title: Assessment of slow-breathing relaxation technique in acute stressful tasks using a multipurpose non-invasive beat-by-beat cardiovascular monitoring system.
abstract: Recently, several studies revealed that daily slow-breathing exercise lowered blood pressure and increased baroreflex sensitivity. With this interesting finding, we have been contemplating to design a compact breath-controllable device for relaxation to stress reaction during daily living for home as well as ambulatory use, as a final goal, towards reduction of cognitive hemodynamic disorders, hypertension, and acute stress-induced hemodynamic disorders. The present study thereby describes, as a first step, to design a prototype system combining a compact multipurpose non-invasive beat-by-beat cardiovascular monitor developed previously with a wrist-type vibrator to make a respiration rhythm, and to assess an effect of slow-breathing relaxation on the cardiovascular hemodynamics in response to acute stressful conditions. The cardiovascular hemodynamic monitor can measure beat-by-beat systolic (SBP), mean (MBP) and diastolic (DBP) pressure in a finger based on the volume-compensation method, cardiac output (CO) by the electrical admittance method and the other hemodynamic-related parameters (e.g., total peripheral resistance (TPR=MBP/CO), heart rate (HR), respiratory rate, pulse wave velocity, etc.). The wrist-type vibrator can give various breathing rhythms quietly to a subject using a small vibration motor. The stressful tasks loaded to healthy volunteers (3 males, 23-34 yrs.) in the experiments were cold pressor and arithmetic ones as a representative of daily passive and active coping tasks, respectively, under conditions with (respiratory rate of 6 1/min) and without breath control.. The results showed that the slow-breathing technique could have a significant effect on improvement of the hemodynamic changes following the acute stressful tasks, especially in the passive coping task.
authors.affiliation: Kanazawa University Graduate School of Natural Science & Technology, Kanazawa, Japan. nogawa@t.kanazawa-u.ac.jp
authors.forename: Masamichi
authors.initials: M
authors.lastname: Nogawa
authors.forename: Takehiro
authors.initials: T
authors.lastname: Yamakoshi
authors.forename: Akira
authors.initials: A
authors.lastname: Ikarashi
authors.forename: Shinobu
authors.initials: S
authors.lastname: Tanaka
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Yamakoshi
mesh_terms: D000328:Adult; D001676:Biofeedback, Psychology / Q000295:instrumentation* / Q000379:methods; D001945:Breathing Exercises; D004562:Electrocardiography / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000379:methods; D017063:Outcome Assessment, Health Care / Q000379:methods; D012064:Relaxation Therapy / Q000295:instrumentation*; D012129:Respiratory Function Tests / Q000295:instrumentation*; D013312:Stress, Physiological / Q000175:diagnosis / Q000517:prevention & control*; D016896:Treatment Outcome