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

Abstract

Meditation has been included in mental health care and the treatment of hypertension and pain. Zazen is a method of entering the meditative state. We have carried out R&D on a wearable system (earable ZEN) that casually and simply allows the subject to perform zazen without going to a temple or even having a zazen monitor present. In zazen, it is important to prepare one's breathing and posture. The earable ZEN is comprised of an earphone-type sensor (ear sensor) for measuring the breathing and posture of the user, a miniature actuator (neck belt) for communicating disturbances in the breathing and posture of the user, and a microcomputer. In an evaluation experiment, disturbance in breathing was simulated as “deep mouth breathing” and disturbance in posture was simulated as “nodding”. The average accuracy value for seven healthy subjects wearing the earable ZEN was 99.9% for mouth breathing and 100% for nodding. In the same way, the average precision value was 98.7% for mouth breathing and 100% for nodding, with an average recall value of 97.1% for mouth breathing and 100% for nodding. None of the subjects considered the ear sensor and neck belt to be an obstacle to zazen.

Health-Related Indicators Measured Using Earable Devices: Systematic Review

“…Reported uses of earable devices were diet-related activity monitoring (9/51, 18% of the articles) [ 19 , 32 - 39 ]; brain status monitoring (7/51, 14% of the articles) [ 40 - 45 , 78 ]; cardiovascular disease (CVD) monitoring (5/51, 10% of the articles) [ 46 - 50 ]; central nervous system (CNS) disease monitoring and diagnosis (5/51, 10% articles) [ 51 - 54 , 79 ]; head injury monitoring (4/51, 8% of the articles) [ 55 - 58 ]; and monitoring of heart status [ 59 - 61 ], respiration [ 20 , 62 ], and sleep disorders [ 63 , 64 ] (7/51, 14% of the articles). Earable devices were used to monitor multiple diseases and health conditions in 16% (8/51) of the studies, namely, brain, cardiac, and respiratory functions [ 65 ]; cardiovascular status, sweating, and motion [ 66 ]; HR and breathing rate [ 67 ]; respiration and posture [ 21 ]; metabolic functions in relation to fever, insomnia, fatigue, and depression [ 22 ]; gait classification [ 68 ]; cardiovascular, metabolic, and mental disorders, including stress and pain response [ 69 ]; and chronic stress, cognitive dysfunctions, depression, and CVD [ 70 ]. In another 12% (6/51) of the studies, earable devices were used to monitor various aspects of health status, namely, thermoregulation [ 71 ], fertility [ 72 ], heat stress [ 73 ], tongue movements [ 18 ], facial expressions [ 74 ], and physical activity [ 75 ].…”

“…EEG was used for monitoring in 22% (11/51) of the studies [ 40 , 41 , 43 - 45 , 51 - 54 , 63 , 78 ], body movements were monitored in 12% (6/51) of the studies [ 18 - 21 , 33 , 75 ], and body temperature was monitored in 10% (5/51) of the studies [ 22 , 64 , 71 - 73 ]. Photoplethysmography (PPG) was used for monitoring in 8% (4/51) of the studies [ 32 , 48 , 60 , 69 ], acceleration stress was monitored in 8% (4/51) of the studies [ 55 - 58 ], and ECG was used for monitoring in 6% (3/51) of the studies [ 49 , 50 , 59 ].…”

“…Wearable devices that are worn around the ear are named “earable” or “hearable.” Kurosawa et al [ 17 ] first proposed the term “earable” in 2017 to refer to a novel earphone-type wearable sensor. On the basis of this prototype, they developed several earable models for various uses [ 18 - 21 ]. Ota et al [ 22 ] expanded the earable device concept, defining such a device as a “wearable electronic designed to be worn around the ear.” Hunn [ 23 ] coined the term “hearable” in 2014 to refer to a device “that fits in or on an ear that contains a wireless link, whether that’s for audio, or remote control of audio augmentation.” The potential use of hearable devices for the measurement of vital signs has been reviewed extensively [ 3 , 24 ].…”

Earable Ω (OMEGA): A Novel Clenching Interface Using Ear Canal Sensing for Human Metacarpophalangeal Joint Control by Functional Electrical Stimulation

“…Therefore, we propose an earphone-type clenching sensor interface for FES, unlike existing ones that require the placement of sensors around the mouth. We have developed an earphone-type ear canal movement sensor [ 35 , 36 , 37 , 38 , 39 , 40 , 41 ] and showed its application in measuring clenching occlusal force [ 42 , 43 , 44 ]. We use this earphone-type ear canal movement sensor, an earphone-type occlusal measurement device (earable (OMEGA)), for an FES interface to make the mouth free from sensors by measuring the clenching motion in the ear canal.…”

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.…”