Tactile Apparent Movement Research Articles

Wearable lower limb haptic feedback device for retraining Foot Progression Angle and Step Width

Technological developments in the last decade have enabled the integration of sensors and actuators into wearable devices for gait interventions to slow the progression of knee osteoarthritis. Wearable haptic gait retraining is one area which has seen promising results for informing modifications of gait parameters for reducing knee adduction moments (KAM) during walking. Two gait parameters which can be easily adjusted to influence KAM include foot progression angle (FPA) and step width (SW). The purpose of this study was to: (1) determine whether a custom haptic ankle bracelet using binary vibrotactile and tactile apparent movement feedback could retrain ten healthy subjects to walk with a modified FPA and SW within a short training session with 80% accuracy; and (2) whether there was a difference between the number of steps required to complete the retraining task based on the two feedback schemes being tested. Retraining multiple gait parameters using a single device was a novel aspect of this work and we found that nine out of ten subjects were able to retrain their gait using the ankle bracelet in both feedback schemes to within 2° and 39mm of target FPA and SW respectively. We also found no difference in the number steps required for completion between the two schemes (p>0.05). Future research will investigate the device performance with patients with knee osteoarthritis and the effective change in KAM by modifying a combination of FPA and SW.

Control of body sway using a tactile device

The recognition of tactile apparent movement (AM) is normally a subjective sense. However, quantitative evaluation is necessary when applying tactile AM, an engineering system. In a previous study, we examined the body sway caused by tactile AM under fixed experimental conditions; however, the body-sway characteristics were not fully investigated. In this study, we investigate the body sway caused by tactile AM under fixed experimental conditions. We focused on biological information and body-sway movement, and compared cases where the apparent motion was recognized and not recognized. We propose the possibility of controlling body sway using tactile AM. Our findings will help improve the performance of systems that use tactile AM.

EMG analysis accompanied by tactile apparent movement

Tactile apparent movement recognition is normally considered as a subjective sense of humans. Applying the tactile apparent movement to an engineering system, a quantitative evaluation study becomes necessary. In previous studies, finding the body-sway caused by the tactile apparent movement in a fixed experimental condition became possible. However, characteristic of the body-sway was not thoroughly investigated. In this study, investigating the body-sway caused by tactile apparent movement in a fixed experimental condition was aimed. Therefore, we focused on biological information, the body-sway and the comparison between the apparent movement recognized trials and the non-recognized trials. The findings of this research will be conducive to optimize the performance of the systems that are using the tactile apparent movement.

Quantitative evaluation of body-sway caused by tactile apparent movement

The recognition of tactile apparent movement is normally a subjective sense. However, when applying tactile apparent movement to an engineering system, quantitative evaluation is necessary. In a previous study, we examined the body-sway caused by tactile apparent movement under fixed experimental conditions, but the body-sway characteristics were not fully investigated. In this study, we investigated the body-sway caused by tactile apparent movement under fixed experimental conditions. We focused on biological information and body-sway, and compared cases where the apparent motion was recognized and not recognized. Our findings will help to improve the performance of systems that use tactile apparent movement.

Mutual Information Analysis of Body Sway Accompanied by Tactile Apparent Movement

In this research, we examined a tactile sense for sensory substitution in people who have lost a certain sense. We considered use of apparent movement to communicate something via a tactile sense. It is necessary to measure a tactile apparent movement objectively and quantitatively because of an apparent movement is normally a subjective sense. This paper proposes the technique which measure the body sway accompanied by the recognition of a tactile apparent movement more securely. We examined the sway of body part by using EMGs around a shoulder, 3 axes acceleration data of the forearm, tracking data based on CCD camera of the upper part, and center of gravity sways of a person's body. By assuming a causal relationship between the sway of body part and EMGs, as an input and an output of the information channel, the transition probabilities and the averaged mutual information were obtained for 4 normal subjects. Moreover, relationship between a tactile apparent movement and tactile stimuli was investigated by the multiple comparison test. As a result, relevance with the body sway accompanied by the recognition of a tactile apparent movement and EMGs was evaluated quantitatively.

Characteristic Extraction of EMG with Recognition of Tactile Apparent Movement

In this report, we examined the relevance of the human physical oscillation and the recognition of the tactile apparent movement. EMGs caused by the human physical oscillation were measured in our research. Moreover, EMGs were analyzed by applying the short-time Fourier transform (STFT) and cluster analysis. As a consequence of comparing these analysis outputs with results of psychophysical experiment, the relevance of the human physical oscillation and the recognition of the tactile apparent movement was suggested.

Paradoxes in Tactile Adaptation. Focus on “Vibratory Adaptation in Cutaneous Mechanoreceptive Afferents” and “Time-Course of Vibratory Adaptation and Recovery in Cutaneous Mechanoreceptive Afferents”

Whenever we manipulate an object, or explore it using touch, sensory adaptation occurs in some form and this is likely to have an impact on perception and probably on sensorimotor control. Adaptation may be occurring at the level of the skin and receptor, at a central level, or some combination of the two. Although it has been known for many years that adaptation occurs (Berglund and Berglund 1970), its cause and nature remain uncertain. In the tactile system, usage of the term adaptation has been somewhat loose and potentially confusing. One common use is in the classification of neural responses. For example, rapidly adapting afferents (FAI or RA, and FAII or PC) respond only to the dynamic components of a stimulus applied to the skin, whereas slowly adapting afferents (SAI and SAII) respond to both the dynamic and static components of the stimulus (Talbot et al. 1968). This type of adaptation, or filtering, has a time course of the order of a second or less and is most likely attributable to the mechanics of the receptor (Loewenstein and Skalak 1966). The second—and markedly different—way in which adaptation has been used is most evident in the large number of psychophysical studies that show that a prolonged vibratory stimulus results in a decrease in the subject’s sensitivity to a subsequent vibratory stimulus (Berglund and Ber

The effect of frequency upon tactile apparent movement

Tactile apparent movement was observed under the conditions of variation in stimulus duration, frequency, and separation between two stimuli. First, optimal stimulus onset asynchrony (SOA) was determined as a function of stimulus duration using stimuli with the same frequency. Second, optimal SOA was estimated as a function of frequency, by using two stimuli with different frequencies. The optimal SOA for tactile apparent movement increased with the increases of stimulus duration. When two vibrators activate with the same frequency, the optimal SOA depends on frequency. The optimal SOA of the low-frequency stimulus (10 Hz) is longer than that of the high-frequency stimulus (250 Hz). If the first stimulus is 10 Hz and the second stimulus is 200 Hz, the optimal SOA is shorter than two stimuli with same frequency (10 Hz). The first stimulus was kept constant at 10 Hz and the second stimulus was varied in frequency. As the frequency-difference increases, the optimal SOA is decreased, but at the second stimulus of 80 Hz, the optimal SOA is similar to that of two stimuli of 200 Hz. These findings suggest that there are interactions between two channels. [Work supported by the Ministry of Education, Science and Culture, No. 62810008.]

Topographic Properties of Somatosensory Evoked Potentials Associated with Tactile Apparent Movement

Topographic Properties of Somatosensory Evoked Potentials Associated with Tactile Apparent Movement

Tactile apparent movement: the effects of shape and type of motion.

Judgments of tactile apparent movement were obtained from six subjects for a variety of tactile spatiotemporal stimulus patterns (moving points and lines, rotating lines, and expanding squares, boundaries, and holes). Each of these patterns was presented by means of three different numbers of steps used to trace the pattern over time. Stimulus duration and interstimulus onset interval (ISOI) were varied to determine the temporal conditions required for good tactile apparent movement. In general, pattern shape and type of movement (linear, rotating, expanding) had little effect on the temporal conditions for good apparent movement or on the interactions among the other variables. Increasing the number of steps in a pattern decreased the ISOI required for good apparent movement, but had no effect on the range of ISOIs over which good movement was obtained. Increases in stimulus duration increased the ISOI required for good tactile apparent movement, in agreement with earlier studies, and increased as well the range of ISOIs over which good movement was obtained.

The effect of number of stimulators on the optimal interstimulus onset interval in tactile apparent movement

The effect of variations in the number of sequentially activated electromechanical stimulators on tactile apparent movement was examined in nine subjects. Judgments of successiveness or simultaneity were obtained as well. It was observed that four stimulators produced more frequent reports of apparent movement and resulted in optimal movement at shorter interztimulus onset intervals than did two stimulators, regardless of stimulus duration. Stimulus duration and interstimulus onset interval and their interaction were again found to be important determinants of tactile apparent movement.

Tactile apparent movement: The effects of interstimulus onset interval and stimulus duration

The effects of variations in stimulus duration and interstimulus onset interval on ratings of tactile apparent movement were determined for seven Ss with stimulators of very small diameter. Judgments of successiveness and simultaneity were also obtained. It was found that apparent movement increased as a power function of increases in stimulus duration. The function relating tactile apparent movement and stimulus duration was shown to be similar to that obtained by Kolers (1964) for visual apparent movement, lnterstimulus onset interval also had a marked effect on apparent movement, and the optimal interval was influenced by stimulus duration in a manner similar to that reported by Sherrick and Rogers (1966).

Tactile apparent movement: the effects of number of stimulators.

Tactile apparent movement: the effects of number of stimulators.