Search Results (835)

Natural and unconstrained locomotion remains a fundamental challenge in creating truly immersive virtual reality (VR) experiences. This paper presents the design and control of a novel robotic omnidirectional treadmill (ODT) based on the bilateral symmetry of two cooperative five-bar planar mechanisms designed to replicate realistic walking mechanics. The central contribution is a human in the loop control strategy designed to achieve stable walking in place. This framework employs a specific control strategy that actively repositions the footplates along a dynamically defined ‘Line of Movement’ (LoM), compensating for the user’s motion to ensure the midpoint between the feet remains stabilized and symmetrical at the platform’s geometric center. A comprehensive dynamic model of both the ODT and a coupled humanoid robot was developed to validate the system. Numerical simulations demonstrate robust performance across various gaits, including turning and catwalks, maintaining the user’s locomotion center with a maximum resultant drift error of 11.65 cm, a peak value that occurred momentarily during a turning motion and remained well within the ODT’s safe operational boundaries, with peak errors along any single axis remaining below 9 cm. The system operated with notable efficiency, requiring RMS torques below 22 Nm for the primary actuators. This work establishes a viable dynamic and control architecture for foot-tracking ODTs, paving the way for future enhancements such as haptic terrain feedback and elevation simulation. Full article

The VR-based circular tracking movement evaluation system (CES) was developed to quantitatively assess visuomotor control. The virtual stick, a component of the CES, provides visual cues in the virtual environment and haptic feedback when holding the controller. This study examined the effects of stick presence and presentation order on control accuracy for distance, angle, and angular velocity. Twenty-seven participants (12 females; mean age 23.3 ± 2.3 years) performed tasks in the frontal plane followed by the sagittal plane. In each plane, the stick was visible for the first 1–3 revolutions and invisible for the subsequent 4–6 revolutions in the invisible condition, with the reverse order in the visible condition. In the invisible condition, control accuracy with the stick was 1.10 times higher for distance only in the sagittal plane, and 1.13 and 1.09 times higher for angle and angular velocity in the frontal plane, and 1.11 and 1.08 times higher in the sagittal plane. No significant differences were observed in the visible condition. The improved control accuracy when the stick was visible is likely due to enhanced precision in constructing the reference frame, internal models, body coordinates, and effective multisensory integration of visual and haptic information. Such visual information may enable fine control in virtual environment-based applications, including games and surgical simulations. Full article

Vibrotactile stimulation has applications in a variety of fields, including medicine, virtual reality, and human–computer interaction. Eccentric Rotating Mass (ERM) vibrating motors are widely used in wearable haptic devices owing to their small size, low cost, and low-energy features. User experience with vibrotactile stimulation is an important factor in ergonomic design for these applications. The effects of ERM motor vibrations on upper-extremity sensation and perception, which are important in the design of better wearable haptic devices, have not been thoroughly studied previously. Our study focuses on the relationship between user sensation and perception and on different vibration parameters, including frequency, location, and number of motors. We conducted experiments with vibrotactile stimulation on 15 healthy participants while the subjects were both at rest and in motion to capture different use cases of haptic devices. Eight motors were placed on a consistent set of muscles in the subjects’ upper extremities, and one motor was placed on their index fingers. We found a significant correlation between voltage and sensation intensity (r = 0.39). This finding is important in the design and safety of customized haptic devices. However, we did not find a significant aggregate-level correlation with the perceived pleasantness of the simulation. The sensation intensity varied based on the location of the vibration on the upper extremities (with the lowest intensities on the triceps brachii and brachialis) and slightly decreased (5.9 ± 2.9%) when the participants performed reaching movements. When a single motor was vibrating, the participants’ accuracy in identifying the motor without visual feedback increased as the voltage increased, reaching up to 81.4 ± 14.2%. When we stimulated three muscles simultaneously, we found that most participants were able to identify only two out of three vibrating motors (41.7 ± 32.3%). Our findings can help identify stimulation parameters for the ergonomic design of haptic devices. Full article

Unrecognized mechanical faults and emergency sounds in vehicles can compromise safety, particularly for individuals with hearing impairments and in sound-insulated or autonomous driving environments. As intelligent transportation systems (ITSs) evolve, there is a growing need for inclusive, non-intrusive, and real-time diagnostic solutions that enhance situational awareness and accessibility. This study introduces an interpretable, sound-based machine learning framework to detect vehicle faults and emergency sound events using acoustic signals as a scalable diagnostic source. Three purpose-built datasets were developed: one for vehicular fault detection, another for emergency and environmental sounds, and a third integrating both to reflect real-world ITS acoustic scenarios. Audio data were preprocessed through normalization, resampling, and segmentation and transformed into numerical vectors using Mel-Frequency Cepstral Coefficients (MFCCs), Mel spectrograms, and Chroma features. To ensure performance and interpretability, feature selection was conducted using SHAP (explainability), Boruta (relevance), and ANOVA (statistical significance). A two-phase experimental workflow was implemented: Phase 1 evaluated 15 classical models, identifying ensemble classifiers and multi-layer perceptrons (MLPs) as top performers; Phase 2 applied advanced feature selection to refine model accuracy and transparency. Ensemble models such as Extra Trees, LightGBM, and XGBoost achieved over 91% accuracy and AUC scores exceeding 0.99. SHAP provided model transparency without performance loss, while ANOVA achieved high accuracy with fewer features. The proposed framework enhances accessibility by translating auditory alarms into visual/haptic alerts for hearing-impaired drivers and can be integrated into smart city ITS platforms via roadside monitoring systems. Full article

This research presents a preliminary proposal for a rehabilitation exercise aimed at patients with muscle weakness in the distal upper limb. A virtual environment was developed, where the user engages in a rehabilitation activity focused on rehabilitating the pinch grip. The goal is to strengthen the patient’s grasp and reduce muscle weakness. The virtual environment was designed as a video game in order to generate greater interest and encourage patients to adhere to their rehabilitation activities. This virtual game utilizes the haptic device Novint Falcon for the interaction with the environment. This preliminary work implements an impedance control with neural compensation; the control strategy produces signals to adapt the force exerted by the patient, with the goal that the device can give a force of the same magnitude but in the opposite direction. Consequently, regardless of the patient’s initial strength, the device will always deliver an assistive force to guide the patient along a desired trajectory. Initial experimental results with the proposed virtual-haptic rehabilitation system are presented, indicating the feasibility of the approach; however, further studies are required to validate its clinical effectiveness. Full article

Robotic surgery has become a cornerstone of modern urologic practice, with the da Vinci system maintaining dominance for over two decades. In recent years, however, a new generation of robotic platforms has emerged, introducing greater competition and innovation into the field. These systems aim to address unmet needs through features such as modular architectures, enhanced ergonomics, haptic feedback, and cost-containment strategies. Several platforms—including Hugo™ RAS, Versius™, Avatera™, REVO-I, Hinotori™, Senhance™, KangDuo, MicroHand S, Dexter™, and Toumai^®—have entered clinical use with early results demonstrating perioperative and short-term oncologic outcomes broadly comparable to those of established systems, particularly in procedures such as radical prostatectomy, partial nephrectomy, and radical cystectomy. At the same time, they introduce unique advantages in workflow flexibility, portability, and economic feasibility. Nevertheless, important challenges remain, including the need for rigorous comparative trials, standardized training curricula, and long-term cost-effectiveness analyses. The integration of artificial intelligence, augmented reality, and telesurgery holds the potential to further expand the role of robotics in urology, offering opportunities to enhance precision, improve accessibility, and redefine perioperative care models. This review summarizes the evolving landscape of robotic platforms in urology, highlights their clinical applications and limitations, and outlines future directions for research, training, and global implementation. Full article

The evolution of Human–Computer Interaction (HCI) has laid the foundation for more immersive and dynamic forms of communication between humans and machines. Building on this trajectory, this work introduces a significant advancement in the domain of Human–Robot Manipulation (HRM), particularly in the remote operation of humanoid robots in complex scenarios. We propose the Advanced Manipulation Assistant System (AMAS), a novel manipulation method designed to be low cost, low latency, and highly efficient, enabling real-time, precise control of humanoid robots from a distance. This method addresses critical challenges in current teleoperation systems, such as delayed response, expensive hardware requirements, and inefficient data transmission. By leveraging lightweight communication protocols, optimized sensor integration, and intelligent motion mapping, our system ensures minimal lag and accurate reproduction of human movements in the robot counterpart. In addition to these advantages, AMAS integrates multimodal feedback combining visual and haptic cues to enhance situational awareness, close the control loop, and further stabilize teleoperation. This transition from traditional HCI paradigms to advanced HRM reflects a broader shift toward more embodied forms of interaction, where human intent is seamlessly translated into robotic action. The implications are far-reaching, spanning applications in remote caregiving, hazardous environment exploration, and collaborative robotics. AMAS represents a step forward in making humanoid robot manipulation more accessible, scalable, and practical for real-world deployment. Full article

With the advancement of haptic technology, the use of pseudo-haptics to provide tactile feedback without physical contact has garnered significant attention. This paper aimed to investigate whether sliding fingers over onomatopoetic text strings with pseudo-haptic effects induces change in perception toward their symbolic semantics. To address this, we conducted an experiment using finger-point reading as our subject matter. The experimental results confirmed that the “neba-neba,” “puru-puru,” and “fusa-fusa” effects create a pseudo-haptic feeling for the associated texts on the “hard–soft,” “slippery–sticky,” and “elastic–inelastic” adjective pairs. Specifically, for “hard–soft,” it was found that the proposed effects could consistently produce an impact. Full article

Motion perception is a fundamental function of the tactile system, essential for object exploration and manipulation. While human studies have largely focused on discrete or pulsed stimuli with staggered onsets, many natural tactile signals are continuous and rhythmically patterned. Here, we investigate whether phase differences between “simultaneously” presented, “continuous” amplitude-modulated vibrations can induce the perception of motion across fingertips. Participants reliably perceived motion direction at modulation frequencies up to 1 Hz, with discrimination performance systematically dependent on the phase lag between vibrations. Critically, trial-level confidence reports revealed the lowest certainty for anti-phase (180°) conditions, consistent with stimulus ambiguity as predicted by the mathematical framework. I propose two candidate computational mechanisms for tactile motion processing. The first is a conventional cross-correlation computation over the envelopes; the second is a probabilistic model based on the uncertain detection of temporal reference points (e.g., envelope peaks) within threshold-defined windows. This model, despite having only a single parameter (uncertainty width determined by an amplitude discrimination threshold), accounts for both the non-linear shape and asymmetries of observed psychometric functions. These results demonstrate that the human tactile system can extract directional information from distributed phase-coded signals in the absence of spatial displacement, revealing a motion perception mechanism that parallels arthropod systems but potentially arises from distinct perceptual constraints. The findings underscore the feasibility of sparse, phase-coded stimulation as a lightweight and reproducible method for conveying motion cues in wearable, motion-capable haptic devices. Full article

Background and Objectives: Laparoscopic surgery has evolved with the integration of robotic systems, offering enhanced precision and ergonomic benefits. However, conventional robotic systems often lack haptic feedback and are associated with high cost. The Saroa surgical system is a compact, pneumatically driven robot that integrates real-time haptic feedback, potentially addressing the limitations associated with conventional robotic systems. This preliminary study reports the first clinical use of the Saroa system in gynecologic surgery, aiming to assess its feasibility, safety, and usability in robot-assisted hysterectomy. Materials and Methods: Five patients underwent robot-assisted total laparoscopic hysterectomy using the Saroa surgical system. The clinical outcomes, setup and console times, estimated blood loss, and subjective surgeon evaluation were recorded. Results: All surgeries were successfully completed without any intraoperative complications or the need for conversion to conventional surgery. The median setup time was 12 min, the console time was 211 min, and the median blood loss was 80 mL. Surgeons subjectively noted that the system’s real-time haptic feedback substantially improved precision during vaginal cuff tissue manipulation, based on their tactile sensation and real-time force display, thereby reducing the perceived risk of traction-related tissue injuries. Conclusions: This study represents the first clinical application of the Saroa surgical system in gynecologic surgery. The findings suggest that the system is feasible and safe for robot-assisted hysterectomy. Despite limitations such as small sample size and the absence of objective force data, the favorable surgeon-reported experience highlights the potential value of haptic feedback in improving surgical performance. These results support further investigation through larger, controlled studies and quantitative performance evaluation. Full article

Tele-ultrasound systems enable remote diagnostic imaging by transmitting both motion commands and haptic feedback between a sonographer and a robotic probe. While these systems aim to replicate conventional ultrasound procedures, they rarely address the physical strain typically experienced by sonographers. In this study, the effect of applying a force scaling strategy to haptic feedback on reducing muscular fatigue and task-induced stress during a realistic tele-ultrasound task is studied. First, a thorough operational and biomechanical analysis of the abdominal US procedure was performed to reconstruct a representative task in the laboratory. Then, a bilateral position–force tele-ultrasound architecture was implemented, and a total of 11 subjects performed the reconstructed remote ultrasound task under two randomized conditions: with and without force scaling. Surface electromyography (sEMG) signals were acquired from seven upper-limb muscles (posterior deltoid, trapezius, anterior deltoid, biceps, triceps, wrist flexors, and wrist extensors). Teleoperation-related stress was also assessed using a seven-item Likert-scale self-report questionnaire administered after each trial. Statistical significance was tested using Repeated Measures ANOVA for EMG data and the Wilcoxon signed-rank test for stress scores. The results showed a statistically significant reduction in muscle activation in 5 out of 7 muscles, and a clear mitigation of fatigue progression over time in the scaled condition. Additionally, perceived stress levels were significantly lower in the presence of force scaling in overall stress scores. These findings support the effectiveness of force scaling as a tool to enhance ergonomics in tele-ultrasound procedures without compromising the operator’s ability to perform the task. The proposed methodology proved robust and generalizable, offering valuable insight into the integration of human-centered design in tele-operated diagnostic systems. Full article

This feasibility study evaluated a wearable sensor-based haptic feedback system designed to promote ergonomic awareness and influence posture and muscle activation patterns during a standard dental procedure. Inertial measurement units (IMUs) monitored posture by tracking back and neck angles, while four surface electromyography sensors recorded muscle activation in the lower erector spinae (LES) and upper trapezius (UT) muscles. Two IMUs with vibrotactile motors delivered real-time haptic feedback when participants maintained mechanically disadvantageous postures for extended periods during a cast metal crown preparation procedure on a manikin typodont. Data from four dental students participating in a total of 24 trials, half with and half without feedback, were analyzed via a two-way ANOVA to determine the effects of feedback and activity (e.g., inspections or drilling) on posture and muscle activation. Feedback slightly increased neck angles, but back angles remained nominally unchanged. Reduced UT activation and increased right LES activation suggests altered muscle recruitment strategies. Heatmap and RULA analyses indicated a shift toward more varied and potentially safer postural distributions during feedback trials. Postural and muscle activation data were also analyzed across four activity labels, which revealed that Drilling was consistently associated with higher ergonomic risk. Real-time haptic feedback influenced posture and muscle activation in dental students, particularly by reducing UT strain despite increased neck flexion. These findings support the integration of wearable feedback systems into preclinical training to enhance ergonomic awareness and potentially reduce the risk of developing musculoskeletal disorders, to which dentists are particularly prone. Full article

Anterior segment optical coherence tomography (AS-OCT) has emerged as a crucial imaging technique in ophthalmology, particularly for evaluating intraocular structures and the behavior of phakic and secondary intraocular lenses (IOLs). This narrative review summarizes the latest findings and clinical applications of OCT regarding phakic and secondary IOLs, focusing on their effectiveness, safety, and factors influencing performance. Through a comprehensive analysis of current literature, we explore how OCT facilitates the assessment of IOLs on key anatomical parameters—such as vault, angle configuration, lens centration, tilt, and haptic positioning—essential for optimizing surgical outcomes and minimizing postoperative complications. In phakic IOLs, including posterior chamber lenses such as the Implantable Collamer Lens (ICL, STAAR Surgical, Monrovia, CA, USA) and iris-fixated lenses, such as Artiflex (Ophtec BV, Groningen, The Netherlands), OCT enables precise evaluation of the anterior segment, aiding both candidate selection and long-term monitoring. In secondary implants for aphakia—especially iris-fixated lenses like Artisan (Ophtec BV, Groningen, The Netherlands) and sutureless scleral-fixated lenses such as the Carlevale IOL (Soleko, Rome, Italy)—or those implanted via the Yamane technique, OCT provides high-resolution visualization of haptic fixation, IOL stability, and potential complications, including tilt or decentration. This review also highlights comparative insights between fixation techniques, underscores the need for standardized OCT protocols, and discusses the integration of artificial intelligence tools. In summary, the routine use of OCT in the preoperative and postoperative management of phakic and secondary IOLs has been increasingly incorporated into clinical practice, as it enhances clinical decision-making and improves patient outcomes. Full article

The field of haircutting robots is poised for a significant transformation, driven by advancements in artificial intelligence, mechatronics, and humanoid robotics. This perspective paper examines the emerging market for haircutting robots, propelled by decreasing hardware costs and a growing demand for automated grooming services. We review foundational technologies, including advanced hair modeling, real-time motion planning, and haptic feedback, and analyze their application in both teleoperated and fully autonomous systems. Key technical requirements and challenges in safety certification are discussed in detail. Furthermore, we explore how cutting-edge technologies like direct-drive systems, large language models, virtual reality, and big data collection can empower these robots to offer a human-like, personalized, and efficient experience. We propose a business model centered on supervised autonomy, which enables early commercialization and sets a path toward future scalability. This perspective paper provides a theoretical and technical framework for the future deployment and commercialization of haircutting robots, highlighting their potential to create a new sector in the automation industry. Full article

Systems presenting haptic information have emerged as an important technological advance in assisting individuals with sensory impairments or amputations, where the aim is to enhance sensory perception or provide sensory substitution through tactile feedback. These systems provide information on limb positioning, environmental interactions, and gait events, significantly improving mobility in amputees and their confidence about using such devices. This review summarizes recent progress in haptic feedback systems by providing a comparative analysis of different feedback approaches, evaluating their clinical effectiveness and usability, tactile feedback system design, and user experience, while identifying key gaps in the literature. These insights can contribute to the advancement of more effective, user-centered haptic feedback systems tailored for lower limb prosthetics. The findings are aimed at guiding future research in designing adaptive, intuitive, and clinically viable feedback mechanisms, fostering the widespread implementation of haptic systems in both assistive and rehabilitative applications. Full article