Dynamic Ventilatory circuit divider: Safer way to multiply the number of available ventilators

Mazhar, Rashid; Chowdhury, Muhammad E. H.; Ramzee, Ahmed Faidh; Raza, Tasleem; Surgery, Abdulaziz Ahmed Al-Hashemi Pulmonology-Thoracic; Hospital, Hamad General; Doha,; Qatar,; Engineering, Department of Electrical; University, Qatar

Background: Recent pandemic has brought a sudden surge in the requirement of mechanical ventilators all over the world. In this backdrop, there is wide interest in looking for ways to support multiple patients from a single ventilator. Various solutions, based upon simple mechanical division of the ventilator tubings are described. However, recently warnings have been issued by multiple international professional societies against these plumbing solutions as it can seriously harm the patients. Methods: We have bifurcated the inspiratory and expiratory conduits from a single ventilator with addition of one way valves, pressure and flow sensors along with volume and PEEP control. A purpose-built software and a low-cost microcontroller based control system integrates and displays the data in the familiar ventilatory graphic and numerical format onto a generic screen. The system is calibrated with simulated lungs with varying compliance. In addition to the standard microbial, heat and moisture exchanger filters we design to add UV-C lights at 254-260 nanometre wavelength in the expiratory channel for its virucidal effect. Results: The dynamic ventilatory divider system is capable of providing and controlling individual flow, tidal volume (TV) and Positive End-expiratory pressure (PEEP) for individual patients. Furthermore, it would also display the ventilatory parameters of both the patients, on a single split screen, in a familiar format. FiO2 and rate are still controlled by the mother ventilator. Conclusions: The prototype system has a potential to provide safe ventilation to at least two individuals from a single ventilator, while maintaining the unique requirements of each patient.