Brain organoids for hypoxic-ischemic studies: from bench to bedside.

Our current knowledge regarding the development of the human brain mostly derives from experimental studies on non-human primates, sheep, and rodents. However, these studies may not completely simulate all the features of human brain development as a result of species differences and variations in pre- and postnatal brain maturation. Therefore, it is important to supplement the in vivo animal models to increase the possibility that preclinical studies have appropriate relevance for potential future human trials. Three-dimensional brain organoid culture technology could complement in vivo animal studies to enhance the translatability of the preclinical animal studies and the understanding of brain-related disorders. In this review, we focus on the development of a model of hypoxic-ischemic (HI) brain injury using human brain organoids to complement the translation from animal experiments to human pathophysiology. We also discuss how the development of these tools provides potential opportunities to study fundamental aspects of the pathophysiology of HI-related brain injury including differences in the responses between males and females.

Laser Scanner-Based Hyperboloid Cooling Tower Geometry Inspection: Thickness and Deformation Mapping.

Hyperboloid cooling towers are counted among the largest cast-in-place industrial structures. They are an essential element of cooling systems used in many power plants in service today. Their main structural component, a reinforced-concrete shell in the form of a one-sheet hyperboloid with bidirectional curvature continuity, makes them stand out against other towers and poses very high construction and service requirements. The safe service and adequate durability of the hyperboloid structure are guaranteed by the proper geometric parameters of the reinforced-concrete shell and monitoring of their condition over time. This article presents an original concept for employing terrestrial laser scanning to conduct an end-to-end assessment of the geometric condition of a hyperboloid cooling tower as required by industry standards. The novelty of the proposed solution lies in the use of measurements of the interior of the structure to determine the actual thickness of the hyperboloid shell, which is generally disregarded in geometric measurements of such objects. The proposal involves several strategies and procedures for a reliable verification of the structure's verticality, the detection of signs of ovalisation of the shell, the estimation of the parameters of the structure's theoretical model, and the analysis of the distribution of the thickness and geometric imperfections of the reinforced-concrete shell. The idea behind the method for determining the actual thickness of the shell (including its variation due to repairs and reinforcement operations), which is generally disregarded when measuring the geometry of such structures, is to estimate the distance between point clouds of the internal and external surfaces of the structure using the M3C2 algorithm principle. As a particularly dangerous geometric anomaly of hyperboloid cooling towers, shell ovalisation is detected with an innovative analysis of the bimodality of the frequency distribution of radial deviations in horizontal cross-sections. The concept of a complete assessment of the geometry of a hyperboloid cooling tower was devised and validated using three measurement series of a structure that has been continuously in service for fifty years. The results are consistent with data found in design and service documents. We identified a permanent tilt of the structure's axis to the northeast and geometric imperfections of the hyperboloid shell from -0.125 m to +0.136 m. The results also demonstrated no advancing deformation of the hyperboloid shell over a two-year research period, which is vital for its further use.

Three-dimensional technologies in chest wall resection and reconstruction.

Resection and reconstruction of the chest wall can pose unique challenges given its vital role in the protection of the thoracic viscera and the dynamic part it plays in respiration. A number of new three-dimensional (3D) technologies may be invaluable in tackling these challenges. Herein we review the use of 3D technologies in preoperative imaging with virtual 3D models, printing of 3D models for preoperative planning, and printing of 3D prostheses when approaching complex chest wall reconstruction.

Perception and knowledge of learners about the use of 3D technologies in manual therapy education - a qualitative study.

OBJECTIVES: Manual therapy is a specific hands-on approach used and taught by various professions such as physiotherapy and osteopathy. The current paradigm of teaching manual therapy incorporates the traditional 'See one, do one, teach one' approach. However, this 'teacher centred' approach may not enable learners to develop the complex clinical skills of manual therapy. In this context, 3D technologies such as virtual reality may facilitate the teaching and learning of manual therapy. Hence the aim of the current study was to investigate the perception, knowledge and attitude of manual therapy learners about the use of 3D technologies in manual therapy education. METHODS: An exploratory qualitative research design using semi-structured interviews was used in this study. A total of ten manual therapy (5 physiotherapy and 5 osteopathic) students (mean age = 32; 80% female) enrolled in an appropriate physiotherapy or osteopathic degree provided by a New Zealand recognized institution (e.g., university or polytechnic) participated in this study. Data saturation was achieved after 10 interviews (average duration: 35 min) that provided thick data. A thematic analysis was used for data analysis. RESULTS: Six factors were identified which appeared to influence participants' perception of role of technology in manual therapy education. These were (1) the sufficiency of current teaching method; (2) evolution as a learner (a novice to an expert); (3) need for objectivity; (4) tutor feedback; (5) knowledge and (6) barriers and enablers. These six factors influenced the participants' perception about the role of 3D technologies in manual therapy education with participants evidently taking two distinct/polarized positions ('no role' (techstatic) versus a 'complete role' (techsavvy)). CONCLUSION: Although 3D technology may not replace face-to-face teaching, it may be used to complement the traditional approach of learning/teaching to facilitate the learning of complex skills according to the perceptions of manual therapy learners in our study. The advantage of such an approach is an area of future research.

Views on Augmented Reality, Virtual Reality, and 3D Printing in Modern Medicine and Education: A Qualitative Exploration of Expert Opinion.

Although an increased usage and development of 3D technologies is observed in healthcare over the last decades, full integration of these technologies remains challenging. The goal of this project is to qualitatively explore challenges, pearls, and pitfalls of AR/VR/3D printing applications usage in the medical field of a university medical center. Two rounds of face-to-face interviews were conducted using a semi-structured protocol. First an explorative round was held, interviewing medical specialists (8), PhD students (7), 3D technology specialists (5), and university teachers (3). In the second round, twenty employees in high executive functions of relevant departments were interviewed on seven statements that resulted from the first interviewing round. Data analysis was performed using direct content analyses. The first interviewing round resulted in challenges and opportunities in 3D technology usage that were grouped in 5 themes: aims of using AR/VR/3D printing (1), data acquisition (2), data management plans (3), software packages and segmentation tools (4), and output data and reaching end-user (5). The second interviewing round resulted in an overview of ideas and insights on centralization of knowledge, improving implementation of 3D technology in daily healthcare, reimbursement of 3D technologies, recommendations for further studies, and requirement of using certified software. An overview of challenges and opportunities of 3D technologies in healthcare was provided. Well-designed studies on clinical effectiveness, implementation and cost-effectiveness are warranted for further implementation into the clinical setting.

Fully Digitalized Workflow for One-Stage Mandibular Contouring and Orthognathic Surgery to Correct Severe Facial Asymmetry.

INTRODUCTION: Surgical correction of facial asymmetry is commonly performed in at least two stages. Recently, because of the long duration of a two-step procedure, the demand for a one-step procedure has increased. Our study aims to present a fully digitalized workflow for one-stage mandibular contouring (MC) and bimaxillary surgery to correct severe facial asymmetry using 3D technology. MATERIALS AND METHODS: A retrospective monocentric study was conducted for all patients affected by severe facial asymmetry who had undergone MC and orthognathic surgery between January 2018 and June 2020 at the Face Surgery Center, in Parma, Italy. RESULTS: The final study sample included 20 patients (12 women and 8 men). The mean age of the patients at the time of surgery was 20.8 years (range: 18-25 years). At the one-year follow-up, all patients had stable occlusion with a symmetric face. Mandibular angle degree (Ar-Go-Me) increased significantly from 113. 6° to 122.7° at the left side and from 113.3° to 122.7° at the right side (p < 0.05) (Table 1). The mandibular width (Go-Go) decreased from 116.5 to 106.4 mm (p < 0.05). CONCLUSION: A fully digitalized workflow for one-stage MC and bimaxillary surgery is a safe and valid option to correct facial asymmetry. CAD CAM technology is an indispensable tool to obtain predictable results. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Evaluating the morphological and metric sex of human crania using 3-dimensional (3D) technology.

Identifying the skeletal remains of an unidentified individual is a priority for the medico-legal system because identification increases the chances of finding the person responsible and provides closure to the family. The purpose of this research was to develop a combined morphological and metric cranial sex assessment method using 3D technology that accommodates the medico-legal system, and their use of 3D models facilitates the technological transition to digitally archived skeletal collections. A total of 91 individuals of European biogeographical ancestry from the William M. Bass Donated Skeletal Collection (University of Tennessee Knoxville) were imaged using photogrammetry, turned into 3D models using Agisoft PhotoScan, and digitally evaluated using 3D Studio Max. This novel method digitally evaluated five cranial traits, including the nasal aperture height, nasal aperture width, mastoid length, the general size and architecture, and the supraorbital ridges, combining techniques that can only be done digitally with those that can be completed on the actual bone. Preliminary statistical tests demonstrate an overall accuracy rate of 90% when tested against the training sample (20 males, 20 females) and 75% when tested against the test sample (51 individuals). Although no intra- or inter-observer error rate tests were done, and further testing on other skeletal collections is necessary, this method allows forensic anthropologists to perform relatively easy point-to-point measurements, the quantification of traditionally non-quantified traits, the possibility of reproducible results, and the ability for future analyses or research.

Laparoscopic Appendectomy Performed by junior SUrgeonS: impact of 3D visualization on surgical outcome. Randomized multicentre clinical trial. (LAPSUS TRIAL).

BACKGROUND: The purpose of this study was to evaluate the effect of 3D visualization applied to laparoscopic appendectomy (LA) performed by young surgeons (YS). We considered both operative features and clinical outcomes, aiming to highlight the benefits that this technology could bring to novice surgeons and their laparoscopic training. METHODS: All the surgical procedures were performed by residents who had performed less than 20 appendectomies prior to the beginning of the study under the supervision of an expert surgeon. At the time of enrolment patients were randomized into two arms: Experimental arm (EA): laparoscopic appendectomy performed with laparoscopic 3D vision technology. Control arm (CA): laparoscopic appendectomy performed with the "standard" 2D technology. The primary endpoint was to find any statistically significant difference in operative time between the two arms. Differences in conversion rate, intra-operative complications, post-operative complications and surgeons' operative comfort were considered as secondary endpoints. RESULTS: We randomized 135 patients into the two study arms. The two groups were homogeneous for demographic characteristics, BMI and ASA scores. The characteristics of clinical presentation and anatomical position showed no significant difference. The operative time was longer in the CA (57.5 vs. 49.6 min, p = 0.048, 95% CI). In the subgroup of complicated appendicitis, this trend toward inferior operative time was confirmed without reaching statistical significance (2D = 60 min, 3D = 49.5 min, p = 0.082 95% CI). No intra-operative complications were observed in either group. The conversion rate was 5.6% (4 patients) in the 2D group and 4.6% (3 patients) in 3D group. CONCLUSION: The utilization of 3D laparoscopy was associated with reduction in operative time without influencing other parameters, in particular without altering the safety profile of the procedure.

Sinus Venosus ASDs: Imaging and Percutaneous Closure.

PURPOSE OF THE REVIEW: Percutaneous closure of sinus venosus atrial septal defects (ASD) using covered stent implantation is a new and promising minimally invasive technique. New imaging tools are used to ensure preoperative anatomical characterization and preoperative guidance, which are key procedural success factors. Here we will describe and analyze these recent developments. RECENT FINDINGS: Sinus venosus ASDs present a wide variety of anatomical features which must be described and analyzed using various imaging tools, including 3D technology. Percutaneous closure is challenging, but can hasten clinical recovery compared to the gold-standard conventional open-heart surgery. The feasibility of percutaneous closure relies on precise preoperative anatomical study and on real-time guidance using a multimodal fusion imaging process. Three-dimensional modeling of sinus venosus ASD is essential to understand the large anatomical panel encountered in this pathology. Multimodal fusion imaging guidance is very useful for performing sinus venosus ASD percutaneous closure in selected patients.

Pressure Membrane FBG Sensor Realized by 3D Technology.

The publication describes the design, production, and practical verification of an alternative pressure sensor suitable for measuring the pressure of gas, based on a combination of fiber-optic technology and 3D printing methods. The created sensor uses FBG (Fiber Bragg Grating) suitably implemented on a movable membrane. The sensor is equipped with a reference FBG to compensate for the effect of ambient temperature on the pressure measurement. The sensor is characterized by its immunity to EM interference, electrical passivity at the measuring point, small size, and resistance to moisture and corrosion. The FBG pressure sensor has a pressure sensitivity of 9.086 pm/mbar in the range from 0 to 9 mbar with a correlation coefficient of 0.9982. The pressure measurement in the specified range shows an average measurement error of 0.049 mbar and a reproducibility parameter of 0.0269 ± 0.0135 mbar.

3D Printed Surgical Guides Applied in Rhinoplasty to Help Obtain Ideal Nasal Profile.

INTRODUCTION: As computer simulation for rhinoplasty continues to rise, the technology's utility extends beyond increasing patient conversion. Virtual simulation of the surgical result can assist with surgical planning and intraoperative decision-making. 3D printed anatomic models or surgical guides based on 3D images may help align surgeons with their original surgical plan. This study aims to evaluate the utility of 3D printed surgical guides as an intraoperative tool to help establish dorsal height and tip position. METHODS: Patients undergoing rhinoplasty had preoperative virtual 3D surgical simulations performed. Simulations were used to create a 3D printed nasal kits containing ceramic models of the preoperative nose and simulated nose, sagittal contour guide, and customized postoperative nasal splint. Nasal guides were sterilized for continual intraoperative assessment of profile contour (i.e., dorsal height and tip position). Postoperative 3D images (1-3 months post-op) were then compared to preoperative simulations. The difference between z coordinates and y coordinates determined the difference in projection and rotation, respectively. RESULTS: Fifteen patients met inclusion criteria for this study. With the use of 3D printed surgical guides, the final tip position was on average of 0.8±0.7mm from simulated projection and 0.3±0.2mm from simulated rotation. Similarly, projection for the cartilaginous and bony dorsum was within 1.0±0.8 and 0.8±0.7mm of the simulation, respectively. CONCLUSION: Virtual simulation is useful in defining aesthetic goals preoperatively, but the potential clinical value extends beyond this. 3D printed rhinoplasty guides extend the simulation's utility to decision-making intraoperatively. This technology offers a novel medium for anatomic reference, which may improve adherence to desired aesthetic goals. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine Ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266 .

Cognitive load in 3d and 2d minimally invasive colorectal surgery.

BACKGROUND: Three-dimensional (3d) laparoscopy has been introduced to enhance depth perception and facilitate surgical operations. The aim of this study was to compare cognitive load during 3d and 2d laparoscopic procedures. METHODS: Two subjective questionnaires (the Simulator Sickness Questionnaire and the NASA task load index) were used to prospectively collect data regarding cognitive load in surgeons performing 2d and 3d laparoscopic colorectal resections. Moreover, the perioperative results of 3d and 2d laparoscopic operations were analyzed. RESULTS: A total of 313 patients were included: 82 in the 2d group and 231 in the 3d group. The NASA TLX results did not reveal significantly major cognitive load differences in the 3d group compared with the 2d group; the SSQ results were better in the 3d group than in the 2d group in terms of general discomfort, whereas difficulty concentrating, difficulty focusing, and fatigue were more frequent in 3d operations than in 2d operations (p = 0.001-0.038). The results of age, sex, and ASA score were comparable between the two groups (p = 0.299-0.374). The median operative time showed no statistically significant difference between the 3d and 2d groups (median, IQR, 2d 150 min [120-180]-3d 160 min [130-190] p = 0.611). There was no statistically significant difference in the risk of severe complications between patients in the 3d group and in the 2d group (2d 7 [8.54%] vs 3d 21 [9.1%], p = 0.271). The median hospitalization time and the reoperation rate showed no difference between the 2d and 3d operations (p = 0.417-0.843). CONCLUSION: The NASA TLX did not reveal a significant difference in cognitive load between the 2d and 3d groups, whereas data reported by the SSQ showed a mild risk of cognitive load in the 3d group. Furthermore, 3d laparoscopic surgery revealed the same postoperative results as 2d standard laparoscopy.

An infrared 3D scanning device as a novel limb volume measurement tool in breast cancer patients.

BACKGROUND: Lymphedema is a common complication of breast cancer treatment that affects one in five breast cancer survivors, yet there is no reliable method to detect lymphedema in the subclinical range. The objective of this study was to determine the feasibility and reliability of using an infrared 3D scanning device (ISD) as a peri-operative limb volume measurement tool. METHODS: Fifteen patients were analyzed based on inclusion criteria. Peri-operative measurements were obtained using tape measure and an ISD. Volumes were calculated using a standard algorithm for tape measure and a custom algorithm for ISD measurements. Linear regression models were used to assess ISD and tape measurement volume and circumference correlation. One-way ANOVA was used to compare change in percent difference at set time points post-operatively (2-3 weeks, 4-6 weeks, and 7-12 weeks) for both ISD and tape measure. t tests for unequal variances with the Bonferroni correction were performed among these groups. RESULTS: There is a positive linear correlation (R2 = 0.8518) between absolute volume measurements by the ISD and tape measure. Analyses over 2-10 weeks post-operatively showed that the ISD was able to detect volume changes in both the unaffected and the affected arm. Furthermore, the affected arm tended to have a greater increase in volume in the majority of patients, indicating these patients could be at risk for lymphedema. CONCLUSIONS: Technology utilizing infrared 3D scanners can reliably measure limb volume pre- and post-treatment similarly to tape measure in a small sample of patients. Further research using 3D scanning technology with a longer follow up is warranted.

[Contribution of 3D technology for maxillofacial surgery]. / Apport de la technologie 3D en chirurgie maxillo-faciale.

In recent years, 3D design and printing technology has been successfully used in maxillofacial bone reconstruction procedures. We had the opportunity to observe its benefits in the manufacture of custom facial implants. The production is so precise that perfect anatomical congruence and biocompatibility are possible. Within the plastic and maxillofacial surgery department of the University Hospital of Liège, we had the opportunity to perform two operations requiring facial skeleton redefinition implants. The purpose of this article is to highlight the current possibilities of facial prostheses via new 3D techno¬logies, but also the advantages and possible complications of this type of surgery.

Depuis quelques années, la technologie dite «conception et impression 3D¼ s'utilise avec succès dans les interventions de reconstruction osseuse maxillo-faciale. Nous en avons apprécié les bénéfices dans la confection d'implants faciaux sur mesure. La finesse de leur réalisation permet d'obtenir une parfaite congruence anatomique avec la meilleure biocompatibilité. Au sein du service de Chirurgie plastique et maxillo-faciale du CHU de Liège, nous avons effectué deux interventions avec implants 3D redéfinissant le squelette facial. Le but de cet article est de mettre en évidence les possibilités actuelles des implants faciaux via les nouvelles technologies 3D, mais également les avantages et les complications éventuelles de ce type de chirurgie.

[3d-technologies in hepatobiliary surgery]. / 3D-tekhnologii v gepatobiliarnoi khirurgii.

The authors describe modern 3D technologies in hepatobiliary surgery. These approaches reduce the risk of intra- and postoperative complications. Virtual 3D reconstruction with clear visualization of parasitic cyst, adjacent vessels and bile ducts is valuable to create 3D-model of liver. This model may be applied for personalized laparoscopic approach and precise surgical intervention.

[Design Elements of Medical Endoscope and Concerns of Registration Technical Evaluation].

From the point of view of medical device registration technical evaluation, production process of endoscope, three-dimensional imaging(3D), high resolution imaging are discussed. We focus on the process of design and development, especially verification and validation. The general principle is that all risks and unexpected impacts should be minimized and acceptable to ensure that benefits are greater than risks in normal use.

Measurements of the Vertical Displacements of a Railway Bridge Using TLS Technology in the Context of the Upgrade of the Polish Railway Transport.

The railway system in Poland is undergoing technological transformation. The development of the Polish railway system concerns not only high-speed trains but also infrastructure. The steel bridge is the most popular type of railway bridge in Poland. Most of them were built in the 1950s and 1960s. According to the recommendations in place in Western Europe, such railway bridges should be reviewed in terms of their fitness for use with modern high-speed trains. The modern technological revolution affects not only the railway, but also developments in displacement and deformation measurement techniques. New technologies provide more objective measurement results and accelerate results processing. They also facilitate the non-contact measurement of bridge structure stability. The authors investigated the vertical displacement of an old steel railway bridge in three different, specific case studies of terrestrial laser scanning data application. Then, the results of 3D data were compared with traditional land surveying results. The scientific results led to a conclusion that a strictly determined methodology of the measurement and analysis of a terrestrial laser scanner results supported by traditional land surveying techniques facilitates the determination of the vertical displacement of bridges with acceptable accuracy.

When to Introduce Three-Dimensional Visualization Technology into Surgical Residency: A Randomized Controlled Trial.

Three-dimensional (3D) reconstructed images have been increasingly applied for medical education. Although many studies have described the benefits of such applications, the best time to introduce 3D technology into surgical training has not been determined. Therefore, we conducted a randomized study to determine a suitable period for the introduction of this technology. Seventy-one surgical residents were randomized into 2 groups (two-dimensional computed tomography (CT) group and 3D image group), and they completed a test on anatomy and imaging as well as a questionnaire. Post-graduate year 1 (PGY1) residents in the 3D group performed significantly better than those in the CT group, although the third-year residents did not present significant differences in either the score or the time spent answering the questions. Although residents in different years of training held different attitudes toward the difficulty of anatomy and imaging learning, they all showed a high level of acceptance of the 3D training. This study revealed that 3D images improved the junior residents' performance in imaging reasoning. Thus, systematically introducing 3D images early in a surgical resident training program may help produce a better anatomy-imaging-surgery system.

Three-dimensional versus two-dimensional laparoscopic right colectomy: a systematic review and meta-analysis.

BACKGROUND: Three-dimensional (3D) vision technology has recently been validated for the improvement of surgical skills in a simulated setting. Clinical studies on specific operations have been published in the field of general, urologic, and gynecologic laparoscopic surgery. We hypothesized that 3D vision laparoscopic right colectomy has better intra and short-term postoperative outcomes than two-dimensional (2D) vision. AIM: The outcomes of this review and meta-analysis were to compare the 3D vision and the 2D vision laparoscopic right colectomy. METHODS: A systematic search of the literature was performed on Pubmed, WOS, Google Scholar, and Scopus databases (Prospero reg. nr. 42016047704) for comparative studies between 2D and 3D laparoscopic right colectomy. Primary endpoints were safety issues and secondarily patients' related and surgeons' comfort outcomes. Meta-analyses, when possible, were conducted with a random-effects model. RESULTS: Two retrospective comparative studies (for a total of 56 patients in the 2D arm and 52 patients for the 3D arm) were selected out of 680 screened records. Methodological quality was fair. Three-dimensional laparoscopic right colectomy has similar safety and secondary outcomes when compared to 2D, with not statistically significant shorter operating times (mean difference 11.81 min). The results are comparable also for anastomosis leakage. The results for other outcomes were not aggregated for heterogeneity. CONCLUSIONS: 3D laparoscopic right colectomy shows equivalent patients' outcomes compared to 2D operation, but the scarce clinical data and the potential amelioration of surgeons' skills, especially on difficult intracorporeal tasks like suturing, suggest the publication of further trials.

Augmented reality technology for preoperative planning and intraoperative navigation during hepatobiliary surgery: A review of current methods.

BACKGROUND: Augmented reality (AR) technology is used to reconstruct three-dimensional (3D) images of hepatic and biliary structures from computed tomography and magnetic resonance imaging data, and to superimpose the virtual images onto a view of the surgical field. In liver surgery, these superimposed virtual images help the surgeon to visualize intrahepatic structures and therefore, to operate precisely and to improve clinical outcomes. DATA SOURCES: The keywords "augmented reality", "liver", "laparoscopic" and "hepatectomy" were used for searching publications in the PubMed database. The primary source of literatures was from peer-reviewed journals up to December 2016. Additional articles were identified by manual search of references found in the key articles. RESULTS: In general, AR technology mainly includes 3D reconstruction, display, registration as well as tracking techniques and has recently been adopted gradually for liver surgeries including laparoscopy and laparotomy with video-based AR assisted laparoscopic resection as the main technical application. By applying AR technology, blood vessels and tumor structures in the liver can be displayed during surgery, which permits precise navigation during complex surgical procedures. Liver transformation and registration errors during surgery were the main factors that limit the application of AR technology. CONCLUSIONS: With recent advances, AR technologies have the potential to improve hepatobiliary surgical procedures. However, additional clinical studies will be required to evaluate AR as a tool for reducing postoperative morbidity and mortality and for the improvement of long-term clinical outcomes. Future research is needed in the fusion of multiple imaging modalities, improving biomechanical liver modeling, and enhancing image data processing and tracking technologies to increase the accuracy of current AR methods.