U.S. Philips Corporation

Compumedics Limited

Manfred H Fuchs

Ernst Brinkmeyer

Wolfgang Brennecke

Olaf H Dossel

Wolfgang Hoppe

Friedrich-Karl Beckmann

Hans-Aloys Wischmann

Robert Oostenveld

Rob Steenbrink

Stephen F Sands

Wilhelm Dargatz

The present invention involves the creation of an appropriate model and the use of that model to generate a best fit dipole represented by a vector (x, y, z). Once the best fit dipole is generated, a best fit field distribution and a field distribution of a modified dipole is created. Using a difference between the field distributions, a Singular Value Decomposition is used to compute the main axes of the confidence ellipsoids.

Method and system for displaying confidence intervals for source reconstruction

In one embodiment, the present invention includes an EEG system comprising of sensors which are utilized to gather an electromagnetic signal from a patient; a signal processing system; and a computer system. The computer system is configured to support multiple threads of execution. The computer system initiates a first thread of execution, a measurement module, where the data is filtered and in some cases averaged. Typically, the data is filtered for a particular latency period. Once the data has been filtered and averaged, the result is given to a second thread of execution, the source reconstruction module, which then proceeds to generate a source reconstruction for the trial. The measurement module then acquires and processes new electromagnetic data from a new trial while the source reconstruction is being performed on the most recent trial.

Online source reconstruction for eeg/meg and ecg/mcg

A device for determining the spatial position of a sensor element (3) which is spatially displaceable relative to a reference element (1), includes three coils (4, 5, 6) which are arranged in the sensor element (3), consist of at least one wire turn, and are wound about a common center (7), at least three coils (2) which are arranged in the reference element (1) in spatially remote positions and consist of at least one wire turn, a current generator (11) for exciting the sensor element coils (4, 5 6) or the reference element coils (2) by means of a presettable excitation alternating current, and a processing circuit (15) for the voltages induced in the reference element coils (2) or in the sensor element coils (4, 5, 6). The processing circuit includes an arithmetic circuit which calculates, on the basis of the induced voltages, the distance coordinates x.sub.m, y.sub.m and z.sub.m of the center (7) of the sensor element coils (4, 5, 6) in a coordinate system associated with the reference element (1), as well as a feedback circuit (13) which controls the excitation currents in dependence on the amplitude of the induced voltages.

Device for determining the spatial position of a sensor element which is

The invention relates to a method of determining the spatial field distribution and/or the spatial position of a useful field source, producing said field distribution, by means of a multichannel field measuring device which comprises a plurality of spatially distributed sensors which produce measured values which contain on the one hand useful measured values stemming from the useful field source and on the other hand noise measured values stemming from at least one noise field source, correction values being formed and superposed on the measured values so that compensated measured values are obtained which are compared with similarly compensated, mathematically derived reference values which are produced by a fictitious reference field source by means of the field sensors, the reference field source being determined for which the pattern of compensated reference values corresponds best to the pattern of compensated measured values.

Method of determining the spatial field distribution

Heterodyne optical time domain reflectometer (OTDR) for determining the attenuation behavior of a monomode waveguide (test waveguide) by measurement of the backscattered parts of light pulses transmitted in said waveguide. An acousto-optic modulator (AOM) which deflects the transmission beam from a laser into the waveguide to be tested at a light frequency which is modulated with the acoustic frequency when the AOM is acoustically energized in a pulse mode. The light pulses backscattered from the test waveguide are superimposed on a local oscillator beam (LO) constituted by the laser beam which traverses the AOM when the AOM is not energized. The optical system losses are reduced in that the superposition is realized in a passive coupler, particularly a fibre coupler (10, 26).

Heterodyne optical time domain reflectometer

An optical multi-port element with an acousto-optical modulator (AOM) has at least two monomode optical waveguide connections, at one side thereof. The end surfaces of the waveguides disposed in the focal plane of a lens situated between the optical waveguides and the acousto-optical modulator. In order to obtain a construction which can be adjusted in a simple manner and which has low attenuation, with a small overall length, it is provided that at least one side of the AOM (1) a single lens (2,3,31) is disposed with its optical axis aligned to the transmission axis of the AOM (1), and that the optical wave-guides (4 to 6, 18 to 20 or 27,28) are disposed with their axes parallel to one another and spaced from the optical axis of the lens (2,3,31) in such a manner that parallel beams (14 to 17), leading from the lens (2,3,31) to the AOM (1), are directed to the active region of the AOM (1) at the Bragg angle to the optical axis.

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Hamburg, Germany

Manfred H Fuchs