Heart rate regulation during cycle-ergometer exercise via event-driven biofeedback

Abstract

This paper is devoted to the problem of regulating the heart rate (HR) response along a predetermined reference profile, for cycle-ergometer exercises designed for training or cardio-respiratory rehabilitation. The controller designed in this study is a non-conventional, non-modelbased, proportional, integral and derivative (PID) controller. The PID controller commands can be transmitted as biofeedback auditory commands, which can be heard and interpreted by the exercising subject to increase or reduce exercise intensity. However, in such a case, for the purposes of effectively communicating to the exercising subject a change in the required exercise intensity, the timing of this feedback signal relative to the position of the pedals becomes critical. A feedback signal delivered when the pedals are not in a suitable position to efficiently exert force may be ineffective and this may, in turn, lead to the cognitive disengagement of the user from the feedback controller. This note examines a novel form of control system which has been expressly designed for this project. The system is called an "actuatorbased event-driven control system". The proposed control system was experimentally verified using twenty four healthy male subjects who were randomly divided into two separate groups, along with cross validation scheme. A statistical analysis was employed to test the generalisation of the PID tunes, derived based on the average transfer functions of the two groups, and it revealed that there were no significant differences between the mean values of root-meansquare of the tracking error of two groups [3.9 vs. 3.7 bpm,

Heart Rate Variability Control Using a Biofeedback and Wearable System

“…Referring to automatic control, some controller applications based on fuzzy logic have been applied in biofeedback, such as [ 16 , 44 , 45 , 46 ]. In addition, other types of applications associated with automatic control are associated with the control of sleep apnea and physical behavior in sports, among other related areas, controllers have been applied in continuous and discrete time [ 47 , 48 , 49 ].…”

Identification and comparison of heart-rate dynamics during cycle ergometer and treadmill exercise

“…In contrast, when a model of HR dynamics is required for feedback control synthesis, the prevalent approach is to linearise the system by considering small-signal deviations around a nominal input-output operating point [12, 13]. Such models have been used for model-based design of feedback controllers that automatically adjust the manipulated variable (e.g.…”

Robust control of heart rate for cycle ergometer exercise

“…HR is a quantitative variable that can be easily measured, and several approaches have been investigated for automatic control of HR during both treadmill and cycle ergometer exercise ([3–5] and [6–8], respectively). These feedback systems facilitate tracking of arbitrary HR profiles by automatically and continuously adjusting a manipulated variable, which for treadmills can be speed or slope, or both, and which for cycling is usually work rate.…”

“…Since cycle ergometers provide a stable-seated position, they are the preferred modality for exercise testing and prescription in cardiac rehabilitation; HR controllers have long been investigated in this context [6, 9, 10], but also, subsequently, for healthy persons [7, 8, 11].…”

“…A recent study of HR control during cycle ergometry combined an LTI proportional-integral-derivative (PID) controller with an auditory biofeedback signal [8]. Despite the human-in-the-loop nature of this approach, quite accurate tracking was achieved with mean RMSE on the range 3.7 bpm to 5.0 bpm (various experiments with 24 healthy male participants).…”