Can We Prevent Recurrent UTIs Without Antibiotics, in Both Those Who Do and Do Not Use Catheters? ICI-RS 2024.

Aims: Urinary tract infections are one of the most common reasons for antibiotic prescription. The widespread use of antibiotic treatments contributes to the global health problem of antimicrobial resistance development. To slow down the progression of antimicrobial resistance, it is essential that we explore nonantibiotic preventive treatments for this common condition.

Innovating Indwelling Catheter Design to Counteract Urinary Tract Infection.

Background And Objective: Bacteriuria is anticipated in long-term indwelling catheter (IDC) use, and urinary tract infections (UTIs) and related issues are common. Defence mechanisms against infection are undermined by the presence of a Foley catheter, and adjustments to design could influence UTI risk.

Methods: We reviewed the various aspects of IDCs and ureteric stent designs to discuss potential impact on UTI risk.

Novel para-aortic cardiac assistance using a pre-stretched dielectric elastomer actuator.

Objectives: We propose an evolution of a dielectric elastomer actuator-based cardiac assist device that acts as a counterpulsation system. We introduce a new pre-stretched actuator and implant the device in a graft bypass between the ascending and descending aorta to redirect all blood through the device (ascending aorta clamped). The objective was to evaluate the influence of these changes on the assistance provided to the heart.

Is the time right for a new initiative in mathematical modeling of the lower urinary tract? ICI-RS 2023.

Introduction: A session at the 2023 International Consultation on Incontinence - Research Society (ICI-RS) held in Bristol, UK, focused on the question: Is the time right for a new initiative in mathematical modeling of the lower urinary tract (LUT)? The LUT is a complex system, comprising various synergetic components (i.e., bladder, urethra, neural control), each with its own dynamic functioning and high interindividual variability.

Dielectric Elastomer Actuator-Based Valveless Impedance-Driven Pumping for Meso- and Macroscale Applications.

Impedance pumps are simple designs that allow the generation or amplification of flow. They are fluid-filled systems based on flexible tubing connected to tubing with different impedances. A periodic off-center compression of the flexible tubing causes the fluid to move and generate flow.

Hemodynamic effects of a dielectric elastomer augmented aorta on aortic wave intensity: An in-vivo study.

Dielectric elastomer actuator augmented aorta (DEA) represents a novel approach with high potential for assisting a failing heart. The soft tubular device replaces a section of the aorta and increases its diameter when activated. The hemodynamic interaction between the DEA and the left ventricle (LV) has not been investigated with wave intensity (WI) analysis before.

Fluid mechanical performance of ureteral stents: The role of side hole and lumen size.

Ureteral stents are indispensable devices in urological practice to maintain and reinstate the drainage of urine in the upper urinary tract. Most ureteral stents feature openings in the stent wall, referred to as side holes (SHs), which are designed to facilitate urine flux in and out of the stent lumen. However, systematic discussions on the role of SH and stent lumen size in regulating flux and shear stress levels are still lacking.

A novel soft cardiac assist device based on a dielectric elastomer augmented aorta: An in vivo study.

Although heart transplant is the preferred solution for patients suffering from heart failures, cardiac assist devices remain key substitute therapies. Among them, aortic augmentation using dielectric elastomer actuators (DEAs) might be an alternative technological application for the future. The electrically driven actuator does not require bulky pneumatic elements (such as conventional intra-aortic balloon pumps) and conforms tightly to the aorta thanks to the manufacturing method presented here.

Effect of Collateral Flow on Catheter-Based Assessment of Cardiac Microvascular Obstruction.

Cardiac microvascular obstruction (MVO) associated with acute myocardial infarction (heart attack) is characterized by partial or complete elimination of perfusion in the myocardial microcirculation. A new catheter-based method (CoFI, Controlled Flow Infusion) has recently been developed to diagnose MVO in the catheterization laboratory during acute therapy of the heart attack. A porcine MVO model demonstrates that CoFI can accurately identify the increased hydraulic resistance of the affected microvascular bed.

Fluid mechanical modeling of the upper urinary tract.

The upper urinary tract (UUT) consists of kidneys and ureters, and is an integral part of the human urogenital system. Yet malfunctioning and complications of the UUT can happen at all stages of life, attributed to reasons such as congenital anomalies, urinary tract infections, urolithiasis and urothelial cancers, all of which require urological interventions and significantly compromise patients' quality of life. Therefore, many models have been developed to address the relevant scientific and clinical challenges of the UUT.

Feasibility of a Dielectric Elastomer Augmented Aorta.

Although heart transplantation is a gold standard for severe heart failure, there is a need for alternative effective therapies. A dielectric-elastomer aorta is used to augment the physiological role of the aorta in the human circulatory system. To this end, the authors developed a tubular dielectric elastomer actuator (DEA) able to assist the heart by easing the deformation of the aorta in the systole and by increasing its recoil force in the diastole.

Local vs. Global Blood Flow Modulation in Artificial Microvascular Networks: Effects on Red Blood Cell Distribution and Partitioning.

Our understanding of cerebral blood flow (CBF) regulation during functional activation is still limited. Alongside with the accepted role of smooth muscle cells in controlling the arteriolar diameter, a new hypothesis has been recently formulated suggesting that CBF may be modulated by capillary diameter changes mediated by pericytes. In this study, we developed microvascular network models featuring a valve enabling the dilation of a specific micro-channel.

investigations of red blood cell phase separation in a complex microchannel network.

Microvascular networks feature a complex topology with multiple bifurcating vessels. Nonuniform partitioning () of red blood cells (RBCs) occurs at diverging bifurcations, leading to a heterogeneous RBC distribution that ultimately affects the oxygen delivery to living tissues. Our understanding of the mechanisms governing RBC heterogeneity is still limited, especially in large networks where the RBC dynamics can be nonintuitive.

Modulation of Bladder Wall Micromotions Alters Intravesical Pressure Activity in the Isolated Bladder.

Micromotions are phasic contractions of the bladder wall. During urine storage, such phasic activity has little effect on intravesical pressure, however, changed motile activity may underlie urodynamic observations such as detrusor overactivity. The potential for bladder motility to affect pressure reflects a summation of the overall movements, comprising the initiation, propagation, and dissipation components of micromotions.

Cardiac electrophysiology catheters for electrophysiological assessments of the lower urinary tract-A proof of concept ex vivo study in viable ureters.

Aims: To explore the feasibility of minimally invasive catheter-based electrophysiology studies in the urinary tract. This is a well-known method used in cardiology to investigate and treat arrhythmias.

Methods: We developed an experimental platform which allows electrophysiological recordings with cardiac catheters and conventional needle electrodes in ex vivo pig ureters.

Detection and quantification of overactive bladder activity in patients: Can we make it better and automatic?

Aims: To explore the use of time-frequency analysis as an analytical tool to automatically detect pattern changes in bladder pressure recordings of patients with overactive bladder (OAB). To provide quantitative data on the bladder's non-voiding activity which could improve the current diagnosis and potentially the treatment of OAB.

Methods: We developed an algorithm, based on time-frequency analysis, to analyze bladder pressure during the filling phase of urodynamic studies.

Red blood cell phase separation in symmetric and asymmetric microchannel networks: effect of capillary dilation and inflow velocity.

The non-uniform partitioning or phase separation of red blood cells (RBCs) at a diverging bifurcation of a microvascular network is responsible for RBC heterogeneity within the network. The mechanisms controlling RBC heterogeneity are not yet fully understood and there is a need to improve the basic understanding of the phase separation phenomenon. In this context, in vitro experiments can fill the gap between existing in vivo and in silico models as they provide better controllability than in vivo experiments without mathematical idealizations or simplifications inherent to in silico models.

Urethane anesthesia in acute lower urinary tract studies in the male rat.

Urethane is a widely used anesthetic in animal lower urinary tract research. Our objective was to investigate the quality of anesthesia and the correlation between bladder (voiding) contractions, micturition pressure, bladder capacity and urethane dosage and body weight. Urethane was given subcutaneously and/or intraperitoneally (1.

A novel single compartment in vitro model for electrophysiological research using the perfluorocarbon FC-770.

Electrophysiological studies of whole organ systems in vitro often require measurement of nerve activity and/or stimulation of the organ via the associated nerves. Currently two-compartment setups are used for such studies. These setups are complicated and require two fluids in two separate compartments and stretching the nerve across one chamber to the other, which may damage the nerves.

Neurophysiological modeling of bladder afferent activity in the rat overactive bladder model.

The overactive bladder (OAB) is a syndrome-based urinary dysfunction characterized by "urgency, with or without urge incontinence, usually with frequency and nocturia". Earlier we developed a mathematical model of bladder nerve activity during voiding in anesthetized rats and found that the nerve activity in the relaxation phase of voiding contractions was all afferent. In the present study, we applied this mathematical model to an acetic acid (AA) rat model of bladder overactivity to study the sensitivity of afferent fibers in intact nerves to bladder pressure and volume changes.

Wave intensity analysis in air-filled flexible vessels.

Wave intensity analysis (WIA) is an analytical technique generally used to investigate the propagation of waves in the cardiovascular system. Despite its increasing usage in the cardiovascular system, to our knowledge WIA has never been applied to the respiratory system. Given the analogies between arteries and airways (i.

Frequency analysis of urinary bladder pre-voiding activity in normal and overactive rat detrusor.

Aims: To test the hypothesis that voiding in anesthetized rats is preceded by recurrent changes in the pattern of bladder pressure. To explore the use of frequency analysis as an analytical tool for automatically detecting these changes and to provide quantitative data on bladder pre-voiding activity.

Methods: We developed an algorithm, based on frequency analysis, to study bladder pressure during the filling phase in anesthetized rats.