Abstract: A device for measuring at least one measurand is disclosed which comprises a sensor device with at least one sensor and, via at least one medium-carrying detection path, can be connected to at least one of a plurality of devices outputting at least one flow of a medium to be captured. The at least one sensor is arranged to selectively detect at least one measurand with respect to at least one medium flow output by one of said plurality of devices. A system which includes the sensor device in a centralized way further comprises at least one device outputting the flow of the medium to be measured at least one outlet, wherein one of the devices can be selectively selected and can be connected to the sensor device for a predetermined period of time if several devices outputting a medium flow are connected to the sensor device for measuring at least one measurand.

Abstract: A method for calibrating a measurement signal and/or for tracking a quantitative variable comprises the measuring of an analyte which exists in a solution with a certain concentration and has predetermined decay kinetics and the generating of a continuous measurement signal having decay kinetics at least corresponding to those of the analyte. The decay kinetics of the measurement signal and the decay kinetics of the analyte are correlated using at least one predetermined calibration point of both decay curves. Subsequent concentration values of the analyte are then calculated from the measurement signal.

Abstract: A device for measuring at least one measurand is disclosed which comprises a sensor device with at least one sensor and, via at least one medium-carrying detection path, can be connected to at least one of a plurality of devices outputting at least one flow of a medium to be captured. The at least one sensor is arranged to selectively detect at least one measurand with respect to at least one medium flow output by one of said plurality of devices. A system which includes the sensor device in a centralized way further comprises at least one device outputting the flow of the medium to be measured at at least one outlet, wherein one of the devices can be selectively selected and can be connected to the sensor device for a predetermined period of time if several devices outputting a medium flow are connected to the sensor device for measuring at least one measurand.

Abstract: Methods and apparatus are disclosed for determining a substance in a fluid excreted/extracted from the body or spent dialysate, e.g., for determining a quality measure for the dialysis, such as the concentration of selected toxic substances, and/or for determining a removed total quantity of uremic toxins during a dialysis with a dialysis apparatus. A concentration of a substance in the fluid may be determined by: detecting, by an absorption sensor, a first extinction signal of the fluid at an analysis wavelength at a defined first pH value of the fluid; adjusting, by a pH adjusting device, a second pH value of the fluid which differs from the first pH value; detecting, by the absorption sensor, a second extinction signal of the fluid at the analysis wavelength at the second pH value; and processing/comparing the two extinction signals for the first and the second pH values and determining an absolute concentration of the substance dissolved in the fluid.

Abstract: Methods and apparatus are disclosed for determining a substance in a fluid excreted/extracted from the body or spent dialysate, e.g., for determining a quality measure for the dialysis, such as the concentration of selected toxic substances, and/or for determining a removed total quantity of uremic toxins during a dialysis with a dialysis apparatus. A concentration of a substance in the fluid may be determined by: detecting, by an absorption sensor, a first extinction signal of the fluid at an analysis wavelength at a defined first pH value of the fluid; adjusting, by a pH adjusting device, a second pH value of the fluid which differs from the first pH value; detecting, by the absorption sensor, a second extinction signal of the fluid at the analysis wavelength at the second pH value; and processing/comparing the two extinction signals for the first and the second pH values and determining an absolute concentration of the substance dissolved in the fluid.