Transit time flow measurement: experimental validation and comparison of three different systems

Area of Science:

• Vascular Surgery
• Medical Devices
• Hemodynamics

Background:

• Accurate blood flow measurement is crucial for vascular surgery quality control.
• Detecting low-flow states is essential to prevent adverse patient outcomes.
• Validation of blood flow measurement systems is needed for clinical application.

Purpose of the Study:

• To validate three different flow systems for measuring absolute blood flow.
• To assess the accuracy and reproducibility of transit time flow measurements.
• To compare system performance under various experimental conditions.

Main Methods:

• Experimental flow model using arteries and veins.
• Measurements conducted with blood and saline at different temperatures.
• True flow determined by volume sampling as the reference method.

Main Results:

• Initial correlation coefficients (0.71-0.92) showed variability.
• Systematic over/underestimation of transit time flow was observed.
• Second-order correction resulted in excellent correlations (0.93-0.95) regardless of medium or temperature.

Conclusions:

• Transit time flow measurements are exact and reproducible.
• Second-order correction significantly improves accuracy and precision.
• The three evaluated systems demonstrated minimal performance differences.