Virtual Tactile Simulation: A Novel Display and the Effects on Users’ Texture Perception

2012 ◽  
Author(s):  
Margherita Peruzzini ◽  
Maura Mengoni ◽  
Michele Germani
Keyword(s):  
Experimental Testing ◽  
Mechanical Vibration ◽  
Tactile Display ◽  
Class Discrimination ◽  
Tactile Stimuli ◽  
Real Material ◽  
Simulation Strategy ◽  
Material Texture ◽  
Electrical Stimuli ◽  
Tactile System

This paper presents a novel study on the simulation of material texture by means of electro-tactile stimuli and details the effects on the users’ ability to recognize and discriminate different material classes. The research exploits a novel tactile display to simulate material texture and validates the adopted simulation strategy by experimental testing. The tactile system elaborates data from real material samples and combines electrical stimuli and mechanical vibration to reproduce both roughness and texture coarseness sensations. Then, an experimental protocol based on the theory of Psychophysics is defined to carry out system calibration and tests with users. The research aims at validating the proposed simulation strategy and checking the user response on virtual tactile stimuli. Experimentations were carried out to reproduce virtual material texture and measure the users’ ability to distinguish different virtual materials and to recognize the material class. Experimental results provide interesting details about tactile perception mechanisms and validate the adopted approach for tactile signals’ recognition and material class discrimination.

scholarly journals Fundamental Perceptual Characterization of an Integrated Tactile Display with Electrovibration and Electrical Stimuli

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 301 ◽  
Author(s):  
Seiya Komurasaki ◽  
Hiroyuki Kajimoto ◽  
Hiroki Ishizuka
Keyword(s):  
Single Stimulus ◽  
Tactile Display ◽  
Micro Fabrication ◽  
Tactile Displays ◽  
Tactile Stimuli ◽  
Friction Pressure ◽  
Electrical Stimuli ◽  
The Relationship

Tactile displays have been widely studied for many decades. Although multiple tactile stimuli are more effective to improve the quality of the presented tactile sensation, most tactile displays provide a single tactile stimulus. An integrated tactile display with electrovibration and electrical stimuli is proposed herein. It is expected that vibrational friction, pressure and vibration can be presented at the same time through the tactile display. Also, these stimuli only require electrodes for stimulation. Therefore, the tactile display can be easily miniaturized and densely arrayed on a substrate. In this study, a tactile display is designed and fabricated using the micro-fabrication process. Furthermore, the display is evaluated. First, the relationship between a single stimulus and the perception is investigated. The electrovibration and electrical stimuli have a frequency dependence on perception. Second, whether the multiple stimuli with the electrovibration and electrical stimuli are perceivable by the subjects is also evaluated. The results indicate that the multiple tactile stimuli are perceivable by the subjects. Also, the possibility that the electrovibration and electrical stimuli affect each other is confirmed.

A Method for Roughness and Texture Simulation via Tactile Displays

2011 ◽  
Author(s):  
Maura Mengoni ◽  
Paolo Morichetti ◽  
Margherita Peruzzini ◽  
Michele Germani
Keyword(s):  
Mechanical Vibration ◽  
Synthesis Method ◽  
Software Tool ◽  
Tactile Display ◽  
System Response ◽  
Good Reliability ◽  
Tactile Displays ◽  
Real Material ◽  
Selection Of ◽  
Skin Mechanoreceptors

This paper presents a tactile synthesis method to provide roughness and texture coarseness sensations using a selective stimulation approach implemented by a tactile display. Digitizing, elaborating and processing real material surfaces obtain signals. The selection of their frequency range is based on the reactive frequencies of SAI and FAI types receptors. An electro-tactile display provided with a mechanical vibration to stimulate FAII units located at the deeper skin layers has been developed. A SW tool allows to manage selective signals modulation and configuration according to the displayed material. The research aims at overcoming a crucial problem concerning the signals adopted by most electro-tactile displays to stimulate skin mechanoreceptors. The paper focuses on the description of the adopted method and of the implemented software tool to control the tactile display. Preliminary experimentations were carried out to measure the system’s latency, accuracy and reliability. Experimental sessions show a promising system response: minimal latency (30ms), good reliability (>98%) and acceptable accuracy (>70%).

scholarly journals The anticipation and perception of affective touch in women with and recovered from Anorexia Nervosa

2020 ◽  
Author(s):  
Laura Crucianelli ◽  
Benedetta Demartini ◽  
Diana Goeta ◽  
Veronica Nisticò ◽  
Alkistis Saramandi ◽  
...  
Keyword(s):  
Anorexia Nervosa ◽  
Reward Processing ◽  
Healthy Controls ◽  
Top Down ◽  
Ct Afferents ◽  
Tactile Stimuli ◽  
Successful Recovery ◽  
Secondary Result ◽  
Ct System ◽  
Tactile System

AbstractDisruptions in reward processing and anhedonia have long being considered as possible contributors to the aetiology and maintenance of Anorexia nervosa (AN). Recently, interoceptive deficits have also been observed in AN, including reduced tactile pleasure. However, the extent to which this tactile anhedonia is specifically liked to an impairment in a specialized, interoceptive C tactile system originating at the periphery, or a more top-down mechanism in the processing of pleasant tactile stimuli remains debated. Here, we investigated two related hypotheses. First, we examined whether the differences, between patients with AN and healthy controls in the perception of pleasantness of touch stimuli delivered in a CT-optimal manner versus a CT non-optimal manner would also be observed in patients recovered from AN. This is important as tactile anhedonia in acute patients may be the secondary result of prolonged malnutrition, rather than a deficit that contributed to the development of the disorder. Second, we examined whether these three groups would also differ in their top-down, anticipatory beliefs about the perceived pleasantness of different materials touching the skin, and to what degree such top-down beliefs and related impairments in alexithymia and interoceptive sensibility would explain any differences in perceived tactile plesantness. To this end, we measured the anticipated pleasantness of various materials touching the skin and the perceived pleasantness of light, dynamic stroking touches applied to the forearm of 27 women with AN, 24 women who have recovered and 30 healthy controls using C Tactile (CT) afferents-optimal (slow) and non-optimal (fast) velocities. Our results showed that both clinical groups anticipated tactile experiences and rated delivered tactile stimuli as less pleasant than healthy controls, but the latter difference was not related to the CT optimality of the stimulation. Instead, differences in how CT optimal touch were perceived were predicted by differences in top-down beliefs, alexithymia and interoceptive sensibility. Thus, this study concludes that tactile anhedonia in AN is not the secondary result of malnutrition but persists as a trait even after otherwise successful recovery of AN and also it not linked to a bottom-up interoceptive deficit in the CT system, but rather to a learned, defective top-down anticipation of pleasant tactile experiences.

scholarly journals A P300 Brain-Computer Interface Paradigm Based on Electric and Vibration Simple Command Tactile Stimulation

2021 ◽  
Vol 15 ◽  
Author(s):  
Chenxi Chu ◽  
Jingjing Luo ◽  
Xiwei Tian ◽  
Xiangke Han ◽  
Shijie Guo
Keyword(s):  
Spatial Information ◽  
Brain Computer Interface ◽  
Learning Ability ◽  
Computer Interface ◽  
New Paradigm ◽  
Common Spatial Pattern ◽  
Frequency Information ◽  
Tactile Stimuli ◽  
Average Accuracy ◽  
Electrical Stimuli

This paper proposed a novel tactile-stimuli P300 paradigm for Brain-Computer Interface (BCI), which potentially targeted at people with less learning ability or difficulty in maintaining attention. The new paradigm using only two types of stimuli was designed, and different targets were distinguished by frequency and spatial information. The classification algorithm was developed by introducing filters for frequency bands selection and conducting optimization with common spatial pattern (CSP) on the tactile evoked EEG signals. It features a combination of spatial and frequency information, with the spatial information distinguishing the sites of stimuli and frequency information identifying target stimuli and disturbances. We investigated both electrical stimuli and vibration stimuli, in which only one target site was stimulated in each block. The results demonstrated an average accuracy of 94.88% for electrical stimuli and 95.21% for vibration stimuli, respectively.

scholarly journals Sharpness Recognition Based on Synergy between Bio-inspired Nociceptors and Tactile Mechanoreceptors 

2021 ◽  
Author(s):  
Adel Parvizi-Fard ◽  
Nima Salimi-Nezhad ◽  
Mahmood Amiri ◽  
Egidio Falotico ◽  
Cecilia Laschi
Keyword(s):  
Receptive Fields ◽  
Tactile Sensor ◽  
Feedback Mechanism ◽  
Tactile Feedback ◽  
Temporal Coding ◽  
Control Mechanisms ◽  
Sensory Afferents ◽  
Tactile Stimuli ◽  
Tactile System ◽  
The Impact

Abstract Touch and pain sensations are complementary aspects of daily life that convey crucial information about the environment while also providing protection to our body. Technological advancements in prosthesis design and control mechanisms assist amputees to regain lost function but often they have no meaningful tactile feedback or perception. In the present study, we propose a bio-inspired tactile system with a population of 23 digital afferents: 12 RA-I, 6 SA-I, and 5 nociceptors. Indeed, the functional concept of the nociceptor is implemented on the FPGA for the first time. One of the main features of biological tactile afferents is that their distal axon branches in the skin, creating complex receptive fields. Given these physiological observations, the bio-inspired afferents are randomly connected to the several neighboring mechanoreceptors with different weights to form their own receptive field. To test the performance of the proposed neuromorphic chip in sharpness detection, a robotic system with three-degree of freedom equipped with the tactile sensor indents the 3D-printed objects. Spike responses of the biomimetic afferents are then collected for analysis by rate and temporal coding algorithms. In this way, the impact of the innervation mechanism and collaboration of afferents and nociceptors on sharpness recognition are investigated. Our findings suggest that the synergy between sensory afferents and nociceptors conveys more information about tactile stimuli which in turn leads to the robustness of the proposed neuromorphic system against damage to the taxels or afferents. Moreover, it is illustrated that spiking activity of the biomimetic nociceptors is amplified as the sharpness increases which can be considered as a feedback mechanism for prosthesis protection. This neuromorphic approach advances the development of prosthesis to include the sensory feedback and to distinguish innocuous (non-painful) and noxious (painful) stimuli.

A Simulation Strategy on the Quasi-Static Axial Crushing Process of Composite Tubes Based on LS-DYNA

2014 ◽  
Vol 1082 ◽  
pp. 351-358
Author(s):  
Zhi Jie Li ◽  
Guo Qing Yuan ◽  
David Hui ◽  
Zhe Min Jia
Keyword(s):  
Peak Load ◽  
Displacement Curve ◽  
Structural Failure ◽  
Composite Tubes ◽  
Material Density ◽  
Real Material ◽  
Simulation Strategy ◽  
Simulation Results ◽  
The Stability ◽  
The Given

Based on the code LS-DYNA, the simulation strategy on the quasi-static crushing process of composite tubes is studied by conducting two series of comparison simulations: one is at different virtual loading speeds with the real material density and the other is with different virtual material densities at the given loading speed. The simulation results are summarized as three types, namely mode-varying type (MVT), unstable type (UT) and stable type (ST), depending on the change of the structural failure mode and the occurrence of the load-fluctuating stage in the load-displacement curve. Analysis has shown that the steady load possesses the stability, the peak load has the convergence zone, and the thresholds of energy ratio can be adopted to evaluate the simulation results. In the end, the simulation strategy is proposed to makes it possible to acquire the simulation results with a higher query precision at a lower computing cost.

scholarly journals Scissors-Type Haptic Device Using Magnetorheological Fluid Containing Iron Nanoparticles

Technologies ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 26 ◽  
Author(s):  
Mioto Waga ◽  
Yuuki Aita ◽  
Junichi Noma ◽  
Takehito Kikuchi ◽  
Yoshimune Nonomura
Keyword(s):  
Evaluation System ◽  
Mechanical Response ◽  
Magnetorheological Fluid ◽  
Tactile Display ◽  
Haptic Device ◽  
Mechanical Stimuli ◽  
Mr Fluid ◽  
Tactile Stimuli ◽  
Simulation Systems ◽  
Force Profiles

The mechanical ability and usefulness of simulation systems can be improved by combining a tactile display with a remote control or medical simulation systems. In this study, a scissors-type haptic device containing magnetorheological fluid (MR fluid) in its fulcrum is developed. We evaluate the mechanical response to the applied voltage and realize the presence of mechanical stimuli when a subject grasps or cuts the corresponding objects. When the magnetic field around the MR fluid is controlled by an electric voltage of 150–500 mV, the torque linearly increases from 0.007 ± 0.000 to 0.016 ± 0.000 N m. The device can provide tactile stimuli with 0.1 s of resolution. We also determined the voltage profiles based on typical force profiles obtained during grasping/cutting processes and evaluated the torque using a mechanical evaluation system. Features of the force profiles related to the soft and sticky feels were reconstructed well.

Artificial Sensibility Based on the Use of Piezoresistive Sensors

1998 ◽  
Vol 23 (5) ◽  
pp. 620-626 ◽  
Author(s):  
G. LUNDBORG ◽  
B. ROSÉN ◽  
K. LINDSTRÖM ◽  
S. LINDBERG
Keyword(s):  
Median Nerve ◽  
Spatial Resolution ◽  
Myoelectric Prosthesis ◽  
Potential Value ◽  
Piezoresistive Sensors ◽  
Pinch Grip ◽  
Skin Electrodes ◽  
Tactile Stimuli ◽  
Electrical Stimuli ◽  
Different Levels

Piezoresistive sensors, applied to the fingertips of non-sensate fingers, were used for the detection of touch and pressure in four patients with recent median nerve repairs, and in one patient using a myoelectric prosthesis. The signals from the sensors, produced by the tactile stimuli, were processed and transposed as electrical stimuli to sensate skin of the ipsi- or contralateral arm by the use of skin electrodes. With this setup the test subjects could rapidly learn to differentiate between tactile stimuli applied to different fingers, thereby regaining spatial, resolution in the hand. All five patients rapidly improved their ability to regulate the power of pinch grip without the help of vision. The patient with a hand prosthesis rapidly learned to discriminate between four different levels of pressure, applied to the thumb by four different Semmes-Weinstein monofilaments (75, 125, 280 and 450 g). These results indicate that the system is of potential value for patients lacking sensibility or using prostheses.

Differential Controls Over Tactile Detection in Humans by Motor Commands and Peripheral Reafference

2006 ◽  
Vol 96 (3) ◽  
pp. 1664-1675 ◽  
Author(s):  
C. Elaine Chapman ◽  
Evelyne Beauchamp
Keyword(s):  
Time Course ◽  
Index Finger ◽  
Motor Command ◽  
Electromyographic Activity ◽  
Backward Masking ◽  
Motor Tasks ◽  
Motor Commands ◽  
Tactile Stimuli ◽  
Tactile Detection ◽  
Electrical Stimuli

The purpose of this study was to determine the extent to which motor commands and peripheral reafference differentially control the detection of near-threshold, tactile stimuli. Detection of weak electrical stimuli applied to the index finger (D2) was evaluated with two bias-free measures of sensory detection, the index of detectability ( d′) and the proportion of stimuli detected. Stimuli were presented at different delays prior to and during two motor tasks, D2 abduction, and elbow extension; both tasks were tested in two modes, active and passive. For both active tasks, the peak decrease in tactile suppression occurred at the onset of electromyographic activity. The time course for the suppression of detection during active and passive D2 abduction was identical, and preceded the onset of movement (respectively, −35 and −47 ms). These results suggest that movement reafference alone, acting through a mechanism of backward masking, could explain the modulation seen with D2 movement. In contrast, tactile suppression was significantly earlier for active elbow movements (−59 ms) as compared with passive (−21 ms), an observation consistent with both the motor command and peripheral reafference contributing to the suppression of detection of stimuli applied to D2 during movements about a proximal joint. A role for the motor command in tactile gating during distal movements cannot be discounted, however, because differences in the strength and distribution of the peripheral reafference may also have contributed to the proximo-distal differences in the timing of the suppression.

scholarly journals Unmyelinated Afferents Constitute a Second System Coding Tactile Stimuli of the Human Hairy Skin

1999 ◽  
Vol 81 (6) ◽  
pp. 2753-2763 ◽  
Author(s):  
Å. B. Vallbo ◽  
H. Olausson ◽  
J. Wessberg
Keyword(s):  
Human Subjects ◽  
General Distribution ◽  
High Threshold ◽  
Skin Deformation ◽  
Face Area ◽  
Hairy Skin ◽  
Tactile Stimuli ◽  
Forearm Skin ◽  
Low Threshold ◽  
Tactile System

Unmyelinated afferents constitute a second system coding tactile stimuli of the human hairy skin. Impulses were recorded from unmyelinated afferents innervating the forearm skin of human subjects using the technique of microneurography. Units responding to innocuous skin deformation were selected. The sample ( n = 38) was split into low-threshold units ( n = 27) and high-threshold units ( n = 11) on the basis of three distinctive features, i.e., thresholds to skin deformation, size of response to innocuous skin deformation, and differential response to sharp and blunt stimuli. The low-threshold units provisionally were denoted tactile afferents on the basis of their response properties, which strongly suggest that they are coding some feature of tactile stimuli. They exhibited, in many respects, similar functional properties as described for low-threshold C-mechanoreceptive units in other mammals. However, a delayed acceleration, not previously demonstrated, was observed in response to long-lasting innocuous indentations. It was concluded that human hairy skin is innervated by a system of highly sensitive mechanoreceptive units with unmyelinated afferents akin to the system previously described in other mammals. The confirmation that the system is present in the forearm skin and not only in the face area where it first was identified suggests a largely general distribution although there are indications that the tactile C afferents may be lacking in the very distal parts of the limbs. The functional role of the system remains to be assessed although physiological properties of the sense organs invite to speculations that the slow tactile system might have closer relations to limbic functions than to cognitive and motor functions.

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