Main equipment of interventional operating room

Since the application of digital subtraction angiography (DSA) technology in the 198s, people have gradually got rid of the tedious and complicated imaging methods such as continuous fluoroscopy, random film-spotting, rapid film changer and film film film, and used the advanced technologies such as digital fluoroscopy, digital film and DSA to make the angiography room gradually move from a single radiology diagnosis room to a well-equipped and strictly managed referral operating room. In order to ensure the smooth progress of interventional surgery, the interventional operating room should be equipped with cardiovascular imaging machine, high-pressure syringe, mobile B-ultrasound machine and other equipment.

cardiovascular imaging machine

Modern cardiovascular imaging machine is an indispensable equipment for interventional surgery, which usually consists of X-ray system and computer system. (1) High-quality image quality of X-ray system must have a high-performance X-ray machine, so that patients can be treated accurately and thoroughly. Therefore, a high-performance X-ray machine must have the following characteristics: 1. High power: repeated and repeated continuous exposures are required during the surgery, which requires the X-ray machine to repeatedly output enough power in a short time, so as to obtain satisfactory X-ray images. At present, more than 12mA and 15kV X-ray machines are used. 2. The X-ray tube has a large capacity and a small focus: In order to obtain a satisfactory angiocardiographic image, the smaller the focus of the X-ray tube, the smaller the penumbra and the better the image definition. 3. The pressure emitted by the high-voltage generator should be stable: in order to ensure the consistent quality of each image, besides the consistent irradiation parameters, it is also necessary to ensure a constant high KV value. 4. Short exposure time: Cardioangiography requires continuous exposure for several times to dozens of times within 1 second, and each exposure time is very short. 5. Two sets of host computers: During cardiac angiography, it is required to make oblique projection of the front, side or both sides at the same time, and the two-way photography should be synchronized. It is easy for the two sets of hosts to adjust the irradiation parameters separately, so as to obtain satisfactory cardiac images and shorten the examination time. X-ray system mainly includes X-ray tube, image intensifier, high-voltage generator, console, TV system, C-arm and catheter bed. 1.X-ray tube: X-ray tube with high power (5 ~ 15 kW), high heat capacity and small focus (.4 ~ 1.2 mm) is mainly used to produce X-rays with high kilovolts and short pulses, and high-quality images with more than 5 frames per second can be obtained. 2. Grating and filter plate: Controlling the grating can limit the irradiation field of X-rays to reduce scattered rays, while the filter plate can effectively eliminate soft rays and improve the quality of X-rays. Both of them can limit the generation of low-energy X-rays, reduce the formation of fog and reduce the radiation dose of both doctors and patients. 3. High-voltage generator: In order to ensure the stability of output voltage, three-phase AC 12-pulse or moderate high-voltage generator and other X-ray high-voltage generators with relatively stable ripple are often used. 4. Image intensifier: it receives the X-ray penetrating the inspection site and magnifies it by .6 ~ 1, times, so that the camera can obtain brighter images. Its field of view varies in sizes, such as 6 inches, 9 inches, 11 inches and 14 inches. The larger the diameter, the larger the inspection range can be displayed. Usually, the visual field can be adjusted to adapt to the size of the examination site and obtain the best image. 5. TV camera: it is the part that has the greatest influence on the image resolution. Only when the resolution matrix reaches l24×l24 can the image on the image intensifier be completely converted into video signals for input into the computer system. 6.X-ray console: It can control the switch of X-ray machine, select the focus size and adjust various technical parameters. 7. "C"-shaped arm: it is mainly the base of X-ray tube. By controlling it, it can realize multi-angle projection in vertical, horizontal and arbitrary aspects, so as to fully display the lesions and facilitate the operation. 8. Catheter bed: it can be divided into suspended bed and floor bed, which can move in many directions on the horizontal plane, which is beneficial to the handling of patients and the operation. 9. High-resolution monitor: Its resolution can reach 124×124 matrix, and there are 1 ~ 2 sets in the general operation room and control room respectively, which are used to monitor the acquired and processed images.

(2) Computer system

1. Computer console: it controls and coordinates the completion of each step of radiography, and can call for the application of various digital technologies, digital image adjustment and post-processing. 2. Computer: It converts analog signals obtained by TV cameras into digital signals, obtains high-quality digital images through high-speed operation, amplification and adjustment, and completes the processing, storage, playback and transmission of digital images, which is the advantage of digital images. 3. Analog-to-digital converter (D/A): It converts analog signals obtained by TV cameras into binary numbers and processes them by computer central processor to obtain digital signals. Lossless post-amplification processing, transmission and storage can be carried out. 4. Digital-to-analog converter (A/D): It converts the processed digital signals into analog signals, and forms video images for diagnosis with different gray-scale lattice. 5. Central Processing Unit (CPU): It is the core of the whole equipment, and its function is to process the logical operation of numbers in the system and issue instructions for the operation of various programs. High-performance DSA system is equipped with CPU with fast processing speed. 6. Memory (hard disk): It is used to store the programs and data of DSA system, generally divided into main memory and auxiliary memory. When the main memory is insufficient or fails, the auxiliary memory is supplemented and replaced to complete normal work. 7. Keyboard: It is the bridge between the operator and the machine. Through it, the operator can input the general data of patients into the computer, and call various programs and process images through it. (III) Commonly used digital technology 1. Digital subtraction angiography (DSA): Digital subtraction angiography technology is a technology that digitizes the non-contrast image and the contrast image respectively through machinery and equipment, and then matches and subtracts them by computer to convert them into only vascular images and eliminate the surrounding tissue structure. The application of DSA technology makes people get more clear images with less radiation dose and contrast dose to meet the growing clinical needs. The commonly used methods include pulse mode, continuous mode, time interval difference mode and ECG trigger mode, and the appropriate mode and sequence can be selected according to the patient's condition, lesion site and special requirements to better find the lesion. 2. Digital perspective: After the ordinary perspective technology is digitized, its image can be fixed, replayed and even stored. The application of pulse technology can double the X-ray dose, usually using 1/2 or l/3 coefficient, which can obviously reduce the radiation dose and examination time accepted by operators and patients. 3. Digital film: In the past, the film technology was to project the image on the film. If you want to watch it, you must go through darkroom before you can watch it through the projector. Due to many human factors, the image quality cannot be guaranteed, and you can't watch the effect immediately after contrast, so the storage time is limited. The application of digital technology is to store the image on the hard disk, without many intermediate links, removing many unstable factors, and can increase the exposure speed to 5 frames, seconds or even 75 frames/second, and immediately replay it. The image quality is stable and reliable, and it can be stored for a long time.

High-pressure injector

The application of high-pressure injector can ensure that the required contrast agent can be injected into the patient's cardiovascular system at a certain pressure and flow rate in a short period of time, and the examined part can be filled with high concentration, so as to take a high-contrast image, which can match the exposure of X-ray machine during the imaging process, thus improving the accuracy and success rate of photography. Modern high-voltage devices are mostly controlled by microcomputer, which has the advantages of miniaturization, high control accuracy, stable operation and intelligent operation. (I) Structure and Function The main structure of the high-pressure injector is as follows: 1. Multi-axis moving injection head: it sucks a certain concentration of contrast agent into the injection barrel (disposable), and the total amount of contrast agent in the barrel is detected by a microcomputer and heated to body temperature. Its multi-axis system can move in the direction in coordination with the position of the catheter head to ensure the smooth progress of imaging. 2. Console: It is the center of the high-pressure injector and controls all injection parameters and procedures. 3. Moving support: There are three methods: zenith hanging, catheter bed standing and floor standing. You can choose one according to the user's habits and room structure. Generally, floor-standing is more convenient and practical. (II) Injection parameters In order to obtain a satisfactory contrast image, appropriate parameters must be selected according to the position of the catheter head, the diameter of the catheter, the size of the lesion, and the blood flow running time. The commonly used parameters are as follows: 1. Delay time: according to the needs of lesions, the timing of contrast agent injection is controlled, which is divided into two ways: exposure delay and injection delay. 2. Dose per injection: that is, the contrast dose injected during each contrast, which cannot be mixed with the total amount. Generally in milliliters. 3. Injection flow rate: refers to the contrast dose injected into the catheter per unit time, usually expressed in ml/s.. Each set injection flow rate is the upper limit of the actual injection flow rate, that is, the actual injection volume may not reach the set value, but it can limit the further increase of the flow rate and play a protective role. 4. Injection pressure: refers to the pressure required per unit area when the contrast agent reaches the blood vessel at a certain flow rate. The injection pressure set at each time is the upper limit, which can play a certain protective role, usually expressed in PSI (pounds per square inch).

quality assurance system

DSA system is a large precision instrument, and its maintenance, use and management will directly affect the inspection results and treatment effects. (1) Factors affecting the quality of DSA images In the process of use, problems in every link can affect the images. 1. Line part: including the capacity of the machine, the selection of photographic conditions, the selection of focus, the size of exposure, etc. 2. Mechanical part: the cooperation between the catheter bed and the bulb tube in the process of image acquisition. 3. The performance of the high-pressure injector and its matching with radiography. 4. Image acquisition speed: the degree of signal loss in digital conversion. 5. Image acquisition quality: including the performance of image intensifiers and TV cameras, image storage devices (such as disks, tapes, video recorders) and multiple cameras, laser cameras, or dry printers. 6. Post-processing performance: such as mask reconstruction and pixel shift. 7. Selection of inspection method: such as digital film or digital subtraction. 8. The patient's cooperation during radiography: such as asking the patient to hold his breath. 9. Medical personnel's operation: such as the choice of catheter, whether the catheter is inserted into the target organ, etc. (II) Management of large-scale instruments and equipment Only by establishing strict rules and regulations can the safe operation of the equipment be guaranteed. 1. The equipment shall be tested and maintained by the maintenance company on a regular basis every year. 2. The environment of the computer room should be kept at 2 ~ 25% and the relative humidity at 4% ~ 7% all the year round, and it should be dehumidified in the rainy season in the south to keep the room dry. 3. The equipment, especially the image intensifier and high-pressure injector, shall be cleaned and maintained by the staff regularly every month. 4. The computer room and equipment should be disinfected by ultraviolet rays every day to prevent infection. 5. Check whether the equipment is in the best running state when starting. 6. Operate in strict accordance with the equipment operation procedures. (3) Protection of X-ray radiation in DSA inspection With the progress of society and the enhancement of environmental awareness, people pay more and more attention to X-ray radiation protection. Therefore, in DSA inspection, X-ray radiation should be controlled within a minimum range to prevent accidents. 1. X-ray monitoring inside and outside the computer room is carried out by the environmental monitoring station on a regular basis, and dose monitoring is carried out for medical personnel. 2. Medical personnel should strictly wear protective clothing. 3. Corresponding protective equipment shall be installed in the machine room. 4. Try to shorten the exposure time, narrow the exposure range and reduce the exposure times during inspection.