Open-source device to apply controlled positive or negative airway pressure for vocal training

Voice generation and modulation depend both on the geometry and the passive mechanical properties of the soft phonation anatomic structures (mainly the vocal folds), and on the active contribution of upper airway muscles involved in phonation. Treatment for voice dysfunctions includes performing rehabilitation exercises when the phonation system is mechanically loaded to positively modify its function. Here we present a novel device to apply either positive or negative airway pressure to facilitate voice recovery. The device is based on the ability of a type of blower specially designed to generate a pressure drop caused by their blades rotation. Application of constant positive/negative pressure at the patient’s airway through a nasobuccal mask is achieved by Arduino-controlling the blower speed from the pressure signal measured by a sensor. A set of 3-way electrovalves configurates the blower as a positive or negative pressure generator (ranging from -50 cmH2O to +50 cmH2O). The device feasibility was assessed in 10 voluntary subjects, who reported easy use and subjective improvements in perceived vocal comfort. As the device is easy to build, low-cost, small and portable, it is potentially applicable for voice rehabilitation both at healthcare facilities and at the patient’s home.