Abstract: An apparatus for determining the flow of matter passing through a boundary surface, which is provided with at least one sensing layer corresponding to the boundary surface, and presents a known or predetermined, finite resistance to the material flow, and wherein an optical indicator is provided in the sensing layer for obtaining a first measured value of a quantity dependent on the mean concentration of matter in the sensing layer, and wherein a second measured value of this quantity is known on one side of the sensing layer, or can be determined by means of another optical indicator provided in a second sensing layer, and, further, wherein an evaluation unit is provided for inferring the material flow from the difference of the two values measured.

Abstract: A two-channel sampling needle is designed for withdrawing body fluids, such as blood or tissue fluid, has two essentially parallel cannulas, the first cannula being provided with an insertion needle which may be removed after the sampling needle has been introduced, its sharpened end projecting beyond the end of the first cannula. At the distal end of the sampling needle the second cannula has at least one connecting opening into the first cannula. A mounting part of the sampling needle is provided with fittings for the two cannulas and with a separate opening plugged by a flexible stopper for removal of the insertion needle.

Abstract: A dialytic probe is provided with an insertion needle sharpened at one end, which is surrounded by a flexible plastic cannula, and may be removed after introduction of the probe. The plastic cannula is covered at least partly by a tubular dialyzing membrane which is bonded to the plastic cannula at the distal end and to a handle at the other end, thus forming a fluid-tight seal. The space between the plastic cannula and dialyzing membrane is divided along the length of the probe, such that two passages or lumens of essentially crescent-shaped cross-section are formed, with a flow-connection at the distal end of the plastic cannula, and with a connection to one of separate ingoing and outgoing lines each. The lumen of the plastic cannula may be connected to a drug feeder line. The handle holds the ingoing and outgoing lines and a potential drug feeder line of the probe.

Abstract: In a sensor arrangement for direct or indirect optical determination of physical or chemical parameters, in human and animal bodies, the sensor arrangement including an indicator cell which is permeable to the chemical substance or physical quantity to be measured and which contains one or more indicators, a radiation source supplying the excitation radiation for the indicator, and a detector for detection of the response radiation emitted by the indicator, the indicator cell is configured as a capsule which may be introduced into body cavities, such as mouth, nose, stomach, intestine, blood vessels, bronchial tubes, urinary bladder, or which may be implanted in the tissue, and the material used for this capsule is transparent to excitation radiation and to the response radiation emitted by the indicator in the range of wavelengths between 600 and 1,300 nm, and the material of the capsule, or rather, its outer layer, is bio-compatible.

Abstract: In order to simultaneously determine the concentrations of different analytes in several places in a tissue by means of a thin, biocompatible tube or cannula which is inserted into the tissue, the tube is provided with several areas along its length which contain either identical or different optically excitable and readable, preferably luminescence-optical, indicating substances for measuring the local distribution of one parameter, such as O.sub.2 concentration or O.sub.2 partial pressure, or for simultaneous measurement of at least two different parameters, e.g., pO.sub.2, pCO.sub.2 or pH.

Abstract: Method for analyzing gaseous or liquid samples, utilizing a one-way measuring element with a measuring channel containing at least one optical or electrochemical sensor and being provided with sealing elements on either end. In order to obtain accurate measurements in a simple manner the proposal is put forward that for measuring purposes a storage medium in the measuring channel be replaced by a separating medium which should then be replaced by the sample. Sample and storage medium will remain in the measuring element when it is discarded.

Abstract: A method for the continuous and reversible determination of the concentration of an enzyme substrate such as glucose in an specimen, wherein the specimen is brought into contact with a corresponding enzyme selected from oxidases and oxygenases and to which a flavin coenzyme (FMN, FAD) is bonded, the flavin coenzyme changing to a reduced form by the enzyme substrate and to an oxidized form by molecular oxygen dissolved in the specimen, and the change in the fluorescence spectrum, produced by means of the reduction of the flavin coenzyme, is measured.

Abstract: A device for the sampling of body fluids using a hollow needle (6), is provided with a storage system (3) with several separate sample containers (4) placed on a movable carrier (9). The containers (4) which are sealed by puncturable membranes (5) so as to be gas-tight, will receive collected fractions of the body fluid at given intervals, a device (7) connected to a control unit (2) being provided, by which the hollow needle (6) is positioned over each sample container (4) in turn and is inserted through the membrane (5) into the sample container. The sampling device 1 is configured as a two-channel cannula (18), one (19) of whose channels is connected via a first connecting tube (25) to the hollow needle (6) used for insertion into the sample containers (4), while its other channel (20) is connected via a second connecting tube (26) to a pump (8'; 21) operated by the control unit (2).

Abstract: A device for measuring blood pressure includes a sensor arrangement which is releasably attached to the exterior of a body and which is electrically conductively connected with electronic circuit. The sensor arrangement and the circuit are configured to determine, in at least one measuring region of the body, a valve which is a measure for a variable that changes periodically over time in the rhythm of the pulse beat and which is correlated with the blood pressure. This variable may, for example, be the flow velocity and/or flow quantity and/or the volume of the arterial blood and/or a cross-sectional dimension and/or the flow cross section area of an arterial blood vessel. The sensor and circuit further determine a value which is a measure for the pulse wave velocity. By linking the two values together and including at least one calibration value, at least one value that is characteristic for of the blood pressure (preferably including at least the systolic blood. pressure) can be determined.

Abstract: An indicator for use in a luminescence-optical configuration for continuous and reversible measurement of the pH of a sample within a relevant measuring range (M), whose luminescence decay time .tau. is dependent on the pH of the sample, is characterized by the following properties. The pK.sub.a value of the acidic or basic indicator is in the relevant measuring range when the indicator is in its electronic ground state (S.sub.0). The protonation rate k.sub.p of the base, or deprotonation rate k.sub.dp of the acid in the excited state (S.sub.1, X) of the indicator is lower than the decay rate k.sub.A of the excited state, and the luminescence decay times .tau..sub.S and .tau..sub.B of the acidic forms (AH*, BH.sup.+*) and the basic forms (A.sup.-*, B*) of the indicator are different from each other. If the pK.sub.a .tau. value of the indicator in its electronically excited state (S.sub.1, X) is within the relevant measuring range, the protonation rate k.sub.p of the base, or deprotonation rate k.sub.

Abstract: A system for measuring the saturation of at least one gas in blood has a sensor which is, intended to be placed on a living body. Light is emitted from the sensor and into the body at a light radiating zone. The sensor has a plurality of light receiving zones, serving to receive light backscattered in the body, which zones are at various distances from the light radiating zone. Light receiving means are also present, in order to measure the intensities of the light backscattered from the body and reaching the sensor in the various light receiving zones. The measuring system also has electronic circuitry, which upon measurement, based on a predetermined criterion, selects one evaluation zone from among the light receiving zones and evaluate the portion of the light detected in the evaluation range that varies periodically over time at the rate of the pulse frequency in order to detect at least one gas saturation of blood, in particular the oxygen saturation of blood.

Abstract: An analyzing device, in particular for examining body fluids, with a measuring module, at least one gas feed tube for a calibrating gas, a moistening device for the calibrating gas as well as a washing water tube connectable to the measuring channel of the measuring module, is simplified and improved in that the moistening device for the calibrating gas is integrated in the washing water conduit through a water inlet and a water outlet. The calibrating gas can be led over the water surface in the moistening device and moistened in this way.

Abstract: Electromagnetically actuated valve, comprising an actuating device, a movable plunger and a valve chamber with an opening for the medium passing through it, which opening may be closed by the plunger. In order to ensure safe functioning of the valve at small closing forces, the valve chamber is totally sealed against the actuating device and the movable plunger by means of a flexible diaphragm, the diaphragm being fitted into the housing along its circumference and being pressed against the edge of the opening by the movable plunger.

Abstract: In order to simplify manufacture of the interior electrode of a polarographic electrode with an electrically insulating shell containing a wire lead and carrying a reactive surface at its front end, which surface is formed by the free cross-sectional areas of wires arranged in the shell and in electrical contact with the wire lead, the wires and the site where they are connected to the wire lead are embedded in a plastic compound filling the front end of the shell.

Abstract: A device for determining the concentration of at least one substance in organic tissue includes a subcutaneous needle for insertion into the tissue and a pumping and suction unit which is controlled by a microprocessor and is used for delivering a perfusion fluid and draining it after its partial equilibration with the tissue. The device further includes a sensing unit connected to the microprocessor for determining the concentration of the substance to be analyzed and one or more marker variables. The perfusion fluid, a calibrating solution and at least one drug are provided in replaceable metering ampoules sealed with membranes, whose metering plungers can be actuated by a drive unit controlled by the microprocessor. The metering ampoules communicate with a master capillary leading from the pumping and suction unit to the subcutaneous needle; communication is established via capillary tubes piercing the membranes.

Abstract: In order to determine at least one parameter of interest in a living organism, a perfusion is directly introduced in the tissues. After its partial balancing by the tissue parameter of interest, the perfusion fluid is collected and analyzed for the parameter of interest, as well as for endogenous or exogenous marker properties indicative of the degree of interaction between the perfusion fluid and the tissue, in such a way that the parameters of interest can be determined with the help of such characteristic properties. Contrary to usual processes, used exclusively inside blood vessels or other body cavities filled with liquid, this process creates in the tissues, i.e. in the closed cellular structure, a previously inexistent cavity, in which the perfusion fluid introduced in the tissue interacts directly with the organic tissue, with no intervening membranes.

Abstract: For optical determination of the catalytic enzyme activity of a sample by means of enzyme reactants which are split under the influence of the enzyme to be measured, the enzyme reactant is placed at the end of an optical fiber and brought into contact with the sample to be determined. The measurements are carried out by observing the rate of change in spectral characteristics of the enzyme reactant, or its reaction products, resulting from the enzyme reaction. The method permits measurements of undiluted blood and in-vivo determinations of enzyme activities.

Abstract: A method for the quantitative determination of one or more chemical parameters of a sample medium employs a fluorescent agent which is not responsive to the parameter to be determined and which has an excitation spectrum and an emission spectrum, and a closely adjacent chromogenic agent which responds to the parameter of the sample medium to be determined by a change in its absorption spectrum the emission spectrum of the fluorescent agent at least partically overlapping the absorption spectrum of the chromogenic agent. The absorption maximum of chromogenic agent is shifted in accordance with the parameter to be determined, causing a reduction of fluorescence decay time t in the fluorescent agent, thereby enabling quantitative determination of the chemical parameter with improved long-term stability and infrequent calibrations.

Abstract: Method for analysing gaseous or liquid samples, utilising a one-way measuring element with a measuring channel containing at least one optical or electrochemical sensor and being provided with sealing elements on either end. In order to obtain accurate measurements in a simple manner the proposal is put forward that for measuring purposes a storage medium in the measuring channel be replaced by a separating medium which should then be replaced by the sample. Sample and storage medium will remain in the measuring element when it is discarded.

Abstract: A device designed for determining one or more medical variables in living organisms, comprises a part to be inserted into the tissue of the organism, which has an exchange channel with openings into the tissue. The device comprising a delivery unit connected with the exchange channel for the delivery of a perfusion fluid and its drainage after partial equilibration with the medical variable or quantity to be measured, i.e., preferably glucose concentration, and comparatively constant endogenous or exogenous marker variables. The device further comprising an analyzing unit for measuring the medical variable and one marker variable, and an evaluation unit for determining the actual concentration of the medical variable with the use of the marker variables.