Earable TEMPO: A Novel, Hands-Free Input Device that Uses the Movement of the Tongue Measured with a Wearable Ear Sensor

Abstract

In this study, an earphone-type interface named “earable TEMPO” was developed for hands-free operation, wherein the user can control the device by simply pushing the tongue against the roof of the mouth for about one second. This interface can be used to start and stop the music from a portable audio player. The earable TEMPO uses an earphone-type sensor equipped with a light emitting diode (LED) and a phototransistor to optically measure shape variations that occur in the external auditory meatus when the tongue is pressed against the roof of the mouth. To evaluate the operation of the earable TEMPO, experiments were performed on five subjects (men and women aged 22–58) while resting, chewing gum (representing mastication), and walking. The average accuracy was 100% while resting and chewing and 99% while walking. The precision was 100% under all conditions. The average recall value of the five subjects was 92%, 90%, and 48% while resting, masticating, and walking, respectively. All subjects were reliably able to perform the action of pressing the tongue against the roof of the mouth. The measured shape variations in the ear canal were highly reproducible, indicating that this method is suitable for various applications such as controlling a portable audio player.

Earable ZEN: Development of an Earphone-Type Zazen Support Wearable System

“…The earable ZEN developed in this study checks that the signals measured in the ear sensor are contained below the threshold value for the subject in question while they are adopting the special zazen posture and that there are no disturbances in their breathing or posture. Previously, we have seen studies [25–31] that measure the chewing amount and tongue movement using the ear sensor, but these were studies that estimated “what the subject has done” based on changes in the shape of the ear canal. However, the focus of the approach in this study is different to that of previous studies, in which it estimates whether “the subject is not doing anything (is sitting still)”.…”

“…Until now, we have successfully carried out research and development on a hands-free interface that uses measurement results obtained from an ear sensor to measure meal times, number of chews, and tongue exercise [25–31]. The earable ZEN applies this R&D. A characteristic of the earable ZEN is that it can measure disturbances in breathing and posture with just one ear sensor using a simple mechanism.…”

Simultaneous Measurement of Ear Canal Movement, Electromyography of the Masseter Muscle and Occlusal Force for Earphone-Type Occlusal Force Estimation Device Development

“…In addition, we have studied occlusal force measurement as another application that has been used successfully in measurement of mealtimes [4,5,6,7], respiratory rates [8], disturbances in breathing and posture during zazen [9], movements of the tongue [10], and movements of the eyes and intentional blinking [11] while using the same ear sensor from the earable RCC in our previous study. Our next action is thus to conduct research and development of an occlusal force estimation device based on this ear sensor.…”

Earable POCER: Development of a Point-of-Care Ear Sensor for Respiratory Rate Measurement

“…The earable POCER, automatically measure respiration frequency through the attachment of an earphone-sensor (hereafter referred to as an “ear sensor”) to the right ear or left ear of the measured subject and displays the results on a tablet terminal. Thus far, using an ear sensor, we have been successful in researching and developing devices for measuring meal times, a measuring device for the number of chewing times, and hands-free interfaces based on results from measuring tongue activity [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. For this sensor technology for the earable POCER, we applied the ear sensor technology that we developed previously.…”