1109 results about "Spectrophotometry" 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.

Method and apparatus of spectrophotometry or the like on extremely small liquid samples in which a drop is held between two opposing surfaces by surface tension and one surface is controllably moved toward and away from the other. To provide and transmit exciting energy through the drop for measurement, the optical fibers go through a surface and are finished flush with its surface. One of the surfaces can be swung clear of the other for easy cleaning between tests.

A method and system are provided for characterizing a reservoir of interest by comparing measured downhole fluid analysis measurement data with predicted downhole fluid analysis measurement data for the corresponding depth within the reservoir. The downhole fluid analysis measurement data may comprise the results of compositional analysis, gas-oil ratio measurements, and spectrophotometry measurements. The compositional analyses may be delumped to characterize the compositional components of the downhole fluid and equations of state may be used to predict compositional gradients and fluid properties with depth. The method and system enable the user to characterize a reservoir as to its states of compartmentalization and equilibrium.

Embodiments of the present invention relate to a system and method for practicing spectrophotometry using light emitting nanostructures. Specifically, embodiments of the present invention include a physiologic sensor comprising a sensor body configured for placement adjacent pulsatile tissue of a patient, a first light emitting nanostructure device configured to emit light at a first wavelength through the pulsatile tissue, a second light emitting nanostructure device configured to emit light at a second wavelength through the pulsatile tissue, and a light detector configured to detect the light at the first wavelength and the light at the second wavelength after dispersion through the pulsatile tissue.

Methods for determining the state of charge of an electrolyte solution in a redox battery by optical absorption spectrophotometry are disclosed. The state of charge thus obtained may serve as a gauge for the amount of electro-chemical energy left in the system.

A method and system for characterizing asphaltene gradients of a reservoir of interest and analyzing properties of the reservoir of interest based upon such asphaltene gradients. The analysis employs a correlation that relates insoluble asphaltene concentration to spectrophotometry measurement data measured at depth.