Improvement of plantar tactile sensitivity by stochastic resonance for prevention of falling

Author(s):  
Satoshi Kudoh ◽  
Ming Ding ◽  
Hirohsi Takemura ◽  
Hiroshi Mizoguchi
2013 ◽  
Vol 25 (6) ◽  
pp. 888-896 ◽  
Author(s):  
Satoshi Kudoh ◽  
◽  
Akira Obara ◽  
Yuu Satoh ◽  
Ming Ding ◽  
...  

This article reports on the results of experiments that involved the use of a wearable sensorimotor enhancement device for preventing falls. The brief exposure of the tactile receptors to sub-sensory vibration is known to enhance tactile sensitivity, a phenomenon called “stochastic resonance” (SR) in the somatosensory system. Applying white-noise vibration to a tarsal tunnel is thus expected to improve plantar tactile sensitivity and improve the stability of the standing posture and gait. A prototype of a wearable device is proposed as part of this research. Eleven healthy young subjects (22.6±0.6 years old) were recruited for the plantar tactile enhanced test. Twenty-one healthy elderly subjects (73.3±4.6 years old) were recruited for the standing posture stabilization and gait tests. The elderly subjects were separated into two groups, one being a high-sensitivity group, and the other being a low-sensitivity group. The plantar tactile sensitivity of the healthy young subjects was found to be significantly increased in the plantar tactile enhanced test (p < 0.05). The total sway length (p < 0.05), lateral range (p < 0.05), velocity variability (p < 0.05), lateral velocity variability (p < 0.05), and lateral acceleration variability (p < 0.05) of COP in the standing posture stabilizing test were found to be significantly lower in the elderly subjects when using the prototype device. The step length in the gait test with the device was significantly increased in the high-sensitivity elderly group (p < 0.05). The results of the plantar tactile enhanced test showed that the mechanical vibration noise applied to the tarsal tunnel by the developed prototype device can enhance the plantar tactile sensitivity. The results of the standing posture stabilizing test and the gait test showed that the device can improve the static and dynamic balance control ability of the elderly subjects. These results suggest that the proposed device offers the potential of reducing the risk of fall accidents among the elderly.


2015 ◽  
Vol 14 (02) ◽  
pp. 1550021 ◽  
Author(s):  
Manish Ranjit ◽  
Harshvardhan Gazula ◽  
Simon M. Hsiang ◽  
Patricia R. DeLucia

Stochastic resonance (SR) is a counterintuitive phenomenon in which additive noise enhances performance of a nonlinear system. Previous studies demonstrated SR effect on human tactile sensitivity by adding noise of same modality and cross modality. Similarly, enhancement of human hearing through additive noise has been studied. In this study, we investigate the effect of noise in visual perception, specifically time-to-contact (TTC) judgments. This study explores four research questions: (1) Does noise help in TTC judgments? (2) How does noise affect speed and accuracy of TTC judgments? (3) Does cross modal noise help in TTC judgments? (4) How does cross modal noise affect speed and accuracy of TTC judgments? Through simulation, we show that noise in optical cue can enhance weak signals. We also demonstrate that noise can improve speed of TTC judgments at the expense of accuracy. Similarly, we demonstrate SR by adding noise of cross modality. These findings provide plausible hypotheses regarding how much noise should be added to enhance TTC judgments.


2012 ◽  
Vol 2012 (0) ◽  
pp. _1P1-C02_1-_1P1-C02_4
Author(s):  
Yamato SUEDA ◽  
Yuichi KURITA ◽  
Minoru HATTORI ◽  
Masakazu TOKUNAGA ◽  
Hiroyuki EGI ◽  
...  

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 17011-17019
Author(s):  
Shohei Ikemura ◽  
Takahiro Endo ◽  
Fumitoshi Matsuno

Author(s):  
Domenico Pagliara ◽  
Maria Lucia Mangialardi ◽  
Stefano Vitagliano ◽  
Valentina Pino ◽  
Marzia Salgarello

Abstract Background After anterolateral thigh (ALT) flap harvesting, skin graft of the donor site is commonly performed. When the defect width exceeds 8 cm or 16% of thigh circumference, it can determine lower limb function impairment and poor aesthetic outcomes. In our comparative study, we assessed the functional and aesthetic outcomes related to ALT donor-site closure with split-thickness skin graft compared with thigh propeller flap. Methods We enrolled 60 patients with ALT flap donor sites. We considered two groups of ALT donor-site reconstructions: graft group (30 patients) with split-thickness skin graft and flap group (30 patients) with local perforator-based propeller flap. We assessed for each patient the range of motion (ROM) at the hip and knee, tension, numbness, paresthesia, tactile sensitivity, and gait. Regarding the impact on daily life activities, patients completed the lower extremity functional scale (LEFS) questionnaire. Patient satisfaction for aesthetic outcome was obtained with a 5-point Likert scale (from very poor to excellent). Results In the propeller flap group, the ROMs of hip and knee and the LEFS score were significantly higher. At 12-month follow-up, in the graft group, 23 patients reported tension, 19 numbness, 16 paresthesia, 22 reduction of tactile sensitivity, and 5 alteration of gait versus only 5 patients experienced paresthesia and 7 reduction of tactile sensitivity in the propeller flap group. The satisfaction for aesthetic outcome was significantly higher in the propeller flap group. Conclusion In high-tension ALT donor-site closure, the propeller perforator flap should always be considered to avoid split-thickness skin graft with related functional and aesthetic poor results.


2014 ◽  
Vol 2 ◽  
pp. 417-420
Author(s):  
Florian Gomez ◽  
Stefan Martignoli ◽  
Ruedi Stoop

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