Investigating Haptic Feedback in Vision-Deficient Millirobot Telemanipulation.

The evolution of magnetically actuated millirobots gives rise to unique teleoperation challenges due to their non-traditional kinematic and dynamic architectures, as well as their frequent use of suboptimal imaging modalities. Recent investigations into haptic interfaces for millirobots have shown promise but lack the clinically motivated task scenarios necessary to justify future development. In this work, we investigate the utility of haptic feedback on bilateral teleoperation of a magnetically actuated millirobot in visually deficient conditions. We conducted an N=23 user study in an aneurysm coiling inspired procedure, which required participants to navigate the robot through a maze in near total darkness to manipulate beads to a target under simulated fluoroscopy. We hypothesized that users will be better able to complete the telemanipulation task with haptic feedback while reducing excess forces on their surroundings compared to the no feedback conditions. Our results showed an over 40% improvement in participants' bead scoring, a nearly 10% reduction in mean force, and 13% reduction in maximum force with haptic feedback, as well as significant improvements in other metrics. Results highlight that benefits of haptic feedback are retained when haptic feedback is removed. These findings suggest that haptic feedback has the potential to significantly improve millirobot telemanipulation and control in traditionally vision deficient tasks.

Neural dynamics of delayed feedback in robot teleoperation: insights from fNIRS analysis.

Introduction: As robot teleoperation increasingly becomes integral in executing tasks in distant, hazardous, or inaccessible environments, operational delays remain a significant obstacle. These delays, inherent in signal transmission and processing, adversely affect operator performance, particularly in tasks requiring precision and timeliness. While current research has made strides in mitigating these delays through advanced control strategies and training methods, a crucial gap persists in understanding the neurofunctional impacts of these delays and the efficacy of countermeasures from a cognitive perspective. Methods: This study addresses the gap by leveraging functional Near-Infrared Spectroscopy (fNIRS) to examine the neurofunctional implications of simulated haptic feedback on cognitive activity and motor coordination under delayed conditions. In a human-subject experiment (N = 41), sensory feedback was manipulated to observe its influences on various brain regions of interest (ROIs) during teleoperation tasks. The fNIRS data provided a detailed assessment of cerebral activity, particularly in ROIs implicated in time perception and the execution of precise movements. Results: Our results reveal that the anchoring condition, which provided immediate simulated haptic feedback with a delayed visual cue, significantly optimized neural functions related to time perception and motor coordination. This condition also improved motor performance compared to the asynchronous condition, where visual and haptic feedback were misaligned. Discussion: These findings provide empirical evidence about the neurofunctional basis of the enhanced motor performance with simulated synthetic force feedback in the presence of teleoperation delays. The study highlights the potential for immediate haptic feedback to mitigate the adverse effects of operational delays, thereby improving the efficacy of teleoperation in critical applications.

HD-tDCS to the lateral occipital complex improves haptic object recognition.

High-definition transcranial direct current stimulation (HD-tDCS) is a non-invasive brain stimulation technique that has been shown to be safe and effective in modulating neuronal activity. The present study investigates the effect of anodal HD-tDCS on haptic object perception and memory through stimulation of the lateral occipital complex (LOC), a structure that has been shown to be involved in both visual and haptic object recognition. In this single-blind, sham-controlled, between-subjects study, blindfolded healthy, sighted participants used their right (dominant) hand to perform haptic discrimination and recognition tasks with 3D-printed, novel objects called "Greebles" while receiving 20 min of 2 milliamp (mA) anodal stimulation (or sham) to the left or right LOC. Compared to sham, those who received left LOC stimulation (contralateral to the hand used) showed an improvement in haptic object recognition but not discrimination-a finding that was evident from the start of the behavioral tasks. A second experiment showed that this effect was not observed with right LOC stimulation (ipsilateral to the hand used). These results suggest that HD-tDCS to the left LOC can improve recognition of objects perceived via touch. Overall, this work sheds light on the LOC as a multimodal structure that plays a key role in object recognition in both the visual and haptic modalities.

Mediated and non-mediated tactile fingerspelling: a comparative study.

In the development of communication devices for individuals who are Deafblind, a significant challenge is achieving a seamless transition from human-generated to technology-mediated communication. This study compares the intelligibility of the Australian Deafblind tactile fingerspelling alphabet rendered on the HaptiComm tactile communication device with the same alphabet articulated by a human signer. After a short training period, participants identified the 26 English alphabet letters in both the mediated (device) and non-mediated (human) conditions. Results indicated that while participants easily identified most letters in the non-mediated condition, the mediated condition was more difficult to decipher. Specifically, letters presented on the palm or near the index finger had significantly lower recognition rates. These findings highlight the need for further research on the tactile features of communication devices and emphasize the importance of refining these features to enhance the reliability and readability of mediated tactile communication produced through tactile fingerspelling.

Clinical Outcomes in Scleral Fixation Secondary Intraocular Lens with Yamane versus Suture Techniques: A Systematic Review and Meta-Analysis.

Background: The purpose of the study is to compare the visual outcomes and complications of sutured scleral fixation (SSF), a traditional and conservative surgical approach, and the newer and faster Yamane technique for secondary intraocular lens placement. Methods: A literature search was performed on PubMed, Embase, and Scopus on studies published between 1 July 2017 to 29 September 2023. Outcomes analyzed included the final best corrected visual acuity (BCVA) between 3 and 12 months to assess the effectiveness of the procedure, post-operative month (POM) 1 BCVA to assess the speed of visual recovery, endothelial cell count (ECC), absolute refractive error, surgical duration, and complication rates. Additional subgroup analyses were performed based on surgeon experience with the technique. Single-surgeon studies had an average of 26 procedures performed, whereas multiple-surgeon studies averaged only 9 procedures performed; these were then used to delineate surgeon experience. A sample-size weighted mean difference (MD) meta-analysis was performed across all variables using RevMan 5.4.1; p < 0.05 was considered statistically significant. Results: Thirteen studies with 737 eyes were included: 406 eyes were included in the SSF group, and 331 eyes were included in the Yamane group. There was no significant difference in the final BCVA between groups in both the single-surgeon versus multiple-surgeon studies (MD = -0.01, 95% CI: [-0.06, 0.04], p = 0.73). In the single-surgeon studies, the BCVA at POM1 was significantly improved in the Yamane group compared to SSF (MD = -0.10, 95% CI: [-0.16, -0.04], p = 0.002). In the multiple-surgeon studies, there was no significant difference in BCVA at POM1 (MD = -0.06, 95% CI: [-0.16, 0.04], p = 0.23). The Yamane group had a shorter surgical duration than SSF in both single-surgeon and multiple-surgeon studies (MD = -24.68, 95% CI: [-35.90, -13.46], p < 0.0001). The ECC, refractive error, and complication rates did not significantly differ amongst all groups. Conclusions: The Yamane technique demonstrated similar long-term visual outcomes and complication rates to the traditional SSF. Visual recovery was significantly faster in the Yamane group in the single-surgeon studies. The operative times were shorter across all Yamane groups. Based on these findings, it is advisable to consider the Yamane technique as a viable, and perhaps preferable, option for patients requiring secondary IOL placement, alongside traditional SSF methods.

Modified "C" Haptic Intraocular Lens Orientation and Negative Dysphotopsia.

Phacoemulsification is the standard of care in cataract surgery in the developed world, with patients having high expectations regarding visual results. Postoperative dissatisfaction due to negative dysphotopsia (ND) ranges from rare to very frequent; its etiology is unclear, and it affects postoperative satisfaction. Since one of the most frequently used strategies to avoid ND is related to intraocular lens (IOL) haptic orientation, we conducted a prospective interventional study that enrolled 197 patients who underwent standard phacoemulsification. All patients had a one-piece hydrophobic acrylic IOL implanted; in one group, the haptics were placed in any meridional axis except inferotemporal (IT) meridians, and in the other group, the IOL was implanted with the haptics in an IT position. Our results showed no statistically significant differences between groups when analyzing the correlation between the position of IOL haptics and the presence of ND in week one and month one. Also, pupillary diameter showed no statistically significant differences between patients with or without ND. Despite some studies claiming that haptic orientation prevents ND, we found that haptic orientation does not correlate with ND incidence and that ND decreases from day 1 to month 1. Our results support previous findings on the decrease in ND over time and that haptic orientation should not be considered an intraoperative strategy to avoid this unwanted phenomenon.

Clinical Assessment of Subjective Visual and Haptic Vertical Norms in Healthy Adults.

BACKGROUND AND OBJECTIVE: Accurate verticality perception is essential for daily life activities, such as correctly estimating object orientation in space. This study established normative data for the subjective visual vertical (SVV) and subjective haptic vertical (SHV) using the portable and self-constructable modified Bucket test and Rotating-Column test. Additionally, the contribution of age, sex, and starting position of the line/ column on SVV and SHV accuracy were evaluated. METHOD: This study, part of the PRECISE project (ClinicalTrials.gov ID NCT05978596), was conducted following the STROBE guidelines. Healthy adults without visual/neurological/vestibular disorders were recruited. Subjective visual vertical and SHV accuracy were described in terms of constant errors (i.e., mean deviation from 0° [true vertical] respecting its direction), unsigned errors (i.e., mean deviation from 0° irrespective of direction), and variability (i.e., intra-individual standard deviation). RESULTS: Sixty participants were evaluated (mean age: 41.14 [SD = 16.74] years). Subjective visual vertical constant errors between -2.82° and 2.90°, unsigned errors up to 2.15°, and variability up to 1.61° are considered normal. Subjective haptic vertical constant errors ranged from -6.94° to 8.18°, unsigned errors up to 6.66° and variability up to 4.25°. Higher ages led to higher SVV unsigned errors and variability. SHV variability was higher in females compared to males. Certain starting positions led to higher SVV and SHV constants and SVV unsigned errors. DISCUSSION: Normative data are provided for affordable, self-constructable, and portable SVV and SHV tools. These norms are consistent with more sophisticated equipment and can be used to distinguish between normal and abnormal values.

Advances in Piezoelectret Materials-Based Bidirectional Haptic Communication Devices.

Bidirectional haptic communication devices accelerate the revolution of virtual/augmented reality and flexible/wearable electronics. As an emerging kind of flexible piezoelectric materials, piezoelectret materials can effortlessly convert mechanical force into electrical signals and respond to electrical fields in a deformation manner, exhibiting enormous potential in the construction of bidirectional haptic communication devices. Existing reviews on piezoelectret materials primarily focus on flexible energy harvesters and sensors, and the recent development of piezoelectret-based bidirectional haptic communication devices has not been comprehensively reviewed. Herein, a comprehensive overview of the materials construction, along with the recent advances in bidirectional haptic communication devices, is provided. First, the development timeline, key characteristics, and various fabrication methods of piezoelectret materials are introduced. Subsequently, following the underlying mechanisms of bidirectional electromechanical signal conversion of piezoelectret, strategies to improve the d33 coefficients of materials are proposed. The principles of haptic perception and feedback are also highlighted, and representative works and progress in this area are summarized. Finally, the challenges and opportunities associated with improving the overall practicability of piezoelectret materials-based bidirectional haptic communication devices are discussed.

Development of neonatal Apgar scoring training program utilizing contactless hand tracking in immersive virtual reality.

BACKGROUND: The rapid and accurate assessment of neonatal asphyxia is critical to preventing potentially fatal outcomes. Therefore, nursing students must acquire the skills to assess newborn conditions immediately after birth and implement appropriate interventions. Virtual reality (VR) simulation education has emerged as a promising tool for nursing education, offering repetitive and customizable clinical training while ensuring patient safety and overcoming spatiotemporal limitations. AIM: This study investigated the effects of a contactless hand-tracking-based immersive VR neonatal Apgar scoring program, adapted from experiential learning theory. DESIGN: A non-randomized controlled trial with a pre-post-test, quasi-experimental design was conducted. SETTINGS: The study was conducted at two nursing schools from July to October 2023. PARTICIPANTS: Participants comprised nursing students holding bachelor's degrees in nursing, with three or four years of experience and successful completion of a neonatal nursing theory course. Additionally, individuals with at least six months of experience working in a neonatal ward or delivery room before enrolling in nursing school were eligible. METHODS: The participants were divided into three groups: the VR group (n = 27) received contactless hand-tracking-based immersive VR neonatal Apgar scoring training; the simulation group (n = 28) received face-to-face Apgar scoring simulation training; and the control group (n = 26) received instruction on the Apgar scoring criteria. Changes in scores among the VR, simulation, and control groups were statistically compared using ANOVA with SPSS-WIN 27.0. RESULTS: The VR group exhibited significant improvements in knowledge, learning satisfaction, self-confidence, immersion, and motivation compared to the simulation and control groups. Moreover, satisfaction was significantly higher in the VR group than in the simulation group. CONCLUSIONS: The hand-tracking-based immersive VR neonatal Apgar scoring program represents an innovative and effective educational tool, prioritizing the privacy and rights of mothers and infants. It can potentially replace traditional delivery-room clinical training, which is observation-based and limited.

Biosymbiotic haptic feedback - Sustained long term human machine interfaces.

Haptic technology permeates diverse fields and is receiving renewed attention for VR and AR applications. Advances in flexible electronics, facilitate the integration of haptic technologies into soft wearable systems, however, because of small footprint requirements face challenges of operational time requiring either large batteries, wired connections or frequent recharge, restricting the utility of haptic devices to short-duration tasks or low duty cycles, prohibiting continuously assisting applications. Currently many chronic applications are not investigated because of this technological gap. Here, we address wireless power and operation challenges with a biosymbiotic approach enabling continuous operation without user intervention, facilitated by wireless power transfer, eliminating the need for large batteries, and offering long-term haptic feedback without adhesive attachment to the body. These capabilities enable haptic feedback for robotic surgery training and posture correction over weeks of use with neural net computation. The demonstrations showcase that this device class expands use beyond conventional brick and strap or epidermally attached devices enabling new fields of use for imperceptible therapeutic and assistive haptic technologies supporting care and disease management.

Multisensory Extended Reality Applications Offer Benefits for Volumetric Biomedical Image Analysis in Research and Medicine.

3D data from high-resolution volumetric imaging is a central resource for diagnosis and treatment in modern medicine. While the fast development of AI enhances imaging and analysis, commonly used visualization methods lag far behind. Recent research used extended reality (XR) for perceiving 3D images with visual depth perception and touch but used restrictive haptic devices. While unrestricted touch benefits volumetric data examination, implementing natural haptic interaction with XR is challenging. The research question is whether a multisensory XR application with intuitive haptic interaction adds value and should be pursued. In a study, 24 experts for biomedical images in research and medicine explored 3D medical shapes with 3 applications: a multisensory virtual reality (VR) prototype using haptic gloves, a simple VR prototype using controllers, and a standard PC application. Results of standardized questionnaires showed no significant differences between all application types regarding usability and no significant difference between both VR applications regarding presence. Participants agreed to statements that VR visualizations provide better depth information, using the hands instead of controllers simplifies data exploration, the multisensory VR prototype allows intuitive data exploration, and it is beneficial over traditional data examination methods. While most participants mentioned manual interaction as the best aspect, they also found it the most improvable. We conclude that a multisensory XR application with improved manual interaction adds value for volumetric biomedical data examination. We will proceed with our open-source research project ISH3DE (Intuitive Stereoptic Haptic 3D Data Exploration) to serve medical education, therapeutic decisions, surgery preparations, or research data analysis.

Feeling of pulsations in artificial arteries with a real time haptic feedback laparoscopic grasper: a validation study.

INTRODUCTION: Despite the advancements in technology and organized training for surgeons in laparoscopic surgery, the persistent challenge of not being able to feel the resistance and characteristics of the tissue, including pulsations, remains unmet. A recently developed grasper (Optigrip®) with real time haptic feedback, based on photonic technology, aims to address this issue by restoring the tactile sensation for surgeons. The key question is whether pulsations can be detected and at what minimal size level they become clinical significant. METHODS: To simulate arterial conditions during laparoscopic procedures, four different silicone tubes were created, representing the most prevalent arteries. These tubes were connected to a validated pressure system, generating a natural pulse ranging between 80 and 120 mm Hg. One control tube without pressure was added. The surgeons had to grasp these tubes blindly with the conventional grasper or the haptic feedback grasper in a randomized order. They then indicated whether they felt the pressure or not and the percentage of correct answers was calculated. RESULTS: The haptic grasper successfully detected 96% of all pulsations, while the conventional grasper could only detect 6%. When considering the size of the arteries, the Optigrip® identified pulsations in 100% the 4 and 5 mm arteries and 92% of the smallest arteries. The conventional grasper was only able to feel the smallest arteries in 8%. These differences were highly significant (p < 0.0001). CONCLUSION: This study demonstrated that the newly developed haptic feedback grasper enables detection of arterial pulsations during laparoscopy, filling an important absence in tactile perception within laparoscopic surgery.

The value of stereoscopic three-dimensional vision on dental students' performance in a virtual reality simulator.

PURPOSE/OBJECTIVES: The aim of this study was to quantitatively investigate the impact of stereoscopic three-dimensional (3D) vision on students' performance when compared with that of two-dimensional (2D) vision in a 3D virtual reality (VR) simulator. METHODS: Twenty-four dental students (second- and fourth-year BDS) were assigned to perform three operative tasks under 3D and 2D viewing conditions on a Virteasy (HRV) simulator. Groups were crossed over and all students performed the same tasks under the alternate viewing conditions. The performance was evaluated by (1) accuracy, (2) outside target area removal, and (3) tooth cutting time, automatically using the generated feedback. RESULTS: Twenty-one participants completed all sessions. The results revealed a statistically significant effect of 3D vision over 2D vision on students' performance in terms of accuracy (p = 0.035). Stereoscopic 3D vision showed significant effect on outside target area removal in the first task (p = 0.035). Tooth cutting time was the same under both conditions (p = 0.766). The findings revealed improvement in accuracy score and reduction in outside target area removal over the course of the experiment under both conditions. Comparing the difference in 3D effect in the early and advanced learning groups revealed no significant difference among the groups (p > 0.05). CONCLUSION: Utilizing stereoscopic 3D vision in the training session improved students' perception of depth which led to more accurate tooth cutting within the target area, and less outside target area removal. However, 3D shows a limited impact on task completion time.

A Lightweight and Affordable Wearable Haptic Controller for Robot-Assisted Microsurgery.

In robot-assisted microsurgery (RAMS), surgeons often face the challenge of operating with minimal feedback, particularly lacking in haptic feedback. However, most traditional desktop haptic devices have restricted operational areas and limited dexterity. This report describes a novel, lightweight, and low-budget wearable haptic controller for teleoperated microsurgical robotic systems. We designed a wearable haptic interface entirely made using off-the-shelf material-PolyJet Photopolymer, fabricated using liquid and solid hybrid 3D co-printing technology. This interface was designed to resemble human soft tissues and can be wrapped around the fingertips, offering direct contact feedback to the operator. We also demonstrated that the device can be easily integrated with our motion tracking system for remote microsurgery. Two motion tracking methods, marker-based and marker-less, were compared in trajectory-tracking experiments at different depths to find the most effective motion tracking method for our RAMS system. The results indicate that within the 4 to 8 cm tracking range, the marker-based method achieved exceptional detection rates. Furthermore, the performance of three fusion algorithms was compared to establish the unscented Kalman filter as the most accurate and reliable. The effectiveness of the wearable haptic controller was evaluated through user studies focusing on the usefulness of haptic feedback. The results revealed that haptic feedback significantly enhances depth perception for operators during teleoperated RAMS.

Telepresence augmentation for visual and haptic guided immersive teleoperation of industrial manipulator.

Teleoperation under human guidance has become an effective solution to extend human's reach in various environments. However, the teleoperation system still faces challenges of insufficient sense of both visual and haptic feedback from remote environments, which results in the inadequate guidance for the operator. In this paper, a visual/haptic integrated perception and reconstruction system (VHI-PRS) is developed to provide the operator with 3D visual information and effective haptic guidance. Specifically, a visual-based telepresence augmentation method is proposed to provide the operator with virtual-reality combined visual telepresence, where the real point cloud model is directly superimposed on virtual manipulator to avoid the time-consuming process of mesh model rendering. With the utilization of visual information, a haptic-based telepresence augmentation method is proposed to provide the operator with comprehensive force feedback, including the virtual guiding force, virtual repulsive force and real-time interactive force, which greatly helps reduce the workload of operator. Finally, a user study on grab-place task is carried out to verify the effectiveness of proposed system.

Virtual dynamic interaction games reveal impaired multisensory integration in women with migraine.

OBJECTIVE: In this cross-sectional observational study, we aimed to investigate sensory profiles and multisensory integration processes in women with migraine using virtual dynamic interaction systems. BACKGROUND: Compared to studies on unimodal sensory processing, fewer studies show that multisensory integration differs in patients with migraine. Multisensory integration of visual, auditory, verbal, and haptic modalities has not been evaluated in migraine. METHODS: A 12-min virtual dynamic interaction game consisting of four parts was played by the participants. During the game, the participants were exposed to either visual stimuli only or multisensory stimuli in which auditory, verbal, and haptic stimuli were added to the visual stimuli. A total of 78 women participants (28 with migraine without aura and 50 healthy controls) were enrolled in this prospective exploratory study. Patients with migraine and healthy participants who met the inclusion criteria were randomized separately into visual and multisensory groups: Migraine multisensory (14 adults), migraine visual (14 adults), healthy multisensory (25 adults), and healthy visual (25 adults). The Sensory Profile Questionnaire was utilized to assess the participants' sensory profiles. The game scores and survey results were analyzed. RESULTS: In visual stimulus, the gaming performance scores of patients with migraine without aura were similar to the healthy controls, at a median (interquartile range [IQR]) of 81.8 (79.5-85.8) and 80.9 (77.1-84.2) (p = 0.149). Error rate of visual stimulus in patients with migraine without aura were comparable to healthy controls, at a median (IQR) of 0.11 (0.08-0.13) and 0.12 (0.10-0.14), respectively (p = 0,166). In multisensory stimulation, average gaming score was lower in patients with migraine without aura compared to healthy individuals (median [IQR] 82.2 [78.8-86.3] vs. 78.6 [74.0-82.4], p = 0.028). In women with migraine, exposure to new sensory modality upon visual stimuli in the fourth, seventh, and tenth rounds (median [IQR] 78.1 [74.1-82.0], 79.7 [77.2-82.5], 76.5 [70.2-82.1]) exhibited lower game scores compared to visual stimuli only (median [IQR] 82.3 [77.9-87.8], 84.2 [79.7-85.6], 80.8 [79.0-85.7], p = 0.044, p = 0.049, p = 0.016). According to the Sensory Profile Questionnaire results, sensory sensitivity, and sensory avoidance scores of patients with migraine (median [IQR] score 45.5 [41.0-54.7] and 47.0 [41.5-51.7]) were significantly higher than healthy participants (median [IQR] score 39.0 [34.0-44.2] and 40.0 [34.0-48.0], p < 0.001, p = 0.001). CONCLUSION: The virtual dynamic game approach showed for the first time that the gaming performance of patients with migraine without aura was negatively affected by the addition of auditory, verbal, and haptic stimuli onto visual stimuli. Multisensory integration of sensory modalities including haptic stimuli is disturbed even in the interictal period in women with migraine. Virtual games can be employed to assess the impact of sensory problems in the course of the disease. Also, sensory training could be a potential therapy target to improve multisensory processing in migraine.

Haptic and visuo-haptic impairments for object recognition in children with autism spectrum disorder: focus on the sensory and multisensory processing dysfunctions.

Dysfunctions in sensory processing are widely described in individuals with autism spectrum disorder (ASD), although little is known about the developmental course and the impact of these difficulties on the learning processes during the preschool and school ages of ASD children. Specifically, as regards the interplay between visual and haptic information in ASD during developmental age, knowledge is very scarce and controversial. In this study, we investigated unimodal (visual and haptic) and cross-modal (visuo-haptic) processing skills aimed at object recognition through a behavioural paradigm already used in children with typical development (TD), with cerebral palsy and with peripheral visual impairments. Thirty-five children with ASD (age range: 5-11 years) and thirty-five age-matched and gender-matched typically developing peers were recruited. The procedure required participants to perform an object-recognition task relying on only the visual modality (black-and-white photographs), only the haptic modality (manipulation of real objects) and visuo-haptic transfer of these two types of information. Results are consistent with the idea that visuo-haptic transfer may be significantly worse in ASD children than in TD peers, leading to significant impairment in multisensory interactions for object recognition facilitation. Furthermore, ASD children tended to show a specific deficit in haptic information processing, while a similar trend of maturation of visual modality between the two groups is reported. This study adds to the current literature by suggesting that ASD differences in multisensory processes also regard visuo-haptic abilities necessary to identify and recognise objects of daily life.

Haptic curing with endolaser after lens tilt in the Yamane technique.

Purpose: To describe a case of intraocular lens (IOL) tilt following transscleral IOL fixation with the Yamane technique and subsequent correction of tilt using 810-nm endoscopic diode laser. Observations: Our patient required lens exchange and secondary IOL implantation due to a dislocated 1-piece IOL in the bag causing iris chafe. After routine IOL fixation with the Yamane technique and a Zeiss CT Lucia 602 lens, the IOL tilted significantly in the immediate postoperative period. The lens tilt was subsequently corrected in the operating room using endolaser to melt and reshape (cure) the optic-haptic junction. Conclusions: IOL tilt is a known complication associated with the Yamane technique, which has seen increasing reports with the Zeiss CT Lucia 602 lens. Using endolaser to reconfigure the tilted optic into the desired orientation is a more novel procedure that can correct the lens tilt without the need for IOL exchange.

Perceptually Inspired C0-Continuity Haptic Shape Display with Trichamber Soft Actuators.

Shape display devices composed of actuation pixels enable dynamic rendering of surface morphological features, which have important roles in virtual reality and metaverse applications. The traditional pin-array solution produces sidestep-like structures between neighboring pins and normally relies on high-density pins to obtain curved surfaces. It remains a challenge to achieve continuous curved surfaces using a small number of actuated units. To address the challenge, we resort to the concept of surface continuity in computational geometry and develop a C0-continuity shape display device with trichamber fiber-reinforced soft actuators. Each trichamber unit produces three-dimensional (3D) deformation consisting of elongation, pitch, and yaw rotation, thus ensuring rendered surface continuity using low-resolution actuation units. Inspired by human tactile discrimination threshold on height and angle gradients between adjacent units, we proposed the mathematical criteria of C0-continuity shape display and compared the maximal number of distinguishable shapes using the proposed device in comparison with typical pin-array. We then established a shape control model considering the nonlinearity of soft materials to characterize and control the soft device to display C0-continuity shapes. Experimental results showed that the proposed device with nine trichamber units could render typical sets of distinguishable C0-continuity shape sequence changes. We envision that the concept of C0-continuity shape display with 3D deformation capability could improve the fidelity of the rendered shapes in many metaverse scenarios such as touching human organs in medical palpation simulations.

The application of virtual reality and augmented reality in dentistry - a literature review.

In recent times, dentistry has seen significant technological advancements that have transformed various specialized areas within the field. Developed into applications for mobile devices, augmented reality (AR) seamlessly merges digital components with the physical world, enhancing both realms while maintaining their individual separateness. On the other hand, virtual reality (VR) relies on advanced, tailored software to visualize a digital 3D environment stimulating the operator's senses through computer generated sensations and feedback. The current advances use the application of VR, haptic simulators, the use of an AI algorithm and many more that provides new opportunities for smart learning and enhance the teaching environment. As this technology continues to evolve, it is poised to become even more remarkable, enabling specialists to potentially visualize both soft and hard tissues within the patient's body for effective treatment planning. This literature aims to present the newest advancements and ongoing development of AR and VR in dentistry and medicine. It highlights their diverse applications while identifying areas needing further research for effective integration into clinical practice.