Vol.7 No.4 2015

Research paper : Mental fatigue measurement as application software on consumer devices (S. IWAKI et al.)−217−Synthesiology - English edition Vol.7 No.4 (2015) Management Co., Ltd, a venture company that received technological transfer from AIST. Engages in research on the effect of information factors in the environment using 1/f fluctuation on brain functions, and on the business of intellectual rights of this research result and its technological diffusion. In this paper, was in charge of the verification experiment for the simple fatigue measurement system that can be used in daily life, the implementation for commercial use, and the collection of actual measurement data in real work environment.Discussions with ReviewersOverall comment (Motoyuki Akamatsu, AIST)The manuscript describes the technological development that enables the users themselves to execute the flicker fatigue test, which had been used as a method of experimental fatigue measurement, in daily life, and also addresses the practical application of this technology. The scenario for the technological development describes how a technology used in academic research could now be used widely in society, and this is appropriate as a paper of Synthesiology.1 Point of technological breakthroughComment (Motoyuki Akamatsu)You explain one of the technological breakthrough points of using contrast instead of frequency, and I think the characteristic of this technology will become clearer if you expand more on this point. By just adding a sentence, “By utilizing the aforementioned characteristic, it is possible to measure the change in flicker perception caused by fatigue by changing the contrast, even in devices with fixed display frequency,” I think you can emphasize that this, in fact, is the breakthrough point.Answer (Sunao Iwaki)Based on your comment, I added two sentences that briefly explain the point of breakthrough in using the contrast threshold for flicker perception at the end of paragraph 2 of subchapter 3.1.2 Conventional fatigue measurementComment: (Katsuhiko Sakaue, Environment and Safety Headquarters, AIST)In paragraph 3 of chapter 1, it is written that it is impossible for the general users to readily use the fatigue measurement based on objective index in daily life, but you do not address the perception and cognition indices that are the main subjects of this paper. Although it is explained in the following chapters, I think you should mention them in the same rank as other objective indices in this paragraph. It can be a brief summary, but please make some additions.Answer (Sunao Iwaki)As you indicated, I added the descriptions on perception and cognitive indices in chapter 1.3 Index for flicker fatigue test using this methodQuestion (Motoyuki Akamatsu)The vertical axis of Fig. 9 is different from other diagrams. Is this because the index value of fatigue has been established in the flicker fatigue test using frequency, but the value to be used as the index when using contrast has not been established?Answer (Sunao Iwaki)In the preliminary data obtained during the continuous use of our system in daily life as shown in Fig. 9, unlike the laboratory experiment where various parameters are controlled, there is no established method for explicitly setting the “standard value” (data that serves as the basis to normalize data with large personal variance; normally the measurement value before fatigue load is set as the standard value). This time, the largest value measured during the experimental period was set as the “standard value,” and the vertical axis of the graph was corrected so it will match the other graphs.Also, a method to determine the “standard value” from the previously acquired fatigue data is thought to be an important point in practical application, and this could be a focus of future development which is being studied with the AIST venture company for technology transfer. I added paragraph 3 of chapter 3 to explain this point.


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