42 results about "Absolute volume" patented technology

A device and a method for measuring body fluid-related metrics using spectrophotometry to facilitate therapeutic interventions aimed at restoring body fluid balance. The specific body fluid-related metrics include the absolute volume fraction of water in the extravascular and intravascular tissue compartments, as well as the shifts of water between these two compartments. The absolute volume fraction of water is determined using algorithms where received radiation measured at two or more wavelengths are combined to form either a single ratio, a sum of ratios or ratio of ratios of the form log[R(λ1) / R(λ2)] in which the received radiation in the numerator depends primarily on the absorbance of water and the received radiation in the denominator depends primarily on the absorbance of water and the sum of the absorbances of non-heme proteins, lipids and water in tissue. The difference between the fraction of water in the intravascular fluid volume (“IFV”) and extravascular fluid volume (“EFV”) compartments are also determined using a differential method that takes advantage of the observation that pulsations caused by expansion of blood vessels in the skin as the heart beats produce changes in the received radiation at a particular wavelength that are proportional to the difference between the effective absorption of light in the blood and the surrounding tissue. This difference, integrated over time, provides a measure of the quantity of the fluid that shifts into and out of the capillaries. A mechanism for mechanically inducing a pulse is built into the device to improve the reliability of measurements of IFV−EFV under weak-pulse conditions.

A method and a device for acquiring a value of a defined reference point of a first variable which is measured by an incrementally measuring sensor of a motor vehicle are disclosed. The method includes the step of acquiring intermediate values of the defined reference point in at least two detection modules using at least one second measured variable, wherein each detection module is adapted to determine a value of the defined reference point of the first variable in a pre-defined driving situation. A quality level for each intermediate value is determined. The quality levels of the intermediate values are compared. The value of the defined reference point is determined from the acquired intermediate values in accordance with a result of the compared quality levels.

The invention belongs to the technical field of biomedical engineering, and is characterized in that: the sensor is composed of two photoelectric receiving tubes and at least three light sources with different light-emitting wavelengths, based on the different spectral characteristics of oxygenated and reduced hemoglobin and tissue background in tissue oxygen metabolism, According to the law of light absorption and scattering in tissues, the concentration of oxygenated and reduced hemoglobin in local tissues is calculated. The light sources with at least three wavelengths and the two photoelectric receiving tubes are arranged in a straight line at a certain distance, and the light sources can respectively emit red light and near-infrared light. It can sensitively detect the absolute amount of oxygenated and reduced hemoglobin in human tissue.