# Hardware-in-Loop Modules for Testing Automated Ventilator Controllers
## 5 Conclusions  
Automated ventilation control has the potential to simplify critical care in civilian and military environments. However, control systems require extensive testing for proper tuning, which can be cost-ineffective when relying solely on animal studies for troubleshooting. Although in-silico models have become exceedingly advanced in recent years, they still require large and highly specialized data to be properly tuned and are not able to operate with physical devices, leaving an important gap in our ability to determine the performance of a controller. Systems that include hardware control still often lack a direct link between the real-world outputs of the ventilator and the feedback signals that serve as the inputs to the ventilator controller. Instead, the HIL testbed presented in this work allows for physical hardware debugging in a high-throughput manner for oxygen and mechanical ventilation controller logics. The OxyVent and MechVent modules were able to reproduce the physiological feedback signals of interest within ranges that have been observed in in-vivo studies. Both modules were also directly responsive to the outputs of a commercial ventilator when controlled by a simplistic control scheme. Using this platform, more extensive testing can be performed prior to animal experiments, allowing for more refined controllers to be evaluated and drastically streamlining the translation process for these life-saving medical devices. As a result, closed-loop ventilator development can be accelerated, thus lowering the skill threshold and improving ventilator management in future critical care and combat casualty care situations. Conceptualization, E.J.S. and D.B. ; methodology, D.B., B.A., D.O. and I.M. ; software, B.A. and D.O. ; validation, D.B., B.A. and D.O. ; formal analysis, D.B., B.A., D.O., J.M.G., S.I.H.T. and E.J.S. ; investigation, E.J.S. ; resources, E.J.S. ; data curation, D.B., B.A. and D.O. ; writing--original draft preparation, D.B., B.A., D.O., I.M., J.M.G., S.I.H.T. and E.J.S. ; writing--review and editing, D.B., B.A., D.O., I.M., J.M.G., S.I.H.T. and E.J.S. ; visualization, B.A., I.M., J.M.G., S.I.H.T. and E.J.S. ; supervision, E.J.S. ; project administration, E.J.S. ; funding acquisition, E.J.S. All authors have read and agreed to the published version of the manuscript. This work was funded by the U.S. Army Medical Research and Development Command (CO230029). This project was supported in part by an appointment to the Science Education Programs at National Institutes of Health (NIH), administered by ORAU through the U.S. Department of Energy Oak Ridge Institute for Science and Education (B.A., D.O., I.M.). Not applicable. The datasets presented in this article are not readily available because they have been collected and maintained in a government-controlled database that is located at the US Army Institute of Surgical Research. As such, these data can be made available through the development of a Cooperative Research & Development Agreement (CRADA) with the corresponding author. Requests to access the datasets should be directed to [PERSON], [EMAIL_ADDRESS]. The authors would like to acknowledge [PERSON] for his assistance with the development of the testing procedures used to evaluate the hardware-in-loop test platform. The authors would also like to acknowledge ongoing collaboration with Thornhill Medical and their MOVES(r) SLCT(tm) ventilator platform. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results. The views expressed in this article are those of the authors and do not reflect the official policy or position of the U.S. Army Medical Department, Department of the Army, DoD, or the U.S. Government. The following abbreviations are used in this manuscript: