Abstract: An electrochemical-enzymatic sensor for the determination of substances, in particular glucose, in body fluids, which possesses a good long-term stability, includes: a sensor electrode of electrocatalytically inactive carbon, a counterelectrode, a reference electrode, an enzyme-containing layer located before the sensor electrode, and a diaphragm of biocompatible, hydrophilic, oxygen-permeable material covering the enzyme layer toward the body fluid and retaining the enzyme.

Abstract: An electrocatalytic sensor in catheter type of construction for determining glucose in body fluids, especially in the blood, having the following features:a tubular body made of bio-compatible material that is subdivided into three sections,a sleeve-shaped reference electrode arranged between the first and the second, or between the second and the third section of the tubular body,a sleeve-shaped working electrode arranged--correspondingly--between the second and the third, or between the first and the second section of the tubular body, said working electrode having a slit extending in longitudinal direction over the full length,a hydrophilic membrane stretched over the working electrode whose ends are guided through the slit into the interior of the electrode and which is held in the slit by a wedge made of bio-compatible material,a counter-electrode which seals the one end of the tubular body, andlead wires to the electrodes arranged within the tubular body which are brought to the outside through the othe

Abstract: An apparatus and method of electrochemically determining an oxygen concentration with an oxygen sensor that includes a working electrode. The working electrode has a potential profile that includes a first potential step (a first measuring potential), a second potential step (a second measuring potential) and a third potential step. A measuring period is provided at the first and second measuring potentials. The currents flowing at the first and second measuring potentials are calculated and integrated over time. One of the two measuring potentials may be varied, depending on the difference between the two integrals of the currents flowing at the first and second measuring potentials, until the two integrals equal 0. An oxygen concentration is then determined from the value of a potential which thereby results.

Abstract: A system for infusing medicine into the body of a patient includes an implantable infusion apparatus containing a dosing unit with a reservoir for the medicine and a medicine delivery pump for pumping doses of the medicine from the reservoir into the patient. The infusion apparatus also includes a sensor for sensing a parameter of the patient for controlling the dosing of medicine according to the sensed parameter. The dosing unit and the sensor are galvanically separable and are each provided with separate telemetry communication units for communication with an external programmer/controller. The external programmer/controller includes telemetry communication units for selectable communication with the dosing unit or the sensor or both simultaneously. The telemetry communication units of the external programmer/controller, the dosing unit and the sensor are constructed for bi-directional communication between the external controller and each one of the dosing unit and the sensor.

Abstract: The invention relates to implantable devices and materials, in which at least one part of the surface is provided with a tissue-plasminogen activator (t-PA). In this way, inflammatory reactions of the body and the formation of fibrous capsules, which ordinarily occur after implantation, are avoided or reduced.

Abstract: In a process for electrochemically determining the oxygen concentration, in particular in body fluids, by means of an oxygen sensor having a sensor electrode, an exact oxygen determination is possible if a potential profile having a plurality of potential stages is impressed on the sensor electrode, the first potential stage being in the range between -0.5 and -1.2 V (1st measuring potential), the second potential stage being in the range between -0.5 and -1.3 V 2nd measuring potential) and the third potential stage being about 0 V, referred in all cases to an Ag/AgCl reference electrode, and there being between the two measuring potentials a potential difference of .gtoreq.

Abstract: In the case of a reference electrode with a layer of silver chloride situated on a silver layer, the amount of silver ordinarily released while in use can be significantly reduced by providing the silver-chloride layer with a layer of water absorbing, ionically conductive material which projects out over the surface of the silver-chloride layer.

Abstract: An apparatus for electrochemically determining the partial oxygen pressure pO.sub.2 in a liquid measuring medium includes a measuring sensor having a working electrode and a counter-electrode. The electrodes are manufactured in thin-film technology and are arranged on a substrate in a measuring channel, to which the measuring medium and a rinse medium can be supplied in alternation. The measuring channel connects a device which controls the flow rate of the measuring medium to a lumen of a double lumen catheter. The rinse medium is suppliable to a second lumen of the double lumen catheter with reversible flow direction. Both lumens have a common orifice which can be introduced into the measuring medium. So-called poisoning of the electrodes in this arrangement is suppressed because the electrodes are flooded in alternation by the measuring medium in a measuring phase and by the rinse medium in a regeneration phase.

Abstract: An electrode for medical applications can be manufactured with different geometries, and particularly in the form of hollow bodies, by depositing pyrographite on a shaped body of glassy carbon. The deposition is achieved by means of the pyrolysis of hydrocarbons at temperatures ranging approximately from 1800.degree. to 2100.degree. C. After cooling, the pyrographite coating is removed from the shaped body and a pyrographite electrode is produced from the coating.

Abstract: The invention involves a method for determining the concentration of electro-chemically convertible substances in a solution by means of an analyzer equipped with a test electrode, so that a precise determination of the concentration, dependable over extended periods, is possible. The invention provides for a potential varying with time within a potential interval to be impressed on the test electrode, for an ac voltage of a predetermined amplitude and frequency to be superimposed on this potential, and for the real and/or imaginary portions of the impedance to be determined for at least one potential step, thus determining the concentration. The method is particularly suited for determining the concentration of glucose in body fluids.

Abstract: The electrochemical determination of the oxygen concentration, particularly in biological matter, is possible by means of an oxygen sensor with a measuring electrode and a counter electrode over long periods of time, even if the sensor is implanted, by taking the following measures; two potentials are cyclically impressed on the measuring electrode, with one potential (measuring potential) in the range -1.4 V.ltoreq..rho.Ag/AgCl.ltoreq.-0.4 V, and the other potential (recovery potential) in the range -0.2 V.ltoreq..rho.Ag/AgCl.ltoreq.+0.2 V; the dwelling time at the measuring potential is small as compared to the duration of the cycle; and the current flowing during the measuring period is evaluated as the measuring signal.