title: Microcomputer servo-controlled bicycle ergometer system for psychophysiological research.
abstract: Steady state exercise is widely used for psychophysiological studies in which a constant heart rate at a predetermined level is desired. We have developed a microcomputer servo-controlled bicycle ergometer system that can be used for administering steady state exercise. Fourteen healthy male subjects, with a wide range of fitness levels (measured by VO2max) were exercised to either a fixed workload (130 watts) or a predetermined heart rate level (servo-heart rate) of 122 bpm (i.e., 65% of maximum calculated heart rate for the sample). Servo-heart rate was implemented using a feedback loop that automatically adjusted workload to compensate for immediate variations in heart rate, resulting in a more consistent heart rate. Heart rate varied from the predetermined value by 17 bpm during fixed workload but only 3 bpm during servo-heart rate (p less than .05). Therefore, by using the microcomputer servo-controlled bicycle ergometer, heart rate was maintained at a predetermined level regardless of the subject's fitness level. VO2max and workload during servo-heart rate were significantly correlated (r = .85, p less than .05). Therefore, the workload necessary to maintain heart rate at a constant level may provide an approximate index of aerobic fitness level.
authors.forename: A R
authors.initials: AR
authors.lastname: Laperriere
authors.forename: D H
authors.initials: DH
authors.lastname: VanDercar
authors.forename: L Y
authors.initials: LY
authors.lastname: Shyu
authors.forename: M F
authors.initials: MF
authors.lastname: Ward
authors.forename: P M
authors.initials: PM
authors.lastname: McCabe
authors.forename: A C
authors.initials: AC
authors.lastname: Perry
authors.forename: P E
authors.initials: PE
authors.lastname: Mosher
authors.forename: N
authors.initials: N
authors.lastname: Schneiderman
mesh_terms: D000328:Adult; D005080:Exercise Test / Q000295:instrumentation*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008838:Microcomputers; D011603:Psychophysiology / Q000295:instrumentation*