Evaluation of Nonlinear Wave Separation Method to Assess Reflection Transit Time: A Virtual Patient Study

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Medical Signal Processing

Background:

• Conventional reflection transit time (RTT) calculation relies on pulse counter analysis.
• Current wave separation techniques require simultaneous pressure and flow velocity measurements, limiting clinical application.
• Existing methods face challenges in practical, single-site arterial measurements.

Purpose of the Study:

• To introduce a novel wave separation analysis method for RTT calculation using only a single pulse waveform.
• To overcome the limitations of simultaneous waveform measurements in clinical practice.
• To demonstrate the feasibility of RTT as a surrogate for arterial stiffness assessment.

Main Methods:

• A multi-Gaussian decomposition approach is proposed to analyze a single pulse waveform.
• The pulse waveform is decomposed into Gaussian components and reconstructed based on model criteria.
• Reflection transit time (RTT) is determined by the time difference between normalized forward and backward waveforms, without needing flow velocity data.

Main Results:

• The proposed method demonstrated feasibility in calculating RTT from a single pulse waveform.
• A strong correlation (r>0.79, p<0.0001) was observed between the calculated RTT and established arterial stiffness markers (Ep, PWV, β, AC).
• The strongest correlation was found between RTT and arterial compliance (AC).

Conclusions:

• This simulation study validates a new, simplified method for RTT calculation using single pulse waveform analysis.
• The findings support the link between pulse wave reflections and arterial stiffness.
• The method offers a promising, clinically relevant approach for assessing arterial stiffness and cardiovascular health.