Accuracy of Real-Time Data Provided by Mechanical Insufflation-Exsufflation Devices

Area of Science:

• Respiratory Mechanics and Therapy
• Medical Device Technology

Background:

• Mechanical insufflation-exsufflation (MI-E) is vital for patients with impaired cough, particularly those with neuromuscular diseases.
• Accurate real-time monitoring of peak expiratory flow (PEF) and inspiratory volume during MI-E therapy remains a challenge despite technological advancements.

Purpose of the Study:

• To evaluate the accuracy of PEF and inspiratory volume monitoring across different MI-E devices.
• To identify factors contributing to monitoring errors in MI-E devices under various clinical conditions and settings.

Main Methods:

• A bench study utilized a mechanical lung connected to three MI-E devices (EOVE-70, E-70, Comfort Cough II).
• Evaluated PEF and inspiratory volume accuracy under low and normal lung compliance conditions with six different MI-E pressure settings.
• Compared device-displayed values against measurements from a pneumotachograph, assessing flow bias.

Main Results:

• All tested MI-E devices systematically underestimated PEF and inspiratory volume.
• Device A showed the smallest PEF underestimation error (-7.4%), while devices B and C had larger errors (-26.5% and -29.9%).
• Device B demonstrated the least inspiratory volume underestimation error (-15.1%), with device A showing a larger error (-26.9%). Device type, high-pressure settings, and lung compliance significantly impacted estimation errors.

Conclusions:

• Consistent underestimation of PEF and inspiratory volume was observed across all evaluated MI-E devices.
• Improving the accuracy of monitoring parameters in MI-E devices is essential for optimizing therapy guidance and ensuring patient safety.