著者

坂口 歳斗 土井 幸輝 西村 崇宏 藤本 浩志

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.863, pp.18-00119, 2018 (Released:2018-07-25)

参考文献数

29

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Acupuncturists determine muscle stiffness by pressing their fingers down. To shorten the palpation time and minimize discomfort to the patient, a good palpation technique is required to determine the stiffness of the patient's muscles with as few presses as possible. However, palpation is dependent on the experience of the practitioner. Therefore, an investigation of human hardness discrimination characteristics is necessary to provide some quantitative guidance. In this study, to determine the relationship between different numbers of presses and the accuracy of discriminating hardness, we investigated the differential threshold of hardness for different numbers of presses (1, 3, or 5). We used 7 elastic test pieces, each with a different Young's modulus, as the presented stimuli. We conducted an experiment using the constant stimuli method to calculate the differential threshold of hardness as an evaluation index of hardness identification. In the experiment, the participants repeatedly pressed for either 1, 3, or 5 sets by using 2 presented stimuli and then distinguished the hardness of the stimuli. The results of the experiment showed that when the pressing forces were 5 and 10 N, as the number of presses decreased, the differential threshold of hardness increased. However, when the pressing force was 15 N, the differential threshold of hardness was small regardless of the number of indentations. This knowledge will be useful for the improvement of the palpation technique in acupuncture schools. For example, the index of the hardness discrimination characteristic used in this study may be used as a quantitative numerical target and for performance evaluation.

著者

坂口 歳斗 土井 幸輝 藤本 浩志

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.851, pp.17-00059-17-00059, 2017 (Released:2017-07-25)

参考文献数

23

被引用文献数

1

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Hardness identification is one of the most important tactile senses in humans. People use their hands in various ways to identify the hardness of an object. For example, acupuncturists identify stiffness in a muscle by pressing down with their forefinger held flat over the affected area. However, experimental evidence for the role of the pressing method in the identification of an object's hardness even when the same finger is used has not been shown yet. In this fundamental study, we investigated the differential threshold of hardness for different finger postures of pressing (pressing down with one's forefinger held “flat” or “vertically”) to determine the relationship between the different finger postures of pressing and hardness identification. We used seven elastic test pieces, each with a different Young's modulus, as the presented stimuli. We conducted an experiment using the constant method to calculate the differential threshold of hardness as a measure of hardness identification. The results showed that the differential threshold of hardness was higher when pressing down with a forefinger held “flat” than when pressing down “vertically” with the same force. This finding will be useful in evaluating the tactile identification of hardness in acupuncturists.