Evaluation Of Arterial Stiffness Research Articles

Automatic Measurement of End-Diastolic Arterial Lumen Diameter in ARTSENS

Over past few years, we are developing a system for facilitating large scale screening of patients for cardiovascular risk—arterial stiffness evaluation for noninvasive screening (ARTSENS). ARTSENS is an image-free device that uses a single element ultrasound transducer to obtain noninvasive measurements of arterial stiffness (AS) in a fully automated manner. AS is directly proportional to end-diastolic lumen diameter (Dd). Multilayered structure of the arterial walls and indistinct characteristics of intima-lumen interface (ILI) makes it quite difficult to accurately estimate Dd in A-mode radio-frequency (RF) frames obtained from ARTSENS. In this paper, we propose a few methods based on fitting simple mathematical models to the echoes from arterial walls, followed by a novel method to fuse the information from curve fitting error and distension curve to arrive at an accurate measure of Dd. To bring down the curve fitting time and facilitate processing on low-end processors, a novel approach using the autocorrelation of echoes from opposite walls of the artery has been discussed. The methods were analyzed for their comparative accuracy against reference Dd obtained from 85 human volunteers using Hitachi-Aloka eTRACKING system. Dd from all reported methods show strong and statistically significant positive correlation with eTRACKING and mean error of less than 7% could be achieved. As expected, Dd from all methods show significant positive correlation with age.

Response to Letter to the Editor

We acknowledge the fact that blood pressure (BP) and lipid lowering medication could affect arterial stiffness, as suggested by Varol and Arslan [ [1] Varol E. Arslan A. Antihypertensive Drugs and Statins Should Be Considered in Arterial Stiffness Evaluation in Ethnic Differences. 2015 Google Scholar ]. For BP lowering medication, the effect on arterial stiffness may principally result from a direct effect on BP. To explore the effects of BP and lipid lowering medication, we performed additional analyses on the use of these medications among our study population, and examined the effect of excluding participants who were using these types of medication on ethnic differences in arterial stiffness.

Antihypertensive drugs and statins should be considered in arterial stiffness evaluation in ethnic differences

Antihypertensive drugs and statins should be considered in arterial stiffness evaluation in ethnic differences

1D.05

Objective: The loss of physiological stiffness mismatch between aorta and peripheral arteries was strongly and independently associated with increased mortality in adult dialysis population. The aim of the study was to evaluate if the reversal of arterial stiffness mismatch was present in pre-dialysis patients with chronic kidney disease (CKD). Design and method: The aortic-brachial arterial stiffness mismatch (pulse wave velocity (PWV ratio) were assessed using carotid-femoral PWV divided by carotid-radial PWV in 112 adult treated hypertensive CKD patients: 54 - with CKD IIIa (age 59,5 ± 8,4 years, male 46,3%, brachial blood pressure (BP) 149,6 ± 10,3/85,8 ± 9,8 mmHg), 35 - with CKD IIIb (age 60,2 ± 7,8 years, male 45,7%, BP 152,5 ± 12,5/86,4 ± 10,2 mmHg) and 23 with CKD IV (age 57,3 ± 10,2, male 43,4%, BP 156,1 ± 14,3/92,8 ± 12,4 mmHg). P < 0,05 was considered significant for group comparisons, Spearman correlation test and multivariate regression analysis. Results: In CKD IIIa aortic PWV was 10,2 ± 2,0 m/s, brachial PWV 12,9 ± 1,6 m/s, PWV ratio 0,82 ± 0,25. In CKD IIIb aortic PWV was 11,3 ± 2,9 m/s, brachial PWV 12,2 ± 1,8 m/s, PWV ratio 0,90 ± 0,27. In CKD IV aortic PWV was 12,7 ± 3,1 m/s (p < 0,05 vs CKD IIIa), brachial PWV 11,4 ± 1,6 m/s (p < 0,05 vs CKD IIIa), PWV ratio 1,09 ± 0,33 (p < 0,05 vs CKD IIIa). Increased aortic stiffness (aortic PWV>10 m/s) was observed in 55,6%, 62,9% and 73,9%, respectively. For the whole study population (n = 112) multivariate analysis revealed independent significant correlation between aortic PWV and glomerular filtration rate (GFR) β=-0,36 (p < 0,05), PWV ratio and GFR β=-0,32 (p < 0,05), PWV ratio and age β=0,44 (p < 0,05). Conclusions: In the pre-dialysis hypertensive CKD patients worsening of kidney function was associated with discordant changes in aortic and brachial artery stiffness in the reversal of the physiological stiffness mismatch. The loss of this physiological mismatch may promote kidney damage through increased forward pressure wave transmission into the microcirculation. PWV ratio evaluation (in addition to traditional aortic PWV measurement) may be useful for better evaluation of arterial stiffness in pre-dialysis CKD patients.

2-D arterial wall motion imaging using ultrafast ultrasound and transverse oscillations.

Ultrafast ultrasound is a promising imaging modality that enabled, inter alia, the development of pulse wave imaging and the local velocity estimation of the so-called pulse wave for a quantitative evaluation of arterial stiffness. However, this technique only focuses on the propagation of the axial displacement of the artery wall, and most techniques are not specific to the intima-media complex and do not take into account the longitudinal motion of this complex. Within this perspective, this paper presents a study of two-dimensional tissue motion estimation in ultrafast imaging combining transverse oscillations, which can improve motion estimation in the transverse direction, i.e., perpendicular to the beam axis, and a phase-based motion estimation. First, the method was validated in simulation. Two-dimensional motion, inspired from a real data set acquired on a human carotid artery, was applied to a numerical phantom to produce a simulation data set. The estimated motion showed axial and lateral mean errors of 4.2 ± 3.4 μm and 9.9 ± 7.9 μm, respectively. Afterward, experimental results were obtained on three artery phantoms with different wall stiffnesses. In this study, the vessel phantoms did not contain a pure longitudinal displacement. The longitudinal displacements were induced by the axial force produced by the wall's axial dilatation. This paper shows that the approach presented is able to perform 2-D tissue motion estimation very accurately even if the displacement values are very small and even in the lateral direction, making it possible to estimate the pulse wave velocity in both the axial and longitudinal directions. This demonstrates the method's potential to estimate the velocity of purely longitudinal waves propagating in the longitudinal direction. Finally, the stiffnesses of the three vessel phantom walls investigated were estimated with an average relative error of 2.2%.

Using new technologies to promote weight management: a randomised controlled trial study protocol.

BackgroundOver the last three decades, overweight and obesity and the associated health consequences have become global public health priorities. Methods that have been tried to address this problem have not had the desired impact, suggesting that other approaches need to be considered. One of the lessons learned throughout these attempts is that permanent weight loss requires sustained dietary and lifestyle changes, yet adherence to weight management programs has often been noted as one of the biggest challenges. This trial aims to address this issue by examining whether social media, as a potential health promotion tool, will improve adherence to a weight management program. To test the effectiveness of this measure, the designated program will be delivered via the popular social networking site Facebook, and compared to a standard delivery method that provides exactly the same content but which is communicated through a pamphlet. The trial will be conducted over a period of twelve weeks, with a twelve week follow-up. Although weight loss is expected, this study will specifically investigate the effectiveness of social media as a program delivery method. The program utilised will be one that has already been proven to achieve weight loss, namely The CSIRO Total Wellbeing Diet.Methods/designThis project will be conducted as a 3-arm randomised controlled trial. One hundred and twenty participants will be recruited from the Perth community, and will be randomly assigned to one of the following three groups: the Facebook group, the pamphlet group, or a control group. The Facebook Group will receive the weight management program delivered via a closed group in Facebook, the Pamphlet Group will be given the same weight management program presented in a booklet, and the Control Group will follow the Australian Dietary Guidelines and the National Physical Activity Guidelines for Adults as usual care. Change in weight, body composition and waist circumference will be initial indicators of adherence to the program. Secondary outcome measures will be blood glucose, insulin, blood pressure, arterial stiffness, physical activity, eating behaviour, mental well-being (stress, anxiety, and depression), social support, self-control, self-efficacy, Facebook activity, and program evaluation.DiscussionIt is expected that this trial will support the use of social media - a source of social support and information sharing - as a delivery method for weight management programs, enhancing the reduction in weight expected from dietary and physical activity changes. Facebook is a popular, easy to access and cost-effective online platform that can be used to assist the formation of social groups, and could be translated into health promotion practice relatively easily. It is anticipated in the context of the predicted findings that social media will provide an invaluable resource for health professionals and patients alike.Trial registrationAustralian New Zealand Clinical Trials Register (ANZCTR): ACTRN12614000536662. Date registered: 21 May 2014.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-015-1849-4) contains supplementary material, which is available to authorized users.

Evaluation of endothelial function and arterial stiffness in HIV-infected patients: a pilot study.

In the era of combination antiretroviral therapy (cART), life expectancy of HIV-infected patients is the same as that of the general population, resulting in increasing prevalence of cardiovascular disease in this patient group. To assess the prevalence of endothelial dysfunction in HIV-infected patients and to identify factors which affect endothelial function and arterial stiffness. Thirty-seven adult HIV-infected patients, regardless of the fact and the type of cART, were enrolled into the study. In patient, reactive hyperaemia peripheral arterial tonometry assessment was performed using the Endo-PAT2000 device (ITAMAR®). This method allows evaluation of endothelial function ant arterial stiffness. Final analysis included 37 patients (median age 38 years, range 32-45 years), including 89.2% men. Endothelial dysfunction was found in 13 (35.1%) HIV-infected patients. We found no differences in demographic and clinical characteristics, laboratory data, and cardiovascular drug therapy between patients with or without endothelial dysfunction, except for platelet count which was higher in patients with endothelial dysfunction (174 [119-193] × 10³/mm3 vs. 222 [168-266] × 10³/mm³, p = 0.03). No demographic or clinical variables were identified as predictors of endothelial dysfunction in HIV-infected patients. In addition, no association was found between factors related to HIV infection, chronic drug therapy and the risk of endothelial dysfunction. Statistically significant correlations were found between arterial stiffness and age (rs = 0.53, p < 0.001), red blood cell count (rs = -0.39, p = 0.018), and platelet count (rs = 0.42, p = 0.009). CD4+ and CD8+ lymphocyte count and viral load were similar in patients with or without endothelial dysfunction. Arterial stiffness was significantly higher in patients with higher viral load (rs = -0.39, p = 0.0018) and in those with established AIDS (9.5 [1.0-16.0] vs. -5 [-10-5], p = 0.009). cART had no effect on endothelial dysfunction, while arterial stiffness was higher in patients treated with cART (10 [0-15] vs. -5 [-10-3], p = 0.014). Endothelial dysfunction is common in HIV-infected patients. In general, none of the analysed factors had an effect on endothelial function but cART had a negative effect on arterial stiffness.

Control of Hypertension in Erderly Patients Receiving Primary Care in Portugal: A Cross-sectional Study in 2013

Methods: Early vascular lesion detection technology was approved by Ministry of Health of the People’s Republic of China to be promoted to the whole China in 2004 and it was popularized in hundreds of hospitals in more than 20 provinces from 2004 to 2013. We started Chinese Arterial Stiffness Evaluation Study (CASE) in 2004. Results: The results of CASEStudy showed that: (1)Pulse wave velocity (PWV) and cardio ankle vascular index (CAVI) were significantly higher in vascular-related diseases including hypertension, metabolic syndrome and peripheral arterial diseases, and metabolic accompaniments might involve the increasing of arterial stiffness in hypertensionpatients. (2)Plasma homocysteine and N-Terminal pro-brain natriuretic peptide were positively correlated with arterial stiffness in hypertension and coronary artery disease patients indicating the relationship between arterial stiffness and biomarkers in vascular-related diseases. (3)There were differences about arterial stiffness between She nationality, Miao tribe and Buddhist monk population and life style modification was important for vascular health and vegetarian diet longer than 0.2 of life time could reduce arterial stiffness. (4)We founded and organized the first international vascular medicine congress-Chinese International Congress of VascularMedicine (CCVM) and established the first vascularmedicine center in China and set upVascularMedicine professional course inmedical colleges (PekingUniversityHealth Science Center) firstly. We established the early vascular lesion detection system and published the first guideline in 2005 and renewed this guideline in 2011. Conclusions: Our series studies have showed the importance of arterial function evaluation in vascular-related diseases; and a new disciplinevascular medicine has showed its great prospect in future.

An Imageless Ultrasound Device to Measure Local and Regional Arterial Stiffness.

Arterial stiffness (AS) has been shown to be an important marker for risk assessment of cardiovascular events. Local arterial stiffness (LAS) is conventionally measured by evaluating arterial distensibility at particular arterial sites through ultrasound imaging systems. Regional arterial stiffness (RAS) is generally obtained by evaluating carotid to femoral pulse wave velocity (cfPWV) through tonometric devices. RAS has a better prognostic value than LAS and cfPWV is considered as the gold standard of AS. Over the past few years our group has been developing ARTerial Stiffness Evaluation for Non-Invasive Screening (ARTSENS), an inexpensive and portable device to measure the LAS. It uses a single element ultrasound transducer to obtain A-Mode frames from the desired artery and is fully automated to enable a non-expert to perform measurements. In this work, we report an extension of ARTSENS to enable measurement of cfPWV that now makes it the only fully automatic device that can measure both LAS and RAS. In this paper, we provide a general review of the ARTSENS and compare it with other state-of-the-art AS measurement systems. cfPWV measurement using ARTSENS was cross-validated against SphygmoCor by successive measurements with both devices on 41 human subjects and excellent agreement between both devices was demonstrated (Coefficient of determination and, limits of agreement m/s). The inter-device correlation between ARTSENS and SphygmoCor was found to be better than other similar studies reported in the literature.

Evaluation of Arterial Stiffness in Patients with Behçet's Disease by Using Noninvasive Radiological Methods such as Intima-Media Thickness of the Carotid, Ankle-Brachial Pressure Index, Coronary Artery Calcium Scoring, and Their Relation to Serum Fetuin-A Levels: A Case-Control Study.

BackgroundBehçet's disease (BD) is a chronic, recurrent inflammatory systemic vasculitis. Evidence for increased atherosclerosis in BD has been observed. The relation between cardiovascular risk factors and increased atherosclerosis in patients with BD is still controversial.ObjectiveWe performed this study to evaluate arterial stiffness in patients with BD by using noninvasive radiological methods such as carotid artery intima-media thickness (CIMT), ankle-brachial pressure index (ABPI), coronary artery calcium score (CACaS), and their relation to serum fetuin-A levels, which was recently found to be important in vascular calcification.MethodsThis prospective study included 26 patients with BD and 25 control subjects. In all patients, the CIMT, ABPI, CACaS, and serum fetuin-A levels were examined.ResultsThe CIMT and CACaS were statistically higher and the ABPI was statistically lower in BD patients than in the control group. All p-values were <0.001. Positive correlations were found between the CACaS and CIMT, and negative correlations were found between the CACaS and ABPI. Although the values of fetuin-A were higher in BD, the difference was not statistically significant (p=0.064). However, the correlations found between fetuin-A levels and CIMT and between fetuin-A levels and CACaS were significant.ConclusionThe CIMT, CACaS, and ABPI are all useful in detecting structural and functional vascular damage in BD.

Evaluation of arterial stiffness in patients with coronary atherosclerosis, cardiac syndrome X and systemic lupus erythematosus (RCD code: I-3C.1)

Objectives: Arterial stiffness manifested by high pulse wave velocity (PWV) consists a risk factor of atherosclerosis and cardio-vascular complications. Systemic lupus erythematosus (SLE) is a generalized autoimmune disease in which patients’ prognosis depends contemporarily, in the corticosteroid era, mainly on the progression of premature atherosclerosis. The aim of the study was to assess arterial stiffness in patients with coronary atherosclerosis (CA), cardiac syndrome X (CSX) and SLE. Materials and methods: 44 CSX patients (28 females and 16 males; mean age 55,7; arterial hypertension in 32), 44 CA patients (19 females and 25 males; mean age 61,3; arterial hypertension in 41), 29 SLE patients (25 females and 4 males; mean age 37,4; arterial hypertension in 7), 29 control group (CG) patients. PWV was measured with use of SphygmoCor in all patients. Results: Patients with CSX had significantly lower PWV (9,63±1,69 m/s) as compared to CA patients (11,53±2,19 m/s) and significantly higher as compared to CG (8,07±1,03m/s) patients. The results of PWV in CSX and SLE patients (8,87±2,1 m/s) were similar. PWV increased with age and blood pressure in all groups. Diabetes mellitus and smoking caused PWV increase only in CA patients. Inflammatory markers didn’t influence PWV among patients with CA, CSX and SLE. Conclusions: Patients with CA have the highest arterial stiffness and significantly higher peripheral and central blood pressure. In SLE patients arterial stiffness is higher as compared to control group and similar as compared to the older CSX group. Diabetes mellitus and smoking increase arterial stiffness among CA patients. The prognostic value of PWV decrease in SLE patients should be addressed in large prospective clinical trials. JRCD 2015; 2 (2): 9–17

Plastic Optical Fiber Sensor for Noninvasive Arterial Pulse Waveform Monitoring

Central arterial pulse pressure monitoring has been considered a key factor in hypertension assessment and cardiovascular prevention. In this paper, it is presented an intensity-based plastic optical fiber sensor for noninvasive monitoring of the carotid pulse waveform. The advantages of this sensing method are the low implementation cost, high robustness, and the signal processing simplicity. The sensor showed a suitable sensitivity to movements up to 370 μm, with a displacement resolution of 0.1 μm. As preliminary proof of concept, the sensor was used to detect the arterial pulse waveform in some human subjects, allowing the assessment of key indexes for heart and arterial stiffness evaluation, such as augmentation index, subendocardial viability ratio, and ejection duration.

Association between Ophthalmological Changes and Cardiovascular Diseases in Patients with Chronic Kidney Disease Undergoing Hemodialysis.

Patients with chronic kidney disease (CKD) undergoing hemodialysis (HD) have a high prevalence of cardiovascular diseases (CVD). Arterial sclerosis plays an important role in the pathogenesis of CVD. However, to date, there have been no reports of assessment of the association between retinal arterial sclerosis and CVD in patients with CKD on HD. The aim of this study was to assess retinal arterial sclerosis and to investigate the relationship between retinal arterial changes in patients with CKD on HD and arterial stiffness/past history of CVD. We examined the data of 44 patients (21 female, 23 male) with CKD receiving HD treatment at Saiseikai Kurihashi Hospital. The relationship between ophthalmological changes and arterial stiffness [pulse wave velocity (PWV)] or past history of CVD was evaluated. All medications being taken were recorded, and biochemical parameters were analyzed. Significant correlations were found between the presence of arteriosclerotic retinopathy [Scheie classification S grade (grade 0: 7 patients, grade 1: 18 patients, grade 2: 14 patients, grade 3: 4 patients, and grade 4: 1 patient)] and results of the evaluation of arterial stiffness (PWV) and past history of CVD (p=0.001, p=0.045). Other ophthalmological findings were not associated with a history of CVD or arterial stiffness. We showed that the classification (Scheie S grade) of retinopathy on ophthalmoscopic examination may be a useful tool for predicting arterial stiffness and its association with CVD.

Technical Validation of ARTSENS-An Image Free Device for Evaluation of Vascular Stiffness.

Vascular stiffness is an indicator of cardiovascular health, with carotid artery stiffness having established correlation to coronary heart disease and utility in cardiovascular diagnosis and screening. State of art equipment for stiffness evaluation are expensive, require expertise to operate and not amenable for field deployment. In this context, we developed ARTerial Stiffness Evaluation for Noninvasive Screening (ARTSENS), a device for image free, noninvasive, automated evaluation of vascular stiffness amenable for field use. ARTSENS has a frugal hardware design, utilizing a single ultrasound transducer to interrogate the carotid artery, integrated with robust algorithms that extract arterial dimensions and compute clinically accepted measures of arterial stiffness. The ability of ARTSENS to measure vascular stiffness in vivo was validated by performing measurements on 125 subjects. The accuracy of results was verified with the state-of-the-art ultrasound imaging-based echo-tracking system. The relation between arterial stiffness measurements performed in sitting posture for ARTSENS measurement and sitting/supine postures for imaging system was also investigated to examine feasibility of performing ARTSENS measurements in the sitting posture for field deployment. This paper verified the feasibility of the novel ARTSENS device in performing accurate in vivo measurements of arterial stiffness. As a portable device that performs automated measurement of carotid artery stiffness with minimal operator input, ARTSENS has strong potential for use in large-scale screening.

Evaluation of affective temperaments and arterial stiffness in treated hypertensive patients

Evaluation of affective temperaments and arterial stiffness in treated hypertensive patients

Effects of renal denervation on end organ damage in hypertensive patients.

Renal denervation (RDN) is believed to reduce sympathetic nerve activity and is a potential treatment for resistant hypertension. The present study investigated the effects of RDN on end organ damage (EOD). The present study was a prospective cohort study (registered as NCT01427049). Uncontrolled hypertensive patients underwent a work-up prior to and one year after RDN. Cardiac magnetic resonance (CMR) imaging was used to determine left ventricular (LV)-mass; pulse wave analysis and pulse wave velocity (PWV) were used for evaluation of central blood pressure (BP) and arterial stiffness and 24-hour urine was collected for assessment of urinary albumin excretion. The 24-hour ambulatory BP measurement (ABPM) was used to evaluate the effect of RDN on BP. Fifty-four patients gave informed consent for study participation. Mean age was 58 ± 10 years, 50% were male. One year after RDN, mean ABPM decreased by 7 ± 18/5 ± 11 mm Hg (p = 0.01/p < 0.01). In the patients followed-up in a standardised fashion ABPM decreased by 5 ± 18/4 ± 12 mm Hg (n = 34; p = 0.11/p = 0.09). Mean body surface area indexed LV-mass decreased by 3.3 ± 11.5 g/m(2) (corresponding to a 3 ± 11% reduction; p = 0.09). PWV increased by 2.9 (-2.2 to +6.1) m/s (p = 0.04). Augmentation index corrected for 75 beats per min did not change (median increase 3.0 (-7 to +17) mm Hg; p = 0.89). Urinary albumin excretion did not change during follow-up (mean decrease 10 ± 117 mg/24 hour; p = 0.61). In the current study, we observed a modest effect from renal denervation. Moreover, RDN did not result in a statistical significant effect on end organ damage 12 months after treatment.

Arterial stiffness as a cardiovascular events risk marker and possibilities for its downregulation by contemporary antihypertensive medications

Arterial blood pressure measured by Korotkov’s method is a non-valid predictor for possible cardiovascular events, which requires introduction of new methods of arterial hypertension diagnostics. Recently, the effect on arterial stiffness has become a very important characteristic of antihypertensive drugs overall efficacy. Evaluation of arterial stiffness (central aortic pressure, augmentation index and pulse wave velocity) contributes to more precise cardiovascular risk stratification and reflects target organ damage and the effectiveness of antihypertensive treatment. In particular, pulse wave velocity exceeding 12 m/s is a significant risk factor of cardiovascular events. Arterial compliance can be determined by applanation tonometry, pulse wave shift at the carotid and femoral arteries, finger photoplethysmography, volume pulsoxymetry, echo-tracking, suprasystolic pulse waves recording method and cardio-ankle vascular index. Different effects of antihypertensive drugs on arterial stiffness at the same blood pressure reduction have been repeatedly shown. The article discusses the impact of the most commonly used antihypertensive drugs, including contemporary antihypertensive drugs combinations, on arterial stiffness. Effect of beta-blockers greatly varies depending on the characteristics of the drug, diuretics have neutral effect, calcium antagonists (especially amlodipine) decrease the pulse wave speed and arterial wall stiffness. Both angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers (more data for enalapril, perindopril and valsartan) were effective in decreasing arterial wall stiffness. A significant reduction in arterial wall stiffness was mainly found if antihypertensive drugs combinations were used, especially the combination of calcium antagonists and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers.

Association of arterial stiffness and cardiovascular system remodeling in patients with hypertension

Aim. To study the indices of arterial wall local stiffness and it association with structural and functional parameters of cardiovascular system remodeling in hypertensive patients. Methods. Cross-sectional population study included 213 industrial workers, among them 106 patients with stage I-II hypertension and 107 healthy individuals. The stage of arterial hypertension and additional cardiovascular risk category was performed in accordance with national guidelines. All patients underwent echocardiography, carotid arteries ultrasonography, including arterial stiffness evaluation. Results. In patients with hypertension, significant association of arterial wall stiffness indices and «intima-media» complex thickness (total impact of 91%) and echocardiographic parameters describing the left heart chambers volume were revealed. The fact of identifying the relatively high rate of altered arterial wall stiffness parameters, as well as its association with «intima-media» complex thickness in healthy individuals with normal blood pressure (total impact of 81%) may suggest that vascular wall rigidity change may premise vascular remodeling. Conclusion. Arterial wall stiffness indices may be a marker of effective control of risk factors in individuals with normal blood pressure and effect of drug therapy in patients with hypertension.

Ultrasound signal quality parameterization for image-free evaluation of arterial stiffness.

We are in process of developing an image-free, single element ultrasound system for automated evaluation of arterial stiffness, we call it ARTSENS. The lack of a guiding image for arterial visualization necessitates intelligent analysis of ultrasound radio frequency (RF) echo signals to obtain reliable measurements. In this paper, we propose a novel algorithm to parameterize the echo signal received from the common carotid artery (CCA) to improve accuracy and reliability of arterial stiffness measurement. The echo signal quality is parameterized using features such as sharpness of arterial wall and energy ratio. A signal quality score is calculated by integrating the results from each feature. This score is used to triage the set of available echo signals recorded from each subject and select the best signal for computation of stiffness values. The performance of signal quality algorithm is tested using a database of carotid artery echo signals recorded from 28 human volunteers. It was observed that both the accuracy and reliability of the stiffness measurements were improved after triaging using the signal quality parameterization algorithm.

Image-free evaluation of carotid artery stiffness using ARTSENS: a repeatability study.

Evaluation of arterial stiffness is significant in early detection and vascular diagnosis. We have developed and validated an image free system called ARTSENS for evaluation of carotid artery stiffness. In this paper, we present a detailed study on the repeatability of arterial stiffness measurements performed using ARTSENS. The study protocol was designed to emulate typical constraints encountered in field usage of ARTSENS as a screening tool. The intra operator variability (repeatability) of ARTSENS was verified by in-vivo measurements on 18 subjects. Inter operator variability (reproducibility) was also studied. The ability of the instrument to give reliable measurements in both sitting and supine posture of the subject was verified. Further, the variation of arterial stiffness measurements over different times of the day was investigated to verify the ability of the instrument to give a practically usable stable measure of stiffness. The repeatability and reproducibility of ARTSENS measurements was found to be comparable to those provided by state of art image-based systems. Stiffness measurements provided by ARTSENS were found to be stable over a day indicating utility of the instrument in providing a quick and reliable measure of carotid artery stiffness.