one specific velocity color mapping of flows with complex geometry n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
One Specific Velocity Color Mapping of Flows with Complex Geometry PowerPoint Presentation
Download Presentation
One Specific Velocity Color Mapping of Flows with Complex Geometry

Loading in 2 Seconds...

play fullscreen
1 / 15

One Specific Velocity Color Mapping of Flows with Complex Geometry - PowerPoint PPT Presentation


  • 75 Views
  • Uploaded on

One Specific Velocity Color Mapping of Flows with Complex Geometry. S.G.Proskurin, A. Yu. Potlov, K.E.S.Ghaleb. Biomedical Engineering, Tambov State Technical University, Russia. abstract. Conventional OCT-systems has a bandpass filter centered at carrier frequency, f c

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'One Specific Velocity Color Mapping of Flows with Complex Geometry' - penney


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
one specific velocity color mapping of flows with complex geometry

One Specific Velocity Color Mapping of Flows with Complex Geometry

S.G.Proskurin,

A.Yu.Potlov, K.E.S.Ghaleb

Biomedical Engineering,

Tambov State Technical University,

Russia

abstract
abstract

Conventional OCT-systems has a bandpass filter centered at carrier frequency, fc

Application of analog and digital tunable filters in the signal processing gives new possibilities

By changing bands of the filters it is possible to distinguish Doppler shift in the spectrum of the signal

what wavelengths
what wavelengths?

red dotted ellipses show wavelengths

with minimum absorption in tissues

slide4

experimental set-up

ODL

tunable filter

D1

D2

SLD – superluminescent diode, FC1 and FC2 – fiber couplers, L – collimating and focusing optics, ODL – optical delay line, D1 and D2 – balanced detectors, α – the angle between incident light and the direction of the fluid flow velocity.

Scanning is performed along X-axis

slide5

hydrodynamic phantoms

tilted capillary entry was used in the experiment

capillary entry

tilted capillary entry

doppler spectra of interference signal from a flow with parabolic velocity profile

Doppler spectra of interference signal from a flow with parabolic velocity profile

ΔV/V ~ 7%

by choosing fcand Δfc we could obtain equidvelocity images

slide7

processingthe signal

a new algorithm of color Doppler mapping of one specific

velocity (OSV) of shuttle flows is applied

it is realized using the separation of the raw data to two

parts corresponding to positive and negative shifts

of the carrier frequency

it does not have 2π-ambiguity disadvantage

of color Doppler OCT images

slide8

panel 1 of processing interference

final complexing

standard structural image

QuantumElectronics (2013) submitted

slide9

panel 2 of processing interference

negative direction OSV image

positive direction OSV image

QuantumElectronics (2013) submitted

slide10

processingthe signal

as a final result, the complexation of independently

reconstructed structural image (green) and 2D color-coded

OSV images (red and blue) is performed

practical implementation of the algorithm was performed

using the stream programming in the LabVIEW package

slide11

panel 3 of processing interference

final structural image

both OSV images

QuantumElectronics (2013) submitted

image of subcutaneous human blood vessel and blood in vivo
image of subcutaneous human blood vessel and blood in vivo

the described approach is applicable to blood flow monitoring in subcutaneous human blood vessels

it gives quantitative information about the chosen value of velocity determined by the Doppler angle and shift of the carrier

Proskurin S.G.,

QuantumElectronics (2012) p.495

conclusion
conclusion

the described algorithm does not have disadvantage of 2π-ambiguity, as in a conventional qualitative color systems, where shift of adjacent A-scans is detected

determined by the registered shift of the carrier OSV mapping gives quantitative information about the chosen velocity value and direction of the flow

averaging over several consecutive A-scans reduces speckles noise, increases contrast and looses information about A-scan phase, but keeps information about Doppler shift itself

references
references

Proskurin S.G. Potlov A.Yu.,FrolovS.V., Doppler mapping of sign-variable flow with complex geometry using optical coherence tomography// QuantumElectronics, (2013) submitted

Proskurin S.G., Raster scan and averaging for speckle reduction in optical coherence tomography// QuantumElectronics, Vol. 42 (6), p. 495-499, 2012

Proskurin S.G., FrolovS.V., Visualizationofbloodvesselsbymeansofopticalcoherencetomography // BiomedicalEngineering, No.3, p.9-14, 2012

Proskurin S.G., Meglinski I.V., Optical coherence tomography imaging depth enhancement by superficial skin optical clearing // Laser Physics Letters, Vol. 4, No. 11, p. 824-826, 2007

one specific velocity color mapping of flows with complex geometry1

One Specific Velocity Color Mapping of Flows with Complex Geometry

S.G.Proskurin,

A.Yu.Potlov, K.E.S.Ghaleb

Biomedical Engineering,

Tambov State Technical University,

Russia