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A multipixel diffuse correlation spectroscopy system based on a single photon avalanche diode array.

Johannes D Johansson1, Davide Portaluppi2, Mauro Buttafava2

  • 1Department of Biomedical Engineering, Linköping University, Linköping, Sweden.

Journal of Biophotonics
|July 25, 2019
PubMed
Summary
This summary is machine-generated.

A new multipixel system using single photon avalanche diodes (SPADs) enhances noninvasive blood flow monitoring. This approach improves signal-to-noise ratio for techniques like laser Doppler flowmetry and diffuse correlation spectroscopy.

Keywords:
SPAD arrayblood flow measurementsdiffuse correlation spectroscopylaser Doppler flowmetry

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Area of Science:

  • Biomedical Optics
  • Photonics
  • Medical Imaging

Background:

  • Laser speckle autocorrelation quantifies blood flow changes noninvasively.
  • Techniques like laser Doppler flowmetry (LDF) and diffuse correlation spectroscopy (DCS) utilize this principle.
  • Combining LDF's multi-detector approach with DCS's sensitivity is desirable.

Purpose of the Study:

  • To develop and evaluate a novel multipixel system for enhanced blood perfusion monitoring.
  • To integrate the strengths of LDF and DCS using a 2D array of single photon avalanche diodes (SPADs).

Main Methods:

  • A 2D SPAD array was employed to capture laser speckle patterns.
  • System performance was assessed using milk phantoms with varied parameters (fiber diameter, source-detector separation, fiber-SPAD distance, measurement time, temperature).
  • An in vivo blood occlusion test was conducted to validate the system.

Main Results:

  • The multipixel system demonstrated improved signal-to-noise ratio (SNR).
  • Utilizing a multimode detector fiber proved beneficial for SNR in this specific setup.
  • The system showed promise in detecting changes in blood flow during the occlusion test.

Conclusions:

  • The developed multipixel system is functional for noninvasive blood flow estimation.
  • Further research is required to optimize data acquisition and system settings.
  • The system holds potential for advancing optical techniques in blood perfusion monitoring.