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Comparing Muscle Activity and Younger and Older Users' Perceptions of Comfort When Using Sheet Switches for Electrical Appliances
Published in Marcelo M. Soares, Franscisco Rebelo, Advances in Usability Evaulation, 2013
Yasuhiro Tanaka, Yuka Yamazaki, Masahiko Sakata, Miwa Nakanishi
In addition, electromyography (EMG) was performed on the muscles in the participants’ forearms and hands to determine the physical characteristics of touch comfort and discomfort. On the basis of our previous study [18], the lumbrical muscles of the hand (Fig. 4), the flexor carpi ulnaris (FCU) muscles (Fig. 5), and the flexor carpi radialis (FCR) muscles (Fig. 6) were selected as the measurement points because these muscles reacted significantly when the sheet switch was touched. To eliminate individual errors and environmental effects, reference data were set prior to the testing trials in the following manner: In vertical touch testing, a digital force gauge that indicated the level of force in real time was set at the same height as the model switches, and the participants pressed it with a force of 10 N for 2 s. Then, the EMG data measured at the three points were used as reference data. Moreover, the instant at which the participants’ fingers touched a model switch was recorded using a digital video camera.
Tendon vibration changes perceived joint angle independent of voluntary body motion direction in virtual environments
Published in Advanced Robotics, 2021
Daiki Hagimori, Naoya Isoyama, Shunsuke Yoshimoto, Nobuchika Sakata, Kiyoshi Kiyokawa
The reason why the illusion was on the same side as the vibrating part was because TVR caused by muscle spindles was pronounced from the physiological point of view [28]. It has been reported that the amount of change in perceived angle differed by several degrees depending on vibrating parts [15] and that some participants experienced unintended direction of the illusion [27]. In terms of the experimental apparatus, this might be due to the pressure difference between the two sides of the wrist causing an elongation of the flexor carpi ulnaris and extensor carpi radialis. In this study, the actuator was attached to one side of the wrist only, and a wrist band was in direct contact with the other side. The wrist band pressed into the tendon on the side to which the actuator was attached in order to tighten the entire wrist. The elongation of the tendons may have caused passive wrist motion and affected the change in perceived angle caused by the kinesthetic illusion.
Single-channel surface electromyography (sEMG) based control of a multi-functional prosthetic hand
Published in Instrumentation Science & Technology, 2021
A sensitive band was designed using a force-sensitive resistor (FSR) for the measurement of muscular contractile force in terms of voltage. The FSR sensing area was encased in a 3D printed structure for proper distribution of this force across the contact surface area.[31,32]Figure S2a (Supplementary material) shows the sensing portion of the designed FSR band, and Figure S2b (Supplementary material) the voltage divider circuit for translating the change in resistance of FSR to the voltage output. The designed FSR band was attached to the flexor carpi ulnaris muscle on the forearm, as shown in Figure S2c (Supplementary material). Using the voltage from the FSR band, a maximum of six muscular contractile forces were defined in terms of percentage of maximum voluntary contraction (MVC) for recording EMG data. Table 1 describes the allocation of six levels of muscle contractions in which the sixth corresponds to MVC.
Factors affecting occlusion pressure and ischemic preconditioning
Published in European Journal of Sport Science, 2018
Henry Brown, Martyn J. Binnie, Brian Dawson, Nicola Bullock, Brendan R. Scott, Peter Peeling
With NIRS, no differences in arms were observed between cuffs for ΔHbO2 (small: −27.3 ± 6.6 µm vs. medium: −26.5 ± 8.5 µm; p = .837), ΔHHb (small: 46.5 ± 12.7 µm vs. medium: 48.0 ± 10.4 µm; p = .802) or Hbdiff (small: −73.8 ± 17.3 vs. medium: −74.5 ± 16.5; p = .935). Similarly, no differences in legs were observed between cuffs for ΔHbO2 (medium: −16.1 ± 9.1 µm vs. large: −21.1 ± 9.4 µm; p = .291), ΔHHb (medium: 22.2 ± 5.2 µm vs. large: 17.9 ± 4.7 µm; p = .097) or Hbdiff (medium: −37.5 ± 13.6 vs. large: −36.5 ± 12.0; p = .884) However, in arms compared to legs using the same cuff, significantly greater changes in arms were observed in ΔHbO2 (arm: −26.5 ± 8.2 µm vs. leg: −16.1 ± 9.1 µm; p = 0.030), ΔHHb (arm: 48.0 ± 10.4 µm vs. leg: 22.2 ± 5.2 µm; p < .001) and Hbdiff (arm: −74.5 ± 16.5 vs. leg: −37.5 ± 13.6; p < .001). The mean skinfold thickness was significantly lower at the forearm (flexor carpi ulnaris) (4.9 ± 1.1 mm) compared to the thigh (vastus lateralis) (11.1 ± 4.4 mm) (p = .002).