A Device-on-Chip Solution for Real-Time Diffuse Correlation Spectroscopy Using FPGA.

Area of Science:

• Biomedical optics
• Medical instrumentation
• Signal processing

Background:

• Diffuse correlation spectroscopy (DCS) enables non-invasive assessment of deep tissue blood perfusion.
• High computational demands of traditional DCS hinder real-time applications.
• Existing DCS systems are often bulky and expensive due to computational hardware.

Purpose of the Study:

• To develop a compact, integrated device-on-chip solution for DCS.
• To enable real-time calculation of blood flow index (BFI).
• To reduce the cost and footprint of DCS computational components.

Main Methods:

• Implementation of a novel DCS system on a field-programmable gate array (FPGA) chip.
• Integration of a multi-tau correlator for autocorrelation function calculation.
• Inclusion of a DCS analyzer for real-time BFI derivation via curve fitting.
• Evaluation using phantom and cuff ischemia studies, comparing against a lab-standard DCS system.

Main Results:

• The FPGA-based DCS system achieved a calculation rate of 6000 BFIs/s.
• High correlation between the FPGA DCS and reference DCS for light correlation and BFI.
• Demonstrated a measurement rate of 50 Hz, capable of resolving pulsatile blood flow.
• Successful validation in phantom and cuff ischemia studies.

Conclusions:

• The integrated FPGA DCS system provides accurate and real-time blood flow monitoring.
• This device-on-chip solution significantly reduces computational cost and system size.
• Enables the development of portable, cost-effective, and real-time DCS systems for broader clinical and research applications.