To apply retinal capillary blood flow measurements using Scanning laser Doppler Flowmetry(SLDF) to clinical use, they should be reproducible and no interpersonal difference in nomal subject. Furthermore, the method of measurements must be simple, standardized and show acceptable range of error. We studied 10 eyes of 10 healthy normal subjects. Each subject was scanned in 2 sessions which were separated by at least 2 hours. In each session, we obtained 5 scans and measured macular capillary blood flow in two elected areas from the scanning images. The coefficients of variation of volume, flow, and velocity at each area were ranged from 3.4 to 13.2% 1.4 to 16.9%, and 3.1 to 14.3%, respectively, The reproducibility of measurements was good at each corresponding areas in each subject. No statistically significant locational difference was observed(Kolmogorov-Smirnov test, p>0.05). The Spearman rank correlation coefficients(r) were volume 0.75, flow 0.71, and velocity 0.73. They showed relatively significant correlation between first and second sessions. But there were signigicant differences on interpersonal difference in all 3 parameters: volume, flow, and velocity(Kruskal-Wallis one way ANOVA test. p<0.05). The comparison of measurements between different persons was not meaningful.
Capillaries* ; Humans ; Laser-Doppler Flowmetry* ; Retinaldehyde

The survival of flap has a vital importance in the reconstructive surgery. This study was designed to investigate the relation of the survival area and the variation of flow value measured by laser Doppler flowmetry and to elucidate the effect of PGE1 on flap survival with an objective index. Sixteen New Zealand White rabbits were divided into 3 groups (8 of control group, 4 of intravenous PGE1 group and 4 of topical PGE1 group). The lower abdominal island flap (10 x 5 cm) based on the superficial epigastric pedicle was elevated and reset again at the previous location. The flow values were checked and it was taken as the value of LD. LD ratio was obtained by calculating the ratio of LD value in each experimental period to that of the baseline data taken before flap elevation. Finally, the data of flap survival area on the 8th experimental day was collected by using the plannimetry method. The results: the survival areas of intravenous PGE1 group (72.0 +/- 22.3%) and topical PGE1 group (78.0 +/- 22.7%) showed a significant increase compared to that of control group (46.5 +/- 14.3%, p < 0.01). The flap survival has the close relationship of the LD ratio measured immediately after flap elevation. The neovascularization period for the survival is considered at least 6 days. In conclusion, these experimental results can show an evident relation between the survival area of the flap and the LD ratio value measured immediately after the flap elevation. The LD ratio value measured immediately after flap elevation has the great significance as a critical limit for expecting the fate of flap survival. Therefore this value will be used as one of the beneficial standards for expecting the prognosis of microsurgical reconstruction in clinical trials.
Alprostadil* ; Laser-Doppler Flowmetry* ; Prognosis ; Rabbits

BACKGROUND: Soaps are the most widely used body cleanser and sometimes cause irritation of the skin. OBJECTIVE: Our purpose was to compare the skin irritancy of 6 soaps using noninvasive techniques. METHODS: The skin responses to patch test with 6 soaps were measured by visual scoring, evaporimeter and corneometer. RESULTS: The results are summarized as follows. 1. F soap was shown to cause the least irritancy measured by visual scoring and corneometer. But using evaporimeter, there were no differences in irritancy between the 6 soaps. 2. Through correlation analysis, we found that the evaluation of the evaporimeter was closely related to visual measurement. CONCLUSION: Soap irritancy can be measured by noninvasive techniques, such as the evaporimeter, corneometer, laser doppler flowmetry and visual scoring. Further study of evaluation after short and repeat contacts with soap are needed.
Laser-Doppler Flowmetry ; Patch Tests ; Skin ; Soaps*

Two-D liquid velocity field in a tube with a combination of a stenosis and a bifurcation was measured with refractive index matching technique using Laser Doppler Velocimeter (LDV). The flow ratio of main tube to bypass was 1:4. It is found that the axial velocity profile has two peaks in the XOY plane which is skewed to the main tube wall facing the flow from the bypass, and it manifests itself in the form of "M" in the XOZ plane. A two counter-rotating vortices in the main tube cross section downstream the conjunction region is also detected.
Laser-Doppler Flowmetry ; instrumentation ; methods ; Rheology

A new technique, the laser-doppler flowmetry. has been used intraoperatively to measure blood flow responses in the normal brain tissue, the traumatic brain tissue and so on. The flow estimate by this technique is based on the assessment of the doppler shift of the low power laser light, which is scattered by moving red blood cells.
Brain ; Craniotomy* ; Doppler Effect ; Erythrocytes ; Homeostasis ; Laser-Doppler Flowmetry

BACKGROUND: The mechanism of enhancing effect of ultrasound on the percutaneous absorption of a drug is unclear. But thermal, chemical and mechanical effects are assumed to play a role in enhancing transdermal drug delivery. OBJECTIVE: The aim of this study was to determine if ultrasound enhances percutaneous absorption of methyl nicotinate(MN) without raising the skins surface temperature. METHODS: Treatment consisted of the application of ultrasound massage(1.0 MHz, 1.0 watt/cm2, continuous output) or placebo massage(0 MHz) for 3 min to the forearms of the volunteers, followed by a standardized application of MN at intervals of 15 sec and 10 min postmassage. Percutaneous absorption of MN was monitored using laser doppler flowmetry. RESULTS: 1. Data from the ultrasound treated sites after 15 sec showed significant decrease(p<0.05, paired t-test) in the T(0)(time between MN application and its initial response), T(MAX)(time between MN application and maximuvi response) and increase in the LDF(MAX) .(maximum cutaneous blood flow) compared to those of the control sites. 2. Data from the ultrasound treated sites after 10 min showed no difference in the T(0) and T(MAX) but significant increase in the LDF(MAX) compared to those of the control sites. 3. Data from ultrasound trvated sites both after 15 sec and 10 min showed significant increase in basal cutaneous blood flow(LDF(DH2O)) compared to those of the control sites. 4. There was no difference between the ultrasound treated sites and the control sites in the skins surface temper ature. CONCLUSION: The results of this study suggest that ultrasound may affect the skin structure to provide skin penetration enharcement even without raising the skins surface temperature.
Forearm ; Laser-Doppler Flowmetry ; Niacin* ; Skin ; Skin Absorption* ; Ultrasonography* ; Volunteers

Microsurgery has developed over the last three decades to become a routine surgical operation and it's indications for autogenous tissue transplant have been increased. Despite of initial success rate ranging from 80 to 95 percent, the compromise of vascular pedicle causing flap loss has been still one of the serious complications in the microsurgery. As the success of re-exploration is inversely proportional to the time elapsed till the clinical recognition of vascular complication after operation, early detection of perfusion compromise is an important determinant of flap salvage. In this sense, the laser doppler flowmetry has been widely used as an objective monitoring system for the flap survival. This study was designed to investigate the critical time point of flap survival and to estimate the variation of flow value measured by laser doppler flowmetry. Sixteen New Zealand white rabbits weighed from 1.5 kg to 2 kg were used. The lower abdominal island flap(10 5 cm) based on the superficial epigastric pedicle was elevated and repositioned again. The flow values were checked before the flap elevation, immediately after the flap elevation. And thereafter, they were also checked before and after the ligation of pedicle at the 6th, 8th, 10th, 12th, 14th and 16th day of experimental period. After a preliminary study, additional 5 rabbits on each 14th and 16th experimental day were included in the same experimental procedure. The LD value in each point was measured with the laser doppler flowmetry and it was taken as the value of LD at the experimental time. After that, LD ratio(D/C) was obtained by calculating the ratio of LD value(D) after pedicle ligation to that(C) before pedicle ligation in each experimental period. The flap necrosis was noted from the 6th postoperative day to the 12th postoperative day after the pedicle ligation. On the 14th day after the operation, flap survival was noticed after the pedicle ligation. In the group of flap necrosis, LD ratio(D/C) from the 6th day to the 12th postoperativ
Laser-Doppler Flowmetry* ; Ligation ; Microsurgery ; Necrosis ; Perfusion ; Rabbits ; Transplants

The objective of this study was to evaluated the ariability of measurements of the optic nerve head(ONH) and peripapillary retinal blood flow using Heidelberg Retina flowmeter. Ten eyes of 10 ocularly normal subjects underwent scanning laser Doppler flowmetry. Each eye was scanned in 2 sessions which were separated by 30 minutes. In each session, 5 scans centerd on the ONH using a 10*2.5 degree scan angle were obtained. We identified 10 locations(4 locations in the cup of ONH) and took measurements at the same locations in all scans. The coefficient of variation(CVs, %) for volume, flow, and velocity ranged from 8.1 to 13.0%, 9.9 to 16.0%, and 9.9 to 14.6%, respectively. The CVs of measurements in the neural rim, peripapillary retina, and cup ranged from 9.1to 15.9%, 8.1 to 10.7%, and 11.8 to 16.0%, respectively. The Pearson's coefficients of correlation (r) showed significant correlation in the all parameters in the peripapillary retina and in the flow and velocity in the neural rim. In conclusion, scanning laser Doppler flowmetry provides reproducible measurement of ONH and retinal blood flow.
Flowmeters ; Laser-Doppler Flowmetry* ; Optic Disk* ; Optic Nerve* ; Retina ; Retinaldehyde*

We evaluated the effect of nicotinamide on cellular O2 consumption and metabolic status i.e., adenylate phosphates and NAD+ in-vitro, and changes in blood flow in-vivo, to determine whether changes in cellular metabolism or increased oxygen availability, was responsible for increased tumor oxygenation. Thirty min. Pre-incubation of cells with~4mM (=500mg/kg) nicotinamide resulted in no change in cellular O2 consumption. Similarly, neither the adenylate phosphates nor the cellular NAD+ levels were altered in the presence of~4mM nicotinamide. In-vivo, nicotinamide (500mg/kg) increased O2availability as estimated by changes in relative tumor blood flow (RBC flux). The changes in RBC flux measured by the laser Doppler method, were tumor volume dependent and increased from~35% in~150mmdegree tumors to~75% in~500mmdegree tumors. In conclusion, these observations indicate a reduction in local tissue O2 consumption is not a mechanism of improved tumor oxygenation by nicotinamide in FsaII murine tumor model. The primary mechanism of increased pO2 appears to be an increased local tumor blood flow.
Laser-Doppler Flowmetry ; Metabolism ; Niacinamide ; Oxygen ; Phosphates ; Tumor Burden

We report a case of arteriovenous fistula involving the external ear in a 27- year-old male patient, who presented with pruritic erythematous scaly patch with multiple pulsating nodules on the thickened and hypertrophied left auricle.The blood flow, measured by laser Doppler velocimetry, was increased markedly on the affected site comparing with the other (710.33mV vs 8.4mV, 663.33mV vs 107. 33mV). We suggest that macrotia must be considered as the one of the clinical manifestations of cutaneous arteriovenous fistula.
Arteriovenous Fistula* ; Ear, External ; Humans ; Laser-Doppler Flowmetry ; Male