Mild simulator sickness can alter heart rate variability, mental workload, and learning outcomes in a 360° virtual reality application for medical education: a post hoc analysis of a randomized controlled trial.

Virtual reality (VR) applications could be beneficial for education, training, and treatment. However, VR may induce symptoms of simulator sickness (SS) such as difficulty focusing, difficulty concentrating, or dizziness that could impair autonomic nervous system function, affect mental workload, and worsen interventional outcomes. In the original randomized controlled trial, which explored the effectiveness of using a 360° VR video versus a two-dimensional VR video to learn history taking and physical examination skills, only the former group participants had SS. Therefore, 28 undergraduate medical students who participated in a 360° VR learning module were included in this post hoc study using a repeated measures design. Data of the Simulator Sickness Questionnaire (SSQ), heart rate variability (HRV) analysis, Task Load Index, and Mini-Clinical Evaluation Exercise were retrospectively reviewed and statistically analyzed. Ten (36%) participants had mild SS (total score > 0 and ≤ 20), and 18 (64%) had no SS symptom. Total SSQ score was positively related to the very low frequency (VLF) band power, physical demand subscale, and frustration subscale, and inversely related to physical examination score. Using multilevel modeling, the VLF power mediated the relationship between total SSQ score and physical examination score. Furthermore, frustration subscale moderated the mediating effects of the VLF power. Our results highlight the importance of documenting SS to evaluate a 360° VR training program. Furthermore, the combination of HRV analysis with mental workload measurement and outcome assessments provided the important clinical value in evaluating the effects of SS in VR applications in medical education.

Intelligent HMI in Orthopedic Navigation.

The human-machine interface (HMI) is an essential part of image-guided orthopedic navigation systems. HMI provides a primary platform to merge surgically relevant pre- and intraoperative images from different modalities and 3D models including anatomical structures and implants to support surgical planning and navigation. With the various input-output techniques of HMI, surgeons can intuitively manipulate anatomical models generated from medical images and/or implant models for surgical planning. Furthermore, HMI recreates sight, sound, and touch feedback for the guidance of surgery operations which helps surgeons to sense more relevant information, e.g., anatomical structures and surrounding tissue, the mechanical axis of limbs, and even the mechanical properties of tissue. Thus, with the help of interactive HMI, precision operations, such as cutting, drilling, and implantation, can be performed more easily and safely.Classic HMI is based on 2D displays and standard input devices of computers. In contrast, modern visual reality (VR) and augmented reality (AR) techniques allow the showing more information for surgical navigation. Various attempts have been applied to image-guided orthopedic therapy. In order to realize rapid image-based modeling and to create effective interaction and feedback, intelligent algorithms have been developed. Intelligent algorithms can realize fast registration of image to image and image to patients, and the algorithms to compensate the visual offset in AR display have been investigated. In order to accomplish more effective human-computer interaction, various input methods and force sensing/force reflecting methods have been developed. This chapter reviews related human-machine interface techniques for image-guided orthopedic navigation, analyzes several examples of clinical applications, and discusses the trend of intelligent HMI in orthopedic navigation.

Effectiveness of balance training on pain and functional outcomes in knee osteoarthritis: A systematic review and meta-analysis.

Background: Knee osteoarthritis (OA) is a musculoskeletal disorder that causes pain and increasing loss of function, resulting in reduced proprioceptive accuracy and balance. Therefore, the goal of this systematic review and meta-analysis is to evaluate the effectiveness of balance training on pain and functional outcomes in knee OA. Methods: "PubMed", "Scopus", "Web of Science", "Cochrane", and "Physiotherapy Evidence Database" were searched for studies conducted between January 2000 and December 2021. Randomized controlled trials (RCTs) that investigated the effectiveness of balance training in knee OA, as well as its effects on pain and functional outcome measures, were included. Conference abstracts, case reports, observational studies, and clinical commentaries were not included. Meta-analysis was conducted for the common outcomes, i.e., Visual Analog Scale (VAS), The Timed Up and Go (TUG), Western Ontario and McMaster Universities Arthritis Index (WOMAC). The PEDro scale was used to determine the quality of the included studies. Results: This review includes 22 RCTs of which 17 articles were included for meta-analysis. The included articles had 1456 participants. The meta-analysis showed improvement in the VAS scores in the experimental group compared to the control group [ I 2= 92%; mean difference= -0.79; 95% CI= -1.59 to 0.01; p<0.05] and for the WOMAC scores the heterogeneity ( I 2) was 81% with a mean difference of -0.02 [95% CI= -0.44 to 0.40; p<0.0001]. The TUG score was analyzed, the I 2 was 95% with a mean difference of -1.71 [95% CI= -3.09 to -0.33; p<0.0001] for the intervention against the control group. Conclusions: Balance training significantly reduced knee pain and improved functional outcomes measured with TUG. However, there was no difference observed in WOMAC. Although due to the heterogeneity of the included articles the treatment impact may be overestimated. Registration: The current systematic review was registered in PROSPERO on 7th October 2021 (registration number CRD42021276674).

Emerging Limb Rehabilitation Therapy After Post-stroke Motor Recovery.

Stroke, including hemorrhagic and ischemic stroke, refers to the blood supply disorder in the local brain tissue for various reasons (aneurysm, occlusion, etc.). It leads to regional brain circulation imbalance, neurological complications, limb motor dysfunction, aphasia, and depression. As the second-leading cause of death worldwide, stroke poses a significant threat to human life characterized by high mortality, disability, and recurrence. Therefore, the clinician has to care about the symptoms of stroke patients in the acute stage and formulate an effective postoperative rehabilitation plan to facilitate the recovery in patients. We summarize a novel application and update of the rehabilitation therapy in limb motor rehabilitation of stroke patients to provide a potential future stroke rehabilitation strategy.

The Antarium: A Reconstructed Visual Reality Device for Ant Navigation Research.

We constructed a large projection device (the Antarium) with 20,000 UV-Blue-Green LEDs that allows us to present tethered ants with views of their natural foraging environment. The ants walk on an air-cushioned trackball, their movements are registered and can be fed back to the visual panorama. Views are generated in a 3D model of the ants' environment so that they experience the changing visual world in the same way as they do when foraging naturally. The Antarium is a biscribed pentakis dodecahedron with 55 facets of identical isosceles triangles. The length of the base of the triangles is 368 mm resulting in a device that is roughly 1 m in diameter. Each triangle contains 361 blue/green LEDs and nine UV LEDs. The 55 triangles of the Antarium have 19,855 Green and Blue pixels and 495 UV pixels, covering 360° azimuth and elevation from -50° below the horizon to +90° above the horizon. The angular resolution is 1.5° for Green and Blue LEDs and 6.7° for UV LEDs, offering 65,536 intensity levels at a flicker frequency of more than 9,000 Hz and a framerate of 190 fps. Also, the direction and degree of polarisation of the UV LEDs can be adjusted through polarisers mounted on the axles of rotary actuators. We build 3D models of the natural foraging environment of ants using purely camera-based methods. We reconstruct panoramic scenes at any point within these models, by projecting panoramic images onto six virtual cameras which capture a cube-map of images to be projected by the LEDs of the Antarium. The Antarium is a unique instrument to investigate visual navigation in ants. In an open loop, it allows us to provide ants with familiar and unfamiliar views, with completely featureless visual scenes, or with scenes that are altered in spatial or spectral composition. In closed-loop, we can study the behavior of ants that are virtually displaced within their natural foraging environment. In the future, the Antarium can also be used to investigate the dynamics of navigational guidance and the neurophysiological basis of ant navigation in natural visual environments.

Effect of laparoscopic visual reality training on the basic technical skill of laparoscopic operation / 中华医学教育探索杂志

Objective To explore the outcome of laparoscopic visual reality training in participants with different clinical experiences. Methods Clinical training doctors,advanced study doctors,intern doctors practiced peg transfer,cutting and making saturation and instrumental tie by using laparoscopic visual reality training,then made statistical analysis. The participants were trained for 2 weeks,90 min per day. The scores before and after the training in the 3 groups were recorded and compared. Results Before the training,the level of intern doctors on peg transfer、cutting and making saturation and instrumental tie was lower than the level of clinical training doctors and advanced study doctors(P0.05). The level of three different operators after training was obviously higher than that of themselves before training(P