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Updated: Jul 9, 2026
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Blood Flow Imaging with Ultrafast Doppler
Published on: October 14, 2020
Fiber-based multispeckle detection for time-resolved diffusing-wave spectroscopy: characterization and application to
G Dietsche1, M Ninck, C Ortolf
1Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany.
Applied Optics
|December 12, 2007
Summary
This study introduces a fast method for measuring light scattering dynamics, enabling real-time analysis of blood flow in deep tissues by averaging multiple speckle signals.
Area of Science:
- Biophysics
- Photonics
- Medical Imaging
Background:
- Accurate measurement of temporal field autocorrelation functions is crucial for understanding light scattering in biological tissues.
- Existing techniques often require long acquisition times, limiting the study of dynamic processes like blood flow.
- Diffusing-wave spectroscopy (DWS) is a powerful tool, but its application to nonstationary dynamics has been challenging.
Purpose of the Study:
- To develop and validate a novel technique for rapid measurement of temporal field autocorrelation functions of multiply scattered light.
- To enable the study of nonstationary scatterer dynamics in biological tissues with high temporal resolution.
- To apply the technique for in vivo measurements of blood flow in deep tissues.
Main Methods:
- Utilized parallel detection and autocorrelation of intensity fluctuations from multiple independent speckles using a fiber bundle and avalanche photodiode array.
- Employed a multichannel autocorrelator with variable integration times (6.5–104 ms) for efficient data acquisition.
- Averaged autocorrelation functions from different speckles to drastically reduce overall experiment integration time.
Main Results:
- Achieved subsecond acquisition times for temporal field autocorrelation functions of multiply scattered light.
- Demonstrated the ability to resolve nonstationary scatterer dynamics through single-trial measurements.
- Successfully applied the technique to measure arterial and venous blood flow in deep tissue, revealing significant pulsatile variations.
Conclusions:
- The developed technique significantly reduces acquisition time in diffusing-wave spectroscopy experiments.
- This advancement allows for the resolution of nonstationary dynamics, crucial for physiological measurements.
- The method provides new insights into the pulsatile nature of blood flow in deep tissues.
