title: Detection of Site-Specific Blood Flow Variation in Humans during Running by a Wearable Laser Doppler Flowmeter.
abstract: Wearable wireless physiological sensors are helpful for monitoring and maintaining human health. Blood flow contains abundant physiological information but it is hard to measure blood flow during exercise using conventional blood flowmeters because of their size, weight, and use of optic fibers. To resolve these disadvantages, we previously developed a micro integrated laser Doppler blood flowmeter using microelectromechanical systems technology. This micro blood flowmeter is wearable and capable of stable measurement signals even during movement. Therefore, we attempted to measure skin blood flow at the forehead, fingertip, and earlobe of seven young men while running as a pilot experiment to extend the utility of the micro blood flowmeter. We measured blood flow in each subject at velocities of 6, 8, and 10 km/h. We succeeded in obtaining stable measurements of blood flow, with few motion artifacts, using the micro blood flowmeter, and the pulse wave signal and motion artifacts were clearly separated by conducting frequency analysis. Furthermore, the results showed that the extent of the changes in blood flow depended on the intensity of exercise as well as previous work with an ergometer. Thus, we demonstrated the capability of this wearable blood flow sensor for measurement during exercise.
authors.affiliation: Advanced Manufacturing Research Institute, National Institute of Advanced Industrial Science and Technology, 807-1 Shuku-machi, Tosu, Saga 841-0052, Japan. wataru.iwasaki@aist.go.jp.
authors.forename: Wataru
authors.initials: W
authors.lastname: Iwasaki
authors.affiliation: Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan. nogami@mech.kyushu-u.ac.jp.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Nogami
authors.affiliation: Department of Dermatology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 819-8582, Japan. takeuchs@dermatol.med.kyushu-u.ac.jp.|Department of Dermatology, Federation of National Public Service Personnel Mutual Aid Associations, Hamanomachi Hospital, 3-3-1 Nagahama, Chuo-ku, Fukuoka 810-8539, Japan. takeuchs@dermatol.med.kyushu-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takeuchi
authors.affiliation: Department of Dermatology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 819-8582, Japan. furue@dermatol.med.kyushu-u.ac.jp.
authors.forename: Masutaka
authors.initials: M
authors.lastname: Furue
authors.affiliation: Department of Precision Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan. eiji@su.t.u-tokyo.ac.jp.
authors.forename: Eiji
authors.initials: E
authors.lastname: Higurashi
authors.affiliation: Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan. sawada@mech.kyushu-u.ac.jp.
authors.forename: Renshi
authors.initials: R
authors.lastname: Sawada
mesh_terms: D000328:Adult; D045268:Flowmeters; D006439:Hemodynamics; D006801:Humans; D017078:Laser-Doppler Flowmetry / Q000295:instrumentation* / Q000379:methods; D008297:Male; D055617:Micro-Electrical-Mechanical Systems; D063731:Mobile Applications; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D012039:Regional Blood Flow / Q000502:physiology*; D012212:Rheology; D012420:Running / Q000502:physiology*; D013686:Telemetry / Q000295:instrumentation; D055815:Young Adult
keywords: MEMS; blood flow; exercise; laser Doppler; wearable sensor