Sources of breathing pattern variability in the respiratory feedback control loop.

•A computational model of the respiratory control feedback loop exhibits realistic breath-to-breath variations in the amplitude and timing of breathing when random perturbations are applied to both the chemical and neural components of the circuit.•The largest alterations in the variability of breath amplitude and timing are caused by increases in lung resistance and impairments in gas exchange, both common features of pulmonary disease.•Breathing pattern variability may reflect discernible deterministic processes involved in the control of breathing, and may thus have diagnostic potential.