title: Calibration of diffuse correlation spectroscopy blood flow index with venous-occlusion diffuse optical spectroscopy in skeletal muscle.
abstract: We investigate and assess the utility of a simple scheme for continuous absolute blood flow monitoring based on diffuse correlation spectroscopy (DCS). The scheme calibrates DCS using venous-occlusion diffuse optical spectroscopy (VO-DOS) measurements of arm muscle tissue at a single time-point. A calibration coefficient (γ) for the arm is determined, permitting conversion of DCS blood flow indices to absolute blood flow units, and a study of healthy adults (N=10) is carried out to ascertain the variability of γ. The average DCS calibration coefficient for the right (i.e., dominant) arm was γ=(1.24±0.15)×10(8) (mL·100  mL(−1)·min(−1))/(cm(2)/s). However, variability can be significant and is apparent in our site-to-site and day-to-day repeated measurements. The peak hyperemic blood flow overshoot relative to baseline resting flow was also studied following arm-cuff ischemia; excellent agreement between VO-DOS and DCS was found (R(2)=0.95, slope=0.94±0.07, mean difference=−0.10±0.45). Finally, we show that incorporation of subject-specific absolute optical properties significantly improves blood flow calibration accuracy.
authors.affiliation: University of Pennsylvania, Department of Physics & Astronomy, 209 South 33rd Street, Philadelphia, Pennsylvania 19104, United StatesbTianjin University, School of Precision Instrument and Opto-Electronics Engineering, Tianjin 300072, ChinacTianjin Univer.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Li
authors.affiliation: University of Pennsylvania, Department of Physics & Astronomy, 209 South 33rd Street, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Wesley B
authors.initials: WB
authors.lastname: Baker
authors.affiliation: University of Pennsylvania, Department of Physics & Astronomy, 209 South 33rd Street, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Ashwin B
authors.initials: AB
authors.lastname: Parthasarathy
authors.affiliation: University of Pennsylvania, Department of Bioengineering, 210 South 33rd Street, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Tiffany S
authors.initials: TS
authors.lastname: Ko
authors.affiliation: University of Pennsylvania, Department of Physics & Astronomy, 209 South 33rd Street, Philadelphia, Pennsylvania 19104, United StateseInstitute of Fluid Physics, Mianyang 621000, China.
authors.forename: Detian
authors.initials: D
authors.lastname: Wang
authors.affiliation: University of Pennsylvania, Department of Physics & Astronomy, 209 South 33rd Street, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Steven
authors.initials: S
authors.lastname: Schenkel
authors.affiliation: ICFO-Institut de Ciéncies Fotóniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain.
authors.forename: Turgut
authors.initials: T
authors.lastname: Durduran
authors.affiliation: Tianjin University, School of Precision Instrument and Opto-Electronics Engineering, Tianjin 300072, ChinacTianjin University, State Key Laboratory of Precision Measurement Technology and Instruments, Tianjin 300072, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.affiliation: University of Pennsylvania, Department of Physics & Astronomy, 209 South 33rd Street, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Arjun G
authors.initials: AG
authors.lastname: Yodh
mesh_terms: D000328:Adult; D002138:Calibration; D005260:Female; D064368:Healthy Volunteers; D006439:Hemodynamics; D006801:Humans; D007511:Ischemia / Q000473:pathology; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply*; D055095:Optics and Photonics; D010101:Oxygen Consumption / Q000502:physiology; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D013053:Spectrophotometry / Q000379:methods*; D019265:Spectroscopy, Near-Infrared / Q000379:methods