Navigation System For Surgery Research Articles

Accuracy and efficiency of dynamic navigated root-end resection in endodontic surgery: a pilot in vitro study.

The operation accuracy and efficiency of dynamic navigated endodontic surgery were evaluated through in vitro experiments. This study provides a reference for future clinical application of dynamic navigation systems in endodontic surgery. 3D-printed maxillary anterior teeth were used in the preparation of models for endodontic surgery. Endodontic surgery was performed with and without dynamic navigation by an operator who was proficient in dynamic navigation technology but had no experience in endodontic surgery. Optical scanning data were applied to evaluate the length and angle deviations of root-end resection. And the operation time was recorded. T tests were used to analyze the effect of dynamic navigation technology on the accuracy and duration of endodontic surgery. With dynamic navigation, the root-end resection length deviation was 0.46 ± 0.06mm, the angle deviation was 2.45 ± 0.96°, and the operation time was 187 ± 22.97s. Without dynamic navigation, the root-end resection length deviation was 1.20 ± 0.92mm, the angle deviation was 16.20 ± 9.59°, and the operation time was 247 ± 61.47s. Less deviation was achieved and less operation time was spent with than without dynamic navigation (P < 0.01). The application of a dynamic navigation system in endodontic surgery can improve the accuracy and efficiency significantly for operators without surgical experience and reduce the operation time.

Feasibility and Usability of Augmented Reality Technology in the Orthopaedic Operating Room.

Augmented reality (AR)has gained popularity in various sectors,including gaming, entertainment, and healthcare. The desire for improved surgical navigation within orthopaedic surgery has led to the evaluation of the feasibility and usability of AR in the operating room (OR). However, the safe and effective use of ARtechnologyin the OR necessitates a proper understanding of its capabilities and limitations. This review aims to describe the fundamental elements of AR, highlight limitations for use within the field of orthopaedic surgery, and discuss potential areas for development. To date, studies have demonstrated evidence that AR technology can be used to enhance navigation and performance in orthopaedic procedures. General hardware and software limitations of the technology include the registration process, ergonomics, and battery life. Other limitations are related to the human response factors such as inattentional blindness,which may lead to the inability to see complications within the surgical field. Furthermore, the prolonged use of AR can causeeye strain and headache due to phenomena such as thevergence-convergence conflict. AR technology may prove to be abetter alternative to current orthopaedic surgery navigation systems. However, the current limitations should be mitigated to further improve the feasibility and usability of AR in the OR setting. It is important for both non-clinicians and clinicians to work in conjunction to guide the development of future iterations of AR technology and its implementation into the OR workflow.

A Novel Intraoperative CT Navigation System for Spinal Fusion Surgery in Lumbar Degenerative Disease: Accuracy and Safety of Pedicle Screw Placement.

Background: In recent years, intraoperative computed tomography (CT) navigation has become widely used for the insertion of pedicle screws in spinal fusion surgery. However, conventional intraoperative CT navigation may be impaired by infrared interference between the infrared camera and surgical instruments, which can lead to the misplacement of pedicle screws. Recently, a novel intraoperative CT navigation system, NextAR, has been developed. It uses a small infrared camera mounted on surgical instruments within the surgical field. NextAR navigation can minimize the problem of infrared interference and be expected to improve the accuracy of pedicle screw placement. Methods: This study investigated the accuracy of pedicle screw insertion under NextAR navigation in spinal fusion surgery for lumbar degenerative diseases. The accuracy of pedicle screw placement was evaluated in 15 consecutive patients using a CT grading scale. Results: Screw perforation occurred in only 1 of the total 70 screws (1.4%). Specifically, there was one grade 1 perforation within 2 mm, but no perforations larger than 2 mm. There were no reoperations or neurological complications due to screw misplacement. Conclusions: NextAR navigation can provide high accuracy for pedicle screw insertion and help ensure safe spinal fusion surgery for lumbar degenerative diseases.

A Novel Lightweight Navigation System for Oral and Maxillofacial Surgery Using an External Curved Self-Identifying Checkerboard

This paper presents a novel lightweight navigation system for oral and maxillofacial surgery (OMS). An external curved checkerboard with self-identifying markers is set as the reference object around the surgical scene. A customized oral clip with a micro camera is designed for oral localization by tracking the external checkerboard. Similarly, the dental handpiece is also equipped with a micro camera, which can be localized like the clip. The spatial model of the markers is provided by binocular stereoscopic reconstruction. A front surface mirror is taken up for the registration between the oral cavity and the camera on the clip. The pivot calibration of the dental handpiece is accomplished by our proposed calibration method. We set up an experimental group and a control group for evaluation. The surgical tools of the experimental group were approximately 30% lighter, 35% less bulky, and 90% cheaper than those of the control group. Our system yielded the comprehensive navigation accuracy of 0.92 mm whereas the accuracy of the control group was 0.87 mm. Results revealed that our system can achieve similar accuracy compared with a prevailing system at a lighter weight, a more compact volume, and a lower cost. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —The motivation of this work is to reduce the burden on patients and surgeons during OMS. Current commercial navigation systems are still limited by the burden of extra cumbersome fiducial markers and high hardware costs. Their high accuracy benefits from the large size of fiducial markers. To take full advantage of the camera’s localization effect, we propose the concept of “marker-camera inverse projection”, i.e., reversing the roles of the camera and the markers. In this way, cameras on surgical tools detect more points with a more uniform distribution. Our proposed system achieves a decent balance between navigation accuracy and hardware cost, which facilitates the development of surgical tools to be lighter and more economical, and involves tremendous potential for commercialization.

Surgical Navigation in the Anterior Skull Base Using 3-Dimensional Endoscopy and Surface Reconstruction

Image guidance is an important adjunct for endoscopic sinus and skull base surgery. However, current systems require bulky external tracking equipment, and their use can interrupt efficient surgical workflow. To evaluate a trackerless surgical navigation system using 3-dimensional (3D) endoscopy and simultaneous localization and mapping (SLAM) algorithms in the anterior skull base. This interventional deceased donor cohort study and retrospective clinical case study was conducted at a tertiary academic medical center with human deceased donor specimens and a patient with anterior skull base pathology. Participants underwent endoscopic endonasal transsphenoidal dissection and surface model reconstruction from stereoscopic video with registration to volumetric models segmented from computed tomography (CT) and magnetic resonance imaging. To assess the fidelity of surface model reconstruction and accuracy of surgical navigation and surface-CT model coregistration, 3 metrics were calculated: reconstruction error, registration error, and localization error. In deceased donor models (n = 9), high-fidelity surface models of the posterior wall of the sphenoid sinus were reconstructed from stereoscopic video and coregistered to corresponding volumetric CT models. The mean (SD; range) reconstruction, registration, and localization errors were 0.60 (0.24; 0.36-0.93), 1.11 (0.49; 0.71-1.56) and 1.01 (0.17; 0.78-1.25) mm, respectively. In a clinical case study of a patient who underwent a 3D endoscopic endonasal transsphenoidal resection of a tubercular meningioma, a high-fidelity surface model of the posterior wall of the sphenoid was reconstructed from intraoperative stereoscopic video and coregistered to a volumetric preoperative fused CT magnetic resonance imaging model with a root-mean-square error of 1.38 mm. The results of this study suggest that SLAM algorithm-based endoscopic endonasal surgery navigation is a novel, accurate, and trackerless approach to surgical navigation that uses 3D endoscopy and SLAM-based algorithms in lieu of conventional optical or electromagnetic tracking. While multiple challenges remain before clinical readiness, a SLAM algorithm-based endoscopic endonasal surgery navigation system has the potential to improve surgical efficiency, economy of motion, and safety.

Current status and reflection on minimal access breast surgery

Minimal access breast surgery with the assistance of an endoscopy or robot has been an important advancement in surgical treatment in recent years. Compared to conventional open surgery, minimal access breast surgery only requires small incisions in concealed areas such as axillary fossa, avoiding visible scars on the surface of the breast, significantly improving the postoperative aesthetic appearance and patient satisfaction. With the rapid development of minimal access breast surgery, several institutions have established their own distinctive techniques. The concept of membrane anatomy in the breast, for example, has led to more natural-looking breast reconstruction following endoscopic procedures. The adoption of the reverse space dissection technique has greatly optimized the workflow of endoscopic breast cancer resection. Intraoperative navigation system for endoscopic breast-conserving surgery could allow precise localization of excision margins. Furthermore, the widespread use of the cold dissection technique for flap separation has reduced surgical duration and minimized flap damage. The emergence of unique techniques in the field of minimal access breast surgery promises to further advance and promote the adoption of minimal access breast surgery in China.

Clinical evaluation of augmented reality-based 3D navigation system for brachial plexus tumor surgery

BackgroundAugmented reality (AR), a form of 3D imaging technology, has been preliminarily applied in tumor surgery of the head and spine, both are rigid bodies. However, there is a lack of research evaluating the clinical value of AR in tumor surgery of the brachial plexus, a non-rigid body, where the anatomical position varies with patient posture.MethodsPrior to surgery in 8 patients diagnosed with brachial plexus tumors, conventional MRI scans were performed to obtain conventional 2D MRI images. The MRI data were then differentiated automatically and converted into AR-based 3D models. After point-to-point relocation and registration, the 3D models were projected onto the patient’s body using a head-mounted display for navigation. To evaluate the clinical value of AR-based 3D models compared to the conventional 2D MRI images, 2 senior hand surgeons completed questionnaires on the evaluation of anatomical structures (tumor, arteries, veins, nerves, bones, and muscles), ranging from 1 (strongly disagree) to 5 (strongly agree).ResultsSurgeons rated AR-based 3D models as superior to conventional MRI images for all anatomical structures, including tumors. Furthermore, AR-based 3D models were preferred for preoperative planning and intraoperative navigation, demonstrating their added value. The mean positional error between the 3D models and intraoperative findings was approximately 1 cm.ConclusionsThis study evaluated, for the first time, the clinical value of an AR-based 3D navigation system in preoperative planning and intraoperative navigation for brachial plexus tumor surgery. By providing more direct spatial visualization, compared with conventional 2D MRI images, this 3D navigation system significantly improved the clinical accuracy and safety of tumor surgery in non-rigid bodies.

A spatial registration method based on 2D-3D registration for an augmented reality spinal surgery navigation system.

In order to provide accurate and reliable image guidance for augmented reality (AR) spinal surgery navigation, a spatial registration method has been proposed. In the AR spinal surgery navigation system, grayscale-based 2D/3D registration technology has been used to register preoperative computed tomography images with intraoperative X-ray images to complete the spatial registration, and then the fusion of virtual image and real spine has been realised. In the image registration experiment, the success rate of spine model registration was 90%. In the spinal model verification experiment, the surface registration error of the spinal model ranged from 0.361 to 0.612mm, and the total average surface registration error was 0.501mm. The spatial registration method based on 2D/3D registration technology can be used in AR spinal surgery navigation systems and is highly accurate and minimally invasive.

The benefits of a hybrid operation room in neurosurgery.

The hybrid operation room - with a robotic arm equipped angiographic device - started its operation in November 2019 at the Department of Neurosurgery, Szeged, Hungary. We report the benefits of the hybrid operation room in the neurosurgery practice based on our results and experiences of the last 1.5 years. 576 operations took place between 15. 11. 2019 and 01. 03. 2021, which include 332 neurointerventions amd 244 skull-brain and spine surgeries. By using Siemens ARTIS pheno®, we performed purely catheter only interventions or surgical only interventions, but combined treatments were also performed in several cases (catheter and surgical intervention). Thanks to ARTIS pheno® versatility, it is used as a modern imaging system in preoperative examination or as navigation system in spine surgery and control imaging for intra- and postoperative examinations. We created three categories based on the results of the last months according to the need of using the hybrid operation room for the given operation: (1) strongly recommended, (2) recommended, (3) advantageous. Strongly recommended: if the two teams (surgical and interventional team) have to work together during the operation. Recommended: if the two teams are not participating together in the operation, but the other team is on standby and may join the operation if necessary. Advantageous: this category means the possibility of performing control imaging before the wound closure. Based on our experience, the hybrid operation room provides significant help in neurosurgery. It has become part of our daily care, and we think it is indispensable in the work of a neurosurgery center. Orv Hetil. 2023; 164(43): 1701-1711.

Poor usability of computer-assisted navigation for hip fracture surgery

IntroductionThe STRYKER ADAPT computer-assisted navigation system provides intraoperative feedback to the surgeon regarding implant placement of the Gamma3 nail. The usability of the ADAPT system has not been evaluated. The aim of the study was to investigate the perceived usability of the ADAPT system.Materials and methodsThis was a descriptive study with prospectively collected data. ADAPT was introduced at Aarhus University Hospital in February 2021. Prior to introduction, surgeons at the department attended a general introduction to the system. ADAPT was introduced to the surgical nurses and was on display at the surgical ward at more than one occasion, where personal introduction to the system was possible. After introduction, it was mandatory to use ADAPT when using the Gamma3 nail to treat intertrochanteric femur fractures. After each procedure, primary and an eventual supervisor answered a questionnaire, which encompassed the System Usability Scale (SUS) questionnaire. The SUS is a ten-item questionnaire regarding the perceived usability of a system. SUS scores were translated to adjectives, describing user experience on a 7-point adjective scale (worst imaginable, awful, poor, ok, good, excellent, best imaginable). User acceptability, defined as “not acceptable”, “marginal” or “acceptable”, was also used to interpret the SUS scores.ResultsADAPT was used in 50 procedures by 29 different surgeons, with varying skill-level. Median SUS-score after first-time use of ADAPT for all 29 surgeons was 43 (range: 5–60), which translated to “poor” or “not acceptable”. For surgeons who performed ≥ 3 ADAPT-assisted procedures, there were no statistically significant difference in their first to latest SUS-score (median difference: 4.3, p = 0.5). In free text comments ADAPT was positively described as helpful in placement of K-wire and providing educational opportunities for inexperienced surgeons and negatively as inconsistent, slow, time consuming, and causing excessive fluoroscopy.ConclusionsUsability and acceptability of ADAPT was rated as “poor” or “not acceptable” by the majority of operating surgeons. ADAPT has not been used at our institution based on these findings. The System Usability Scale may be used in further research exploring usability and acceptability of novel computer-assisted navigation systems for orthopaedic surgery.

Navigation system for oral surgery based on slam technology

As a combination of modern imaging technology, stereotactic technology, computer technology, and artificial intelligence technology, the surgical navigation system has been rapidly developed and applied in recent years. In recent decades, navigation systems have been used to aid in maxillofacial surgery, but rarely in the oral area. By comparing the applications of navigation systems in oral and maxillofacial surgery, we summarize their advantages and problems and list the advantages and disadvantages of the development process and methods of Simultaneous Localization and Mapping(SLAM). We propose to use tooth contours as natural markers to construct a model of AR oral structure, subtracting the operational time problems caused by making and using artificial markers. The AR structure model of the oral cavity was constructed, the method of applying SLAM technology to the oral surgery was proposed reasonably, and the method optimization scheme was proposed for the more complicated oral root canal surgery.

Application of an effective marker-less augmented reality image guidance method in dental implant surgery.

The existing augmented reality (AR) dental implant surgery navigation system usually uses markers to complete image guidance. However, markers often affect dentists' operations and make patients uncomfortable. To solve the problems caused by markers, this paper proposes an effective marker-less image guidance method. After initialisation is completed by contour matching, the corresponding relationship is obtained by matching the feature points between the current frame and the preloaded initial frame. The camera pose is estimated by solving the Perspective-n-Point problem. The registration error of AR images is 0.731±0.144mm. The planting errors are 1.174±0.241mm at the neck, 1.433±0.389mm at the apex and 5.566±2.102° for the angle. The maximum error and standard deviation meet the clinical requirements. We demonstrate that the proposed method can accurately guide dentists to perform dental implant surgery.

Multi-mode information fusion navigation system for robot-assisted vascular interventional surgery

BackgroundMinimally invasive vascular intervention (MIVI) is a powerful technique for the treatment of cardiovascular diseases, such as abdominal aortic aneurysm (AAA), thoracic aortic aneurysm (TAA) and aortic dissection (AD). Navigation of traditional MIVI surgery mainly relies only on 2D digital subtraction angiography (DSA) images, which is hard to observe the 3D morphology of blood vessels and position the interventional instruments. The multi-mode information fusion navigation system (MIFNS) proposed in this paper combines preoperative CT images and intraoperative DSA images together to increase the visualization information during operations.ResultsThe main functions of MIFNS were evaluated by real clinical data and a vascular model. The registration accuracy of preoperative CTA images and intraoperative DSA images were less than 1 mm. The positioning accuracy of surgical instruments was quantitatively assessed using a vascular model and was also less than 1 mm. Real clinical data used to assess the navigation results of MIFNS on AAA, TAA and AD.ConclusionsA comprehensive and effective navigation system was developed to facilitate the operation of surgeon during MIVI. The registration accuracy and positioning accuracy of the proposed navigation system were both less than 1 mm, which met the accuracy requirements of robot assisted MIVI.

Application of 3D printing navigation system in pediatric epiphyseal complex lesion surgery

To investigate 3D printing navigation system in pediatric epiphyseal complex lesion surgery. 10 children with epiphyseal complex lesions of the lower limb were recruited. After collecting imaging data such as CT and MRI in children with epiphyseal complex lesions of the lower limb, a three-dimensional model of bone was constructed using 3D printed computer modeling technologies for the localization of the lesion area. The extent of bone bridges was less than 30%, and all of them met the indications for bone bridge resection surgery. 3D printed navigation templates guided lesion resection. Epiphyseal block growth regulation with a figure-of-eight plate was also used in cases with preexisting abnormal alignment. During the operation, the average surgical incision was 4.0 cm, the bone bridge positioning was accurate, and the bone bridge tissue could be successfully and completely removed. As a result of follow-up, no cases had residual bone bridge tissue, no iatrogenic epiphyseal injury was found, and the epiphyseal plate was open in all children. 3D printing navigation system improved the accuracy of resection of lower limb epiphyseal complex lesions, significantly reduced the need for intraoperative fluoroscopy, avoided iatrogenic injury to the epiphyseal complex due to positioning errors, thereby reducing postoperative complications and considerably improving the prognosis of a series of lower limb epiphyseal complex lesion diseases in children.

Basic Experiments Toward Mixed Reality Dynamic Navigation for Laparoscopic Surgery

Laparoscopic surgery is a minimally invasive procedure that is performed by viewing endoscopic camera images. However, the limited field of view of endoscopic cameras makes laparoscopic surgery difficult. To provide more visual information during laparoscopic surgeries, augmented reality (AR) surgical navigation systems have been developed to visualize the positional relationship between the surgical field and organs based on preoperative medical images of a patient. However, since earlier studies used preoperative medical images, the navigation became inaccurate as the surgery progressed because the organs were displaced and deformed during surgery. To solve this problem, we propose a mixed reality (MR) surgery navigation system in which surgical instruments are tracked by a motion capture (Mocap) system; we also evaluated the contact between the instruments and organs and simulated and visualized the deformation of the organ caused by the contact. This paper describes a method for the numerical calculation of the deformation of a soft body. Then, the basic technology of MR and projection mapping is presented for MR surgical navigation. The accuracy of the simulated and visualized deformations is evaluated through basic experiments using a soft rectangular cuboid object.

A novel motionless calibration method for augmented reality surgery navigation system based on optical tracker

Augmented reality (AR) surgery navigation systems display the pre-operation planned virtual model at the accurate position in the real surgical scene to assist the operation. Accurate calibration of the mapping relationship between the virtual coordinate and the real world is the key to the virtual-real fusion effect. Former calibration methods require the doctor user to conduct complex manual procedures before usage. This paper introduces a novel motionless virtual-real calibration method. The method only requires to take a mixed reality image containing both virtual and real marker balls using the built-in forward camera of the AR glasses. The mapping relationship between the virtual and real spaces is calculated by using the camera coordinate system as a transformation medium. The composition and working process of the AR navigation system is introduced, and then the mathematical principle of the calibration is designed. The feasibility of the proposed calibration scheme is verified with a verification experiment, and the average registration accuracy of the scheme is around 5.80mm, which is of same level of formerly reported methods. The proposed method is convenient and rapid to implement, and the calibration accuracy is not dependent on the user experience. Further, it can potentially realize the real-time update of the registration transformation matrix, which can improve the AR fusion accuracy when the AR glasses moves. This motionless calibration method has great potential to be applied in future clinical navigation research.

Augmented Reality Surgical Navigation System for External Ventricular Drain

Augmented reality surgery systems are playing an increasing role in the operating room, but applying such systems to neurosurgery presents particular challenges. In addition to using augmented reality technology to display the position of the surgical target position in 3D in real time, the application must also display the scalpel entry point and scalpel orientation, with accurate superposition on the patient. To improve the intuitiveness, efficiency, and accuracy of extra-ventricular drain surgery, this paper proposes an augmented reality surgical navigation system which accurately superimposes the surgical target position, scalpel entry point, and scalpel direction on a patient’s head and displays this data on a tablet. The accuracy of the optical measurement system (NDI Polaris Vicra) was first independently tested, and then complemented by the design of functions to help the surgeon quickly identify the surgical target position and determine the preferred entry point. A tablet PC was used to display the superimposed images of the surgical target, entry point, and scalpel on top of the patient, allowing for correct scalpel orientation. Digital imaging and communications in medicine (DICOM) results for the patient’s computed tomography were used to create a phantom and its associated AR model. This model was then imported into the application, which was then executed on the tablet. In the preoperative phase, the technician first spent 5–7 min to superimpose the virtual image of the head and the scalpel. The surgeon then took 2 min to identify the intended target position and entry point position on the tablet, which then dynamically displayed the superimposed image of the head, target position, entry point position, and scalpel (including the scalpel tip and scalpel orientation). Multiple experiments were successfully conducted on the phantom, along with six practical trials of clinical neurosurgical EVD. In the 2D-plane-superposition model, the optical measurement system (NDI Polaris Vicra) provided highly accurate visualization (2.01 ± 1.12 mm). In hospital-based clinical trials, the average technician preparation time was 6 min, while the surgeon required an average of 3.5 min to set the target and entry-point positions and accurately overlay the orientation with an NDI surgical stick. In the preparation phase, the average time required for the DICOM-formatted image processing and program import was 120 ± 30 min. The accuracy of the designed augmented reality optical surgical navigation system met clinical requirements, and can provide a visual and intuitive guide for neurosurgeons. The surgeon can use the tablet application to obtain real-time DICOM-formatted images of the patient, change the position of the surgical entry point, and instantly obtain an updated surgical path and surgical angle. The proposed design can be used as the basis for various augmented reality brain surgery navigation systems in the future.

Two-dimensional C-arm robotic navigation system (i-Navi) in spine surgery: a pilot study.

Pedicle screws placement is very common procedure in spinal surgery. Robotic assisted surgery has been widely used in this operation. We assessed the accuracy of thoracolumbar spine trans-pedicle screws (TPS) implantation utilizing a noval robotic navigation system (i-Navi robotic navigation system) by planning with two-dimensional (2-D) C-arm. This study was approved by the Institutional Review Board of the Cathay General Hospital on June 21, 2018 (IRB number: CGH-P 106,092), and written informed consents were obtained from all the patients. There are 18 patients were enrolled in the study. All the patients received the posterior fusion with TPS insertion under the assistant of our robotic navigation system. There are 18 patients were included into our study, there are 2 patients were quitted from the study due to the equipment setup was not complete. Other 16 patients completed the entire procedure successfully. There is total 88 pedicle screws were inserted through i-Navi robotic navigation system. There are 79 of 88 screws were graded A, and 9 screws were graded B; no screws were graded C or D. No vascular or nerve injuries were noted after the operations. We present our i-Navi robotic navigation system, by planning with 2-D C-arm imaging and pre-operative CT scans. According to the results of study, we think it can provide a reliable and easy tool to perform the TPS in thoracic lumbar spine surgery.

Surgical Navigation System for Hypertensive Intracerebral Hemorrhage Based on Mixed Reality.

Hypertensive intracerebral hemorrhage (HICH) is an intracerebral bleeding disease that affects 2.5 per 10,000 people worldwide each year. An effective way to cure this disease is puncture through the dura with a brain puncture drill and tube; the accuracy of the insertion determines the quality of the surgery. In recent decades, surgical navigation systems have been widely used to improve the accuracy of surgery and minimize risks. Augmented reality- and mixed reality-based surgical navigation is a promising new technology for surgical navigation in the clinic, aiming to improve the safety and accuracy of the operation. In this study, we present a novel multimodel mixed reality navigation system for HICH surgery in which medical images and virtual anatomical structures can be aligned intraoperatively with the actual structures of the patient in a head-mounted device and adjusted when the patient moves in real time while under local anesthesia; this approach can help the surgeon intuitively perform intraoperative navigation. A novel registration method is used to register the holographic space and serves as an intraoperative optical tracker, and a method for calibrating the HICH surgical tools is used to track the tools in real time. The results of phantom experiments revealed a mean registration error of 1.03mm and an average time consumption of 12.9min. In clinical usage, the registration error was 1.94mm, and the time consumption was 14.2min, showing that this system is sufficiently accurate and effective for clinical application.

Accuracy assessment of marker recognition using ultra wide angle camera

Modern devices that support augmented reality technology are widely used in various fields of human activity, including medicine. Head mounted displays may provide an attractive alternative to traditional surgery navigation systems because allow users to stand at the first point of view and interact with objects in their surroundings naturally. Thus, the object of research in this study is recognition accuracy of fiducial markers in zones where ultra-wide angle camera distort the most. This is motivated by the need to increase user workspace for interaction with markers compare to the workspace provided with such popular augmented reality device as Microsoft HoloLens 2. In this study, the recognition accuracy is evaluated using ArUco square markers with taking into account different marker sizes and their positions in the camera view space. The marker positions include the center of the camera view space as well as such zones where lenses distort the most as top left, top right, bottom left, and bottom right corners. Obtained results show that recognition accuracy is good enough to be applicable for surgical navigation and failures referred to the distortion occurs are available in less than 0.2 % of all cases. This gives a possibility to increase workspace for interaction with markers compare to the Microsoft HoloLens 2. At the same time, the workspace for interaction could not reach the actual view space of the camera since recognition fails in cases where marker’s body is partially visible in the captured image (i. e., marker position is at the image boundaries).