[Purpose] We aimed to determine the effects of ventilation feedback using electrical
stimulation on ventilation pattern during exercise in patients with chronic obstructive
pulmonary disease (COPD), and develop new rehabilitation methods. [Subjects] This
randomized double-blind placebo-controlled trial included 24 patients with COPD. [Methods]
Phasic electrical stimulation during expiration (PESE) or a placebo was given to all the
cases. Minute ventilation (VE), tidal volume (TV), respiratory rate (RR), expiratory time
(Te), total respiratory time (Ttot), dead-space gas volume to tidal gas volume (VD/VT),
oxygen uptake (VO2), carbon dioxide output (VCO2), Borg scale
(Borg), and percutaneous oxygen saturation (SpO2) during rest and exercise were
assessed. [Results] The placebo group showed no obvious change in ventilation measurements
at rest or during exercise. However, in the PESE group, TV, Te, and Ttot significantly
increased, while RR and VD/VT significantly decreased during exercise compared with the
baseline measurements. Borg scores, SpO2, VO2, or VCO2
did not differ significantly. [Conclusion] PESE improves the ventilation pattern during
rest and exercise. Furthermore, PESE does not increase VO2, which may indicate
an increased workload. Biofeedback may contribute to PESE effects. Stimulation applied
during expiration may evoke sensations increasing prolonged expiration awareness,
facilitating prolongation.