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O Kosch

Publications and source records attributed to O Kosch.

5 recordsLinked to original sources
PubMed2004

Discrimination of multiple sources using a SQUID vector magnetometer.

For many biomagnetic applications the discrimination between simultaneously active sources is required. To evaluate the performance of a given SQUID system in this respect, the angle between the signal vectors of different sources is used. If the angle reaches large values, discrimination between the multiple sources is possible. We tested this approach with the first module of a new vector magnetometer system consisting of 19 identical modules. Two examples of measurements illustrate the differentiation of multiple sources, i.e. the fetal and the mother's heart signal, and alpha rhythm and heart signal in MEG recordings. This first module of a vector magnetometer system containing 16 SQUIDs is operated at PTB in the new Berlin Magnetically Shielded Room (BMSR 2) The spatial configuration of the 16 integrated SQUID magnetometers of the module is such that all three vector components of the magnetic field can be calculated in three measurement planes at 1.5 cm, 5 cm, and 10.5 cm above the Dewar bottom, respectively. The SQUID magnetometer channels have a typical white noise level of less than 2.3 fT/square root of Hz1/2 at 1 kHz.

Electromagnetic Fields↗
PubMed2004

Oesophageal transport of solid dosage forms depends on body position, swallowing volume and pharyngeal propulsion velocity.

Knowledge about transit of solid dosage forms (SDF) in the gastrointestinal tract is incomplete. Detection of magnetically marked capsules (MMC) via superconducting quantum interference device (SQUID) allows monitoring of oesophageal transport of SDF with high tempospatial resolution. The aim of the study was to investigate the influence of body position, volume at swallowing, and oesophageal motility on orogastric transport of SDF. In 360 measurements we determined tempospatial characteristics of orogastric transit of SDFs by a SQUID device in six volunteers. They swallowed MMCs with various amounts of water in upright and supine position with and without simultaneous oesophageal manometry. Orogastric transit time, oesophageal transport velocity and rate of oesophageal retention of SDF depend on swallowing volume and body position at all experimental conditions. At 50 mL water bolus and in upright position, the retention rate depends on the pharyngeal propulsion velocity, and the transport velocity of MMCs in the oesophageal body are faster than the propulsive oesophageal contractions. Body position, swallowing volume and pharyngeal propulsion velocity markedly influence the oesophageal transport of SDF. They should be taken in upright body position with at least 50 mL of water to minimize entrapment in the oesophagus.

Adult↗
PubMed2002

Imaging characteristics of different multichannel magnetocardiographic systems.

In this study a comparison of multichannel magnetocardiographic systems is performed with respect to the "detectable" information content. We investigate the lead-field matrices, the slope of the singular values and the source spaces of three different devices: the VectorView (Neuromag: magnetometer-gradiometer mixed device) of the BioMag Laboratory, Helsinki University Central Hospital (HUCH), the arrangement of electronically coupled magnetometers of the Physikalisch-Technische Bundesanstalt Berlin (PTB) and a virtual sensor geometry which was optimized for an improved slope of the singular values at the Institute of Biomedical Engineering, Karlsruhe.

Adult↗
PubMed2002

Investigation of gastrointestinal transport by magnetic marker localization.

The method of magnetic marker monitoring MMM with a biomagnetic measurement system allows the tracking of the transport of solid drug forms with high spatiotemporal resolution. This technique enables to display the path and the disintegration of the magnetic marked pharmaceutical dosage form via the decrease of its magnetic moment. The method was used to assess exogenous factor on the esophageal transport of orally administered solid drug forms in five healthy volunteers. In a drug delivery study we have applied the MMM to monitor the path of a tablet during the gastrointestinal passage and to visualize the disintegration in the small intestine by the magnetic moment of the tablet. The signal to noise ratio of the measurement data was improved by ICA filtering.

Acetaminophen↗