Development and evaluation of an automated breathing-synchronized chest wall vibration stimulation system

[Purpose] Vibratory stimulation of the upper intercostal region enhances inspiratory movement, whereas stimulation of the lower intercostal region enhances expiratory movement and ventilation. Previous vibration stimulation devices for intercostal muscles required manual stimulation, causing a time lag between breathing and vibration stimulation. The purpose of this experiment was to compare the effects of an automatic vibration stimulation system with manual vibration stimulation in a group of individuals and to verify whether there was an increase in upper and lower chest wall displacement and respiratory flow. [Participants and Methods] Twenty healthy adults were divided into two groups, as follows: an automatic vibration stimulation group using a chest wall vibration stimulation system and a manual vibration stimulation group. Vibration stimulation was applied to the second intercostal space on both sides during inspiration, and to the seventh intercostal space on both sides during expiration. [Results] The vibration stimulation system group showed significantly higher synchronization rates during inspiration and expiration than the manual vibration stimulation group, and there was a significant increase in chest wall displacement and respiratory flow during inspiration and expiration. [Conclusion] The chest wall vibration stimulation system can effectively provide vibration stimulation to the intercostal muscles in synchrony with breathing.