Feasibility of a novel augmented reality overlay for cervical screw placement in phantom spine models

Study Design

Feasibility study.

Purpose

A phantom model was used to evaluate the accuracy of a novel augmented reality (AR) system for cervical screw placement.

Overview of Literature

The use of navigation systems is becoming increasingly common in spine procedures. However, numerous factors limit the feasibility of regular and widespread use of navigation tools during spine surgery. AR is a new technology that has already demonstrated utility as a navigation tool during spine surgery. However, advancements in AR technology are needed to increase its adoption by the medical community.

Methods

AR technology that uses a fiducial-less registration system was tested in a preclinical cervical spine phantom model study for accuracy during spinal screw placement. A three-dimensional reconstruction of the spine along with trajectory lines was superimposed onto the phantom model using an AR headset. Participants used the AR system to guide screw placement, and post-instrumentation scans were compared for accuracy assessment.

Results

Twelve cervical screws were placed under AR guidance. All screws were placed in an acceptable anatomic position. The average distance error for the insertion point was 2.73±0.55 mm, whereas that for the endpoint was 2.71±0.69 mm. The average trajectory angle error for all insertions was 2.69°±0.59°.

Conclusions

This feasibility study describes a novel registration approach that superimposes spinal anatomy and trajectories onto the surgeon's real-world view of the spine. These results demonstrate reasonable accuracy in the preclinical model. The results of this study demonstrate that this technology can assist with accurate screw placement. Further investigation using cadaveric and clinical models is warranted.

Accuracy of implant placement using a mixed reality-based dynamic navigation system versus static computer-assisted and freehand surgery: An in Vitro study

PURPOSE

This in vitro study aimed to compare the accuracy of dental implant placement in partially edentulous maxillary models using a mixed reality-based dynamic navigation (MR-DN) system to conventional static computer-assisted implant surgery (s-CAIS) and a freehand (FH) method.

METHODS

Forty-five partially edentulous models (with teeth missing in positions #15, #16 and #25) were assigned to three groups (15 per group). The same experienced operator performed the model surgeries using an MR-DN system (group 1), s-CAIS (group 2) and FH (group 3). In total, 135 dental implants were placed (45 per group). The primary outcomes were the linear coronal deviation (entry error; En), apical deviation (apex error; Ap), XY and Z deviations, and angular deviation (An) between the planned and actual (post-surgery) position of the implants in the models. These deviations were computed as the distances between the stereolithographic (STL) files for the planned implants and placed implants captured with an intraoral scanner.

RESULTS

Across the three implant sites, the MR-DN system was significantly more accurate than the FH method (in XY, Z, En, Ap and An) and s-CAIS (in Z, Ap and An), respectively. However, S-CAIS was more accurate than MR-DN in XY, and no difference was found between MR-DN and s-CAIS in En.

CONCLUSIONS

Within the limits of this study (in vitro design, only partially edentulous models), implant placement accuracy with MR-DN was superior to that of FH and similar to that of s-CAIS.

STATEMENT OF CLINICAL RELEVANCE

In vitro, MR-DN showed greater accuracy in implant positioning than FH, and similar accuracy to s-CAIS: it could, therefore, represent a new option for the surgeon. However, clinical studies are needed to determine the feasibility of MR-DN.

Taxonomic discordance of immersive realities in dentistry: A systematic scoping review.: Taxonomic discordance of immersive realities

OBJECTIVES

This review aimed to map taxonomy frameworks, descriptions, and applications of immersive technologies in the dental literature.

DATA

The Preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews (PRISMA-ScR) guidelines was followed, and the protocol was registered at open science framework platform (https://doi.org/10.17605/OSF.IO/H6N8M).

SOURCES

Systematic search was conducted in MEDLINE (via PubMed), Scopus, and Cochrane Library databases, and complemented by manual search.

STUDY SELECTION

A total of 84 articles were included, with 81% between 2019 and 2023. Most studies were experimental (62%), including education (25%), protocol feasibility (20%), in vitro (11%), and cadaver (6%). Other study types included clinical report/technique article (24%), clinical study (9%), technical note/tip to reader (4%), and randomized controlled trial (1%). Three-quarters of the included studies were published in oral and maxillofacial surgery (38%), dental education (26%), and implant (12%) disciplines. Methods of display included head mounted display device (HMD) (55%), see through screen (32%), 2D screen display (11%), and projector display (2%). Descriptions of immersive realities were fragmented and inconsistent with lack of clear taxonomy framework for the umbrella and the subset terms including virtual reality (VR), augmented reality (AR), mixed reality (MR), augmented virtuality (AV), extended reality, and X reality.

CONCLUSIONS

Immersive reality applications in dentistry are gaining popularity with a notable surge in the number of publications in the last 5 years. Ambiguities are apparent in the descriptions of immersive realities. A taxonomy framework based on method of display (full or partial) and reality class (VR, AR, or MR) is proposed.

CLINICAL SIGNIFICANCE

Understanding different reality classes can be perplexing due to their blurred boundaries and conceptual overlapping. Immersive technologies offer novel educational and clinical applications. This domain is fast developing. With the current fragmented and inconsistent terminologies, a comprehensive taxonomy framework is necessary.

Neural digital twins: reconstructing complex medical environments for spatial planning in virtual reality

PURPOSE

Specialized robotic and surgical tools are increasing the complexity of operating rooms (ORs), requiring elaborate preparation especially when techniques or devices are to be used for the first time. Spatial planning can improve efficiency and identify procedural obstacles ahead of time, but real ORs offer little availability to optimize space utilization. Methods for creating reconstructions of physical setups, i.e., digital twins, are needed to enable immersive spatial planning of such complex environments in virtual reality.

METHODS

We present a neural rendering-based method to create immersive digital twins of complex medical environments and devices from casual video capture that enables spatial planning of surgical scenarios. To evaluate our approach we recreate two operating rooms and ten objects through neural reconstruction, then conduct a user study with 21 graduate students carrying out planning tasks in the resulting virtual environment. We analyze task load, presence, perceived utility, plus exploration and interaction behavior compared to low visual complexity versions of the same environments.

RESULTS

Results show significantly increased perceived utility and presence using the neural reconstruction-based environments, combined with higher perceived workload and exploratory behavior. There's no significant difference in interactivity.

CONCLUSION

We explore the feasibility of using modern reconstruction techniques to create digital twins of complex medical environments and objects. Without requiring expert knowledge or specialized hardware, users can create, explore and interact with objects in virtual environments. Results indicate benefits like high perceived utility while being technically approachable, which may indicate promise of this approach for spatial planning and beyond.

Extended reality in cranial and spinal neurosurgery - a bibliometric analysis

PURPOSE

This bibliometric analysis of the top 100 cited articles on extended reality (XR) in neurosurgery aimed to reveal trends in this research field. Gender differences in authorship and global distribution of the most-cited articles were also addressed.

METHODS

A Web of Science electronic database search was conducted. The top 100 most-cited articles related to the scope of this review were retrieved and analyzed for trends in publications, journal characteristics, authorship, global distribution, study design, and focus areas. After a brief description of the top 100 publications, a comparative analysis between spinal and cranial publications was performed.

RESULTS

From 2005, there was a significant increase in spinal neurosurgery publications with a focus on pedicle screw placement. Most articles were original research studies, with an emphasis on augmented reality (AR). In cranial neurosurgery, there was no notable increase in publications. There was an increase in studies assessing both AR and virtual reality (VR) research, with a notable emphasis on VR compared to AR. Education, surgical skills assessment, and surgical planning were more common themes in cranial studies compared to spinal studies. Female authorship was notably low in both groups, with no significant increase over time. The USA and Canada contributed most of the publications in the research field.

CONCLUSIONS

Research regarding the use of XR in neurosurgery increased significantly from 2005. Cranial research focused on VR and resident education while spinal research focused on AR and neuronavigation. Female authorship was underrepresented. North America provides most of the high-impact research in this area.

Visual extended reality tools in image-guided surgery in urology: a systematic review

PURPOSE

The aim of this systematic review is to assess the clinical implications of employing various Extended Reality (XR) tools for image guidance in urological surgery.

METHODS

In June 2023, a systematic electronic literature search was conducted using the Medline database (via PubMed), Embase (via Ovid), Scopus, and Web of Science. The search strategy was designed based on the PICO (Patients, Intervention, Comparison, Outcome) criteria. Study protocol was registered on PROSPERO (registry number CRD42023449025). We incorporated retrospective and prospective comparative studies, along with single-arm studies, which provided information on the use of XR, Mixed Reality (MR), Augmented Reality (AR), and Virtual Reality (VR) in urological surgical procedures. Studies that were not written in English, non-original investigations, and those involving experimental research on animals or cadavers were excluded from our analysis. The quality assessment of comparative and cohort studies was conducted utilizing the Newcastle-Ottawa scale, whilst for randomized controlled trials (RCTs), the Jadad scale was adopted. The level of evidence for each study was determined based on the guidelines provided by the Oxford Centre for Evidence-Based Medicine.

RESULTS

The initial electronic search yielded 1,803 papers after removing duplicates. Among these, 58 publications underwent a comprehensive review, leading to the inclusion of 40 studies that met the specified criteria for analysis. 11, 20 and 9 studies tested XR on prostate cancer, kidney cancer and miscellaneous, including bladder cancer and lithiasis surgeries, respectively. Focusing on the different technologies 20, 15 and 5 explored the potential of VR, AR and MR. The majority of the included studies (i.e., 22) were prospective non-randomized, whilst 7 and 11 were RCT and retrospective studies respectively. The included studies that revealed how these new tools can be useful both in preoperative and intraoperative setting for a tailored surgical approach.

CONCLUSIONS

AR, VR and MR techniques have emerged as highly effective new tools for image-guided surgery, especially for urologic oncology. Nevertheless, the complete clinical advantages of these innovations are still in the process of evaluation.

Virtual Reality and Mixed Reality-Assisted Endoscopic DCR in Extremely Complex Lacrimal Obstructions

OBJECTIVE

To report the techniques and outcomes of virtual reality (VR) and mixed reality (MR)-assisted powered endoscopic dacryocystorhinostomy (DCR) in extremely complex lacrimal drainage obstructions.

METHODS

A prospective, non-randomized clinical study was performed in complex syndromic congenital nasolacrimal duct obstruction (CNLDO) and post-traumatic secondary acquired lacrimal duct obstruction (SALDO) in the setting of Le Fort fractures. All patients underwent preoperative planning in VR and intraoperative planning with a step ahead with MR assistance during the surgery. Surgery was supported by mixed reality intraoperative guidance with the use of the prearranged 3D models and real-time-rendered digital models. Parameters assessed include demographics, clinical presentation, complexities of the nasolacrimal duct obstruction, preoperative and intraoperative utility of VR and MR models, surgical techniques, complications, and outcomes.

RESULTS

The technique is described as a proof of concept in challenging situations with Apert syndrome and traumatic SALDOs with gross malposition of the sac, and gross nasal and lacrimal anatomical deformities. The VR models helped the surgeon to assess the details of the altered anatomy preoperatively to plan an appropriate approach. Intraoperatively, MR models were present in the surgeon's view without disturbing the endoscopic procedure. Intermittently, the surgeon could pull any of the models virtually present in the operating room, slice them, rotate them, and intricately study the alterations in a stepwise manner, as the surgery proceeds.

CONCLUSION

Virtual reality and mixed reality-assisted powered endoscopic DCR can be an alternate approach reserved for extremely challenging cases of complex syndromic CNLDOs and post-traumatic SALDOs.

LEVEL OF EVIDENCE

Level 4 Laryngoscope, 2024.

The bibliometric analysis of extended reality in surgical training: Global and Chinese perspective

Objectives

The prospect of extended reality (XR) being integrated with surgical training curriculum has attracted scholars. However, there is a lack of bibliometric analysis to help them better understand this field. Our aim is to analyze relevant literature focusing on development trajectory and research directions since the 21st century to provide valuable insights.

Methods

Papers were retrieved from the Web of Science Core Collection. Microsoft Excel, VOSviewer, and CiteSpace were used for bibliometric analysis.

Results

Of the 3337 papers published worldwide, China contributed 204, ranking fifth. The world's enthusiasm for this field has been growing since 2000, whereas China has been gradually entering since 2001. Although China had a late start, its growth has accelerated since around 2016 due to the reform of the medical postgraduate education system and the rapid development of Chinese information technology, despite no research explosive period has been yet noted. International institutions, notably the University of Toronto, worked closely with others, while Chinese institutions lacked of international and domestic cooperation. Sixteen stable cooperation clusters of international scholars were formed, while the collaboration between Chinese scholars was not yet stable. XR has been primarily applied in orthopedic surgery, cataract surgery, laparoscopic training and intraoperative use in neurosurgery worldwide.

Conclusions

There is strong enthusiasm and cooperation in the international research on the XR-based surgical training. Chinese scholars are making steady progress and have great potential in this area. There has not been noted an explosive research phase yet in the Chinese pace. The research on several surgical specialties has been summarized at the very first time. AR will gradually to be more involved and take important role of the research.

Assessing the impact of mixed reality-assisted informed consent: A study protocol

Background

Informed consent is a crucial aspect of modern medicine, but it can be challenging due to the complexity of the information involved. Mixed reality (MR) has emerged as a promising technology to improve communication. However, there is a lack of comprehensive research on the impact of MR on medical informed consent. The proposed research protocol provides a solid foundation for conducting future investigations and developing MR-based protocols that can enhance patients' understanding and engagement in the decision-making process.

Methods

This study will employ a randomized controlled trial design. Two arms will be defined: MR-assisted informed consent (MRaIC) as the experimental arm and conventional informed consent (CIC) as the control arm consent, with 52 patients in each group. The protocol includes the use of questionnaires to analyze the anxiety levels and the awareness of the procedure that the patient is going to perform to study the impact of MRaIC versus CIC before medical procedures.

Results

The study will evaluate the impact of MR on patients' information comprehension, engagement during the process of obtaining informed consent, emotional reactions, and consent decisions. Ethical concerns will be addressed.

Conclusion

This study protocol provides a comprehensive approach to investigate the impact of MR on medical informed consent. The findings may contribute to a better understanding of the effects of MR on information comprehension, engagement during the process of obtaining informed consent, psychological experience, consent decisions, and ethical considerations. The integration of MR technology has the potential to enhance surgical communication practices and improve the informed consent process.

Relationship between demographic and social variables and performance in virtual reality among healthcare personnel: an observational study

BACKGROUND

Virtual reality is emerging as an important component of medical education. Although the benefits of virtual reality are apparent, the optimal strategy to orient to or differentiate learners in the virtual space have not been delineated. The purpose of this study was to investigate the relationships between demographic variables, social variables, and self-perceived comfort with technology to performance on a standardized non-medical virtual reality experience.

METHODS

This observational study was performed at the International Meeting on Simulation in Healthcare in 2022. This conference includes medical and non-medical attendees. Participants provided demographic information and participated in a scored non-medical VR experience due to the heterogeneity of the sample. Participants then completed a System Usability Index and NASA Task Load Index form. Participants were dividedintolow scoring, medium scoring, and high scoring groups according to their final game score for further analysis.

RESULTS

95 participants were included in final analysis. 55 (57.9%) of participants had prior virtual reality experience. Higher scores were associated with younger age (11.09, p < 0.001), identifying as male (11.09, p < 0.001), and a higher frequency of playing video games in the past (18.96, p < 0.001). The high score group was more likely to report comfort with virtual reality (6.29, p = 0.003) as well as comfort with new technology (4.61, p = 0.012). NASA Task Load Index scores trended down and System Usability Index scores trended up with increasing score. Being a nurse was a positive predictor of a higher score when compared to physicians in the multivariate analysis.

CONCLUSION

Performance during an immersive virtual reality experience was most closely related to age, gender, and frequency of playing video games. Self-perceived comfort with virtual reality was more predictive of score than prior virtual reality experience.

How I do it? Surgical clipping of a large right internal carotid artery-superior hypophyseal artery aneurysm

BACKGROUND

Microsurgery alone often proves to be challenging in treating paraclinoid internal carotid artery (ICA) aneurysms, which are known for their complex anatomy.

METHOD

A 53-year-old female with a large right ICA-superior hypophyseal artery (SHA) aneurysm underwent clipping repair. Mixed reality technology was utilized in the preoperative planning and anatomical study. During the surgery, the anterior clinoid process was removed intradurally to improve access to the aneurysm neck. The aneurysm was then secured with a long curved clip. The patient's recovery was successful without any complications.

CONCLUSION

This report aims to shed light on the intricacies involved in clipping ICA-SHA aneurysms.

Exploring mobile mixed reality for critical thinking in nursing and healthcare education: A systematic review

BACKGROUND

The shortage of nursing and healthcare clinical placements has prompted the investigation of ways to supplement authentic learning. Mobile mixed reality has become increasingly available, however, the affordances and design principles for the facilitation of critical thinking are yet to be explored.

OBJECTIVE

To examine how mobile mixed reality facilitates critical thinking in nursing and healthcare higher education.

DESIGN

Systematic review.

REVIEW METHODS

A search in seven databases (MEDLINE, PsychINFO, AMED, ERIC, Scopus, Cochrane, and Web of Science) was conducted with 3488 titles and abstracts screened. The quality of the included studies was evaluated using the Mixed Methods Assessment Tool (MMAT).

RESULTS

A total of 12 studies with 1108 participants were included. The breadth of healthcare disciplines was limited to five disciplines that utilised bespoke scenarios on head-mounted displays. Most scenarios were emergency or critical response, with limited time for pre-brief, debrief, or overall user time. Only two studies directly measured critical thinking, with others including indirect reference to diagnoses, interpretation, analysis, or evaluation of healthcare scenarios. Affordances and design principles for the future development of mobile mixed reality for critical thinking in nursing and healthcare higher education are identified.

CONCLUSIONS

While some pedagogical affordances of mobile mixed reality can be identified in a narrow number of healthcare disciplines, there remain to be limited valid measures of critical thinking used to quantify effectiveness. Future studies would benefit from considering scenarios beyond emergency and critical responses, including longitudinal studies that reflect the development of critical thinking over time, and exploration of co-designed scenarios with and by nursing and healthcare students.

Augmented Reality Registration System for Visualization of Skull Landmarks

BACKGROUND

Augmented reality (AR) is an emerging technology in neurosurgery with the potential to become a strategic tool in the delivery of care and education for trainees. Advances in technology have demonstrated promising use for improving visualization and spatial awareness of critical neuroanatomic structures. In this report, we employ a novel AR registration system for the visualization and targeting of skull landmarks.

METHODS

A markerless AR system was used to register 3-dimensional reconstructions of suture lines onto the head via a head-mounted display. Participants were required to identify craniometric points with and without AR assistance. Targeting error was measured as the Euclidian distance between the user-defined location and the true craniometric point on the subjects' heads.

RESULTS

All participants successfully registered 3-dimensional reconstructions onto the subjects' heads. Targeting accuracy was significantly improved with AR (3.59 ± 1.29 mm). Across all target points, AR increased accuracy by an average of 19.96 ± 3.80 mm. Posttest surveys revealed that participants felt the technology increased their confidence in identifying landmarks (4.6/5) and that the technology will be useful for clinical care (4.2/5).

CONCLUSIONS

While several areas of improvement and innovation can further enhance the use of AR in neurosurgery, this report demonstrates the feasibility of a markerless headset-based AR system for visualizing craniometric points on the skull. As the technology continues to advance, AR is expected to play an increasingly significant role in neurosurgery, transforming how surgeries are performed and improving patient care.

The use of mixed reality in the preoperative planning of colorectal surgery: Preliminary experience with a narrative review

New advanced technologies have recently been developed and preliminarily applied to surgery, including virtual reality (VR), augmented reality (AR) and mixed reality (MR). We retrospectively review all colorectal cases in which we used holographic 3D reconstruction from February 2020 to December 2022. This innovative approach was used to identify vascular anomalies, pinpoint tumor locations, evaluate infiltration into neighboring organs and devise surgical plans for both training and educating trainee assistants. We have also provided a state-of-the-art analysis, briefly highlighting what has been stated by the scientific literature to date. VR facilitates training and anatomical assessments, while AR enhances training and laparoscopic performance evaluations. MR, powered by HoloLens, enriches anatomic recognition, navigation, and visualization. Successful implementation was observed in 10 colorectal cancer cases, showcasing the effectiveness of MR in improving preoperative planning and its intraoperative application. This technology holds significant promise for advancing colorectal surgery by elevating safety and reliability standards.

Advanced Visualization Engineering for Vision Disorders: A Clinically Focused Guide to Current Technology and Future Applications

Head-mounted visualization technology, often in the form of virtual, augmented, and mixed reality (VAMR), has revolutionized how visual disorders may be approached clinically. In this manuscript, we review the available literature on VAMR for visual disorders and provide a clinically oriented guide to how VAMR technology has been deployed for visual impairments. The chief areas of clinical investigation with VAMR are divided include (1) vision assessment, (2) vision simulation, and (3) vision rehabilitation. We discuss in-depth the current literature of these areas in VAMR and upcoming/future applications to combat the detrimental impact of visual impairment worldwide.

An interactive augmented reality software for facial reconstructive surgeries

BACKGROUND AND OBJECTIVE

Surgical trainees need a lot of training and practice before being able to operate independently. The current approach of surgical education mainly involves didactic teaching and psychomotor training through physical models or real tissue. Due to the unavailability of physical resources and lack of objective ways of evaluation, there is a demand for developing alternative training methods for surgeons. In this paper, we present an application that provides additional training opportunities to surgical trainees in the field of facial reconstructive surgeries.

METHODS

We built a mobile augmented reality application that helps the user to visualize important concepts and experiment with different surgical plans for facial reconstructive surgeries. The application can overlay relaxed skin tension lines on a live video input or a patient's photo, which serve as bases for aligning a skin flap. A surgical trainee can interactively compare different skin flap design choices with estimated final scars on a photo of a patient. Data collection capability is also added to the application, and we performed a Monte Carlo experiment with simulated users (five classes of 100 users each) as an example of objectively measuring user performance.

RESULTS

The application can overlay relaxed skin tension lines on a patient's face in real time on a modern mobile device. Accurate overlays were achieved in over 91% as well as 84% and 88% out of 263 generated face images, depending on the method. Visual comparisons of the three overlay methods are presented on sample faces from different population groups. From the Monte Carlo experiment, we see that user actions in each class follow a normal distribution with a distinct set of parameters.

CONCLUSIONS

This application can serve as a basis for teaching surgical trainees the fundamentals of different facial reconstructive procedures, especially concepts related to relaxed skin tension lines and skin flaps. It can objectively evaluate the performance of surgical trainees in a course. This setup focuses on illustrating the relationship between the orientation of skin flaps and relaxed skin tension lines, which is a prerequisite of minimizing scarring in patients in addition to good surgical techniques.

Augmented reality in spine surgery - past, present, and future

BACKGROUND CONTEXT

Augmented reality (AR) is increasingly recognized as a valuable tool in spine surgery. Here we provides an overview of the key developments and technological milestones that have laid the foundation for AR applications in this field. We also assess the quality of existing studies on AR systems in spine surgery and explore potential future applications.

PURPOSE

The purpose of this narrative review is to examine the role of AR in spine surgery. It aims to highlight the evolution of AR technology in this context, evaluate the existing body of research, and outline potential future directions for integrating AR into spine surgery.

STUDY DESIGN

Narrative review.

METHODS

We conducted a thorough literature search to identify studies and developments related to AR in spine surgery. Relevant articles, reports, and technological advancements were analyzed to establish the historical context and current state of AR in this field.

RESULTS

The review identifies significant milestones in the development of AR technology for spine surgery. It discusses the growing body of research and highlights the strengths and weaknesses of existing investigations. Additionally, it presents insights into the potential for AR to enhance spine surgical education and speculates on future applications.

CONCLUSIONS

Augmented reality has emerged as a promising adjunct in spine surgery, with notable advancements and research efforts. The integration of AR into the spine surgery operating room holds promise, as does its potential to revolutionize surgical education. Future applications of AR in spine surgery may include real-time navigation, enhanced visualization, and improved patient outcomes. Continued development and evaluation of AR technology are essential for its successful implementation in this specialized surgical field.

Feasibility and accuracy of real-time 3D-holographic graft length measurements

Aims

Mixed reality (MR) holograms can display high-definition images while preserving the user's situational awareness. New MR software can measure 3D objects with gestures and voice commands; however, these measurements have not been validated. We aimed to assess the feasibility and accuracy of using 3D holograms for measuring the length of coronary artery bypass grafts.

Methods and results

An independent core lab analyzed follow-up computer tomography coronary angiograms performed 30 days after coronary artery bypass grafting in 30 consecutive cases enrolled in the FASTTRACK CABG trial. Two analysts, blinded to clinical information, performed holographic reconstruction and measurements using the CarnaLife Holo software (Medapp, Krakow, Poland). Inter-observer agreement was assessed in the first 20 cases. Another analyst performed the validation measurements using the CardIQ W8 CT system (GE Healthcare, Milwaukee, Wisconsin). Seventy grafts (30 left internal mammary artery grafts, 31 saphenous vein grafts, and 9 right internal mammary artery grafts) were measured. Holographic measurements were feasible in 97.1% of grafts and took 3 minutes 36 s ± 50.74 s per case. There was an excellent inter-observer agreement [interclass correlation coefficient (ICC) 0.99 (0.97-0.99)]. There was no significant difference between the total graft length on hologram and CT [187.5 mm (157.7-211.4) vs. 183.1 mm (156.8-206.1), P = 0.50], respectively. Hologram and CT measurements are highly correlated (r = 0.97, P < 0.001) with an excellent agreement [ICC 0.98 (0.97-0.99)].

Conclusion

Real-time holographic measurements are feasible, quick, and accurate even for tortuous bypass grafts. This new methodology can empower clinicians to visualize and measure 3D images by themselves and may provide insights for procedural strategy.

Reliability of repeated exposure to the human elevated plus-maze in virtual reality: Behavioral, emotional, and autonomic responses

Approach-avoidance conflicts are a hallmark of anxiety-related behaviors. A gold standard for assessing anxiety-related behaviors in rodents is the elevated plus-maze (EPM), which was recently translated to humans using immersive virtual reality. Repeated behavioral testing is particularly interesting for clinical and pharmacological research in humans but could be limited by habituation effects. Here, we tested whether comparable strategies that are used in rodents (different environments and inter-trial interval of 28 days) are sufficient to avoid habituation or sensitization effects on the EPM, making it possible to perform repeated measurement of anxiety-related behavior in humans. Moreover, we developed two novel virtual environments for repeated testing to explore whether a scenario resembling the real world is superior to a video game-like EPM in terms of lifelike physiological, emotional, and behavioral responses. On a behavioral level, no significant differences but a high correlation between first and repeated exposure to the human EPM independent of EPM version were found. On a psychophysiological level, salivary alpha-amylase, skin-conductance, and respiratory frequency increased at first and second exposure independent of EPM version. However, at repeated exposure, skin-conductance and heart rate showed indicators for anticipatory anxiety and a small sensitization effect, while no effect of real-world resemblance on these physiological measures was found. This was also reflected in slightly higher subjective anxiety levels at second exposure, although subjective anxiety still correlated strongly between first and second exposure. In conclusion, the human EPM can be used for longitudinal assessments of human anxiety-related behavior when strategies to avoid habituation and sensitization are considered.

Case report: Use of markerless augmented reality system for ventriculoperitoneal shunt placement

Background

Ventriculoperitoneal (VP) shunt placement is one of the most commonly performed neurosurgical procedures, yet failure rates remain very high. Surface landmarks are typically used to guide VP shunt placement, but they are not reliable in identifying the target anatomy. Augmented reality (AR) is a promising new technology that has the potential to improve the accuracy and effectiveness of neurosurgical procedures. We describe the use of AR for the surgical planning of a VP shunt.

Case Description

A 62-year-old male with a history of subarachnoid hemorrhage presented with delayed hydrocephalus. A computed tomography scan was obtained that confirmed dilated ventricles, requiring a right VP shunt. The patient was brought to the operating room, where the AR system was used for visualization and planning.

Conclusion

In this study, we describe the use of AR for VP shunt placement. The AR system consists of a Microsoft HoloLens 2 head-mounted display and a novel markerless registration system, which was used to register patient-specific 3D models onto the patient's head for visualizing target anatomy and planning an operative approach. The AR system was used to plan the VP shunt placement in the operating room. This system is easy to use and provides a visualization of the patient's anatomy, which can be used to plan an optimal trajectory. We believe that this has the potential to improve the accuracy and outcomes of VP shunt placements, and further studies are needed to characterize the system's accuracy and benefits.

Effect of Intraoperative Mixed-Reality use on Nonsurgical Team Members in the Neurosurgical Operating Room: An Explorative Study

OBJECTIVES

Mixed-reality (MxR) implementation in the neurosurgical operating room (OR) is emerging, but the impact of this technology on the nonsurgical OR staff has not been investigated yet. The purpose of this study is to evaluate the nonsurgical OR team's perception of the impact of intraoperative MxR use.

METHODS

The evaluation occurred in a neurosurgical institution implementing MxR perioperatively on a daily basis for 15 months. The questionnaire measuring the impact of MxR consisted of 5 binary questions and 4 subquestions measured on a 7-point Likert scale.

RESULTS

Fifteen nonsurgical staff members of a neurosurgical OR team were interviewed. Most (85%) of the cohort stated that MxR changed their perception of the surgery, improving understanding of the spatial orientation (median 6, interquartile range 5-7) and of the pathology dimensions (6, 5.5-7). One participant (7%) was of the opinion that MxR disrupted the OR workflow. The majority (60%) stated that use of the holograms improved efficiency in the OR. The participants were neutral about the potential role of MxR to improve communication among different OR team members (4, 2-5) and overall teamwork (4, 2-5).

CONCLUSIONS

The use of 3-Dimensional interactive holograms of neurosurgical cases in the nonsterile intraoperative phase was not perceived as distractive, and neither was OR flow disruption by members of the nonsurgical OR staff. MxR was considered an adjunct to improve OR efficiency. A thorough understanding of the impact of MxR's implementation on the nonsurgical staff could lead to targeted improvement of the MxR use and, potentially, to increasing the quality of the teamwork.

A new mixed reality tool for training in minimally invasive robotic-assisted surgery

Robotic-assisted surgery (RAS) is developing an increasing role in surgical practice. Therefore, it is of the utmost importance to introduce this paradigm into surgical training programs. However, the steep learning curve of RAS remains a problem that hinders the development and widespread use of this surgical paradigm. For this reason, it is important to be able to train surgeons in the use of RAS procedures. RAS involves distinctive features that makes its learning different to other minimally invasive surgical procedures. One of these features is that the surgeons operate using a stereoscopic console. Therefore, it is necessary to perform RAS training stereoscopically. This article presents a mixed-reality (MR) tool for the stereoscopic visualization, annotation and collaborative display of RAS surgical procedures. The tool is an MR application because it can display real stereoscopic content and augment it with virtual elements (annotations) properly registered in 3D and tracked over time. This new tool allows the registration of surgical procedures, teachers (experts) and students (trainees), so that the teacher can share a set of videos with their students, annotate them with virtual information and use a shared virtual pointer with the students. The students can visualize the videos within a web environment using their personal mobile phones or a desktop stereo system. The use of the tool has been assessed by a group of 15 surgeons during a robotic-surgery master's course. The results show that surgeons consider that this tool can be very useful in RAS training.

Application of Mixed Reality to Ultrasound-guided Femoral Arterial Cannulation During Real-time Practice in Cardiac Interventions

Mixed reality opens interesting possibilities as it allows physicians to interact with both, the real physical and the virtual computer-generated environment and objects, in a powerful way. A mixed reality system, based in the HoloLens 2 glasses, has been developed to assist cardiologists in a quite complex interventional procedure: the ultrasound-guided femoral arterial cannulations, during real-time practice in interventional cardiology. The system is divided into two modules, the transmitter module, responsible for sending medical images to HoloLens 2 glasses, and the receiver module, hosted in the HoloLens 2, which renders those medical images, allowing the practitioner to watch and manage them in a 3D environment. The system has been successfully used, between November 2021 and August 2022, in up to 9 interventions by 2 different practitioners, in a large public hospital in central Spain. The practitioners using the system confirmed it as easy to use, reliable, real-time, reachable, and cost-effective, allowing a reduction of operating times, a better control of typical errors associated to the interventional procedure, and opening the possibility to use the medical imagery produced in ubiquitous e-learning. These strengths and opportunities were only nuanced by the risk of potential medical complications emerging from system malfunction or operator errors when using the system (e.g., unexpected momentary lag). In summary, the proposed system can be taken as a realistic proof of concept of how mixed reality technologies can support practitioners when performing interventional and surgical procedures during real-time daily practice.

Assessment of the viability of integrating virtual reality programs in practical tests for the Korean Radiological Technologists Licensing Examination: a survey study

PURPOSE

The objective of this study was to assess the feasibility of incorporating virtual reality/augmented reality (VR/AR) programs into practical tests administered as part of the Korean Radiological Technologists Licensing Examination (KRTLE). This evaluation is grounded in a comprehensive survey that targeted enrolled students in departments of radiology across the nation.

METHODS

In total, 682 students from radiology departments across the nation were participants in the survey. An online survey platform was used, and the questionnaire was structured into 5 distinct sections and 27 questions. A frequency analysis for each section of the survey was conducted using IBM SPSS ver. 27.0.

RESULTS

Direct or indirect exposure to VR/AR content was reported by 67.7% of all respondents. Furthermore, 55.4% of the respondents expressed that VR/AR could be integrated into their classes, which signified a widespread acknowledgment of VR among the students. With regards to the integration of a VR/AR or mixed reality program into the practical tests for purposes of the KRTLE, a substantial amount of the respondents (57.3%) exhibited a positive inclination and recommended its introduction.

CONCLUSION

The application of VR/AR programs within practical tests of the KRTLE will be used as an alternative for evaluating clinical examination procedures and validating job skills.

How I do it? Preoperative Microsoft HoloLens 2 planning-assisted surgical clipping of a fetal posterior cerebral artery aneurysm

BACKGROUND

The treatment of intracranial aneurysms has predominantly shifted towards endovascular strategies, but complex cases still necessitate microsurgery. Preoperative stimulation can be beneficial for inexperienced young neurosurgeons in preparing for safe microsurgery.

METHOD

A 72-year-old female with a left irregular fetal posterior cerebral artery (PCA) aneurysm underwent clipping repair. Microsoft HoloLens 2, utilizing mixed reality technology, was employed for preoperative stimulation and anatomical study. During the operation, we successfully identified the planned relationship between the aneurysm and the fetal PCA. The patient was cured without any complications.

CONCLUSION

We hope that this report will highlight the significance of Microsoft HoloLens 2 in microsurgical planning and education.

Challenges and promises of mixed-reality interventions in acquired brain injury rehabilitation: A scoping review

BACKGROUND

Acquired brain injury (ABI) can lead to significant impairments and difficulties in everyday life, necessitating the need for rehabilitation. Mixed-reality (MR) technologies have revolutionized the delivery of neurorehabilitation therapies. However, inconsistencies in research methodology, diverse study populations and designs, and exaggerated claims in the research, media, and private consumer sectors have impacted the knowledge base of the field, including within the context of ABI rehabilitation.

OBJECTIVE

This scoping review aims to explore MR-systems in ABI rehabilitation, while assessing the evidence base and technology readiness levels of these systems.

METHODS

Seven databases were searched for studies, which were screened and analyzed by two independent raters. The types of MR systems, levels of evidence, and technology readiness levels were extracted and analyzed using descriptive analyses.

RESULTS

Twenty-six studies were included in the review, all of which focused on ABI etiologies stemming from strokes. Across studies, upper-limb motor rehabilitation was the most common rehabilitation target of MR interventions, followed by gait, cognition, and lower-extremity functioning. At present, overall results indicate low evidence for MR-applications in ABI rehabilitation, with a median technology readiness level of 6, corresponding to system prototypes being tested in relevant environments.

CONCLUSION

Although challenges regarding system usability and design were reported, results appear promising with ongoing research. With variability across studies, technologies, and populations, determining the effectiveness of MR interventions in ABI remains a challenge, necessitating the need for ongoing innovation, research, and development of these systems.

Educational value of mixed reality combined with a three-dimensional printed model of aortic disease for vascular surgery in the standardized residency training of surgical residents in China: a case control study

BACKGROUND

The simulated three-dimensional (3D) printed anatomical model of the aorta, which has become the norm in medical education, has poor authenticity, tactility, feasibility, and interactivity. Therefore, this study explored the educational value and effect of mixed reality (MR) combined with a 3D printed model of aortic disease in training surgical residents.

METHOD

Fifty-one resident physicians who rotated in vascular surgery were selected and divided into traditional (27) and experimental (24) teaching groups using the random number table method. After undergoing the experimental and traditional training routines on aortic disease, both the groups took a theoretical test on aortic disease and an assessment of the simulation based on the Michigan Standard Simulation Experience Scale (MiSSES) template. Their scores and assessment results were compared. The study was conducted at the Department of Vascular Surgery of Peking University People's Hospital, Beijing, China.

RESULTS

In the theoretical test on aortic disease, the experimental teaching group obtained higher mean total scores (79.0 ± 9.1 vs. 72.6 ± 7.5, P = 0.013) and higher scores in anatomy/ pathophysiology (30.8 ± 5.4 vs. 24.8 ± 5.8; P < 0.001) than the traditional teaching group. The differences in their scores in the differential diagnosis (25.8 ± 3.0 vs. 23.3 ± 4.9; P = 0.078) and treatment (22.5 ± 11.8 vs. 24.5 ± 8.2; P = 0.603) sessions were insignificant. The MR-assisted teaching stratified the vascular residents through the MiSSES survey. Overall, 95.8% residents (23/24) strongly or somewhat agreed that the MR was adequately realistic and the curriculum helped improve the ability to understanding aortic diseases. Further, 91.7% residents (22/24) strongly or somewhat agreed that the MR-assisted teaching was a good training tool for knowledge on aortic diseases. All residents responded with "Good" or "Outstanding" on the overall rating of the MR experience.

CONCLUSIONS

MR combined with the 3D printed model helped residents understand and master aortic disease, particularly regarding anatomy and pathophysiology. Additionally, the realistic 3D printing and MR models improved the self-efficacy of residents in studying aortic diseases, thus greatly stimulating their enthusiasm and initiative to study.

A novel mixed reality-guided dental implant placement navigation system based on virtual-actual registration

BACKGROUNDS

The key to successful dental implant surgery is to place the implants accurately along the pre-operative planned paths. The application of surgical navigation systems can significantly improve the safety and accuracy of implantation. However, the frequent shift of the views of the surgeon between the surgical site and the computer screen causes troubles, which is expected to be solved by the introduction of mixed-reality technology through the wearing of HoloLens devices by enabling the alignment of the virtual three-dimensional (3D) image with the actual surgical site in the same field of view.

METHODS

This study utilized mixed reality technology to enhance dental implant surgery navigation. Our first step was reconstructing a virtual 3D model from pre-operative cone-beam CT (CBCT) images. We then obtained the relative position between objects using the navigation device and HoloLens camera. Via the algorithms of virtual-actual registration, the transformation matrixes between the HoloLens devices and the navigation tracker were acquired through the HoloLens-tracker registration, and the transformation matrixes between the virtual model and the patient phantom through the image-phantom registration. In addition, the algorithm of surgical drill calibration assisted in acquiring transformation matrixes between the surgical drill and the patient phantom. These algorithms allow real-time tracking of the surgical drill's location and orientation relative to the patient phantom under the navigation device. With the aid of the HoloLens 2, virtual 3D images and actual patient phantoms can be aligned accurately, providing surgeons with a clear visualization of the implant path.

RESULTS

Phantom experiments were conducted using 30 patient phantoms, with a total of 102 dental implants inserted. Comparisons between the actual implant paths and the pre-operatively planned implant paths showed that our system achieved a coronal deviation of 1.507 ± 0.155 mm, an apical deviation of 1.542 ± 0.143 mm, and an angular deviation of 3.468 ± 0.339°. The deviation was not significantly different from that of the navigation-guided dental implant placement but better than the freehand dental implant placement.

CONCLUSION

Our proposed system realizes the integration of the pre-operative planned dental implant paths and the patient phantom, which helps surgeons achieve adequate accuracy in traditional dental implant surgery. Furthermore, this system is expected to be applicable to animal and cadaveric experiments in further studies.

Systematic Review of Extended Reality Digital Therapy for Enhancing Mental Health Among South Korean Adolescents and Young Adults

Digital therapy using extended reality (XR) holds great promise for addressing the mental health needs of adolescents and young adults. This study addresses a notable research gap in South Korea by systematically reviewing XR-based digital therapy for the mental health of South Korean adolescents and young adults. We analyzed 26 studies encompassing various aspects, including study type, publication date, research field, research methodology, data sources, program types, program content, sample characteristics, target population, assessment tools, and program effectiveness. Notably, 46.15% of the studies employed an experimental design, whereas over 53% utilized non-experimental approaches. Experimental studies lacked a genuine design, standardized questionnaires, and control variables. Similarly, non-experimental studies failed to report specific literature selection criteria. Consequently, future studies should adopt rigorous methodologies to enhance reliability and validity. Moreover, over 85% of the 26 studies focused solely on virtual reality and did not incorporate augmented or mixed reality. This study identifies the limitations of the previous research. These findings emphasize the need for structured investigations to advance the development of XR-based digital therapy to promote mental health in adolescents and young adults in South Korea.

Merging virtual and physical experiences: extended realities in cardiovascular medicine

Technological advancement and the COVID-19 pandemic have brought virtual learning and working into our daily lives. Extended realities (XR), an umbrella term for all the immersive technologies that merge virtual and physical experiences, will undoubtedly be an indispensable part of future clinical practice. The intuitive and three-dimensional nature of XR has great potential to benefit healthcare providers and empower patients and physicians. In the past decade, the implementation of XR into cardiovascular medicine has flourished such that it is now integrated into medical training, patient education, pre-procedural planning, intra-procedural visualization, and post-procedural care. This review article discussed how XR could provide innovative care and complement traditional practice, as well as addressing its limitations and considering its future perspectives.

Virtual and augmented reality in intensive care medicine: a systematic review

BACKGROUND

Virtual reality (VR) and augmented reality (AR) are rapidly developing technologies that offer a wide range of applications and enable users to experience digitally rendered content in both physical and virtual space. Although the number of studies about the different use of VR and AR increases year by year, a systematic overview of the applications of these innovative technologies in intensive care medicine is lacking. The aim of this systematic review was to provide a detailed summary of how VR and AR are currently being used in various areas of intensive care medicine.

METHODS

We systematically searched PubMed until 1st March 2023 to identify the currently existing evidence for different applications of VR and AR for both health care providers in the intensive care unit and children or adults, who were in an intensive care unit because of a critical illness.

RESULTS

After screening the literature, a total of 59 studies were included. Of note, a substantial number of publications consists of case reports, study plans or are lacking a control group. Furthermore, study designs are seldom comparable. However, there have been a variety of use cases for VR and AR that researchers have explored. They can help intensive care unit (ICU) personnel train, plan, and perform difficult procedures such as cardiopulmonary resuscitation, vascular punctures, endotracheal intubation or percutaneous dilatational tracheostomy. Patients might benefit from VR during invasive interventions and ICU stay by alleviating stress or pain. Furthermore, it enables contact with relatives and can also assist patients in their rehabilitation programs.

CONCLUSION

Both, VR and AR, offer multiple possibilities to improve current care, both from the perspective of the healthcare professional and the patient. It can be assumed that VR and AR will develop further and their application in health care will increase.

A multi-view interactive virtual-physical registration method for mixed reality based surgical navigation in pelvic and acetabular fracture fixation

PURPOSE

The treatment of pelvic and acetabular fractures remains technically demanding, and traditional surgical navigation systems suffer from the hand-eye mis-coordination. This paper describes a multi-view interactive virtual-physical registration method to enhance the surgeon's depth perception and a mixed reality (MR)-based surgical navigation system for pelvic and acetabular fracture fixation.

METHODS

First, the pelvic structure is reconstructed by segmentation in a preoperative CT scan, and an insertion path for the percutaneous LC-II screw is computed. A custom hand-held registration cube is used for virtual-physical registration. Three strategies are proposed to improve the surgeon's depth perception: vertices alignment, tremble compensation and multi-view averaging. During navigation, distance and angular deviation visual cues are updated to help the surgeon with the guide wire insertion. The methods have been integrated into an MR module in a surgical navigation system.

RESULTS

Phantom experiments were conducted. Ablation experimental results demonstrated the effectiveness of each strategy in the virtual-physical registration method. The proposed method achieved the best accuracy in comparison with related works. For percutaneous guide wire placement, our system achieved a mean bony entry point error of 2.76 ± 1.31 mm, a mean bony exit point error of 4.13 ± 1.74 mm, and a mean angular deviation of 3.04 ± 1.22°.

CONCLUSIONS

The proposed method can improve the virtual-physical fusion accuracy. The developed MR-based surgical navigation system has clinical application potential. Cadaver and clinical experiments will be conducted in future.

Use of a mixed reality system for navigational mapping during cardiac electrophysiological testing does not prolong case duration: A subanalysis from the Cardiac Augmented REality study

Background

CommandEP™ is a mixed reality (MXR) system for cardiac electrophysiological (EP) procedures that provides a real-time 3-dimensional digital image of cardiac geometry and catheter locations. In a previous study, physicians using the system demonstrated improved navigational accuracy. This study investigated the impact of the CommandEP system on EP procedural times compared to the standard-of-care electroanatomic mapping system (EAMS) display.

Objective

The purpose of this retrospective case-controlled analysis was to evaluate the impact of a novel MXR interface on EP procedural times compared to a case-matched cohort.

Methods

Cases from the Cardiac Augmented REality (CARE) study were matched for diagnosis and weight using a contemporary cohort. Procedural time was compared from the roll-in and full implementation cohort. During routine EP procedures, operators performed tasks during the postablation waiting phase, including creation of cardiac geometry and 5-point navigation under 2 conditions: (1) EAMS first; and (2) CommandEP.

Results

From a total of 16 CARE study patients, the 10 full implementation patients were matched to a cohort of 20 control patients (2 controls:1 CARE, matched according to pathology and age/weight). No statistical difference in total case times between CARE study patients vs control group (118 ± 29 minutes vs 97 ± 20 minutes; P = .07) or fluoroscopy times (6 ± 4 minutes vs 7 ± 6 minutes; P = .9). No significant difference in case duration for CARE study patients comparing roll-in vs full-implementation cohort (121 ± 26 minutes vs 118 ± 29 minutes; P = .96). CommandEP wear time during cases was significantly longer in full implementation cases (53 ± 24 minutes vs 24 ± 5 minutes; P = .0009). During creation of a single cardiac geometry, no significant time difference was noted between CommandEP vs EAMS (284 ± 45 seconds vs 268 ± 43 seconds; P = .1) or fluoroscopy use (9 ± 19 seconds vs 6 ± 18 seconds; P = .25). During point navigation tasks, there was no difference in total time (CommandEP 31 ± 14 seconds vs EAMS 28 ± 15 seconds; P = .16) or fluoroscopy time (CommandEP 0 second vs EAMS 0 second).

Conclusion

MXR did not prolong overall procedural time compared to a matched cohort. There was no prolongation in study task completion time. Future studies with experienced CommandEP users directly assessing procedural time and task completion time in a randomized study population would be of interest.

Development and Evaluation of a Mixed-Reality Tele-ultrasound System

OBJECTIVE

The objective of this feasibility study was to develop and assess a tele-ultrasound system that would enable an expert sonographer (situated at the remote site) to provide real-time guidance to an operator (situated at the imaging site) using a mixed-reality environment.

METHODS

An architecture along with the operational workflow of the system is designed and a prototype is developed that enables guidance in form of audiovisual cues. The visual cues comprise holograms (of the ultrasound images and ultrasound probe) and is rendered to the operator using a head-mounted display device. The position and orientation of the ultrasound probe's hologram are remotely controlled by the expert sonographer and guide the placement of a physical ultrasound probe at the imaging site. The developed prototype was evaluated for its performance on a network. In addition, a user study (with 12 participants) was conducted to assess the operator's ability to align the probe under different guidance modes.

RESULTS

The network performance revealed the view of the imaging site and ultrasound images were transferred to the remote site in 233 ± 42 and 158 ± 38 ms, respectively. The expert sonographer was able to transfer, to the imaging site, data related to position and orientation of the ultrasound probe's hologram in 78 ± 13 ms. The user study indicated that the audiovisual cues are sufficient for an operator to position and orient a physical probe for accurate depiction of the targeted tissue (p < 0.001). The probe's placement translational and rotational errors were 1.4 ± 0.6 mm and 5.4 ± 2.2º.

CONCLUSION

The work illustrates the feasibility of using a mixed-reality environment for effective communication between an expert sonographer (ultrasound physician) and an operator. Further studies are required to determine its applicability in a clinical setting during tele-ultrasound.

Virtual Models Using Augmented Reality May Provide a Suitable Supplement, Although Not a Physical Specimen Replacement, in Pathology Education

There is a growing trend towards using virtual models within medical programs. In some disciplines, the use of human samples or cadavers is increasingly being replaced by technology-enhanced modes of delivery. Although this transition can occur with some success, the impact of virtual representations to replace depictions of disease states from dissected samples displayed in acrylic pathological specimen jars has never been investigated. This study assessed medical student perceptions of replacing teaching through physical specimens (i.e. specimen jars or real tissue) with virtual models across cardiovascular, neural, musculoskeletal, haematology, endocrine and immunological pathology curricula. Seventy-four year 2 (n = 31) and year 5 (n = 43) medical students participated in the study. After being provided with a demonstration of a potential tablet-based lesson on lung pathology using augmented reality, participants completed a Likert-scale survey and provided written feedback. Questions requested thoughts on the usefulness of the 3D-virtual model compared to physical specimens and whether current teaching in pathology could be replaced by technology-enhanced practices. Most students (58.15%) disagreed on the replacement of physical specimens with virtual models. Furthermore, over half the students (55.4%) indicated that the replacement of physical specimens with augmented reality models would not be beneficial for pathology learning. Nearly two-thirds of students believed that the absence of physical specimens would negatively impact their knowledge. Nonetheless, many students would appreciate the opportunity to revise pathology away from the labs with virtual options. As such, an overwhelming number of students (89.2%) would prefer having both physical specimens and virtual models for learning. This study identifies that technology-enhanced learning may be a suitable supplement alongside traditional hands-on teaching but should not replace the use of pathological specimens within a medical curriculum.

Mixed reality for the assessment of aortoiliac anatomy in patients with abdominal aortic aneurysm prior to open and endovascular repair: Feasibility and interobserver agreement

OBJECTIVES

The objective is to evaluate the feasibility and interobserver agreement of a Mixed Reality Viewer (MRV) in the assessment of aortoiliac vascular anatomy of abdominal aortic aneurysm (AAA) patients.

METHODS

Fifty preoperative computed tomography angiographies (CTAs) of AAA patients were included. CTAs were assessed in a mixed reality (MR) environment with respect to aortoiliac anatomy according to a standardized protocol by two experienced observers (Mixed Reality Viewer, MRV, Brainlab AG, Germany). Additionally, all CTAs were independently assessed applying the same protocol by the same observers using a conventional DICOM viewer on a two-dimensional screen with multi-planar reconstructions (Conventional viewer, CV, GE Centricity PACS RA1000 Workstation, GE, United States). The protocol included four sets of items: calcification, dilatation, patency, and tortuosity as well as the number of lumbar and renal arteries. Interobserver agreement (IA, Cohen's Kappa, κ) was calculated for every item set.

RESULTS

All CTAs could successfully be displayed in the MRV (100%). The MRV demonstrated equal or better IA in the assessment of anterior and posterior calcification (κMRV: 0.68 and 0.61, κCV: 0.33 and 0.45, respectively) as well as tortuosity (κMRV: 0.60, κCV: 0.48) and dilatation (κMRV: 0.68, κCV: 0.67). The CV demonstrated better IA in the assessment of patency (κMRV: 0.74, κCV: 0.93). The CV also identified significantly more lumbar arteries (CV: 379, MRV: 239, p < 0.01).

CONCLUSIONS

The MRV is a feasible imaging viewing technology in clinical routine. Future efforts should aim at improving hologram quality and enabling accurate registration of the hologram with the physical patient.

Mixed reality combined with ALPPS for colorectal liver metastases, a case report

INTRODUCTION

Improvement of treatments for patients suffering from colorectal carcinoma and extended liver metastases has increased the overall survival and enables more patients to undergo surgical therapy. If the future liver remnant (FLR) is expected to be low, Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy (ALPPS) is a potential treatment with high feasibility and an increase in overall survival. The evolving mixed reality technology could support hepatobiliary surgery. This case report demonstrates for the first time the combination of mixed reality technology and ALPPS procedure for a patient with low expected FLR.

PRESENTATION OF CASE

A 49-year-old patient is presented with adenocarcinoma of the caecum with bilateral liver metastasis. After colon resection, a palliative chemotherapy was administered with good response and partial remission, so curative liver resection was intended. Based on the low expected FLR, calculated from the 3D-model of the liver, we decided to perform an in-situ split resection supported by mixed reality intraoperatively. The total operation time was 6 + 2 h. During both steps no blood transfusion was required and no major complication occurred. The patient was discharged 15 days after the second step. Final pathology revealed multiple predominantly necrotic metastases of the pre-existing colon carcinoma (ypM1, R0).

DISCUSSION

After the first step of ALPPS, an increase of the FLR up to 57 % was achieved, so the second step was performed on postoperative day (POD)11. The 3D-model and the intraoperative use of mixed reality supported our decision making and intraoperative navigation. This technique could be implemented on a larger scale to support complex liver resections.

CONCLUSION

The combination of mixed reality with ALPPS resulted in a good surgical outcome and should be considered as a potential alternative for liver resections.

Use of Mixed Reality in Neurosurgery Training: A Single Centre Experience

BACKGROUND

Mixed reality (MR) technology has opened new avenues for planning, visualization, and education in surgery. Neurosurgical pathologies require a very clear understanding of the relationships between pathology and critical neurovascular structures. The decline in cadaveric dissections and resource constraints has pushed the educators to find newer ways of rendering the same knowledge. The aim of this study was to determine the feasibility of employing a MR device in a high-volume center for neurosurgical teaching. The study also evaluated the results of the trainee experience in using the MR platform.

METHODS

Three neurosurgical consultants who are part of the teaching faculty were asked to facilitate the session. No prior training on utilizing the MR device was given to the trainees. HoloLens 2 was used as the MR device. Two questionnaires were used to understand the experience of the trainees.

RESULTS

Eight active neurosurgical trainees who are currently training at our institution were recruited for the purposes of this study. Despite having no prior training on a MR platform, the learning curve was short for most of the trainees. Whether MR replace current traditional methods of teaching neuroanatomy, the response was divided across the trainees. The results of the User Experience Questionnaire were positive with the trainees finding the device as attractive, dependable, novel, and user-friendly.

CONCLUSION

This study demonstrates the feasibility of using MR platform in neurosurgery training without significant preparation requirements. These data are required to justify the future investment in this technology for training institutions.

An autonomous X-ray image acquisition and interpretation system for assisting percutaneous pelvic fracture fixation

PURPOSE

Percutaneous fracture fixation involves multiple X-ray acquisitions to determine adequate tool trajectories in bony anatomy. In order to reduce time spent adjusting the X-ray imager's gantry, avoid excess acquisitions, and anticipate inadequate trajectories before penetrating bone, we propose an autonomous system for intra-operative feedback that combines robotic X-ray imaging and machine learning for automated image acquisition and interpretation, respectively.

METHODS

Our approach reconstructs an appropriate trajectory in a two-image sequence, where the optimal second viewpoint is determined based on analysis of the first image. A deep neural network is responsible for detecting the tool and corridor, here a K-wire and the superior pubic ramus, respectively, in these radiographs. The reconstructed corridor and K-wire pose are compared to determine likelihood of cortical breach, and both are visualized for the clinician in a mixed reality environment that is spatially registered to the patient and delivered by an optical see-through head-mounted display.

RESULTS

We assess the upper bounds on system performance through in silico evaluation across 11 CTs with fractures present, in which the corridor and K-wire are adequately reconstructed. In post hoc analysis of radiographs across 3 cadaveric specimens, our system determines the appropriate trajectory to within 2.8 ± 1.3 mm and 2.7 ± 1.8[Formula: see text].

CONCLUSION

An expert user study with an anthropomorphic phantom demonstrates how our autonomous, integrated system requires fewer images and lower movement to guide and confirm adequate placement compared to current clinical practice. Code and data are available.

[Digital tools in musculoskeletal rehabilitation]

The demographic transition in combination with the increasing demands of society and a growing shortage of skilled workers are leading to a shortage of care in musculoskeletal rehabilitation, especially in times of the pandemic. Digital interventions represent an opportunity to reintegrate patients with musculoskeletal dysfunctions into everyday life. The changes to the legal basis enable physicians and therapists to support the rehabilitation of their patients with reimbursable apps and digital applications and to permanently integrate learned skills into their daily lives. Telerehabilitation technologies, apps, telerobotics and mixed reality offer the opportunity to complement and optimize existing care structures and to redesign specialized therapeutic home visits with modern technology in a new and contemporary way.

A systematic review of the application of immersive technologies for safety and health management in the construction sector

INTRODUCTION

The construction industry employs about 7% of global manpower and contributes about 6% to the global economy. However, statistics have depicted that the construction industry contributes significantly to workplace fatalities and injuries despite multiple interventions (including technological applications) implemented by governments and construction companies. Recently, immersive technologies as part of a suite of industry 4.0 technologies, have also strongly emerged as a viable pathway to help address poor construction occupational safety and health (OSH) performance.

METHOD

With the aim of gaining a broad view of different construction OSH issues addressed using immersive technologies, a review on the application of immersive technologies for construction OSH management is conducted using the preferred reporting items for systematic reviews and meta-analysis (PRISMA) approach and bibliometric analysis of literature. This resulted in the evaluation of 117 relevant papers collected from three online databases (Scopus, Web of Science, and Engineering Village).

RESULTS

The review revealed that literature have focused on the application of various immersive technologies for hazard identification and visualization, safety training, design for safety, risk perception, and assessment in various construction works. The review identified several limitations regarding the use of immersive technologies, which include the low level of adoption of the developed immersive technologies for OSH management by the construction industry, very limited research on the application of immersive technologies for health hazards, and limited focus on the comparison of the effectiveness of various immersive technologies for construction OSH management.

CONCLUSIONS AND PRACTICAL APPLICATIONS

For future research, it is recommended to identify possible reasons for the low transition level from research to industry practice and proffer solutions to the identified issues. Another recommendation is the study of the effectiveness of the use of immersive technologies for addressing health hazards in comparison to the conventional methods.

Movement kinematic and postural control differences when performing a visuomotor skill in real and virtual environments

Immersive technologies, like virtual and mixed reality, pose a novel challenge for our sensorimotor systems as they deliver simulated sensory inputs that may not match those of the natural environment. These include reduced fields of view, missing or inaccurate haptic information, and distortions of 3D space; differences that may impact the control of motor actions. For instance, reach-to-grasp movements without end-point haptic feedback are characterised by slower and more exaggerated movements. A general uncertainty about sensory input may also induce a more conscious form of movement control. We tested whether a more complex skill like golf putting was also characterized by more consciously controlled movement. In a repeated-measures design, kinematics of the putter swing and postural control were compared between (i) real-world putting, (ii) VR putting, and (iii) VR putting with haptic feedback from a real ball (i.e., mixed reality). Differences in putter swing were observed both between the real world and VR, and between VR conditions with and without haptic information. Further, clear differences in postural control emerged between real and virtual putting, with both VR conditions characterised by larger postural movements, which were more regular and less complex, suggesting a more conscious form of balance control. Conversely, participants actually reported less conscious awareness of their movements in VR. These findings highlight how fundamental movement differences may exist between virtual and natural environments, which may pose challenges for transfer of learning within applications to motor rehabilitation and sport.

The Effect of Holographic Heart Models and Mixed Reality for Anatomy Learning in Congenital Heart Disease: An Exploratory Study

In this paper, we present an exploratory study on the potential impact of holographic heart models and mixed reality technology on medical training, and in particular in teaching complex Congenital Heart Diseases (CHD) to medical students. Fifty-nine medical students were randomly allocated into three groups. Each participant in each group received a 30-minute lecture on a CHD condition interpretation and transcatheter treatment with different instructional tools. The participants of the first group attended a lecture in which traditional slides were projected onto a flat screen (group "regular slideware", RS). The second group was shown slides incorporating videos of holographic anatomical models (group "holographic videos", HV). Finally, those in the third group wore immersive, head-mounted devices (HMD) to interact directly with holographic anatomical models (group "mixed reality", MR). At the end of the lecture, the members of each group were asked to fill in a multiple-choice questionnaire aimed at evaluating their topic proficiency, as a proxy to evaluate the effectiveness of the training session (in terms of acquired notions); participants from group MR were also asked to fill in a questionnaire regarding the recommendability and usability of the MS Hololens HMDs, as a proxy of satisfaction regarding its use experience (UX). The findings show promising results for usability and user acceptance.

The Metaverse for Healthcare: Trends, Applications, and Future Directions of Digital Therapeutics for Urology

In recent years, the emergence of digital therapeutics as a novel approach to managing conditions has garnered significant attention. This approach involves using evidence-based therapeutic interventions that are facilitated by high-quality software programs to treat, manage, or prevent medical conditions. The incorporation of digital therapeutics into the Metaverse has increased the feasibility of their implementation and application in all areas of medical services. In urology, substantial digital therapeutics are being produced and researched, including mobile apps, bladder devices, pelvic floor muscle trainers, smart toilet systems, mixed reality-guided training and surgery, and training and telemedicine for urological consultations. The purpose of this review article is to provide a comprehensive overview of the current impact of the Metaverse on the field of digital therapeutics and identify its current trends, applications, and future perspectives in the field of urology.

Efficacy of exposure and response prevention therapy in mixed reality for patients with obsessive-compulsive disorder: study protocol for a randomized controlled trial

Many patients with obsessive-compulsive disorder (OCD) do not receive cognitive behavioral therapy with exposure and response prevention (first line treatment for OCD), for example, due to patients' fear of the exposure and reservations of the therapists. Technology-supported exposure (e.g., exposure therapy with response prevention in mixed reality [MERP]) for patients with OCD may help to overcome this obstacle. Building upon findings of our pilot study objectives of this study are to evaluate the efficacy, expectations of treatment success, feasibility, and acceptance of MERP as well as to identify possible limitations. In total, 64 outpatients with contamination-related OCD will be recruited and randomized to one of two conditions: MERP (six sessions in six weeks) and self-guided exposure therapy (six exercises in six weeks). Participants will be assessed before (baseline), after the six-week intervention period (post), as well as three months after post assessment (follow-up) regarding symptomatology (Yale-Brown Obsessive Compulsive Scale; Y-BOCS), their subjective evaluation of MERP (acceptance) and sense of presence. The planned study is the first to investigate MERP in patients with OCD.

Transanal lateral lymph node dissection with intraoperative hologram support in low rectal cancer

BACKGROUND

In Japan, the standard treatment for stage II/III advanced low rectal cancer is total mesorectal excision plus lateral lymph node dissection (LLND). There are also recent reports on the use of transanal LLND. However, the transanal anatomy is difficult to understand, and additional support tools are required to improve the surgical safety. The present study examined the utility of holograms with mixed reality as an intraoperative support tool for assessing the complex pelvic anatomy.

METHODS

Polygon (stereolithography) files of patients' pelvic organs were created and exported from the SYNAPSE VINCENT imaging system and uploaded into the Holoeyes MD virtual reality software. Three-dimensional images were automatically converted into patient-specific holograms. Each hologram was then installed into a head mount display (HoloLens2), and the surgeons and assistants wore the HoloLens2 when they performed transanal LLND. Twelve digestive surgeons with prior practice in hologram manipulation evaluated the utility of the intraoperative hologram support by means of a questionnaire.

RESULTS

Intraoperative hologram support improved the surgical understanding of the lateral lymph node region anatomy. In the questionnaire, 75% of the surgeons answered that the hologram accurately reflected the anatomy, and 92% of the surgeons answered that the anatomy was better understood by simulating the hologram intraoperatively than preoperatively. Moreover, 92% of the surgeons agreed that intraoperative holograms were a useful support tool for improving the surgical safety.

CONCLUSIONS

Intraoperative hologram support improved the surgical understanding of the pelvic anatomy for transanal LLND. Intraoperative holograms may represent a next-generation surgical tool for transanal LLND.

Student Perceptions of Superimposed Mixed Reality Anatomy: A Bridge Between the Virtual and Physical

A prototype mixed reality model was developed in which three-dimensional holograms of musculoskeletal anatomy were superimposed over a physical skeleton model, conferring tactile sensation to the bony attachments of virtually observed muscles. Fifty-three second-year medical students piloted this innovative format and provided feedback on its effectiveness as a learning modality.

Emerging Technologies in Shoulder Arthroplasty: Navigation, Mixed Reality, and Preoperative Planning

Shoulder arthroplasty is a rapidly improving and utilized management for end-stage arthritis that is associated with improved functional outcomes, pain relief, and long-term implant survival. Accurate placement of the glenoid and humeral components is critical for improved outcomes. Traditionally, preoperative planning was limited to radiographs and 2-dimensional computed tomography (CT); however, 3-dimensional CT is becoming more commonly utilized and necessary to understand complex glenoid and humeral deformities. To further increase accurate component placement, intraoperative assistive devices-patient-specific instrumentation, navigation, and mixed reality-minimize malpositioning, increase surgeon accuracy, and maximize fixation. These intraoperative technologies likely represent the future of shoulder arthroplasty.

A mixed-reality stimulator for lumbar puncture training: a pilot study

BACKGROUND

The simulation is one of the basic methods of medical education, which is often used for procedural skills training. However, the existing simulator lacks internal anatomical landmarks. The study developed a mixed-reality stimulator and evaluated its usability and feasibility in lumbar puncture training.

METHODS

The study recruited 40 subjects, including medical students, residents and faulty with varied levels of experience. Before training, participants completed the questionnaire about the basic information and watched a presentation about mixed reality. After practicing on mixed-reality stimulator, which provided internal anatomical structure, the examination was carried out and the results were documented. At the end of the training, trainees completed a survey of MR technology.

RESULTS

In this study, participants generally believed that the MR technology was very realistic (90%), and that the presentation of internal anatomy could help the operation (95%). Moreover, 72.5% and 75%, respectively, strongly agreed that the MR technology promoted learning and should be used in medical training. After this training, the success rate of puncture and the puncture time were significantly improved in experienced and non-experienced participants.

CONCLUSION

The existing simulator was easy to be transformed into MR simulator. This study showed the usability and feasibility of MR simulator in lumbar puncture training. As a potentially good tool to simulated medical skills training, next, MR technology would be developed and evaluated in more clinical skills teaching scenarios.

"Mixed Reality" in patient education prior to abdominal aortic aneurysm repair

Background: To investigate the usability of Mixed-Reality (MR) during patient education in patients scheduled for abdominal aortic aneurysm (AAA) repair. Patients and methods: Consecutive patients scheduled for elective AAA repair were block-randomized in either the Mixed-Reality group (MR group) or the conventional group (control group). Patients of both groups were educated about open and endovascular repair of their respective AAA. The MR group was educated using a head-mounted display (HMD) demonstrating a three-dimensional virtual reconstruction of the respective patient's vascular anatomy. The control group was educated using a conventional two-dimensional monitor to display the patient's vasculature. Outcomes were informational gain as well as patient satisfaction with the educational process. (DRKS-ID: DRKS00025174). Results: 50 patients were included with 25 patients in either group. Both groups demonstrated improvements in scores in the Informational Gain Questionnaire (IGQ) when comparing pre- and post-education scores. (MR group: 6.5 points (±1.8) versus 7.9 points (±1.5); Control group: 6.2 points (±1.8) versus 7.6 points (±1.6); p<0.01) There was no significant difference between the MR group and the control group either in informational gain (MR group: 1.4±1.8; Control group: 1.4±1.8; p=0.5) nor in patient satisfaction scores (MR group: mean 18.3 of maximum 21 points (±3.7); Control group: mean 17 of 21 points (±3.6); p=0.1) Multiple regression revealed no correlation between the use of MR and informational gain or patient satisfaction. Usability of the system was rated high, and patients' subjective assessment of MR was positive. Conclusions: The use of MR in patient education of AAA patients scheduled for elective repair is feasible. While patients reported positively on the use of MR in education, similar levels of informational gain and patient satisfaction can be achieved with MR and conventional methods.