Abstract: The invention relates to a method and apparatus for detecting artifacts in a bioelectric signal, especially in a frontal EEG signal. In order to accomplish an uncomplicated mechanism for detecting artifacts in clinical applications, an impedance signal is measured through a first electrode set attached to the skin surface in a measurement area of a patient's body, the impedance signal being indicative of the impedance of the signal path formed between individual electrodes of the set. Simultaneously with the impedance measurement, a bioelectric signal is acquired through a second electrode set also attached to the skin surface of the measurement area, and the time periods are determined during which the impedance signal fulfills at least one predetermined criterion indicative of the presence of artifact in the bioelectric signal. In one embodiment, the first and second electrode sets are formed by a common set of two electrodes.

Abstract: The invention relates to a method and apparatus for assessing the reactivity observable in a certain physiological signal, especially the EEG signal, of a comatose subject. In order to obtain an objective and a reliable measure of the reactivity automatically and without the presence of a trained EEG specialist, a time reference corresponding to a stimulus is detected and the physiological signal data obtained from the subject is aligned with the time reference. Two sets of values are determined for a measure indicative of the amount of irregularity in the physiological signal data, both sets including at least one value of the said measure and having defined positions with respect to the time reference in time domain. Based on the two sets, the apparatus determines whether reactivity is present in the physiological signal data.

Abstract: The invention relates to the determination of the clinical state of a subject. A respective adaptive transform is applied to at least one measurement signal acquired from the subject, each adaptive transform being dependent on previously acquired history data, and a diagnostic index is formed, which is dependent on the transformed measurement signal(s) and serves as a measure of the clinical state of the subject. In order to reliably evaluate the clinical state of a subject on a fixed diagnostic scale during changes in the state of the subject, some or all of the previously acquired history data on which an adaptive transform is currently dependent is replaced with other previously acquired history data when a predetermined event is detected. The predetermined event is indicative of a change in the respective measurement signal, and the introduction of the said other previously acquired history data sets the transform ready for the change.

Abstract: An electrode for obtaining a biopotential signal from the skin of a subject. The electrode comprises an adhesive element, an electrode body, an electrically conductive electrode pad, a sponge element, soaked with conductive gel, and means for skin abrasion. The means for skin abrasion comprises abrasion elements forming an integrated structure with the electrode pad, the abrasion elements being so dimensioned that the sponge element prevents the abrasion elements from touching the skin when biopotential signals are measured and enables mechanical contact between the skin and the abrasion elements when the electrode pad is pushed towards the skin. The electrode body is made flexible to enable intentional movement of the electrode pad relative to the adhesive element.

Abstract: The present invention concerns a catheter heating circuit for continuous cardiac output measurement. The circuit comprises a DC power source for supplying an operating voltage for the circuit, wherein the heating power from the heating circuit is fed to the catheter via an isolating transformer. Isolation is known per se and it is not described in detail. According to the invention the heating circuit further comprises means for generating a bipolar square wave with variable duty cycle, which square wave is supplied to said isolating transformer and further to the catheter filament.

Abstract: The invention relates to a patient cable for medical measurements performed in connection with Magnetic Resonance Imaging (MRI). In order to eliminate the risk of thermal injuries without compromising the signal-to-noise ratio more than what is required for patient safety, the patient cable comprises two successive cable elements having different resistance characteristics. The second cable element, which is connected by the first cable element to the patient, has a total resistance increased from a normal high-conductivity resistance value of a patient cable to suppress antenna resonances in the second cable element. The first cable element, which is connected to the electrodes on the skin of the patient, has a total resistance substantially greater than that of the second cable element to prevent electromagnetically induced currents from flowing to the patient and to prevent excessive heating of the cable by electromagnetic induction.

Abstract: The present invention discloses a grounding arrangement in a system using same connector for 5- and 12-lead connection in ECG-measurement. If 5-lead configuration is used, the connector elements of the 12-lead connection are used for grounding of lead wire shields. In the system according to the invention grounding of the lead wire shields is performed through current limiting element.

Abstract: Disclosed is a method for producing a magnetic stimulation effect and/or a fake magnetic stimulation effect in a biological tissue. According to the method, the real magnetic stimulation is effected by virtue of inducing an electromagnetic field in said biological tissue with a sufficiently strong field strength to essentially excite said tissue, and the fake magnetic stimulation is effected by virtue of inducing an electromagnetic field in said biological tissue with a field strength that is weaker than the electromagnetic field required for an essential excitation of said tissue.

Abstract: The present invention relates to a stimulator head of a magnetic stimulator used in the stimulation of living tissue such as the human brain. Such a stimulator bead comprises a stimulator head body (3) suited for mounting the stimulator head on the magnetic stimulator equipment, at least one coil (1) which is connected to said stimulator head body (3) and is designed suitable for generating a stimulating magnetic field, and conductors (7) for passing electric current from said magnetic stimulator into any of said at least one coil (1). According to the invention, the stimulator head includes a housing (2) which is connected to said stimulator head body (3) and is designed to enclose at least one air-tight space (5) which further separates each of said at least one stimulator coil (1) from the other parts of said housing (2) facing the object being stimulated.

Abstract: The invention relates to a method and a system for a medical monitoring system, in which method the functions of a patient are measured, and the change in the electric activity of the patient are observed. In the method, the electrocardiogram (EKG), electroencephalogram (EEG), and the impedance cardiograph signal (IKG) are being measured with one piece of measuring equipment.

Abstract: The present invention concerns a catheter heating circuit for continuous cardiac output measurement. The circuit comprises a DC power source for supplying an operating voltage for the circuit, wherein the heating power from the heating circuit is fed to the catheter via an isolating transformer. Isolation is known per se and it is not described in detail. According to the invention the heating circuit further comprises means for generating a bipolar square wave with variable duty cycle, which square wave is supplied to said isolating transformer and further to the catheter filament.

Abstract: The invention relates to a method and apparatus for examining and mapping the reactivity of and connections between different cortical areas. In the method an electromagnetic stimulus is induced in the interior parts of the head and the electromagnetic field generated around the skull is measured by electrical means (1). According to the method, the electromagnetic activity of the brain is measured using multichannel equipment, artefacts caused by the stimulus are eliminated from the signal containing the electromagnetic activity, a visualization of the activity changes in the measured signals is formed, and the areas of the head related to said activity generating said electromagnetic field are localized, or alternatively, the maximum of the sensitivity pattern of the multichannel activity measurement system is focused to a desired point.

Abstract: A mechanism for transporting a patient to a magnetic resonance unit. A coil seat is mounted on the upper surface of a lower bed and the lower bed is mounted for movement relative to a magnet. An upper bed is mounted for movement on the lower bed. In the positioning stage, the coil is located outside of the magnet and the upper bed carrying a patient is moved relative to the lower bed to position the patient in registry with the coil, such that a desired anatomical area is brought into the imaging area of the coil. This is followed by pushing the upper and lower beds as a unit into the bore of the magnet. As various coils can be positioned on the lower bed at a common positioning location, it is possible to employ a common electric connection to eliminate the need for separately attachable cables.