Dynamic analysis of a warp-knitting machine with pneumatic drive for producing 3D knitted fabrics

The paper reports the construction of a warp-knitting machine for spatial knitted fabrics and a dynamic model of its basic working unit – the arrangement of a whip roller and a slider with a guide needle bar. The concept of the machine is based on a positive feeding of the knitting zone, with a little correction from the warp tension, and a rectilinear movement of the guide needle bars by using pneumatic drive. The paper also presents the results of dynamic analysis of the system movement. The influence of the dynamic parameters of the whip roller on the possibility of executing a work cycle with a certain efficiency has been determined. Dynamic load of the warp thread during the cycle is also tested. For the analyzed structure of the machine it has been established that the duration of a single cycle cannot be shorter than 0.2 s

Contrast-enhanced ultrasonography versus computed tomographic angiography in the monitoring of patients after endovascular repair of abdominal aortic aneurysm - preliminary experience

BACKGROUND: Computed tomographic angiography (CTA) is routinely used in the monitoring of patients after endovascular repair of abdominal aortic aneurysm. The aim of the study was to determine if contrast-enhanced ultrasonography (CEUS) provides equivalent results to CTA in detection of endo-leaks in patients after abdominal aortic stentgraft placement. MATERIAL AND METHODS: In a group of 7 patients (6 men and 1 woman; aged 71±7 years) after repair procedure, 16 CTA and 16 CEUS follow-up examinations were performed. Second-generation contrast agent (Sonovue) and low-mechanical index technique were used for ultrasonography imaging. RESULTS: Computed tomographic angiography showed seven cases of type I, five cases of type II, and no endo-leaks in four examinations. In 15 out of 16 studies, the results of CEUS were consistent with the results of CTA. In one discrepant study, type II endo-leak was detected with CEUS while CTA was negative. CONCLUSIONS: Contrast-enhanced ultrasonography and CTA examinations in patients after endovascular repair of abdominal aortic aneurysm provide comparable results. CEUS may be considered an alternative technique to CTA

UHECR Anisotropy from Luminous Infrared Galaxies - Predictions for the Pierre Auger Observatory

Abstract We consider the hypothesis that luminous infrared galaxies (LIRGs) are sources of the UHECRs. By associating the AGASA triplet with the Arp 299 galaxy we obtain reasonable values for Galactic and extragalactic magnetic fields. We predict what the southern sky, to be seen by the Auger experiment, should look like, so that the LIRG hypothesis could be verified soon

Effectiveness of Medtronic CareLink Express System in identifying patients with high-energy electrotherapy devices requiring clinically significant intervention

   Background: The number of patients with implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy and defibrillator (CRT-D) is growing. This results in high workloads for centers performing standard controls (SC) of these systems. Medtronic CareLink Express® (MCLE) is a solution enabling remote controls (RC) of implantable devices. In cases of detecting arrhythmias or device malfunctioning, it automatically generates alarms transmitted to the controlling physician. The objective of the study was to evaluate the effectiveness of alarms generated by MCLE in identification of patients that require clinically significant intervention during SC. Methods: A total of 119 patients (age 64 ± 14, 17 women) implanted with ICD/CRT-D were included in the trial. Device reprogramming or pharmacological treatment modifications during SC were as­sessed as significant if they were required for optimal clinical management of the patient (effectiveness of antiarrhythmic and resynchronization therapy, also patient safety). Analysis of generated alarms was then performed to assess the effectiveness (sensitivity and specificity) of MCLE in identifying patients that require changes in therapy. Results: Data from 129 transmissions and 129 subsequent SCs were analyzed. 179 alarms were recorded during 96 (74%) transmissions. A total of 333 program changes of implanted devices took place during 107 (83%) SCs. Device reprogramming was considered clinically significant in 27 cases Additionaly, 13 pharmacological treatment modifications were performed. Sensitivity and specificity of alarms generated by MCLE with regards to identification of patients requiring clinically significant intervention was 87% and 31%, respectively. Finally, a statistically significant difference was observed in the number of clinically significant interventions among patients with and without MCLE alarms (33 [86.8%] vs. 5 [13.2%], p = 0.037). Conclusions: Medtronic CareLink Express® is an RC system enabling high-sensitivity supervision of patients with cardia

One center experience in pulmonary artery stenting without long vascular sheath

Background: Pulmonary artery stenting without a long vascular sheath has a special significance, particularly for children with low body weight. Using only a short sheath often permits the implantion of a stent of the correct size; moreover, it improves access to peripherally located stenoses. The aim of this paper is to present the results of a balloon expandable stent implantation into pulmonary arteries without using a long vascular sheath. Methods: The subjects were divided into two groups. The first group (28 patients, mean age 3.2 years) comprised patients with a single-ventricle heart after bi-directional Glenn procedure (Fontan procedure). The second group (22 patients, mean age 8.3 years) consisted of patients with a two-ventricle heart. Patients were retrospectively analyzed with regard to stenosis size widening and change in trans-stenotic pressure gradient after stenting. Results: In our data, no statistically significant differences between the two groups in terms of the number of complications and incorrect stent position following implantation were noted (3% and 4%). Good treatment results, with a decrease in trans-stenotic pressure gradient in the first group of 3.2 mm and in the second group of 13.4 mm of mercury, and a widening of the stenosis, were obtained in most cases in both groups (97% and 96%). The average change of the vessel’s diameter was in the first group 4.2 mm and in the second 5.4 mm. Conclusions: The obtained results suggest that pulmonary artery stenting with a short vascular sheath has numerous advantages and can be successfully performed in children. In the case of single-ventricle hearts after a Glenn procedure, it may indeed be the method of choice. (Cardiol J 2010; 17, 2: 149-156

Subclinical target organ damage in patients with essential hypertension

W ostatnich dekadach dokonał się znaczący postęp w możliwościach oceny struktury i funkcji układu sercowo-naczyniowego, który u chorych z nadciśnieniem tętniczym pierwotnym umożliwił ocenę wczesnych zmian w obrębie serca i naczyń. Za najbardziej charakterystyczne zmiany w sercu w przebiegu nadciśnienia uważa się pogrubienie ścian, wzrost masy mięśnia lewej komory, przebudowę komory oraz dysfunkcję rozkurczową. Przyjmuje się, że u chorych z nadciśnieniem tętniczym pogrubienie błony wewnętrznej i środkowej oceniane najczęściej w obrębie tętnicy szyjnej poprzedza rozwój ogniskowych zmian miażdżycowych. Badania rozpoczęte na początku lat 90. ubiegłego wieku dostarczyły dowodów wskazujących na rozwój dysfunkcji śródbłonka w przebiegu nadciśnienia tętniczego. Mikroalbuminuria należy do najwcześniejszych objawów uszkodzenia nerek w przebiegu nadciśnienia i zaliczana jest do najważniejszych czynników ryzyka sercowo-naczyniowego. Wyniki dotychczasowych badań wskazują na związek mikroalbuminurii zarówno z klasycznymi, jak i nowo poznanymi czynnikami ryzyka.Assessment of subclinical target organ damage is a key element in the management of patients with hypertension. Impaired diastolic function and increased LV mass are common findings in hypertensive patients and may occur early in the natural history of hypertension. Ultrasonographic measurements of intima-media thickness (IMT) in carotid arteries are being applied extensively and have been regarded as a valid indicator of atherosclerosis. Several studies showed association between IMT and hypertensive target organ damage, cardiovascular events and risk factors. Microalbuminuria is a marker for generalized vascular dysfunction, is the earliest sign of nephropathy and predicts target organ damage, notably renal disease. Hypertensive patients with microalbuminuria had a significantly higher prevalence of CAD, LV hypertrophy, MI and stroke. The modern goal of the treatment of hypertension is to prevent progression, or even to reverse, subclinical target organ damage

Influence of echocardiographic and radiographic characteristics on atrial sensing amplitude in patients with Linox Smart S DX defibrillation leads

Background: Single-lead for implantable cardioverter-defibrillator (ICD) with floating atrial sensing dipole is a new diagnostic tool with the potential advantage in terms of arrhythmia discrimination. We sought to determine whether right heart size and dipole position influence atrial sensing. Methods: Atrial sensing (AS) amplitude was measured during implantation (PP, periprocedural), predischarge (IHFU, in-hospital follow-up) and 3–6 months after the procedure (AFU, ambulatory follow-up). Results were related to atrial dipole position in the right atrium (RA) on the basis of chest X-ray examination as well as right heart dimensions at echocardiography. Results: Twenty-four patients were included into final analysis. In 14 (58.3%) patients, sensing dipole was located in regions 1 and 2 of the RA. AS amplitude was greater in regions 1 and 2 when com¬pared to other locations (3.15 vs. 1.2 mV, p = 0.045, 7.53 vs. 3.8 mV, p < 0.001 and 5.63 vs. 2.44 mV, p = 0.017 for PP measurements, IHFU and AFU, respectively). There was a significant negative correlation between AS-PP and short RA dimension (RADs) (r = –0.56, p = 0.02), AS-IHFU and RA area (RAA) (r = –0.45, p < 0.05), AS-AFU and long RA dimension (RADl) (r = –0.46; p = 0.02), AS-AFU and RADs (r = –0,48, p = 0.02), and AS-AFU and RAA (and r = –0.52, p < 0.01). There was no relationship between AS and other right heart dimensions. Conclusions: Larger RA size and low sensing dipole location were associated with lower AS amplitude in single-lead dual chamber ICD