The EASI project-improving the effectiveness and quality ofimage-guided surgery

In recent years, advances in computer technology and a significant increase in the accuracy of medical imaging have made it possible to develop systems that can assist the clinician in diagnosis, planning, and treatment. This paper deals with an area that is generally referred to as computer-assisted surgery, image-directed surgery, or image-guided surgery. We report the research, development, and clinical validation performed since January 1996 in the European Applications in Surgical Interventions (EASI) project, which is funded by the European Commission in their “4th Framework Telematics Applications for Health” program. The goal of this project is the improvement of the effectiveness and quality of image-guided neurosurgery of the brain and image-guided vascular surgery of abdominal aortic aneurysms, while at the same time reducing patient risks and overall cost. We have developed advanced prototype systems for preoperative surgical planning and intraoperative surgical navigation, and we have extensively clinically validated these systems. The prototype systems and the clinical validation results are described in this paper     

Multimodality image registration by maximization of mutualinformation

A new approach to the problem of multimodality medical image registration is proposed, using a basic concept from information theory, mutual information (MI), or relative entropy, as a new matching criterion. The method presented in this paper applies MI to measure the statistical dependence or information redundancy between the image intensities of corresponding voxels in both images, which is assumed to be maximal if the images are geometrically aligned. Maximization of MI is a very general and powerful criterion, because no assumptions are made regarding the nature of this dependence and no limiting constraints are imposed on the image content of the modalities involved. The accuracy of the MI criterion is validated for rigid body registration of computed tomography (CT), magnetic resonance (MR), and photon emission tomography (PET) images by comparison with the stereotactic registration solution, while robustness is evaluated with respect to implementation issues, such as interpolation and optimization, and image content, including partial overlap and image degradation. Our results demonstrate that subvoxel accuracy with respect to the stereotactic reference solution can be achieved completely automatically and without any prior segmentation, feature extraction, or other preprocessing steps which makes this method very well suited for clinical applications     

Effect of wind stress forcing on ocean dynamics at air-sea interface

We evidence and study the differences in turbulence statistics in ocean dynamics carried by wind forcing at the air-sea interface. Surface currents at the air-sea interaction are of crucial importance because they transport heat from low to high latitudes. At first order, oceanic currents are generated by the balance of the Coriolis and pressure gradient forces (geostrophic current) and the balance of the Coriolis and the frictional forces dominated by wind stress (Ekman current) in the surface ocean layers. The study was conducted by computing statistical moments on the shapes of spectra computed within the framework of microcanonical multi-fractal formalism. Remotely sensed daily datasets derived from one year of altimetry and wind data were used in this study, allowing for the computation of two kinds of vector fields: geostrophy with and geostrophy without wind stress forcing. We explore the statistical properties of singularity spectra computed from velocity norms and vorticity data, notably in relation with kurtosis information to underline the differences in the turbulent regimes associated with both kinds of velocity fields.     

Spontaneous imbibition in a microchannel: analytical solution and assessment of volume of fluid formulations

The simulation of multi-phase flow at low capillary numbers (Ca) remains a challenge. Approximate computations of the capillary forces tend to induce parasitic currents (PC) around the interface. These PC induce additional viscous dissipation and shear forces that potentially lead to wrong calculations of the general flow dynamics. Here, we focus on the case of spontaneous imbibition in a microchannel of Hele-Shaw cell symmetry with capillarity being the only driving force. We extend the Lucas–Washburn equation to account for arbitrary viscosity ratios and assess four volume-of-fluid (VOF) formulations against the analytical solution. More specifically, we evaluate the continuum surface force (CSF) formulation, the sharp surface force (SSF) formulation, the filtered surface force (FSF) formulation and the piecewise linear interface calculation (PLIC) formulation extended by a higher order discretisation of the interface curvature through a height function with respect to accuracy, performance and heuristic parameters. We quantify PC for each formulation and investigate their impact on flow with \(\mathrm{Ca} < 10^{-2}\). The magnitude of PC are largest for CSF and are reduced two fold by SSF. FSF reduces PC considerably more but shows periodic short bursts in the velocity field. PLIC shows no PC for the studied \(\mathrm{Ca}\) and viscosity ratios. However, it fails when a denser fluid displaces a lighter fluid. Despite PC, all formulations are accurate within 10%. PLIC is suited to serve as a reference but relies on a structured mesh and is computationally expensive. FSF requires more heuristic parameters. Together with periodic bursts, this prevents a conclusive statement on the best choice between SSF and FSF.     

A school-based intervention improved dietary intake outcomes and reduced waist circumference in adolescents: a cluster randomized controlled trial

Background

In Ecuador, adolescents’ food intake does not comply with guidelines for a healthy diet. Together with abdominal obesity adolescent’s inadequate diets are risk factors for non-communicable diseases. We report the effectiveness of a school-based intervention on the dietary intake and waist circumference among Ecuadorian adolescents.

Methods

A pair-matched cluster randomized controlled trial including 1430 adolescents (12–14 years old) was conducted. The program aimed at improving the nutritional value of dietary intake, physical activity (primary outcomes), body mass index, waist circumference and blood pressure (secondary outcomes). This paper reports: (i) the effect on fruit and vegetable intake, added sugar intake, unhealthy snacking (consumption of unhealthy food items that are not in line with the dietary guidelines eaten during snack time; i.e. table sugar, sweets, salty snacks, fast food, soft drinks and packaged food), breakfast intake and waist circumference; and, (ii) dose and reach of the intervention. Dietary outcomes were estimated by means of two 24-h recall at baseline, after the first 17-months (stage one) and after the last 11-months (stage two) of implementation. Dose and reach were evaluated using field notes and attendance forms. Educational toolkits and healthy eating workshops with parents and food kiosks staff in the schools were implemented in two different stages. The overall effect was assessed using linear mixed models and regression spline mixed effect models were applied to evaluate the effect after each stage.

Results

Data from 1046 adolescents in 20 schools were analyzed. Participants from the intervention group consumed lower quantities of unhealthy snacks (?23.32 g; 95% CI: ?45.25,-1.37) and less added sugar (?5.66 g; 95% CI: ?9.63,-1.65) at the end of the trial. Daily fruit and vegetable intake decreased in both the intervention and control groups compared to baseline, albeit this decrease was 23.88 g (95% CI: 7.36, 40.40) lower in the intervention group. Waist circumference (?0.84 cm; 95% CI: ?1.68, 0.28) was lower in the intervention group at the end of the program; the effect was mainly observed at stage one. Dose and reach were also higher at stage one.

Conclusions

The trial had positive effects on risk factors for non-communicable diseases, i.e. decreased consumption of unhealthy snacks. The program strategies must be implemented at the national level through collaboration between the academia and policy makers to assure impact at larger scale.

Trial registration

ClinicalTrial.gov-NCT01004367.

     

Influence of the synthesis method of Al-hydroxy intercalated clays on their fulvic acid sorption capacity

The purpose of this study was to investigate the potential use of both Al-hydroxy intercalated clays and ‘pillared clays’ (calcinated Al-hydroxy intercalated clays) for the removal of fulvic acids (FA) from water. Different preparation procedures of the Al-hydroxy intercalated clays were tested and the products were characterised (XRD and N₂ sorption) and tested for their FA sorption capacity. It was observed that the drying method (oven or freeze-drying) and the calcination step were the most important parameters influencing the FA sorption capacity of the Al-hydroxy intercalated clays. The noncalcined freeze-dried Al-hydroxy intercalated clays showed the largest sorption capacity for FA. Comparison with freeze-dried Wyoming bentonite and granular activated carbon showed that this freeze-dried Al-hydroxy intercalated clays are potential good sorbents for the removal of fulvic acids from water.     

Ein Mikrowaschtest zur Bestimmung der Enzymwirkung

A Micro Wash Test for the Determination of Enzyme Performance A micro wasch test as well as two test fabrics stained with denatured proteins were developed. Test fabric A (blood-egg) responds only to proteases. When the latter are absent, no change in reflectance occurs either by agitation during washing, by detergents or by electrolytes at any pH below 11.5. Test fabric B (chocolate – milk) also responds only to proteases. In blank wash tests without enzyme no stain remova occurs. On the contrary, in blank tests this test fabric shows increased darkening with increasing pH. With these test fabrics the micro wash test has been used to evaluate the practical performance of very small quantities of enzymes isolated by gel chromatography or electrophoresis.     

Influence of agitator design and catalyst concentration on partial hydrogenation of sunflower oil

In this study, lab‐scale hydrogenation of sunflower oil was conducted at 190 °C and 2 bar using two different catalyst types at varying concentrations and two different agitator designs (surface gassing and hollow shaft) at varying power inputs. At identical power input and reaction conditions, the reaction rate with the hollow‐shaft agitator was 1.68 times higher than with surface gassing agitation. The catalyst concentration had to exceed a certain feedstock‐dependent threshold value of 25 ppm Ni in order to start the reaction. At low catalyst concentration, the reaction rate increased proportionally with increasing catalyst concentration. When hydrogen consumption became higher than the available mass transfer provided by the agitation system, the reaction time became less dependent on the catalyst concentration. For the hollow‐shaft agitator, this situation was observed at a reaction rate of 3.7 ΔIV/min, where trans formation was at its maximum with more than 40% trans fatty acids in partially hydrogenated sunflower oil with IV 65. The region in which hydrogen mass transfer did not limit the reaction rate could be extended by more efficient agitation design or increased agitation power. In this way, productivity can be increased and trans formation can be controlled in a better way when compared to hydrogenation with a less efficient agitator.     

Formalin-fixed paraffin-embedded tissue: The holy grail of clinical proteomics?

Tissue is the most relevant biological material to gather insight in disease mechanisms by means of omics technologies. However, fresh frozen tissue, which is generally regarded as the best imaginable source for such studies, is often not available. In case it is available, the different ways of storage (e.g. −20°C, −80°C, liquid nitrogen, etc.) hamper the conduction of reproducible multicenter studies because of different protein degradation rates. Formalin-fixed paraffin-embedded (FFPE) tissue on the contrary is considered as a valuable alternative for fresh frozen tissue, because only a few standard operation procedures are applied worldwide for the preparation of these tissues and because they are all stored in the same way. However, a study on the impact of the different preparation protocols for FFPE tissue was still lacking. Therefore, Bronsert et al. in this issue [Bronsert, P., Weißer, J., Biniossek, M. L., Kuehs, M. et al., Proteomics Clin. Appl. 2014, 8 786–804] conducted such a study that provides proof that there is no significant effect between these sample preparations procedures, and thereby they further open the gate for FFPE tissues to enter the field of clinical proteomics.     

The “Conducting Master”: An Interactive,Real-Time Gesture Monitoring System Based on Spatiotemporal Motion Templates

Research in the field of embodied music cognition has shown the importance of coupled processes of body activity (action) and multimodal representations of these actions (perception) in how music is processed. Technologies in the field of human–computer interaction (HCI) provide excellent means to intervene into, and extend, these coupled action-perception processes. In this article this model is applied to a concrete HCI application, called the “Conducting Master.” The application facilitates multiple users to interact in real time with the system in order to explore and learn how musical meter can be articulated into body movements (i.e., meter-mimicking gestures). Techniques are provided to model and automatically recognize these gestures in order to provide multimodal feedback streams back to the users. These techniques are based on template-based methods that allow approaching meter-mimicking gestures explicitly from a spatiotemporal account. To conclude, some concrete setups are presented in which the functionality of the Conducting Master was evaluated.