MCCL Speckle Contrast

[Liban Hussein]

Hello,

I've been able to successfully use the MCCL software to generate fluence plots for penetration depth assessment of lasers with varying wavelengths.

I wanted to see if the tool has a speckle contrast feature (direct speckle contrast simulations for varying wavelengths), or if I'm limited to using the fluence setup.

Best,

Liban Hussein

[Carole Hayakawa]

Hi Liban,

Thanks for letting us know MCCL has been working for you!

MCCL has been used to provide results for a couple of papers having to do with speckle contrast:

1. Caitlin Regan, Carole Hayakawa, and Bernard Choi, "Momentum transfer Monte Carlo for the simulation of laser speckle imaging and its application in the skin," Biomed. Opt. Express 8, 5708-5723 (2017)

2. Rice TB, Kwan E, Hayakawa CK, Durkin AJ, Choi B, Tromberg BJ. Quantitative, depth-resolved determination of particle motion using multi-exposure, spatial frequency domain laser speckle imaging. Biomed Opt Express. 2013 Nov 19;4(12):2880-92. doi: 10.1364/BOE.4.002880. PMID: 24409388; PMCID: PMC3862160.

3. Cody E. Dunn, Ben Lertsakdadet, Christian Crouzet, Adrian Bahani, and Bernard Choi, "Comparison of speckleplethysmographic (SPG) and photoplethysmographic (PPG) imaging by Monte Carlo simulations and in vivo measurements," Biomed. Opt. Express 9, 4306-4316 (2018)

The detectors used in these studies can be found in the sample infile infile_two_layer_momentum_transfer_detectors.txt

Best,

Carole

[Liban Hussein]

Thanks Carole!

Based on your response, where you mention "The detectors used in these studies can be found in the sample infile infile_two_layer_momentum_transfer_detectors.txt":

1. Is there anyway to generate plots for the speckle contrast similar to the fluence plot below, where I can choose to mimic a blood vessel and place it a certain depth to assess depth penetration?

2. Referencing a previous question I had here, what would be the best way to generate speckle contrast plots similar to the figure below to assess penetration depth along with speckle contrast?

Best,
Liban Hussein

[Carole Hayakawa]

Hi Liban,

If I understand your question, you can use the ReflectedDynamicMTOfXAndYAndSubregionHistDetector with a tissue that has an embedded blood vessel.  The indexing of the tissue regions start from 0 and increment for air above, tissue layer, tissue layer, etc. (for how many layers), air below, then cylinder.  So if you have a one layer tissue with a embedded cylinder, indexing is: air above=0, layer=1, air below=2, cylinder=3.  In the specification of the "BloodVolumeFraction" you would specify [0,0,0,0.5] for a blood volume fraction of 50% in the cylinder.

Does this make sense?

Best,

Carole

[Liban Hussein]

Hello Carole,

Yes, that is correct. Is there an example infile I can reference, similar to the infile from this previous chat?

Best,

Liban Hussein

[Carole Hayakawa]

Hi Liban,

You could use the infile from the previous chat and add in the ReflectedDynamicMTOfXAndYAndSubregionHistDetector detector into the list of detectors.  An example of this detector is in the sample infile: infile_two_layer_momentum_transfer_detectors.txt.  You would have to adjust the input of the detector appropriate to your system (what I was trying to explain on Sept. 3 post).

Best,

Carole