3D Patient-Specific Virtual Models for Presurgical Planning in Patients with Recto-Sigmoid Endometriosis Nodules: A Pilot Study

Background and Objective: In recent years, 3D printing has been used to support surgical planning or to guide intraoperative procedures in various surgical specialties. An improvement in surgical planning for recto-sigmoid endometriosis (RSE) excision might reduce the high complication rate related to this challenging surgery. The aim of this study was to build novel presurgical 3D models of RSE nodules from magnetic resonance imaging (MRI) and compare them with intraoperative findings. Materials and Methods: A single-center, observational, prospective, cohort, pilot study was performed by enrolling consecutive symptomatic women scheduled for minimally invasive surgery for RSE between November 2019 and June 2020 at our institution. Preoperative MRI were used for building 3D models of RSE nodules and surrounding pelvic organs. 3D models were examined during multi-disciplinary preoperative planning, focusing especially on three domains: degree of bowel stenosis, nodule’s circumferential extension, and bowel angulation induced by the RSE nodule. After surgery, the surgeon was asked to subjectively evaluate the correlation of the 3D model with the intra-operative findings and to express his evaluation as “no correlation”, “low correlation”, or “high correlation” referring to the three described domains. Results: seven women were enrolled and 3D anatomical virtual models of RSE nodules and surrounding pelvic organs were generated. In all cases, surgeons reported a subjective “high correlation” with the surgical findings. Conclusion: Presurgical 3D models could be a feasible and useful tool to support surgical planning in women with recto-sigmoidal endometriotic involvement, appearing closely related to intraoperative findings.

Augmented Reality to Assist Skin Paddle Harvesting in Osteomyocutaneous Fibular Flap Reconstructive Surgery: A Pilot Evaluation on a 3D-Printed Leg Phantom

BackgroundAugmented Reality (AR) represents an evolution of navigation-assisted surgery, providing surgeons with a virtual aid contextually merged with the real surgical field. We recently reported a case series of AR-assisted fibular flap harvesting for mandibular reconstruction. However, the registration accuracy between the real and the virtual content needs to be systematically evaluated before widely promoting this tool in clinical practice. In this paper, after description of the AR based protocol implemented for both tablet and HoloLens 2 smart glasses, we evaluated in a first test session the achievable registration accuracy with the two display solutions, and in a second test session the success rate in executing the AR-guided skin paddle incision task on a 3D printed leg phantom.MethodsFrom a real computed tomography dataset, 3D virtual models of a human leg, including fibula, arteries and skin with planned paddle profile for harvesting, were obtained. All virtual models were imported into Unity software to develop a marker-less AR application suitable to be used both via tablet and via HoloLens 2 headset. The registration accuracy for both solutions was verified on a 3D printed leg phantom obtained from the virtual models, by repeatedly applying the tracking function and computing pose deviations between the AR-projected virtual skin paddle profile and the real one transferred to the phantom via a CAD/CAM cutting guide. The success rate in completing the AR-guided task of skin paddle harvesting was evaluated using CAD/CAM templates positioned on the phantom model surface.ResultsOn average, the marker-less AR protocol showed comparable registration errors (ranging within 1-5 mm) for tablet-based and HoloLens-based solution. Registration accuracy seems to be quite sensitive to ambient light conditions. We found a good success rate in completing the AR-guided task within an error margin of 4 mm (97% and 100% for tablet and HoloLens, respectively). All subjects reported greater usability and ergonomics for HoloLens 2 solution.ConclusionsResults revealed that the proposed marker-less AR based protocol may guarantee a registration error within 1-5 mm for assisting skin paddle harvesting in the clinical setting. Optimal lightening conditions and further improvement of marker-less tracking technologies have the potential to increase the efficiency and precision of this AR-assisted reconstructive surgery.

Software Details in Occlusal Splint Creation through 3Shape Design Studio

Introduction: Occlusal splints are usually the first choice in the treatment of bruxism. Splints can also be the only treatment or can be ended with adhesive restoration, orthodontic or prosthetic treatment. Methods: This article demonstrates the steps of a digital workflow through the 3Shape Design system - splint studio. The initial units are virtual models, scanned by Trios Color Scanner (3Shape). Results: The digital protocol includes eight steps that allow precise and detailed creation of the searched object. Each step is described from the perspective of a clinician, prosthetist and orthodontist, not a dental technician. Possible complications and ways to management with them are described. Conclusion: Digital protocol of occlusal splint creation gives many opportunities according to design, thickness and occlusion.

USE OF CYBER–PHYSICAL SYSTEMS FOR THE KEY ROLES OF QUANTITY SURVEYORS

Cyber–physical systems (CPS) enable the synergistic integration of virtual models with the physical environment. CPS are being increasingly recognized because of their ability to improve information management in construction projects, make project delivery efficient, and enhance facilities management. The use of virtual models in the construction industry is growing. A quantity surveyor (QS) is responsible for estimating and monitoring construction costs from project inception to completion. The use of CPS could integrate the physical environment with the digital information available to QSs. Hence CPS has the potential to streamline the workflow related to key roles of QSs. Thus, the aim of the study was to evaluate the ability of CPS to facilitate the key roles expected of a QS. The study used a qualitative approach, consisting of 18 semi-structured interviews. The interview findings were analysed using manual content analysis. The literature review revealed the need for CPS in the construction industry and identified the key roles of QSs. The interviewees identified the existing CPS and their supportive applications, technologies and proposed new systems. The study findings provide insights on the reforms required in the key roles of QSs when using CPS.

Modelling the ZalaZONE Proving Ground: a benchmark of State-of-the-art Automotive Simulators PreScan, IPG CarMaker, and VTD Vires

In our days, simulation based development is a core element of vehicle engineering, especially considering highly automated or fully autonomous vehicles. Accordingly, the paper presents a benchmark of three different automotive simulators: PreScan, IPG CarMaker, and VTD Vires. The three software tools were applied for the same goal, namely, modelling the ZalaZONE Proving Ground of Hungary for vehicle testing. The paper aims to highlight the experiences while creating the virtual models by presenting and comparing the relevant software features and providing suggestions for scientific or practical application.

Virtual occlusal record: a literature review about the digital method

To produce prostheses through the digital flow, it is essential to transfer the correct patient’s interocclusal relationship to the digital software program, enabling the articulation of virtual models. Therefore, the aim of this study was to carry out a narrative literature review to describe and discuss aspects related to the virtual occlusal record realization, as well as its precision and accuracy in different clinical situations. Searches for scientific publications were performed in different databases and only articles in English related to the topic were selected. Different methods for the alignment of virtual models are described in the literature, the main one being the scanning of the patient in occlusion, usually in a position of maximum intercuspation. However, this technique may demonstrate disagreement with the patient's actual occlusal relationship due to several factors, and therefore studies were carried out to verify the precision and accuracy of these records. Most studies use plaster models and industrial scanner to capture the record, with few studies performed with intraoral scanner in patients. Despite the various scanner systems available and the different ways of evaluating them, in general, the studies show an adequate precision and accuracy of virtual occlusal records of dentate models. However, the absence of dental elements is related to the lower accuracy of these records, it being necessary to establish an appropriate method of scanning for these clinical situations.

Navigation of Frameless Fixation for Gammaknife Radiosurgery Using Fixed Augmented Reality

Augmented reality (AR) offers a new medical treatment approach. We aimed to evaluate frameless fixation navigation using a 3D-printed patient model with fixed-AR technology for gammaknife radiosurgery. Fixed-AR navigation was developed using the inside-out method with visual inertial odometry algorithms, and the flexible Quick Response (QR) marker was created for object-feature recognition. Virtual 3D-patient models for AR-rendering were created via 3D-scanning utilizing TrueDepth and cone-beam computed tomography (CBCT) to generate a new GammaKnife IconTM model. A 3D-printed patient model included fiducial markers, and virtual 3D-patient models were used to validate registration accuracy. Registration accuracy between initial frameless fixation and re-fixation navigated fixed-AR was validated through visualization. The quantitative method was validated through set-up errors, fiducial marker coordinates, and high-definition motion management (HDMM) values. 3D-printed models and virtual models were correctly overlapped under frameless fixation. Virtual models from both 3D-scanning and CBCT were enough to tolerate the navigated frameless re-fixation. Although the CBCT virtual model consistently delivered more accurate results, 3D-scanning was sufficient. Frameless re-fixation accuracy navigated in virtual models had mean set-up errors within 1 mm and 1.5° in all axes. Mean fiducial marker differences from coordinates in virtual models were within 2.5 mm in all axes, and mean 3D errors were within 3 mm. Mean HDMM difference values in virtual models were within 1.5 mm of initial HDMM values. The variability from navigation fixed-AR is enough to consider repositioning frameless fixation without CBCT scanning for treating patients fractionated with large multiple metastases lesions (>3 cm) who have difficulty enduring long beam-on time. This system could be applied to novel radiosurgery navigation for frameless fixation with reduced preparation time.

Virtual Control Object for Siemens Logic Controllers and Online PLC Education

This paper deals with the possibility of creating virtual C # models connectable to a virtual PLC of Siemens. The models will lead to the improvement and simplification of the online PLC education. Hardware solutions cost a lot of money, while using a software version of PLC leads to cheaper simulations. Paper presents the design and implementation of the virtual models, including the ways of the interconnection with PLCSIM, visualization and finally demonstration for the selected virtual model.