A white cane is conventionally used by visually impaired persons to assist their mobility. To learn its proper operation, training by an orientation & mobility specialist is necessary. However, ...because the number of specialists is limited, visually impaired persons often do not receive sufficient training. To rectify this issue, a training environment in which the visually impaired can train independently is required. This paper proposes a training system that enables the visually impaired to learn white cane techniques using illusory pulling cues. Specifically, in the white cane touch technique, which is a basic white cane technique, a system that targets the swing width of the white cane is presented by illusory pulling cues. To verify the efficacy of the system, a prototype was implemented and evaluated via user tests. The results confirmed that the error of the swing width of the white cane decreased following use of the proposed system. The proposed system will contribute to the development of the mobility of the visually impaired by enabling them to train with the white cane independently and spontaneously, thereby reducing the workload of specialists.
This study aimed to identify the physical factors contributing to the perception of the hardness of objects tapped using white canes, which are commonly used by the visually impaired for autonomous ...walking. First, physical factors such as vibration tapping sounds and reaction forces were measured during the indirect tapping of rubber sheets with different hardness using a white cane. Second, we determined the relationship between the subjective hardness perceived by the visually impaired individuals and the physical factors through multivariate analysis. In addition, we estimated the contribution of each factor. The result indicates that the white cane vibrated at similar frequencies during tapping even when the hardness of objects changed. In contrast, the tapping sound varied widely with the variation of the hardness of the rubber sheet. In addition, the peak values of the reaction forces significantly changed depending on the hardness. Based on the results of the multivariate analysis, the contributions of tapping sounds and reaction forces to hardness perception were remarkable. In contrast, the contributions of vibrations could not be found using our analytic method. These findings will help in the design and evaluation of support equipment for the visually impaired.
White canes are widely used as tools to assist visually impaired persons to walk. The white cane is used to acquire environmental information as a clue for walking. It is important to know what ...information can be acquired by using the cane, how accurate the acquired information is, and how we can improve the information and accuracy. Clarification of these questions would contribute to development of white canes that enable better acquisition of environmental information. It would also assist in the design of buildings with appropriate guidance for visually impaired persons on the basis of information acquired through the canes. In this study, in order to acquire basic knowledge about hardness recognition, experiments were performed using four conditions: 1) Tapping or pushing the object with the index finger tip and white cane tip, 2) use or non-use of the auditory sense to study its usefulness, 3) different ways of grasping the cane, and 4) different number of checks. Nine visually impaired persons who usually walked alone using white canes participated in the experiments. They estimated the hardness of a rubber sheet under various combinations of the operation conditions and hearing conditions. Results showed that the number of checks had little effect on the user’s estimation of the hardness of the sheet. For the recognition of the contact target hardness using the white cane, it was effective to simultaneously use information from different modalities, namely tactile and auditory information. We also observed that, when pushing the cane with the index fingers, the users could feel the objects as if they had directly touched them with the fingers.
Visually impaired people widely use white canes to walk alone. To learn a proper operation of a white cane, training by orientation & mobility (O & M) specialists is required. However, due to the ...influence of recent pandemic with COVID-19 in addition to the shortage of O & M specialists, visually impaired cannot be enough trained by social distancing. Therefore, we propose a force feedback training system that visually impaired learn white cane technique using haptic illusion. Specifically, in the touch technique which is one of the basics of white cane technique, a system that target swing of the white cane was presented by illusory pulling cues was developed. In this study, a basic concept of the system is discussed and a prototype system is implemented.
Visually impaired people widely use white canes to walk alone. To learn a proper operation of a white cane, training by orientation & mobility (O & M) specialists is required. However, due to the ...influence of recent pandemic with COVID-19 in addition to the shortage of O & M specialists, visually impaired cannot be enough trained by social distancing. Therefore, we propose a force feedback training system that visually impaired learn white cane technique using haptic illusion. Specifically, in the touch technique which is one of the basics of white cane technique, a system that target swing of the white cane was presented by illusory pulling cues was developed. In this study, a basic concept of the system is discussed and a prototype system is implemented.
Visually impaired people widely use white canes to obtain information from the surrounding environment and thereby walk alone. Clarifying the information presented by current white canes could enable ...the development of a new white cane with improved usability. Previous studies have reported that the visually impaired can better perceive the hardness of objects by using both hearing and tactile sensations when indirectly tapping objects using the white cane. The white cane and objects vibrate at the resonance frequency when they are tapped. The vibration of the white cane is expected to be detected through tactile sensations, and that of objects is converted into acoustic information and is detected through hearing. In this study, we identified the physical factors contributing to the hardness perception of objects during indirect tapping using white canes. Measurements of the frequency characteristics of the vibration and acoustic information revealed that the similarity of frequency characteristics for different hardness values of objects was lower for acoustic information than for vibration information. This result supports previous study results that reported that hearing is dominant in indirect tapping using white canes.
Manual operations of the hydraulic jack device can become ergonomic stressors for the musculoskeletal system because of the required operational forces, muscle activities, or working postures. ...However, the usability of the hydraulic jack has not been fully explored for non-professional personnel.
To evaluate the musculoskeletal loads during manual operations of a hydraulic jack based on the ergonomic postural analysis and electromyographyMETHODS:Nine men operated the lever of a hydraulic jack with three positions: parallel to and near (P-N), parallel to and far from (P-F), and orthogonal to the jack lever (O). Postural loads were evaluated by Loading on the Upper Body Assessment (LUBA), an ergonomic observational method, and were classified into action categories. The surface electromyogram of eight muscles and the subjective sense of burden were also measured.
The initial force for lever pushing reached 40-80 N and exceeded the recommended forces for the unusual postures. The overall assessment of LUBA showed that 31% of working postures observed in O position require immediate consideration and corrective action and the maximum holding time estimated was < 1 minute. The postural load increased due to the shoulder joint abduction in the P-F and O positions and due to the trunk rotation in O position.
The results suggest that operating the hydraulic jack cause considerable postural loads and manual forces insufficient for several minutes of manual task. Therefore, improving working methods and tool designs are needed to improve usability and decrease the risk of musculoskeletal disorders during jack operations.
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IZUM, KILJ, NUK, OILJ, PILJ, SAZU, UL, UM, UPUK, VSZLJ
There have been various types of navigation systems for the visually impaired. Many of them were designed to help the visually impaired walk long distances between large landmarks, such as houses and ...stations. Moreover, short distance navigation is required for the visually impaired. For example, consider a situation where a visually impaired person moves from a table to a counter in a food court. First, he/she can move roughly, but, near the counter, he/she needs to walk carefully not to collide with or pass through the counter. To the best of our knowledge, such a precise navigation has not been focused on in the past. In this study, we proposed a navigation device for precise walking of the visually impaired. The system comprises a white cane and a small vibration actuator embedded in the grip of the white cane. The actuator can generate asymmetric vibrations, enabling the user to feel a pulling illusion. Using this mechanism, the device can notify the user about the directions to walk. In addition, the actuator is so small and light that the user can use the device with one hand, such as the conventional white cane. Besides, we conducted a user study where two sighted participants who wore eye masked and three visually impaired participants walked 10 m to reach a target destination in a corridor environment to evaluate the proposed device's effectiveness. Based on the results, the device can guide the user precisely.
The purpose of this study is to examine the variability in sensory test of tactile results using Semmes-Weinstein monofilament (SWM). At present, several methods for measuring the tactile sensitivity ...are clinically used in diabetic peripheral neuropathy screening. One of these methods is a touch test that uses a device with nylon SWMs, i.e., SWMs embedded in a plastic handle. A small pushing force is applied at the handle to bow the filaments. Because of its ease and simplicity, the SWM test is conducted at the patient's bedside in a hospital. However, previous studies have reported some problems with this test. Studies have shown variations in the measured data, and it is uncertain whether these variations are caused by mechanical properties of the nylon fiber or by the motion of the operator's hands. We carried out two experiments to examine the effect of (1) the variability caused by the human operator conducting the SWM test on the test results and (2) the number of compressions of the SWM on the test results. In experiment 1, we measured the velocity of the operator's hand motion and the buckling force of the SWMs. The results showed variability in the hand motion of the operator conducting the SWM tests. In experiment 2, we measured the buckling force of the SWMs under a controlled velocity. We compared the buckling force of the SWMs through a number of trials. These results showed that the buckling force gradually decreases as the number of test cycles increase. In conclusion, we find that the accuracy of the SWM tests is a factor of the number of test cycles. Additionally, manual training for standardizing skills of medical staff members needs to be developed. Furthermore, the characteristics of the SWMs deteriorated over time. In future work, we aimto find a solution to minimize the variability in the SWM test results and develop a new testing system that uses tactile sensibility for diabetic peripheral neuropathy screening.
We have conducted research to obtain fundamental knowledge of the exploration methods used to perceive the characteristics of an object through contact with a white cane. The research has enabled us ...to examine methods that enhance the accuracy of perceiving objects and the materials and design of a white cane. In this study, we examine whether or not the method of grasping a white cane affects weight perception, with 5 visually impaired people who use white canes in their daily lives as participants. The participants provide estimates for the magnitudes of six weights ranging from 500 g to 1,000 g in steps of 100 g. Results indicate that weight can be determined using a white cane, even though this method is slightly inferior to directly pushing the weight by hand. The weight perception obtained by employing a white cane is not affected by the manner of grasping the cane.
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