手首及び腰でのハンガー反射 (Hanger Reflex at Wrist and Waist)

同様の現象が生じるかどうかの検証はなされていなかった。我々は今回、ふとん用洗濯バサミで手首及び腰を挟むと同様に不随意に回旋することを見出した。これはハンガー反射に用いられている手法を体全体に拡張することで、効率的に不随意運動を誘発できる可能性を示唆している。本稿では手首及び体幹を圧迫するデバイス開発について報告する。ユーザーテストの結果大半の被験者が回旋方向への力を感じることを確認した。さらにギプスの圧迫によって生じる皮膚のせん断変形が現象発生に関与している可能性が示唆された。

When a head is equipped with a hanger made of wire sideways, and its temporal region is sandwiched by the hanger, the head rotates unexpectedly. This phenomenon is called “Hanger Reflex”. Although it is one of the simple methods for producing pseudo-force sensation, the position was limited to head. We discovered that a wrist or waist equipped with the bigger size device rotates the arm or the body involuntary. This fact suggests that the principle of Hanger Reflex can be applied to other parts of the body. In this paper, we report development of the device and user test, suggesting that most participants felt the rotational force. The results also suggest possible involvement of shear force to this phenomenon.

1. 中村(拓)，西村，佐藤，梶本：手首と体幹部におけるハンガー反射,第18回一般社団法人情報処理学会シンポジウム インタラクション(2014年 2-3月 東京)，2014[pdf]
2. T. Nakamura, N. Nishimura, M. Sato, H. Kajimoto: Application of Hanger Reflex to wrist and waist. IEEE VR 2014, March 31-April 2, 2014, Minneapolis, United States.[pdf]

手首でのハンガー反射の制御デバイス (A device to control the hanger reflex on the wrist)

Hanger reflex is a strong force illusion that was previously known to occur in the human head. We applied the Hanger Reflex to the wrist and had expected that there would be "sweet spots" for the hanger reflex at the wrist, similar to the properties of the hanger reflex at the head. By measuring the pressure distribution and the rotation angle when the hanger reflex device was attached at the wrist, we found “sweet spots” that can efficiently generate the hanger reflex at the wrist. Based on the pressure distribution obtained, we developed a device to control the generation of the hanger reflex at the wrist. The device reproduces the pressure distribution by pressing on the "sweet spots" for the hanger reflex using four linear actuators, and thus generates the hanger reflex at the wrist. The results of user testing indicated that the device can efficiently present rotational forces.

1. 中村，西村，佐藤，梶本：手首でのハンガー反射発生時の手首圧力分布の計測，日本機械学会ロボティクス・メカトロニクス講演会2014（2014年5月 富山市総合体育館）[pdf].
2. 中村，西村，佐藤，梶本:ハンガー反射を用いた前腕への回旋力提示デバイス,第19回日本バーチャルリアリティ学会大会（2014年9月 名古屋大学東山キャンパス）,2014[pdf]
3. T. Nakamura, N. Nishimura, M. Sato, H. Kajimoto: Development of Wrist-Twisting Haptic Display Using the Hanger Reflex. ACE 2014, November 11-14, 2014, Funchal, Portugal.[pdf]
4. T. Nakamura, N. Nishimura, T. Hachisu, M. Sato, H. Kajimoto: Pressure Threshold of the Hanger Reflex at the Wrist. Asia Haptics 2014, November 18-20, 2014, Tsukuba, Japan. [pdf]

振動重畳によるハンガー反射からの力覚増強現象

The hanger reflex is a phenomenon that accompanies illusory force sensation and involuntary head rotation when the head is fastened with a wire hanger. This phenomenon is also observed on the wrist, and is expected to apply when using small and simple haptic feedback devices. However, issues of slow response and the requirement for large actuators still remain. Here, we discuss the discovery of a new phenomenon: the perceptual force from the hanger reflex is enhanced when a vibration is also presented. If we can control the strength of the perceptual force induced by vibration, a smaller, simpler, and higher response device might be achieved, because a vibrator can be controlled easily. This paper reports details of this phenomenon, and the effect of the frequency and amplitude of the vibration on the strength of the perceptual force. We observed that low frequency (50-100 Hz) vibrations efficiently enhanced the perceptual force, and that participants perceived a stronger perceptual force if the vibration of a greater amplitude was present-ed. These results suggest that the enhancement of the perceptual force is controllable and can be applied to construct a new type of wearable haptic device.

1. 中村(拓)，西村，蜂須，佐藤，梶本： 手首ハンガー反射時の振動提示による力知覚増強，インタラクション2015(第19回一般社団法人情報処理学会シンポジウム) 2015.[pdf]
2. T. Nakamura, N. Nishimura, T. Hachisu, M. Sato, H. Kajimoto, "Controlling the Strength of the Hanger Reflex on the Wrist by Presenting Vibration", IEEE World Haptics Conference 2015, June 22-16, 2015, Chicago, USA.[pdf]
3. T.Nakamura, N.Nishimura, T.Hachisu, M.Sato, V. Yem, H.Kajimoto:Perceptual Force on the Wrist under the Hanger Reflex and Vibration,Euro Haptics 2016, July 4-7, 2016, London, United Kingdom. [pdf]
4. T. Nakamura H. Kajimoto "Enhancement of Perceived Force from the Hanger Reflex on Head and Ankle by Adding Vibration"AsiaHaptics2016, 2016.11.30-12.2, Kashiwanoha, Japan. [pdf]
5. 中村，梶本：ハンガー反射下の手首への振動重畳による力知覚増強現象，日本バーチャルリアリティ学会論文誌，Vol.23，No.1，pp.35-43，2018.