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R Schittenhelm

Publications and source records attributed to R Schittenhelm.

5 recordsLinked to original sources
PubMed1989

[ECG changes caused by the effect of static magnetic fields of nuclear magnetic resonance tomography using magnets with a field power of 0.5 to 4.0 Telsa].

ECG-alterations under the influence of static magnetic fields were investigated in phantoms (1.5 Tesla), animals and volunteers (4.0 Tesla), as well as in 12 patients (0.5, 1.0, and 1.5 Tesla). Under the influence of static magnetic fields high- and low-frequency voltages are superimposed on the ECG. Motions of the electrical leads induce high-frequency waves, which can alter the ECG to the extent that only the QRS-complex can be recognized. Electrolytes moved by the blood stream in static magnetic fields also induce voltages (Hall-effect) which, according to the patient's position, result in ST-segment- and partial T-wave-elevations or depressions. All ECG-alterations are reversible after exposition to the static magnetic field. Rhythm disturbances do not occur. The results indicate that static magnetic fields up to 4.0 Tesla do not have permanent adverse effects on the human ECG.

Adult↗
PubMedDate not supplied

Biomagnetic imaging.

Generation, transfer and reception of sensory information in the human body is established by electric events, a multitude of current pulses propagating electric events, a multitude of current pulses propagating through the nervous system and muscles. Today, medical diagnosis is based on recording the electric potentials created by these pulses--ECG or EEG--with electrodes on the skin or invasively with catheters. In addition, the magnetic field generated simultaneously allows a sufficiently precise localisation of single events as well as current trains. By fusion with three dimensional anatomic images, sources and propagation of electrical activity can be visualised in biomagnetic images with resolution in space as well as in time. These prospects resulted in a continuing interest in biomagnetism (BM) even though specific equipment for the detection of magnetic field patterns was not available. Technological progresses recently allowed systems containing many, integrated, highly sensitive sensors to be developed. These are quite large enough to cover the area over the human skull and heart. The registration of magnetic field patterns in one shot allows localisation of sporadic events and reduces the time for data acquisition to a few minutes. In addition to explaining the characteristics of BM fields and modern techniques for their registration this paper focuses on the results of pilot studies, performed during the last 2 years with multichannel systems. It was shown that sufficient correlation exists to normal physiology. Pathology was studied mainly in heart diseases and in epilepsy.

Diagnostic Imaging↗