Testing spirometers: are the standard curves of the american thoracic society sufficient?

Background: The performance of spirometers is often measured only under ideal conditions, with a mechanical simulator reproducing the expiratory standard American Thoracic Society (ATS) curves generated by a computer. Studies have questioned the value of these results in real-life conditions. The aim of this study was to evaluate the accuracy and precision of 5 office spirometers with a flow-volume simulator using the ATS curves and using flow-volume curves obtained from patients.

Validation of a 1D patient-specific model of the arterial hemodynamics in bypassed lower-limbs: simulations against in vivo measurements.

The validation of a coupled 1D-0D model of the lower-limb arterial hemodynamics is presented. This study focuses on pathological subjects (6 patients, 72.7±11.

Technical assessment of spirometers connected in series.

Background: Office spirometers are now widely used to detect obstructive lung diseases. To test the technical characteristics of these devices, simulation of different forced expiratory maneuvers is performed, using computer generated waveforms. However, the tests with human subjects are also useful to detect technical flaws.

Inlet boundary conditions for blood flow simulations in truncated arterial networks.

In the context of patient-specific cardiovascular applications, hemodynamics models (going from 3D to 0D) are often limited to a part of the arterial tree. This restriction implies the set up of artificial interfaces with the remaining parts of the cardiovascular system. In particular, the inlet boundary condition is crucial: it supplies the impulsion to the system and receives the reflected backward waves created by the distal network.

Thermal and hydrodynamic modelling of active catheters for interventional radiology.

Interventional radiologists desire to improve their operating tools such as catheters. Active catheters in which the tip is moved using shape memory alloy actuators activated using the Joule effect present a promising approach for easier navigation in the small vessels. However, the increase in temperature caused by this Joule effect must be controlled in order to prevent damage to blood cells and tissues.

Accurate modelling of unsteady flows in collapsible tubes.

The context of this paper is the development of a general and efficient numerical haemodynamic tool to help clinicians and researchers in understanding of physiological flow phenomena. We propose an accurate one-dimensional Runge-Kutta discontinuous Galerkin (RK-DG) method coupled with lumped parameter models for the boundary conditions. The suggested model has already been successfully applied to haemodynamics in arteries and is now extended for the flow in collapsible tubes such as veins.

A numerical hemodynamic tool for predictive vascular surgery.

We suggest a new approach to peripheral vascular bypass surgery planning based on solving the one-dimensional (1D) governing equations of blood flow in patient-specific models. The aim of the present paper is twofold. First, we present the coupled 1D-0D model based on a discontinuous Galerkin method in a comprehensive manner, such as it becomes accessible to a wider community than the one of mathematicians and engineers.