About Us

Dear Visitor,

This application is part of the COVID19 BreathSim Project. It allows you to simulate ventilating up to four patients using the same ventilator. We hope you find the simulation helpful.

Sincerely,

COVID BreathSim Project Team

About the Multi-Patient Vent Simulator:
This application simulates ventilating multiple patients with one ventilator run in pressure control. It assumes the inspiratory line tubing is split into 1-4 intubated patients. Each of the patients has a valve on the inspiratory line to adjust the flow and the resulting tidal volume. The ventilator has a flow limiter that emulates the possible limited air supply of the ventilator. The lung mechanics of each patient is modeled with a hydraulic RC (resistor-capacitor) circuit. The resistor is nonlinear to capture the turbulence effects of the flow in the tube.

Inputs to the model are:
  • Number of patients to be ventilated (with one ventilator)
  • Pressure control vent settings (inspiratory pressure, PEEP, respiratory rate, I:E ratio)
  • Ventilator flow limiter (% closed)
  • Patient air flow valve (% closed)
  • Endotracheal tube (ETT) size (diameter, length)
  • Patient lung compliance (from very stiff to very compliant)
Note: Volume control ventilation (VCV) of multiple patients using the same ventilator may result in insufficient air supply to one or more patients since the amount of air is shared among them. Drawbacks of VCV for connected patients are also shown here: AARC Guidance on Multiple Patients.
About the Task Force:
This task force is the brainchild of Drs. Julian Goldman and Sandy Weininger. The goal is to simulate potentially safe and harmful scenarios of ventilating multiple patients using the same ventilator. Thanks to Mathworks, Inc. for providing us with Matlab and Simulink licenses used during development of the mathematical model. The COVID Breath Sim Project has made this tool available to others so that anyone can simulate these scenarios. The task force comprises academic, clinical, industrial, and governmental institutions:
  • Julian Goldman, MD, MGH, Harvard Medical School
  • Sandy Weininger, PhD, FDA, HHS
  • Dave Hoadley, PhD, Ravili Kamthamraju, Kirthi Devleker, Mathworks
  • James Philip, Dave Arney, Harvard Medical School
  • Bradford Smith, PhD, University of Colorado
  • Jeff Webb, Rachel Clipp, PhD, Philip Asare, PhD, Kitware
  • Bahram Parvinian, Lighthouse Consulting Group LLC
  • Michael Jaffe, PhD, Cardiovascular Consulting LLC
  • Nicolas Chbat, PhD, Quadrus Medical Technologies
  • Download-Full list of members
Contact Us
For more information about this simulation model, please email Dr. Chbat at chbat@quadrusmedical.com.

Please cite this project in any published, or publicly disseminated, work as follows:

Multi-Patient Vent Sim, A Simulator For Ventilating Multiple Patients.

N. Chbat, C. Chiofolo, A. Moshova, M. Qureshi (2020), www.quadrusmedical.com/ventapp.php