Arterial Stiffness Calculator

β · DC · Einc and related parameters of local arterial elasticity

Educational tool for assessment of local arterial stiffness

Patient

Input data

Diameters by B-mode / eTracking, pressure at the time of scanning

mm
mm
mm
mmHg
mmHg
yr
Blood density ρ kg/m³

Results

Real-time recalculation · pressure is automatically converted to kPa

Stiffness index β
Stiffness index, pressure-independent
—
Distensibility DC
Distensibility coefficient
—
Young incremental Einc
Incremental elastic modulus of the wall
—
Peterson Ep
Pressure–strain elastic modulus
—
Compliance CC
Compliance coefficient
—
PWV (β) β-PWV
Single-point pulse wave velocity
—

Approximate interpretation

Comparison with the age-related CCA trend (ETIC/Engelen data). Enter age and complete the data.

Enter age, diameters, and pressure — an analysis for each parameter will appear.

Ranges are approximate, based on the age-related trend from reference studies of local CCA stiffness (ETIC, Hitachi-Aloka echo-tracking; Engelen 2015). These are not diagnostic thresholds: strict assessment requires an age/sex-specific ETIC Z-score nomogram using carotid (not brachial) pressure. Stiffness increases with age; β is least pressure-dependent, while Ep and PWV-β are most pressure-dependent. This tool is educational and does not replace a clinical report.

Formulas and units
Strain: relative pulsatile change in diameter. ε = (Ds − Dd) / Dd
β — stiffness index: logarithm of the pressure ratio per unit strain, dimensionless. β = ln(SBP / DBP) / [ (Ds − Dd) / Dd ]
DC — distensibility coefficient: relative change in area per unit pulse pressure. DC = [ (Ds² − Dd²) / Dd² ] / ΔP → ×10⁻³·kPa⁻¹
ΔP = SBP − DBP, converted to kPa (1 mmHg = 0.1333 kPa)
Eₚ — Peterson (pressure-strain) modulus: Ep = ΔP / ε = ΔP · Dd / (Ds − Dd) [kPa]
CC — compliance coefficient: absolute change in lumen area per unit pressure. CC = π · (Ds² − Dd²) / (4 · ΔP) [mm²/kPa]
Einc — Young incremental elastic modulus: accounts for wall geometry through IMT. Einc = 3 · (1 + LCSA/WCSA) / DC [kPa]
LCSA = π·Dd²/4 (lumen); WCSA = π·[ (Dd/2 + IMT)² − (Dd/2)² ] (wall); DC in kPa⁻¹
β-PWV — single-point pulse wave velocity: PWVβ = √( β · DBP / (2ρ) ) [m/s]
DBP in Pa, ρ — blood density (≈1050 kg/m³). Aloka/Hitachi eTracking method.
Medtrain LLC · ultrasound diagnostics

Local Arterial Stiffness Assessment Report

Input data

Calculated parameters

ParameterValueFor age

Local CCA stiffness (Reneman/Hoeks · O'Rourke conventions). Approximate ranges are based on the age-related trend from reference studies (ETIC echo-tracking; Engelen 2015) and are not diagnostic thresholds: strict assessment requires an age/sex-specific Z-score nomogram using carotid pressure. β is least BP-dependent, while Ep and PWV-β are most BP-dependent. This document is educational in nature and does not replace a clinical report.

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