Real-time Monitoring the Resistance and Compliance of Airway in Noninvasive Positive Pressure Support Ventilation

The noninvasive mechanical ventilation has been widespread adoption in supporting the breath of respiratory patient. But it faces a challenge in effectively monitoring resistance (R) and compliance (C) in the airway during ventilation. In this paper, a technical approach was proposed to real-time noninvasive monitor the values of R and C (RTNM-RC) for the subject undergoing noninvasive positive pressure support ventilation (Ni-PPSV). In the end of expiration, a specially abrupt negative pressure pulse (ΔP) is superimposed onto the expiratory positive airway pressure (EPAP) to generate a corresponding airflow (ΔQ) and volume change (ΔV). Leveraging the ΔP, ΔQ and ΔV, the values of R and C in the airway can be calculated out. The methodology of RTNM-RC was programmed for developing a function prototype of Ni-PPSV respirator. With the function prototype, the active servo lung ASL5000 and a laptop, an experimental platform was designed. Sequentially configuring the ASL5000 to simulate diverse respiratory profiles, a series of experiments were conducted to test the RTNM-RC. The experimental outcomes illustrate the calculated values of R and C are aligning with the preset values in the ASL5000 (relative errors < 10%). The RTNM-RC will be potentially applied in clinics to benefit the respiratory patient with real-time adjusting the treatment strategies during Ni-PPSV based on the values of R and C.