Diffuse Correlation Spectroscopy to Measure Cerebral Blood Flow in a Human Subject

Abstract

Source: Menezes Forti, R. et al. Real-Time Monitoring of Neurocritical Patients with Diffuse Optical Spectroscopies. J. Vis. Exp. (2020)

This video demonstrates the use of Diffuse Correlation Spectroscopy (DCS) to measure cerebral blood flow in humans. It outlines the steps for preparing the system, calibrating the probe, positioning it on the participant’s forehead, acquiring scattered light data, and analyzing intensity fluctuations to interpret blood flow dynamics in the brain.

Protocol

All procedures involving human participants have been performed in compliance with the institutional, national, and international guidelines for human welfare and have been reviewed by the local institutional review board.

1. Preparations before moving the system to the intensive care unit (ICU)

1. Connect all the fibers to the relevant lasers and detectors, and make sure they are properly attached to the optical probe (Figure 1B).
2. Check that the optical probe is covered with a black cloth to avoid the lasers shining in the room.
3. Turn the system power switch to the ‘ON’ position. After powering the system, wait 30....

Results

Figure 1: The optical environment developed to monitor patients inside an intensive care unit.

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
3D Printer	Sethi3D	S2	3D-printer used to print the customizable probes
Arduino UNO	Arduino	UNO REV3	Microcontroller responsible to interleave the DCS and FD-DOS measurements
DCS Correlator	Correlator.com	Flex11-16ch	Component of the DCS module
DCS Dectectors IO Boards	Excelitas Technology	SPCM-AQ4C-IO	Component of the DCS module
DCS Detectors	Excelitas Technology	SPCM-AQ4C	Component of the DCS module
DCS Laser	CrystaLaser	DL785-120-SO	Component of the DCS module
DCS Power supply	Artesyn	UMP10T-S2A-S2A-S2A-S2A-IES-00-A	Component of the DCS module (power supply for the DCS detecto; 2, 5 and 30V)
FD-DOS fibers	ISS	Imagent supplies	The fibers used for FD-DOS detection and illumination are provived by ISS
Flexible 3D printer material	Sethi3D	NinjaFlex	Material used to print the flexible customizable probes
Imagent	ISS	Imagent	FD-DOS module
Laser safety googles	Thorlabs	LG9
Multi-mode fiber	Thorlabs	FT400EMT	Multi-mode fiber used for DCS illumination
Neutral density filter 1.0 OD	Edmund Optics	53-705	Neutral density filter for the short source detector separations
Single-mode optical fiber	Thorlabs	780HP	Single-mode optical fiber used for the DCS detectors
System battery	SMS	NET4	System battery used for transportation