A Portable Servoregulation Controller to Automate CO₂ Removal in Artificial Lungs

Area of Science:

• Biomedical Engineering
• Respiratory Support Technology
• Control Systems

Background:

• Current artificial lung (AL) systems lack adaptability to patient metabolic demands, limiting comfort and rehabilitation.
• Automatic adjustment of carbon dioxide (CO2) removal is crucial for effective AL therapy.
• Existing AL systems cannot dynamically respond to changes in patient activity or disease status.

Purpose of the Study:

• To develop and evaluate a portable servoregulation controller for AL systems.
• To enable automatic, real-time modulation of CO2 removal based on patient metabolic needs.
• To advance the development of ambulatory artificial lung systems.

Main Methods:

• A proportional-integral-derivative (PID) based closed-loop feedback control system was implemented.
• Sweep gas flow was modulated to maintain a target exhaust gas CO2 partial pressure (tEGCO2).
• Gas-side sensing, portable packaging, and integrated moisture removal were utilized.

Main Results:

• The controller rapidly adjusted sweep gas flow (<2 min) to meet target tEGCO2 levels despite changes in blood CO2.
• CO2 removal demonstrated a strong correlation with blood flow rate and blood CO2 levels.
• The system operated continuously for up to 5 days in vitro, showing stability and reliability.

Conclusions:

• The developed controller represents a significant advancement for artificial lung systems.
• This technology facilitates the creation of ambulatory AL systems that adapt to patient needs.
• The system's ability to modulate CO2 removal supports enhanced patient comfort, activity, and rehabilitation.