PULSE-WAVEFORM AND LASER-DOPPLER INDICES FOR IDENTIFYING COLORECTAL-CANCER PATIENTS

2020 ◽  
pp. 2150005
Author(s):  
Chao-Tsung Chen ◽  
Chin-Tsing Ting ◽  
Chun-Yeh Chen ◽  
Zong-Jhe Lyu ◽  
Chien-Cheng Chen ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Blood Flow ◽  
Pulse Wave ◽  
Skin Surface ◽  
Laser Doppler ◽  
Waveform Analysis ◽  
Arterial Pulse ◽  
Doppler Flowmetry ◽  
Control Subjects ◽  
Arterial Pulse Wave

This study aimed to determine the effectiveness of using noninvasive arterial pulse-wave and laser-Doppler flowmetry (LDF) measurements to discriminate between colorectal-cancer (CC) patients and healthy control subjects. Radial-artery blood pressure waveform (BPW), finger photoplethysmography (PPG), and skin-surface LDF signals were measured noninvasively in 12 CC patients and 25 control subjects. Beat-to-beat, spectral, and variability analyses were applied to 20-minute-long recorded signals. Significant intergroup differences were found. In BPW, [Formula: see text]–[Formula: see text] amplitude indices were significantly larger while [Formula: see text]–[Formula: see text] phase-angle indices were significantly smaller in the CC patients than in the controls. The PPG and LDF variability indices were significantly larger and smaller, respectively, in CC patients. The relative energy contributions of the endothelial-, neural-, and myogenic-related frequency bands in LDF were significantly smaller in CC patients. The present findings indicate that pulse and LDF waveform analysis can be used to evaluate the arterial pulse-wave transmission condition, the responses of the blood-flow perfusion, and its regulatory activities in CC patients. There could be some similarities and differences in the present indices for different types of cancer. These findings could be utilized in the development of a rapid, noninvasive, and objective technique for evaluating the CC-induced blood-flow responses.

Persistence of Asymmetry in Nonaxisymmetric Entry Flow in a Circular Cylindrical Tube and Its Relevance to Arterial Pulse Wave Diagnosis

1989 ◽  
Vol 111 (1) ◽  
pp. 37-41 ◽  
Author(s):  
H. Xue ◽  
Y. C. Fung
Keyword(s):  
Blood Flow ◽  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Velocity Profile ◽  
Radial Artery ◽  
Pulse Wave ◽  
Arterial Blood Flow ◽  
Arterial Pulse ◽  
Entry Length ◽  
Arterial Pulse Wave

In an experiment motivated by the study of arterial blood flow along the lines suggested by the traditional Chinese medicine, the flow in a pipe whose lumen was blocked by a semi-circular plug two tube-diameters long was visualized by suspended particles, recorded by cinematography, and analyzed digitally. The Reynolds number was in the range of 100 to 450 based on the pipe diameter, similar to that of blood flow in the radial artery in the arms of man. The blockage was found to have a profound effect on the velocity profile of the flow in the wake, but it had little influence on the symmetry of the velocity profile upstream of the block, except in its immediate neighborhood. When the end conditions far away from the block were steady, the flow in the wake was steady. The asymmetry of the flow in the wake can be judged by the deviation of the location of the maximum axial velocity from the center line of the pipe as seen in the plane of symmetry of the blockage. Our results show that the deviation can be described as the sum of two components. The first is a strong one which decays exponentially in an entry length which is about twice as long as the classical Boussinesq entry length of axisymmetric flow. The second is a weaker component which is wavy spatially and persists far downstream (many times the entry length). The separated flow and vortex system behind the blockage are sensitive to the flow rate. The relevance of these findings to the arterial pulse wave diagnosis methods used in the traditional Chinese medicine is discussed. We show that the human arteries are shorter than the entry length, hence nonaxisymmetric disturbances can be propagated throughout the circulation system. We propose that the propagation of the persistent, small, wavy asymmetric wave is relevant to the “localization” of the spheres of influence of internal and external organs in a two-inch region of the radial artery. We propose further that the method of pressing hard on the artery to “feel” the pulse is to amplify the signal by creating a wake that is very sensitive to velocity of flow.

scholarly journals Methodological assessment of skin and limb blood flows in the human forearm during thermal and baroreceptor provocations

2010 ◽  
Vol 109 (3) ◽  
pp. 895-900 ◽  
Author(s):  
R. Matthew Brothers ◽  
Jonathan E. Wingo ◽  
Kimberly A. Hubing ◽  
Craig G. Crandall
Keyword(s):  
Blood Flow ◽  
Heat Stress ◽  
Doppler Ultrasound ◽  
Skin Blood Flow ◽  
Skin Surface ◽  
Laser Doppler ◽  
Whole Body ◽  
Surface Cooling ◽  
Doppler Flowmetry ◽  
Human Forearm

Skin blood flow responses in the human forearm, assessed by three commonly used technologies—single-point laser-Doppler flowmetry, integrated laser-Doppler flowmetry, and laser-Doppler imaging—were compared in eight subjects during normothermic baseline, acute skin-surface cooling, and whole body heat stress (Δ internal temperature = 1.0 ± 0.2°C; P < 0.001). In addition, while normothermic and heat stressed, subjects were exposed to 30-mmHg lower-body negative pressure (LBNP). Skin blood flow was normalized to the maximum value obtained at each site during local heating to 42°C for at least 30 min. Furthermore, comparisons of forearm blood flow (FBF) measures obtained using venous occlusion plethysmography and Doppler ultrasound were made during the aforementioned perturbations. Relative to normothermic baseline, skin blood flow decreased during normothermia + LBNP ( P < 0.05) and skin-surface cooling ( P < 0.01) and increased during whole body heating ( P < 0.001). Subsequent LBNP during whole body heating significantly decreased skin blood flow relative to control heat stress ( P < 0.05). Importantly, for each of the aforementioned conditions, skin blood flow was similar between the three measurement devices (main effect of device: P > 0.05 for all conditions). Similarly, no differences were identified across all perturbations between FBF measures using plethysmography and Doppler ultrasound ( P > 0.05 for all perturbations). These data indicate that when normalized to maximum, assessment of skin blood flow in response to vasoconstrictor and dilator perturbations are similar regardless of methodology. Likewise, FBF responses to these perturbations are similar between two commonly used methodologies of limb blood flow assessment.

Cutaneous laser-Doppler flowmetry: influence of underlying muscle blood flow

1988 ◽  
Vol 65 (1) ◽  
pp. 478-481 ◽  
Author(s):  
J. L. Saumet ◽  
D. L. Kellogg ◽  
W. F. Taylor ◽  
J. M. Johnson
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Laser Doppler Flowmetry ◽  
Muscle Blood Flow ◽  
Ventral Surface ◽  
Skin Surface ◽  
Laser Doppler ◽  
Doppler Flowmetry ◽  
Forearm Exercise ◽  
Opening And Closing

To find whether the measurement of skin blood flow (SkBF) by laser-Doppler flowmetry (LDF) is influenced by blood flow to underlying skeletal muscle, five subjects performed mild forearm exercise to induce a metabolic hyperemia in muscle in both forearms. This exercise consisted of alternative opening and closing of both hands at a frequency of approximately 1/s for a duration of 3 min. This exercise was performed twice by each subject. Forearm blood flow (FBF) by plethysmography increased from 2.64 +/- 0.49 (rest) to 31.11 +/- 9.95 ml.100 ml-1.min-1 (immediately after exercise) (P less than 0.001). No statistically significant postexercise increase was observed in LDF measured on the dorsal (110 +/- 21 to 105 +/- 21 mV) or ventral surface (266 +/- 113 to 246 +/- 77 mV) of the forearm. LDF measured from the chest also showed no significant change, indicating that the exercise was too mild to have reflex effects on SkBF. Moreover, the slope of the logarithmic linear regression and the half-time for recovery during the postexercise period for FBF were not reflected in LDF measurements from any of the three sites. We conclude that LDF measured from the skin surface is not influenced by blood flow to underlying skeletal muscle.

Beat-to-beat and spectral analyses of the noninvasive radial pulse and laser-Doppler signals in patients with hypertension

2021 ◽  
pp. 1-15
Author(s):  
Ju-Chi Liu ◽  
Yi-Ping Hsu ◽  
Jia-Cheng Zhu ◽  
Wen-Rui Hao ◽  
Tsung-Yeh Yang ◽  
...  
Keyword(s):  
Blood Flow ◽  
Harmonic Component ◽  
Skin Surface ◽  
Relative Energy ◽  
Laser Doppler ◽  
Control Group ◽  
Noninvasive Methods ◽  
Spectral Analyses ◽  
Doppler Flowmetry ◽  
Flow Perfusion

This study performed beat-to-beat and spectral analyses of 20-minute skin-surface laser-Doppler-flowmetry (LDF) and radial blood-pressure-waveform (BPW) signals in order to compare the blood-flow perfusion condition and regulatory mechanisms between essential-hypertension (EHT) patients and aged-matched control subjects. Beat-to-beat LDF analyses yielded the pulse width (PW), AC-to-DC ratio (AD), and their corresponding variability indices (coefficients of variation [CVs]). The relative energy contributions (RECs) of five characteristic frequency peaks (defined as FR1–FR5) were also calculated. Spectral BPW analysis obtained the amplitude proportion (C n ) and phase angle (P n ) of each harmonic component n. PW, AD, AD_CV, and REC of FR2 were significantly smaller in the EHT group than in the control group. Regarding BPW indices, C 1, C 2, C 4, and C 5 were significantly larger and P 2–P 8 were significantly smaller in EHT patients than in controls. The present results indicate that BPW and LDF indices can be used to evaluate the blood-flow perfusion efficiency and microcirculatory regulatory activities in EHT. Sex differences were found, with the effects being more prominent in female patients. These findings may be partly attributable to impairment of endothelial and neural regulatory functions. The present findings might aid the development of new noninvasive methods for reducing the risk of EHT-induced damage.

Peculiarities of microcirculation in periodont tissues in children of key age groups sufficient type 1 diabetes. Part II

2019 ◽  
Vol 24 (2) ◽  
pp. 108-119 ◽  
Author(s):  
B. N. Davydov ◽  
D. A. Domenyuk ◽  
S. V. Dmitrienko
Keyword(s):  
Diabetes Mellitus ◽  
Blood Flow ◽  
Type 1 Diabetes ◽  
Type 1 Diabetes Mellitus ◽  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Diabetic Microangiopathy ◽  
Healthy Children ◽  
Doppler Flowmetry

Relevance. Morpho-functional changes in peripheral circulation established in type 1 diabetes mellitus correlate with changes in central hemodynamics, allowing the use of microcirculation indicators as diagnostic and prognostic criteria for assessing the degree of functional vascular disorders. Identifcation of microcirculation features of the blood by the method of laser Doppler flowmetry in children with different experience of type 1 diabetes in key age categories.Materials and methods. The study included 67 children with type 1 diabetes mellitus aged 12-15 years with an experience of the disease from six months to ten years. The comparison group consisted of 38 healthy children. The state of the microvasculature was assessed by laser Doppler flowmetry using a laser analyzer for capillary blood flow LAKK-OP.Results. In children with an experience of type 1 diabetes of less than two years, microcirculation disorders in periodontal tissues correspond to the hyperemic form, accompanied by increased perfusion, a decrease in the amplitude of low-frequency oscillations, increased heart rate, high blood flling, and blood flow bypass. For children with an endocrinopathy experience of more than three years, microcirculation disorders correspond to a stagnant form, combined with a decrease in perfusion due to stagnation of blood in the venular link, endothelial domination with suppression of neurogenic and cardiac fluctuations, low efciency and redistribution of blood flow in favor of the nutritive link.Conclusions. With the increase in experience, the degree of compensation of type 1 diabetes, the progression of diabetic microangiopathy, it is advisable to designate two stages of development of microcirculatory disorders. Early – compensatory with active adaptation, including neurogenic and endothelial regulation mechanisms. Late – decompensation with passive adaptation, supporting the effectiveness of microcirculation due to myogenic control of regulation, shunting and increasing the rate of blood outflow.

Cardiac-Related Sympathetic Nerve Activity during Circulation with Only the Left Ventricular Assist Device

1992 ◽  
Vol 15 (1) ◽  
pp. 49-54 ◽  
Author(s):  
T. Yambe ◽  
S. Nitta ◽  
Y. Katahira ◽  
T. Sonobe ◽  
S. Naganuma ◽  
...  
Keyword(s):  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Pulse Wave ◽  
Left Ventricular ◽  
Arterial Pulse ◽  
Assist Device ◽  
Ventricular Assist ◽  
Arterial Pulse Wave ◽  
Left Ventricular Assist ◽  
Renal Sympathetic

Circulatory maintenance with a left ventricular assist device (LVAD) alone during cardiac arrest until heart transplantation has been evaluated. To assess the effect on the autonomic nervous system, the sympathetic neurogram was analyzed by power spectrum and coherence function. LVAD were inserted between the left atrium and the descending aorta in seven adult mongrel dogs and ventricular fibrillation was induced electrically. Renal sympathetic nerve activity (RSNA) was detected by bipolar electrodes attached to the left renal sympathetic nerve. Values of squared coherence between the arterial pulse wave and RSNA were calculated. Under the condition of circulatory maintenance with only LVAD, coherence at the cardiac rhythm frequency was decreased, and coherence at the LVAD pumping rhythm frequency was increased. These results indicate that the arterial pulse wave observed during maintenance of the circulation with only LVAD contributed to the sympathetic neurogram.

scholarly journals Laser Doppler blood flowmeter as a useful instrument for the early detection of lower extremity peripheral arterial disease in hemodialysis patients: an observational study

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Takeo Ishii ◽  
Shizuka Takabe ◽  
Yuki Yanagawa ◽  
Yuko Ohshima ◽  
Yasuhiro Kagawa ◽  
...  
Keyword(s):  
Blood Flow ◽  
Peripheral Arterial Disease ◽  
Early Stage ◽  
Arterial Disease ◽  
Hemodialysis Patients ◽  
Laser Doppler ◽  
Doppler Flowmetry ◽  
Skin Perfusion ◽  
Dorsal Area ◽  
Peripheral Arterial

Abstract Background A simpler method for detecting atherosclerosis obliterans is required in the clinical setting. Laser Doppler flowmetry (LDF) is easy to perform and can accurately detect deterioration in skin perfusion. We performed LDF for hemodialysis patients to determine the correlations between blood flow in the lower limbs and peripheral arterial disease (PAD). Methods This retrospective study included 128 hemodialysis patients. Patients were categorized into the non-PAD group (n = 106) and PAD group (n = 22), 14 early stage PAD patients were included in the PAD group. We conducted LDF for the plantar area and dorsal area of the foot and examined skin perfusion pressure (SPP) during dialysis. Results SPP-Dorsal Area values were 82.1 ± 22.0 mmHg in the non-PAD, and 59.1 ± 20.3 mmHg in PAD group, respectively (p < 0.05). The LDF-Plantar blood flow (Qb) values were 32.7 ± 15.5 mL/min in non-PAD group and 21.5 ± 11.3 mL/min in PAD group (p < 0.001). A total of 21 non-PAD patients underwent LDF before and during dialysis. The LDF-Plantar-Qb values were 36.5 ± 17.6 mL/min before dialysis and 29.6 ± 17.7 mL/min after dialysis (p < 0.05). We adjusted SPP and LDF for PAD using logistic regression, SPP-Dorsal-Area and LDF-P were significantly correlated with PAD (p < 0.05). The receiver-operating characteristic curve analysis indicated cut-off values of 20.0 mL/min for LDF-Plantar-Qb during dialysis. Conclusion LDF is a simple technique for sensitive detection of early-stage PAD. This assessment will help physicians identify early-stage PAD, including Fontaine stage II in clinical practice, thereby allowing prompt treatment.

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