In vivo label-free measurement of blood flow velocity symmetry based on dual line scanning third-harmonic generation microscopy excited at the 1700 nm window

Measurement of bloodflow velocity is key to understanding physiology and pathology in vivo.While most measurements are performed at the middle of the blood vessel,little research has been done on characterizing the instantaneous bloodflow velocity distribution.This is mainly due to the lack of measurement technology with high spatial and temporal resolution.Here,we tackle this problem with our recently developed dual-wavelength line-scan third-harmonic generation(THG)imaging technology.Simultaneous acquisition of dual-wavelength THG line-scanning signals enables measurement of bloodflow velocities at two radially symmetric positions in both venules and arterioles in mouse brain in vivo.Our results clearly show that the instantaneous bloodflow velocity is not symmetric under general conditions.

The Effects of Chinese Medicines on Micro-circulation of Nail Folds and Blood Flow Velocity of Limbs in the Patients with Arteriosclerotic Obliteration

The effects of Chinese medicines on micro-circulation and blood flow velocity in arteries of the lower limbs were observed in 33 patients with arteriosclerotic obliteration(ASO).The results showed that the integral values of micro-circulation after treatment were obviously higher than those before treatment (P<0.05 or P<0.01).Blood flow velocity in arteries of the lower limbs determined with the color Doppler ultrasound detecting method after treatment were also obviously higher than those before treatment (P<0.05 or P<0.01).In tbis series of 33 ASO patients,the markedly effective rate was 36.36%,and the total effective rate was 63.64%.The observation indicates that the recipe prescribed according to the principle of supplementing qi and activating blood circulation can effectively improve micro-circulation in ASO patients,and accelerate blood flow in arteries of the lower limbs.

Close Correlations Between Carotid Arterial Mean Blood Flow Velocity,Body Mass Index,and Temperature in Normal Individuals

Objective:Assessing carotid and radial pulses is an essential sphygmology method in traditional Chinese medicine(TCM).It is believed in TCM and by doctors that pulse force is markedly linked with the physiological state of a human,including body mass index(BMI)and temperature.However,comprehensive analysis elucidating these potential correlations remains undetermined.Therefore,this investigation aimed to assess the association of pulse strength with human metabolism.Materials and Methods:The mean blood flow velocity(MBFV)of the carotid artery and pulse force of 122 healthy adults included in this investigation were assessed using ultrasound and manual palpation.Their thermal texture map was also acquired.Results:No substantial variation was observed in the carotid arterial MBFV among normal individuals(P>0.05)regardless of body side and gender.However,young individuals had higher blood velocity than middle-aged individuals(P<0.05).Furthermore,it was identified that MBFV was negatively associated with BMI and torso temperature;however,it was positively linked with hand temperature.Conclusions:This investigation revealed that carotid arterial MBFV could indicate the physical state of humans,including BMI and temperature,and therefore,is valuable for elucidating the effect of TCM on yin–yang.The data validated some TCM beliefs and supported the implementation of sphygmology in TCM.

Compromised cerebrovascular modulation in chronic anxiety:evidence from cerebral blood flow velocity measured by transcranial Doppler sonography

Objective Cerebral autoregulation （CA） is the mechanism by which constant cerebral blood flow is maintained despite changes in cerebral perfusion pressure. CA can be evaluated by dynamic monitoring of cerebral blood flow velocity （CBFV） with transcranial Doppler sonography （TCD）. The present study aimed to explore CA in chronic anxiety. Methods Subjects with Hamilton anxiety scale scores 〉14 were enrolled and the dynamic changes of CBFV in response to an orthostatic challenge were investigated using TCD. Results In both the anxious and the healthy subjects, the mean CBFV was significantly lower in the upright position than when supine. However, the CBFV changes from supine to upright differed between the anxious and the healthy groups. Anxious subjects showed more pronounced decreases in CBFV with abrupt standing. Conclusion Our results indicate that cerebrovascular modulation is compromised in chronic anxiety; anxious subjects have some insufficiency in maintaining cerebral perfusion after postural change. Given the fact that anxiety and impaired CA are associated with cardiovascular disease, early ascertainment of compromised cerebrovascular modulation using TCD might suggest interventional therapies in the anxious population, and improve the primary prevention of cardiovascular disease.

Clinical Significance of Fetal Cerebral and Umbilical Arte-rial Blood Flow Velocity Wave Forms Examination.

Color Doppler was used to examine the blood flow velocity wave forms of fetal middle cerebral artery (MCA) and umbilical artery (UA) in normal pregnancy (58 cases) pregnancy induced hypertension (PIH) with fetal growth retardation (IUGR) (54 cases) and without IUGR (34 cases). The peak-systolic / diastole ratio (S/D), pulse index (PI) and resistance index (RI) values of MCA and UA were calcu-

Effects of acupuncture combined with Brunnstrom staging on upper-limb motor function,cerebral arterial blood flow velocity,and brain function remodeling after stroke

Objective:To explore the effects of acupuncture combined with Brunnstrom staging on upper-limb motor function,cerebral arterial blood flow velocity,and brain function remodeling after stroke.Methods:A total of 77 patients after stroke were selected between January 2017 and December 2019 to perform a prospective study.All cases were divided into an observation group and a control group by the random number table method.Both groups were treated with conventional symptomatic treatment for stroke and functional exercise according to the Brunnstrom staging.The observation group was treated with additional acupuncture treatment based on the Brunnstrom staging therapy.The therapeutic efficacy was evaluated after six-week treatment.The traditional Chinese medicine(TCM)symptom scores of dizziness,headache,limb numbness,and language disorders before and after the treatment in the two groups were compared.According to the Fugl-Meyer motor function assessment(FMA),the upper-limb motor function before and after the treatment was compared.And the average systolic blood flow velocity of the anterior cerebral artery(ACA),middle cerebral artery(MCA),and posterior cerebral artery(PCA)in the two groups before and after the treatment were compared.According to the modified Edinburgh-Scandinavia stroke scale(MESSS),the nerve function before and after the treatment was compared.Results:The total effective rate of the observation group was 94.9%,significantly higher than 79.0%of the control group(P<0.05).After the treatment,the TCM symptom scores of dizziness,headache,limb numbness,and language disorders in both groups decreased,and the scores in the observation group were all significantly lower than those in the control group(P<0.05).The FMA score of upper limbs in both groups increased,and the score in the observation group was significantly higher than that in the control group(P<0.05).The average systolic blood flow velocities of the ACA,MCA and PCA in both groups increased,and were significantly higher in the observation group than in the control group(P<0.05).The MESSS score in both groups decreased,and the score in the observation group was significantly lower than that in the control group(P<0.05).Conclusion:Acupuncture combined with Brunnstrom staging is effective for patients after stroke.It can effectively improve the upper-limb motor function and cerebral artery blood flow velocity,promote brain function remodeling,and restore nerve function.

The inter-visit variability of retinal blood flow velocity measurements using retinal function imager (RFI)

Background:To determine the inter-visit variability of retinal blood flow velocities(BFVs)using a retinal function imager(RFI)in healthy young subjects.Methods:Twenty eyes of 20 healthy young subjects were enrolled.RFI imaging was performed to obtain the BFVs in retinal arterioles and venules in a field measuring 7.3×7.3 mm^(2)(setting:35 degrees)centered on the fovea,and repeated measurements were obtained on two separate days.The inter-visit variability of BFVs was assessed by the concordance correlation coefficient(CCC)and coefficient of variance(CV).Results:At the first visit,the mean BFV was 3.6±0.8 mm/s and 3.0±0.7 mm/s in arterioles and venules,respectively,which were not significantly different from those at the second visit(the BFV of arterioles was 3.5±0.8 mm/s,and the BFV of venules was 3.0±0.7 mm/s,P>0.05,respectively).The CCC was 0.72 in the BFVs of arterioles and 0.67 in venules,and the CV was 10.8%in the BFVs of arterioles and 11.0%in venules.Conclusion:The inter-visit variability using the retinal function imager(RFI)with a large field of view appeared to be good and comparable to previously reported intra-visit and inter-eye variability.

RETINAL SPECTRAL IMAGING AND BLOOD FLOW MEASUREMENT

Measurement of both oxygen saturation and blood flow in the retinal vessels has proved to give important information about the eye health and the onset of eye pathologies such as diabetic retinopathy.In this study,we present the implementation,on a commercially available fundus camera,of a retinal imager and a retina blood flow velocimeter.The retinal imager uses division of aperture to acquire nine wavelength-dependent sub-images of the retina.Careful consideration is taken to improve image transfer by measuring the optical properties of the fundus camera and modeling the optical train in Zemax.This part of the setup is calibrated with optical phantoms of known optical properties that are also used to build a lookup table(LUT)linking phantom optical properties to measured reflectance.The retina blood flow velocimeter relies on tracking clusters of erythrocytes and uses a fast acquisition camera attached to a zoom lens,with a green illumination LED-engine.Calibration is provided using a calibrated quartz capillary tube and human blood at a known flow rate.Optical properties of liquid phantoms are retrieved from measured reflectance using the LUT,and blood flow measurements in the retina are presented.

EFFECTS OF ACUPUNCTURE AT FENGCHI POINT (GB 20) ON CEREBRAL BLOOD FLOW

Blood velocity in the vertebral artery and the basilar artery was observed before and after acupuncture at Fengchi point (GB 20) in 97 patients by transcranial Doppler ultrasonic detecting. The results showed that the blood velocity in patients with either high or low blood flow had significant changes after acupuncture (P

EFFECTS OF ELECTRO ACUPUNCTURE AND TWIRLING REINFORCING-REDUCING MANIPULATIONS ON VOLUME OF MICROCIRCULATORY BLOOD FLOW IN CEREBRAL PIA MATER

Effects of electroacupuncture (EA) and routine acupuncture with twirling reinforcing and reducing manipulation of the needle (RA) both at Zusanli point (St 36) on volume of microcirculatory blood flow in the cerebral pia mater were observed by fenestration of the cranial bone and laser Doppler microcirculatory blood flow analyser. Results showed that both RA and EA could increase the volume of microcirculatory blood flow in the cerebral pia mater; and that the increase in the EA group was superior to that in RA group. This suggests that a moderate and effective stimulation is a key to the production of a regulative effect on the organism.

Effect of swimming training on neural microcirculation in rats with sciatic nerve compression A study based on laser Doppler flowmetry

Microcirculation of the peripheral nerve is necessary for neural growth and regeneration. However, technical limitations have limited studies in this area. The few studies conducted have concerned active exercise effects on microcirculation of the peripheral nerve. Using an animal experiment, this study evaluated the effect of swimming training on microcirculation of injured peripheral nerve by laser Doppler flowmetry. The results showed that the blood vessel at the distal end of the peripheral nerve was the main blood supply for the nerve, and the internal blood supply for the nerve had strong compensatory ability. Swimming training promoted the functional recovery of rats with sciatic nerve injury and the regeneration of myelin sheath and blood vessels, but had no impact on neural blood flow.

Cynodon dactylon andSida acuta extracts impact on the function of the cardiovascular system in zebrafish embryos

The aim of the present study was to screen cardioactive herbs from Western Ghats of India. The heart beat rate （HBR） and blood flow during systole and diastole were tested in zebrafish embryos. We found that Cynodon dactylon （C. dactylon） induced increases in the HBR in zebrafish embryos with a HBR of （3.968±0.344） beats/ s, which was significantly higher than that caused by betamethosone [（3.770±0.344） beats/s]. The EC50 value of C. dactylon was 3.738 μg/mL. The methanolic extract of Sida acuta （S. acuta） led to decreases in the HBR in zebrafish embryos [（1.877 ±0.079） beats/s], which was greater than that caused by nebivolol （positive control）. The EC50 value of Sida acuta was 1.195 μg/mL. The untreated embryos had a HBR of （2.685±0.160） beats/s at 3 d post fertilization （dpf）. The velocities of blood flow during the cardiac cycle were （2,291.667 ±72.169） μm/s for the control, （4,250± 125.000） μm/s for C. dactylon and （1,083.333±72.169） μm/s for S. acuta. The LC50 values were 32.6 μg/mL for C. dactylon and 20.9 μg/mL for S. acuta. In addition, the extracts exhibited no chemical genetic effects in the drug dosage range tested. In conclusion, we developed an assay that can measure changes in cardiac function in response to herbal small molecules and determine the cardiogenic effects by microvideography.

Recent advancement in diagnosis of vasculogenic impotence

Several dynamic tests with vasoactive drags are available for evaluating penile vascular inflows and outflows,ranging from simple pharmacologic test to more invasive radiologic sets. However, there is still no perfect single testto reflect the penile vascular flow. All possible efforts should be exerted to get the greatest erectile effect to avoid anunderestimation of blood flow to the corpora due to incomplete relaxation of the trabecular smooth muscle.Appreciation of the type and frequency of anatomical variations and potential collateral routes is important in interpretingpenile arterograms and in evaluating the hemodynamic significance of suspected arterial disease. Choice of the vasculartests should always depend on the purpose of testing.

Pre-and postoperative changes of regional cortical cerebral blood flow in patients with cerebral arteriovenous malformation

Objective To investigate pre- and postoperative changes of regional cerebral cortical blood flow in patients with cerebral arteriovenous malformation. Method Twenty-two adult patients with arteriovenous malformation(AVM) were recruited into this study at Beijing Tiantan Hospital from September 2001 to May 2002. Eight patients had giant cerebral AVM and the other 14 had a small one. Cortical cerebral blood flow (CBF) was measured by laser Doppler flowmetry (LDF) before and after AVM resections. After surgery,the probe of LDF was implanted adjacent to the area of AVM and monitored for 24 hours.Results CBF increased significantly after the resection in all patients regardless of AVM size. In patients with small AVM,CBF returned to the baseline level within 4 hours,but in patients with giant AVM,CBF remained high even after 24 hours.Conclusions Monitoring CBF is helpful to understand pre- and postoperative changes of regional cortical CBF in patients with cerebral AVM.

Effect of Physical Intervention on Preventing Upper Limb Venous Thrombosis of Patients with PICC: A Systematic Review and Meta-Analysis of Randomized Trials

Objective: To evaluate the effect of physical methods on the prevention of venous thrombosis in patients with peripherally inserted central catheter (PICC). Methods: Randomized controlled trials meeting the inclusion and exclusion criteria were retrieved from the following databases: Cochrane library, Pubmed, EMbase, Web of science, Ovid, CBM, CNKI, Wanfang, VIP, then Review Manage (RevMan) 5.3 software was used for data analysis. Results: A total of 24 RCTs including 3496 patients were analyzed in the study. The results of meta-analysis showed that various forms of upper limb movements could effectively decrease the incidence of venous thrombosis in the patients with PICC [RR = 0.23, 95% CI (0.16, 0.33), P < 0.01], upper limb movements could effectively improve the mean blood flow velocity of basilic vein [MD = 1.65, 95% CI (1.19, 2.11), P < 0.01]. Conclusion: Upper limb movements can effectively decrease the incidence of phlebothrombosis and improve the mean flow velocity of basilic vein in the patients undergoing PICC. Other forms of physical prevention methods need to be further studied due to insufficient sample size.

Left atrial appendage flow velocity in rheumatic mitral stenosis

The left atrial appendage ( LAA ) has been considered a relatively insignificant portion of the cardiac anatomy. Because thrombi have been found to have a predilection to form within the LAA, a better understanding of the LAA is necessary. Transesophageal echocardiography (TEE) is a technique that makes clear imaging of the

Microvascular blood flow velocities measured with a retinal function imager: inter-eye correlations in healthy controls and an exploration in multiple sclerosis

Background:The retinal microcirculation has been studied in various diseases including multiple sclerosis(MS).However,inter-eye correlations and potential differences of the retinal blood flow velocity(BFV)remain largely unstudied but may be important in guiding eye selection as well as the design and interpretation of studies assessing or utilizing retinal BFV.The primary aim of this study was to determine inter-eye correlations in BFVs in healthy controls(HCs).Since prior studies raise the possibility of reduced BFV in MS eyes,a secondary aim was to compare retinal BFVs between MS eyes,grouped based on optic neuritis(ON)history and HC eyes.Methods:Macular arteriole and venule BFVs were determined using a retinal function imager(RFI)in both eyes of 20 HCs.One eye from a total of 38 MS patients comprising 13 eyes with ON(MSON)and 25 eyes without ON(MSNON)history were similarly imaged with RFI.Results:OD(right)and OS(left)BFVs were not significantly different in arterioles(OD:3.95±0.59 mm/s;OS:4.08±0.60 mm/s,P=0.10)or venules(OD:3.11±0.46 mm/s;OS:3.23±0.52 mm/s,P=0.06)in HCs.Very strong inter-eye correlations were also found between arteriolar(r=0.84,P<0.001)and venular(r=0.87,P<0.001)BFVs in HCs.Arteriolar(3.48±0.88 mm/s)and venular(2.75±0.53 mm/s)BFVs in MSNON eyes were significantly lower than in HC eyes(P=0.009 and P=0.005,respectively).Similarly,arteriolar(3.59±0.69 mm/s)and venular(2.80±0.45 mm/s)BFVs in MSON eyes were also significantly lower than in HC eyes(P=0.046 and P=0.048,respectively).Arteriolar and venular BFVs in MSON and MSNON eyes did not differ from each other(P=0.42 and P=0.48,respectively).Conclusions:Inter-eye arteriolar and venular BFVs do not differ significantly in HCs and are strongly correlated.Our findings support prior observations that arteriolar and venular BFVs may be reduced in MS eyes.Moreover,this seems to be the case in both MS eyes with and without a history of ON,raising the possibility of global blood flow alterations in MS.Future larger studies are needed to assess differences in BFVs between MSON and MSNON eyes.

Electrical stimulation of acupoint combinations against deep venous thrombosis in elderly bedridden patients after major surgery

OBJECTIVE:To compare the effects of electrical stimulation of different acupoint combinations among postoperative bedridden elderly patients on hemorheology and deep venous blood flow velocity and investigate the role of electrical stimulation against deep vein thrombosis(DVT).METHODS:From November 2010 to October 2011,a total of 160 elderly bedridden patients after major surgery were divided into the conventional care group,invigorating and promoting Qi group,blood-activating and damp-eliminating group,and acupoint-combination stimulation group.Whole blood viscosity,plasma viscosity,D-dimer levels,lower limb skin temperature,lower limb circumference,and flow velocities of the external iliac vein,femoral vein,popliteal vein,and deep calf veins in all patients were documented and compared among the four groups.RESULTS:Whole blood viscosity,plasma viscosity,D-dimer levels,and lower limb circumference were significantly reduced in the blood-activating and damp-eliminating group compared with the conventional care group(P<0.05) and were almost equal to those in the acupoint-combination stimulation group(P>0.05).Lower limb venous flow velocities were accelerated in the invigorating and promoting Qi group compared with the other groups,excluding the acupoint-combination stimulation group(P<0.05).CONCLUSION:Hemorheological indices in postoperative bedridden elderly patients were improved after combined electrical stimulation at Yinlingquan(SP 9) and Sanyinjiao(SP 6).Combined electrical stimulation at Zusanli(ST 36) and Taichong(LR 3),on the other hand,accelerated lower limb venous flow.

Retinal nerve fiber layer (RNFL) integrity and its relations to retinal microvasculature and microcirculation in myopic eyes

Background:The aim was to determine retinal nerve fiber layer function and its relations to retinal microvasculature and microcirculation in patients with myopia.Method:Polarization-sensitive optical coherence tomography(PS-OCT)was used to measure phase retardation per unit depth(PR/UD,proportional to the birefringence)of the retinal nerve fiber layer(RNFL).Optical coherence tomography angiography(OCTA)was used to measure macular vessel density analyzed using fractal analysis.In addition,a retinal function imager(RFI)was used to measure macular blood flow velocities in arterioles and venules.Twenty-two patients with moderate myopia(MM,refraction>3 and<6 diopters),seventeen patients with high myopia(HM,≥6 D)and 29 healthy control subjects(HC,≤3.00 D)were recruited.One eye of each patient was imaged.Results:Although the average PR/UD of the RNFL in the HM group did not reach a significant level,the birefringence of the inferior quadrant was significantly lower(P<0.05)in the HM group compared to the HC group.Significant thinning of the average RNFL and focal thinning of RFNL in temporal,superior and inferior quadrants in the HM group were found,compared to the HC group(P<0.05).There were no significant differences of retinal blood flow velocities in arterioles and venules among groups(P>0.05).The macular vessel density in both superficial and deep vascular plexuses was significantly lower in the HM group than in the other two groups(P<0.05)as well as in the MM group than in the HC group(P<0.05).The average PR/UD and PR/UD in the inferior quadrant were not related to refraction,axial length,blood flow velocities and macular vessel densities(r ranged from−0.09 to 0.19,P>0.05).Conclusions:The impairment of the retinal nerve fiber birefringence in the HM group may be one of the independent features in high myopic eyes,which appeared not to relate to macular microvascular density and blood flow velocity.

Prognostic value of Doppler transmitral filling patterns in patients with chronic heart failure

Background Chronic heart failure is a significant cause of cardiovascular morbidity and mortality. This study tested the hypothesis that restrictive filling pattern may provide useful prognostic data for identifying patients with chronic heart failure at high risk of all-cause cardiac death.Methods Ninety patients with chronic heart failure [ 70 men and 20 women, mean age (58.1 ± 11.6) years] were investigated and followed for (18. 8 ±7. 9) months. During this period, 14 patients died of progressive pump failure, 12 patients underwent heart transplantation, 5 patients died suddenly, and 2 patients died of acute myocardial infarction. A new criterion, the restrictive filling index (RFI), was designed to subgroup patients into a restrictive and a nonrestrictive group.Results Patients with restrictive filling pattern had a more severe left ventricular dysfunction and a higher cardiac mortality. Analysis by the Kaplan-Meier method revealed that patients in the RFI≥1 and RFI <1 groups had a cardiac events-free survival rate of 52% versus 94% at 1 year, and 27. 5% versus 92% at 2 years, respectively. The multivariate Cox proportional hazard model selected RFI as the most powerful prognostic factor (x2 =8. 8017, P=0. 0030) for all-cause cardiac death.Conclusion These results indicate that RFI is a simple, noninvasive, and specific clinical predictor for adult chronic heart failure patients who are at a high risk for all-cause cardiac death.