1, the history of the development of imaging navigation system
Image navigation technology (imaging navigator, imaging guide), also known as frameless stereotactic surgery (Flameless stereotaxy) or computer-assisted surgery (computer-assisted technology, computer-aided surgery, CAS), is in the framework of stereotactic technology The first hospital of Guangzhou Medical University Zhang Xiaowen, Department of Otolaryngology, Head and Neck, The First Hospital of Guangzhou Medical University
Stereotactic surgery, also known as framed navigation surgery, uses a framed stereotactic instrument, which is a metal bracket that can be fixed to the skull with a scale, and the position of the intracranial target can be determined by X-ray, CT or MRI and expressed by coordinate readings. Spiegel and Wycis invented the human stereotactic apparatus and used ventriculography to locate and destroy deep brain structures for the treatment of psychiatric disorders. In the early 20th century, x-ray radiographs were used to diagnose sinus disease, and in 1912 Mosher accurately inserted a probe into the frontal sinus with the aid of lateral x-ray radiography. In 1914, Cushing presented his experience with the use of radiography to localize the pterygoid sinus and saddle in pituitary tumor surgery. Early frame-guided surgery was not only inaccurate but also quite invasive due to poor imaging and radiographic techniques, which affected its clinical application. After the 1960s and 1970s, the accuracy and safety of frame-guided surgery were greatly improved by the widespread use of CT and MRI. However, frame-guided surgical devices have the following disadvantages that are difficult to overcome: ① positioning and guidance devices are bulky and lack flexibility; ② frame-guided devices cause patient discomfort; ③ positioning and guidance are not real-time, non-intuitive and cumbersome calculation methods; ④ not suitable for children or thin skull; ⑤ because the positioning frame affects the tracheal intubation, for those who need general anesthesia, they must first be intubated and then wear the positioning frame, which will increase anesthesia and surgery This will increase the time of anesthesia and surgery, and functional MRI examination cannot be performed. Due to its limitations, framed navigation surgery is currently used mainly for functional neurosurgery or directional tissue biopsy.
The rapid development of computer technology in the early 70’s has led to the use of computerized body scans to visualize the anatomy of the body, which led to Image Guide Surgery (IGS); with the use of magnetic resonance imaging, this has provided a clearer picture of the anatomy. However, these only provided two-dimensional images, and in specific surgeries the surgeon could only imagine the complex three-dimensional anatomy and consider the surgical route accordingly. With the rapid development of computers, radio and signal science and other related disciplines, image-guided surgical techniques were improved to form a truly interactive surgical planning and navigation tool, leading to the creation of computer navigation systems, a more accurate, flexible, convenient, and widely used intelligent frameless stereotactic technique that provides the three-dimensional (3D) interactive images required for surgery.
In 1986, Roberts in the United States was the first to report the use of acoustic digitizers to track surgical instruments or microscopes, bringing computerized navigation to clinical use and thus pioneering frameless stereotactic neurosurgery (Neuronavigator). In 1986, researchers at Aachen University Hospital in Germany were the first to investigate the use of image navigation systems in otolaryngology-head and neck surgery and developed the first generation of robotic arm type navigation systems, but the arm movement was limited and bulky and could not be adapted to the accuracy of otolaryngology surgery. In 1991, Kato reported on the design and clinical application of an electromagnetic digitizer, which consisted of a three-dimensional electromagnetic digitizer and a three-dimensional light-emitting diode (LED). In 1992, the infrared digitizer was used in clinical practice and is the most widely used surgical navigation system today. Based on the clinical application, Roth et al. proposed that the otorhinolaryngology image navigation system should have the following conditions: ① navigation and positioning accuracy within 2-3 mm; ② optional positioning methods to avoid repeated CT scans; ③ the patient’s head should be able to move whether under general anesthesia or local anesthesia; ④ the sensor is connected to surgical instruments such as suction, cutter, etc., and the connected surgical instruments are good operability ; ⑤ the navigation system can be manipulated directly by the physician without a technician. After more than twenty years of development, modern navigation technology better meets these conditions, intraoperative real-time navigation system is being applied and perfected stage.
2.System and principle
From the first generation of navigation systems to the present, nearly 20 years, although a variety of models of navigation systems have been introduced, but their composition and working principle is more or less the same. The navigation system is composed of a computer image processing system, signal receiving conduction system, signal source and other parts (Figure 1), the signal received by the signal receiver can be processed by the computer workstation, the signal source can be superimposed on the corresponding image, the image on the workstation screen presents the current anatomical site (to establish a corresponding relationship between the navigation sequence image and the patient’s brain structure). These three parts are connected by coaxial cable to become a whole, both by receiving infrared signals to sense the orientation of the patient’s head and microscope and various changes in movement, rotation, etc., but also in the workstation to issue instructions to command the robot arm to complete a variety of intraoperative auxiliary operations.
1, workstation (Workstation): due to the need to process and display a large amount of image information and data, neuronavigation system requires workstation general memory memory > 512 megabytes (M bytes), hard disk space is large enough, fast operation speed, with high resolution monitoring screen.
2, positioning devices (Localizating Devices): including positioning tools and three-dimensional digital converters. The navigation system can track the display of the positioning probe or tool held by the surgeon, that is, the position of the probe tip and the arc trajectory can be determined at any time. Although there are various positioning devices, they must be able to provide continuous, real-time positioning messages, with an update rate of not less than 30 times/second in the case of a conventional image picture of 3 mm thickness, and the accuracy in 67% of measurements should reach 0, 25 mm, and <1 mm in 95% of measurements.
(1) articulated arm positioning device: with 6 to 7 joints with position awareness, so that the position and angle of the probe can do 6 kinds of free movement, and can determine its spatial position. Here, the angular position of each joint is calculated by computer through the application of trigonometry, so as to calculate the position and angle of the probe tip. The ideal articulated arm positioning device should be well balanced, lightweight, free to move in any direction, securely fixed to the head frame and not interfere with the surgical operation.
(2) Active infrared positioning device: including positioning tools (such as probes, standard surgical instruments such as bipolar forceps, etc.), diodes emitting infrared light, and infrared receivers. The infrared rays emitted by the LED mounted on the positioning tool can be detected by two to three receivers in a row, so the position of the probe in space can be determined by the computer. As the LED detection device is small and compact, it can be mounted on standard surgical instruments, which is not only lighter and more flexible than the articulating arm, but also makes the surgical instruments multifunctional. In addition, the LED can be mounted on the reference head frame, and the reference head frame is fixed on the head frame, which can detect the movement of the head frame during surgery and give timely correction. Disadvantages: ① There must not be an obstacle between the LED device and the receiver, which may be difficult to do for busy and small operating rooms. When using the operating microscope, the infrared rays emitted by the surgeon’s handheld probe are easily blocked by the operating microscope. ②The infrared rays from the LED need to be at a certain angle to be received, so not only is the surgeon required to hold the probe without blocking the infrared rays, but also the positioning tool must be limited to a certain angle. (3) If the LED is partially blocked or malfunctioning, only 2 to 3 LEDs will be received and the positioning system will not be able to measure all directions of the positioning tool.
(3) Passive infrared positioning device: The basic principle and method are the same as the active infrared positioning device, except that the positioning tool is installed with several small balls that can reflect infrared rays, and the infrared transmitter and receiver are installed near the operation field. Since the reflective sphere is small and light, it can be mounted on any surgical instrument, and it does not need to be connected to a wire, so it is more flexible and convenient than the active infrared positioning device in use. Disadvantages: Same as active infrared positioning device.
(4) ultrasonic positioning device: detection and positioning with ultrasound. Advantages with infrared devices, and inexpensive, disadvantages also with infrared devices, but more susceptible to interference by various factors, such as temperature changes, airflow, echoes of walls and floors, obstacles, etc., and it requires a long probe, large receiver, the latter must be lined up within 1 meter of the operating field. Due to the inconvenient use, it is now used sparingly.
(5) surgical microscope positioning device: the above positioning devices such as LED, ultrasonic device and joint arm feeler are installed on the surgical microscope, plus laser measurement of the length of the lens focal point to determine the position of the surgical microscope, so that the focal center of the surgical microscope is like the probe tip of the handheld positioning device, which can display the orientation and dynamic tracking on the monitoring screen of the computer. In addition to the positioning and navigation functions, the corresponding CT and MRI images of the operating field seen by the operating microscope can be overlaid on the lens as needed, so that the surgeon does not have to interrupt the operation in order to see the CT and MRI images on the workstation monitoring screen. Disadvantages: ①It is not as convenient as handheld positioning device in applying surgical access design (skin incision, craniotomy, etc.), etc. ②The accuracy of positioning is poorer than that of the handheld positioning device. (3) The scope of the revealed surgical field is limited.
(6) Other positioning techniques: such as electromagnetic, inertial navigation, laser or radar scanning, television, etc. The reliability, accuracy and practicality of the application are yet to be determined.
3. Coordinates (Fiducials): They are a class of markers that can be seen both from the patient and on the imaging data and are used to link the two together. There are three kinds of coordinates: fixed coordinates, skin coordinates and anatomical coordinates, which should be selected according to the requirements of accuracy, cost and benefit of surgery. For example, the skin coordinates are a plastic product (sponge containing magnesium chloride) that can be applied to the skin. The advantages are ease of use, non-invasiveness, and economy. The disadvantage is that there is a certain error in positioning because of the mobility of the skin. Therefore, it is mainly used for procedures that do not require high accuracy. Anatomical coordinates are intrinsic markers of the head such as external auditory canal, para-auricular screen, nasal root, and extra-ocular contiguity, with the same advantages and disadvantages as skin coordinates. Fixed coordinates are also a plastic product that can be fixed on the skull or under the upper jaw (the latter is called maxillary buttress coordinates, which are acrylic products), without the disadvantage that the skin coordinates can move, but the patient has discomfort. Generally used for surgery with high positioning requirements, the maxillary rest is used for skull base surgery.
4, the scanner connection (Connected with Imaging Scanners): neuronavigation system workstation in addition to receiving image data through the scanner or CD-ROM, but also through the connector and CT and MRI scanners connected, so that the workstation to obtain more convenient image data, the amount of more.
5, Software Functions (Software Functions): Each navigation system has its own unique software, but their basic functions are similar. When the image data is input into the computer, the software can store the original location and level of the image, and through the reconstruction process to produce new, various orientation of the image data, as needed on the monitor screen. The 3D image reconstruction forms a computer model of the patient’s anatomy, which is useful not only for intraoperative navigation, but also for preoperative surgical planning and intraoperative registration. In particular, registration procedures can be simplified. When registration is complete and the probe tip is moved over the patient’s head, the approach of the probe tip to the corresponding CT and MRI images can be displayed on the monitor screen simultaneously and continuously. The neurovascular structures encountered by the surgical approach can be displayed as needed, i.e., projection viewing (trajection). This feature can also be used for surgical teaching and demonstration purposes. The 3D image display can be rotated as required, with the surface structures becoming transparent to show the structures of interest within them. The image can be still or continuously moving and a ruler is available to accurately measure the distance between any two points. Image quality is clear and fidelity is dependent on the performance of the workstation in addition to the quality of the original CT and MRI images.
The InstaTrak system uses an electromagnetic wave system where metal instruments can interfere with signal transmission, and the monitor automatically alerts the operator when interference occurs. Two layers of mattress pads are required between the patient and the metal table, and a certain distance between the instrument table, anesthesia machine, and other metal instruments and the surgical area. The CT system requires the patient to wear the same head frame before and during surgery, and care should be taken to prevent the head frame from being distorted by hair clips, hair bands, etc. The CT thickness is 3 mm, and the scanning range is from the base of the mandible to 2 or 5 mm above the metal ball of the head frame, which must be worn by the patient on the day of surgery. The Insta Trak system is capable of automatic registration: the markers are pre-embedded in the head frame, so there is no need for body markers to calibrate the anatomy. Because the instaTrak system uses an electromagnetic wave system, metal instruments can interfere with signal transmission, and the monitor automatically alerts the operator when interference occurs. Instatrack uses a non-metallic suction tip, which has the advantage of targeting rapid bleeding, but has difficulty reaching the frontal sinus with a curved suction tip due to its caliber and tip structure.
The Stealthstation system uses an infrared tracking system to show the position of the surgical instruments in the patient’s preoperative CT in a timely manner. The ends of the instruments are reflected on the coronal, sagittal, and transverse CT in a criss-cross pattern, and the photoreceptors are three infrared receptors arranged on a fixed device located 6 feet in front of the operating table. The receptors track the position of infrared emission points placed on standard surgical instruments or direct suction devices, and a series of infrared emission points on the patient’s head frame are used to monitor head movement. The Station system uses standard endoscopic surgical instruments with infrared emission points for positioning and has the advantage of being able to operate in the frontal saphenous area with a small, curved tip suction that allows access to the frontal sinus and shows different positions within a large sinus cavity. stealth station-landmarX otolaryngology-head and neck surgery imaging Navigation system Adopts the principle of optical positioning without electromagnetic interference and deflection; has a powerful image data processing system and room for upgrades; small machine workstation with processing speed approximately 20 times faster than microcomputer-based navigation systems, etc. The graphic form depicts navigation accuracy in areas of less than 1 mm, providing more information than a single digital display. Interoperable with Medtronic’s Steath Station navigation system. It can be adapted to most hard instruments, power cutting drills, frontal sinus drilling instruments, etc.; the software can support all otorhinolaryngology procedures; it can be wired or wirelessly used with a variety of otorhinolaryngology-specific instruments.
3.Application of image navigation system
The image navigation system is in principle applicable to all nasal endoscopic surgeries, as well as some otology and skull base surgeries.3,1 Complex sinusitis and nasal polyps. In patients who have undergone sinusitis surgery, important anatomical landmarks such as middle turbinates, hooks, substrate and sieve funnel have been removed, and if recurrence requires reoperation, it will be more difficult for physicians; in patients with chronic sinusitis with obvious mucosal hypertrophy, some bleed more during surgery, which increases the difficulty of surgery; some patients with sinusitis have abnormal local anatomical structures, such as: infraorbital septum, superior pterygoid septum, abnormal course of internal carotid artery, Some patients with sinusitis have local anatomical abnormalities, such as: suborbital septum, suprasphenoidal septum, abnormal internal carotid artery, abnormal development of nasal frontal canal, abnormal development of pterygoid sinus, etc., which may cause incomplete sinus opening and incomplete lesion removal. If the navigation system is used during the operation, the above difficulties can be easily overcome. Roth et al. used the Viewing Wand system to perform sinus surgery on patients with nasal cavity and sinus tumors, including osteochondral dysplasia and osteoma, and the results were very helpful for patients with disrupted local anatomy. In 2000, the Department of Otolaryngology, Head and Neck Surgery of Beijing Tongren Hospital performed 6 cases of transnasal endoscopic nasopharyngeal fibrovascular tumor resection with the aid of navigation system, which reduced the risk of surgery to a certain extent and could accurately determine the boundaries of the tumor, especially for recurrent nasopharyngeal fibrovascular tumors. The CT showed complete resection of the tumor 1 year after surgery. 3,3 Optic nerve decompression. 3.4 Transsphenoidal sinus biopsy or drainage. 3,5 Transsphenoidal sinus pituitary mass resection. moses et al. performed pituitary tumor resection under Insta trak system navigation. the disease included 5 cases of pituitary adenoma and 1 case of craniopharyngioma. the navigation system cooperated well with the endoscope, and the tumor was completely resected intraoperatively with no intraoperative and postoperative complications. Eight cases of pituitary adenoma resection by transnasal endoscopy with the assistance of navigation system were performed in the Department of Otolaryngology-Head and Neck Surgery of Beijing Tongren Hospital, which increased the operator’s certainty and confidence in accurate and complete tumor removal without intraoperative and postoperative complications. However, it is worth noting that in performing resection of huge pituitary tumor, when the lower part of the tumor is removed partially, the position shown by the navigation guide is much different from the actual one, and the upper part of the tumor hangs down, which is completely different from the one shown by the original image, at this time, it is not possible to rely on the navigation to help positioning. 3,6 Biopsy or surgical resection of the skull base. Klimek et al. performed 14 skull base surgeries in children under the navigation of a robotic arm-type navigation system and concluded that the use of navigation systems in endoscopic surgery of the anterior skull base is helpful in improving surgical safety. Carney et al. performed 14 surgeries of the skull base, sinus cerebral horn, and skull using the Viewing Wand system and concluded that the system is useful for extensive resection under minimally invasive approaches. The system was found to be useful for the wide range of lesion removal under minimally invasive approach.
4. The advantages of using an image navigation system in sinus surgery
Intraoperative application of the navigation system has the following advantages: (1) accurately determine the three-dimensional spatial location of the operation (answer: where is it now?) (2) Showing the structures adjacent to the operative field (answer: what is around?) . (3) Indicate the orientation of the target site and its spatial relationship to the intended surgical site (answer: in what direction should you proceed?). . (4) Help design the ideal surgical approach (answer: how should the target be reached?). . (5) Show the structures that may be encountered along the surgical approach (Answer: What is along the path?). . (6) Show the location of important structures (Answer: what is being avoided?) . . (7) Show the size and extent of the target space (Answer: How much of the lesion is removed?) . .
Surgery with image navigation technology has the irreplaceable advantages of functional sinus surgery: i. Precise positioning: the accuracy is only 1,0 to 1,5 mm (core), which is impossible for the human eye to achieve at the magnification of nasal endoscopy. Second, provide important information (location in three-dimensional space, adjacent important structures, spatial relationship between the lesion site and the surgical site and important structures that may be encountered).
The main advantage of applying image navigation system in sinus surgery is to provide anatomical positioning to the operator at any time during surgery and to enhance the operator’s self-confidence. Theoretically, the image navigation system helps to reduce surgical complications. In the following cases, the image navigation system can help to identify the anatomical landmarks destroyed by new organisms and determine the extent of the tumor, which can help to remove the tumor completely and prevent damage to normal tissues. The image navigation system can help the operator to determine the anatomical structure correctly. In addition, the image navigation system can also help in teaching, potentially providing safety assurance for difficult surgery and saving operation time.
5. Shortcomings and potential risks of using image navigation system in sinus surgery
The disadvantages of using the image navigation system are mainly in the following aspects: ① The need to wear a special positioning device for CT or MRI scanning before surgery, which is a cumbersome procedure and increases the cost of surgery for patients; ② According to the literature, when the image navigation system is initially applied, the pre-surgical preparation time (including alignment, head frame positioning, instrument registration, etc.) for each/every patient can extend the total surgical time by 15-30 min, even after mastering the image navigation system. (3) The existing image navigation system is based on the CT or MRI images before surgery, which cannot reflect the changes during surgery in real time, for example, the resection of the lesion (tumor) cannot be displayed in real time during surgery, but only based on the 3D images constructed before surgery. To solve this problem, real-time intraoperative image navigation systems have been developed abroad, such as the intraoperative MRI navigation system introduced by Medtronic, which may be able to make up for the shortcomings of the image navigation system to a certain extent; ④ The accuracy of the image navigation system is better in bony or rigid frames, but in soft tissues, or in cases where the anatomical structure changes with the surgical operation, the accuracy of the image navigation system is based on the preoperative parameters. In the case of soft tissue operations, or when the anatomy changes with the surgical operation, navigation based on the preoperative parameters is prone to deviations in indication. For example, when a large pituitary tumor is resected, the pituitary gland moves toward the base of the pterygoid saddle or the cavernous sinus moves toward the midline under intracranial pressure, resulting in a change in anatomical position, which may cause surgical errors if the information provided by the image navigation system is believed. The cost of image navigation system is too high, which is not conducive to the popularization of the system in hospitals and increases the financial burden of patients. In 2003, Metson performed a retrospective analysis of 1000 nasal endoscopic procedures with an image-guided system, and three of them resulted in nasal leakage of cerebrospinal fluid. There are two main reasons for complications with the use of image navigation systems: ① The computer-displayed three-dimensional images are reconstructed from preoperative horizontal CT, which inevitably results in a certain degree of error in the reconstruction process and may cause even greater deviations due to the movement of the head frame during the procedure. It has been reported in the literature that in routine clinical applications, the ability of the image navigation system to locate anatomical structures is within 2 mm, and if it exceeds a certain value, i.e., if the positioning accuracy decreases to more than 2 mm, surgical errors are likely to occur. Therefore, the image guidance system is only relatively accurate and reliable. ② For inexperienced surgeons, if they believe too much in the image navigation system and think that with the image navigation system as a “license”, they can operate in the sinus with confidence and boldness, it is more likely to have complications.
6, the application of image navigation system indications
Although some scholars recommend the use of image navigation systems for all patients undergoing endoscopic sinus surgery, this view is still controversial. In 1994, Anon et al. suggested that the strongest indications for the use of imaging navigation systems include: ① revision surgery; ② extensive lesions; ③ pterygoid sinus lesions; ④ Onodi airspace or other anatomical variants with potential surgical complications; ⑤ frontal saphenous-frontal sinus lesions; ⑥ optic nerve hypoplasia lesions; ⑥optic nerve decompression surgery; ⑦nasal cavity-sinus malignant tumor surgery.
7.How to use
The application of computerized navigation system includes three parts: 1) acquisition and input of imaging data; 2) preoperative planning; 3) intraoperative positioning and planning implementation. In this paper, we use Medtronic’s Stealth Station LandmarX navigation system as an example to briefly explain.
1.Preoperative preparation: 7-lO reference markers (Fiducial) are placed in the patient’s head 1 day before surgery (2 days in a few patients) and a spiral CT or MR scan of the sinuses is performed. CT scan parameters: continuous scan in horizontal position, layer thickness 1 mm, soft tissue window, FOV >200 mm, approximately 90-110 levels. The scan covers the frontal sinuses superiorly, inferiorly to the lower edge of the earlobe, and anteriorly to the tip of the nose. The obtained data were saved on magnetic disc (MO) and input into the navigation system, and the preoperative navigation plan was performed, including the overall 3D reconstruction of the image (Figure 2), the calibration, the design of the surgical approach (Figure 3) and the lesion area (Figure 4).
2. Intraoperative preparation: Before or during anesthesia, the LandmarX software is activated to display the reconstructed 3D image data of the patient, and the head is fixed after general anesthesia and aligned according to the sequence of sites selected on the 3D model before surgery. After successful alignment, the intraoperative positioning device is registered. After registration, the operator can use probes, suction devices and other positioning devices according to the intraoperative need to judge the progress of surgery (Figure 5), the adjacent anatomical relationship, the extent of lesion removal, etc.
8. Precautions for applying the image navigation system
It should be clear that the application of image navigation system in sinus endoscopic surgery is only relatively accurate and reliable, however, it is not perfect and has certain limitations. In addition, from another perspective, the surgical image navigation system is a potentially dangerous technique that may provide a false sense of security to the operator if not properly recognized and used. In order to better play the auxiliary role of the image navigation system we would like to make the following recommendations: 1, modern image navigation technology cannot replace the learning of anatomical knowledge and surgical training, the accumulation of surgical experience is the first important. When starting to apply the image navigation system, it is best to choose relatively simple cases, so that even without the aid of the image navigation system, or when the image navigation system does not work well, the surgeon can complete the surgery with ease. During the surgery, the accuracy of the image navigation system should be verified at all times. The operator can check the accuracy of the anatomical site shown by the image navigation system according to the known anatomical landmarks in the surgical field. Once deviations are found, they should be aligned immediately. It should be noted that sometimes the accuracy of the image navigation system is different in different anatomical sites, for example, in the anterior septal sinus group is very accurate, while in the anterior wall of the pterygoid sinus there is a significant error. When using an image navigation system to perform sinus surgery, trust your surgical experience if the information provided by the image navigation system conflicts with the operator’s experience. For example, when the surgeon places the probe at the top of the sieve, the crosshairs indicate that the crosshairs are inside the skull, which can be judged as an error of the image navigation system. If the probe is already out of position (into the skull) and the crosshairs are still in a safe place, serious complications may occur if the image navigation system is trusted too much. It is believed that the use of image navigation systems in sinus surgery will become more and more widespread in the future, therefore, both physicians who are using image navigation systems and those who are preparing to learn to use them should clearly understand the advantages and potential risks of image navigation systems as an aid, and more importantly, rely on people, not on equipment. Only in this way can we promote and facilitate the improvement and development of image navigation systems.
9, the development trend of image navigation technology
1, the computer and software aspects of navigation systems: ① With the development and application of fast processing systems, computer-based applications will reach previously unimaginable levels. Computer performance is likely to replace the current application of workstations, so that the navigation system is not only greatly reduced in size or portability, the price can also be reduced. ②The development of high-resolution stereoscopic monitor screen will be conducive to the display of complex structures in the deep brain. ③ Hard and software development makes the application of navigation system easier, and the equipment is highly automated and
Intelligent, can automatically register and correct deviation. ④A variety of images (CT, MRI, fMRI, DTI, MRA, PET, CTA, MEG, etc.) automatically fuse to provide surgeons with more options and information, making navigation surgery safer and more effective.
2. Virtual Reality (VR) technology. Using fusion and navigation technology, the patient’s MRI, MRA, MRV and CT imaging data are fused in the neuro-navigation system before surgery. Navigation involves creating a computer model of the molecule and for the user to be able to move around. Just as in this model. The images can be perceived visually and transmitted electronically. The surgeon can perform a realistic simulation prior to surgery, walking into a visual virtual tumor environment to view the tumor from multiple sides, avoiding the disadvantages of viewing from one side or not actually entering the tumor. It is found that VIVIAN can provide the following functions: 1. Realistic three-dimensional spatial relationship between the diseased tissue and the surrounding normal anatomical structures; 2. Simulation of surgical operations of craniotomy and bony structures of the skull base; 3. Simulation of intraoperative imaging. Conclusion: Through the VIVIAN system, the surgeon can make full use of the imaging data to understand the spatial relationship between the diseased tissue and the normal structures to the greatest extent, which helps to select the correct surgical approach.
3. Intraoperative real-time scanning image navigation (iMRI). In the process of applying neurological navigation, the accuracy of the registration point is a key factor in determining the success of navigation. The preoperative image data does not reflect the changes during surgery in real time, and in the case of soft tissue manipulation or anatomical structure changes with the surgical operation, the indication deviation may easily occur. Intraoperative navigation (iMRI) is currently considered to be the best solution to this problem, but it is not yet widely available due to its high cost and the increased risk of postoperative infection due to the prolonged operating time and the possibility of contamination of the surgical sterile area. Many studies have shown that there is no significant difference in the accuracy of intraoperative 3D ultrasound images compared with CT and MRI images, which can also provide sufficient navigation information.
4, functional image navigation surgery. Such as the combination with endoscopy to complete the intracerebroventricular or deep brain lesion micro-invasive surgery, the development of functional brain data input, and the combination of magnetoencephalography technology to make the localization functional; and cerebrovascular imaging can be combined with the localization of very small vessels, for cerebrovascular disease treatment navigation.
5, robot and remote control surgery (telesurgery): recently there has been the application of robots or robotic arms to manipulate the operating microscope, grinding drill, retractor, electrodes, endoscopy, etc.. Will not occur manual tremor or shaking and other shortcomings. In the near future, robots under human control to perform some surgical procedures, that is, remote surgery, may become a reality.
The connotation of modern nasal endoscopic surgery is: under the direct vision of the nasal endoscope, remove the lesion, improve and reconstruct the function of nasal cavity and sinus ventilation and drainage, and preserve the normal anatomical structure and function of nasal cavity and sinus as far as possible, so as to achieve the purpose of curing sinusitis nasal surgery technology. If nasal endoscopy provides clear illumination, there is no doubt: navigation and positioning technology provides precise positioning. The combination of navigation technology and nasal endoscopy is the refinement and development of modern minimally invasive nasal surgery. But it is more important to rely on people, not only on equipment.