communication beam with multiple bands of 1.3um, 1.5um, and 1.06um. Calculate the spot of the calibration beam projected on the monitor camera 6, and calculate the spot centroid. , according to the circular motion of the light spot, the center of mass is connected into a circular ring, and the center of the circle is calibrated according to the circular ring. Due to the installation accuracy of the receiver and the flatness accuracy of the fixed installation platform 12 and many other engineering construction factors, the center of the circle is not very fixed. Therefore, by adjusting the tiny compensating mirror 4, the spot is dynamically stabilized at the center of the circle, and the angle of the uncertain axis corresponding to the spot at the center of the circle is α,

The micro nutation compensation mirror 7 uses the fiber coupling nutation method. First, the helical scanning is started, and the axial angle of the scanning is 1.5α. The light coupled into the communication fiber coupler 8 passes through the fiber power detector 9 to detect the coupled light power. Until the maximum optical power is reached, the influence of environmental vibration, temperature and humidity changes on the optical coupling can be reduced.

The demand for CT data transmission will be higher and higher, and the optical communication adopts wavelength division multiplexing as shown in Figure 3. The wavelength beam splitter 5 continuously decomposes the parallel multi-wavelength nutation coupling mode, which can realize higher rate CT data transmission. need. Of course, more efficient bandwidth communication methods are also applicable in this system. This system realizes the calibration process before the establishment of the new optical channel, and it has little correlation with which communication modulation and demodulation method is adopted.

As shown in FIG. 2, the optical transmission flow chart of the rotating joint of the CT equipment provided by the embodiment of the present invention is applicable to a multi-optical transmission calibration method for a CT machine. The transmitter of the system is on the rotor of the CT host 1. The receiver is on the Z axis of the CT host, so there is a calibration process for the beam in different places. The calibration process must be required before the complete communication is established. The specific implementation steps are as follows:

(1) The work starts. As shown in Figure 3, the laser communication transmitting system 2 has been installed on the rotor of the CT host 1. The WiFi command informs the start of the emission calibration beam. The divergence angle of the beam is relatively large relative to the communication beam. The wavelength of the calibration beam is 800nm, and the emission beam is projected on the protective mirror of the wide-angle receiving lens group.

(2) The projected beam part is backtracked in the optical corner reflector 10, the size of the corner reflector is 6.2mm, according to whether the micro-position detection module 11 receives the back-tracking light with or without light, if there is no light, adjust the laser communication transmitting system 2, so that the micro-position The detection module 11 has light, and then the WiFi command notifies the laser to turn on the unmodulated communication beam, and the CT host 1 also turns on and rotates.

(3) The calibration beam and the communication beam pass through the wavelength beam splitter 5, and the transmitted calibration beam is 800nm. The reflected beam is the communication beam in multiple bands of 1.3um, 1.5um and 1.06um. The spot monitoring camera 6 follows the center of the spot mass. The position of the circular ring of the spot is calibrated, thereby determining the uncertain area of the center of the circle. The tiny compensation mirror 4 adopts a MEMS two-dimensional rotating mirror, and the resonant frequency of the rotating mirror is 5KHz. in an uncertain area.

(4) When the light spot has reached the uncertainty area of the light spot, the corresponding axial uncertainty angle is α, the micro nutation compensation mirror 7 is turned on, and within the axial angle range of the light spot monitoring camera 6 of 1.5α, the axis starts from the axis. Helical scanning from the inside to the outside, the scanning pitch is 3urad, the micro nutation compensation mirror also uses a MEMS mirror, the frequency is 5kHz, the optical fiber power detector 9 continuously detects the power and the optical power is stored according to the maximum value position, and then uses this as the center of the axial angle The spiral scanning is performed from the inside to the outside, and the scanning range is to ensure that the power of the optical power detector 9 is maximized, and repeating this can ensure the stable coupling efficiency of the optical power.

(5) Then the WiFi command notifies the laser modulation communication beam to be turned on, and the CT host 1 can collect data and work normally, and then go to (3).

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. The scope of the invention should be included in the scope of the claims and description of the present invention.

Claims (6)

1. a multi-optical transmission calibration system for CT machine, solves the problem of real-time data transmission in the medical CT scanning process, is characterized in that comprising: CT host (1), laser communication transmitting system (2), wide-angle receiving mirror group (3), tiny compensation mirror (4), beam splitter (5), spot monitoring camera (6), tiny nutation compensation mirror (7), communication fiber coupler (8), fiber power detector (9), optical fiber A corner reflector (10), a miniature position detection module (11), a fixed installation platform (12) and a communication receiving module (13). 2. A kind of multi-optical transmission calibration system for CT machine according to claim 1, it is characterized in that: described laser communication launch system (2) comprises integrated light source, photoelectric modulator, beam splitter, beam calibrator The straight device and the micro position detection module are specifically installed on the rotor of the CT host (1). The raw data of the data obtained by the X-ray detection or the data after microwave modulation can be loaded onto the light wave using the photoelectric direct modulation technology, and loaded The data is carried out according to the instructions, the beam splitter is to combine the modulated beam of the multi-channel laser source and the calibration beam, the micro position detection module (11) is to detect whether there is an indication of the received retrospective light, and the different aperture is closely related to the beam collimator. Installed in parallel. 3. a kind of multi-optical transmission calibration system for CT machine according to claim 1 is characterized in that: described wide-angle receiving mirror group (3) is to receive the light beam emitted by laser communication transmitting system (2), An optical corner reflector (10) is placed in the middle of the protective lens in the wide-angle lens group, and the periphery is coated with a transmissive film. The concentrated and emitted light is projected on the tiny compensation mirror (4), and the light beam incident on the corner reflector is reflected to the laser communication along the original optical path. on the miniature position detection module (11) of the transmitting system (2). 4. A kind of multi-optical transmission calibration system for CT machine according to claim 1, it is characterized in that: what described spot monitoring camera (6) receives is the light after the reflection of tiny compensating mirror (4) and then After the calibration light separated by the beam splitter (5), according to the laser communication transmitting system (2) with the rotation of the CT host (1), the light spot monitoring camera (6) receives the light spot will also rotate, using the receiving tiny compensation mirror (4) ) to stabilize the spot on the center of the rotating spot ring. 5. a kind of multi-optical path transmission calibration system for CT machine according to claim 1, is characterized in that: described tiny nutation compensation mirror (7) is to reflect the communication beam separated by beam splitter (5) To the communication optical fiber coupler (8), the detection value of the optical fiber power detector (9) is dynamically maximized by means of nutation coupling. 6. a kind of multi-optical transmission calibration method for CT machine is characterized in that, this method comprises: adopting the multi-optical transmission calibration system as described in any one of claim 1-5, and concrete steps are as follows: When the work starts, the laser communication transmitting system (2) only turns on the calibration beam emission, and after projecting to the wide-angle receiving lens group (3) of the receiver, the corner reflector in the receiving lens group will reflect part of the light back into the laser transmitting system The miniature position detection module (11) keeps the intensity of the position detection module stable with the rotation of the CT host (1), indicating that the sending and receiving beams have been aligned, and then the wifi command turns on the unmodulated communication beam, and uses the tiny compensation mirror (4) The closed-loop control of the spot monitoring camera (6) and the spot monitoring camera (6) make the spot stable and constant, and the closed-loop control of the tiny nutation compensation mirror (7) and the optical fiber power detector (9) is used to suppress the environmental vibration and the instability of the center of mass of the ring halo, etc. factor, and improve the fiber coupling efficiency, thus completing the calibration process of the multi-optical transmission of the CT machine.

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