We report a low-cost compact diffuse speckle contrast flowmeter (DSCF) consisting of a small laser diode and a bare charge-coupled-device (CCD) chip, which can be used for contact measurements of blood flow variations in relatively deep tissues (up to ∼8 mm). Measurements of large flow variations by the contact DSCF probe are compared to a noncontact CCD-based diffuse speckle contrast spectroscopy and a standard contact diffuse correlation spectroscopy in tissue phantoms and a human forearm. Bland–Altman analysis shows no significant bias with good limits of agreement among these measurements: 96.5% ± 2.2% (94.4% to 100.0%) in phantom experiments and 92.8% in the forearm test. The relatively lower limit of agreement observed in the in vivo measurements (92.8%) is likely due to heterogeneous reactive responses of blood flow in different regions/volumes of the forearm tissues measured by different probes. The low-cost compact DSCF device holds great potential to be broadly used for continuous and longitudinal monitoring of blood flow alterations in ischemic/hypoxic tissues, which are usually associated with various vascular diseases.
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The authors acknowledge funding support from the National Institutes of Health (NIH) R01-CA149274 (G. Yu) and R21- AR062356 (G. Yu). We also acknowledge the support from UKY Reese S. Terry professorship (J. T. Hastings), Global PhD Fellowship Program NRF-2015H1A2A1032268 (M. Seong) and the Department of Biomedical Science and Engineering in the Gwangju Institute of Science and Technology (J. G. Kim), Republic of Korea.
Huang, Chong; Seong, Myeongsu; Morgan, Joshua Paul; Mazdeyasna, Siavash; Kim, Jae Gwan; Hastings, Jeffrey Todd; and Yu, Guoqiang, "Low-Cost Compact Diffuse Speckle Contrast Flowmeter Using Small Laser Diode and Bare Charge-Coupled-Device" (2016). Biomedical Engineering Faculty Publications. 18.