Abstract: In a process and devices or continuously measuring the concentration of an analyte in tissue. The tissue is provided with a hollow fiber having a pore size between the size of the analyte and the size of macromolecules, hollow fiber is perfused with a solution compatible with the tissue, and that solution is supplied from the hollow fiber through a reactor for the analyte. The reactor has a second hollow fiber having a pore size between the size of the analyte and the size of macromolecules, and the second hollow fiber is located in a container which contains macromolecular reactants for detecting the analyte and a signal producing system coupled therewith. The perfusion fluid is fed from the reactor to an eliminator for the analyte, whereby at least 95% of the remaining analyte is removed from the perfusion fluid and the perfusion fluid is reintroduced into said first hollow fiber.

Abstract: A wearable-type glucose sensor for continuously or intermittently determining the glucose content comprises a short hollow fiber (2) to be positioned in the subcutaneous tissue. This hollow fiber is connected via tubes (3,4) with component parts (5 . . . 12) located outside the body, such as a measuring unit (11). When a perfusion fluid containing the enzyme glucose oxidase is passed through the hollow fiber, a subcutaneous dialysis will take place in which some glucose dissolves in the perfusion fluid through the wall of the hollow fiber. This glucose is completely oxidized by the oxygen dissolved in the perfusion fluid in the presence of the glucose oxidase. By means of the measuring unit the resultant amount of H.sub.2 O.sub.2 or, preferably, the employed amount of O.sub.2 is determined, both of which are a measure of the subcutaneous glucose concentration.

Abstract: The invention relates to a device for the controlled release of one or more active ingredients to a liquid, particularly a controlled release pharmaceutical tablet obtained by compressing a mixture of two granulates in a weight ratio of 30:70 to 70:30, said granulates having particle sizes of 0.4-2.0 mm. One of the granulates, the restraining phase granulate, comprises one or more active ingredients dispersed in a matrix of an insoluble substance, and the other granulate, the housing phase granulate, comprises a soluble material and a penetration rate limiting material, one material optionally having both functions. In the compressed device, the granulates form two distinct phases, each of which is continuous. The housing phase fills large continuous pores in the restraining phase. A zero-order release rate can be obtained with the devices.