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Biomedical subjects

H Reichenberger

Publications and source records attributed to H Reichenberger.

7 recordsLinked to original sources
PubMed1993

Experience with a multichannel system for biomagnetic study.

The components of the biomagnetic multichannel system Krenikon are described. The combination of biomagnetically yielded localizations with anatomic images gained from MR or CT is discussed as well as the enhancement of the signal-to-noise ratio by using a correlation technique. The overall localization accuracy is tested with technical phantoms. With volunteers measurements of auditory, visual and somatosensory evoked fields are performed to evaluate the system performance in vivo. Clinical studies were performed mainly with partners from the Universities of Erlangen-Nünberg and Ulm. The data acquisition time typically is 2-10 min which is tolerable both for the patient and the clinical staff. Electric potentials even with invasive electrodes can be recorded simultaneously with the magnetic fields. MEG gives important information for the presurgical diagnosis of epileptic patients and for the understanding of the epilepsy genesis. With MCG, centres of biologic excitation such as ventricular ectopies or accessory bundles in WPW syndrome have been successfully localized.

Biology↗
PubMed1992

Biomagnetic multi-channel systems. Principles and application in cardiology.

The non-invasive measurement of the extremely weak magnetic fields generated by heart and brain is motivated by the possibility of obtaining quantitative diagnostic information about electric function. Magnetic signals (MCG, MEG) are significantly less influenced by body tissue than the corresponding electric signals (ECG, EEG). Measurement of biomagnetic signals is performed by superconducting sensors, consisting of pickup coils and SQUIDs (superconducting quantum interference device) operating in liquid Helium. For clinical investigations a biomagnetic multi-channel system (KRENIKONR) has been designed. It uses a flat array of 37 magnetic field sensors and is operated inside a shielded room. Evaluation of biomagnetic signals by use of simple source and body models and in combination with anatomical data from 3D MR- or CT-images yields sequences of locations of electrical function with a spatial resolution of some millimeters and a time resolution better than one millisecond. More than three years of clinical studies have demonstrated the value of the method primarily in cases with localized functional pathologies. In cardiology this is pathologies of the cardiac conductive pathway, ectopies, and arrhythmias. Validation has been performed by catheter stimulation in volunteers, and by catheter mapping and nuclear medical methods in patients. Extension of modelling and evaluation to cases with distributed activity, e.g. ventricular excitation, is under investigation.

Electromagnetic Fields↗
PubMed1990

Multichannel biomagnetic system for study of electrical activity in the brain and heart.

The authors designed a multichannel system for noninvasive measurement of the extremely weak magnetic fields generated by the brain and the heart. It uses a flat array of 37 superconducting magnetic field-sensing coils connected to sophisticated superconducting quantum interference devices. To prevent interference from external electromagnetic fields, the system is operated inside a shielded room. Complete sets of coherent data, even from spontaneous events, can be recorded. System performance was evaluated with phantom measurements and evoked-response studies. A spatial resolution of a few millimeters and a temporal resolution of a millisecond were obtained. First results in patients with partial epilepsy and investigations of the cardiac conductive pathway indicate that biomagnetism is now ready for a systematic clinical evaluation. Interpretation of measurements was facilitated by highlighting biomagnetically localized electrical activity in three-dimensional digital magnetic resonance images.

Brain↗
PubMed1987

New generation shock wave lithotripsy.

Extracorporeal shock wave lithotripsy has been clinically successful for more than 5 years. Currently, several devices commonly termed second generation lithotriptors are under experimental or clinical trials. We present a prototype multifunctional urological table that uses a new mode of shock wave generation along with local coupling to the patient. The results of the first 400 treatments are presented after a brief description of pre-clinical experiments. The prototype has been in operation since March 1986. Particular attention is paid to adjuvant endourological measures, which all have been performed on the same table.

Animals↗
PubMed1984

[ECG-triggered NMR tomography of the heart].

The technique and scope of ECG-triggered NMR tomography of the heart are described. Correct attachment of the ECG electrodes and cables is important in order to avoid artifacts. The anatomical structure of the heart and mediastinum can be demonstrated with a clarity which has not been possible hitherto in all three planes (axial, frontal, sagittal). This results in considerable advantages when examining abnormal hearts, since it is possible to avoid the risk of contrast media.

Electrocardiography↗