Matsumoto Keiji, Temiz Yuksel, Taghavi Hamidreza, Cornelius Elrick L, Mori Hiroyuki, Michel Bruno
Annu Int Conf IEEE Eng Med Biol Soc. 2019 Jul;2019:7049-7055. doi: 10.1109/EMBC.2019.8856821.
Heat-stroke has become a serious problem in Japan, especially for elderly citizens. For the early detection and prevention of heat-stroke, a wearable health monitor for in-ear use is developed which is subsequently called "Hearable". It aims to measure three vital parameters: Core body temperature, sweat rate and sweat or interstitial sodium ion (Na) concentration. The eardrum is a good place to measure the core body temperature, because it is close to the carotid artery and the brain. We develop a hearable prototype and it consists of an audio earbud, a sensor earbud and a micro controller. Concerning the sensor earbud, a present prototype includes an eardrum (tympanic) temperature sensor and a sweat rate sensor and we implement two variants. Variant-1 focuses on the sweat rate sensing using a humidity & temperature sensor located close to the eardrum and Variant-2 focuses on the eardrum temperature sensing using an IR temperature sensor. Concerning the sweat rate sensing, unlike conventional sweat sensors, our prototypes do not include an air flow pump, which is typically used to determine the air flow rate. We demonstrate the accuracy of sweat rate sensing based on the air flow rate measured from the evaporation of defined amount of water. We use Variant-2 to demonstrate the monitoring of the eardrum temperature and the sweat rate to differentiate a calm state and jogging.
中暑在日本已成为一个严重问题，尤其是对老年人而言。为了早期发现和预防中暑，研发了一种用于入耳的可穿戴健康监测器，随后被称为“可听设备”。它旨在测量三个重要参数：核心体温、出汗率以及汗液或组织间液钠离子（Na）浓度。鼓膜是测量核心体温的理想部位，因为它靠近颈动脉和大脑。我们开发了一个可听设备原型，它由一个音频耳塞、一个传感器耳塞和一个微控制器组成。关于传感器耳塞，当前的原型包括一个鼓膜温度传感器和一个出汗率传感器，并且我们实现了两种变体。变体1专注于使用位于鼓膜附近的湿度和温度传感器来感知出汗率，变体2专注于使用红外温度传感器来感知鼓膜温度。关于出汗率传感，与传统的汗液传感器不同，我们的原型不包括通常用于确定空气流速的气流泵。我们基于从一定量水的蒸发所测量的空气流速来证明出汗率传感的准确性。我们使用变体2来演示对鼓膜温度和出汗率的监测，以区分平静状态和慢跑状态。
