Doppler OCT Velocity
Convert Doppler-OCT phase change into axial and angle-corrected flow velocity.
Description
Doppler-OCT phase change converts to axial velocity using a two-way optical phase model.
Doppler-OCT phase change converts to axial velocity using a two-way optical phase model. Angle correction divides by the beam-flow cosine.1
Convert Doppler-OCT phase change into axial and angle-corrected flow velocity.
When to use Doppler OCT Velocity
Use this tool to convert Doppler-OCT phase change into axial and angle-corrected flow velocity.
Prepare the optical measurements, geometry, fitted coefficients or caller-selected thresholds requested. Confirm wavelength, radius/diameter, pulse-width, angle and unit conventions before running the calculation.
How to use Doppler OCT Velocity and understand its results
- Prepare the optical measurements, geometry, fitted coefficients or caller-selected thresholds requested. Confirm wavelength, radius/diameter, pulse-width, angle and unit conventions before running the calculation.
- Enter phaseChangeRadians, wavelengthMeters, refractiveIndex, scanIntervalSeconds, beamAngleDegrees using the field table and calculation rules, then run the tool.
- Read axialVelocityMetersPerSecond, flowVelocityMetersPerSecond. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| phaseChangeRadians | Inter-scan phase change (rad) | number | Required |
| wavelengthMeters | Center wavelength (m) | number; minimum: 0 | Required |
| refractiveIndex | Sample refractive index | number; minimum: 0 | Required |
| scanIntervalSeconds | Scan interval (s) | number; minimum: 0 | Required |
| beamAngleDegrees | Beam-to-flow angle (°) | number; minimum: 0; maximum: 90 | Required |
Enter finite signed phase, nonnegative wavelength, positive index/interval and angle 0–90°. Reject |cosθ|<1e−12. Return signed axial and corrected m/s.
axial=phase×λ/(4πnΔt); flow=axial/cosθ Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| axialVelocityMetersPerSecond | Axial velocity (m/s) | number |
| flowVelocityMetersPerSecond | Angle-corrected flow velocity (m/s) | number |
{
"input": {
"phaseChangeRadians": 3.141592653589793,
"wavelengthMeters": 8e-7,
"refractiveIndex": 1,
"scanIntervalSeconds": 0.001,
"beamAngleDegrees": 60
},
"output": {
"axialVelocityMetersPerSecond": 0.00019999999999999998,
"flowVelocityMetersPerSecond": 0.00039999999999999986
}
}Limitations and assumptions
No phase unwrapping, aliasing, vessel geometry or clinical flow interpretation is supplied.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Doppler Lidar Frequency Shift: Calculate monostatic lidar Doppler frequency shift from radial velocity and wavelength. For a complementary task, use Interferometer Displacement: Convert reflected-path fringe count to displacement with refractive-index and angle correction.
References
-
Doppler OCT Velocity — tool.io
Similar or alternative tools
- Doppler Lidar Frequency Shift
Calculate monostatic lidar Doppler frequency shift from radial velocity and wavelength.
- Interferometer Displacement
Convert reflected-path fringe count to displacement with refractive-index and angle correction.