Augmented Reality Navigation System Research Articles

Laparoscopic hepatectomy for hepatocellular adenoma using the hepatic vein as anatomic markers,How I do it.(with video)

TechniqueHepatocellular adenoma (HCA) is a benign monoclonal tumour that originates from mature hepatocytes.Liver resection is recommended in case of overt malignant transformation to hepatocellular carcinoma.However, hepatobiliary surgeries are technically challenging in patients with giant HCA (GHCA) owing to the risk of catastrophic intraoperative bleeding and difficulty with its control during laparoscopic treatment. We present a technical note on the utilization of the hepatic vein as anatomical landmarks for laparoscopic removal of giant hepatic glands, without intraoperative ultrasonography and with the aid of an augmented reality navigation system during surgery. ResultsThis video shows aA 37-year-old man was recommended treatment for a progressively increasing HCA (from 3 to 10 cm in a year) involving the right hepatic vein (RHV), inferior vena cava (IVC) and middle hepatic vein (MHV), resulting in the invisibility of the above intrahepatic anatomic markers in CT. Laparoscopic hepatectomy was performed using the hepatic vein as anatomic markers in a treatment centre specialising in minimally invasive surgeries. The procedure involved fully mobilising the right liver, transecting the parenchyma along the demarcation line in the caudal-to-cranial direction, exposing the involved caudal MHV, isolating and transecting the involved RHV and preserving the integrity of the involved IVC. ConclusionsLaparoscopic hepatectomy for intractable GHCA using the involved intrahepatic anatomic markers is feasible and effective. It reduces pre-operative haemorrhage and open conversion rates while maximising postoperative hepatic function.

Clinical Application of an Augmented Reality Navigation System for Transforaminal Epidural Injection: A Randomized Controlled Trial.

Objectives: Augmented reality (AR) navigation systems are emerging to simplify and enhance the precision of medical procedures. Lumbosacral transforaminal epidural injection is a commonly performed procedure for the treatment and diagnosis of radiculopathy. Accurate needle placement while avoiding critical structures remains a challenge. For this purpose, we conducted a randomized controlled trial for our augmented reality navigation system. Methods: This randomized controlled study involved 28 patients, split between a traditional C-arm guided group (control) and an AR navigation guided group (AR-NAVI), to compare procedure efficiency and radiation exposure. The AR-NAVI group used a real-time tracking system displaying spinal structure and needle position on an AR head-mounted display. The procedural time and C-arm usage (radiation exposure) were measured. Results: All patients underwent successful procedures without complications. The AR-NAVI group demonstrated significantly reduced times and C-arm usage for needle entry to the target point (58.57 ± 33.31 vs. 124.91 ± 41.14, p < 0.001 and 3.79 ± 1.97 vs. 8.86 ± 3.94, p < 0.001). Conclusions: The use of the AR navigation system significantly improved procedure efficiency and safety by reducing time and radiation exposure, suggesting a promising direction for future enhancements and validation.

Single-center experience with Knee+™ augmented reality navigation system in primary total knee arthroplasty.

Computer-assisted systems obtained an increased interest in orthopaedic surgery over the last years, as they enhance precision compared to conventional hardware. The expansion of computer assistance is evolving with the employment of augmented reality. Yet, the accuracy of augmented reality navigation systems has not been determined. To examine the accuracy of component alignment and restoration of the affected limb's mechanical axis in primary total knee arthroplasty (TKA), utilizing an augmented reality navigation system and to assess whether such systems are conspicuously fruitful for an accomplished knee surgeon. From May 2021 to December 2021, 30 patients, 25 women and five men, underwent a primary unilateral TKA. Revision cases were excluded. A preoperative radiographic procedure was performed to evaluate the limb's axial alignment. All patients were operated on by the same team, without a tourniquet, utilizing three distinct prostheses with the assistance of the Knee+™ augmented reality navigation system in every operation. Postoperatively, the same radiographic exam protocol was executed to evaluate the implants' position, orientation and coronal plane alignment. We recorded measurements in 3 stages regarding femoral varus and flexion, tibial varus and posterior slope. Firstly, the expected values from the Augmented Reality system were documented. Then we calculated the same values after each cut and finally, the same measurements were recorded radiologically after the operations. Concerning statistical analysis, Lin's concordance correlation coefficient was estimated, while Wilcoxon Signed Rank Test was performed when needed. A statistically significant difference was observed regarding mean expected values and radiographic measurements for femoral flexion measurements only (Z score = 2.67, P value = 0.01). Nonetheless, this difference was statistically significantly lower than 1 degree (Z score = -4.21, P value < 0.01). In terms of discrepancies in the calculations of expected values and controlled measurements, a statistically significant difference between tibial varus values was detected (Z score = -2.33, P value = 0.02), which was also statistically significantly lower than 1 degree (Z score = -4.99, P value < 0.01). The results indicate satisfactory postoperative coronal alignment without outliers across all three different implants utilized. Augmented reality navigation systems can bolster orthopaedic surgeons' accuracy in achieving precise axial alignment. However, further research is required to further evaluate their efficacy and potential.

Feasibility and accuracy of a real-time depth-based markerless navigation method for hologram-guided surgery

BackgroundTwo-dimensional (2D) medical visualization techniques are often insufficient for displaying complex, three-dimensional (3D) anatomical structures. Moreover, the visualization of medical data on a 2D screen during surgery is undesirable, because it requires a surgeon to continuously switch focus. This switching focus problem also results in extensive use of intraoperative radiation to gain additional insights for a 3D configuration. The use of augmented reality (AR) has the potential to overcome these problems, for instance by using markers on target points that are aligned with the AR solution. However, placing markers for a precise virtual overlay are time-costly, always have to be visible within the field of view and disrupt the surgical workflow. In this study, we developed ARCUS, a depth-based, markerless AR navigation system, which overlays 3D virtual elements onto target body parts to overcome the limitations of 2D medical visualization techniques.Methods and resultsIn a phantom study, our markerless ARCUS system was evaluated for accuracy and precision by comparing it to a Quick Response (QR) code-based AR registration method. The evaluation involved measuring the Euclidean distance between target points on a 3D-printed face and their corresponding points on the virtual overlay using a robotic arm for precise measurements. Correlations between the measuring points provided by our markerless system and the actual measuring points on the 3D-print were high, with promising consistent Euclidean distances between the 3D points and the virtual points generated by both our markerless system and the Vuforia QR Code system. We also show two clinical examples of ex vivo case studies on cadaveric human specimens where our markerless ARCUS system could be applicable to.ConclusionThe markerless AR navigation system holds strong potential as a 3D visualization method in clinical settings. While both ARCUS and the Vuforia QR code-based method fell short of meeting the surgical threshold of a 2 mm offset, our markerless system demonstrated promising features such as instant registration, markerless operation, and potential compatibility with non-rigid structures. Its automated virtual overlay onto target body parts offers significant advantages, paving the way for investigations into future clinical use.

Augmented Reality Navigation System for Biliary Interventional Procedures With Dynamic Respiratory Motion Correction.

Biliary interventional procedures require physicians to track the interventional instrument tip (Tip) precisely with X-ray image. However, Tip positioning relies heavily on the physicians' experience due to the limitations of X-ray imaging and the respiratory interference, which leads to biliary damage, prolonged operation time, and increased X-ray radiation. We construct an augmented reality (AR) navigation system for biliary interventional procedures. It includes system calibration, respiratory motion correction and fusion navigation. Firstly, the magnetic and 3D computed tomography (CT) coordinates are aligned through system calibration. Secondly, a respiratory motion correction method based on manifold regularization is proposed to correct the misalignment of the two coordinates caused by respiratory motion. Thirdly, the virtual biliary, liver and Tip from CT are overlapped to the corresponding position of the patient for dynamic virtual-real fusion. Our system is respectively evaluated and achieved an average alignment error of 0.75 ± 0.17 mm and 2.79 ± 0.46 mm on phantoms and patients. The navigation experiments conducted on phantoms achieve an average Tip positioning error of 0.98 ± 0.15 mm and an average fusion error of 1.67 ± 0.34 mm after correction. Our system can automatically register the Tip to the corresponding location in CT, and dynamically overlap the 3D virtual model onto patients to provide accurate and intuitive AR navigation. This study demonstrates the clinical potential of our system by assisting physicians during biliary interventional procedures. Our system enables dynamic visualization of virtual model on patients, reducing the reliance on contrast agents and X-ray usage.

A Low-Cost Mobile-Based Augmented Reality Neuronavigation System for Retrosigmoid Craniotomy

BACKGROUND AND OBJECTIVES: The correct positioning of the transverse-sigmoid sinus junction (TSSJ) during retrosigmoid craniotomy (RC) is crucial for enhancing surgical efficiency and preventing complications. An augmented reality technology may provide low-cost guidance for the TSSJ position. The authors aimed to investigate the clinical application of a self-developed mobile augmented reality navigation system (MARNS) for TSSJ positioning during RC and present their findings. METHODS: This observational research enrolled patients who underwent RC at Fujian Provincial Hospital from May 2023 to June 2023. All patients had their TSSJs located by MARNS. The surgical incision and skull “keyhole” for drilling were determined separately based on the projections of TSSJ on the 3-dimensional model displayed by MARNS. This method was assessed using matching error, positioning time, integrity of the bone flap, incidence of transversal sigmoid sinus injury, and other complications. RESULTS: Seven patients diagnosed with acoustic neuroma, trigeminal neuralgia, and hemifacial spasm were enrolled in this study. The MARNS system exhibited a matching error with an average magnitude of 2.88 ± 0.69 mm. The positioning procedure necessitated an average duration of 279.71 ± 27.29 seconds. In every instance, the inner edge of the TSSJ was precisely identified and exposed while the bone flap was successfully formed and maintained an average integrity of 86.7%. CONCLUSION: This study demonstrated the efficacy of MARNS in the precise placement of the TSSJ during RC procedures. It offers advantages for convenience, cost-effectiveness, and reliability for neurosurgical navigation.

PEMBUATAN MODEL NAVIGASI BERBASIS AUGMENTED REALITY DENGAN METODE MARKERLESS DI GEDUNG RISE CENTER

The current navigation system is crucial as it can facilitate human location search. However, only a small number of buildings in Indonesia implement indoor navigation systems. An indoor or building-based Augmented Reality navigation system can save time because it combines virtual objects with the real physical world through a 3D path alignment that corresponds to real-world features. This system will assist users in finding their way within the RISE Center building when they first arrive or when they have difficulty locating specific rooms. The system uses markerless Augmented Reality and can determine the user's initial location when they are at the starting point or when they scan QR codes at specific points. This system has been tested in the RISE Center building of the Faculty of Engineering and Science at Ibn Klahdun University (UIKA), Bogor. The results demonstrate that the system can serve as an effective platform for displaying location information without requiring an internet connection.

A game-based augmented reality navigation system to support makerspace user education in a university library

PurposeA makerspace has recently been identified as an essential learning field for cultivating students’ creative and thinking abilities. Creating a makerspace service within a university library is vital, as it fosters innovation, interdisciplinary learning, practical skills, entrepreneurship and career readiness while transforming the library into a dynamic centre for hands-on education and collaboration. Nevertheless, the wide-ranging functions and uses of makerspace equipment can potentially lead to a situation where librarians are overwhelmed by their duties due to manpower constraints. Therefore, this study aims to develop a novel game-based augmented reality navigation system (GARNS) based on the Octalysis gamification framework and scaffolding theory to support makerspace user education, hoping to promote learners’ learning motivation and their immersive experience and to enhance the learning performance of makerspace user education.Design/methodology/approachWith a true experimental research method, 24 grade 11 students from a high school in Keelung City, Taiwan, were recruited to participate in the experiment on makerspace user education. Among them, ten students were randomly assigned to the experimental group using the GARNS and the other seven students were randomly assigned to a control group using the Web navigation system. The remaining seven students were assigned to a second control group using the narrative guided tour with a librarian to conduct makerspace user education.FindingsAnalytical results show that learners can achieve significant learning effectiveness using the GARNS, Web navigation system or traditional narrative guided tour with a librarian for makerspace user education. There were no significant differences in learning effectiveness and motivation neither between the GARNS group and the narrative guided tour with a librarian group nor between the Web navigation system group and the narrative guided tour with a librarian group. However, there were significant differences in learning effectiveness and motivation in terms of the value and expectation dimensions of learning motivation between the GARNS group and the Web navigation system group, and the GARNS group was significantly better than the Web navigation system group.Practical implicationsThe study’s practical implication on makerspace user education is to reduce the manpower of a university library with makerspace services by the proposed GARNS that can offer a practical solution to enhance the learning effectiveness and motivation of makerspace through immersive game-based autonomous learning. Additionally, the study’s theoretical contribution lies in its innovative combination of game-based learning and scaffolding theory, while its practical significance stems from its potential to revolutionize makerspace user education, enhance motivation and performance and influence the broader landscape of educational technology.Originality/valueThis study combines game-based learning with augmented reality tools to develop a novel GARNS, which provides an innovative and effective learning tool suitable for the characteristics of makerspace and contributes to promoting makerspace user education and diversified learning modes. Additionally, most interviewees believed that using GARNS for educating makerspace users could assist them in consistently evaluating, choosing and discovering educational tasks in a library makerspace. This study contributes to promoting the popularization of makerspace user education.

Early effectiveness of computer navigation system-assisted transiliac-transsacral screws placement for posterior pelvic ring injuries

To investigate the early effectiveness of transiliac-transsacral screws internal fixation assisted by augmented reality navigation system HoloSight (hereinafter referred to as "computer navigation system") in the treatment of posterior pelvic ring injuries. A retrospective analysis was made in the 41 patients with posterior pelvic ring injuries who had been treated surgically with transiliac-transsacral screws between June 2022 and June 2023. The patients were divided into navigation group (18 cases, using computer navigation system to assist screw implantation) and freehand group (23 cases, using C-arm X-ray fluoroscopy to guide screw implantation) according to the different methods of transiliac-transsacral screws placement. There was no significant difference in gender, age, body mass index, causes of injuries, Tile classification of pelvic fracture, days from injury to operation, usage of unlocking closed reduction technique between the two groups ( P>0.05). The time of screw implantation, the fluoroscopy times, the guide wire adjustment times of each screw, and the incidence of complications were recorded and compared between the two groups. The position of the transiliac-transsacral screw was scanned by CT within 2 days after operation, and the position of the screw was classified according to Gras standard. The operation was successfully completed in both groups. The time of screw implantation, the fluoroscopy times, and the guide wire adjustment times of each screw in the navigation group were significantly less than those in the freehand group ( P<0.05). There were 2 cases of incision infection in the freehand group, and the incision healed by first intention after active dressing change; there was no screw-related complication in the navigation group during operation and early period after operation; the difference in incidence of complications between the two groups (8.7% vs. 0) was not significant ( P=0.495). According to the Gras standard, the screw position of the navigation group was significantly better than that of the freehand group ( P<0.05). Compared with the traditional freehand method, the computer navigation system assisted transiliac-transsacral screws internal fixation in the treatment of posterior pelvic ring injuries has advantages of improving the accuracy of screw implantation and reducing radiation damage and the time of screw implantation.

Indoor Campus Navigation Using Augmented Reality

Abstract—Augmented Reality can now be used for a variety of things including educational purposes, businesses, tourism, museum illustrations, manufacturing and marketing as well. One of the parts Augmented Reality is highly exercised and researched, is the Indoor Navigation, Indoor Navigation can be applied in campuses, malls, multiplexes, offices etc., basically where the area is huge, and we need to locate a particular place in that huge indoors. Because in these places what happens is a lot of new visitors enter who are not familiar with the place, and so they keep on searching for their desired location and waste a lot of time in it. So that is the problem that is solved through AR Navigation System. Indoor Campus Navigation Using Augmented reality, which provides people with essential AR direction and Drop-down buttons which consist of destination names. The aim for our project is to direct user to different areas of the campus and alert user about the areas they are passing through with a mini-map. For indoor navigation augmented reality uses inbuilt characteristics to determine a person's position and provide the necessary navigation directives. The project makes use of technology like UNITY, AR CORE, AR FOUNDATION, and NAVMESH etc. Keywords: Indoor campus Navigation system, Augmented Reality(AR),Navmesh, AR Foundation, Unity

Augmented reality navigation-guided intraoperative pulmonary nodule localization: a pilot study.

With the increasing number of small pulmonary nodules detected, effective localization of pulmonary nodules has become an issue. The goal of this study is to determine the safety and feasibility of a newly developed augmented reality navigation technology for intraoperative localization of small pulmonary nodules. We conducted a prospective single-center feasibility study of a novel augmented reality navigation system and lung localization (LungBrella) marker on ten patients between July and October 2020. For augmented reality navigation-guided localization, a preoperative chest computed tomography scan was performed to generate 3-dimensional (3D) virtual images and individualized localization plan, which were uploaded into Hololens (a head-mounted augmented reality device). Under the guidance of established procedure plan displayed by HoloLens, localization marker was placed in operating room. Segmentectomy or wedge resection was subsequently performed. The primary endpoint was the localization procedure success rate, and the secondary endpoints were localization time, operation time, and complications. Localization was successful in seven of the ten procedures. Due to different reasons, failures were noted in three cases, after which immediate adjustments were made. In the successful cases, the LungBrella marker was positioned at a median of 5.8 mm (range, 0-10 mm) from the edge of the nodule. Median localization time was 9.4 min (range, 5-19 min), and median operation time was 172.9 min (range, 105-200 min). There were no complications during the entire process. This exploratory study suggests that augmented reality navigation-guided pulmonary nodule localization is a safe and feasible technique (ClinicalTrials.gov identifier, NCT04211051).

Bone biopsies guided by augmented reality: a pilot study

PurposeTo test the technical feasibility of an augmented reality (AR) navigation system to guide bone biopsies.MethodsWe enrolled patients subjected to percutaneous computed tomography (CT)-guided bone biopsy using a novel AR navigation system. Data from prospectively enrolled patients (AR group) were compared with data obtained retrospectively from previous standard CT-guided bone biopsies (control group). We evaluated the following: procedure duration, number of CT passes, patient’s radiation dose (dose-length product), complications, and specimen adequacy. Technical success was defined as the ability to complete the procedure as planned, reaching the target center. Technical efficacy was assessed evaluating specimen adequacy.ResultsEight patients (4 males) aged 58 ± 24 years (mean ± standard deviation) were enrolled in the AR group and compared with 8 controls (4 males) aged 60 ± 15 years. No complications were observed. Procedure duration, number of CT passes, and radiation dose were 22 ± 5 min, 4 (median) [4, 6 interquartile range] and 1,034 ± 672 mGy*cm for the AR group and 23 ± 5 min, 9 [7.75, 11.25], and 1,954 ± 993 mGy*cm for controls, respectively. No significant differences were observed for procedure duration (p = 0.878). Conversely, number of CT passes and radiation doses were significantly lower for the AR group (p < 0.001 and p = 0.021, respectively). Technical success and technical efficacy were 100% for both groups.ConclusionsThis AR navigation system is safe, feasible, and effective; it can decrease radiation exposure and number of CT passes during bone biopsies without increasing duration time.Relevance statementThis augmented reality (AR) navigation system is a safe and feasible guidance for bone biopsies; it may ensure a decrease in the number of CT passes and patient’s radiation dose.Key points• This AR navigation system is a safe guidance for bone biopsies.• It ensures decrease of number of CT passes and patient’s radiation exposure.• Procedure duration was similar to that of standard CT-guided biopsy.• Technical success was 100% as in all patients the target was reached.• Technical efficacy was 100% as the specimen was adequate in all patients.Graphical

Augmented Reality Navigation System and Indocyanine Green Fluorescence Imaging Make Laparoscopic Right Anterior Sectionectomy More Precisely and Safely

BackgroundLaparoscopic right anterior sectionectomy (LRAS) is an attractive surgical option for tumors in the right anterior section (RAS), which can remove tumor-bearing segments while sparing more normal liver tissue1. However, the definition of the resection plane, the guidance during the resection, and the protection of the right posterior hepatic duct are still the key points of this procedure2. Our center attempted to use augmented reality navigation system and indocyanine green fluorescence (ICG) imaging technology to solve these difficulties3, and reported this in LRAS for the first time. MethodsA 47-year-old female was admitted to our institution for a tumor in the RAS. Therefore, LRAS was performed. First, a virtual liver segment projection combined with the ischemic line caused by the occlusion of RAS blood flow was used to mark the RAS boundary, and it was confirmed using the ICG negative staining. Then, during the parenchymal transection, the precise resection plane was guided assisted by the ICG fluorescence imaging system. In addition, the right anterior Glissonean pedicle (RAGP) was divided using a linear stapler after confirming the spatial relationship of the bile duct using ICG fluorescence imaging. ResultsThe operation lasted 360 min with 100 mL of intraoperative blood loss. There were no postoperative complications, and the patient was discharged after 8 days. ConclusionThe augmented reality navigation system plus ICG imaging can make LRAS more precisely and safely.

Efficacy of a Novel Augmented Reality Navigation System Using 3D Computer Graphic Modeling in Endoscopic Transsphenoidal Surgery for Sellar and Parasellar Tumors

In endoscopic transsphenoidal skull base surgery, knowledge of tumor location on imaging and the anatomic structures is required simultaneously. However, it is often difficult to accurately reconstruct the endoscopic vision of the surgical field from the pre-surgical radiographic images because the lesion remarkably displaces the geography of normal anatomic structures. We created a precise three-dimensional computer graphic model from preoperative radiographic data that was then superimposed on a visual image of the actual surgical field and displayed on a video monitor during endoscopic transsphenoidal surgery. We evaluated the efficacy of this augmented reality (AR) navigation system in 15 consecutive patients with sellar and parasellar tumors. The average score overall was 4.7 [95% confidence interval: 4.58-4.82], which indicates that the AR navigation system was as useful as or more useful than conventional navigation in certain patients. In two patients, AR navigation was assessed as less useful than conventional navigation because perception of the depth of the lesion was more difficult. The developed system was more useful than conventional navigation for facilitating an immediate three-dimensional understanding of the lesion and surrounding structures.

IMAGINER - Improving accuracy with a Augmented Reality Navigation system during placement of external ventricular drains: A feasibility study

IMAGINER - Improving accuracy with a Augmented Reality Navigation system during placement of external ventricular drains: A feasibility study

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.

Indoor AR Navigation and Emergency Evacuation System Based on Machine Learning and IoT Technologies

In order to evacuate people safely and quickly in indoor disaster environments, it is necessary to estimate the current location of the individuals, detect disaster situations, predict disaster propagation, derive optimal individual escape paths, and implement a user-friendly and intuitive guidance system. In this study, we propose a machine-learning-based indoor augmented reality (AR) navigation and emergency evacuation system that can guide an optimal escape path for individual users. To detect emergency events and deliver sensing data, an Internet of Things (IoT)-enabled ad hoc network is considered. To deliver the sensing data safely and reliably to the server, we present a hybrid reinforcement-learning-based routing algorithm that combines direct and indirect <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> -learning methods. Prediction of disaster propagation at multiple time scales is important to prevent dangerous situations. We propose a simple disaster area prediction method that ensembles elementary component gradient boosting machine models. User location is estimated by a deep neural network using the received signal strength from beacon nodes. To derive the optimum evacuation path for each individual, we propose a novel model-based <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> -learning method, in which we consider the building structural model and disaster context information. The performance of the proposed system is experimentally evaluated for various disaster scenarios.

Validation of a Prototype Augmented Reality Navigation System for Total Hip Replacement.

Assistive technologies are becoming more common in total hip replacement (THR) procedures, improving surgeons' abilities to achieve target implant orientations. These systems can be large, absorbing limited space in the operating theatre, and they can add complexity to surgery. We developed a small footprint prototype system that can assist in the accurate placement of implant components using augmented reality (AR) technology into preoperatively planned positions. This technology augments the 3D pelvis and the cup in its target position and displays the real-time position of instruments. The accuracy of the developed prototype system was assessed through a cadaveric study, comparing the achieved implant positions to the preoperative target. All cadavers received preoperative 3D planning to identify the target cup position and orientation. Cadaveric surgeries were completed using the AR system to achieve the target cup placement. Postoperative computed tomography (CT) was used to measure the achieved component position for each hip. The mean absolute deviation (range) from target acetabular placement to the achieved acetabular placement was 2.9° (-8.7 to 3.3°), 3.0° (-5.7 to 7°) and 1.6mm (-1.2 to 3.5mm) for inclination, anteversion, and depth, respectively. Sixty-six percent of results were within +/-5° of the preoperative target orientation. We present a cadaver validation study on a small footprint prototype system using augmented reality to enable accurate cup placement and provide additional information intraoperatively. Our results are comparable with reported results for image-based navigation from the literature.

Preliminary reports of augmented-reality assisted craniofacial bone fracture reduction

Zygomaticomaxillary complex fractures involve four fracture ends. It is difficult to fully expose the operative area through a main coronal incision, an intraoral incision, and an eyelid incision. To address the partial visual field loss in craniofacial fracture reduction, we attempted to use an augmented reality (AR) navigation system. Patients with zygomaticomaxillary complex fractures underwent three-dimensional (3D) computed tomography (CT) modeling before surgery, and preoperative plans were designed. The control team used traditional optical navigation to perform the surgery. The experimental team used an AR navigation system. From May 2019 to December 2019, 10 patients with zygomaticomaxillary complex fractures were included in this study. Data were collected after surgery and analyzed. There was a significant difference between the two groups in the fracture point error (1.35 vs. 1.61, P=0.02) and fracture reduction time (15.40 vs. 20.40, P=0.03). However, there was no difference in the operative duration (6.60 vs. 6.65, P=0.92), blood loss volume (620.00vs. 580.00, P=0.83), or incidence of complications. The AR navigation system used by the research team has good auxiliary effects for reducing zygomaticomaxillary complex fractures. The new surgical method has better accuracy and a shorter reduction time than the traditional surgical method.

An accurate 3D augmented reality navigation system with enhanced autostereoscopic display for oral and maxillofacial surgery.

Oral and maxillofacial surgery demands high precision navigation to achieve optimal surgical outcomes. Augmented reality (AR) has been a promising solution for intuitive and accurate guidance, whereas existing systems have room for improvement. We propose a high quality and accurate in situ AR navigation system. Enhanced image quality is achieved by deploying eye tracking in lenticular-based autostereoscopic display. Viewpoint tracking and optical tracking are integrated to assure accurate in situ images. The proposed system can provide in situ AR images in real-time, with a viewing angle of 59.5°×49.1°, 3D image resolution of 0.35×0.21mm, and image accuracy of 0.99±0.70mm. A maxillary drilling experiment obtains average position error of 1.12±0.30mm and localization time of 8.7±3.9s, significantly better than conventional 2D navigation system. The proposed system can display high-quality AR images and therefore reduce positioning error and operating time.