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News from the Annual Report 2009

News from the Annual Report 2009

Fundamentals of Metrology

Biosensors for MRT in Immunology

In medicine, Magnetic Resonance Tomography (MRT) is an established procedure for non-invasive diagnostics. Due to the intrinsically low detection sensitivity, the high water content of the soft tissues is routinely used ...

Risk assessment of metrological software based on measurement software indices

Within the scope of the ad hoc group "Measurement Software" which was set up by the JCGM/BIPM, PTB and NPL worked together to develop a risk-based approach for the development ...[more]

Simulation of the propagation of impinging and free jets in the field of explosion protection

The knowledge of the propagation and mixing of fluid jets consisting of different components is of fundamental importance in the field of explosion protection, especially for the emission control and the prevention of explosive gas mixtures. Based on the Navier-Stokes equations and depending ...[more]

Influence of model errors on measurement uncertainties in EUV scatterometry

PTB's scatterometry facilities enable the indirect measurement of critical structure quantities of lithographic masks with an accuracy in the nanometre range. To quantify the influence of the variation ...[more]

Evaluation of a recent guide to the determination of the measurement uncertainty

The "Guide to the Expression of uncertainty in measurement (GUM)“ regulates the determination of measurement uncertainties in metrology. In 2008, a supplement to this guide was released (GUM-S1) which describes a numerical Monte Carlo procedure for the calculation of measurement uncertainties. The Guide does not state ...[more]

Analysis of dynamic measurements

The recent development of methods for the determination of measurement uncertainties for the analysis of dynamic measurements has been successfully continued. In 2009, an existing method for linear, time-invariant, dynamic systems ...[more]

Numerical calculation of measurement uncertainties

A Monte Carlo procedure for the numerical calculation of measurement uncertainties has been introduced in a recently published supplement to the Guide to the Expression of Uncertainty in Measurement. In order to keep the numerical effort ...[more]

Measurement of neuronal currents using low-field MR

In the frame of the "Bernstein Focus: Neurotechnology", which is funded by BMBF, the influence of neuronal currents on the magnetic resonance signal in the low-field regime is investigated. For this purpose, the linewidth of the magnetic resonance signal ...[more]

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Metrology for Society

Gene transfer with the aid of magnetic nanoparticles

Magnetic nanoparticles are applied today routinely as a contrast agent for magnetic resonance imaging. In addition to medical diagnostics ...[more]

New ways to characterize breast tumors

In X-ray mammography benign breast tumors are often classified as highly suspicious lesions. Therefore, new or additional imaging techniques are required which offer an improved differentiation ...[more]

Magnetic resonance imaging at ultrahigh fields: problems and potential solutions

In January 2009 the new 7-tesla whole-body MRI scanner of the Berlin ultrahigh field facility at the Max-Delbrück-Centrum (MDC) für Molekulare Medizin in Berlin-Buch was handed over to the users. The facility, a joint venture of MDC, Charité – Universitätsmedizin Berlin, Leibniz-Institut für Molekulare Pharmakologie (FMP) and PTB, is dedicated ...

Data analysis for MEG

Within the scope of a project funded by the DFG and carried out in cooperation with the TU Berlin (Prof. Orglmeister), a new method for the spatial separation of dependent source signals in MEG was developed in 2009. The method ...[more]

Homogenisation in non linear, partial differential equations

The modelling of non linear evolution equations in spatially heterogenous systems is relevant for numerous biological systems, such as, e.g., the excitation spreading in the myocard. Within the scope of a project ...[more]

Qualitative modelling and analysis of cardiac arrhythmias

Computer simulations have enabled the modelling and mathematical analysis of life-threatening cases of cardiac arrhythmia. Especially so-called T wave alternans, a period doubling ...[more]

Technical directive for cash gaming machines notified by the EU

With regard to a decree of the Federal Ministry of Economics, it had become necessary to radically amend the technical directive for cash gaming machines. The revision, as well as the merging ...[more]

Procedure for the testing of measuring instruments with standard operating systems

Measuring instruments are equipped increasingly with computers running Linux or Windows as an operating system. In order to meet ...[more]

Verification procedure for measurement and POS data

Within the scope of the project INSIKA which is fostered by the BMWi, the development of a procedure has been completed by means of which measurement and POS (point-of-sale) data can be reliably checked by auditing entities. The procedure ...[more]

Another contribution to high software security in legal metrology

A modern method to ensure the integrity and the authenticity of software which is based on the use of electronic signatures is available ...[more]

Comparative analysis of voting machine concepts for the preparation of a new Federal Ordinance on Voting Machines

In preparation of the implementation of the decision of the Federal Constitutional Court on voting machines, a comparative examination of known concepts of voting machines has been carried out. The results reveal ...[more]

Joint research project on micro-fabricated flow cytometers successfully completed

The joint research project on the development of micro-fabricated flow cytometers, co-financed by the Investitionsbank Berlin (IBB) and the European Regional Development Fund (EFRE), has been successfully completed. The results obtained in cooperation ...[more]

Improvement of the specificity for the identification of red and white blood cells in cerebrospinal fluid (CSF) by immunological staining

For several years, PTB has participated in interlaboratory comparisons for cell counting in liquor. The aim of these experiments is to apply the measurement methods which are used for the reference value determination of erythrocyte and leukocyte concentrations within the scope of the complete blood count to cell counting in liquor. The concentrations of the leukocytes and erythrocytes ...[more]

New molecular diagnostic and therapeutic procedures in medicine

Within the framework of a cooperation with the Max Delbrück Center for Molecular Medicine (MDC) and the new Center for Experimental and Clinical Research (ECRC) in Berlin, PTB has continued to conduct research which is ...[more]

First steps towards quantitative fluorescence imaging

The use of fluorescent contrast agents for medical imaging is a promising approach which has been explored in different areas – such as the detection of rheumatic diseases, optical mammography or stroke monitoring – for several years at PTB. One important goal is the quantitative determination ...[more]

Clinical trial of a fluorescence imaging method for the detection of breast cancer successfully completed

To evaluate a fluorescence imaging method for the detection of breast cancer, which has recently been developed by PTB, a clinical trial was performed at the Charité Hospital Berlin. The method exploits the permeability of the blood vessels ...[more]

Quantitative verification of the optical perfusion measurement on stroke patients using perfusion-weighted magnetic resonance imaging

Time-resolved near-infrared imaging enables the observation of the passage of a contrast agent bolus directly on the cortex of stroke patients. As shown by a study which is currently being carried out in cooperation with ...[more]

Pilot investigations into the neurovascular coupling mechanisms in stroke patients using a combination of DC magnetoencephalography and time-resolved near-infrared spectroscopy

The combination of DC magnetoencephalography (DC MEG) and time-resolved near-infrared spectroscopy (NIRS) allows the simultaneous recording of neuronal and vascular responses during motor stimulation for the study of neurovascular coupling. Extending the collaboration with Charité University Medicine Berlin ...[more]

Clinical research group "Magnetic iron oxide nanoparticles for cellular and molecular MR imaging (KFO 213)" at the Charité University Hospital in Berlin has started its work

This interdisciplinary clinical research group, which is funded by the DFG, hosts working groups for radiology, cardiovascular medicine and neurosciences from the Charité Hospital and physicists from PTB. Their goal is, using a particular variant of contrast agents ...[more]

SQUID measurements for the transfer of genes

Therapeutically effective genetic material can be transduced into target cells with the aid of viruses. A study of the University of Bonn has investigated how the efficiency of this gene transfer can be increased ...[more]

Magnetic resonance spectroscopic quantification of a neuronal marker in the brain – Implications for the genetics of psychiatric diseases

Proton magnetic resonance spectroscopy enables the non-invasive determination of metabolite concentrations in the human brain. Within the scope of a cooperation with scientists of the Charité Hospital in Berlin ...[more]

UWB radar for high-resolution detection of smallest head movements

Within the scope of the research project ultraMEDIS, Working Group 8.11 has managed to monitor tiniest, unintended head movements – caused, for example, by breathing or heart beat – by means of ultra-wide band (UWB) radar. The research project ultraMEDIS ...[more]

7T MR imaging in the head with spatially selective excitation

Spatially selective excitation is one of the most fascinating novel developments in magnetic resonance imaging (MRI). This technique offers a great potential, especially to avoid certain imaging artifacts in ultra-high-field MRI. The technical equipment ...[more]

Heart imaging with the 7-tesla MRT

Only six months after its commissioning, Berlin's new 7-tesla magnetic resonance imaging scanner (7T MRI) has provided its first heart images. The difficulties in connection with heart beat, breathing and large blood flows make heart imaging ...[more]

PTB's first MR tomograph replaced

An era is drawing to a close in the field of medical physics at PTB: after 14 years of diligent operation, PTB's first magnetic resonance imaging (MRI) scanner, a whole-body system of the type "Bruker Medspec 30/100" has been decommissioned. It is with this machine ...[more]

Berlin ultra-high-field facility commissioned

After five years of preparation, the time had finally come on 21 January 2009: in a ceremonial act, Federal Minister of Education Prof. Annette Schavan symbolically cut the ribbon and thus inaugurated the Berlin Ultrahigh-Field Facility. Located on the campus of the Max Delbrück Center (MDC) ...[more]

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Metrology for Economy

Mathematical methods for non-destructive measurements of nano-structures

The breathtaking development of nanotechnology requires the design and control of components with smaller and smaller details. In particular, the fabrication of up-to-date computer chips and storage devices by lithographic manufacturing processes ...[more]

Load Profile Meter

New approaches for meter systems do not anymore only use information and communication technologies as an accepted addition of meters, but its functionality bases on the systematic exploitation of the communication infrastructure. This development already ranges to meters used ... [more]

New type of magnetometer tested in the shielding room of PTB Berlin

In the past few years, the development of highly sensitive atomic magnetometers has made considerable progress. At the National Institute of Standards and Technology/USA (NIST), optical micromagnetometers ... [more]

Quantitative imaging of magnetic nanoparticles

The successful use of magnetic nanoparticles as carriers of drugs in medicine requires the exact knowledge of their quantitative distribution in the tissue. The characterisation of the particle distributions ...[more]

Model-aided dynamic calibration of force transducers

Dynamic force signals are measured by highly dynamic force transducers. The dynamics of the measurements, however, is always determined by the measuring chain consisting of the force introduction and the force transducer. The force introduction depends ...[more]

Consideration of correlations for the time range calibration of ultra-fast sampling oscilloscopes

The determination of characteristics of ultra-fast sampling oscilloscopes by means of calibration measurements requires the use of mathematical methods such as deconvolution algorithms and Monte Carlo simulations. A method ...[more]

Validation of a new optical flatness reference system by means of virtual experiments

A new optical reference system for the measurement of flatness established in Working Group 4.21 "Form and Wavefront Metrology" has been validated by means of virtual experiments. With this flatness reference system ...[more]

Resolution and limits of Fluorescence Lifetime Correlation Spectroscopy (FLCS)

Fluorescence correlation spectroscopy (FCS) is a method to examine local fluctuations of molecules and their dynamic properties such as, e.g., diffusion. Fluctuations in the fluorescence intensity of a dye molecule are usually assessed to this end. Using time-correlated single photon counting ...[more]

MNPQ Project "AHD Method for the Determination of the Haemoglobin Concentration"

Within the scope of an MNPQ project, work on the validation of the AHD (alkaline haematin detergent) method as an improved routine procedure and a new reference procedure for the determination of the haemoglobin concentration in blood was initiated and started in cooperation with Medisynthana Diagnostics GmbH & Co. KG. The aim of the project ...[more]

AP39-TSP – a molecular probe for the imaging of rheumatoid arthritis in subtalar joints in vivo

Rheumatoid arthritis (RA) is a systemic inflammatory disease which affects approx. 1 % of the population. For supplying the fast growing inflamed tissue with nutrients, new vessels are created (angiogenesis). An established angiogenesis marker is the oncofetal isoform ...[more]

Clinical study on fluorescence-based detection of rheumatic diseases successfully completed

A clinical study on fluorescence imaging towards early detection of rheumatoid arthritis was carried out in cooperation with mivenion GmbH and the Helios Clinics and has been completed succesfully. Within this study ...[more]

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International Affairs

Application of atomic micro magnetometers for the recording of MCG and of magnetic relaxation curves

The National Institute of Standards and Technology/USA (NIST) has recently developed highly sensitive atomic micro magnetometers based on the technology of miniaturised atomic clocks. Such a magnetometer ...[more]

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