Abstract: In contrast to relatively expensive known methods for tumor diagnosis by means of serum tests, the serum to be investigated (or its albumin or globulin subfraction) are excited by an excitation radiation at least of a wavelength between 250 and 300 nm, and its fluorescence intensity is measured at predetermined emission wavelengths. From deviations of these measuring values from those of a standard or standard serum a conclusion can be drawn with respect to the presence of neoplastic diseases.

Abstract: One measurement each is obtained from two optical sensors of ion concentration, following which the measured values are used for empirical determination of the ionic strength of an electrolytic solution. The sensors contain the same indicator substance but differ with regard to surface modification, thus ensuring different responses to ionic strength in spite of identical excitation and fluorescence wavelengths and the resulting simplicity of the optical system.

Abstract: A device for equilibrating small quantities of a liquid reagent or a test solution with a gas-containing liquid or a gas in which at least part of the passage of the reagent leads through a hollow space that is separated by a permeable wall from a gas chamber which is closed, except for an inlet and an outlet opening, and which may be charged with the gas or gas-containing liquid. In order to ensure good mixing of the test liquid during equilibration, the hollow space carrying the liquid is configured as a tube or hose with one or more helical sections inside the gas chamber whose walls are permeable to the gas.

Abstract: In its initial position an input opening of a sample input device provides a seal against a funnel element which is directly connected to a feed pipe delivering standard media and to a valve-controlled air supply, and which has a feed opening cooperating with the input opening. Thus, in the initial position of the sample input device, the input opening and the feed opening at the funnel element together are part of a closed path for the additional media required for measurement and cleaning purposes, which will simplify the overall design of the apparatus.

Abstract: In order to produce a sensitive membrane electrode with high selectivity with respect to other anions and lipophilic ions or interfering substances, the membrane is based on an unplasticized polymer matrix whose content of electroactive component is between 50 and 90 percent by weight.

Abstract: In an O.sub.2 sensor element which contains a fluorescent indicator substance, a polymerized silicone polymer is used as a carrier material in which the indicator substance is incorporated in solubilized form and in an at least approximately homogeneous distribution. Solubilization of the indicator substance may essentially be performed in analogy to Friedel-Crafts alkylation of aromatics, which will increase solubility of the indicator substance in the polymer carrier without affecting quenching behavior.

Abstract: In an optical sensor used mainly for determining the partial pressure of O.sub.2 or CO.sub.2 in respiratory gas includes a sample measuring chamber through which sample medium to be analyzed flows or into which it is fed, a reference measuring chamber containing a reference gas or a reference liquid of constant composition, a light source, a unitary excitation filter positioned between the light source and first sides of both the sample measuring chamber and the reference measuring chamber, a single fluorescent sensor element on the second sides of both the sample measuring chamber and the reference measuring chamber, and first and second detectors for detecting the fluorescence radiation from the fluorescent sensor element respectively based on the light passing thereto from the sample measuring chamber and the reference measuring chamber.

Abstract: In a sensor element for determining the O.sub.2 content of a sample, comprising a fluorescent indicator substance which is embedded in a polymer carrier and with which the sample may be brought into contact, a fluorescence extinction sufficiently high for yielding useful measurement results is achieved by the use of plasticizer-compatible polymers as carrier materials which contain plasticizers in addition to the indicator molecules.

Abstract: For the simultaneous measurement of the concentrations of several substances a number of fluorescence measurements corresponding to the number of substances to be tested are performed using at least one fluorescent indicator which is non-specific relative to at least one of the substances to be tested, each fluorescent indicator having different quenching constants with regard to the individual substances quenching its intensities.From the known, unquenched fluorescence intensities of the fluorescent indicators employed, the quenched fluroescence intensities obtained by measuring, and from the quenching constants that are known, or rather, have been determined beforehand by graphical methods or calculation, the concentrations and/or concentration ratios of the individual substances are obtained.

Abstract: Fluorescence-optical indicator material is chemically bonded in a network structure permeating a carrier membrane of the sensor element. As this network structure is independent of the membrane and not chemically bonded thereto, the properties of the membrane and the indicator are not affected by the immobilization.

Abstract: Between a substance to be analyzed and a sensor there is placed at least one membrane, forming part of a sample vessel containing a sample to be analyzed and being permeable for a species depending on the substance to be analyzed. This membrane constitutes at least one wall of the sample vessel, through which the active sensor surface may be brought into contact with the substance to be analyzed. The sensor is designed as a separate unit which is movable relative to the sample vessel, with which its membrane may be brought into contact. For the purpose of measurement the sensor is contacted by the membrane stretching over the active sensor surface which in itself does not carry a membrane.In this way the sensor cannot be contaminated by the sample, and the device may be successfully used for series measurements.

Abstract: An analyzing apparatus for the analysis of liquid samples is provided with a single sample input unit and a serial sample input unit which may alternatively be connected to a joint evaluation unit by means of a change-over switch. This will permit the measurement of single samples during a serial sample run by interrupting the automated process, additional provisions ensuring an automatic return to the serial sample mode.

Abstract: An electrochemical measuring apparatus may be charged with an option of several media by providing a feeder part with the respective media connections, and by guiding a piece of pipe in a bore, which is sealed off and is movable relative to this feeder part. On its end facing away from a measuring chamber in the apparatus, the piece of pipe has a connection for additional media. Besides, it carries at least one circumferential bore which may be brought to coincide with at least one of the input openings into the bore connecting to the feed lines, by means of a relative motion - preferably controlled via a stepping motor - between the pipe piece and the above bore.

Abstract: Method for making an electrode having an axial capillary bore with an intersecting bore. An extensible tube is inserted in the axial bore and a polymerizable mixture is inserted in the intersecting bore and permitted to polymerize against the tube which is stretched to facilitate removal of the tube. The tube is selected to swell under the action of the solvent and the tube is filled with solvent.

Abstract: A method and apparatus for determining the systolic time intervals from the electrocardiogram (ECG) wherein initially there is detected at least the point in time of the Q-wave in the ECG. Thereafter there is determined the time point for the start of the second cardiac sound and then there is determined the start of the ascent of the pulse curve as well as the position as a function of time of the dicrotic depression. Then there is checked the timewise correlation of the signals with respect to one another, and finally, there is checked whether the timewise spacing of characteristic points of the signals are within predetermined tolerances. The apparatus for performance of the method contains analogue signal processing means for ECG-signals, analogue signal processing means for cardiac sound signals, analogue signal processing means with which there is operatively associated a computer and output device.

Abstract: A measuring chamber contains contact devices between each of which the electric resistance is measured before the actual analysis of the blood gases begins so that erroneous measurements are avoided if the measuring chamber is not completely filled with a blood specimen or to enable blood gas analysis to be carried out with small quantities of specimen material.

Abstract: A measuring circuit for use with an active polarized electrode, a reference electrode and a diaphragm which separates the solution to be examined from the electrolyte in which the electrodes are immersed. The output signals from the polarized electrode and from the reference electrode are processed as follows. The respective electrode is connected to one of the inputs of a respective operational amplifier (OA1, OA2) which serve as current voltage converters. The outputs of these amplifiers are then connected to a third operational amplifier (OA3) which detects the prevailing current difference in the electrode currents and initiates a necessary correction.

Abstract: The measured values are calculated from the following equation: ##EQU1## in which X.sub.1, X.sub.i+1, X.sub.i+2 are three values of signals obtained from one electrode measured successively at equal intervals of time, namely after a latent time .tau. has elapsed.The time required for calibration and measurement in the course of a blood gas analysis can be substantially reduced by the consistent application of this procedure for obtaining the measured value for each calibration and measurement.

Abstract: A device for the withdrawal of blood, especially for the removal of blood from arteries, comprising a puncture needle with which there is connected at least one capillary located in a substantially cylindrical jacket at which there is mounted the puncture needle.

Abstract: A multi-wire oxygen electrode and method of manufacturing the same, said electrode having a reactive electrode surface formed by a glass electrode tip having an end surface and a number of electrode wires are distributed in the end surface of the electrode tip along a circle. The cross-sectional surfaces of said electrode wires are freely exposed in such end surface and the electrode wires are fused in the electrode tip and electrically conductively connected with a cathode wire arranged in a glass sleeve. There is provided a substantially semi-spherical shaped support surface having an apex, said support surface being coaxially arranged with respect to the electrode tip, and said cathode wire being held in the electrode tip at the apex of the support surface.