著者
金子 智則 グェン ミンジュン 高畑 智之 松本 潔 下山 勲
出版者
一般社団法人 日本機械学会
雑誌
ロボティクス・メカトロニクス講演会講演概要集
巻号頁・発行日
vol.2013, pp._1A2-C09_1-_1A2-C09_4, 2013

In this paper, we report an approach to measure mechanomyogram (MMG) using a MEMS pressure sensor. The sensor consisted of an open cavity and a micro piezo-resistive cantilever, which was placed at the cavity's opening. The sensor was attached on a subject's forearm to measure the emitted MMG when the subject was exerting forces with his/her arm. In the prototype sensor, the cavity had footprint radius of 5.5 mm and the height of 3 mm. The gap between the cantilever and the surrounding walls was downscaled to 2 μm to enable the sensor to measure low frequency sound pressure with high sensitivity. In experiments, we used an electromyogram recorder, a low frequency microphone and an electronic stethoscope, and based on the results taken with these conventional devices to evaluate our proposed sensor. The experimental results showed that the sensor was able to measure MMG with the maximum S/N ratio of 50.
著者
竹井 裕介 松井 亮 グェン ミン ジュン 高畑 智之 松本 潔 下山 勲
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌. E, センサ・マイクロマシン部門誌 (ISSN:13418939)
巻号頁・発行日
vol.138, no.2, pp.54-58, 2018
被引用文献数
1

<p>We measured flow speed of a moving object in a water with Doppler effect using a MEMS ultrasonic receiver. This measurement is aimed for non-invasive blood pressure measurement. We proposed a wide frequency range receiver to measure both blood flow speed and vessel diameter at the same time in a blood vessel. Our sensor has a piezoresistive cantilever which is put on the boundary between air and liquid in a device. According to this structure, proposed receiver can measure acoustic waves from Hz to MHz order frequency, so that we can obtain blood flow speed (MHz order), and blood pressure change (Hz order) with the same device. On this paper, we measured flow speed ranging from 64.0 to 76.3 mm/s with 5.6 to 19% error.</p>
著者
大森 隆広 碓井 隆 渡部 一雄 グェン ミンジュン 下山 勲
出版者
一般社団法人 日本機械学会
雑誌
IIP情報・知能・精密機器部門講演会講演論文集
巻号頁・発行日
vol.2017, pp.I-4, 2017
被引用文献数
1

Among the many types of sensors for measuring vibration, the AE sensor is designed to measure acoustic emission, i.e., small-amplitude vibration. Most AE sensors use piezoelectric material as transducers. Compared with the piezoelectric sensors, MEMS sensors have beneficial characteristics such as low cost attributable to mass production and smaller size. The SA sensor is a type of MEMS sensor and has broad frequency bandwidth. Exploiting this characteristic, the SA sensor can be used as a multifunctional vibration sensor to measure several frequency ranges conventionally measured by multiple sensors. In this paper, PLB test results measured by SA and AE sensors are evaluated by wavelet transform to investigate the applicability of the SA sensor for AE measurement.