Robot-Assisted Image-Guided Interventions

Image guidance is a common methodology of minimally invasive procedures. Depending on the type of intervention, various imaging modalities are available. Common imaging modalities are computed tomography, magnetic resonance tomography, and ultrasound. Robotic systems have been developed to enable and improve the procedures using these imaging techniques. Spatial and technological constraints limit the development of versatile robotic systems. This paper offers a brief overview of the developments of robotic systems for image-guided interventions since 2015 and includes samples of our current research in this field

Robot-Assisted Image-Guided Interventions

Image guidance is a common methodology of minimally invasive procedures. Depending on the type of intervention, various imaging modalities are available. Common imaging modalities are computed tomography, magnetic resonance tomography, and ultrasound. Robotic systems have been developed to enable and improve the procedures using these imaging techniques. Spatial and technological constraints limit the development of versatile robotic systems. This paper offers a brief overview of the developments of robotic systems for image-guided interventions since 2015 and includes samples of our current research in this field

Refractive index sensing with localized plasmonic resonances – Theoretical description and experimental verification

In this thesis the sensing properties of plasmonic resonators for changes in the surrounding refractive index are investigated. A self-consistent and general sensing theory is developed. This theory connects the electrodynamic properties of plasmonic resonators like resonance wavelength and electric field distribution to the sensitivity for refractive index changes. A figure of merit (FOM) is derived which includes the effects of noise and in its general form directly states if a certain change in refractive index will be measurable or not. For the FOM in the quasi-static limit absolute bounds and scalings are derived. These bounds are based on the localization of electromagnetic energy for which analytic expressions were known before. The important result of the quasi-static considerations is that the sensitivity is determined completely by the choice of material and resonance wavelength for refractive index changes that cover the whole sensing volume while for smaller analytes the energy confinement to the analyte volume is important. To confirm the developed theory numerical calculations and an experiment with crescent shaped plasmonic resonators is carried out and good agreement is found. In this experimental verification, local refractive index changes were introduced close to the crescent shaped particles and their resonance wavelength change was measured. As a model analyte polystyrene colloids were used and manipulated with an atomic force microscope. This approach leads to a very defined and controllable model system which allowed the theoretical predictions to be verified without parasitic effects. The proposed theoretical model predicts the measured wavelength changes with high accuracy and allows to extrapolate the result to the response of the resonator to the binding of a single molecule to its surface. From the theory together with the experiment it follows, that single molecule sensitivity will be possible by increasing the signal to noise ratio of the measurement

Second order sufficient optimality conditions for some state-constrained control problems of semilinear elliptic equations

This paper deals with a class ofoptimal control problems governed by elliptic equations with nonlinear boundary condition. The case ofb oundary control is studied. Pointwise constraints on the control and certain equality and set-constraints on the state are considered. Second order sufficient conditions for local optimality of controls are established

Different aspects in the quantification of the Sky View Factor in complex environments.

This paper examines potential applications of the sky view factor (SVF) regarding two- or threedimensional sites. First, the concepts of the radiation budget, Lambert's cosine law and hemispherical description of radiating of en vironments are introduced and connected to the sky view factor. Based on a comparison between different models and methods which calculate the SVF, the paper then focuses on two different kinds of SVFcalculation depending on the type of analyzed site. It is assumed that in case the point of interest represents a flat, two-dimensional area, it makes sense to include the cosine law whereas in case the point of interest represents a solid three-dimensional object the application of Lambert's law could have to be applied in another way. It is shown that the inclusion or exclusion of the cosine law results in different SVF values. It is concluded that depending on the type of surveyed area, the application of a 2D- or 3D-sky view factor should be considered in order to get a better approximation of the radiation fluxes

Analysis of the bioclimatic conditions within different surface structures in a medium-sized city : Szeged, Hungary

A városklíma kutatásokon belül a humán bioklimatológia napjaink egyik legdinamikusabban fejlődő részterülete. Az utóbbi években számos indexet fejlesztettek ki annak számszerűsítésére, hogy mekkora az emberi szervezetet érő hőterhelés különböző környezetben, illetve milyenek az emberi test és a környezete közötti energiaáramlási viszonyok. Jelen vizsgálatunkban egy esettanulmányt mutatunk be Szeged (160 000 lakosú város Magyarország délkeleti határszélén) példáján, melyben egy kis mintaterület bioklimatikus viszonyait elemezzük. Bioklimatológiai szempontból alapvető fontosságú, hogy a vizsgált test direkt sugárzásnak kitett, vagy árnyékban lévő ponton helyezkedik-e el. Mintaterületünk a város magas beépítettségű belvárosi régiójában található, szűk utcakanyonok jellemzik, 20-30 éves (20-30 m magas) útszéli fasorral. A sugárzási viszonyok tehát ezen feltételeknek megfelelően módosulnak. Tanulmányunkban bemutatjuk, hogy hogyan reagálnak a különböző bioklíma indexek-értékek (például a PMV-Predicted Mean Vote és a PET-Physiological Equivalent Temperature) a felszíni struktúra megváltoztatására. Az indexszámításokat RayMan modell segítségével végeztük. Summary - Human biometeorological approaches have an important role in applied urban climatology. Several different thermal indices were developed in the last decades to describe human comfort or heat stress of the human body based on the energy fluxes between the body and environment In this study some results of recent biometeorological investigations in a south-eastern Hungarian city, Szeged (population 160,000) are presented. From point of view of human biometeorology, the key question is whether the examined body is in the shade or is exposed to direct radiation. Our sample area is in a heavily built-up city centre region with narrow streets and several 20-30 year old (20-30 m tall) trees, so radiation fluxes are determined basically by these factors. This paper shows how the bioclimatic indices, Predicted Mean Vote (PMV), Physiological Equivalent Temperature (PET) depend on the situation of radiation at a certain place. It was examined what is the relation between the structure and possible changes of the built-up area and the indices. All the calculations, Tom, PMV and PET were performed with RayMan model

Boundaries for career success? How work–home integration and perceived supervisor expectation affect careers

The necessity to actively manage the work–home boundaries has drastically increased. We postulate that work–home integration may affect individuals' subjective career success via its positive effects on work goal attainment and exhaustion. Furthermore, we study perceived supervisor expectation for employee work–home integration as a boundary condition. Our three-wave online survey with 371 employees showed support for the two hypothesized moderated mediation effects. Work–home integration preference is indirectly related to subjective career success: (1) positively via home-to-work transitions and work goal attainment and (2) negatively via home-to-work transitions and exhaustion. Perceived supervisor expectation constrained work–home integration preference's direct effect on home-to-work transitions and indirect effects on subjective career success. Exploratory analysis revealed that exhaustion negatively affected all career success dimensions, whereas work goal attainment was only related to some. Our results indicate that supervisor expectation can override the effect of employee's work–home integration preference on home-to-work transitions which have a double-edged sword effect on subjective career success. Our study contributes to integrating the careers and work–life interface literature and incorporating contextual factors. Furthermore, with the exploration of differential effects on subjective career success, we advance our understanding of this outcome's nomological network

Histological markers in nasal mucosa of patients with Alzheimer's disease

Neuropathological changes such as dystrophic neurites and the presence of abnormal tau protein in the olfactory system, including primary sensory cells and nerve fibres have previously been demonstrated in nasal mucosa tissue of patients with Alzheimer's disease (AD). These changes were detected in autopsy-derived material from histopathologically confirmed AD cases as well as in biopsy tissue from clinical severely ill AD patients. To investigate the potential usefulness for the early diagnosis of AD, we obtained biopsy tissue from olfactory mucosa from 5 clinically mild to moderate AD patients and stained for the presence of tau or beta-amyloid by immunocytochemistry using a panel of specific antibodies. No positive staining was found in any of the cases. For comparison, post-mortem olfactory tissue from AD patients with severe neuropathological changes (widespread neurofibrillary tangles and amyloid in the brain) was investigated, in these severe cases, tau immunoreactivity was found in fine nerve fibres in the lamina propria and in a few olfactory epithelial cells. These results are consistent with other reports showing that cytoskeletal changes and tau pathology in the olfactory epithelium are not primary (or specific) features of AD and may occur predominantly in late stages of the disease

Early functional results after Hemiarthroplasty for femoral neck fracture: a randomized comparison between a minimal invasive and a conventional approach

BACKGROUND: A minimal invasive approach for elective hip surgery has been implemented in our institution in the past. It is widely hypothesized that implanting artificial hips in a minimal invasive fashion decreases surgical trauma and is helpful in the rehabilitation process in elective hip surgery. Thereby geriatric patients requiring emergency hip surgery also could theoretically benefit from a procedure that involves less tissue trauma. METHODS: Sixty patients who sustained a fractured neck of femur were randomly assigned into two groups. In the minimal invasive arm, the so called “direct anterior approach” (DAA) was chosen, in the conventional arm the Watson-Jones-Approach was used for implantation of a bipolar hemi-arthroplasty. Primary outcome parameter was the mobility as measured by the four-item-Barthel index. Secondary outcome parameters included pain, haemoglobin-levels, complications, duration of surgery, administration of blood transfusion and external length of incision. Radiographs were evaluated. RESULTS: A statistically significant difference (p = 0,009) regarding the mobility as measured with the four-item Barthel index was found at the 5th postoperative day, favouring the DAA. Evaluation of the intensity of pain with a visual analogue scale (VAS) showed a statistically significant difference (p = 0,035) at day 16. No difference was evident in the comparison of radiographic results. CONCLUSIONS: Comparing two different approaches to the hip joint for the implantation of a bipolar hemi-arthroplasty after fractured neck of femur, it can be stated that mobilization status is improved for the DAA compared to the WJA when measured by the four-item Barthel index, there is less pain as measured using the VAS. There is no radiographic evidence that a minimal invasive technique leads to inferior implant position. Level of Evidence: Level II therapeutic study