[Research Ethics Committees--who is to represent the community?]. / Forskningsetikkommittéerna--vem ska representera allmänheten?

The Swedish Government has proposed a law for the ethical regulation of research on human beings. The proposal entails changes in the composition of Research Ethics Committees with regard to community representation. A study indicates that healthcare staff with no ties to research would appear to merit particular public confidence, as would representatives of the legal profession, moral philosophers and priests.

[Treatment of cardiac arrest in potential organ donors creates ethical conflicts]. / Hjertestopbehandling af potentielle organdonorer skaber etiske konflikter.

This article describes the results of an interview study on the ethical issues related to treating cardiac arrest in potential organ donors in Denmark. The medical background and the Danish guidelines relevant to the issue are described. The results from the interview study are then summarized and analyzed from an ethical perspective in order to clarify the ethical issues and value conflicts experienced by health personnel in this situation. It is recommended that the ethical components in the decision-making process and the dilemmatic nature of the situation are made transparent.

CFD and PTV steady flow investigation in an anatomically accurate abdominal aortic aneurysm.

There is considerable interest in computational and experimental flow investigations within abdominal aortic aneurysms (AAAs). This task stipulates advanced grid generation techniques and cross-validation because of the anatomical complexity. The purpose of this study is to examine the feasibility of velocity measurements by particle tracking velocimetry (PTV) in realistic AAA models. Computed tomography and rapid prototyping were combined to digitize and construct a silicone replica of a patient-specific AAA. Three-dimensional velocity measurements were acquired using PTV under steady averaged resting boundary conditions. Computational fluid dynamics (CFD) simulations were subsequently carried out with identical boundary conditions. The computational grid was created by splitting the luminal volume into manifold and nonmanifold subsections. They were filled with tetrahedral and hexahedral elements, respectively. Grid independency was tested on three successively refined meshes. Velocity differences of about 1% in all three directions existed mainly within the AAA sack. Pressure revealed similar variations, with the sparser mesh predicting larger values. PTV velocity measurements were taken along the abdominal aorta and showed good agreement with the numerical data. The results within the aneurysm neck and sack showed average velocity variations of about 5% of the mean inlet velocity. The corresponding average differences increased for all velocity components downstream the iliac bifurcation to as much as 15%. The two domains differed slightly due to flow-induced forces acting on the silicone model. Velocity quantification through narrow branches was problematic due to decreased signal to noise ratio at the larger local velocities. Computational wall pressure and shear fields are also presented. The agreement between CFD simulations and the PTV experimental data was confirmed by three-dimensional velocity comparisons at several locations within the investigated AAA anatomy indicating the feasibility of this approach.