ABSTRACT Current computerized pulse diagnosis is mainly based on pressure and photoelectric signal. Considering the richness and complication of pulse diagnosis information, it is valuable to explore the feasibility o...ABSTRACT Current computerized pulse diagnosis is mainly based on pressure and photoelectric signal. Considering the richness and complication of pulse diagnosis information, it is valuable to explore the feasibility of novel types of signal and to develop appropriate feature representation for diagnosis. In this paper, we present a study on computerized pulse diagnosis based on blood flow velocity signal. First, the blood flow velocity signal is collected using Doppler ultrasound device and preprocessed. Then, by locating the fiducial points, we extract the spatial features of blood flow velocity signal, and further present a Hilbert-Huang transform-based method for spectrum feature extraction. Finally, support vector machine is applied for computerized pulse diagnosis. Experiment results show that the proposed method is effective and promising in distinguishing healthy people from patients with cho- lecystitis or nephritis.展开更多
Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury...Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury remain poorly understood. This study sought to observe changes in cerebral blood flow in different regions after mild traumatic brain injury using pulsed arterial spin labeling. Our results demonstrate maximal cerebral blood flow in gray matter and minimal in the white matter of patients with mild traumatic brain injury. At the acute and subacute stages, cerebral blood flow was reduced in the occipital lobe, parietal lobe, central region, subcutaneous region, and frontal lobe. Cerebral blood flow was restored at the chronic stage. At the acute, subacute, and chronic stages, changes in cerebral blood flow were not apparent in the insula. Cerebral blood flow in the temporal lobe and limbic lobe diminished at the acute and subacute stages, but was restored at the chronic stage. These findings suggest that pulsed arterial spin labeling can precisely measure cerebral blood flow in various brain regions, and may play a reference role in evaluating a patient's condition and judging prognosis after traumatic brain injury.展开更多
Background : Information obtained from arterial pulse waveforms (APW) can be usefulfor characterizing the cardiovascular system. To achieve this, it is necessary to know thedetailed characteristics of APWs in differen...Background : Information obtained from arterial pulse waveforms (APW) can be usefulfor characterizing the cardiovascular system. To achieve this, it is necessary to know thedetailed characteristics of APWs in different states of an organism, which would allowAPW parameters (APW- Ps) to be assigned to particular (patho)physiological conditions.Therefore, our work aimed to characterize 35 APW- Ps in rats under the influence ofisoflurane (ISO) and Zoletil/xylazine (ZO/XY) anesthesia and to study the effect of rootextract from Acanthopanax senticosus (ASRE) in these anesthetic conditions.Methods : The right jugular vein of anesthetized rats was cannulated for the administrationof ASRE and the left carotid artery for the detection of APWs from which 35APW- Ps were evaluated.Results : We obtained data on 35 APW- Ps, which significantly depended on the anesthesia,and thus, they characterized the cardiovascular system under these two conditions.ASRE transiently modulated all 35 APW- Ps, including a transient decrease insystolic and diastolic blood pressure (BP) and heart rate or increases in pulse BP, d P /d t max , and systolic and diastolic areas. Whereas the transient effects of ASRE weresimilar, the extract had prolonged disturbing effects on the cardiovascular system inrats under ZO/XY but not under ISO anesthesia. This negative effect can result fromthe disturbance caused by ZO/XY anesthesia on the cardiovascular system.Conclusions : We characterized 35 APW- Ps of rats under ISO and ZO/XY anesthesiaand found that ASRE contains compounds that can modulate the properties of thecardiovascular system, which significantly depended on the status of the cardiovascularsystem. This should be considered when using ASRE as a nutritional supplementby individuals with cardiovascular problems.展开更多
Numerous pathophysiologic observations in humans and animals led to the formulation of the response-to-injury hypothesis of atherosclerosis, which proposed that endothelial denu- dation by the blood flow was the first...Numerous pathophysiologic observations in humans and animals led to the formulation of the response-to-injury hypothesis of atherosclerosis, which proposed that endothelial denu- dation by the blood flow was the first step in atherosclerosis. At present it is impossible to describe hemodynamics only by the Navier-Stokes or Oldroyd-B equations because in the large arteries blood flow is unsteady, with the flow separation and waveform propagation of the thyxotropic mass. The purpose of this paper is to study the impact of the arterial pulse wave on the blood flow and initial factors of atherosclerosis. In 12 healthy men (25-39 years of age) peak velocity, mean velocity, mean flow and net flow in the aorta have been investigated by МR angiography. Initial velocity was registered after 43msec of the ECG-R wave, and it differed from zero at all sites of the aorta, although net flow was equal to zero. Womersley’s number from the ascending to the thoracic aorta decreased from 12.5 ±1.5 to 7.3 ±1.2;flow modified from inertio-elastic to viscous. In the aortic arch in protodiastole blood flow separated into the opposite directed streams resulting in wave superposition with the high net flow. At the isthmus area separated waves interferences and reflects to anterograde direction. Here flow acceleration in protodiastole is 6 times higher than in systole. Pulse waves move on artery walls fifteen or more times more rapidly than the blood flow. Pulse oscillation increases strain rate to the contiguous vessel wall flow layers. At the sites with the flow wave negative interference vessel pulse oscillation attenuates and at the boundary reflection flow wave can shift the vessel wall.展开更多
A noninvasive method for monitoring blood pressure, based on the principles established by Riva-Rocci and Korotkoff (K), is described;it furnishes, after a single compression-deflation cycle of the arm-encircling cuff...A noninvasive method for monitoring blood pressure, based on the principles established by Riva-Rocci and Korotkoff (K), is described;it furnishes, after a single compression-deflation cycle of the arm-encircling cuff, values of sys-tolic and diastolic blood pressures as well as the contours of the brachial arterial pulse and the corresponding volume pulse. K-sounds are detected by a single microphone situated in the cubital fossa, and the time-varying cuff pressure P(t) is read by a piezoresistive pressure sensor. The behavior of P(t) during deflation is resolved into two parts, P(t)=p(t)+b(t);p is a train of posi-tive going pulses (arising from arterial pulsa-tions), whereas b is a slowly changing baseline. Noise pulses in the microphone output are re-jected by using the observation that the first few K-sounds are emitted when p is close to a maxi-mum, and the last few when dp/dt is close to a maximum. The performance of the instrument is illustrated by showing how it copes with ambi-ent noise and involuntary manual perturbations of P, and by presenting contours of various pulses.展开更多
Objective To study the effect of electromagnetic pulse (EMP) exposure on permeability of in vitro blood-brain-barrier (BBB) model. Methods An in vitro BBB model, established by co-culturing brain microvascular end...Objective To study the effect of electromagnetic pulse (EMP) exposure on permeability of in vitro blood-brain-barrier (BBB) model. Methods An in vitro BBB model, established by co-culturing brain microvascular endothelial cells (BMVEC) and astroglial cells (AC) isolated from rat brain, was exposed to EMP at 100 kV/m and 400 kV/m, respectively. Permeability of the model was assayed by measuring the transendothelial electrical resistance (TEER) and the horseradish peroxidase (HRP) transmission at different time points. Levels of BBB tight junction-related proteins were measured at O, 1, 2, 4, 8, 12, 16, 20, 24 h after EMP exposure by Western blotting. Results The TEER level was lower in BBB model group than in control group at 12 h after EMP, exposure which returned to its normal level at 24 h. The 24 h recovery process was triphasic and biphasic respectively after EMP exposure at 100 kV/m and 400 kV/m. Following exposure to 400 kV/m EMP, the HRP permeability increased at 1-12 h and returned to its normal level at 24 h. Western blotting showed that the claudin-5 and ZO-1 protein levels were changed after EMP exposure. Conclusion EMP exposure at 100 kV/m and 400 kV/m can increase the permeability of in vitro BBB model and BBB tight junction-related proteins such as ZO-1 and claudin-5 may change EMP-induced BBB permeability.展开更多
Objective To study the effect of electromagnetic pulse (EMP) exposure on the permeability of blood-testicle barrier (BTB) in mice. Methods Adult male BALB/c mice were exposed to EMP at 200 kV/m for 200 pulses with...Objective To study the effect of electromagnetic pulse (EMP) exposure on the permeability of blood-testicle barrier (BTB) in mice. Methods Adult male BALB/c mice were exposed to EMP at 200 kV/m for 200 pulses with 2 seconds interval. The mice were injected with 2% Evans Blue solution through caudal vein at different time points after exposure, and the permeability of BTB was monitored using a fluorescence microscope. The testis sample for the transmission electron microscopy was prepared at 2 h after EMP exposure. The permeability of BTB in mice was observed by using Evans Blue tracer and lanthanum nitrate tracer. Results After exposure, cloudy Evans Blue was found in the testicle convoluted seminiferous tubule of mice. Lanthanum nitrate was observed not only between testicle spermatogonia near seminiferous tubule wall and sertoli cells, but also between sertoli cells and primary spermatocyte or secondary spermatocyte. In contrast, lanthanum nitrate in control group was only found in the testicle sertoli cells between seminiferous tubule and near seminifdrous tubule wall. Conclusion EMP exposure could increase the permeability of BTB in the mice.展开更多
Objective: To study the regulation of blood pulse volume via photoplethysmography (PPG) signal detected from toe, while the lower limb is passively raised in different height positions. Methods: Use a modified non-inv...Objective: To study the regulation of blood pulse volume via photoplethysmography (PPG) signal detected from toe, while the lower limb is passively raised in different height positions. Methods: Use a modified non-invasive PPG technique to detect the blood pulse signal on toe with infrared (IR) photo sensor. A protocol consisting of two postures, i.e., supine and 45° reclining, was designed to conduct laboratory trial in this study. During the period of performing the protocol of these postures, the lower limb was passively raised from the heights of 10 cm to 60 cm randomly and individually with sponge blocks underneath the foot. Results: In the supine posture, the higher the foot was passively raised, the more the blood PPG signal decreased. In the 45° reclining posture, the blood PPG signal increased at the beginning and then decreased in the foot height position from 10 cm to 60 cm. In both postures the normalized AC signal changes significantly while the normalized DC signal changes little. Conclusion: The toe PPG signals can obviously indicate the regulated blood volume change with the designated postural procedures due to the heart level position.展开更多
A slight reduction of blood pressure and heart rate can reduce the risk of developing cardiovascular disease. Maintenance of the respiratory rate within the normal range has also being identified as crucial for a heal...A slight reduction of blood pressure and heart rate can reduce the risk of developing cardiovascular disease. Maintenance of the respiratory rate within the normal range has also being identified as crucial for a healthy heart. Use of Indian and western music have been considered among many preventive programmes for long time in order to risk reduction associated with cardio vascular diseases. Therefore the aim of this study is to describe the effect of Indian classical music on systolic and diastolic blood pressure, pulse rate and respiratory rate in asymptomatic individuals aged 45 to 65 years. Methodology: A community based randomized intervention study was conducted in 252 asymptomatic individuals. The study group (n = 127) listened to a music based on Indian classical system (entire track of 22 minutes). The control group (n = 125) was kept silent for a similar time period. Systolic and diastolic blood pressure, pulse rate and respiratory rate of each study participant were monitored before and after the intervention. Results: Statistically significant reduction in systolic blood pressure (8.53 mmHg), diastolic blood pressure (5.8 mmHg), pulse rate (5.16 breaths per minute) and respiratory rate (2.55 per minute) were observed in the study group after listening to the music (p < 0.01). In the control group, changes observed during the period of intervention were not significant (p > 0.05). The reduction was independent of gender, age, education level, practicing a mind relaxation technique and preferred type of music of the participant. Conclusions: Listening to Indian classical music for about 22 minutes significantly reduced systolic and diastolic blood pressure, pulse rate and respiratory rate of asymptomatic individuals. Hence, music may have a potential benefit in cardio vascular disease preventive programmes.展开更多
Continuous non-invasive blood pressure (BP) measurement can be realized by using pulse transit time (PTT) based on electrocardiogram (ECG) and pulse wave signal. Modulated magnetic signature of blood (MMSB) is a promi...Continuous non-invasive blood pressure (BP) measurement can be realized by using pulse transit time (PTT) based on electrocardiogram (ECG) and pulse wave signal. Modulated magnetic signature of blood (MMSB) is a promising approach to obtain PTT. The origin of MMSB is critical to establish the relationship between MMSB and BP. In this paper, two possible origins of MMSB, blood disturbance mechanism and angular variation mechanism, are analyzed and verified through three control experi-ments under different conditions. The influence of blood velocity alteration and blood volume alteration on magnetic field is investigated though blood flow simulation sys-tem. It is found that MMSB comes mainly from the periodic blood flow while the per-turbation caused by angular variation between sensitive axis of the magnetic sensor and geomagnetic field can be neglected. As to blood disturbance mechanism, the change of blood volume plays a decisive role while the effect of blood velocity altera-tion is negligible.展开更多
Objective To compare the effect of chemomechanical caries removal(CMCR)to traditional drilling(TD)on blood pressure and pulse in children.Methods Of all 105 subjects,53 were randomly assigned to CMCR group;52,to TD gr...Objective To compare the effect of chemomechanical caries removal(CMCR)to traditional drilling(TD)on blood pressure and pulse in children.Methods Of all 105 subjects,53 were randomly assigned to CMCR group;52,to TD group.For each subject,the systolic pressure(SP),diastolic pressure(DP)and pulse(P)were measured at five time-point:pre-treatment,initiation of carious removal,the end of carious removal,the end of the cavity restoration,and the end of the dental care.They were recorded as T0,T1,T2,T3,and TE,respectively.The difference of SP,DP,and P within each group were analyzed.Results Of all 105 subjects,14 were administered local anesthesia.Since local anesthesia may be a confounding factor for changes in blood pressure and pulse,only the data of the other 91 subjects that local anesthesia were not administered were analyzed.Regarding the SP,DP,and P for TD,the difference between T0 and T1 was significant(P=0.013,0.015,0.012 respectively),while not significant between T1 and T2,T2 and T3,T3 and TE(P>0.05).Regarding the SP,DP,and P for CMCR,the differences were not significant between every two consecutive time-points(P>0.05).The differences of the SP,DP,and P between CMCR and TD were not significant for time-points T0,T3 and TE(p>0.05),while significant for T1 and T2(P<0.05).Conclusion In general,CMCR induces less increase of blood pressure and pulse in children compared to traditional drilling(TD).It may be inferred that CMCR is less distressing than TD.展开更多
Background Pulse wave velocity(PWV) is a marker of arterial stiffness, which represents sub-clinical atherosclerosis. Pulsatile stress and high-sensitivity C-reactive protein(hs-CRP) are associated with arterioscleros...Background Pulse wave velocity(PWV) is a marker of arterial stiffness, which represents sub-clinical atherosclerosis. Pulsatile stress and high-sensitivity C-reactive protein(hs-CRP) are associated with arteriosclerosis. However, there is no prospective data confirming whether changes in pulsatile stress and inflammatory markers affect the progression of arterial stiffness. The aim of this study was to investigate the relationships over time between the effects of changes in pulsatile stress and hs-CRP, and arterial stiffness progression during a 2-year follow-up. Methods We performed a longitudinal study involving 3978 participants. All participants underwent a physical examination in 2010–2011 and 2012–2013, during which we measured participants’ hs-CRP levels, brachial–ankle pulse wave velocity(ba PWV), and pulsatile stress. Results Baseline hs-CRP was correlated with ba PWV(r = 0.18, P = 0.000);however the correlation was weaker than that with systolic blood pressure(r = 0.65), pulsatile stress(r = 0.57), and rate-pressure product(r = 0.58). Multiple linear regression analysis demonstrated that changes in pulsatile stress, mean arterial pressure, and low-density lipoprotein-C(LDL-C) were positively correlated with changes in ba PWV, with correlation coefficients of 0.27, 0.25, and 0.07, respectively, but not with changes in hs-CRP. Moreover, each 100-a U increase in pulsatile stress, 1 mm Hg increase in mean blood pressure, and 1 mmol/L increase in LDL-C was associated with a 3 cm/s, 4.78 cm/s, and 17.37 cm/s increase in ba PWV, respectively. Conclusions Pulsatile stress increases are associated with arterial stiffness progression, but that changes in hs-CRP had no effect on arterial stiffness progression. Hs-CRP may simply be a marker of inflammation in arterial stiffness and has no association with arterial stiffness progression.展开更多
Based upon the blood vessel of being regarded as the elasticity tube, and that the tissue restricts the blood vessel wall, the rule of pulse wave propagation in blood vessel was studied. The viscosity of blood, the el...Based upon the blood vessel of being regarded as the elasticity tube, and that the tissue restricts the blood vessel wall, the rule of pulse wave propagation in blood vessel was studied. The viscosity of blood, the elastic modulus of blood vessel, the radius of tube that influenced the pulse wave propagation were analyzed. Comparing the result that considered the viscosity of blood with another result that did not consider the viscosity of blood, we finally discover that the viscosity of blood that influences the pulse wave propagation can not be neglected; and with the accretion of the elastic modulus the speed of propagation augments and the press value of blood stream heightens; when diameter of blood vessel reduces, the press of blood stream also heightens and the speed of pulse wave also augments. These results will contribute to making use of the information of pulse wave to analyse and auxiliarily diagnose some causes of human disease.展开更多
Blood flow in artery was treated as the flow under equilibrium state (the steady flow under mean pressure)combined with the periodically small pulsatile flow.Using vascular strain energy function advanced by Fung,the ...Blood flow in artery was treated as the flow under equilibrium state (the steady flow under mean pressure)combined with the periodically small pulsatile flow.Using vascular strain energy function advanced by Fung,the vascular stress_strain relationship under equilibrium state was analyzed and the circumferential and axial elastic moduli were deduced that are expressed while the arterial strains around the equilibrium state are relatively small, so that the equations of vessel wall motion under the pulsatile pressure could be established here.Through solving both the vessel equations and the linear Navier_Stokes equations,the analytic expressions of the blood flow velocities and the vascular displacements were obtained.The influence of the difference between vascular circumferential and axial elasticities on pulsatile blood flow and vascular motion was discussed in details.展开更多
Adequate oxygen in red blood cells carrying through the body to the heart and brain is important to maintain life.For those patients requiring blood,blood transfusion is a common procedure in which donated blood or bl...Adequate oxygen in red blood cells carrying through the body to the heart and brain is important to maintain life.For those patients requiring blood,blood transfusion is a common procedure in which donated blood or blood components are given through an intravenous line.However,detecting the need for blood transfusion is time-consuming and sometimes not easily diagnosed,such as internal bleeding.This study considered physiological signals such as electrocardiogram(ECG),photoplethysmogram(PPG),blood pressure,oxygen saturation(SpO2),and respiration,and proposed the machine learning model to detect the need for blood transfusion accurately.For the model,this study extracted 14 features from the physiological signals and used an ensemble approach combining extreme gradient boosting and random forest.The model was evaluated by a stratified five-fold crossvalidation:the detection accuracy and area under the receiver operating characteristics were 92.7%and 0.977,respectively.展开更多
文摘ABSTRACT Current computerized pulse diagnosis is mainly based on pressure and photoelectric signal. Considering the richness and complication of pulse diagnosis information, it is valuable to explore the feasibility of novel types of signal and to develop appropriate feature representation for diagnosis. In this paper, we present a study on computerized pulse diagnosis based on blood flow velocity signal. First, the blood flow velocity signal is collected using Doppler ultrasound device and preprocessed. Then, by locating the fiducial points, we extract the spatial features of blood flow velocity signal, and further present a Hilbert-Huang transform-based method for spectrum feature extraction. Finally, support vector machine is applied for computerized pulse diagnosis. Experiment results show that the proposed method is effective and promising in distinguishing healthy people from patients with cho- lecystitis or nephritis.
文摘Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury remain poorly understood. This study sought to observe changes in cerebral blood flow in different regions after mild traumatic brain injury using pulsed arterial spin labeling. Our results demonstrate maximal cerebral blood flow in gray matter and minimal in the white matter of patients with mild traumatic brain injury. At the acute and subacute stages, cerebral blood flow was reduced in the occipital lobe, parietal lobe, central region, subcutaneous region, and frontal lobe. Cerebral blood flow was restored at the chronic stage. At the acute, subacute, and chronic stages, changes in cerebral blood flow were not apparent in the insula. Cerebral blood flow in the temporal lobe and limbic lobe diminished at the acute and subacute stages, but was restored at the chronic stage. These findings suggest that pulsed arterial spin labeling can precisely measure cerebral blood flow in various brain regions, and may play a reference role in evaluating a patient's condition and judging prognosis after traumatic brain injury.
基金Agency of the Slovak Republic,Grant/Award Number:2/0023/22,2/0066/23 and 2/0091/21Slovak Research&Development Agency,Grant/Award Number:APVV-19-0154 and APVV-22-0154。
文摘Background : Information obtained from arterial pulse waveforms (APW) can be usefulfor characterizing the cardiovascular system. To achieve this, it is necessary to know thedetailed characteristics of APWs in different states of an organism, which would allowAPW parameters (APW- Ps) to be assigned to particular (patho)physiological conditions.Therefore, our work aimed to characterize 35 APW- Ps in rats under the influence ofisoflurane (ISO) and Zoletil/xylazine (ZO/XY) anesthesia and to study the effect of rootextract from Acanthopanax senticosus (ASRE) in these anesthetic conditions.Methods : The right jugular vein of anesthetized rats was cannulated for the administrationof ASRE and the left carotid artery for the detection of APWs from which 35APW- Ps were evaluated.Results : We obtained data on 35 APW- Ps, which significantly depended on the anesthesia,and thus, they characterized the cardiovascular system under these two conditions.ASRE transiently modulated all 35 APW- Ps, including a transient decrease insystolic and diastolic blood pressure (BP) and heart rate or increases in pulse BP, d P /d t max , and systolic and diastolic areas. Whereas the transient effects of ASRE weresimilar, the extract had prolonged disturbing effects on the cardiovascular system inrats under ZO/XY but not under ISO anesthesia. This negative effect can result fromthe disturbance caused by ZO/XY anesthesia on the cardiovascular system.Conclusions : We characterized 35 APW- Ps of rats under ISO and ZO/XY anesthesiaand found that ASRE contains compounds that can modulate the properties of thecardiovascular system, which significantly depended on the status of the cardiovascularsystem. This should be considered when using ASRE as a nutritional supplementby individuals with cardiovascular problems.
文摘Numerous pathophysiologic observations in humans and animals led to the formulation of the response-to-injury hypothesis of atherosclerosis, which proposed that endothelial denu- dation by the blood flow was the first step in atherosclerosis. At present it is impossible to describe hemodynamics only by the Navier-Stokes or Oldroyd-B equations because in the large arteries blood flow is unsteady, with the flow separation and waveform propagation of the thyxotropic mass. The purpose of this paper is to study the impact of the arterial pulse wave on the blood flow and initial factors of atherosclerosis. In 12 healthy men (25-39 years of age) peak velocity, mean velocity, mean flow and net flow in the aorta have been investigated by МR angiography. Initial velocity was registered after 43msec of the ECG-R wave, and it differed from zero at all sites of the aorta, although net flow was equal to zero. Womersley’s number from the ascending to the thoracic aorta decreased from 12.5 ±1.5 to 7.3 ±1.2;flow modified from inertio-elastic to viscous. In the aortic arch in protodiastole blood flow separated into the opposite directed streams resulting in wave superposition with the high net flow. At the isthmus area separated waves interferences and reflects to anterograde direction. Here flow acceleration in protodiastole is 6 times higher than in systole. Pulse waves move on artery walls fifteen or more times more rapidly than the blood flow. Pulse oscillation increases strain rate to the contiguous vessel wall flow layers. At the sites with the flow wave negative interference vessel pulse oscillation attenuates and at the boundary reflection flow wave can shift the vessel wall.
文摘A noninvasive method for monitoring blood pressure, based on the principles established by Riva-Rocci and Korotkoff (K), is described;it furnishes, after a single compression-deflation cycle of the arm-encircling cuff, values of sys-tolic and diastolic blood pressures as well as the contours of the brachial arterial pulse and the corresponding volume pulse. K-sounds are detected by a single microphone situated in the cubital fossa, and the time-varying cuff pressure P(t) is read by a piezoresistive pressure sensor. The behavior of P(t) during deflation is resolved into two parts, P(t)=p(t)+b(t);p is a train of posi-tive going pulses (arising from arterial pulsa-tions), whereas b is a slowly changing baseline. Noise pulses in the microphone output are re-jected by using the observation that the first few K-sounds are emitted when p is close to a maxi-mum, and the last few when dp/dt is close to a maximum. The performance of the instrument is illustrated by showing how it copes with ambi-ent noise and involuntary manual perturbations of P, and by presenting contours of various pulses.
基金supported by the National Basic Research Program of China(2011CB503704,2011CB503705)National Natural Science Foundation of China (No. 30970670, 60871068)
文摘Objective To study the effect of electromagnetic pulse (EMP) exposure on permeability of in vitro blood-brain-barrier (BBB) model. Methods An in vitro BBB model, established by co-culturing brain microvascular endothelial cells (BMVEC) and astroglial cells (AC) isolated from rat brain, was exposed to EMP at 100 kV/m and 400 kV/m, respectively. Permeability of the model was assayed by measuring the transendothelial electrical resistance (TEER) and the horseradish peroxidase (HRP) transmission at different time points. Levels of BBB tight junction-related proteins were measured at O, 1, 2, 4, 8, 12, 16, 20, 24 h after EMP exposure by Western blotting. Results The TEER level was lower in BBB model group than in control group at 12 h after EMP, exposure which returned to its normal level at 24 h. The 24 h recovery process was triphasic and biphasic respectively after EMP exposure at 100 kV/m and 400 kV/m. Following exposure to 400 kV/m EMP, the HRP permeability increased at 1-12 h and returned to its normal level at 24 h. Western blotting showed that the claudin-5 and ZO-1 protein levels were changed after EMP exposure. Conclusion EMP exposure at 100 kV/m and 400 kV/m can increase the permeability of in vitro BBB model and BBB tight junction-related proteins such as ZO-1 and claudin-5 may change EMP-induced BBB permeability.
基金This research was supported by the Natural Science Foundation of Shaanxi (No. 2007C267)National Natural Science Foundation of China (No. 60601026)National 863 Project (No. 2006 AA0224C3)
文摘Objective To study the effect of electromagnetic pulse (EMP) exposure on the permeability of blood-testicle barrier (BTB) in mice. Methods Adult male BALB/c mice were exposed to EMP at 200 kV/m for 200 pulses with 2 seconds interval. The mice were injected with 2% Evans Blue solution through caudal vein at different time points after exposure, and the permeability of BTB was monitored using a fluorescence microscope. The testis sample for the transmission electron microscopy was prepared at 2 h after EMP exposure. The permeability of BTB in mice was observed by using Evans Blue tracer and lanthanum nitrate tracer. Results After exposure, cloudy Evans Blue was found in the testicle convoluted seminiferous tubule of mice. Lanthanum nitrate was observed not only between testicle spermatogonia near seminiferous tubule wall and sertoli cells, but also between sertoli cells and primary spermatocyte or secondary spermatocyte. In contrast, lanthanum nitrate in control group was only found in the testicle sertoli cells between seminiferous tubule and near seminifdrous tubule wall. Conclusion EMP exposure could increase the permeability of BTB in the mice.
文摘Objective: To study the regulation of blood pulse volume via photoplethysmography (PPG) signal detected from toe, while the lower limb is passively raised in different height positions. Methods: Use a modified non-invasive PPG technique to detect the blood pulse signal on toe with infrared (IR) photo sensor. A protocol consisting of two postures, i.e., supine and 45° reclining, was designed to conduct laboratory trial in this study. During the period of performing the protocol of these postures, the lower limb was passively raised from the heights of 10 cm to 60 cm randomly and individually with sponge blocks underneath the foot. Results: In the supine posture, the higher the foot was passively raised, the more the blood PPG signal decreased. In the 45° reclining posture, the blood PPG signal increased at the beginning and then decreased in the foot height position from 10 cm to 60 cm. In both postures the normalized AC signal changes significantly while the normalized DC signal changes little. Conclusion: The toe PPG signals can obviously indicate the regulated blood volume change with the designated postural procedures due to the heart level position.
文摘A slight reduction of blood pressure and heart rate can reduce the risk of developing cardiovascular disease. Maintenance of the respiratory rate within the normal range has also being identified as crucial for a healthy heart. Use of Indian and western music have been considered among many preventive programmes for long time in order to risk reduction associated with cardio vascular diseases. Therefore the aim of this study is to describe the effect of Indian classical music on systolic and diastolic blood pressure, pulse rate and respiratory rate in asymptomatic individuals aged 45 to 65 years. Methodology: A community based randomized intervention study was conducted in 252 asymptomatic individuals. The study group (n = 127) listened to a music based on Indian classical system (entire track of 22 minutes). The control group (n = 125) was kept silent for a similar time period. Systolic and diastolic blood pressure, pulse rate and respiratory rate of each study participant were monitored before and after the intervention. Results: Statistically significant reduction in systolic blood pressure (8.53 mmHg), diastolic blood pressure (5.8 mmHg), pulse rate (5.16 breaths per minute) and respiratory rate (2.55 per minute) were observed in the study group after listening to the music (p < 0.01). In the control group, changes observed during the period of intervention were not significant (p > 0.05). The reduction was independent of gender, age, education level, practicing a mind relaxation technique and preferred type of music of the participant. Conclusions: Listening to Indian classical music for about 22 minutes significantly reduced systolic and diastolic blood pressure, pulse rate and respiratory rate of asymptomatic individuals. Hence, music may have a potential benefit in cardio vascular disease preventive programmes.
文摘Continuous non-invasive blood pressure (BP) measurement can be realized by using pulse transit time (PTT) based on electrocardiogram (ECG) and pulse wave signal. Modulated magnetic signature of blood (MMSB) is a promising approach to obtain PTT. The origin of MMSB is critical to establish the relationship between MMSB and BP. In this paper, two possible origins of MMSB, blood disturbance mechanism and angular variation mechanism, are analyzed and verified through three control experi-ments under different conditions. The influence of blood velocity alteration and blood volume alteration on magnetic field is investigated though blood flow simulation sys-tem. It is found that MMSB comes mainly from the periodic blood flow while the per-turbation caused by angular variation between sensitive axis of the magnetic sensor and geomagnetic field can be neglected. As to blood disturbance mechanism, the change of blood volume plays a decisive role while the effect of blood velocity altera-tion is negligible.
基金Supported by Science and Technology Commission of Shanghai(074119644,09DZ2272100)Shanghai Leading Academic Discipline Project(S30206)
文摘Objective To compare the effect of chemomechanical caries removal(CMCR)to traditional drilling(TD)on blood pressure and pulse in children.Methods Of all 105 subjects,53 were randomly assigned to CMCR group;52,to TD group.For each subject,the systolic pressure(SP),diastolic pressure(DP)and pulse(P)were measured at five time-point:pre-treatment,initiation of carious removal,the end of carious removal,the end of the cavity restoration,and the end of the dental care.They were recorded as T0,T1,T2,T3,and TE,respectively.The difference of SP,DP,and P within each group were analyzed.Results Of all 105 subjects,14 were administered local anesthesia.Since local anesthesia may be a confounding factor for changes in blood pressure and pulse,only the data of the other 91 subjects that local anesthesia were not administered were analyzed.Regarding the SP,DP,and P for TD,the difference between T0 and T1 was significant(P=0.013,0.015,0.012 respectively),while not significant between T1 and T2,T2 and T3,T3 and TE(P>0.05).Regarding the SP,DP,and P for CMCR,the differences were not significant between every two consecutive time-points(P>0.05).The differences of the SP,DP,and P between CMCR and TD were not significant for time-points T0,T3 and TE(p>0.05),while significant for T1 and T2(P<0.05).Conclusion In general,CMCR induces less increase of blood pressure and pulse in children compared to traditional drilling(TD).It may be inferred that CMCR is less distressing than TD.
基金supported by National Natural Science Foundation of China (No.81570383)the Capital Public Health Cultivation Project (No. Z141100002114029)
文摘Background Pulse wave velocity(PWV) is a marker of arterial stiffness, which represents sub-clinical atherosclerosis. Pulsatile stress and high-sensitivity C-reactive protein(hs-CRP) are associated with arteriosclerosis. However, there is no prospective data confirming whether changes in pulsatile stress and inflammatory markers affect the progression of arterial stiffness. The aim of this study was to investigate the relationships over time between the effects of changes in pulsatile stress and hs-CRP, and arterial stiffness progression during a 2-year follow-up. Methods We performed a longitudinal study involving 3978 participants. All participants underwent a physical examination in 2010–2011 and 2012–2013, during which we measured participants’ hs-CRP levels, brachial–ankle pulse wave velocity(ba PWV), and pulsatile stress. Results Baseline hs-CRP was correlated with ba PWV(r = 0.18, P = 0.000);however the correlation was weaker than that with systolic blood pressure(r = 0.65), pulsatile stress(r = 0.57), and rate-pressure product(r = 0.58). Multiple linear regression analysis demonstrated that changes in pulsatile stress, mean arterial pressure, and low-density lipoprotein-C(LDL-C) were positively correlated with changes in ba PWV, with correlation coefficients of 0.27, 0.25, and 0.07, respectively, but not with changes in hs-CRP. Moreover, each 100-a U increase in pulsatile stress, 1 mm Hg increase in mean blood pressure, and 1 mmol/L increase in LDL-C was associated with a 3 cm/s, 4.78 cm/s, and 17.37 cm/s increase in ba PWV, respectively. Conclusions Pulsatile stress increases are associated with arterial stiffness progression, but that changes in hs-CRP had no effect on arterial stiffness progression. Hs-CRP may simply be a marker of inflammation in arterial stiffness and has no association with arterial stiffness progression.
文摘Based upon the blood vessel of being regarded as the elasticity tube, and that the tissue restricts the blood vessel wall, the rule of pulse wave propagation in blood vessel was studied. The viscosity of blood, the elastic modulus of blood vessel, the radius of tube that influenced the pulse wave propagation were analyzed. Comparing the result that considered the viscosity of blood with another result that did not consider the viscosity of blood, we finally discover that the viscosity of blood that influences the pulse wave propagation can not be neglected; and with the accretion of the elastic modulus the speed of propagation augments and the press value of blood stream heightens; when diameter of blood vessel reduces, the press of blood stream also heightens and the speed of pulse wave also augments. These results will contribute to making use of the information of pulse wave to analyse and auxiliarily diagnose some causes of human disease.
文摘Blood flow in artery was treated as the flow under equilibrium state (the steady flow under mean pressure)combined with the periodically small pulsatile flow.Using vascular strain energy function advanced by Fung,the vascular stress_strain relationship under equilibrium state was analyzed and the circumferential and axial elastic moduli were deduced that are expressed while the arterial strains around the equilibrium state are relatively small, so that the equations of vessel wall motion under the pulsatile pressure could be established here.Through solving both the vessel equations and the linear Navier_Stokes equations,the analytic expressions of the blood flow velocities and the vascular displacements were obtained.The influence of the difference between vascular circumferential and axial elasticities on pulsatile blood flow and vascular motion was discussed in details.
基金This work was supported by the Korea Medical Device Development Fund from the Korean government(the Ministry of Science and ICTMinistry of Trade,Indus-try and Energy+2 种基金Ministry of Health and Welfareand Ministry of Food and Drug Safety)(KMDF_PR_20200901_0095)the Soonchunhyang University Research Fund.
文摘Adequate oxygen in red blood cells carrying through the body to the heart and brain is important to maintain life.For those patients requiring blood,blood transfusion is a common procedure in which donated blood or blood components are given through an intravenous line.However,detecting the need for blood transfusion is time-consuming and sometimes not easily diagnosed,such as internal bleeding.This study considered physiological signals such as electrocardiogram(ECG),photoplethysmogram(PPG),blood pressure,oxygen saturation(SpO2),and respiration,and proposed the machine learning model to detect the need for blood transfusion accurately.For the model,this study extracted 14 features from the physiological signals and used an ensemble approach combining extreme gradient boosting and random forest.The model was evaluated by a stratified five-fold crossvalidation:the detection accuracy and area under the receiver operating characteristics were 92.7%and 0.977,respectively.