Impact of Sensory Haptic Vibrotactile Feedback on Manual Dexterity in Augmented Reality.

Force feedback drives sim racing performance: The influence of force and vibrotactile haptic feedback in simulator steering wheels

The poster describes a multisensory simulation of plucking guitar strings in virtual reality and a user study evaluating the simulation. Auditory feedback is generated by a physics-based simulation of guitar strings, and haptic feedback is provided by a combination of high fidelity vibrotactile actuators and a Phantom Omni. The study compared four conditions: no haptic feedback, vibrotactile feedback, force feedback, and a combination of force and vibrotactile feedback. The results indicate that the combination of vibrotactile and force feedback elicits the most realistic experience, and during this condition, participants were less likely to inadvertently hit strings. Notably, no significant differences were found between the conditions involving either vibrotactile or force feedback.

Most prosthetic hand users are limited to visual feedback of movement performance. To characterize the benefit of vibrotactile feedback for a task that lacks haptic feedback, a virtual environment was used to experimentally manipulate visual, task-relevant haptic, and remote vibrotactile feedback on simple object manipulation for unimpaired subjects. The combination of visual and remote vibrotactile feedback was compared to visual feedback alone, and to simultaneous visual and direct haptic feedback to represent ideal performance. Visual and vibrotactile feedback resulted in improvement of most performance variables including difficulty ratings relative to visual feedback alone. However addition of sensory cues to visual feedback increased trial times and the increase was steeper for vibrotactile than for haptic feedback. Specifically, during vibrotactile feedback the velocity did not change, but the duration of execution increased due to improved performance, resulting in increased trial times. This result suggests future exploration of performance improvement and execution speed for augmented sensory feedback.

Vibrotactile haptic feedback is a non-invasive method of providing tactile sensory feedback to amputees that has been shown to improve prosthetic task performance. However, current haptic feedback technologies remain inaccessible to much of the amputee population due to unscalable, tethered, and non-retrofittable designs that are difficult to distribute. In this work, we propose a wireless, retrofittable, scalable, and distributable haptic feedback system, ‘Haptic Touch’ using flexible PCBs. The proposed system consists of a tactile sensing glove with 27 tactile sensors and a haptic feedback armband with 6 vibration motors: both featuring rechargeable batteries, wireless communication, and embedded processing. As simple demonstrations of potential experiments that can be investigated using Haptic Touch, we conducted two preliminary experiments: 1) evaluating two-point touch vibrotactile discrimination accuracy and 2) evaluating the effect of different haptic feedback strategies on object manipulation. Our results showed that participants were able to discriminate two-point touch stimuli via vibrotactile feedback with 83% accuracy. Furthermore, our object manipulation experiment showed that haptic feedback based on the derivative of force led to a trend of improved performance compared to proportional feedback. Future studies can leverage the Haptic Touch platform developed here as a distributable research tool to further study and optimize vibrotactile sensory feedback for amputees.

BackgroundDespite the technological advancements in myoelectric prostheses, body-powered prostheses remain a popular choice for amputees, in part due to the natural sensory advantage they provide. Research on haptic feedback in myoelectric prostheses has delivered mixed results. Furthermore, there is limited research comparing various haptic feedback modalities in myoelectric prostheses. In this paper, we present a comparison of the feedback intrinsically present in body-powered prostheses (joint-torque feedback) to a commonly proposed feedback modality for myoelectric prostheses (vibrotactile feedback). In so doing, we seek to understand whether the advantages of kinesthetic feedback present in body-powered prostheses translate to myoelectric prostheses, and whether there are differences between kinesthetic and cutaneous feedback in prosthetic applications.MethodsWe developed an experimental testbed that features a cable-driven, voluntary-closing 1-DoF prosthesis, a capstan-driven elbow exoskeleton, and a vibrotactile actuation unit. The system can present grip force to users as either a flexion moment about the elbow or vibration on the wrist. To provide an equal comparison of joint-torque and vibrotactile feedback, a stimulus intensity matching scheme was utilized. Non-amputee participants (n=12) were asked to discriminate objects of varying stiffness with the prosthesis in three conditions: no haptic feedback, vibrotactile feedback, and joint-torque feedback.ResultsResults indicate that haptic feedback increased discrimination accuracy over no haptic feedback, but the difference between joint-torque feedback and vibrotactile feedback was not significant. In addition, our results highlight nuanced differences in performance depending on the objects’ stiffness, and suggest that participants likely pay less attention to incidental cues with the addition of haptic feedback.ConclusionEven when haptic feedback is not modality matched to the task, such as in the case of vibrotactile feedback, performance with a myoelectric prosthesis can improve significantly. This implies it is possible to achieve the same benefits with vibrotactile feedback, which is cheaper and easier to implement than other forms of feedback.

In this paper, we explore the use of vibrotactile haptic feedback to improve performance of a sensory-motor task. Our specific application is seated posture guidance. Poor sitting postures, over time, can lead to health concerns such as low back pain. We propose a real-time haptic feedback system that actively senses and guides a person to a desired posture. We have instrumented an ergonomic office chair with a simple system using 7 force-sensitive resistors (FSRs) for posture detection and 6 vibrotactile actuators (“tactors”) for haptic feedback. When the chair detects that the subject is not sitting in the desired posture, one or more tactors will vibrate, directing the subject towards or away from a certain position. In a pilot study of 10 subjects (age 23.9±1.45, weight 71.1±13.6kg, height 175±11.2cm), 100% sat in the reference posture (upright) more often when there was haptic feedback than when there was not. Additionally, when haptic feedback was temporarily disabled without the subject's knowledge, all of the subjects continued to sit in upright or near-upright postures. These findings suggest that vibrotactile feedback can be an effective means of communicating musculoskeletal commands to the human sensory-motor system, especially for motor training and rehabilitation.

Haptic feedback may support immersion and presence in virtual reality (VR) environments. The emerging market of consumer devices offers first devices which are expected to increase the degree of feeling being actually present in a virtual environment. In this paper we introduce a novel evaluation that examines the influence of different types of haptic feedback on presence and performance regarding manual tasks in VR. Therefore, we conducted a comprehensive user study involving 14 subjects, who performed throwing, stacking and object identification tasks in VR with visual (i.e., sensory substitution), vibrotactile or force feedback. We measured the degree of presence and task-related performance metrics. Our results indicate that regarding presence vibrotactile feedback outperforms haptic feedback which performs better than visual feedback only. In addition, force feedback significantly lowered the execution time for the throwing and the stacking task. In object identification tasks, the vibrotactile feedback increased the detection rates compared to the vibrotactile and force feedback, but also increased the required time of identification. Despite the inadequacies of the still young consumer technology, there were nevertheless strong indications of connections between presence, task fulfillment and the type of haptic feedback.

Distribution and relation of two arm function tests, Box and Blocks test and Nine Hole Peg test, across disease severity levels and types of multiple sclerosis

Dual Users. Another way to make use of haptic devices for enhancing hands-on training is illustrated in Zhang et al. In this study, the haptic devices are not used to interact with the objects in a virtual world as in González-Mena and Neri et al., but to reproduce the expert gestures on the hands of the trainees. More precisely, the surgical tools handled by the expert are connected to individual haptic devices, each one recording in real time its connected tool trajectory. These trajectories are sent to the trainees' devices, which, in turn, guide the tools of the trainees. Thus, trainees can follow in their hands the expert tool trajectories, instead of only watching them and reproducing them on their own as usual. This experimental study suggests that haptic feedback superimposed on the trainee's motions can facilitate the performance of novice operators experiencing moments of difficulty, which was something that was already observed in other works (see the discussion of Zhang et al. for references). Even if the small sample size and use of a simple task limit the generalizability of their findings, this study illustrates that haptic training can be realized without any 3D virtual world, which requires accurate modeling for realistic haptic rendering of a complex task. Tactile Feedback. In Ratschat et al., the authors designed a shape exploration experiment to evaluate the effectiveness of multimodal tactile and kinesthetic feedback on shape perception. Sixteen participants were involved to reproduce different two-dimensional shapes with diverse characteristics in free space after exploring the shapes with two haptic feedback conditions: 1) kinesthetic feedback only and 2) kinesthetic plus tactile feedback. The kinesthetic feedback mechanism was implemented through an adapted single-degree-of-freedom SenseGlove Nova mechanism with an integrated electromagnetic brake. And tactile feedback was provided with a cable-driven platform mounted on the fingertip. To measure the participants' ability to perceive and reproduce the rendered shapes, the authors recorded the time participants spent exploring and reproducing the shapes and the error between the rendered and reproduced shapes after exploration and assessed the workload and motivation with questionnaires. Experimental results show that in a virtual shape exploration task without visual feedback, providing tactile and kinesthetic feedback is associated with more accurate and careful shape reproduction compared to exploring shapes with only kinesthetic feedback. Besides, the addition of tactile feedback does not seem to reduce the time spent during exploration, nor does it have an effect on motivation or workload. Thus, combining haptic and kinesthetic feedback could create more realistic virtual environments that may lead to better training results and easier transfer to real-world tasks, having implications across a variety of applications and training scenarios.Vibrotactile. Similarly, in Boutin et al . , the authors combined haptic (vibrotactile) feedback through the use of a haptic glove with a VR simulator for mixed-reality surgical training. They specifically focused on the potential for enhanced sensory feedback within VR. The authors chose to investigate External Ventricular Drain Placement (EVD), a common neurosurgery procedure, as a starting point. Experimental results demonstrated the simulator's accuracy, even though one major limitation was a lack of kinesthetic feedback. Like Ratschat et al., this work shows the potential to create more realistic mixed-reality environments that could extend beyond surgical applications.Kinesthetic. Force feedback plays a vital role in developing surgical skills, yet many virtual reality simulators lack this feature, creating a significant disparity between physical trainers and their digital counterparts, potentially limiting their effectiveness. In Abinaya and Manivannan, the authors take a different approach and use haptic feedback as an assessment metric for surgical training, focussing on laparoscopic surgery using a virtual reality simulator. By incorporating haptic feedback, they replicate the forces between the tool and the tissue, which directly correlate to tissue trauma. A virtual laparoscopic force model is incorporated into the simulator and used to determine the just noticeable differences of the laparoscopic grasping force. The results suggest that a simple linear model is sufficient for gripper force feedback, and a non-linear model does not affect the force perception. Expert laparoscopic surgeons agree that haptic feedback improves learning performance, and the force model improves the accuracy of object interaction during the gripping task.Innovative approaches to enhance surgical training must foster motor and sensory skills while reducing cognitive burden, lowering costs, and being conducive to faster design processes. This collection, the third on the topic of Haptic Training Simulation, underscores the potential of hapticenabled virtual reality tools in shaping the future of surgical education and improving patient outcomes.

This study focuses on virtual rehabilitation (VR) and augmented reality (AR). In previous study, the effect of improving the function of rehabilitation by VR has been shown. It is useful for stroke survivors as what can be done at home. This study examin usefulness of box and block test (BBT) with VR and AR. Out final goal of this study is to make it possible to do rehabilitation at the home with virtual rehabilitation test, and we create an environment where each person can maintain and improve their own performance at own home, so that rehabilitation can be continued in daily life.

BackgroundMeasuring arm and hand function of the affected side is vital in stroke rehabilitation. Therefore, the Virtual Peg Insertion Test (VPIT), an assessment combining virtual reality and haptic feedback during a goal-oriented task derived from the Nine Hole Peg Test (NHPT), was developed. This study aimed to evaluate (1) the concurrent validity of key outcome measures of the VPIT, namely the execution time and the number of dropped pegs, with the NHPT and Box and Block Test (BBT), and (2) the test-retest-reliability of these parameters together with the VPIT’s additional kinetic and kinematic parameters in patients with chronic stroke.The three tests were administered on 31 chronic patients with stroke in one session (concurrent validity), and the VPIT was retested in a second session 3–7 days later (test-retest reliability). Spearman rank correlation coefficients (ρ) were calculated for assessing concurrent validity, and intraclass correlation coefficients (ICCs) were used to determine relative reliability. Bland-Altman plots were drawn and the smallest detectable difference (SDD) was calculated to examine absolute reliability.ResultsFor the 31 included patients, 11 were able to perform the VPIT solely via use of their affected arm, whereas 20 patients also had to utilize support from their unaffected arm. For n = 31, the VPIT showed low correlations with the NHPT (ρ = 0.31 for time (Tex[s]); ρ = 0.21 for number of dropped pegs (Ndp)) and BBT (ρ = −0.23 for number of transported cubes (Ntc); ρ = −0.12 for number of dropped cubes (Ndc)). The test-retest reliability for the parameters Tex[s], mean grasping force (Fggo[N]), number of zero-crossings (Nzc[1/sgo/return) and mean collision force (Fcmean[N]) were good to high, with ICCs ranging from 0.83 to 0.94. Fair reliability could be found for Fgreturn (ICC = 0.75) and trajectory error (Etrajgo[cm]) (0.70). Poor reliability was measured for Etrajreturn[cm] (0.67) and Ndp (0.58). The SDDs were: Tex = 70.2 s, Ndp = 0.4 pegs; Fggo/return = 3.5/1.2 Newton; Nzc[1/s]go/return = 0.2/1.8 zero-crossings; Etrajgo/return = 0.5/0.8 cm; Fcmean = 0.7 Newton.ConclusionsThe VPIT is a promising upper limb function assessment for patients with stroke requiring other components of upper limb motor performance than the NHPT and BBT. The high intra-subject variation indicated that it is a demanding test for this stroke sample, which necessitates a thorough introduction to this assessment. Once familiar, the VPIT provides more objective and comprehensive measurements of upper limb function than conventional, non-computerized hand assessments.

Proprioception is central for motor control and its role must also be taken into account when designing motor rehabilitation training protocols. This is particularly important when dealing with motor deficits due to proprioceptive impairment such as peripheral sensory neuropathy. In these cases substituting or augmenting diminished proprioceptive sensory information might be beneficial for improving motor function. However it still remains to be understood how proprioceptive senses can be improved by training, how this would translate into motor improvement and whether additional sensory modalities during motor training contribute to the sensorimotor training process. This preliminary study investigated how proprioceptive/haptic training can be augmented by providing additional sensory information in the form of vibro-tactile feedback. We tested the acuity of the wrist proprioceptive position sense before and after robotic training in two groups of healthy subjects, one trained only with haptic feedback and one with haptic and vibro-tactile feedback. We found that only the group receiving the multimodal feedback significantly improved proprioceptive acuity. This study demonstrates that non-proprioceptive position feedback derived from another somatosensory modality is easily interpretable for humans and can contribute to an increased precision of joint position. The clinical implications of this finding will be outlined.

Background:Norms for children aged 6–19 years were developed in 1985 for the BBT and updated in 2013 for 3–10-year-olds. Evidence suggests that past normative data may need to be updated due to changes in children’s hand use over the past 40 years.Purpose:To compare children’s performance on the BBT with existing 1985 normative data.Study Design:Secondary analysis of a cross-sectional observational study to validate the Complete Minnesota Dexterity Test (CMDT) using the Box and Block Test (BBT).Methods:All were healthy volunteers, aged 7 to 18 years, with no known physical, cognitive, or emotional conditions. Participants completed study procedures in a pediatric hospital. During data collection we noted low performance on the BBT and hypothesized a decline compared to the 1985 norms. Participants completed one trial of the BBT with each hand. We compared our sample to the normative sample using mean number of blocks placed in 60 seconds and standard error of the means using two-tailed, one sample t-tests.Results:Of 816 children screened, 181 were eligible and consented to participate. A total of 98 females and 83 males participated. Each gender-by-age group-by-hand category ranged from 4–21 participants. In each group, means were statistically significantly lower than norms, indicated by nonoverlapping 95% confidence intervals and t-test results. The difference in blocks placed in 60 seconds ranged from 9.1 to 21.1 fewer blocks.Discussion:This study suggests that children’s manual dexterity has declined over the past 40 years. Clinicians should consider this when using the BBT to evaluate performance. This study lacked enough subjects to establish new normative data but suggests the 1985 norms need to be updated.Conclusions:Our findings provide evidence of a decline in manual dexterity among children on the Box and Block Test (BBT) since 1985.

Virtual reality (VR) offers immersive visual and auditory experiences, transporting users to alternate realities. However, existing VR systems lack realistic haptic feedback mechanisms, resulting in unsatisfactory immersive experiences. In this study, we developed and tested a haptic glove that simulates realistic tactile sensations, enhancing user interaction with virtual artifacts. Our research investigates the impact of finger-specific vibrotactile feedback (FSVF) on user experience in virtual museum environments. Using a mixed-methods approach, 30 participants engaged in object-manipulation tasks in three settings: no haptic feedback, standard controller feedback, and vibrotactile glove feedback. The findings demonstrate that the vibrotactile glove approach considerably improves user accuracy, efficiency, immersion, and satisfaction compared with other traditional interaction methods. Participants completed tasks more accurately and quickly with the glove, reporting high levels of engagement and immersion. The results highlight the potential of advanced haptic feedback in transforming virtual reality technology, particularly for educational and cultural applications. Further, they provide valuable insights for designing and applying future haptic technology in immersive environments.

Virtual Reality (VR) in surgical simulation is an evolving field with the potential to overcome traditional limitations in surgical education.Depending on the curricular need, the addition of haptic feedback can improve the environment's realism.This work presents a novel haptics-enabled VR simulator designed to enhance the placement of an external ventricular drain (EVD) during neurosurgical training through the integration of haptic technology.The simulator, developed using open-source software such as Blender, GIMP, and Unreal Engine, offers high-fidelity 3D models and realistic material interactions.By leveraging the SenseGlove NOVA haptic gloves, the simulator provides force feedback and vibrotactile sensations, enhancing realism.Results demonstrated accurate simulation of the surgical procedure, with oscillating force feedback providing realistic burr hole creation, and haptic feedback providing necessary sensations throughout catheter insertion.Due to current limitations in providing solely vibrotactile feedback, future research involves seamlessly integrating kinesthetic feedback along with the vibrotactile feedback, to further enhance accuracy and realism.Although future improvements are required, this device shows that the integration of haptic feedback not only enhances the realism of surgical simulation, but also provides structured quantitative feedback, providing the potential to improve trainee proficiency.This simulator represents a significant advancement in surgical training, with the potential to revolutionize the field by bridging the gap between virtual training and immersive haptic technology.