scholarly journals Novel Application of a Multiscale Entropy Index as a Sensitive Tool for Detecting Subtle Vascular Abnormalities in the Aged and Diabetic

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Hsien-Tsai Wu ◽  
Men-Tzung Lo ◽  
Guan-Hong Chen ◽  
Cheuk-Kwan Sun ◽  
Jian-Jung Chen
Keyword(s):  
Glycosylated Hemoglobin ◽  
Reactive Hyperemia ◽  
Multiscale Entropy ◽  
Arterial Pulse ◽  
Vascular Changes ◽  
Entropy Index ◽  
Pressure Sensing ◽  
Vascular Abnormalities ◽  
Sensing System ◽  
Sensitive Tool

Although previous studies have shown the successful use of pressure-induced reactive hyperemia as a tool for the assessment of endothelial function, its sensitivity remains questionable. This study aims to investigate the feasibility and sensitivity of a novel multiscale entropy index (MEI) in detecting subtle vascular abnormalities in healthy and diabetic subjects. Basic anthropometric and hemodynamic parameters, serum lipid profiles, and glycosylated hemoglobin levels were recorded. Arterial pulse wave signals were acquired from the wrist with an air pressure sensing system (APSS), followed by MEI and dilatation index (DI) analyses. MEI succeeded in detecting significant differences among the four groups of subjects: healthy young individuals, healthy middle-aged or elderly individuals, well-controlled diabetic individuals, and poorly controlled diabetic individuals. A reduction in multiscale entropy reflected age- and diabetes-related vascular changes and may serve as a more sensitive indicator of subtle vascular abnormalities compared with DI in the setting of diabetes.

scholarly journals LifeChair: A Conductive Fabric Sensor-Based Smart Cushion for Actively Shaping Sitting Posture

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2261 ◽  
Author(s):  
Karlos Ishac ◽  
Kenji Suzuki
Keyword(s):  
Detection Accuracy ◽  
Upright Posture ◽  
Performance Study ◽  
Vibrotactile Feedback ◽  
Pressure Sensing ◽  
Sitting Posture ◽  
Conductive Fabric ◽  
The Past ◽  
Sensing System ◽  
Average Accuracy

The LifeChair is a smart cushion that provides vibrotactile feedback by actively sensing and classifying sitting postures to encourage upright posture and reduce slouching. The key component of the LifeChair is our novel conductive fabric pressure sensing array. Fabric sensors have been explored in the past, but a full sensing solution for embedded real world use has not been proposed. We have designed our system with commercial use in mind, and as a result, it has a high focus on manufacturability, cost-effectiveness and adaptiveness. We demonstrate the performance of our fabric sensing system by installing it into the LifeChair and comparing its posture detection accuracy with our previous study that implemented a conventional flexible printed PCB-sensing system. In this study, it is shown that the LifeChair can detect all 11 postures across 20 participants with an improved average accuracy of 98.1%, and it demonstrates significantly lower variance when interfacing with different users. We also conduct a performance study with 10 participants to evaluate the effectiveness of the LifeChair device in improving upright posture and reducing slouching. Our performance study demonstrates that the LifeChair is effective in encouraging users to sit upright with an increase of 68.1% in time spent seated upright when vibrotactile feedback is activated.

Abnormal vascular function and morphology in preeclampsia: a study of isolated resistance vessels

1985 ◽  
Vol 69 (4) ◽  
pp. 477-482 ◽  
Author(s):  
C. Aalkjaer ◽  
H. Danielsen ◽  
P. Johannesen ◽  
E. B. Pedersen ◽  
A. Rasmussen ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Pregnant Women ◽  
Vascular Function ◽  
Direct Evidence ◽  
The Other ◽  
Vascular Changes ◽  
Direct Information ◽  
Vascular Abnormalities ◽  
Media Thickness ◽  
Resistance Vessels

1. In order to obtain direct information about vascular changes associated with pre-eclampsia, the morphological and functional characteristics of isolated omental resistance vessels from 11 women with pre-eclampsia, 10 normotensive pregnant women and eight normotensive nonpregnant women were determined. 2. In vessels from the women with preeclampsia, the ratio of media thickness to lumen diameter was increased, compared with that in vessels from the other two groups. 3. The vessels from the women with preeclampsia had an increased responsiveness to angiotensin II and a decreased rate of relaxation, but only when compared with the vessels from the normotensive pregnant women. However, no difference in responsiveness to noradrenaline was found between any of the groups. 4. The angiotensin II responsiveness of the vessels from the women with pre-eclampsia and from the non-pregnant women were similar, suggesting that pre-eclampsia is associated with an absence of the change in vascular function which normally occurs during pregnancy. 5. The study provides direct evidence for an involvement of vascular abnormalities in the pathogenesis of pre-eclampsia.

Implementation of Distributed Polarization Maintaining Fiber Polarization Coupling Pressure Sensing System

2010 ◽  
Vol 37 (6) ◽  
pp. 1467-1472 ◽  
Author(s):  
陈信伟 Chen Xinwei ◽  
张红霞 Zhang Hongxia ◽  
贾大功 Jia Dagong ◽  
刘铁根 Liu Tiegen ◽  
张以谟 Zhang Yimo
Keyword(s):  
Pressure Sensing ◽  
Sensing System ◽  
Polarization Maintaining Fiber ◽  
Polarization Maintaining

Combined effect of cigarette smoking and prediabetes on structural and functional changes of large arteries

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
N Ioakeimidis ◽  
I Dima ◽  
D Terentes-Printzios ◽  
C Georgakopoulos ◽  
A Angelis ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Smoking Status ◽  
Structural Parameters ◽  
Glycosylated Hemoglobin ◽  
Fasting Blood Glucose ◽  
Systolic Pressure ◽  
Oral Glucose ◽  
Vascular Changes ◽  
Functional Changes ◽  
Large Arteries

Abstract Purpose Smoking is a major risk factor for cardiovascular disease and prediabetes is associated with excess risks for adverse cardiovascular outcomes and death. Aim of this study was to explore whether smoking and prediabetes exert a synergistic unfavourable effect on functional and structural parameters of large arteries. Methods We measured carotid-femoral pulse wave velocity (cfPWV), augmentation index (AIx) and carotid intima media thickness (cIMT) in 407 individuals without known atherosclerotic disease (mean age: 52±8 years) categorized into four age-matched groups according to glucose metabolic and smoking status: Smokers with diabetes (n=68), Smokers with prediabetes (n=87), Non-smokers with prediabetes (n=98) and Non- smokers with normal fasting blood glucose (FBG) (n=154). Prediabetes was defined as impaired fasting glucose (100–125 mg/dL), impaired glucose tolerance (2-hour glucose level of 140–199 mg/dL during an oral glucose tolerance test), or glycosylated hemoglobin (HbA1c) level of 5.7% to 6.4%. High sensitivity C-reactive protein (hsCRP) was measured in all patients. Results Systolic pressure, pulse pressure were increased and hsCRP levels were higher in smokers with diabetes compared to the three other groups (overall P<0.05, P<0.01 and P<0.05, respectively, ANOVA). The cumulative tobacco exposure (measured in pack-years) was similar between smokers with diabetes and smokers with prediabetes (45 pack-years). Figure 1 shows cfPWV, AIx and cIMT of the four groups. Interestingly, smokers with diabetes and smokers with prediabetes have similar mean cfPWV and cIMT and significantly higher values compared to non-smokers with prediabetes and non-smokers with normal FBG. The associations remained statistically significant even after adjusting for systolic pressure and hsCRP level. AIx was not different between the four study groups. Conclusion The combination of prediabetes and smoking is associated with higher cfPWV and cIMT values compared to prediabetes alone. The smokers with impaired glucose regulation have functional and structural alterations of large arteries similar to that of smokers with established diabetes. Considering the risk for developing prediabetes in relation to smoking status and the number of cigarettes smoked daily and the independent predictive value of assessing vascular changes in large arteries, the present findings may have important clinical and prognostic implications. Figure 1. Smoking, prediabetes and vascular changes Funding Acknowledgement Type of funding source: None

Intralipid effect on normal and hypoxic remodeled rat pulmonary vasculature

1988 ◽  
Vol 255 (6) ◽  
pp. H1499-H1508
Author(s):  
R. Ilkiw ◽  
K. Maruyama ◽  
M. Rabinovitch
Keyword(s):  
Smooth Endoplasmic Reticulum ◽  
Left Lung ◽  
Volume Density ◽  
Pulmonary Vasculature ◽  
Alveolar Wall ◽  
External Diameter ◽  
Vascular Changes ◽  
Sprague Dawley ◽  
Vascular Abnormalities ◽  
Pentobarbital Sodium Anesthesia

Intralipid (IL) infusion has been associated with pulmonary vasoconstriction and decreased oxygenation and may worsen preexisting pulmonary vascular changes. To investigate this, we infused IL or 0.9% saline for 1 wk in normal Sprague-Dawley rats and in rats with vascular changes induced by a previous 2-wk exposure to chronic hypobaric hypoxia (air at 380 mmHg). At postmortem we quantitatively evaluated arterial changes in the left lung by light microscopy and alterations in endothelial cells in the right lung by electron microscopy. In rats maintained in room air, 1-wk IL infusion resulted in extension of muscle into alveolar wall and duct arteries (P less than 0.001 for both), medial hypertrophy of arteries 50–99 microns external diameter (P less than 0.01), reduced arterial density (P less than 0.05), and an increase in volume density of endothelial smooth endoplasmic reticulum (P less than 0.05). In post-hypoxia rats, however, IL infusion did not induce further progression of the more severe arterial and endothelial changes observed. To determine whether IL-associated vascular abnormalities may be related to vasoconstriction, different rats were instrumented under pentobarbital sodium anesthesia with indwelling cardiovascular catheters and, 2 days later, with the animals fully conscious, the hemodynamic response assessed. An acute 15-min IL infusion caused a significant increase in pulmonary artery pressure and mild hypoxemia (P less than 0.05 for both) in room air rats but not in the posthypoxia group. This response was not, however, sustained over a 2-day IL infusion. Thus IL induces pulmonary vascular abnormalities that do not appear to be related to vasoconstriction or hypoxemia. We speculate that differences in endothelial metabolism of IL in room air and posthypoxia rats may explain the lack of IL-related abnormalities in the latter group.

scholarly journals Using Multiscale Entropy to Assess the Efficacy of Local Cooling on Reactive Hyperemia in People with a Spinal Cord Injury

Entropy ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 90 ◽  
Author(s):  
Fuyuan Liao ◽  
Tim Yang ◽  
Fu-Lien Wu ◽  
Chunmei Cao ◽  
Ayman Mohamed ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Blood Flow ◽  
Temperature Change ◽  
Pressure Ulcers ◽  
Reactive Hyperemia ◽  
Multiscale Entropy ◽  
Intervention Period ◽  
Local Cooling ◽  
Cord Injury

Pressure ulcers are one of the most common complications of a spinal cord injury (SCI). Prolonged unrelieved pressure is thought to be the primary causative factor resulting in tissue ischemia and eventually pressure ulcers. Previous studies suggested that local cooling reduces skin ischemia of the compressed soft tissues based on smaller hyperemic responses. However, the effect of local cooling on nonlinear properties of skin blood flow (SBF) during hyperemia is unknown. In this study, 10 wheelchair users with SCI and 10 able-bodied (AB) controls underwent three experimental protocols, each of which included a 10-min period as baseline, a 20-min intervention period, and a 20-min period for recovering SBF. SBF was measured using a laser Doppler flowmetry. During the intervention period, a pressure of 60 mmHg was applied to the sacral skin, while three skin temperature settings were tested, including no temperature change, a decrease by 10 °C, and an increase by 10 °C, respectively. A multiscale entropy (MSE) method was employed to quantify the degree of regularity of blood flow oscillations (BFO) associated with the SBF control mechanisms during baseline and reactive hyperemia. The results showed that under pressure with cooling, skin BFO both in people with SCI and AB controls were more regular at multiple time scales during hyperemia compared to baseline, whereas under pressure with no temperature change and particularly pressure with heating, BFO were more irregular during hyperemia compared to baseline. Moreover, the results of surrogate tests indicated that changes in the degree of regularity of BFO from baseline to hyperemia were only partially attributed to changes in relative amplitudes of endothelial, neurogenic, and myogenic components of BFO. These findings support the use of MSE to assess the efficacy of local cooling on reactive hyperemia and assess the degree of skin ischemia in people with SCI.

scholarly journals Assessment of Diabetic Autonomic Nervous Dysfunction with a Novel Percussion Entropy Approach

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Hai-Cheng Wei ◽  
Ming-Xia Xiao ◽  
Na Ta ◽  
Hsien-Tsai Wu ◽  
Cheuk-Kwan Sun
Keyword(s):  
Blood Sugar ◽  
Hba1c Level ◽  
Fasting Blood Sugar ◽  
Sugar Concentration ◽  
Multiscale Entropy ◽  
Small Scale ◽  
Early Screening ◽  
Entropy Index ◽  
Additional Information ◽  
Blood Sugar Concentration

This study investigated the validity of a novel parameter, percussion entropy index (PEI), for assessing baroreflex sensitivity. PEI was acquired through comparing the similarity in tendency of change between the amplitudes of successive digital volume pulse (DVP) signals and changes in R-R intervals (RRI) of successive cardiac cycles. Totally 108 upper middle-aged volunteers were divided into three groups: healthy subjects (Group 1, age 41–80, n=41), those with well-controlled type 2 diabetes mellitus (T2DM) (Group 2, age 41–82, n=36, glycated hemoglobin (HbA1c)<6.5%), and patients with poorly controlled T2DM (Group 3, age 44–77, n=31, HbA1c≧6.5%). Percussion entropy index (PEI) was computed from DVP signals acquired through photoplethysmography (PPG) and RRI from electrocardiogram in 1000 successive cardiac cycles for each subject. Autonomic function was also assessed by Poincaré index (SD1/SD2 ratio, SSR), low- to high-frequency power ratio (LFP/HFP, LHR), and small-scale multiscale entropy index (MEISS) for comparison. Demographic, anthropometric, hemodynamic, and serum biochemical parameters of all testing subjects were obtained for investigating the significance of associations with the three parameters. The results showed that MEISS and PEI successfully discriminated among the three groups (p<0.017). However, only PEI showed significant associations with indicators of both acute (i.e., fasting blood sugar concentration, p<0.017) and chronic (i.e., HbA1c level, p<0.001) blood sugar control. Multivariate analysis also showed significant associations of PEI with fasting blood sugar and HbA1c levels in all subjects. The interpreting effect of the two independent variables, HbA1c level and fasting blood sugar concentration, on PEI was 71.4% and 12.3%, respectively. In conclusion, the results demonstrated that additional information on diabetic autonomic dysfunction can be obtained through comparing two simultaneously acquired physiological time series. The significant associations of percussion entropy index with indicators of blood sugar control also highlight its possible role in early screening of the disease.

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