A Multi-armed Unfurling Actuator for Airway Lumen Measurement

Area of Science:

• Biomedical Engineering
• Medical Devices
• 3D Printing Applications

Background:

• Accurate measurement of central airway narrowing is crucial for clinical decision-making.
• Current methods for assessing tracheal stenosis often rely on subjective assessments.
• Objective, intraoperative tools are needed for precise lumen area determination.

Purpose of the Study:

• To develop and validate a novel compliant mechanism-based unfurling actuator for measuring tracheal lumen diameter and area.
• To assess the accuracy and stability of the developed device for intraoperative use.
• To provide a tool for objective grading of tracheal stenosis.

Main Methods:

• A 3D-printed, compliant mechanism-based unfurling actuator integrated with a motorized encoder was designed.
• The device's four flexible arms coil within a casing and unfurl radially to measure lumen patency.
• Rotary encoder output was correlated with arm movement to estimate lumen dimensions; stability was assessed using process control charts.

Main Results:

• The device demonstrated high measurement stability, with nearly 100% of data falling within control limits over ten iterations.
• One-way ANOVA showed no significant differences between device measurements and direct measurements (vernier caliper, ImageJ) for diameter (p=0.974) and area (p=0.975).
• The four-arm design effectively measures varying grades of circumferential tracheal stenosis.

Conclusions:

• The developed 3D-printed unfurling actuator is a viable tool for objective, intraoperative measurement of tracheal lumen dimensions.
• This device can aid in accurate grading of tracheal stenosis, improving decision-making for interventions like intubation.
• The technology offers a promising solution for enhancing the assessment of central airway narrowing.