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

2022 ◽  
Vol 11 ◽  
Author(s):  
Laura Cercenelli ◽  
Federico Babini ◽  
Giovanni Badiali ◽  
Salvatore Battaglia ◽  
Achille Tarsitano ◽  
...  
Keyword(s):  
Augmented Reality ◽  
Success Rate ◽  
Test Session ◽  
Registration Accuracy ◽  
Skin Paddle ◽  
The Real ◽  
Virtual Models ◽  
Cad Cam ◽  
3D Printed ◽  
Fibular Flap

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.

scholarly journals Navigation of Frameless Fixation for Gammaknife Radiosurgery Using Fixed Augmented Reality

2021 ◽  
Author(s):  
Hyeong Cheol Moon ◽  
Sang Joon Park ◽  
Youngdeok Kim ◽  
Kyung Min Kim ◽  
Ho Kang ◽  
...  
Keyword(s):  
Augmented Reality ◽  
3D Scanning ◽  
Fiducial Marker ◽  
High Definition ◽  
Registration Accuracy ◽  
Motion Management ◽  
Virtual Models ◽  
Patient Model ◽  
3D Printed ◽  
Set Up

Abstract 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.

scholarly journals Development of an inside-out augmented reality technique for neurosurgical navigation

2021 ◽  
Vol 51 (2) ◽  
pp. E21
Author(s):  
Yun-Sik Dho ◽  
Sang Joon Park ◽  
Haneul Choi ◽  
Youngdeok Kim ◽  
Hyeong Cheol Moon ◽  
...  
Keyword(s):  
Augmented Reality ◽  
Navigation System ◽  
Fine Tuning ◽  
Image Feature ◽  
Patient Specific ◽  
Registration Accuracy ◽  
Pilot Model ◽  
Patient Model ◽  
3D Printed ◽  
Inside Out

OBJECTIVE With the advancement of 3D modeling techniques and visualization devices, augmented reality (AR)–based navigation (AR navigation) is being developed actively. The authors developed a pilot model of their newly developed inside-out tracking AR navigation system. METHODS The inside-out AR navigation technique was developed based on the visual inertial odometry (VIO) algorithm. The Quick Response (QR) marker was created and used for the image feature–detection algorithm. Inside-out AR navigation works through the steps of visualization device recognition, marker recognition, AR implementation, and registration within the running environment. A virtual 3D patient model for AR rendering and a 3D-printed patient model for validating registration accuracy were created. Inside-out tracking was used for the registration. The registration accuracy was validated by using intuitive, visualization, and quantitative methods for identifying coordinates by matching errors. Fine-tuning and opacity-adjustment functions were developed. RESULTS ARKit-based inside-out AR navigation was developed. The fiducial marker of the AR model and those of the 3D-printed patient model were correctly overlapped at all locations without errors. The tumor and anatomical structures of AR navigation and the tumors and structures placed in the intracranial space of the 3D-printed patient model precisely overlapped. The registration accuracy was quantified using coordinates, and the average moving errors of the x-axis and y-axis were 0.52 ± 0.35 and 0.05 ± 0.16 mm, respectively. The gradients from the x-axis and y-axis were 0.35° and 1.02°, respectively. Application of the fine-tuning and opacity-adjustment functions was proven by the videos. CONCLUSIONS The authors developed a novel inside-out tracking–based AR navigation system and validated its registration accuracy. This technical system could be applied in the novel navigation system for patient-specific neurosurgery.

Real-world environment affects the color appearance of virtual stimuli produced by augmented reality

2019 ◽  
Vol 2019 (1) ◽  
pp. 237-242
Author(s):  
Siyuan Chen ◽  
Minchen Wei
Keyword(s):  
Augmented Reality ◽  
Real World ◽  
Mixed Reality ◽  
Rapid Development ◽  
Light Level ◽  
Color Appearance ◽  
Chromatic Adaptation ◽  
Lighting Condition ◽  
The Real ◽  
World Environment

Color appearance models have been extensively studied for characterizing and predicting the perceived color appearance of physical color stimuli under different viewing conditions. These stimuli are either surface colors reflecting illumination or self-luminous emitting radiations. With the rapid development of augmented reality (AR) and mixed reality (MR), it is critically important to understand how the color appearance of the objects that are produced by AR and MR are perceived, especially when these objects are overlaid on the real world. In this study, nine lighting conditions, with different correlated color temperature (CCT) levels and light levels, were created in a real-world environment. Under each lighting condition, human observers adjusted the color appearance of a virtual stimulus, which was overlaid on a real-world luminous environment, until it appeared the whitest. It was found that the CCT and light level of the real-world environment significantly affected the color appearance of the white stimulus, especially when the light level was high. Moreover, a lower degree of chromatic adaptation was found for viewing the virtual stimulus that was overlaid on the real world.

scholarly journals Laparoscopic augmented reality registration for oncological resection site repair

2021 ◽  
Author(s):  
Fabian Joeres ◽  
Tonia Mielke ◽  
Christian Hansen
Keyword(s):  
Augmented Reality ◽  
Time Pressure ◽  
Tumour Resection ◽  
Anatomical Landmarks ◽  
Proof Of Concept ◽  
Registration Accuracy ◽  
Target Registration Error ◽  
Concept Evaluation ◽  
Navigation Support ◽  
Challenges And Opportunities

Abstract Purpose Resection site repair during laparoscopic oncological surgery (e.g. laparoscopic partial nephrectomy) poses some unique challenges and opportunities for augmented reality (AR) navigation support. This work introduces an AR registration workflow that addresses the time pressure that is present during resection site repair. Methods We propose a two-step registration process: the AR content is registered as accurately as possible prior to the tumour resection (the primary registration). This accurate registration is used to apply artificial fiducials to the physical organ and the virtual model. After the resection, these fiducials can be used for rapid re-registration (the secondary registration). We tested this pipeline in a simulated-use study with $$N=18$$ N = 18 participants. We compared the registration accuracy and speed for our method and for landmark-based registration as a reference. Results Acquisition of and, thereby, registration with the artificial fiducials were significantly faster than the initial use of anatomical landmarks. Our method also had a trend to be more accurate in cases in which the primary registration was successful. The accuracy loss between the elaborate primary registration and the rapid secondary registration could be quantified with a mean target registration error increase of 2.35 mm. Conclusion This work introduces a registration pipeline for AR navigation support during laparoscopic resection site repair and provides a successful proof-of-concept evaluation thereof. Our results indicate that the concept is better suited than landmark-based registration during this phase, but further work is required to demonstrate clinical suitability and applicability.

scholarly journals Revealing Hidden Local Cultural Heritage through a Serious Escape Game in Outdoor Settings

Information ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 10
Author(s):  
Stavroula Tzima ◽  
Georgios Styliaras ◽  
Athanasios Bassounas
Keyword(s):  
Virtual Reality ◽  
Augmented Reality ◽  
Cultural Heritage ◽  
Physical Environment ◽  
Local History ◽  
Educational Context ◽  
Virtual Reality Technology ◽  
The Real ◽  
Hybrid Type ◽  
Game Mechanics

Escape Rooms are presently considered a very popular social entertainment activity, with increasing popularity in education field, since they are considered capable of stimulating the interest of players/students and enhancing learning. The combined game mechanics have led to blended forms of Escape Rooms, the Serious Escape Games (SEGs) and the hybrid type of Escape Rooms that uses Augmented Reality (AR)/Virtual Reality technology, a type that is expected to be widely used in the future. In the current study, the MillSecret is presented, a multi-player Serious Escape Game about local cultural heritage, where the players must solve a riddle about the cultural asset of watermills. MillSecret uses AR technology and it was designed to be conducted in the real-physical environment and in an informal educational context. The paper describes the game, its implementation, the playing process, and its evaluation, which aimed to study the feasibility of game conduction in outdoor settings and the views and experience of players with the game, the local cultural heritage and local history. Evaluation results reveal, among other findings, a very positive first feedback from players that allows us to further evolve the development of the game.

scholarly journals Hybrid Spine Simulator Prototype for X-ray Free Pedicle Screws Fixation Training

2021 ◽  
Vol 11 (3) ◽  
pp. 1038
Author(s):  
Sara Condino ◽  
Giuseppe Turini ◽  
Virginia Mamone ◽  
Paolo Domenico Parchi ◽  
Vincenzo Ferrari
Keyword(s):  
Augmented Reality ◽  
Low Cost ◽  
Lumbar Vertebrae ◽  
Pedicle Screws ◽  
Simulation Software ◽  
Patient Specific ◽  
Innovative Strategy ◽  
X Ray ◽  
3D Printed ◽  
Harmful Radiation

Simulation for surgical training is increasingly being considered a valuable addition to traditional teaching methods. 3D-printed physical simulators can be used for preoperative planning and rehearsal in spine surgery to improve surgical workflows and postoperative patient outcomes. This paper proposes an innovative strategy to build a hybrid simulation platform for training of pedicle screws fixation: the proposed method combines 3D-printed patient-specific spine models with augmented reality functionalities and virtual X-ray visualization, thus avoiding any exposure to harmful radiation during the simulation. Software functionalities are implemented by using a low-cost tracking strategy based on fiducial marker detection. Quantitative tests demonstrate the accuracy of the method to track the vertebral model and surgical tools, and to coherently visualize them in either the augmented reality or virtual fluoroscopic modalities. The obtained results encourage further research and clinical validation towards the use of the simulator as an effective tool for training in pedicle screws insertion in lumbar vertebrae.

RTR AR Photo Booth: The Real-Time Rendering Augmented Reality Photo Booth

2021 ◽  
Author(s):  
Muhamad Fajar ◽  
Yogi Udjaja ◽  
Eko Setyo Purwanto ◽  
Anderies
Keyword(s):  
Augmented Reality ◽  
Real Time ◽  
The Real

Augmented Reality Berbasis Android Sebagai Media Pembelajaran Sistem Tata Surya

2021 ◽  
Vol 2 (1) ◽  
pp. 53-59
Author(s):  
Yulia Fatma ◽  
Armen Salim ◽  
Regiolina Hayami
Keyword(s):  
Augmented Reality ◽  
Solar System ◽  
Real Time ◽  
Real World ◽  
Virtual World ◽  
The Real ◽  
Virtual Objects ◽  
Augmented Reality Technology ◽  
The Revolution

Along with the development, the application can be used as a medium for learning. Augmented Reality is a technology that combines two-dimensional’s virtual objects and three-dimensional’s virtual objects into a real three-dimensional’s  then projecting the virtual objects in real time and simultaneously. The introduction of Solar System’s material, students are invited to get to know the planets which are directly encourage students to imagine circumtances in the Solar System. Explenational of planets form and how the planets make the revolution and rotation in books are considered less material’s explanation because its only display objects in 2D. In addition, students can not practice directly in preparing the layout of the planets in the Solar System. By applying Augmented Reality Technology, information’s learning delivery can be clarified, because in these applications are combined the real world and the virtual world. Not only display the material, the application also display images of planets in 3D animation’s objects with audio.

COMPUTER SIMULATION OF A SINGLE-PHASE ASYNCHRONOUS MOTOR

2020 ◽  
pp. 29-35
Author(s):  
S.Yu. Trudnev ◽  
Keyword(s):  
Computer Simulation ◽  
Single Phase ◽  
Asynchronous Motor ◽  
Computer Models ◽  
Virtual Model ◽  
Modes Of Operation ◽  
The Real ◽  
Matlab Program ◽  
Virtual Models ◽  
Asynchronous Motors

The most widely used single-phase asynchronous motors are described and also substitution and vector dia-grams are reviewed. Theoretical and mathematical descriptions of processes of controlling and enabling asynchronous modes of operation were provided, on the basis of which computer models of a single-phase asynchronous motor in static and dynamic modes was created in the Matlab program. Experiments were per-formed on the real and virtual models, and the data obtained were processed and compared to confirm the adequacy of the developed virtual model.

scholarly journals Registration Error Analysis for Augmented Reality

1997 ◽  
Vol 6 (4) ◽  
pp. 413-432 ◽  
Author(s):  
Richard L. Holloway
Keyword(s):  
Augmented Reality ◽  
Error Analysis ◽  
Optical Distortion ◽  
Calibration Error ◽  
Head Tracking ◽  
System Delay ◽  
System Calibration ◽  
The Real ◽  
Registration Error ◽  
Real Environment

Augmented reality (AR) systems typically use see-through head-mounted displays (STHMDs) to superimpose images of computer-generated objects onto the user's view of the real environment in order to augment it with additional information. The main failing of current AR systems is that the virtual objects displayed in the STHMD appear in the wrong position relative to the real environment. This registration error has many causes: system delay, tracker error, calibration error, optical distortion, and misalignment of the model, to name only a few. Although some work has been done in the area of system calibration and error correction, very little work has been done on characterizing the nature and sensitivity of the errors that cause misregistration in AR systems. This paper presents the main results of an end-to-end error analysis of an optical STHMD-based tool for surgery planning. The analysis was done with a mathematical model of the system and the main results were checked by taking measurements on a real system under controlled circumstances. The model makes it possible to analyze the sensitivity of the system-registration error to errors in each part of the system. The major results of the analysis are: (1) Even for moderate head velocities, system delay causes more registration error than all other sources combined; (2) eye tracking is probably not necessary; (3) tracker error is a significant problem both in head tracking and in system calibration; (4) the World (or reference) coordinate system adds error and should be omitted when possible; (5) computational correction of optical distortion may introduce more delay-induced registration error than the distortion error it corrects, and (6) there are many small error sources that will make submillimeter registration almost impossible in an optical STHMD system without feedback. Although this model was developed for optical STHMDs for surgical planning, many of the results apply to other HMDs as well.

Sign in / Sign up

Export Citation Format

Share Document