Device and method for monitoring body fluid and electrolyte disorders
First Claim
1. A device for determining body fluid-related metrics, the device comprising:
- a processing device configured to process a signal indicative of optical radiation received from a tissue location to compute the body fluid-related metrics, wherein the body fluid-related metrics comprise absolute volume fractions of water in extravascular and intravascular bodily tissue compartments and differences between intravascular fluid volume and extravascular fluid volume fractions.
3 Assignments
0 Petitions
Accused Products
Abstract
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, 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-herne proteins, lipids and water in tissue. The difference between the fraction of water in the intravascular fluid volume and extravascular fluid volume compartments are also determined.
-
Citations
51 Claims
-
1. A device for determining body fluid-related metrics, the device comprising:
a processing device configured to process a signal indicative of optical radiation received from a tissue location to compute the body fluid-related metrics, wherein the body fluid-related metrics comprise absolute volume fractions of water in extravascular and intravascular bodily tissue compartments and differences between intravascular fluid volume and extravascular fluid volume fractions. - View Dependent Claims (2, 3, 4, 5)
-
6. A device for determining body fluid-related metrics, the device comprising:
a processing device configured to process a signal indicative of optical radiation received from a tissue location to compute the body fluid-related metrics, the body fluid-related metrics comprising percent body water and a water balance, where the water balance is an integrated difference between a water fraction in blood and a water fraction in extravascular tissue.
-
7. A device for determining an absolute volume fraction of water within human tissue, the device comprising:
a processing device configured to process a signal indicative of optical radiation received from a tissue location to compute the absolute volume fraction of water, wherein the processing device receives and compares at least two sets of optical measurements, where the at least first set of optical measurements corresponds to the detection of the optical radiation whose absorption is primarily due to water, lipids and non-heme proteins, and where the at least second set of optical measurements corresponds to the detection of the optical radiation whose absorption is primary due to water, and where a comparison of the at least two optical measurements provides a measure of the absolute volume water fraction within the tissue location.
-
8. A device for determining a difference between an intravascular fluid volume and an extravascular fluid volume, the device comprising:
a processing device configured to process a signal indicative of optical radiation received from a tissue location to compute the difference between an intravascular fluid volume and an extravascular fluid volume, wherein the processing device receives and compares at least two sets of optical measurements from at least two different wavelengths, where absorption of light at the at least two different wavelengths is primarily due to water that is in vascular blood and in extravascular tissue, and where a comparison of the at least two measurements provides a measure of a difference between the fractions of water in the blood and the tissue location.
-
9. A method for determining body fluid-related metrics in a human tissue location, the method comprising:
processing a signal indicative of optical radiation received from the tissue location to compute the body fluid-related metrics via a processing device of a fluid monitor, wherein the body fluid-related metrics comprise absolute volume fractions of water in extravascular and intravascular bodily tissue compartments and differences between intravascular fluid volume and extravascular fluid volume fraction, wherein the processing comprises; measuring at least two sets of optical measurements based on received optical radiation of at least two wavelengths; combining the at least two sets of optical measurements to form either a single ratio of the received optical radiation, a sum of ratios of the received optical radiation, or ratios of ratios of the received optical radiation to form combinations of received optical radiation; and determining the metrics from the combinations.
-
10. A device for determining body fluid-related metrics, the device comprising:
a processing device configured to process a signal indicative of optical radiation received from a tissue location to compute the body fluid-related metrics, wherein the optical radiation comprises a plurality of spectral wavelengths chosen to be preferentially absorbed by tissue water, non-heme proteins and lipids, where preferentially absorbed wavelengths are wavelengths whose absorption is substantially independent of individual concentrations of non-heme proteins and lipids, and is substantially dependent on a sum of the individual concentrations of non-heme proteins and lipids. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
-
27. A device for determining body fluid-related metrics, the device comprising:
a processing device configured to process a signal indicative of optical radiation received from a tissue location to compute the body fluid-related metrics, wherein the body fluid-related metrics comprises a tissue water fraction, and where the tissue water fraction (fw) is determined such that - View Dependent Claims (28, 29, 30, 31, 32)
-
33. A device for determining body fluid-related metrics, the device comprising:
a processing device configured to process a signal indicative of optical radiation received from a tissue location to compute the body fluid-related metrics, wherein received optical radiation comprises a plurality of spectral wavelengths chosen to ensure that the computed body fluid-related metrics are substantially insensitive to scattering variations and such that the optical path lengths through the tissue location at the wavelengths are substantially equal. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40, 41, 42)
-
43. A device for determining body fluid-related metrics, the device comprising:
a processing device configured to process a signal indicative of optical radiation received from a tissue location compute the body fluid-related metrics, wherein the received optical radiation comprises a plurality of spectral wavelengths chosen to ensure that the received optical radiation from the tissue location is substantially insensitive to temperature variations, wherein wavelengths of the received optical radiation are temperature isosbestic in the water absorption spectrum or wherein the signal is processed in such a way that temperature dependencies of individual wavelengths of the received optical radiation is substantially cancelled when computing tissue water fractions. - View Dependent Claims (44, 45, 46, 47, 48, 49, 50, 51)
Specification