Search

The Nash equilibrium concept has previously been shown to be an important tool to understand human sensorimotor interactions, where different actors vie for minimizing their respective effort while engaging in a multi-agent motor task. However, it is not clear how such equilibria are reached. Here, we compare different reinforcement learning models to human behavior engaged in sensorimotor interactions with haptic feedback based on three classic games, including the prisoner’s dilemma, and the symmetric and asymmetric matching pennies games. We find that a discrete analysis that reduces the continuous sensorimotor interaction to binary choices as in classical matrix games does not allow to distinguish between the different learning algorithms, but that a more detailed continuous analysis with continuous formulations of the learning algorithms and the game-theoretic solutions affords different predictions. In particular, we find that Q-learning with intrinsic costs that disfavor deviations from average behavior explains the observed data best, even though all learning algorithms equally converge to admissible Nash equilibrium solutions. We therefore conclude that it is important to study different learning algorithms for understanding sensorimotor interactions, as such behavior cannot be inferred from a game-theoretic analysis alone, that simply focuses on the Nash equilibrium concept, as different learning algorithms impose preferences on the set of possible equilibrium solutions due to the inherent learning dynamics.

This letter presents a novel soft vibrotactile interface with a wide acceleration bandwidth that can be applied to a curved surface, such as a steering wheel. This haptic interface utilizes the surface charge-inducing characteristic of polyvinyl chloride (PVC) gel and adopts a design where hydraulic pressure is induced upon actuation. This working principle significantly increases the output force of the device, which enables a high-performance haptic interface. In addition, the small contact angle due to its curved shape was analyzed as an important parameter for high-frequency performance. Results showed that the proposed haptic interface can generate sufficient acceleration performance (>3 G) over a broad frequency range (90–700 Hz) with a maximum value near 6 G. Due to this high performance, user test participants could certainly feel the generated vibration with a sensation level of 22.5–44.8 dB from 10–360 Hz at 3 kV.

The use of robots has attracted researchers to design numerous haptic training methods to support motor learning. However, investigations of new methods yielded inconclusive results regarding their effectiveness to enhance learning due to the diversity of tasks, haptic designs, participants��� skill level, and study protocols. In this review, we developed a taxonomy to identify generalizable findings out of publications on haptic training. In the taxonomy, we grouped the results of studies on healthy learners based on participants��� skill level and tasks��� characteristics. Our inspection of included studies revealed that: i) Performance-enhancing haptic methods were beneficial for novices, ii) Training with haptics was as effective as training with other feedback modalities, and iii) Performance-enhancing and performance-degrading haptic methods were useful for the learning of temporal and spatial aspects, respectively. We also observed that these findings are in line with results from robotaided neurorehabilitation studies on patients. Our review suggests that haptic training can be effective to foster learning, especially when the information cannot be provided with other feedback modalities. We believe the findings from the taxonomy constitute a general guide, which can assist researchers when designing studies to investigate the effectiveness of haptics on learning different tasks.

The uncoupled stability of haptic rendering has been analyzed extensively, predominantly using passivity considerations. Yet, the role of the operator in improving the stability of haptic systems has received less attention. Here, towards a human-in-the-loop stability analysis of haptic rendering with delay, we study the effect of the operator impedance on the stability boundaries. We employ a method that tracks the $j\omega$ crossings of the roots of a characteristic second order equation of a coupled system that includes the impedance of the operator, the haptic device, the rendered virtual stiffness and damping, and the time delay. We found that the consideration of a realistic operator impedance leads to significantly less conservative stable time delay margins. Moreover, for certain arm impedance parameters, the coupled system may allow for: (1) assuring delay-independent stability, and (2) being stabilized by increasing the delay. These results indicate that a human-centered approach can push the boundaries of safe haptic feedback, especially in applications where the delays are substantial and unavoidable, such as in teleoperation.

Contemporary autonomous-driving technology relies on good environmental-perception systems and high-precision maps. For unknown environments or scenarios where perception fails, a human-in-the-loop remote-driving system can effectively complement common solutions, although safety remains an issue for its application. A haptic shared-control algorithm based on non-cooperative game theory is presented in this paper. The algorithm generates collision-free reference paths with model predictive control and predicts the driver’s path using a two-point preview model. Man-machine torque interaction is modeled as a Nash game, and the assist system’s degree of intervention is regulated in real time, according to assessments of collision risk and the driver’s concentration. Simulations of several representative scenarios demonstrate how the proposed method improves driving safety, while respecting driver decisions.

In the last two decades, the design of pseudo-haptics as a haptic presentation method that does not require a mechanical feedback device has been proposed in various research papers. Moreover, applications using pseudo-haptics have been proposed and evaluated in various contexts. However, the findings from these studies have not yet been comprehensively organized in a survey paper in the recent times. In this article, findings from a series of individual prior studies were summarized from the design through to the application proposals. First, we summarize visual stimuli designs based on the target haptic object properties to induce pseudo-haptics. Second, we summarize two special issues when designing pseudo-haptics; (1) workaround design for the visualized mismatch of visual stimuli and user input; and (2) the combination design of pseudo-haptics and physical stimuli. Third, application proposals that use pseudo-haptics for training, assistance, and entertainment are presented. This survey paper would help not only researchers in academia but also application developers who intend to use pseudo-haptics as a haptic presentation method.

Up to this day, precise manipulation still relies on human hands, which benefits from the rich neural sensing in the fingertips. For robotic hands, force perception, recognizing the softness of objects, and detecting slip can significantly improve the grasping and manipulating abilities. However, it is quite challenging to embed sensors into the compact fingertip. Here, we propose a soft sensor to perceive external forces through the output change of a pressure transducer. The soft sensor also acts as fingertip with its physical airbag. The pressure transducer inside sensor detects the contacting force. In the experiments, two fingers grasped an object at three different speeds. The feedback data were input to a random forest algorithm to perceive the softness of the contacting surface and identify the object. The accuracy was experimentally proved to be greater than 90% and have good robustness. A prototype of a robot hand employing the proposed soft fingertips was developed, which experimentally demonstrated the grasping and resistant ability to external perturbations. The robot hand manipulated a square object to track a preset trajectory using two fingers and a classical PID controller, which significantly depends on the embedded soft sensor with its force feedback, flexibility, adaptability.

Background Liver resection involves surgical removal of a portion of the liver. It is used to treat liver tumors and liver injuries. The complexity and high-risk nature of this surgery prevents novice doctors from practicing it on real patients. Virtual surgery simulation was developed to simulate surgical procedures to enable medical professionals to be trained without requiring a patient, a cadaver, or an animal. Therefore, there is a strong need for the development of a liver resection surgery simulation system. We propose a real-time simulation system that provides realistic visual and tactile feedback for hepatic parenchymal transection. Methods The tetrahedron structure and cluster-based shape matching are used for physical model construction, topology update of a three-dimensional liver model soft deformation simulation, and haptic rendering acceleration. During the liver parenchyma separation simulation, a tetrahedral mesh is used for surface triangle subdivision and surface generation of the surgical wound. The shape-matching cluster is separated via component detection on an undirected graph constructed using the tetrahedral mesh. Results In our system, cluster-based shape matching is implemented on a GPU, whereas haptic rendering and topology updates are implemented on a CPU. Experimental results show that haptic rendering can be performed at a high frequency (> 900 Hz), whereas mesh skinning and graphics rendering can be performed at 45 fps. The topology update can be executed at an interactive rate (> 10 Hz) on a single CPU thread. Conclusion We propose an interactive hepatic parenchymal transection simulation method based on a tetrahedral structure. The tetrahedral mesh simultaneously supports physical model construction, topology update, and haptic rendering acceleration.

Studies on pseudo-force feedback have reported that tactile stimuli such as skin stretch and pressure can substitute force sensation. This effect has enabled the design of a compact haptic device. However, little is known about the effect of applying pressure to the palm in terms of force substitution and augmentation, especially regarding how active and passive pressure stimuli differ. This article examines the pseudo-force effect of pressure stimuli to the palm, focusing on how it is perceived when it is applied together with a force stimulus. The method of adjustment was utilized, by which participants voluntarily moved their hands to adjust the pressure and force stimuli. The participants did this such that they felt a force equivalent to that of the reference applied to the other hand, which induced only a force stimulus. The results showed that the force sensation was significantly changed by the pressure stimulus to the palm, showing the effect of force substitution and augmentation. Furthermore, we found that there is no significant difference between the active and passive stimuli.

This letter presents a novel vibrotactile haptic system controlled by a smartphone that can be used for gait training of older adults. Compared to previous works, the system's modularity as well as its smartphone-based controller and user interface can enhance its usability and promote regular gait training of users during their daily living. Given the prevalence of reduced stride length and speed in older adults, we developed a biomechanical data-driven approach to enable improving those outcomes via modifying their underlying surrogates. A subject study was performed by recruiting 12 young participants (19–39 years) to assess the efficacy of the haptic system and our approach based on biomechanical surrogates. It was found that the participants could significantly increase their thigh and shank extensions (i.e., the surrogates) via the feedback provided by our system, and those increases resulted in higher values of their stride length and walking speed. The results provide a clear proof-of-concept for the developed biomechanics-driven haptic system for gait training of older adults to potentially improve their mobility and living independence.

Achieving efficient and human-like hopping motions with consistent consecutive patterns requires proper mechanical design and control. In this regard, we introduce a new bioinspired design and control approach comprised of a hybrid actuation system and force-based compliance control. Combining an electric motor with a pneumatic artificial muscle makes up the so-called Electric-Pneumatic Actuation (EPA) system which enables presetting the leg compliance. Using the ground reaction force for online adjustment of EPA allows controlling the leg stiffness. This approach combines a simplified version of reflex-based control and physical impedance adjustment, that resembles the human neuromuscular system in a parsimonious way. By optimizing PAM pressures and control gains for different targeted hopping heights using Bayesian optimization, we show experimentally that the proposed approach generates various stable hopping motions and yields efficient performance. Moreover, our method is shown to be capable of creating more human-like hopping patterns compared to the previous studies on the same robot.

The COVID-19 pandemic has touched upon every aspect of human experience. This article examines the shifted relationalities between research objects and fieldwork as a consequence of the pandemic. Following a psychosocial research project on the archives on queer and feminist mobilisations in Greece between 1978 and 1993, which employs ‘the haptic’ as a methodological tool, the article outlines haptic occurrences in COVID-19 times. Taking into account archival intricacies, the reflective practices of the psychosocial as well as fieldwork notes prior to and during the pandemic, the article illustrates how new ethics of touch are ascribed in current psychosocial research practices. Ultimately, the article shows how haptic archival connections – even through the restricted physical presence of sensoria – allow textual, physical and affective movements to resist and still resurface.

Objective To develop a collision engine (haptic force feedback simulator) compatible with a 5-degrees-of-freedom (DOF) haptic wand. This has broad applications such as telerobotic ultrasound systems. Integrating force feedback into systems is critical to optimize remote scanning. A collision engine compatible with a 5-DOF haptic wand was developed based on the Gilbert–Johnson–Keerthi algorithm. The collision engine calculated force during collision between the wand and a virtual object based on code developed using MATLAB. A proportional force was subsequently returned to a user via the haptic wand, thereby simulating the collision force for the user. Three experiments were conducted to assess the accuracy of the collision engine on curved and flat surfaces. Results The average errors in calculation of distances between the wand and virtual object were 2.1 cm, 3.4 cm, and 4.2 cm for the model of the human hand, cylinder, and cuboid, respectively. The collision engine accurately simulated forces on a flat surface, though was less accurate on curved surfaces. Future work will incorporate haptic force feedback into a telerobotic ultrasound system. The haptic force simulator presented here may also be used in the development of ultrasound simulators for training and education.

Affective haptic devices (AHDs) have been developed with the aim of communicating touch acts, symbolic messages, emotions, and/or providing a sense of social awareness. Within AHDs, three categories can be distinguished: mediated social touch (MST), symbolic communication systems, and awareness systems. For each of these categories, prototypes have been developed and discussed in the literature. Each such prototype, however, describes but a small part of the design space of AHDs. What is lacking is a description of the design space itself—of all choices that can be considered during the design process. Such a description will allow for a more systematic exploration of AHD designs and provides a means of combining insights gained from individual point solutions (i.e., existing prototypes). Therefore, in this article, we provide a systematic description of the design space of AHDs and its underlying dimensions based on general (e.g., revisability or synchronicity) and AHD-specific (e.g., actuation type) communication system characteristics. This resulted in 17 design dimensions, each consisting of two or more categories (the design characteristics). Based on a systematic literature search from devices up to 2019, 89 AHD prototypes were identified, and each was classified on the design dimensions. The empirical analysis of where these AHDs are located in the design space revealed, first, that potentially interesting characteristics from mediated communication, such as revisability and reviewability, are underexplored in AHDs. Second, MST devices were found to often lack those system characteristics, such as real-time modalities, that seem crucial for providing the affordances needed to simulate social touch. In particular, when comparing symbolic and awareness devices to MST devices, we found the latter to more frequently lack some of the key characteristics of face-to-face communication (i.e., bi-directional and symmetric communication). Limitations and implications are discussed.

Artificially created tactile feedback is in high demand due to fast developments in robotics, remote control in medicine, virtual reality, and smart electronics. Despite significant progress, high-quality haptic feedback devices remain challenging mainly due to the lack of stability and spatiotemporal resolution. In this work, we address these issues by the application of dynamic coatings, based on photo-responsive liquid crystal network (LCN) material. This material adapts upon an external stimulus (UV light with a power intensity of 50–90 mW/cm2) that changes its elastic properties (87% decrease of the modulus for 90 mW/cm2 power intensity of 365 nm UV light). Localized change of adaptive modulus with very high resolution (2 μm) was demonstrated.

PURPOSE: To assess the rotational stability of a new toric intraocular lens (IOL), TECNIS toric II (toric II), which is a modified version of the TECNIS toric IOL (toric I) with frosted haptics (Johnson & Johnson). METHODS: A total of 101 eyes of 101 patients who had been treated with phacoemulsification and toric IOL implantation were included. Before and 1 day, 1 week, and 1 month after surgery, uncorrected (UDVA) and corrected (CDVA) distance visual acuity were measured. Preoperative corneal astigmatism and postoperative manifest refractive astigmatism at 1 day and 1 month were analyzed. At 1 day and 1 month postoperatively, the amount of IOL axis misalignment from the intended orientation, tilt, and decentration were measured using anterior segment optical coherence tomography. RESULTS: Fifty-one eyes received the toric I IOL and 50 eyes received the toric II IOL. Toric I IOLs showed a significantly larger amount of axis misalignment than toric II IOLs at both 1 day (9.6 ± 7.6° vs 5.4 ± 4.8°, P = .003) and 1 month (9.1 ± 7.8° vs. 4.7 ± 4.2°, P = .003) postoperatively.The proportion of eyes with misalignment greater than 10° was significantly larger with toric I than toric II IOLs ( P < .001). There were no significant differences between IOLs in the amount of residual astigmatism, UDVA, CDVA, and amount of tilt and decentration at 1 day and 1 month postoperatively. CONCLUSIONS: The TECNIS toric II IOL with frosted haptics has significantly improved rotational stability compared to its previous model. [ J Refract Surg . 2022;38(10):648–653.]

PurposeThe purpose of this paper is twofold. First, it seeks to extend service and retailers understanding of how the inclusion of haptics can gamify digital service experiences. Second, it seeks to understand the moderating role of consumers orientation towards adventure in service experiences.Design/methodology/approachThis research adopts a two-study, 2 (haptic technology: present vs absent) × 2 (adventure orientation: high vs low) to test the proposed hypotheses (Study 1 n = 210, Study 2 n = 452). The data are tested using ANCOVA's and Hayes PROCESS Macro to investigate mean differences and the potential presence of two different moderated mediated relationships.FindingsThe results are consistent across the two experimental studies evidencing that the inclusion of haptics to gamify the service experience leads to significantly improved outcomes for service brands and channels. Further, the results demonstrate that the impact of haptics is greater for consumers with a lower, compared to higher, sense of adventure. Thus, the results demonstrate that whilst haptics improves consumers experiences with technological services overall, this is more prevalent for those who have “less sense of adventure”.Originality/valueThis paper sheds insight into the emerging area of haptic technology and is one of the first to specifically examine the impact of consumers “sense of adventure.”

In our practice, we often encounter the issue of centering and stabilizing scleral contact lens (SCL) in the patient's eye. This is due to the fact that the haptic part of the SCL rests on the scleral conjunctiva, which itself is toric. Рurpose. To analyze possibilities of stabilizing scleral and mini-scleral lenses in patients with different scleral toricities. Material and methods. This study was a retrospective review of 17 patient records (34 eyes); 9 patients were male and 8 female. The mean age of the patients was 38 ± 12 years. Results. The horizontal visible iris diameter amounted to 11.85 ± 0.52 mm (11.0 to 12.5 mm). All patients previously underwent fitting of SCLs for correction of ametropia. Lens diameter was chosen based on the corneal diameter, while the shape of the patient's sclera determined stabilization method. This work describes a method for determining scleral toricity. An adequate fit of spherical SCLs was not achieved in patients with toric sclera; however, the correct choice of a stabilization method made it possible to achieve congruence of the lens edge with the scleral surface in all four quadrants and obtain a high visual acuity in all patients included in the study, regardless of the lens diameter. Conclusion. Stabilization of SCLs provided a safe and comfortable wearing experience. Key words: scleral lenses, mini-scleral lenses, lens edges, scleral conjunctiva, toric periphery, limbus

Entering the 5G and internet of things (IoT) era, human–machine interfaces (HMIs) capable of providing humans with more intuitive interaction with the digitalized world have experienced a flourishing development in the past few years. Although the advanced sensing techniques based on complementary metal-oxide-semiconductor (CMOS) or microelectromechanical system (MEMS) solutions, e.g., camera, microphone, inertial measurement unit (IMU), etc., and flexible solutions, e.g., stretchable conductor, optical fiber, etc., have been widely utilized as sensing components for wearable/non-wearable HMIs development, the relatively high-power consumption of these sensors remains a concern, especially for wearable/portable scenarios. Recent progress on triboelectric nanogenerator (TENG) self-powered sensors provides a new possibility for realizing low-power/self-sustainable HMIs by directly converting biomechanical energies into valuable sensory information. Leveraging the advantages of wide material choices and diversified structural design, TENGs have been successfully developed into various forms of HMIs, including glove, glasses, touchpad, exoskeleton, electronic skin, etc., for sundry applications, e.g., collaborative operation, personal healthcare, robot perception, smart home, etc. With the evolving artificial intelligence (AI) and haptic feedback technologies, more advanced HMIs could be realized towards intelligent and immersive human–machine interactions. Hence, in this review, we systematically introduce the current TENG HMIs in the aspects of different application scenarios, i.e., wearable, robot-related and smart home, and prospective future development enabled by the AI/haptic-feedback technology. Discussion on implementing self-sustainable/zero-power/passive HMIs in this 5G/IoT era and our perspectives are also provided.

The COVID-19 pandemic has affected our nation and economy gravely, which has led to exploiting ways of setting norms for the effective distribution of healthcare advancements beyond geographical boundaries. In this paper, we propose an approach for the rapid advancement and effective distribution of healthcare in India through the enormous potential in telemedicine and haptic technology. We further address the issues in India's current healthcare infrastructure occurring due to non-availability and vacancy of doctors, social development, such as the willingness of people to invest in telemedicine by statistically analyzing bar diagrams, tabulated data, and self-assembled visual graphics. Our study shows that the potential of technology-aided approaches such as telemedicine and haptic systems in healthcare is enormous, and through effective dissemination of awareness, training, and stakeholder involvement, telemedicine and haptics could change the norms in the advancement in the healthcare system of India

The online environment has long been a sensory interaction between a brand or product and its consumers through visual imagery and sonic elements. While newer technologies have developed that cater to a customer’s more psychological need for haptics (touch), gestation, and olfaction, brands have not explored its true potential. Immersions and other forms of Human-Computer interaction have vastly developed and present scope for more than just a single sense for online consumers. While brands are employing these multisensory interfaces (vs. single-sensory) in certain product categories, it remains to be seen whether customers who unknowingly experience sensations online want to adapt to it. Several product categories could find multisensory elements beneficial. This study aims to delve deeper and understand the motivations of such behavior and identify the need for a customer to engage all its senses beyond the traditional visuals and sound while interacting with brands virtually for a more holistic experience. While external environmental factors such as pandemics have resulted in the inevitable loss of physical touchpoints, the aim is to determine whether sensory elements beyond images and sounds will benefit customer engagement.

Purpose: To compare the stability of intraocular lens (IOL) insertion methods of sutured haptics in the bag with scleral fixation to those of in the bag insertion and scleral sulcus fixation. Methods: In group of only phacodonesis, two IOL insertion methods, in the bag insertion and sutured haptics in the bag with scleral fixation were compared. In group of phacodonesis with less than 90° zonulysis, two IOL insertion methods, sutured haptics in the bag with scleral fixation and scleral sulcus fixation were compared. Postoperative 2 months and 12 months refraction were compared with target refraction and the refractive change between postoperative 2 and 12 months were compared in each group. The change of anterior chamber depth (ACD) at postoperative 2 and 12 months were compared with preoperative ACD, and the change of ACD between postoperative 2 and 12 months were compared in each group. Results: In group of only phacodonesis, the typical in the bag insertion group showed significant ACD change between postoperative 2 and 12 months (p = 0.010), but the group of sutured haptics in the bag with scleral fixation didn’t show the significant ACD change (p = 0.515). In group of phacodonesis with less than 90° zonulysis, the sulcus scleral fixation method showed significant ACD change and significant refractive change (p = 0.015, p = 0.004), but the group of sutured haptics in the bag with scleral fixation method didn’t show the significant ACD nor refractive change (p = 0.713, p = 0.106) between postoperative 2 and 12 months. Conclusions: In eyes with zonular instability, sutured haptics in the bag with scleral fixation method can promote the postoperative stability of IOL.

In vascular interventional surgery, experienced physicians rely on proximal force sensing to detect the collision and reduce vascular injury caused by surgical tools. However, in robot-assisted tele-interventional surgery (RATIS), providing high-precision force feedback to physician is still a main challenge. In this paper, a haptic robot-assisted catheter operating system with a novel spring-based haptic force interface was developed. With a closed loop force adjustment system, the haptic force interface can provide accuracy force feedback. Moreover, a collision protection function with a proximal-force-based collision detection algorithm was proposed to improve surgical safety. In case of no collision, transparency of the teleoperated system is realized; in case of collision, the provided haptic force will be amplified. The results demonstrated the usability of the developed haptic robot-assisted catheter operating system with collision protection function.

Since haptic communications have an extreme requirement for the latency performance, the overdue content delivery will decrease the application experience. In order to reduce the transmission delay, we try to construct a cache-enabled D2D-assisted content-sharing framework, where the neighboring helpers preset contents and adjust their transmission power to timely serve more requesters. In particular, we modify the existing definition of the “closest” friend and take the social relationship into account to measure the overall influence caused by available neighboring helpers. However, such cooperation consumes the storage space and energy of the helpers, and accordingly, we introduce blockchain technology to propose an effective incentive mechanism where the helpers act as consensus users of blockchain and obtain the reward, i.e., the allocated computing power by the base station (BS), by contributing their local resources. Guided by this, the benefit of each helper is defined as a tradeoff of the reward and overheads. Meanwhile, we formulate the multiuser content delivery problem with the goal of maximizing the global benefits as the multiuser content delivery game. Then, we prove that the proposed game is an exact potential game (EPG) with at least one pure-strategy Nash equilibrium (NE). Meanwhile, the context-aware content delivery-based concurrent better reply (CCDCBR) algorithm is proposed to achieve a desirable solution. Finally, simulation results verify the validity of the proposed game model as well as the proposed algorithm.

The lateral ventricle puncture is an important step of external ventricular drain. It is one of the most basic but challenging skills that must be mastered by physicians. For improving the lateral ventricle puncture skill, a novel virtual reality simulation training system equipped with haptic feedback was developed in this paper. A series of experiments and questionnaires were conducted to evaluate the fidelity of simulated haptic force and the effectiveness of this system. Both the forces generated by the haptic device during the virtual puncture and that generated during puncturing on a pig brain were obtained and compared. The results indicate that these two forces have the similar varying tendency under different puncturing conditions. In addition, two groups of neurosurgical interns named A (trained without this system) and B (trained with this system) were selected to verify the effectiveness of this system. The operation metrics, including operative dictation, operation time, positioning of Kocher’s point, times of repeated punctures, and the punctured position on lateral ventricle, were assessed by the chief physician for both groups. The results show that group B achieved higher scores than group A in all operation metrics except only operative dictation (P = 0.001). This indicates that the proposed virtual training system is an effective aid in training neurosurgery physicians’ lateral ventricle puncture skill.

Non-visual information is important for navigation in limited visibility conditions. We designed a haptic-based relocation task to examine blindfolded adults' use of geometric cues. Forty-eight participants learned to locate a corner in a parallelogram frame. They were then tested in different transformed frames: (a) a reverse-parallelogram, in which locations predicted by original length information and angle information conflicted, (b) a rectangle, which retained only length information, and (c) a rhombus, which retained only angle information. Results show that access to the environment's geometry through haptic modality is sufficient for relocation. However, adults' performances in the current task were different from that in visual tasks in previous findings. First, compared to previous findings in visual-based tasks, length information lost its priority. Approximately half of the participants relied on angle information in the conflict test and the other half relied on length. Second, though participants encoded both length and angle information in the learning phase, only one cue was relied on after the conflict test. Finally, though participants encoded the target location successfully, they failed to represent the global shape of the environment. We attribute adults' different performances in haptic-based and visual-based tasks to the high cognitive demands in encoding and using haptic spatial cues, especially length information.

What is happening when we feel touched by poetry? What are we touching when we relieve our emotions with a swear word? Are those touches mere metaphors or something else entirely? This comprehensiv...

Background Walking with a haptic tensile force applied to the hand in a virtual environment (VE) can induce adaptation effects in both chronic stroke and non-stroke individuals. These effects are reflected in spatiotemporal outcomes such as gait speed. However, the concurrent kinematic changes occurring in bilateral lower limb coordination have yet to be explored. Methods Chronic stroke participants were stratified based on overground gait speed into lower functioning (LF Results All groups showed some kinematic changes in thigh, leg and foot segments when gait speed increased during force and post-force leash as well as cane walking. These changes were also reflected in intersegmental coordination and 3D phase diagrams, which illustrated increased intersegmental trajectory areas (p Conclusions Individuals with chronic stroke who increased their gait speed when walking with tensile haptic forces and immediately after force removal, also displayed moderate concurrent changes in lower limb intersegmental coordination patterns in terms of angular displacement and velocity. Similar results were also seen with cane walking. Although symmetry was less affected, these findings appear favourable to the functional recovery of gait. Both the use of 3D phase diagrams and assigning Sobolev norm values are potentially effective for detecting and quantifying these coordination changes.

Online learning is an important aspect of higher education today. One-third of college students take at least one course online, and almost 70% of chief academic leaders say that online learning is critical to their long-term strategy [1]. Despite the success and growth of online education, the number of courses that currently offer a hands-on laboratory component is extremely limited, resulting in the lack of an entire category of engineering courses.

BACKGROUND: When a person walks a dog, information from variables of their own postural control is integrated with haptic information from the dog’s movements (e.g., direction, speed of movement, pulling forces). AIM: We examined how haptic information provided through contact with a moving endpoint (here, the leash of a dog walking on a treadmill) influenced an individual’s postural control during a quiet tandem standing task with and without restricted vision and under various elevations of the support surface (increased task difficulty levels). METHOD: Adults performed a 30-second quiet tandem stance task on a force platform while holding a leash attached to a dog who walked on a treadmill parallel to the force platform. Conditions included: haptic contact (dog and no-dog), vision constraint (eyes open, EO, and eyes closed, EC), and surfaces (4 heights). RESULTS: Interaction between haptic condition and vision showed that contact with the dog leash reduced root mean square (RMS) and mean sway speed (MSS). RMS showed that the highest surface had the greatest rate of sway reduction during haptic contact with EC, and an increase with EO. CONCLUSION: The dog’s movements were used as a haptic reference to aid balance when eyes were closed. In this condition, contact with the dog’s leash reduced the extent of sway variability on the higher surfaces.

The asymmetry in bilateral teleoperation, i.e., the differences of mechanical structures, sizes, and number of joints between the master and slave robots, can introduce kinematicsr edundancy and workspace inequality problems. In this article, a novel shared autonomy control strategy is proposed for handling the asymmetry of bilateral teleoperation, which has two main contributions. First, to deal with kinematics redundancy, the proposed strategy provides a self-regulation algorithm of orientation that allows the operator to solely use the master position command to simultaneously control the slave’s position and orientation. Second, to deal with workspace inequality, the proposed strategy enables the slave’s workspace to be dynamically tunable to adapt to various task spaces without influencing the smoothness of the robot’s movement. The experiments on a platform consisting of a six-degree of freedom (DoF) UR10 robot and a 3-DoF haptic device are given to validate the effectiveness of the proposed control strategy., Funding agency:AI.MEE Program: AutoDIVE

Cross-modal communication is playing an increasingly important role in improving receivers’ immersive experience. The main challenge lies in ensuring the heterogeneous requirements of the cross-modal stream. Especially, the discontinuity of the received haptic signals caused by the delay should be eliminated. Unfortunately, existing schemes study the cross-modal stream separately, which leads to that the haptic signal is distorted, or the audio-visual quality is reduced. To solve this problem fundamentally, we propose a joint transmission framework combining prediction and device-to-device (D2D) communication by taking advantage of the correlation of the haptic signals and the proximity feature of the receivers. Specifically, on the theoretical end, to completely eliminate the discontinuity, we propose a prediction mechanism by predicting and sending the future signals in advance. To compensate for the reliability loss brought by prediction, D2D links are efficiently established on the receivers’ side. On the technical end, we first design a minimum resource (e.g., power) consumption search algorithm based on the binary search to obtain the optimal prediction horizon. Moreover, we develop a simple but efficient transmission mode selection algorithm based on the Hungarian algorithm. Experimental results demonstrate the advantages of our proposed scheme in saving the power consumption.

Purpose Digital media has brought a revolution, making the world a global village. For people who are visually impaired and people with visual and hearing impairment, navigating through the digital world can be as precarious as moving through the real world. To enable them to connect with the digital world, we propose a solution, Haptic Encoded Language Framework (HELF), that uses haptic technology to enable them to write digital text using swiping gestures and understand the text through vibrations. Method We developed an Android application to present the concept of HELF and evaluate its performance. We tested the application on 13 users (five visually impaired and eight sighted individuals). Results The preliminary exploratory analysis of the proposed framework using the Android application developed reveals encouraging results. Overall, the reading accuracy has been found to be approximately 91%, and the average CPM is found to be 25.7. Conclusion The volunteering users of the HELF Android application found it useful as a means of using the digital media and recommended its usage as an assistive technology for the visually challenged. The results of their performance of using the application motivate further research and development in the proposed work to make HELF more usable by people who are visually impaired and people with visual and hearing impairment.

Legged robot navigation in extreme environments can hinder the use of cameras and laser scanners due to darkness, air obfuscation or sensor damage. In these conditions, proprioceptive sensing will continue to work reliably. In this paper, we propose a purely proprioceptive localization algorithm which fuses information from both geometry and terrain class, to localize a legged robot within a prior map. First, a terrain classifier computes the probability that a foot has stepped on a particular terrain class from sensed foot forces. Then, a Monte Carlo-based estimator fuses this terrain class probability with the geometric information of the foot contact points. Results are demonstrated showing this approach operating online and onboard a ANYmal B300 quadruped robot traversing a series of terrain courses with different geometries and terrain types over more than 1.2km. The method keeps the localization error below 20cm using only the information coming from the feet, IMU, and joints of the quadruped., Autonomous Robots. arXiv admin note: substantial text overlap with arXiv:2005.01567

The booming wearable market and recent advances in material science has led to the rapid development of the various wearable sensors, actuators, and devices that can be worn, embedded in fabric, accessorized, or tattooed directly onto the skin. Wearable actuators, a subcategory of wearable technology, have attracted enormous interest from researchers in various disciplines and many wearable actuators and devices have been developed in the past few decades to assist and improve people’s everyday lives. In this paper, we review the actuation mechanisms, structures, applications, and limitations of recently developed wearable actuators including pneumatic and hydraulic actuators, shape memory alloys and polymers, thermal and hygroscopic materials, dielectric elastomers, ionic and conducting polymers, piezoelectric actuators, electromagnetic actuators, liquid crystal elastomers, etc. Examples of recent applications such as wearable soft robots, haptic devices, and personal thermal regulation textiles are highlighted. Finally, we point out the current bottleneck and suggest the prospective future research directions for wearable actuators.

In this paper, a study on wearable exoskeleton devices which are capable of delivering sensation to the fingers while interacting with the virtual objects in virtual reality environment has been conducted. A force-controllable hand exoskeleton system is proposed, which is able to apply force feedback to the fingertip while allowing natural finger motions. The linkage structure was inspired by the skeletal structure of a human finger. Moreover, a series elastic actuator (SEA) mechanism, which consisted of a linear motor, a spring and a potentiometer, was presented as an actuating system. The force transmission through linkage has been investigated to ensure the force feedback ability at the fingertip. By using a PID controller, the proposed actuator module could generate the desired force in two different modes: free mode and interaction mode. The experimental results show that the proposed system could effectively deliver forces to the fingertips.

There is a steadily growing number of mobile communication systems that provide spatially encoded tactile information to the humans’ torso. However, the increased use of such hands-off displays is currently not matched with or supported by systematic perceptual characterization of tactile spatial discrimination on the torso. Furthermore, there are currently no data testing spatial discrimination for dynamic force stimuli applied to the torso. In the present study, we measured tactile point localization (LOC) and tactile direction discrimination (DIR) on the thoracic spine using two unisex torso-worn tactile vests realized with arrays of 3 × 3 vibrotactile or force feedback actuators. We aimed to, first, evaluate and compare the spatial discrimination of vibrotactile and force stimulations on the thoracic spine and, second, to investigate the relationship between the LOC and DIR results across stimulations. Thirty-four healthy participants performed both tasks with both vests. Tactile accuracies for vibrotactile and force stimulations were 60.7% and 54.6% for the LOC task; 71.0% and 67.7% for the DIR task, respectively. Performance correlated positively with both stimulations, although accuracies were higher for the vibrotactile than for the force stimulation across tasks, arguably due to specific properties of vibrotactile stimulations. We observed comparable directional anisotropies in the LOC results for both stimulations; however, anisotropies in the DIR task were only observed with vibrotactile stimulations. We discuss our findings with respect to tactile perception research as well as their implications for the design of high-resolution torso-mounted tactile displays for spatial cueing. Supplementary Information The online version contains supplementary material available at 10.1007/s00221-021-06181-x.

Evidence suggests that dissatisfaction with body image in women can be enhanced by exposure to media’s idealized images. The theory of social comparison and the avoidance hypothesis offer contradictory explanations of this relationship. We compare these two theories using a haptic virtual reality environment. We ask 42 female participants to interact with one of four types of virtual humans (VH) randomly assigned to them. The interaction task involves giving a virtual hug to a normal weight or overweight male or female VH. We verify the hypothesis that participants’ satisfaction with particular body parts and their anti-fat attitudes will determine the choice of the body area of the VH they will virtually touch. Our results show that: (1) touching VH lower torso is predicted by less anti-fat attitude, and avoidance of the upper torso and upper limb areas, and (2) touching VH shoulder and upper limbs areas is predicted by concerns with own stomach area and avoidance of VH lower torso and stomach waist areas. Our results tend to support the avoidance hypothesis as well as other research findings on anti-fat attitudes.

Impulse force is effective for purposes such as system analysis, mobile robots, and haptic devices. However, the most popular DC motor actuator is not suitable for generating an impulse force. Thus...

As techniques for modern cataract surgery have expanded and premium intraocular lens (IOL) use is now widespread, patient expectations are high. The need for IOL explantation, whilst still low, remains an ongoing issue. Intraocular lens explantation can be challenging for a number of reasons and as such we have introduced an additional technique to add to the surgeon’s repertoire. Bimanual haptic stripping of fibrosis at the specific area where the haptic is adherent to the capsular bag is an effective strategy to aid in dissection of haptics without compromising the capsule or zonules. Given the challenges associated with IOL explantation, newly designed IOLs need to avoid these “sticking points” at which the IOLs interact with the fibrosed capsule. Techniques we have evolved and which are described below should assist anterior segment surgeons to facilitate IOL removal in an efficient and safe way.

BACKGROUND: Video games can be used to motivate repetitive movements in paediatric rehabilitation. Most upper limb videogaming therapies do not however include haptic feedback which can limit their impact. OBJECTIVE: To explore the effectiveness of interactive computer play with haptic feedback for improving arm function in children with cerebral palsy (CP). METHODS: Eleven children with hemiplegic CP attended 12 therapist-guided sessions in which they used a gaming station composed of the Novint Falcon, custom-built handles, physical supports for the child’s arm, games, and an application to manage and calibrate therapeutic settings. Outcome measures included Quality of Upper Extremity Skills Test (QUEST) and Canadian Occupational Performance Measure (COPM). The study protocol is registered on clinicaltrials.gov (NCT04298411). RESULTS: Participants completed a mean of 3858 wrist extensions and 6665 elbow/shoulder movements during the therapist-guided sessions. Clinically important improvements were observed on the dissociated and grasp dimensions on the QUEST and the performance and satisfaction scales of the COPM (all p< 0.05). CONCLUSION: This study suggests that computer play with haptic feedback could be a useful and playful option to help improve the hand/arm capacities of children with CP and warrants further study. The opportunities and challenges of using low-cost, mainstream gaming software and hardware for therapeutic applications are discussed.

When lifting or moving a novel object, humans are routinely able to quickly characterize the nature of the unknown load and swiftly achieve the desired movement trajectory. It appears that both tactile and proprioceptive feedback systems help humans develop an accurate prediction of load properties and determine how associated limb segments behave during voluntary movements. While various types of limb movement information, such as position, velocity, acceleration, and manipulating forces, can be detected using human tactile and proprioceptive systems, we know little about how the central nervous system decodes these various types of movement data, and in which order or priority they are used when developing predictions of joint motion during novel object manipulation. In this study, we tested whether the ability to predict motion is different between position- (elastic), velocity- (viscous), and acceleration-dependent (inertial) loads imposed using a multiaxial haptic robot. Using this protocol, we can learn if the prediction of the motion model is optimized for one or more of these types of mechanical load. We examined ten neurologically intact subjects. Our key findings indicated that inertial and viscous loads showed the fastest adaptation speed, whereas elastic loads showed the slowest adaptation speed. Different speeds of adaptation were observed across different magnitudes of the load, suggesting that human capabilities for predicting joint motion and manipulating loads may vary systematically with different load types and load magnitudes. Our results imply that human capabilities for load manipulation seems to be most sensitive to and potentially optimized for inertial loads.

Objective: This work presents the development and validation of an interactive simulation training platform for the minimally invasive repair of pectus excavatum, otherwise known as the Nuss procedure. Methods: The challenges and implications of developing both an all-virtual and an all-physical version of the simulator are investigated in a training context. A hybrid system is then developed that integrates virtual and physical constituents and a haptic interface to reproduce the primary steps of the procedure and to satisfy clinically relevant prerequisites for its training system. Furthermore, this work carries out a study to investigate the system's face, content, and construct validity. Results: Objective and subjective evaluations of the system demonstrate its utility for surgical training and establish various levels of its validity. Conclusion: A hybrid virtual/physical configuration of the trainer can efficiently and realistically reproduce the primary steps of the procedure. Significance: Outside of this work, a simulation and training platform for the Nuss procedure is not available. This system was developed in close collaboration with the pioneers of this surgical technique.

Background Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia that can cause severe heart problems. Catheter ablation is one of the most ideal procedures for the treatment of AF. Physicians qualified to perform this procedure need to be highly skilled in manipulating the relevant surgical devices. This study proposes an interactive surgical simulator with high fidelity to facilitate efficient training and low-cost medical education. Methods We used a shared centerline model to simulate the interaction between multiple surgical devices. An improved adaptive deviation-feedback approach is proposed to accelerate the convergence of each iteration. The periodical beating of the human heart was also simulated in real time using the position-based dynamics (PBD) framework to achieve higher fidelity. We then present a novel method for handling the interaction between the devices and the beating heart mesh model. Experiments were conducted in a homemade simulator prototype to evaluate the robustness, performance, and flexibility of the proposed method. Preliminary evaluation of the simulator was performed by medical students, residents, and surgeons. Results The interaction between surgical devices, static vascular meshes, and beating heart mesh was stably simulated in a frame rate suitable for interaction. Conclusion Our simulator is capable of simulating the procedure of catheter ablation with high fidelity and provides immersive visual experiences and haptic feedback.

This article describes three collaborative projects designed to explore tactile and haptic encounters with visual art. As a blind person, the author takes advantage of touch tours offered in many of the world’s museums. As rewarding as these can be, she often leaves feeling that there is something missing. She is aware that people who witness a touch tour for blind people, both companions who might be with them and strangers who might observe it, are curious, even envious. It seems only right that she, and other blind people who enjoy this privilege, have a responsibility to share the experience as a way to expand cultural knowledge about art. The projects described here enable her to begin to establish a taxonomy and vocabulary of tactile and haptic aesthetics, and model tactile descriptions of art that can benefit anyone. She does this both to reciprocate for the privilege cultural institutions bestowed on her, as well as to show that touch is not merely a poor substitute for sight, but rather a different mode of inquiry and appreciation. She hopes this work will support challenges to the ocularcentrism of the museum sector by showing how art can engage the full human sensorium. These projects all took place in the years leading up to the Covid-19 global pandemic and were a small part of initiatives at arts institutions to promote equity and inclusion by drawing on the knowledge and expertise of members of marginalized communities. As these institutions reopen post-pandemic and restructure their staff and programming, it remains to be known if they will continue the progress toward greater inclusion or return to previous models designed to serve only normative audiences. In her conclusion, the author speculates on the kind of systematic changes that will need to happen to continue to diversify museum audiences and increase multisensory access to art.

We present a hydrostatic teleoperator that provides physicians remote access inside the MRI bore and enables real-time MRI guided interventions such as liver biopsies. The device consists of a custom six-axis arm and a needle insertion end effector. The manipulator is passive and backdrivable with a near one-to-one mapping of motions and forces between the input and output. The six-axis arm translates and orients the needle during insertion and passively reflects respiratory motion while maintaining contact with the skin surface. Arm joints employ novel rotary rolling-diaphragms that provide stiff and low-friction rotational motion without the need for cables, belts, or gear mechanisms found in other solutions. We perform experiments to characterize the device’s force and position tracking and demonstrate its functionality with path following tasks. Our results find a system roll-off frequency at 20Hz and that teleoperation tasks are performed comparably to holding the output directly. We motivate the need for force transparency in MRI guided biopsies with a user study in which five radiologists perform phantom membrane puncture biopsies using the needle insertion mechanism. The results indicate a 50% reduction in scans and a 14.5% decrease in membrane overshoot when force feedback is present.

Tele-impedance augments classic teleoperation by enabling the human operator to actively command remote robot stiffness in real-time, which is an essential ability to successfully interact with the unstructured and unpredictable environment. However, the literature is missing a study on benefits and drawbacks of different types of stiffness command interfaces used in bilateral tele-impedance. In this article, we introduce a term called coupling effect, which pertains to the coupling between human-commanded stiffness going to the remote robot and force feedback coming from the remote robot. We hypothesize that, whenever the operator's commanded stiffness and force feedback are subject to coupling effect (e.g., muscle activity based stiffness command interfaces), force feedback can invoke involuntary changes in the commanded stiffness due to human reflexes. Although the coupling effect takes away some degree of the operator's control over the commanded stiffness, these involuntary changes can be either beneficial (e.g., during position tracking) or detrimental (e.g., during force tracking) to the task performance on the remote robot side. We examined the coupling effect in an experimental study with $\mathbf {16}$ participants, who performed position and force tracking tasks by using both coupled type (muscle activity based) and decoupled type (external device based) of interface. The results demonstrate a benefit of the coupling effect when the remote robot is operating in presence of unexpected force perturbations, where lower absolute error in position tracking task was observed. On the other hand, the decoupled type of interface is beneficial for force tracking tasks on the remote robot side, such as establishing or maintaining a stable contact with objects. However, the coupling effect negatively influences the commanding of reference stiffness to the remote robot in both position and force tracking tasks for the coupled type of interface, compared to the decoupled type of interface, which is not affected.