The wide-range ejector flowmeter: calibrated gas evacuation comprising both high and low gas flows

Area of Science:

• Anesthesiology
• Medical Devices
• Gas Dynamics

Background:

• Anesthetic circuits require effective waste gas scavenging to ensure patient and staff safety.
• Existing scavenging systems may have limitations in range or calibration accuracy.
• The wide-range ejector flowmeter is an active scavenging system designed for anesthetic circuits.

Purpose of the Study:

• To evaluate the performance and accuracy of the wide-range ejector flowmeter.
• To assess the consistency of waste gas extraction across a range of settings.

Main Methods:

• Tested three ejector flowmeters under 12 different presettings.
• Measured evacuation rates and compared them to the calibrated scale.
• Calculated percentage deviation from the intended presetting.

Main Results:

• The ejector flowmeter allows adjustable evacuation rates from 200 ml/min to 15 L/min under visual control.
• Percentage deviation from presetting ranged from +18% to -19.4% across tested units and settings.
• The system demonstrated applicability within a wide range of fresh gas flows.

Conclusions:

• The wide-range ejector flowmeter provides consistent and calibrated extraction of waste gases.
• Despite observed deviations, the device is suitable for use in various anesthetic applications.
• Further refinement may improve calibration precision within the operational range.