Modelling of the baroreflex-feedback mechanism with time-delay

Area of Science:

• Physiology
• Biomedical Engineering
• Control Systems

Background:

• The cardiovascular system's regulation is complex, involving feedback mechanisms like the baroreflex.
• Understanding the impact of time-delays in physiological systems is crucial for accurate modeling.
• Previous models may not fully capture the non-linear dynamics and time-delay effects of the baroreflex.

Purpose of the Study:

• To develop a direct model of the non-linear baroreflex-feedback mechanism, incorporating time-delay.
• To analyze the stability of the cardiovascular model under varying time-delay conditions.
• To investigate the potential role of time-delay in physiological phenomena like Mayer waves.

Main Methods:

• Development of a non-linear baroreflex-feedback model based on physiological theory and empirical data.
• Evaluation of the feedback model using a non-pulsatile Windkessel model of the cardiovascular system.
• Stability analysis of the integrated model and investigation of time-delay effects, including ergometer bicycle test data.

Main Results:

• The baroreflex model with time-delay was successfully developed and evaluated.
• Time-delay was shown to be a potential cause of oscillations and stability switches in the cardiovascular model.
• The location of stability switches was found to be sensitive to model parameter values.

Conclusions:

• Time-delay in the baroreflex mechanism can significantly influence cardiovascular system stability and dynamics.
• The model provides a framework for understanding oscillations such as Mayer waves.
• Further experimental validation is suggested to confirm the role of time-delay in specific physiological phenomena.