Association between Systolic Blood Pressure Difference ≥10 mm Hg and Ankle-Brachial Index

Background: In new outpatients, blood pressure should be measured in both arms. A previous study reported that an inter-arm systolic blood pressure difference (ΔSBP) of ≥10 mm Hg is associated with an increased risk of mortality. Aim: The aim was to identify the associations with absolute values of ΔSBP (|ΔSBP|) ≥10 mm Hg. Subjects and Methods: This study included 2481 patients. Patients with a body mass index ≥25 kg/m2 were defined as obese. The group of A was defined as following: ankle-brachial index (ABI) was <0.9 or ≥1.3. ΔSBP was expressed as right arm BP minus left arm BP. |ΔSBP| ≥10 mm Hg were analyzed using multivariate logistic analysis. Results: |ΔSBP| ≥10 mm Hg was found in 6.0% of patients and |ΔSBP| < 5 mm Hg in 80.4%. In multivariate analysis, the odds ratios (ORs) of the associations with |ΔSBP| ≥10 mm Hg were significantly associated with abnormal ABI and obesity regardless of sex and age. Moreover, the OR of the combined effects of abnormal ABI and obesity was higher than that of abnormal ABI and obesity alone. Conclusion: |ΔSBP| ≥10 mm Hg was associated with abnormal ABI and obesity. In a primary care setting, blood pressure should be actively measured in both arms. This study suggests that the associations with |ΔSBP| ≥10 mm Hg may be a useful part of screening for abnormal ABI.

Relationship between gestational body mass index,blood pressure variability,and postpartum depression in pregnant women with preeclampsia

BACKGROUND Pre-eclampsia has long been proven to be an independent risk factor for postpartum depression(PPD).Excessive increase in body mass index(BMI)during pregnancy is an important factor inducing pre-eclampsia.Increased blood pressure is the main symptom of patients with pre-eclampsia.However,whether there is a correlation between BMI and blood pressure variability during pregnancy and PPD occurrence in pregnant women with pre-eclampsia remains unclear.AIM To investigate the relationship between BMI,blood pressure variability,and PPD in pregnant women with pre-eclampsia.METHODS Using a cross-sectional survey research,201 pregnant women with pre-eclampsia who were treated and delivered in Suzhou Ninth People’s Hospital from May 2016 to June 2024 were selected as this study’s subjects.At 42 days after delivery,the subjects were re-examined in the hospital’s outpatient department.The Edinburgh Postnatal Depression Scale(EPDS)was used to evaluate whether PPD symptoms,divided the subjects into two groups:The PPD and non-PPD groups.We analyzed clinical data,changes in BMI during pregnancy,and blood pressure variability in the two groups.The Pearson method was used to test the correlation between BMI increase,blood pressure variability during pregnancy,and EPDS score in patients with pre-eclampsia.Logistic regression analysis was performed to explore whether increased BMI and blood pressure variability during pregnancy are influencing factors for PPD occurrence in patients with pre-eclampsia.RESULTS Of the 201 pre-eclamptic women who underwent an outpatient review 42 days after delivery,37 had PPD symptoms based on the EPDS scale evaluation,resulting in an incidence rate of 18.41%(37/201).The differences between the PPD and non-PPD groups in terms of age,educational level,place of residence,reproductive history,gestational age,mode of delivery,newborn gender,and newborn birth weight were not statistically significant(P>0.05).The gestational BMI increase,24-hour systolic blood pressure(SBP)variability,and 24-hour diastolic blood pressure(DBP)variability in the PPD group were significantly higher than those in the non-PPD group;the differences were statistically significant(P<0.001).Pearson correlation analysis showed that BMI increase,SBP variability,and DBP variability during pregnancy correlated positively with the EPDS score of pregnant women with pre-eclampsia(r=0.349,0.336,and 0.241;P<0.001).Logistic regression analysis showed that a high increase in BMI during pregnancy[odds ratio(OR)=4.614,95%confidence interval(CI):1.749-12.170,P=0.002],large variability in 24-hour SBP(OR=2.910,95%CI:1.322-6.404,P=0.008),and large variability in 24-hour DBP(OR=2.347,95%CI:1.138-4.831,P=0.021)were factors affecting PPD occurrence in patients with pre-eclampsia.CONCLUSION Increased BMI and blood pressure variability during pregnancy can increase the risk of PPD in patients with preeclampsia.Strengthening pregnancy guidance and controlling fluctuations in BMI and blood pressure variability during pregnancy within a reasonable range can help reduce the risk of PPD in patients with pre-eclampsia.

Effects of body mass index on intraocular pressure and ocular pulse amplitude

AIM: To investigate the effects of body mass index (BMI) on intraocular pressure (IOP) and ocular pulse amplitude(OPA). METHODS: Totally 140 healthy individuals without any systemic diseases were included in the study. BMI (kg/m2) was calculated for every individual. IOP and OPA were measured with Pascal Dynamic contour tonometer (DCT). Blood pressure was also measured along with the DCT. The patients were divided into three groups according to BMI as: Group1, BMI<25; Group2, 25≤BMI<30; Group3, BMI≥30. Mean values of IOP, OPA, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were used in statistical analysis.RESULTS: In Group1, the means of IOP, OPA, were 16.8±2.3mmHg, 2.7±0.7mmHg respectively; and SBP, DBP were 120.0±6.1mmHg, and 77.4±5.6mmHg respectively. In group2, the mean IOP, OPA, SBP, and DBP were found to be 16.6±2.1mmHg, 2.4±0.7mmHg, 121.7±5.3mmHg, and 79.5±4.9mmHg respectively. In group3, the mean IOP, OPA, SBP, and DBP were found to be 17.3±1.7mmHg, 2.1±0.7mmHg, 122.4±5.7mmHg, and 79.7±5.2mmHg respectively. There were no statistically significant difference between groups in terms of IOP, SBP and DBP, while OPA values were significantly lower in group3 (P=0.001). CONCLUSION: Decreased OPA values in individuals with higher BMI may indicate that subjects with higher BMI have lower choroidal perfusion and lower ocular blood flow.

Influence of vapor pressure deficit on vegetation growth in China

Vapor pressure deficit(VPD)plays a crucial role in determining plant physiological functions and exerts a substantial influence on vegetation,second only to carbon dioxide(CO_(2)).As a robust indicator of atmospheric water demand,VPD has implications for global water resources,and its significance extends to the structure and functioning of ecosystems.However,the influence of VPD on vegetation growth under climate change remains unclear in China.This study employed empirical equations to estimate the VPD in China from 2000 to 2020 based on meteorological reanalysis data of the Climatic Research Unit(CRU)Time-Series version 4.06(TS4.06)and European Centre for Medium-Range Weather Forecasts(ECMWF)Reanalysis 5(ERA-5).Vegetation growth status was characterized using three vegetation indices,namely gross primary productivity(GPP),leaf area index(LAI),and near-infrared reflectance of vegetation(NIRv).The spatiotemporal dynamics of VPD and vegetation indices were analyzed using the Theil-Sen median trend analysis and Mann-Kendall test.Furthermore,the influence of VPD on vegetation growth and its relative contribution were assessed using a multiple linear regression model.The results indicated an overall negative correlation between VPD and vegetation indices.Three VPD intervals for the correlations between VPD and vegetation indices were identified:a significant positive correlation at VPD below 4.820 hPa,a significant negative correlation at VPD within 4.820–9.000 hPa,and a notable weakening of negative correlation at VPD above 9.000 hPa.VPD exhibited a pronounced negative impact on vegetation growth,surpassing those of temperature,precipitation,and solar radiation in absolute magnitude.CO_(2) contributed most positively to vegetation growth,with VPD offsetting approximately 30.00%of the positive effect of CO_(2).As the rise of VPD decelerated,its relative contribution to vegetation growth diminished.Additionally,the intensification of spatial variations in temperature and precipitation accentuated the spatial heterogeneity in the impact of VPD on vegetation growth in China.This research provides a theoretical foundation for addressing climate change in China,especially regarding the challenges posed by increasing VPD.

Ankle-brachial index and brachial-ankle pulse wave velocity are risk factors for ischemic stroke in patients with type 2 diabetes

The incidence of ischemic stroke in patients with diabetes is increasing. While brachial-ankle pulse wave velocity （BaPWV） and ankle-bra- chial index （ABI） are known to be associated with ischemic cardiovascular and cerebrovascular diseases, whether these measures predict the risk of ischemic cerebrovascular disease in diabetic patients remains unclear. 117 patients with type 2 diabetes were enrolled in this study. According to the results of head magnetic resonance imaging, the patients were divided into a diabetes-only group （n = 55） and a diabetes and ischemic stroke group （n = 62）. We then performed ABI and BaPWV examinations for all patients. Compared with the diabe- tes-only group, we found decreased ABI and increased BaPWV in the diabetes and ischemic stroke group. Multivariate logistic regression analyses revealed that BaPWV and ABI were risk factors for ischemic stroke in patients with type 2 diabetes. Our findings indicate that decreased ABI and increased BaPWV are objective indicators of increased risk of ischemic stroke in patients with type 2 diabetes.

Ankle-brachial index as a predictor of all-cause and cardio- vascular disease mortality in 3733 Chinese patients with high cardiovascular risk

Objective To assess the association between 1-year risk of all-cause and cardiovascular disease （CVD） mortality and ankle-brachial index （ABI） in Chinese patients who were at high CVD risk. Methods Totally 3733 patients with high CV risk had bilateral ABI measurements at baseline and were followed up for 1-1.5 years. Patients were divided to four groups： 1） coronary heart disease （CHD）; 2） ischemic stroke （IS）; 3） diabetes mellitus （DM）; 4） very high risk group（VHR）, low ABI was defined as 〈0.9. Results A total of 3179 patients were analyzed. The prevalence of low ABI was 28.1%. At 1 year, all-cause mortality was 8.7%, and 27.6% was attributable to CVD; mortality due to CV events was 4.8% and 1.5%. After adjusting other risk factors the hazard ratio of low ABI was 1.623 for all-cause mortality and 2.304 for CVD mortality. Similar in patient with and without low ABI, respectively were found in four groups.Conclusion ABI is a strong and independent predictor ofrnortality. Patients with a low ABI have a substantially increased risk of all-cause mortality and CVD mortality （J Geriatr Cardio12010; 7：17-20）.

Association of Race and Change in Ankle-Brachial Index: The Atherosclerosis Risk in Communities (ARIC) Cohort

Objective: This study evaluates the association of self-reported race with change in ankle-brachial index (ABI) over time and modification of this association by paraoxonase gene (PON1, PON2 and PON3) single nucleotide polymorphisms (SNPs). Methods: This longitudinal study included 11,992 (N = 2952 Black, N = 9040 White) participants from the Atherosclerosis Risk in Communities (ARIC) cohort with PON genotyping. Mixed-effects models examined whether race was associated with change in ABI over time after adjustment for known peripheral artery disease (PAD) risk factors. Results: Change in ABI over time differed between Whites and Blacks (race-time interaction, p < 0.0001). Stratified analyses showed that ABI values were better in both Blacks and Whites who completed high school or more education compared to those who completed less education. None of the PON SNPs met the significance level (p < 0.001) after Bonferroni correction for multiple comparisons. Conclusions: ABI differences by race were small and although statistically significant, may not be clinically significant. Change in ABI over time varies by race and may be modified by education. Results suggest that higher education may influence the lifestyle and behavioral choices contributing to better ABI in both Blacks and Whites. Further studies are needed to confirm this observation.

Screening of Peripheral Artery Disease by Systematic Measurement of Ankle-Brachial Index among Diabetic Patients in Dakar

Introduction: The peripheral artery disease (PAD) is one of the chronic and frightening vascular complications of the diabetes whose tracking can be done by the Ankle-Brachial Index (ABI) measurement. We conducted in this context a study which consisted in measuring the ABI among hospitalized diabetic patients at Teaching Hospital of Pikine in Dakar, over 18 months’ duration. The aim was to determine the prevalence and evaluate factors correlated to the presence of the PAD. Patients and Method: This cross-sectional descriptive study interested the whole of diabetic patients hospitalized in Internal Medicine/Endocrinology Department, from January 2013 to June 2014. We carried out a complete clinical examination associated with ABI measurement by a Doppler probe for each included patient after having collected the clinical and paraclinical data. Results: Our population of study comprised 209 diabetic patients with a female predominance (126, 60.3%). The sex-ratio man/woman was 0.6. The median age of the population of study was 54 ± 2 years. In our series, 157 (75.1%) patients discovered their diabetes with the waning of an affection while the 52 (24.9%) other patients discovered their diabetes at the time of a systematic assessment. The PAD appeared by an intermittent claudication among 38 patients (18.2%). The ABI was normal for 126 patients (60.3%). The ABI was low for 51 patients (24.4%), unilateral in 3.8% of cases and bilateral in 20.6% of cases. The ABI was high among 32 patients (15.3%), unilateral in 7.2% of cases and bilateral in 8.1% of cases. The ABI extremes values were 0.11 and 2. In the population of study, 46 patients (22%) had a well-compensated PAD. The PAD was low compensated for 3 patients (1.4%) and severe for 2 patients (1%). The ABI was more frequent and significantly among women than men, with 32 cases (25.4%) against 19 (22.9%) cases (p = 0.021). The proportion of low ABI was more important among patients whose diabetes had evolved for more than 5 years (42.3% of cases) with a peak of frequency in the duration of 6 - 10 years (47.7% of cases). Conclusion: The PAD global prevalence among hospitalized diabetic patients appeared high with 24.4% patients presenting low ABI. Its early diagnosis among subjects at risk as for our study population allowed identifying asymptomatic subjects having another cardiovascular damage. Thus, the screening of obstructive arteriopathy of lower limb PAD by the measurement of ABI should be applied to all diabetic patients for a better assessment of atherosclerotic complication.

Correlation of Inferior Vena Cava Respiratory Variability Index with Central Venous Pressure and Hemodynamic Parameters in Ventilated Pigs with Septic Shock

Septic shock is a common critical condition, for which effective early fluid resuscitation is the therapeutic focus. According to the 2008 international guidelines for management of severe sepsis and septic shock, resuscitation should achieve a central venous pressure （CVP） of 8-12 mmHg within the first 6 h. However, it is still uncertain about the sensitivity and specificity of CVP in reflecting the cardiac preload. Ultrasonography is a simple, rapid, non-invasive, and repeatable method for the measurement of sensitivity and specificity of CVP and has thus gradually attracted the increasing attention of physicians. It was reported that ultrasonography can show the inferior vena cava diameter, respiratory variability index, and blood volume in patients with sepsis or heart failure.

Relationship between sleep quality and blood pressure level in nurses performing shift work

Objective:The aim of the study was to evaluate the quality of sleep in nurses performing shift work in therapeutic and surgical depar tments and to establish possible relationships between level of blood pressure(BP)and quality of sleep.Methods:A total of 20 nurses of the therapeutic depar tments and 20 nurses of the surgical depar tments were enrolled in the study.Sleep quality was assessed using the Pittsburgh Sleep Quality Index(PSQI).BP was measured according to the standard protocol using the Korotkoff method;a sphygmomanometer was used for this twice with an interval of 2 min between 10:00 a.m.and 10:30 a.m.The average value for the 2 indicators was calculated.The diagnosis of essential ar terial hyper tension(AH)was established according to the recommendations of the European Association of Cardiology and the European Association of Hypertension(2018).Results:The overall assessment of the sleep quality of the nurses involved in shift work indicates poor sleep quality;this was true in respondents of both the surgical and therapeutic profiles.However,it was observed that the quality of sleep was significantly lower in nurses of the therapeutic departments.Moreover,poor sleep quality was associated with AH,which was diagnosed in 65%of the nurses of the therapeutic departments and 45%of the nurses of the surgical departments,that is,in almost all of the subjects.Herewith,in the nurses of the therapeutic departments,the level of systolic BP exceeded that of the nurses of the surgical departments.Conclusions:Poor sleep quality is a significant risk factor for AH development and is relevant to nurses performing shift work.Additional clinical studies should be conducted to better understand the mechanisms underlying such adverse cardiometabolic outcomes associated with sleep disorders in the health-sector shift workers.

Nitroglycerin reduces augmentation index and central blood pressure independent of effects on cardiac preload

Objective To determine whether reduction in central pressure augmentation and central systolic blood pressure by nitroglycerine (NTG) results from effects on pre-load or is due to arterial dilation. Methods We compared effects of NTG with those of lower body negative pressure (LBNP). Hemodynamic measurements were made at rest,during LBNP (10,20 and 30 mmHg,each for 15 min) and after NTG (10,30 and 100 μg/min,each dose for 15 min) in ten healthy volunteers. Cardiac pre-load,stroke volume and cardiac output were assessed by echocardiography. Central pressure augmentation and central systolic pressure were obtained by radial tonometry using a transfer function. Results LBNP (20 mmHg) and NTG (30 μg/min) reduced pre-load (as measured by the peak velocity of the S wave in the superior vena cava) to a similar degree [by (26.8±3.8)% and (23.9±3.4)%,respectively]. Compared to LBNP,NTG reduced systemic vascular resistance [by (32.9±7.5)%,P<0.01],decreased peripheral and central pressure augmentation [by (20.8±3.4)% units and (12.9±2.9)% units,respectively,each P<0.01]. Conclusion These results suggest that a reduction in pre-load does not explain reduction in pressure augmentation and central systolic blood pressure by NTG and that these effects are mediated through arterial dilation.

Pulse palpation and limited joint mobility examination are better indicators than oscillometric measurement for diagnosing abnormal ankle-brachial index

Background: Peripheral artery disease (PAD) is the least recognized form of atherosclerosis and may even result in amputation if the diagnosis is delayed. Manual pulse palpation is the traditional way to diagnose PAD. Doppler ultrasonographic measurement of ankle-brachial index (ABI) is the gold standard diagnosing method but requires training and is not necessarily available as an outpatient procedure. Using automated oscillometric blood pressure devices has been suggested as an easier method for measuring the ABI. Methods: A single observer palpated the arterial dorsalis pedis, examined hand joints and measured the ABI of one hundred diabetic patients using both Doppler and oscillometric methods. The purpose of this study was to compare the oscillometric method and the manual diagnosing methods to the gold standard method of using a hand held Doppler device for measuring the ABI and detecting PAD. Results: ABI was abnormal in 24 patients (24%) (22 males, 2 females) when measured with the Doppler method. Of these 24 patients, the oscillometric method would have missed 12 giving 12 false negatives. We found that the sensitivity of the oscillometric method was 50.0% and specificity 90.8%. Clinical examination with palpation of ADP combined with limited joint mobility (LJM) scoring would have missed only four cases. Conclusions: Although the oscillometric method is easy and accessible, it is not sensitive enough to be used as the only method in measuring ABI. The simple and inexpensive ADP pulse palpation combined with testing for LMJ was able to find 20 of the 24 (83%) patients with an abnormal ABI measured by Doppler stethoscope.

Importance of Ankle/Brachial Pressure Index in Saudi Patients with Coronary Artery Disease

Background: The ankle/brachial pressure index (ABPI) has been shown to be a good marker of systemic atherosclerosis and a powerful predictor of cardiovascular morbidity and mortality. The objective of this study was to determine the importance of measuring ABPI in Saudi patients with coronary artery disease (CAD). METHODS: This is a hospital based cross-sectional study which was conducted on all Saudi patients who underwent coronary angiography without symptoms of peripheral arterial disease at King Fahd Hospital of the University, Al-Khobar Saudi Arabia. All patients underwent measurement of their ABPI. The study was carried out between December 2010 and November 2011. RESULTS: During the study period, two hundred and five patients were included. Fifty-nine (28.8%) patients were Group II (ABPI ≤ 0.90) and the rest was Group I (ABPI > 0.90). Significant correlation was also found between low ABPI and the extent of CAD (mean number of arteries involved in Group I was 1.78 ± 0.83 compared to 2.10 ± 0.736 in Group II p = 0.011). Nevertheless, the correlation between low ABPI, and the severity of presentation of CAD were also significant (Incidence of myocardial infarction with congestive heart failure was 0.5% in Group I compared to 12% in Group II p CONCLUSION: The ABPI is an important prognostic indicator for Saudi patients with CAD.

Analysis of Ankle-Brachial Index, Waist-Hip Ratio, Ejection-Fraction, Obesity, Smoking, Alcohol Habits, Diabetes and Hypertension as Independent Predictors of Complexity and Severity of Coronary Artery Disease

Background: The present study was conducted to examine the association between various coronary risk factors and clinical parameters, with special emphasis on ankle-brachial index, in predicting the severity and complexity of coronary artery disease. Methods: Patients diagnosed with coronary artery disease at our hospital between September-2012 and December-2014 were examined in this study. Selected patients were screened for cardiovascular risk factors including diabetes, hypertension, smoking, and alcohol habits as well as for clinical parameters including body-mass index, waist-hip ratio, ankle-brachial index, and ejection fraction. All patients underwent coronary angiography and were evaluated for severity of coronary artery disease (based on number of vessels involved) and complexity of coronary angiographic lesions (measured by computer-assisted Syntax score calculator). The collected data were analyzed to determine the role of cardiovascular risk factors and clinical parameters as predictors of complexity and severity of coronary artery disease. Results: A total of 211 patients (mean age: 54.64 ± 9.9 years;81% males) with coronary artery disease were analyzed. Findings revealed that diabetes mellitus (p < 0.001), hypertension (p < 0.001), smoking habits (p = 0.036), and low ankle-brachial index (p < 0.001) were independent predictors of complex coronary artery disease as measured by Syntax score. Significant associations were also evident between severity of coronary artery disease and diabetes mellitus (p < 0.001), hypertension (p < 0.001), and ankle-brachial index (p < 0.001). Conversely, other cardiovascular risk factors including body-mass index, alcohol habits, wait-hip ratio, and ejection fraction did not exhibit significant associations with severity and complexity of coronary artery. Conclusions: The early diagnosis of coronary artery can be predicated by evaluating diabetes, hypertension, and smoking habits in patients presenting with acute coronary syndrome. In addition, ankle-brachial index can be used as an effective non-invasive bed-side tool, as an alternative to Syntax score, in predicting the severity and complexity of coronary artery disease.

Ankle-Brachial Index in Systemic Lupus Erythematosus:A Senegalese Case-Control Study

Systemic lupus erythematosus (SLE) is associated with accelerated atherosclerosis and increasing cardiovascular risk which is recognized as a major cause of morbidity and death. Whether subclinical atherosclerosis has been evaluated by several methods, there are very limited data about Ankle-Brachial Index (ABI) in patients with systemic lupus erythematosus. The aim of the present study was to compare this index, between SLE patients and controls. We conducted a case-control study in the Department of Internal Medicine of our institution during the period from August 1, 2017 to December 31, 2018. We included 100 subjects, including 50 SLE patients and 50 control cases. This included 44 women and 6 men in patients with an identical distribution in controls. The mean age was 33.5 ± 11.3 years for cases and 33.3 ± 11.3 years (p-value: 0.93) for controls subjects. There was higher frequency of cardiovascular risk factors such as dyslipidemia (p-value at 0.009), low level of serum HDL-cholesterol (p-value??0.001), hypertriglyceridemia (p-value at 0.000) and hyperuricemia (p-value at 0.000) in patients with SLE. Overweight/obesity was higher in controls subjects (p-value at 0.028). There was no statistically significant difference in the frequency of diabetes-mellitus, smoking and high blood pressure. The abnormally ABI was recorded in 19 patients with SLE (38%) and 8 controls (16%) with a p-value: 0.01 and odds ratio: 3.22. Eight patients (16%) and four controls (8%) had low ABI without significant difference (p-value: 0.11 but odds-ratio at 2.98). Eleven patients with SLE (22%) and five controls (10%) had high ABI (p-value: 0.05 and odds-ratio: 3.24). In patients with SLE only disease activity (cSLEDAI) at the inclusion of the study was correlated?to abnormal ABI.?Conclusion:?This study showed an increasing prevalence of abnormal ABI in black African patients with SLE compared to controls with a correlation between disease activity and abnormal ABI.

A new method to construct reservoir capillary pressure curves using NMR log data and its application

By analyzing hundreds of capillary pressure curves, the controlling factors of shape and type of capillary pressure curves are found and a novel method is presented to construct capillary pressure curves by using reservoir permeability and a synthesized index. The accuracy of this new method is verified by mercury-injection experiments. Considering the limited quantity of capillary pressure data, a new method is developed to extract the Swanson parameter from the NMR T2 distribution and estimate reservoir permeability. Integrating with NMR total porosity, reservoir capillary pressure curves can be constructed to evaluate reservoir pore structure in the intervals with NMR log data. An in-situ example of evaluating reservoir pore structure using the capillary pressure curves by this new method is presented. The result shows that it accurately detects the change in reservoir pore structure as a function of depth.

Comparison of walking quality variables between incomplete spinal cord injury patients and healthy subjects by using a footscan plantar pressure system

The main goal of spinal cord rehabilitation is to restore walking ability and improve walking quality after spinal cord injury(SCI). The spatiotemporal parameters of walking and the parameters of plantar pressure can be obtained using a plantar pressure analysis system. Previous studies have reported step asymmetry in patients with bilateral SCI. However, the asymmetry of other parameters in patients with SCI has not been reported. This was a prospective, cross-sectional study, which included 23 patients with SCI, aged 48.1 ± 14.5 years, and 28 healthy subjects, aged 47.1 ± 9.8 years. All subjects underwent bare foot walking on a plantar pressure measurement device to measure walking speed and spatiotemporal parameters. Compared with healthy subjects, SCI patients had slower walking speed, longer stride time and stance time, larger stance phase percentage, and shorter stride length. The peak pressures under the metatarsal heads and toe were lower in SCI patients than in healthy subjects. In the heel, regional impulse and the contact area percentage in SCI patients were higher than those in healthy subjects. The symmetry indexes of stance time, step length, maximum force, impulse and contact area were increased in SCI patients, indicating a decline in symmetry. The results confirm that the gait quality, including spatiotemporal variables and plantar pressure parameters, and symmetry index were lower in SCI patients compared with healthy subjects. Plantar pressure parameters and symmetry index could be sensitive quantitative parameters to improve gait quality of SCI patients. The protocols were approved by the Clinical Research Ethics Committee of Shengjing Hospital of China Medical University(approval No. 2015 PS54 J) on August 13, 2015. This trial was registered in the ISRCTN Registry(ISRCTN42544587) on August 22, 2018. Protocol version: 1.0.

Pressure Angle in Parallel Mechanisms: From Planar to Spatial

This paper presents the evolution process of pressure angles from planar parallel mechanisms to spatial parallel mechanisms. Manipulability and condition number, which are frequently used in the optimum design of parallel mechanisms, are introduced from serial robots at first. Then, both theoretical analysis and practical experiences demonstrate that these concepts seem imperfect when they are used in parallel mechanisms. For this reason, this paper introduces the pressure angles in planar 4-bar mechanisms to spatial parallel mechanisms, which include redundant parallel mechanisms. Two kinds of pressure angles extracted from the determinant of direct and indirect Jacobian matrices are investigated. Moreover, two comprehensive and visible global performance indices are defined, showing the advantages in evaluating the workspace, singularity and motion/force transmission capabilities. With a 2-DOF planar and a 3-DOF spatial parallel mechanism as examples, the application of the performance indices is investigated and compared with the condition number at last. The proposed concept can be extended to other spatial parallel mechanisms.

Blood pressure and stature in Helicobacter pylori positive and negative persons

To evaluate vital signs and body indices in Helicobacter pylori (H. pylori) positive and negative persons. A total of 22 centres entered the study. They were spread over the whole country, corresponding well to the geographical distribution of the Czech population. A total of 1818 subjects (aged 5-98 years) took part in the study, randomly selected out of 38147 subjects. H. pylori infection was investigated by means of a 13C-urea breath test. Data on height, weight, systolic and diastolic blood pressure and heart rate were collected at the clinics of general practitioners. The overall prevalence of H. pylori infection was 30.4% (402/1321) in adults (≥ 18 year-old) and 5.2% (26/497) in children and adolescents (≤ 17 year-old). Once adjusted for age and gender, only a difference in body mass index remained statistically significant with H. pylori positive adults showing an increase of 0.6 kg/m2 in body mass index. Once adjusted for age and gender, we found a difference in height between H. pylori positive and H. pylori negative children and adolescents. On further adjustment for place of residence, this difference became statistically significant, with H. pylori positive children and adolescents being on average 3.5 cm shorter. H. pylori positive adults were significantly older compared to H. pylori negative subjects. Once adjusted for age and gender, H. pylori infection had no impact on body weight, body mass index and vital signs either in adults or children and adolescents. Chronic H. pylori infection appeared to be associated with short stature in children. H. pylori infection did not influence blood pressure, body weight and body mass index either in adults or children and adolescents.

Buckling of Cassini Oval Pressure Hulls Subjected to External Pressure

The paper focuses on Cassini oval pressure hulls under uniform external pressure. The Cassini oval pressure hull is proposed based on the shape index of Cassini oval. The buckling of a series of Cassini oval pressure hulls with the shape index of 0.09–0.30 and one spherical pressure hull with the diameter of 2 m is devoted. Such hulls are numerically studied in the case of constant volume, material properties, and wall thickness. The results show that Cassini oval pressure hulls with the shape index of 0.10–0.11 can resist about 4% more external pressure than the spherical one. This deviates from the classical mechanics conclusion that spherical shell is the optimal shape for underwater pressure resistant structures.