[Paper Review] Monitoring and Control System Development and Experimental Validation for a Novel Extrapulmonary Respiratory Support Setup

Mahsa Doosthosseini, Kevin Aroom+10 more|arXiv (Cornell University)|Jul 4, 2021

Mechanical Circulatory Support Devices26 references4 citations

TL;DR

This paper presents a novel extrapulmonary respiratory support system that uses oxygenated perfluorocarbon (PFC) perfusion in the peritoneal cavity to support gas exchange in patients with respiratory failure. The system enables real-time monitoring and control of flowrate, pressure, temperature, and oxygenation, with successful experimental validation in swine demonstrating stable perfusion and data collection for physiological response analysis.

ABSTRACT

This paper presents a novel mechatronic setup intended for providing respiratory support to patients suffering from pulmonary failure. The setup relies upon the circulation of an oxygenated perfluorocarbon (PFC) through the abdominal cavity. Such circulation provides a potential pathway for the transport of oxygen to the bloodstream. However, the viability of this technology for $CO_2$ clearance has not been established. Moreover, there is a lack of experimental data enabling the modeling and identification of the underlying dynamics of this technology. To address these gaps, we develop a flexible experimental perfusion setup capable of monitoring and controlling key variables such as perfusate flowrate, temperature, pressure, and oxygenation. The paper (i) briefly summarizes the design of this setup; (ii) highlights the degree to which its data acquisition system enables the collection and cross-correlation of both perfusion-related and physiological variables; and (iii) discusses the development of flow, pressure, and temperature control algorithms for the setup. Experiments with large animals (swine) show that the setup is capable of successfully controlling the perfusion process, as well as gathering extensive data to support subsequent modeling and identification studies.

Motivation & Objective

• To develop a flexible, closed-loop monitoring and control system for a novel extrapulmonary respiratory support setup using perfluorocarbon (PFC) perfusion in the abdominal cavity.
• To address the lack of experimental data on PFC perfusion dynamics and its efficacy in CO2 clearance and oxygenation.
• To enable simultaneous acquisition of perfusion variables and physiological responses (e.g., pulse oximetry, end-tidal CO2) for modeling and validation.
• To validate the system’s functionality in large animal (swine) experiments under controlled conditions.
• To support future research on the minimum viable complexity of such systems for clinical gas exchange.

Proposed method

• Design and implementation of a mechatronic perfusion circuit with integrated sensors for flowrate, pressure, temperature, and PFC oxygenation.
• Development of feedback control algorithms for maintaining target perfusate flowrate, pressure, and temperature during animal experiments.
• Integration of a data acquisition system capable of cross-correlating perfusion parameters with physiological metrics such as pulse oximetry and end-tidal CO2.
• Use of a capnograph to infer inspired and end-tidal CO2 concentrations from tracheal gas measurements during ventilation changes.
• Employment of active suction to rapidly reduce peritoneal cavity pressure after perfusion cycles.
• Conducting four large animal (swine) experiments to evaluate system stability, control performance, and data quality.

Experimental results

Research questions

• RQ1 Can a closed-loop monitoring and control system effectively regulate perfusate flowrate, pressure, and temperature during peritoneal PFC perfusion in large animals?
• RQ2 To what extent can the system collect synchronized data on perfusion variables and physiological responses (e.g., pulse oximetry, ETCO2) for subsequent modeling?
• RQ3 What is the system’s ability to maintain stable cavity pressure within safe limits during perfusion and retrieval phases?
• RQ4 How does PFC perfusion influence animal oxygenation and CO2 clearance, as indicated by changes in pulse oximetry and end-tidal CO2?
• RQ5 What level of system complexity is necessary to achieve reliable and measurable gas exchange via peritoneal perfusion?

Key findings

• The monitoring and control system successfully maintained perfusate flowrate, pressure, and temperature within desired setpoints during all four swine experiments.
• Peritoneal cavity pressure remained within safe limits, with brief deviations above setpoint followed by rapid flowrate reduction and active suction to restore baseline.
• The system enabled continuous, synchronized measurement of perfusion parameters and physiological variables such as pulse oximetry and end-tidal CO2 (ETCO2).
• A decline in pulse oximetry was observed during induced hypoxia, followed by partial recovery, suggesting potential contributions from PFC perfusion and physiological recovery.
• Improvements in end-tidal CO2 concentration were observed during hypercarbia induction, indicating possible CO2 removal via PFC perfusion, though contributions from physiological mechanisms could not be fully isolated.
• The experimental setup demonstrated robust data acquisition and control performance, providing a foundation for future modeling and identification of PFC perfusion dynamics.