Diffuse Correlation Spectroscopy

Enhancing signal to noise ratio in DCS

Diffuse Correlation Spectroscopy (DCS) is a non-invasive technique that can be used to measure blood flow in tissue. This generally involves coupling laser light from a fibre into the tissue and measuring the scattered light at a distance from the input, also using a fibre.

The further away from the input, the deeper the light will have travelled and the less light emerges, which is where single-photon detection is required.

Photon Force customers using our technology in the DCS field have been able to enhance their signal to noise ratio, allowing otherwise undetectable changes to be seen.

How Duke University utilises the Photon Force PF32 for DCS

At Duke University, Wenhui Liu et al use the Photon Force PF32 SPAD camera’s high frame rates and photon counting mode to record single-photon images at over 300kfps.

In the paper ‘Fast sensitive diffuse correlation spectroscopy with a SPAD array’, the team at Duke detail how they developed a highly parallelized DCS system using the PF32’s 32 x 32 single-photon avalanche diode (SPAD) array and demonstrated its sensitivity improvement in a DMD-based study and an in vivo forehead blood flow experiment.

Essentially, the Duke University experiment showed real-time measurement of blood flow in human tissue.

Image (a) shows the set up for the in vivo forehead blood flow and image (b) demonstrates the results using the Photon Force PF32. Image (c) validates the results by comparing them to results from a commercial electrocardiogram monitor.

Other uses in Diffuse Correlation Spectroscopy

Other ways the Photon Force PF32 has been used for DCS include the exciting developments at Meta Reality Labs, where the team are working on a brain/computer interface using both the Photon Force PF32 camera hardware and our customised, accelerated firmware.

Other uses in Diffuse Correlation Spectroscopy

Other uses in DCS include the exciting developments at Facebook Reality Labs, where the team are working on a brain/computer interface using the Photon Force PF32 and our customised, accelerated firmware.