Virtual Navigation System Research Articles

Three-Dimensional Documentation and Virtual Web Navigation System for the Indoor and Outdoor Exploration of a Complex Cultural Heritage Site

Three-Dimensional Documentation and Virtual Web Navigation System for the Indoor and Outdoor Exploration of a Complex Cultural Heritage Site

A proximal policy optimization with curiosity algorithm for virtual drone navigation

The drone sector is witnessing a surge in demand for advanced models tailored to address critical applications such as disaster management and intelligent warehouse deliveries. Employing simulation-based experiments with virtual drone navigation is considered a best practice before deploying physical models. Nonetheless, the current state-of-the-art virtual drone navigation system lacks accuracy and introduces notable increments in simulation time. In order to mitigate these issues, this paper introduces a deep reinforcement learning-based drone agent, designed to autonomously navigate within a constrained virtual environment. The proposed drone agent utilizes realistic drone physics in order to ensure flight within the virtual environment. The work uniquely combines & optimizes both control algorithms and physical dynamics, making the model more robust and versatile than others. The integration of curiosity-driven learning with physics-based modeling potentially increases the model's readiness for real-world application, compared to theoretical approaches. The extensive simulation results validate the remarkable speed and accuracy of the proposed scheme compared to baseline works. The trained agent exhibits strength and versatility, enabling it to deal with the numerous targets and obstacles encountered in human environments.

Custom Voice Cloner

The Custom Voice Cloner is based on voice signal speech synthesizer. It is a technology that converts text into audible speech, simulating human speech characteristics like pitch and tone. It finds applications in virtual assistants, navigation systems, and accessibility tools. Building one in Python typically involves Text-to-Speech (TTS) libraries such as gTTS, pyttsx3, or platform-specific options for Windows and macOS, offering easy text-to-speech conversion.However, TTS libraries might lack customization and voice quality needed for advanced projects. For more sophisticated applications, custom voice synthesizers can be built using deep learning techniques like Tacotron and WaveNet. These models learn speech nuances for more natural output.Creating a custom voice synthesizer is challenging, requiring high-quality training data, machine learning expertise, and substantial computational resources. It goes beyond generating speech to convey emotions and nuances in pronunciation for natural and expressive voices. Key Word: Voice signal speech synthesizer,text-to-speech conversion, deep learning,TTS, gTTS, pyttsx3,etc.

WEB EXPLORATION OF CULTURAL HERITAGE WITH LIMITED ACCESSIBILITY: FIRST EXPERIMENTATION FOR HYPOGEUM ARCHAEOLOGICAL SITES

Abstract. The accessibility to hypogeum archaeological sites is still one of the main challenges for the dissemination of Cultural Heritage knowledge, especially in the territories rich of ancient ruins like the Mediterranean area, where modern cities often hide underground ruins of historical settlements making the accessibility of these sites very difficult or even impossible. Digital reconstructions and virtual reality applications result in many cases the only chance to explore these archaeological sites. Terrestrial laser scanning and photogrammetry are the main technologies able now to digitise at a very high-level detail the hypogeum environments, whilst web virtual navigation systems are smart solutions for their dissemination and virtual fruition. However, this approach has some critical issues since the online virtual fruition needs further 3D model elaborations and web design processes. The work aims to develop and implement a web exploration system for the web fruition of hypogeum archaeological sites. The research was carried out on two hypogeum sites in Marsala (Italy), part of the ancient Roman city of Lylibaeum. The system was developed using WebGL JavaScript open-source libraries, allowing the construction of a virtual 3D navigation platform accessible on the web. In particular, in this work, the 3D dataset elaboration necessary to solve the limitations relative to the web browsing of complex 3D datasets is investigated and a possible smart solution based on open-source technology is proposed.

A LiDAR–Inertial SLAM Method Based on Virtual Inertial Navigation System

In scenarios with insufficient structural features, LiDAR-based SLAM may suffer from degeneracy, resulting in impaired robot localization and mapping and potentially leading to subsequent deviant navigation tasks. Therefore, it is crucial to develop advanced algorithms and techniques to mitigate the degeneracy issue and ensure the robustness and accuracy of LiDAR-based SLAM. This paper presents a LiDAR–inertial simultaneous localization and mapping (SLAM) method based on a virtual inertial navigation system (VINS) to address the issue of degeneracy. We classified different gaits and match each gait to its corresponding torso inertial measurement unit (IMU) sensor to construct virtual foot inertial navigation components. By combining an inertial navigation system (INS) with zero-velocity updates (ZUPTs), we formed the VINS to achieve real-time estimation and correction. Finally, the corrected pose estimation was input to the IMU odometry calculation procedure to further refine the localization and mapping results. To evaluate the effectiveness of our proposed VINS method in degenerate environments, we conducted experiments in three typical scenarios. The results demonstrate the high suitability and accuracy of the proposed method in degenerate scenes and show an improvement in the point clouds mapping effect. The algorithm’s versatility is emphasized by its wide applicability on GPU platforms, including quadruped robots and human wearable devices. This broader potential range of applications extends to other related fields such as autonomous driving.

Patient-specific virtual three-dimensional surgical navigation for gastric cancer surgery: A prospective study for preoperative planning and intraoperative guidance.

Abdominal computed tomography (CT) can accurately demonstrate organs and vascular structures around the stomach, and its potential role for image guidance is becoming increasingly established. However, solely using two-dimensional CT images to identify critical anatomical structures is undeniably challenging and not surgeon-friendly. To validate the feasibility of a patient-specific 3-D surgical navigation system for preoperative planning and intraoperative guidance during robotic gastric cancer surgery. A prospective single-arm open-label observational study was conducted. Thirty participants underwent robotic distal gastrectomy for gastric cancer using a virtual surgical navigation system that provides patient-specific 3-D anatomical information with a pneumoperitoneum model using preoperative CT-angiography. Turnaround time and the accuracy of detecting vascular anatomy with its variations were measured, and perioperative outcomes were compared with a control group after propensity-score matching during the same study period. Among 36 registered patients, 6 were excluded from the study. Patient-specific 3-D anatomy reconstruction was successfully implemented without any problems in all 30 patients using preoperative CT. All vessels encountered during gastric cancer surgery were successfully reconstructed, and all vascular origins and variations were identical to operative findings. The operative data and short-term outcomes between the experimental and control group were comparable. The experimental group showed shorter anesthesia time (218.6 min vs. 230.3 min; P=0.299), operative time (177.1 min vs. 193.9 min; P=0.137), and console time (129.3 min vs. 147.4 min; P=0.101) than the control group, although the differences were not statistically significant. Patient-specific 3-D surgical navigation system for robotic gastrectomy for gastric cancer is clinically feasible and applicable with an acceptable turnaround time. This system enables patient-specific preoperative planning and intraoperative navigation by visualizing all the anatomy required for gastrectomy in 3-D models without any error. Clinicaltrials.gov, identifier NCT05039333.

Pilot study of archimedes virtual bronchoscopic navigation system-guided biopsy to diagnose lung nodules in children.

Peripheral pulmonary lesions are uncommon in children. Bronchoscopy is a minimal invasive method to obtain a diagnostic lung biopsy. However, due to the lack of effective guidance methods, the diagnostic efficacy of transbronchial lung biopsy for peripheral solitary pulmonary diseases is still limited. Is the Archimedes virtual bronchoscopic navigation system safe and effective for the diagnosis of peripheral pulmonary lesions in children? This pilot study retrospectively analyzed the clinical features, radiological characteristics, operation processes, intra-and postoperative complications, and pathological results of five children who underwent Archimedes-guided biopsy of peripheral pulmonary lesions in Beijing Children's Hospital from May 2021 to May 2022. The cohort comprised five children (all males) with age of 7.1-15.8 years. A guide sheath was inserted through the bronchoscope under the guidance of Archimedes combined with radial endobronchial ultrasound to complete the biopsy under general anesthesia. The fused fluoroscopy technique was used to reconfirm the location of the forceps prior to biopsy in all children. The forceps reached the lesion under the guidance of the navigation and the samples were collected successfully in all children. Pathological examination of the biopsy specimens showed Epstein-Barr virus infection-related lymphoproliferative disease in one child, pulmonary metastasis of rhabdomyosarcoma in one child, and pulmonary vasculitis in one child; high-throughput sequencing of the biopsy tissue sample identified Mycobacterium tuberculosis (sequence no. 80) in one child and Aspergillus (sequence no. 40) in another child. All five children tolerated the biopsy procedure without developing postoperative complications, such as pneumothorax and hemoptysis. Archimedes-guided bronchoscopic lung biopsy is a feasible and efficient way to diagnose peripheral pulmonary lesions in children with manageable complications.

Vehicle Positioning Algorithm Based on NHC/Virtual-MINS/OD

Aiming at the problem of large navigation errors for unmanned vehicle based on MEMS inertial navigation systems (MEMS-INS, MINS) due to low output accuracy of MEMS inertial sensors, a redundant MINS is designed and a high precision positioning algorithm is proposed. In redundant MINS, the output of the redundant gyroscopes is estimated by the improved virtual gyro algorithm based on improved current statistical model and interacting multiple model Kalman filter (ICS-IMMKF). The weighted fusion algorithm is used to fuse the redundant accelerometer information, thus the virtual micro inertial navigation system (Virtual-MINS) is obtained. In the process of vehicle positioning based on virtual MINS, the centripetal acceleration is solved based on the kinematic constraints. Combined with the navigation information of Virtual-MINS and odometer (OD), the difference of centripetal acceleration and velocity are used as observation, and a Virtual-MINS/OD positioning algorithm based on kinematic nonholonomic constraints (NHC/Virtual-MINS/OD) is proposed. The simulation results show that the ICS-IMMKF algorithm can achieve high precision fusion of redundant gyro. In the test, azimuth maneuver is not constrained by the ground, therefore the ICS-IMMKF algorithm can obtain the azimuth rate with high precision. The experimental results show that the root mean square (RMS) of the East and North positioning errors, as well as the RMS of pitch, roll and azimuth estimation error based on the NHC/Virtual-MINS/ OD positioning algorithm are reduced to 34.15%, 22.65%, 55.11%, 64.93% and 41.37% of the NHC/#1-MINS/OD positioning algorithm, respectively. The method will provide a solution for high-precision positioning when GNSS fails.

Manual route modification using an oblique method following automatic virtual bronchoscopic navigation.

Virtual automatic bronchoscopic navigation (VBN) systems to determine the route to peripheral pulmonary lesions (PPLs) in lung cancer can improve diagnostic biopsy yields. However, compared with VBN, drawing manual routes using computed tomography images, especially with oblique methods, can identify more routes. The Ziostation2 VBN system combines the benefits of these 2 methods; we evaluated this performance by comparing 3 different route-determining methods.We retrospectively collected data from 50 patients with PPLs measuring <30 mm who underwent transbronchial biopsy with an ultrathin bronchoscope at the Osaka International Cancer Institute during January to December 2018. We compared automatic VBN (Ziostation2), manual route modification using an oblique method after automatic VBN, and manual navigation using a general application computed tomography viewer. Concordance between predicted and actual branching were determined. We also compared the predicted relationship between the terminal bronchi and the lesion by 2 of the methods with ultrasonographic images (radial-probe endobronchial ultrasonography [radial-EBUS]).Manual modification after automatic VBN significantly increased the rate of determining routes to the target (66%) versus with the automatic VBN alone (32%) (P < .001). Expected route bifurcations were exact matches with actual branching in 45/48 of the patients using manual modification after automatic VBN. The predicted relationship between the terminal bronchi and the lesion using manual modification after VBN matched the radial-EBUS images in 35/50 of the patients.Manual modification of routes to PPLs using an oblique method after automatic VBN predicted actual radial-EBUS route imaging and could help determine appropriate patients for bronchoscopy.

Reconsidering Ventriculoperitoneal Shunt Surgery and Postoperative Shunt Valve Pressure Adjustment: Our Approaches Learned From Past Challenges and Failures.

Treatment for idiopathic normal pressure hydrocephalus (iNPH) continues to develop. Although ventriculoperitoneal shunt surgery has a long history and is one of the most established neurosurgeries, in the 1970s, the improvement rate of iNPH triad symptoms was poor and the risks related to shunt implantation were high. This led experts to question the surgical indication for iNPH and, over the next 20 years, cerebrospinal fluid (CSF) shunt surgery for iNPH fell out of favor and was rarely performed. However, the development of programmable-pressure shunt valve devices has reduced the major complications associated with the CSF drainage volume and appears to have increased shunt effectiveness. In addition, the development of support devices for the placement of ventricular catheters including preoperative virtual simulation and navigation systems has increased the certainty of ventriculoperitoneal shunt surgery. Secure shunt implantation is the most important prognostic indicator, but ensuring optimal initial valve pressure is also important. Since over-drainage is most likely to occur in the month after shunting, it is generally believed that a high initial setting of shunt valve pressure is the safest option. However, this does not always result in sufficient improvement of the symptoms in the early period after shunting. In fact, evidence suggests that setting the optimal valve pressure early after shunting may cause symptoms to improve earlier. This leads to improved quality of life and better long-term independent living expectations. However, in iNPH patients, the remaining symptoms may worsen again after several years, even when there is initial improvement due to setting the optimal valve pressure early after shunting. Because of the possibility of insufficient CSF drainage, the valve pressure should be reduced by one step (2–4 cmH2O) after 6 months to a year after shunting to maximize symptom improvement. After the valve pressure is reduced, a head CT scan is advised a month later.

Multi-Dimensional Display of Wang's Lymph Node Map Using Virtual Bronchoscopic Navigation System.

Background: Transbronchial needle aspiration (TBNA) is a classical technique for diagnosing mediastinal-hilar lymph node enlargement. However, the diagnostic value of conventional TBNA (cTBNA) is limited in small lymph nodes. Methods: Here, we generated an innovative multi-dimensional virtual lymph node map on top of Wang’s lymph node map using a Lungpoint Virtual Bronchoscopic Navigation System. Results: The virtual bronchoscopic navigation (VBN) system was combined with computed tomography (CT) images to generate extrabronchial, endobronchial, sagittal, coronal as well as horizontal views of the 11 intrathoracic lymph node stations and their adjacent tissues and blood vessels. We displayed the specific puncture site of each lymph node station. The 11 stations were divided into four groups: right mediastinal stations, left mediastinal stations, central mediastinal stations and hilar stations. Conclusion: The VBN system provides a precise view of the intrabronchial landmarks, which may increase the diagnostic accuracy of intrathoracic lymph node adenopathy and assist bronchoscopists with practicing TBNA.

Mixed Assessment of Virtual Serious Games Applied in Architectural and Urban Design Education.

The creation and usage of serious games on virtual reality (VR) and/or interactive platforms for the teaching of architecture, construction, urban planning, and other derived areas, such as security and risk prevention, require design processes, studies, and research that lead to further consolidation expansion. In that sense, this paper presents two main aims developed: the improvement of a virtual navigation system through the results of previous user studies and mixed research (quantitative and qualitative) improved based on the user perception for educational and professional uses. The VR system used is based on Unreal Engine programming of the HTC Vive sensor. This study is related to the GAME4City 3.0 and a broader project focused on gamified visualization and its educational uses in architectural and urban projects. The results reflect great interest, good usability, and high motivation for further usage for all types of users. However, an apparent resistance to deepen its use continues to be perceived in academia. Based on the research results, weak points of educational gamified systems have been identified, and the main differences and needs in user profiles’ function. With these data, progress regarding implementing this kind of system at the teaching and professional levels must be pursued.

Towards quantitative and intuitive percutaneous tumor puncture via augmented virtual reality.

In recent years, the radiofrequency ablation (RFA) therapy has become a widely accepted minimal invasive treatment for liver tumor patients. However, it is challenging for doctors to precisely and efficiently perform the percutaneous tumor punctures under free-breathing conditions. This is because the traditional RFA is based on the 2D CT Image information, the missing spatial and dynamic information is dependent on surgeons' experience. This paper presents a novel quantitative and intuitive surgical navigation modality for percutaneous respiratory tumor puncture via augmented virtual reality, which is to achieve the augmented visualization of the pre-operative virtual planning information precisely being overlaid on intra-operative surgical scenario. In the pre-operation stage, we first combine the signed distance field of feasible structures (like liver and tumor) where the puncture path can go through and unfeasible structures (like large vessels and ribs) where the needle is not allowed to go through to quantitatively generate the 3D feasible region for percutaneous puncture. Then we design three constraints according to the RFA specialists consensus to automatically determine the optimal puncture trajectory. In the intra-operative stage, we first propose a virtual-real alignment method to precisely superimpose the virtual information on surgical scenario. Then, a user-friendly collaborative holographic interface is designed for real-time 3D respiratory tumor puncture navigation, which can effectively assist surgeons fast and accurately locating the target step-by step. The validation of our system is performed on static abdominal phantom and in vivo beagle dogs with artificial lesion. Experimental results demonstrate that the accuracy of the proposed planning strategy is better than the manual planning sketched by experienced doctors. Besides, the proposed holographic navigation modality can effectively reduce the needle adjustment for precise puncture as well. Our system shows its clinical feasibility to provide the quantitative planning of optimal needle path and intuitive in situ holographic navigation for percutaneous tumor ablation without surgeons' experience-dependence and reduce the times of needle adjustment. The proposed augmented virtual reality navigation system can effectively improve the precision and reliability in percutaneous tumor ablation and has the potential to be used for other surgical navigation tasks.

Laparoscopic Liver Surgery Guided by Virtual Real-time CT-Guided Volume Navigation

BackgroundRecently, virtual navigation system has been applied to hepatic surgery, enabling better visualization of intrahepatic vascular branches and location of tumor. Intraoperative ultrasonography (IOUS) is the most common form of image guidance during liver surgery. However, during laparoscopic hepatectomies (LH), IOUS has several limitations and its reliability has been poorly evaluated. The objective of this work is to evaluate VRCT (virtual real-time CT-guided volume navigation) during LH. This system aims to provide accurate anatomical orientation for surgeons enhancing the safety of LH. MethodsTwenty-seven hepatic neoplasms were resected laparoscopically at our institution under reference guidance of VRCT. During operation, electromagnetic tracking of the surgical instrument was used for navigating the direction of accurate liver transection. ResultsTwenty-six (96.3%) of the 27 lesions (mean diameter 11 mm) were successfully performed under VRCT guidance. Average registration time was < 2 min. Average setup time was approximately 7 min per procedure. VRCT allows the surgeon to navigate liver transection with acceptable accuracy. The mean error was 12 mm. All surgical margins were negative and the mean histologic resection margin was 9 mm. ConclusionsVRCT-guided LH is feasible and provides valuable real-time anatomical feedback during hepatic resections. Advancement of such systems to improve accuracy might greatly compensate for the limitation of laparoscopic IOUS.

Pedestrian Navigation Method Based on Machine Learning and Gait Feature Assistance.

In recent years, as the mechanical structure of humanoid robots increasingly resembles the human form, research on pedestrian navigation technology has become of great significance for the development of humanoid robot navigation systems. To solve the problem that the wearable inertial navigation system based on micro-inertial measurement units (MIMUs) installed on feet cannot effectively realize its positioning function when the body movement is too drastic to be measured correctly by commercial grade inertial sensors, a pedestrian navigation method based on construction of a virtual inertial measurement unit (VIMU) and gait feature assistance is proposed. The inertial data from different positions of pedestrians’ lower limbs are collected synchronously via actual IMUs as training samples. The nonlinear mapping relationship between inertial information from the human foot and leg is established by a visual geometry group-long short term memory (VGG-LSTM) neural network model, based on which the foot VIMU and virtual inertial navigation system (VINS) are constructed. The VINS experimental results show that, combined with zero-velocity update (ZUPT), the integrated method of error modification proposed in this paper can effectively reduce the accumulation of positioning errors in situations where the gait type exceeds the measurement range of the inertial sensors. The positioning performance of the proposed method is more accurate and stable in complex gait types than that merely using ZUPT.

A new application of ultrasound-magnetic resonance multimodal fusion virtual navigation in glioma surgery.

Long-term survival and high-quality life of patients with gliomas depends on the extent of resection (EOR) and the protection of functional white matter fibers. The navigation system provides precise positioning for surgery based on preoperative magnetic resonance imaging (MRI) but the precision decreases when intraoperative brain drift occurs. Ultrasound (US) can support real-time imaging and correct brain shift. The real-time US-MRI multimodal fusion virtual navigation system (UMNS) is a new technique for glioma surgery. In order to obtain a maximum EOR and functional protection, this study aimed to explore the feasibility, efficiency, and safety of real-time UMNS for glioma surgery, and to evaluate the benefit of the new application by UMNS presetting markers between the tumor and functional white matter fiber surgery. A retrospective analysis included 45 patients who underwent glioma surgery, 19 patients with only intraoperative US, and 26 patients with UMNS. A preoperative plan was made by 3D-slicer software based on preoperative MRI. This was combined with a reconstruction of diffusion tensor imaging (DTI) that designed the important locations as "warning points" between functional white matter fibers and tumor. Following patient registration, markers were injected into preset "warning points" under image-guided UMNS in order to give us a warning during surgery in case of postoperative function deficits. The operating time, volumetric assessment in glioma resection, and postoperative complications were evaluated and used to compared those surgeries using intraoperative US (iUS) with those surgeries using intraoperate MRI (iMRI) navigation. A total of 45 patients underwent glioma surgery. Gross total removal (GTR) of iUS alone was achieved in 6 of 19 cases, while this was achieved in 22 of 26 cases with UMNS alone, demonstrating an improvement in rate of GTR from 31.58% to 84.62%, respectively. This may be attributable to the superior US image quality provided by UMNS. In 13 of 26 cases, there was improved image quality (from poor/moderate to moderate/good) with the aid of UMNS. In addition, the consistency of EOR of postoperative MRI evaluated by UMNS (92.31%) was higher than when using iUS alone (42.11%). The whole process of intraoperative scanning time and marker injection did not lead to a significant delay of the operating time compared to using iUS alone, and has been reported to be shorter than with iMRI as well. Furthermore, the percentage of postoperative morbidity in the UMNS group was lower than that in the iUS group (motor deficit: 11.54% vs. 42.11%; aphasia: P =3.85% vs. 31.58%, respectively). Real-time UMNS is an effective, timesaving technology that offers high quality intraoperative imaging. Injection markers between functional white matter fibers and tumor by UMNS can help to obtain a maximum EOR of glioma and functional protection postoperatively. The integration of iUS into the neuronavigation system offered quick and helpful intra-operative images.

Diagnostic Yield of the Virtual Bronchoscopic Navigation System Guided Sampling of Peripheral Lung Lesions using Ultrathin Bronchoscope and Protected Bronchial Brush.

The use of an ultrathin bronchoscope (UB) to diagnose peripheral pulmonary lesions is described. A virtual bronchoscopic navigation system was used to direct the ultrathin scope to the nodule. One of the constraints of this technique was the inability to confirm the target lesion position during biopsy by using a conventional linear endobronchial ultrasound probe, since the probe does not fit into a 1.2 mm working channel of this bronchoscope. The aim of the study was to review our institutional experience with the use of a UB for sampling peripheral pulmonary lesions using the transbronchial brush guided by virtual bronchoscopy. We describe a technique wherein we attempt to brush all the visible bronchial sub-segments once the bronchoscope has reached close to the nodule. In total, 52 patients underwent the procedure between 2010 and 2017. A multiplanar computed tomography (CT) scan of the chest was obtained and subsequently uploaded to the Lung Point Virtual bronchoscopy navigation software. The UB was parked close to the lesion. All visible airway branches were then brushed using a protected bronchial brush. The data were retrospectively abstracted from the electronic medical records using standardized forms. A total of 52 lesions (40 solid, 8 part-solid, 3 cavitary, and 1 ground-glass) were sampled using a transbronchial brush (median, 2; range, 1-8). Twenty-four lesions were under 2 cm in size. The overall success rates were 67.3%. The average diameter of nodules was 2.7±1.01 cm; 65% lesions were in the outer-third of the lungs. The cancer-specific sensitivity was 72.5%. The presence of bronchus sign; location of the lesion; and the characteristics, size, and stage of cancer did not have any impact on the diagnostic yield. Virtual bronchoscopy-guided ultrathin bronchoscopy with bronchial brushing is safe and has a diagnostic yield comparable to other described techniques for evaluating peripheral pulmonary nodules.

Percutaneous Computed Tomography-Guided Lung Biopsies using a Virtual Navigation Guidance: Our Experience

Objective: To evaluate the effectiveness of a virtual CT-guided navigation system (Sirio-MASMEC Biomed) in performing lung biopsies, with greater attention to lesions smaller than 1 cm, compared to the traditional procedure. Methods: This study was approved by the Ethics Committee of our Institute. Two hundred patients were prospectively selected. Of these, 100 were subjected to percutaneous procedure with the use of Sirio and 100 to traditional CT-guided percutaneous procedure. The two methods were compared in terms of absorbed dose, procedure time, complications, and number of non-diagnostic specimens (diagnostic success). Results: Sirio has shown a significant reduction in the absorbed dose and procedure times (p < 0.05), with a lower incidence of complications compared to the traditional procedure. Sirio has also allowed to carry out biopsies of lesions’ diameter ≤10 mm, obtaining fewer non diagnostic specimens thus resulting more effective in terms of diagnostic success. Conclusions: The use of Sirio in sampling biopsy showed a statistically significant reduction in terms of performed scans and procedural time with lower incidence of post-procedural complications compared to the traditional percutaneous procedure, especially for lesions ≤10 mm. The best diagnostic result, the reduction of the dose absorbed and procedural complications makes the procedures more reliable, safety and less invasive. In addition, the reduction of execution time will increase the number of daily interventional procedures improving clinical management.

Developing and Evaluating a Virtual Reality-Based Navigation System for Pre-Sale Housing Sales

Virtual reality (VR) technologies have advanced rapidly in the past few years, and many industries have adopted these cutting-edge technologies for diverse applications to improve their industrial competitiveness. VR has also received considerable recognition in the architecture, engineering, and construction industries, because it can potentially reduce project costs, delivery time, and quality risks, by allowing users to experience unbuilt spaces before breaking ground, resolving construction conflicts virtually, and reviewing complex details in immersive environments. In the real estate market, VR can also play an important role in affecting buyers’ housing purchasing decisions, especially for housing markets in Asia, where the pre-sale system is extremely common. Applying VR to the pre-sale housing system is promising, because the concept of pre-sale refers to a strategy adopted by developers that sell housing through agreements on residential units that have not been constructed yet, and VR at this stage could be a useful tool for visual communication in a true-to-scale environment. However, does VR really benefit sales in the housing market? Can clients accept using VR, instead of using traditional materials (i.e., paper-based images and physical models), to navigate and experience housing projects? The objective of this study is to develop a VR-based navigation system for a pre-sale housing project in Taiwan. We invited 30 potential clients to test the system and explore the implications of using it for project navigation. The results reveal that VR enhances the understandings of a project (perceived usefulness) and increases clients’ intention to purchase, while the operation of VR (perceived ease-of-use) is still the major challenge to affect clients’ satisfaction and the developer’s acceptance with respect to applying it to future housing sales.

Percutaneous bone biopsy using a flat-panel cone beam computed tomography virtual navigation system.

ObjectivesTo assess the clinical role of flat-panel cone beam CT (CBCT) in performing percutaneous needle biopsy (PNB) of bone lesions. Flat-panel cone beam CT systems have been used as a guidance tool for performing percutaneous biopsy. Real-time fluoroscopy and virtual navigation systems help simplify needle path planning and shorten procedure times.MethodsFrom March 2012 to March 2016, 80 patients with 80 bone lesions were retrospectively enrolled in the study in Zhengzhou city of China. Technical success, diagnostic accuracy, puncture performance, procedure time, complications, and effective radiation exposure were calculated.ResultsAll biopsies were technically successful (100%). Sufficient tissue for histopathological analysis was obtained in 75 of 80 cases. The sensitivity of PNB of bone lesions was 95.5%, the specificity was 83.3%, and accuracy was 93.7%. The mean scoring of puncture performance was 3.9 ± 1.3. The mean total procedure time was 13.20 ± 4.4 min, resulting in a mean exposure dose of 11.3 ± 5.1 mSv. The complication rate was 8.7%.ConclusionPercutaneous bone biopsy using CBCT is a safe and effective method that simplifies needle path planning and shortens procedure times.