Structural health monitoring (SHM) is crucial for ensuring operational safety in applications like pipelines, tanks, aircraft, ships, and vehicles. Traditional embedded sensors have limitations due to expense and potential structural damage. A novel technology using radio frequency identification devices (RFID) offers wireless transmission of highly sensitive strain measurement data.
View Article and Find Full Text PDFStrain mapping over a large area usually requires an array of sensors, necessitating extensive and complex wiring. Our solution is based on creating multiple sensing regions within the area of a single capacitive sensor body by considering the sensor as an analogical transmission line, reducing the connections to only two wires and simplifying the electronic interface. We demonstrate the technology by using piezoresistive electrodes in a parallel plate capacitor that create varying proportions of electromagnetic wave dissipation through the sensor length according to the interrogation frequency.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2021
Accurate wireless strain monitoring is critical for many engineering applications. Capacitive strain sensors are well suited for remote sensing but currently have a limited sensitivity. This study presents a new approach for improving the sensitivity of electrical capacitance change-based strain sensors.
View Article and Find Full Text PDFUsing new satellite observations and atmospheric inverse modeling, we report methane emissions from the Permian Basin, which is among the world's most prolific oil-producing regions and accounts for >30% of total U.S. oil production.
View Article and Find Full Text PDFCorrection for 'Towards wireless highly sensitive capacitive strain sensors based on gold colloidal nanoparticles' by H. Nesser et al., Nanoscale, 2018, DOI: 10.
View Article and Find Full Text PDFWe designed, produced and characterized new capacitive strain sensors based on colloidal gold nanoparticles. The active area of these sensors, made up of a 1 mm2 close-packed assembly of gold nanoparticles between interdigitated electrodes, was designed to achieve measurable capacitance (>∼1 pF) and overcome parasitic capacitances. Electro-mechanical experiments revealed that the sensitivity of such capacitive sensors increases in relation to the size of the nanoparticles.
View Article and Find Full Text PDFEur Heart J Acute Cardiovasc Care
October 2016
Background: The Tako-Tsubo syndrome is still rarely diagnosed in patients presenting with symptoms of acute myocardial ischaemia. It is accompanied by wall motion abnormalities of the left ventricle but significant narrowings or occlusions of epicardial coronary arteries are absent. We investigated a potential relationship between electrocardiogram (ECG) changes, wall motion abnormalities and gender influence of Tako-Tsubo syndrome in an Austrian cohort of Tako-Tsubo syndrome patients.
View Article and Find Full Text PDFBackground: Sufficient electrode-tissue contact is crucial for adequate lesion formation in radiofrequency catheter ablation (RFCA).
Objective: We assessed the impact of direct catheter force measurement on acute procedural parameters and outcome of RFCA for paroxysmal and persistent atrial fibrillation (AF).
Methods: Ninety-nine consecutive patients (70% men) with paroxysmal (63.
Aims: Three-dimensional (3D) speckle tracking echocardiography (3DSTE) has been shown to be an accurate and reliable clinical tool for the evaluation of global and regional left ventricular (LV) function through strain analysis, but the absence of normal values has precluded its widespread use in clinical practice. The aim of this prospective multicentre study was to establish normal reference values of LV strain parameters using 3DSTE in a large healthy population.
Methods And Results: A total of 303 healthy subjects (156 males [51%], between 18 and 82 years of age, ejection fraction [EF] 61 ± 3%), stratified to provide approximately equal proportions of healthy subjects of 18-30, 31-40, 41-50, 51-60, and >60 years of age, underwent 3DSTE.
Eur Heart J Acute Cardiovasc Care
June 2013
Background: Tako-Tsubo syndrome (TS) is a still rarely diagnosed clinical syndrome, which is characterized by acute onset of chest pain, transient cardiac dysfunction with (frequently) reversible wall motion abnormalities (WMAs), but with no relevant obstructive coronary artery disease.
Methods And Results: Among 179 consecutive patients with proven diagnosis of TS that were retrospectively analysed in this multicentre registry, women represented the majority of patients (94%) while only 11 men (6%) developed TS. Mean age was 69.
Clin J Am Soc Nephrol
December 2013
Background And Objectives: Sequential echocardiography is routinely performed in patients with ESRD listed for transplantation. The benefit of this labor- and time-intensive measure, however, remains unclear. Thus, this study elucidated the various obtained routine echocardiography parameters that best predicted mortality and graft survival after renal transplantation.
View Article and Find Full Text PDFAims: Left atrial radiofrequency ablation has been shown to carry a risk of asymptomatic cerebral lesions. No data exist in patients under continued oral anticoagulation during the ablation procedure. The aim of this study was to quantify the amount of silent cerebral lesions assessed by pre-procedural and post-procedural magnetic resonance imaging (MRI) in patients under therapeutic international normalized ratio (INR) and to identify clinical or procedural parameters that correlate with cerebral embolism.
View Article and Find Full Text PDFBackground: Electrode-tissue contact is crucial for adequate lesion formation in radiofrequency catheter ablation (RFCA).
Objective: We assessed the impact of direct catheter force measurement on acute procedural parameters during RFCA of atrial fibrillation (AF).
Methods: Fifty consecutive patients (28 male) with paroxysmal AF who underwent their first procedure of circumferential pulmonary vein (PV) isolation (PVI) were assigned to either RFCA using (1) a standard 3.
Objectives: We studied in a multicenter setting the accuracy and reproducibility of 3-dimensional echocardiography (3DE)-derived measurements of left atrial volume (LAV) using new, dedicated volumetric software, side by side with 2-dimensional echocardiography (2DE), using cardiac magnetic resonance (CMR) imaging as a reference.
Background: Increased LAV is associated with adverse cardiovascular outcomes. Although LAV measurements are routinely performed using 2DE, this methodology is limited because it is view dependent and relies on geometric assumptions regarding left atrial shape.
Background: Assessment of right ventricular (RV) function is difficult due to the complex shape of this chamber. Tricuspid annular plane systolic excursion (TAPSE) measured with M-mode echocardiography is frequently used as an index of RV function. However, its accuracy may be limited by ultrasound beam misalignment.
View Article and Find Full Text PDFVentricular preexcitation caused by right-sided accessory pathways can lead to abnormal septal motion patterns and may be associated with left ventricular (LV) dysfunction and heart failure, despite the lack of a clinical arrhythmia. Hence successful ablation of the accessory pathway abolishes not only preexcitation but also ventricular dyssynchrony in these patients. We describe a case of an asymptomatic 20-year-old male presenting with ventricular Type-B preexcitation combined with LV dysfunction.
View Article and Find Full Text PDFPurpose: Left ventricular (LV) remodeling is usually assessed using global changes in LV volume. We hypothesized that three-dimensional analysis of regional endocardial curvature from magnetic resonance images could provide clinically useful information on localized LV remodeling. We tested this approach by investigating regional differences in endocardial curvature in normal and hypokinetic ventricles.
View Article and Find Full Text PDFHerzschrittmacherther Elektrophysiol
March 2011
Ischemic heart disease is characterized by hemodynamic adaptations and an increased risk of ventricular arrhythmias. Frequent premature ventricular complexes (PVCs) have been associated with ventricular reentry arrhythmias and can promote the worsening of left ventricular function. This case report discusses the beneficial effects of catheter ablation of frequent premature ventricular complexes originating remote from the healed myocardial infarction scar in the treatment of progressive heart failure.
View Article and Find Full Text PDFChallenges encountered during catheter ablation of ventricular tachycardia (VT) include hemodynamic instability and lack of inducibility. Recent approaches guided by electroanatomic mapping demonstrated the feasibility of VT ablation during sinus rhythm. We analyzed the data from 40 consecutive patients who were referred to the Elisabethinen Hospital Linz for VT ablation.
View Article and Find Full Text PDFHerzschrittmacherther Elektrophysiol
September 2010
The population of adults with surgically corrected tetralogy of Fallot (TOF) is increasing. Atrial and ventricular arrhythmias are prevalent, and therapeutical approaches including implantable cardioverter-defibrillators and radiofrequency catheter ablation need to be considered carefully for the prevention of hemodynamic deterioration and sudden cardiac death. Complex anatomy, myocardial hypertrophy, and broad channels of slow conduction may in part explain some challenges regarding risk stratification, and identification/modification of the arrhythmogenic substrate in these patients.
View Article and Find Full Text PDFAims: The Speckle Tracking and Resynchronization (STAR) study used a prospective multi-centre design to test the hypothesis that speckle-tracking echocardiography can predict response to cardiac resynchronization therapy (CRT).
Methods And Results: We studied 132 consecutive CRT patients with class III and IV heart failure, ejection fraction (EF) < or =35%, and QRS > or =120 ms from three international centres. Baseline dyssynchrony was evaluated by four speckle tracking strain methods; radial, circumferential, transverse, and longitudinal (> or =130 ms opposing wall delay for each).
The authors summarize the recent developments in speckle-tracking echocardiography (STE), a relatively new technique that can be used in conjunction with two-dimensional or three-dimensional echocardiography for resolving the multidirectional components of left ventricular (LV) deformation. The tracking system is based on grayscale B-mode images and is obtained by automatic measurement of the distance between 2 pixels of an LV segment during the cardiac cycle, independent of the angle of insonation. The integration of STE with real-time cardiac ultrasound imaging overcomes some of the limitations of previous work in the field and has the potential to provide a unified framework to more accurately quantify the regional and global function of the left ventricle.
View Article and Find Full Text PDFBackground: Atrioesophageal fistula is an uncommon but life-threatening complication of atrial fibrillation (AF) ablation. Esophageal ulcerations (ESUL) have been proposed to be potential precursor lesions.
Objective: The purpose of our study was to prospectively investigate the incidence of ESUL in a large patient population undergoing radiofrequency catheter ablation (RFA).
JACC Cardiovasc Imaging
January 2010
Objectives: We undertook volumetric analysis of the right ventricle (RV) by real-time 3-dimensional echocardiography (RT3DE), cardiac magnetic resonance (CMR), and cardiac computed tomography (CCT) on images obtained in RV-shaped phantoms and in patients with a wide range of RV geometry.
Background: Assessment of the RV by 2-dimensional (2D) echocardiography remains challenging due to its unique geometry and limitations of the current analysis techniques. RT3DE, CMR, and CCT, which can quantify RV volumes, promise to overcome the limitations of 2D echocardiography.