Event-Centered Data Segmentation in Accelerometer-Based Fall Detection Algorithms.

Automatic fall detection systems ensure that elderly people get prompt assistance after experiencing a fall. Fall detection systems based on accelerometer measurements are widely used because of their portability and low cost. However, the ability of these systems to differentiate falls from Activities of Daily Living (ADL) is still not acceptable for everyday usage at a large scale. More work is still needed to raise the performance of these systems. In our research, we explored an essential but often neglected part of accelerometer-based fall detection systems-data segmentation. The aim of our work was to explore how different configurations of windows for data segmentation affect detection accuracy of a fall detection system and to find the best-performing configuration. For this purpose, we designed a testing environment for fall detection based on a Support Vector Machine (SVM) classifier and evaluated the influence of the number and duration of segmentation windows on the overall detection accuracy. Thereby, an event-centered approach for data segmentation was used, where windows are set relative to a potential fall event detected in the input data. Fall and ADL data records from three publicly available datasets were utilized for the test. We found that a configuration of three sequential windows (pre-impact, impact, and post-impact) provided the highest detection accuracy on all three datasets. The best results were obtained when either a 0.5 s or a 1 s long impact window was used, combined with pre- and post-impact windows of 3.5 s or 3.75 s.

A TECHNOLOGY OVERVIEW OF ACTIVE IONIZING RADIATION DOSEMETERS FOR PHOTON FIELDS.

Radiation protection and radiation dosimetry strongly rely on measurements performed by dosimetry instrumentation. Two categories of dosimetry instrumentation prevail: personal dosemeters and survey meters. Passive dosemeters were for many years the base of personal and area dosimetry (environmental, including workplace). Survey meters have been long-established between area meters due to their dose rate measurement capability, but just over a decade ago, debates over possibility that electronic personal dosemeters (EPDs) could replace passive personal dosemeters as legal monitoring devices have started. These debates have now branched into the use of EPDs, but also survey meters in various exposure scenarios, where some concerns have been reported. These concerns were mostly related to the response in pulsed X-ray fields and poor energy response. This article summarizes recent literature related to electronic dosemeters for strongly penetrating photon radiation and covers technologies used in contemporary EPDs and survey meters, their performance and future perspectives.

Utilizing Impedance for Quality Assessment of European Squid (Loligo Vulgaris) during Chilled Storage.

This study evaluates the quality of chilled squid Loligo vulgaris by non-destructive measurements of bioelectrical impedance from the first post-mortem day under controlled conditions. Squid samples were stored at 4.5 °C and 55% of relative humidity for 11 days. Impedance magnitude (|Z|) and phase (φ) at 200 frequencies (100Hz to 100MHz) were measured using an Agilent 4294A Precision Impedance Analyzer with needle-type multi-electrode array on days 1, 2, 3, 4, 5, 8, 9, 10, and 11 of storage. The changes in color, sensory properties, total volatile nitrogen, pH, and water holding capacity were also determined. The obtained results indicated that the samples could be classified into five to six distinctive groups by measuring the electrical parameters at frequencies close to 5MHz. In general, φ is less dependent on temperature and measurement setup than |Z|, while records at 5MHz correlate well with the days of storage (R2 = 0.968). The data imply that it is only possible to estimate the length of storage for the samples with measurements of phase angle, which can be useful for the development of new analytical instruments. Biosensors have a practical industrial application, as it is demonstrated that bioelectrical impedance data correlates well with the days of chilled storage.

Modeling of electric field distribution in tissues during electroporation.

BACKGROUND: Electroporation based therapies and treatments (e.g. electrochemotherapy, gene electrotransfer for gene therapy and DNA vaccination, tissue ablation with irreversible electroporation and transdermal drug delivery) require a precise prediction of the therapy or treatment outcome by a personalized treatment planning procedure. Numerical modeling of local electric field distribution within electroporated tissues has become an important tool in treatment planning procedure in both clinical and experimental settings. Recent studies have reported that the uncertainties in electrical properties (i.e. electric conductivity of the treated tissues and the rate of increase in electric conductivity due to electroporation) predefined in numerical models have large effect on electroporation based therapy and treatment effectiveness. The aim of our study was to investigate whether the increase in electric conductivity of tissues needs to be taken into account when modeling tissue response to the electroporation pulses and how it affects the local electric distribution within electroporated tissues. METHODS: We built 3D numerical models for single tissue (one type of tissue, e.g. liver) and composite tissue (several types of tissues, e.g. subcutaneous tumor). Our computer simulations were performed by using three different modeling approaches that are based on finite element method: inverse analysis, nonlinear parametric and sequential analysis. We compared linear (i.e. tissue conductivity is constant) model and non-linear (i.e. tissue conductivity is electric field dependent) model. By calculating goodness of fit measure we compared the results of our numerical simulations to the results of in vivo measurements. RESULTS: The results of our study show that the nonlinear models (i.e. tissue conductivity is electric field dependent: σ(E)) fit experimental data better than linear models (i.e. tissue conductivity is constant). This was found for both single tissue and composite tissue. Our results of electric field distribution modeling in linear model of composite tissue (i.e. in the subcutaneous tumor model that do not take into account the relationship σ(E)) showed that a very high electric field (above irreversible threshold value) was concentrated only in the stratum corneum while the target tumor tissue was not successfully treated. Furthermore, the calculated volume of the target tumor tissue exposed to the electric field above reversible threshold in the subcutaneous model was zero assuming constant conductivities of each tissue.Our results also show that the inverse analysis allows for identification of both baseline tissue conductivity (i.e. conductivity of non-electroporated tissue) and tissue conductivity vs. electric field (σ(E)) of electroporated tissue. CONCLUSION: Our results of modeling of electric field distribution in tissues during electroporation show that the changes in electrical conductivity due to electroporation need to be taken into account when an electroporation based treatment is planned or investigated. We concluded that the model of electric field distribution that takes into account the increase in electric conductivity due to electroporation yields more precise prediction of successfully electroporated target tissue volume. The findings of our study can significantly contribute to the current development of individualized patient-specific electroporation based treatment planning.

Promoting harmonization of BME education in Europe: the CRH-BME Tempus project.

Biomedical Engineers should be prepared to adapt to existing or forecasted needs. There is a strong pressure on education, training and life long learning programs to continuously adapt their objectives in order to face new requirements and challenges. The main objective of the TEMPUS IV, CRH-BME project is to update existing curricula in the field of Biomedical Engineering (BME) in order to meet recent and future developments in the area, address new emerging inter-disciplinary domains that appear as a result of the R&D progress and respond to the BME job market demands. The first step is to extensively review the curricula in the BME education field. In this paper, a proposal for a generic curriculum in the BME education is presented, in order to meet recent and future developments and respond to the demands of the BME job market. Adoption of the core program structure will facilitate harmonization of studies as well as student and staff exchange across Europe, thus promoting the European Higher Education Area.

Challenges of the biomedical engineering education in Europe.

Higher education in Europe has passed through a very dynamic period of changes during the last ten years. Since the signing of the Bologna Declaration in 1999 by the Ministers of Education from the EU states, European higher education system has aimed toward establishing harmonized programs enabling students and teachers to extensively exchange knowledge, ideas and skills. Education in the field of Biomedical Engineering has experienced changes also because of the research and development in the field which was more intensive than in other fields. Besides research in new power sources, it is the most intensive and productive research field. Much of the development in BME education in Europe is influenced by the European research policy expressed through the 7th Framework Programme where health is the major theme. In order to foster and support the changes in the European Higher Education Area (EHEA) according to the needs of research sector and the labor market, the Tempus scheme of projects was established. Tempus scheme aims to support the modernization of higher education and create an area of co-operation in the countries surrounding the EU. Our Tempus project, CRH-BME "Curricula Reformation and Harmonization in the field of Biomedical Engineering" aims to create guidelines for updating existing curricula in the field of BME in Europe in order to meet recent and future developments in the area, address new emerging interdisciplinary domains that appear as the result of the R&D progress and respond to the BME job market demands. In this paper, some policy and economic factors affecting BME education in Europe are discussed and the results of a BME education survey we prepared within the Tempus CHR-BME project are presented. The number of BME programmes in Europe has in the last decade significantly increased and there are more BME specializations as the result of growing complexity of the research and production in the field.