Calibrated Doppler Ultrasound Fluid Flow Phantom
Provides straight vascular conduit with acoustic tissue-mimicking phantom and certified backscatter.
Biomedical Engineering / Doppler Ultrasound Velocimetry
FREE TO EXPLORELABORATORY 37 · BIOMEDICAL ENGINEERING
Continuous-Wave Doppler Ultrasound Blood Velocimetry Frequency Shift
Determine the Doppler frequency shift sensitivity k_d and verify the clinical Doppler ultrasound equation using a blood-mimicking fluid string phantom across flow velocities. Explore interactive physiological instrumentation simulation, biomechanics, and biomedical engineering telemetry.
BIOINSTRUMENTATION · BIOSIGNALS · BIOMECHANICS · IMAGING
Your virtual biomedical engineering laboratory.
DOPPLER AUDIO FREQUENCY SHIFT ΔF—
PHYSIOLOGICAL & TEST CELL TELEMETRY
Ready to sample with Velocity v = 30.0 cm/s.
Adjust Velocity v, then execute biomedical trial.
Biomedical engineering telemetry and physiological states are evaluated rigorously using 64-bit IEEE 754 precision. Residuals reflect ordinary least-squares regression across successive observations. Continuous data structures support high-fidelity biological and physiological modeling.
Biomedical assumptions and boundary condition limits
The linear Doppler relation applies across laminar velocities; severe turbulent flow creates broad spectral broadening rather than a single discrete shift. Evaluated using a 4.0 MHz continuous-wave (CW) split-crystal Doppler pencil probe insonating a precision Doppler flow phantom (mimicking carotid blood flow) at an angle of θ = 60.0° in tissue-mimicking fluid (c = 1540 m/s). Theoretical sensitivity k_d = (2 · 4.0×10⁶ · cos(60°)) / (154,000 cm/s) = 25.97 Hz/(cm/s) adjusted for phantom refractive wall geometry to k_d = 28.5000 Hz/(cm/s). Velocities from 10.0 to 60.0 cm/s.
Biomedical apparatus & physiological sensors.
4.0 MHz Continuous-Wave (CW) Dual-Crystal Doppler Probe
Contains separate transmit and receive PZT crystals for continuous Doppler telemetry.
Precision Goniometric Probe Positioning Stage
Sets and maintains exact Doppler insonation angle θ = 60.0° relative to flow lumen axis.
Microprocessor-Controlled Blood-Mimicking Fluid Pump
Circulates blood-mimicking fluid (BMF) containing nylon micro-particles at certified steady velocities.
Quadrature Heterodyne Demodulator & Audio Preamplifier
Mixes RF echoes with carrier f_0 to extract in-phase (I) and quadrature (Q) directional audio signals.
High-Resolution Real-Time Audio Fast Fourier Transform (FFT) Analyzer
Computes power spectral density and identifies modal peak Doppler shift frequency Δf.
FOLLOW THE METHOD
A reason behind every step.
Determine the Doppler frequency shift sensitivity k_d and verify the clinical Doppler ultrasound equation using a blood-mimicking fluid string phantom across flow velocities. Standardized parameter settings: 10.0, 20.0, 30.0, 40.0, 50.0, 60.0 cm/s.
01
Flow Loop Priming and BMF Verification
Fill the flow phantom with certified blood-mimicking fluid (nylon scattering particles, density 1050 kg/m³, c = 1540 m/s) and purge all air bubbles.
02
Goniometric Doppler Angle Alignment
Mount the 4.0 MHz CW Doppler probe on the goniometric stage and position probe at precisely θ = 60.0° relative to the flow channel axis.
03
Zero Flow Demodulator Calibration
With the perfusion pump halted, verify zero Doppler audio frequency shift (Δf = 0.0 Hz) and null baseline wall-filter noise.
04
Steady Velocity Initialization
Engage the calibrated pump driver to produce steady centerline flow velocity v = 10.0 cm/s and allow 60 seconds for steady laminar flow.
05
FFT Power Spectrum Peak Extraction
Execute real-time 1024-point FFT spectral analysis on the demodulated Doppler audio stream, averaging 20 spectra to extract peak frequency shift Δf (Hz).
06
Velocity Progression Sequence
Increment flow delivery through 20.0, 30.0, 40.0, 50.0, and 60.0 cm/s, logging peak Doppler frequency shift Δf at each velocity step.
07
Doppler Sensitivity Linear Regression
Plot Doppler frequency shift Δf versus flow velocity v and determine sensitivity slope k_d via linear regression through the origin.
YOUR NOTEBOOK · 0 OBSERVATIONS
Turn measurements into biomedical engineering insight.
Points are your recorded observations. The solid regression line validates Doppler Ultrasound Velocimetry mathematical scaling.
LINEAR REGRESSION FIT · y = mx + b
Δf = k_d · v = 28.5000 · v (at f₀ = 4.0 MHz, θ = 60°)
| # | Target Flow Velocity v (cm/s) | Doppler Audio Frequency Shift Δf (Hz) | Flow velocity v (cm/s) | Doppler frequency shift Δf (Hz) | Remove |
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