Reproducibility of cutaneous thermal hyperaemia assessed by laser Doppler flowmetry in young and older adults

Axon reflex-related hyperemia induced by short local heating is reproducible

“…The reproducibility of baseline CVC and percentage of peak CVC change were not acceptable in the present study, consistent with previous reports that showed poor reproducibility when the data were expressed as baseline CVC or a form that involved baseline Time (min) CVC, such as peak CVC change and percentage of peak CVC change (Agarwal et al, 2010;Roustit et al, 2010a,b;Tew et al, 2011).…”

“…Within-subject coefficient of variation (CV) and intra-class correlation coefficient (ICC[2,1]) were used to test the reproducibility of the measurements of the hyperemic response (Agarwal et al, 2010;Bland, 2000;Roustit et al, 2010a,b;Tew et al, 2011). The CV values were calculated using the root mean square method and CV values of b 10%, 10-25%, and >25% represented good, moderate, and poor reproducibility, respectively (Iellamo et al, 1996).…”

“…The poor reproducibility of LTH at random recording sites measured by single-point LDF (Roustit et al, 2010a) could be improved when an integrated probe (Tew et al, 2011), laser Doppler imager (LDI) or laser speckle contrast imager (LSCI) (Roustit et al, 2010b) with an increased recording area was used. Because the holder of an integrated probe combined with a heating probe (34 mm for PeriMed PH 13) or a LDI/LSCI heating probe (35 mm for Moor SHP3) is markedly larger than the holder of a single-point probe combined with a heating probe (22 mm for Moor PH1-V2), they are difficult to apply to several locations on the body, such as uneven regions of the head, trunk, and extremities, or smaller regions of the body, such as fingers and toes, further limiting their use.…”

“…The AR flare response is affected by the spatial heterogeneity of capillary density (Braverman et al, 1990;Cracowski et al, 2006;Wårdell et al, 1994). Therefore, when testing a random recording site, heating for longer than 30 min to gain peak cutaneous vascular conductance (CVC) from the plateau or maximal dilatation phase is needed to normalize the initial peak CVC as a percentage of the plateau peak or percentage of the maximum for comparison (Minson et al, 2001;Roustit et al, 2010a,b;Tew et al, 2011). The initial peak is enhanced and the plateau peak is inhibited in the second test at a 2 h interval (Ciplak et al, 2009;Frantz et al, 2012).…”

Local Thermal Impact on Microcirculation Assessed by Imaging Photoplethysmography

“…Among these methods, LDF is the most widespread technique for assessment of tissue perfusion. It provides quantitative estimations of relative changes in blood perfusion in response of various external impacts [5][6][7]. However, LDF probes operate in a single-point, which lead to spatial variability and poor reproducibility of results [8].…”