Real-time chest-wall-motion tracking by a single optical fibre grating: a prospective method for ventilator...

Area of Science:

• Biomedical Engineering
• Respiratory Physiology
• Sensor Technology

Background:

• Non-invasive mechanical ventilation (NIV) commonly uses facemasks, which are prone to air leaks.
• These leaks cause inaccurate feedback from pneumatic sensors, leading to patient-ventilator asynchrony.
• Asynchrony can result in negative clinical consequences for patients requiring respiratory support.

Purpose of the Study:

• To evaluate an optical fibre-grating sensor for measuring chest-wall motion.
• To test its efficacy as a more accurate non-invasive ventilator triggering mechanism.
• To improve upon existing pneumatic triggering systems affected by air leaks.

Main Methods:

• A long-period fibre-grating sensor was developed to measure chest-wall curvature.
• The sensor was externally applied to the rib-cage of 34 healthy volunteers.
• Wavelet transform processing was used to remove heartbeat signals before data analysis.

Main Results:

• The fibre-grating sensor consistently provided an advance of (230 ± 100) ms compared to standard pneumatic signals.
• Heart activity removal significantly improved sensor accuracy, reducing error from 60 ml to 0.3 ml.
• The sensor demonstrated robustness against air leaks inherent in facemask interfaces.

Conclusions:

• Chest-wall motion measurement via fibre-grating sensors offers a more reliable non-invasive ventilator triggering method.
• This technique is impervious to air leaks, non-invasive, low-cost, and easy to implement.
• The sensor shows promise for improving ventilation in both clinical and homecare settings.