In vitro validation of volumetric blood flow measurement using Doppler flow wire

Area of Science:

• Cardiovascular physiology
• Medical imaging
• Biomedical engineering

Background:

• Accurate volumetric blood flow measurement is crucial for assessing coronary flow and flow reserve.
• Current methods often rely on average peak velocity, neglecting velocity profiles and vessel area changes.
• A novel approach is needed for precise coronary blood flow quantification.

Purpose of the Study:

• To evaluate the feasibility of a new method for calculating volumetric blood flow using Doppler power and a Doppler flow wire.
• To assess the accuracy of this Doppler power-based method against established flow measurement techniques.

Main Methods:

• An in vitro model with silicone tubes and pulsatile flow was used.
• A Doppler flow wire system calculated Doppler moments (M(0), M(1)) and mean flow velocity (V(m)).
• Proximal and distal sample volumes corrected for scattering and attenuation to determine absolute volumetric flow.

Main Results:

• The Doppler power method demonstrated an excellent correlation (0.98, p < 0.0001) with time-collected flow measurements.
• The mean paired flow difference was minimal (1.5 +/- 9.0 mL/min).
• The regression line closely matched the line of equality, indicating high agreement.

Conclusions:

• Direct volumetric blood flow measurement using Doppler power and a flow wire is feasible.
• This technique offers potential for accurate coronary flow and flow reserve assessment.
• The method utilizes a commercially available Doppler flow wire system for clinical application.