Mechanical Characterization of Individual Needles in Microneedle Arrays: Factors Affecting Compression Test Results.

This study aims to investigate the impact of test conditions on the results of the compression testing of microneedle arrays (MNAs). Uniaxial compression tests were conducted on polyglycolic acid-fabricated biodegradable MNAs. Load-displacement curves were obtained for varying conditions, including the number of microneedles (MNs) compressed simultaneously, compression speeds, and compression angles.

Hemodynamics with mechanical circulatory support devices using a cardiogenic shock model.

Mechanical circulatory support (MCS) devices, including veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and Impella, have been widely used for patients with cardiogenic shock (CS). However, hemodynamics with each device and combination therapy is not thoroughly understood. We aimed to elucidate the hemodynamics with MCS using a pulsatile flow model.

A tissue-silicone integrated simulator for right ventricular pulsatile circulation with severe functional tricuspid regurgitation.

There is a great demand for development of a functional tricuspid regurgitation (FTR) model for accelerating development and preclinical study of tricuspid interventional repair devices. This study aimed to develop a severe FTR model by creating a tissue-silicone integrated right ventricular pulsatile circulatory simulator. The simulator incorporates the porcine tricuspid annulus, valve leaflets, chordae tendineae, papillary muscles, and right ventricular wall as one continuous piece of tissue, thereby preserving essential anatomical relationships of the tricuspid valve (TV) complex.

Lipid index to quantify the absorbed lipids in retrieved UHMWPE components of joint arthroplasty.

Background: The ultra-high molecular weight polyethylene (UHMWPE) component of artificial joints is one of the most important factors affecting the clinical outcomes of joint arthroplasty. Although the possibility of in vivo UHMWPE degradation caused by absorbed lipids has been reported, a quantitative evaluation of this phenomenon has not yet been performed.

Objective: This study aimed to establish the lipid index (LI) as a quantitative indicator of the amount of absorbed lipids and the first step to quantify their effects on UHMWPE.

Importance of optimal rewiring guided by 3-dimensional optical frequency domain imaging during double-kissing culotte stenting demonstrated through a novel bench model.

The usefulness of optical frequency domain imaging (OFDI) guidance on two-stenting at left main bifurcation has not been evaluated. Here, we used a novel bench model to investigate whether pre-defined optimal rewiring with OFDI-guidance decreases acute incomplete stent apposition (ISA) at the left main bifurcation segment. A novel bench simulation system was developed to simulate the foreshortening and overlapping of daughter vessels as well as left main bifurcation motion under fluoroscopy.

Biaxial tensile testing system for measuring mechanical properties of both sides of biological tissues.

The aortic wall exhibits a unique elastic behavior, periodically expanding in aortic diameter by approximately 10% during heartbeats. This elastic behavior of the aortic wall relies on the distinct yet interacting mechanical properties of its three layers: intima, media, and adventitia. Aortic aneurysms develop as a result of multifactorial remodeling influenced by mechanical vulnerability of the aortic wall.

Latest outcomes of transcatheter left atrial appendage closure devices and direct oral anticoagulant therapy in patients with atrial fibrillation over the past 5 years: a systematic review and meta-analysis.

Left atrial appendage closure (LAAC) are emerging treatment for patients with atrial fibrillation (AF). However, data on the safety, efficacy, and medications for LAAC devices in patients with AF are lacking. We aimed to investigate the incidence of all-cause mortality, stroke, and major bleeding in AF patients with LAAC devices and DOACs.

Comprehensive Risk Analysis of the Wingspan Stent in Relation to Target Vessels.

Objective: To facilitate understanding for the safe use of the Wingspan stent, a comprehensive literature analysis was conducted, and incidence rates of 30-day stroke or death before and after the Stenting versus Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial were compared. We also investigated the associations between 30-day stroke or death rate and four lesion vessels, the internal carotid artery (ICA), middle cerebral artery (MCA), basilar artery (BA), and vertebral artery (VA).

Methods: We searched MEDLINE, Embase, Web of Science, and Cochrane Library databases.

The stability of flow velocity and intracoronary resistance in the intracoronary electrocardiogram-triggered pressure ratio.

Assessment of coronary artery lesions using the fractional flow reserve and instantaneous flow reserve (iFR) measurements has been found to reduce the incidence of further cardiovascular events. Here, we investigated differences in terms of coronary flow velocity and resistance within the analysis interval between the iFR and the intracoronary electrocardiogram (IC-ECG)-triggered distal/aortic pressure (Pd/Pa) ratio (ICE-T). We enrolled 23 consecutive patients (n = 33 stenoses) who required coronary flow measurements.

Reflected wave intensity increases based on aortic diameter after endovascular aortic therapy in a goat model.

Reflected wave increases after endovascular aortic repair (EVAR) in patients with aortic aneurysm. This affects the left ventricular (LV) diastolic function and leads to a poor prognosis. This study aimed to evaluate the relationship between increased reflected wave amplitude and aortic diameter after EVAR.

Impact of age on left ventricular geometry and diastolic function in elderly patients with treated hypertension.

Purpose: Left ventricular (LV) remodelling is observed in numerous patients with hypertension and is a principal cause of heart failure in elderly patients. The aim of this study was to determine the relationships between age and structural/functional LV remodelling observed in elderly hypertensive patients.

Methods: A total of 557 elderly hypertensive patients (mean age: 74.

Engineering based assessment for a shape design of a pediatric ePTFE pulmonary conduit valve.

The authors examined the hemodynamic characteristics of expanded polytetrafluoroethylene (ePTFE) pulmonary valved conduits quantitatively by our originally developed pediatric pulmonary mechanical circulatory system, in order to suggest the optimal shape design. The system consisted of pneumatically driven right atrium and ventricle model, a pulmonary valve chamber, and elastic pulmonary compliance model with peripheral vascular resistance units, a venous reservoir. We employed two different types of ePTFE valve and evaluated the relationship between the leaflets motion and hemodynamic characteristics by using a high-speed video camera.

Effect of valsalva in the pulmonary prosthetic conduit valve on hemodynamic function in a mock circulatory system.

Pulmonary conduit valves are used as one of the surgical treatment methods of congenital heart diseases. We have been designing a sophisticated pulmonary conduit valve for the right ventricular outflow tract reconstruction in pediatric patients. In this study, two types of polyester grafts with or without bulging structures for the conduit valves were used and evaluated from the hemodynamic point of view focusing on the application of these conduit valves in the grown-up congenital heart failure patients.

Hemodynamics of a functional centrifugal-flow total artificial heart with functional atrial contraction in goats.

Implantation of a total artificial heart (TAH) is one of the therapeutic options for the treatment of patients with end-stage biventricular heart failure. There is no report on the hemodynamics of the functional centrifugal-flow TAH with functional atrial contraction (fCFTAH). We evaluated the effects of pulsatile flow by atrial contraction in acute animal models.

Development of a thermodynamic control system for the Fontan circulation pulsation device using shape memory alloy fibers.

The Fontan procedure is one of the common surgical treatments for circulatory reconstruction in pediatric patients with congenital heart disease. In Fontan circulation, low pulsatility may induce localized lung ischemia and may impair the development of pulmonary peripheral endothelial cells. To promote pulmonary circulation in Fontan circulation, we have been developing a pediatric pulmonary circulatory pulsation device using shape memory alloy fibers attached from the outside of total cavopulmonary connection.

Hemodynamic effects of pressure-volume relation in the atrial contraction model on the total artificial heart using centrifugal blood pumps.

Hemodynamic effects of atrial contraction with centrifugal pump type total artificial heart is unknown. In this study, we simulated an atrial contraction in a mock model. By the driving condition with higher pressure in the mock atrial model, the load during atrial contraction increased.

Nocturnal Blood Pressure Pattern Affects Left Ventricular Remodeling and Late Gadolinium Enhancement in Patients with Hypertension and Left Ventricular Hypertrophy.

Background: Left ventricular hypertrophy (LVH) is an independent predictor of cardiac mortality, regardless of its etiology. Previous studies have shown that high nocturnal blood pressure (BP) affects LV geometry in hypertensive patients. It has been suggested that continuous pressure overload affects the development of LVH, but it is unknown whether persistent pressure influences myocardial fibrosis or whether the etiology of LVH is associated with myocardial fibrosis.

Engineering analysis of the effects of bulging sinuses in a newly designed pediatric pulmonary heart valve on hemodynamic function.

The purpose of this study was to examine the hemodynamic characteristics of expanded polytetrafluoroethylene (ePTFE) pulmonary valves with bulging sinuses quantitatively in a pediatric pulmonary mechanical circulatory system designed by us, in order to propose the optimal design for clinical applications. In this study, we developed a pediatric pulmonary mock circulation system, which consisted of a pneumatic right ventricular model, a pulmonary heart valve chamber, and a pulmonary elastic compliance tubing with resistive units. The hemodynamic characteristics of four different types of ePTFE valves and a monoleaflet mechanical heart valve were examined.

[Suppressive effect of nicorandil in ventricular arrhythmias after reperfusion therapy in patients with acute myocardial infarction].

Background: Nicorandil is reported to inhibit reperfusion arrhythmias in patients with acute myocardial infarction (AMI), but few studies have counted ventricular arrhythmias with Holter electrocardiograms in patients treated with nicorandil following AMI reperfusion.

Objectives: In the present study, we examined the effects of nicorandil by investigating the occurrence of ventricular arrhythmia with Holter electrocardiogram monitoring after percutaneous coronary intervention with acute myocardial infarction.

Methods: Forty patients with AMI who underwent successful percutaneous coronary intervention (PCI) were enrolled and randomly assigned to nicorandil or placebo groups.