title: Wrist Pulse Rate Monitor Using Self-Injection-Locked Radar Technology.
abstract: To achieve sensitivity, comfort, and durability in vital sign monitoring, this study explores the use of radar technologies in wearable devices. The study first detected the respiratory rates and heart rates of a subject at a one-meter distance using a self-injection-locked (SIL) radar and a conventional continuous-wave (CW) radar to compare the sensitivity versus power consumption between the two radars. Then, a pulse rate monitor was constructed based on a bistatic SIL radar architecture. This monitor uses an active antenna that is composed of a SIL oscillator (SILO) and a patch antenna. When attached to a band worn on the subject's wrist, the active antenna can monitor the pulse on the subject's wrist by modulating the SILO with the associated Doppler signal. Subsequently, the SILO's output signal is received and demodulated by a remote frequency discriminator to obtain the pulse rate information.
authors: Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung 80424, Taiwan. fkw@mail.ee.nsysu.edu.tw.
authors: Fu-Kang
authors: FK
authors: Wang
authors: Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung 80424, Taiwan. p940281@gmail.com.
authors: Mu-Cyun
authors: MC
authors: Tang
authors: Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung 80424, Taiwan. scps312@gmail.com.
authors: Sheng-Chao
authors: SC
authors: Su
authors: Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung 80424, Taiwan. jason@ee.nsysu.edu.tw.
authors: Tzyy-Sheng
authors: TS
authors: Horng
mesh_terms: D006339:Heart Rate; D006801:Humans; D008991:Monitoring, Physiologic / Q000379:methods*; D011674:Pulse; D011825:Radar; D055986:Vital Signs; D014953:Wrist
keywords: bistatic radar architecture; continuous-wave (CW) radar; self-injection-locked (SIL) radar; wrist pulse rate monitor