US 7,248,909 B2Granted

Method and apparatus for dynamically monitoring multiple in vivo tissue chromophores

AssigneeThe Regents of the University of California

InventorsJangwoen Lee, Bruce J. Tromberg, Albert E. Cerussi, Matthew Brenner

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Abstract

A device and method utilizes a broadband diffuse optical spectroscopy (DOS) system to dynamically calculate the concentrations of multiple chromophores in vivo using a non-invasive probe. The device and method permit dynamic monitoring of multiple in vivo tissue chromophores non-invasively with sensitivities necessary for effective therapeutic monitoring. The device includes a probe containing first and second source optical fibers as well as first and second detector optical fibers. The probe is placed adjacent to a sample of interest and detects reflected light which is passed to a proximally located detector and spectrometer. The concentrations of multiple chromophores are determined in real time. In a preferred embodiment, the multiple tissue chromophores include at least two of methemoglobin (MetHb), deoxyhemoglobin (Hb-R), oxyhemoglobin (Hb-O2), water (H2O), and methylene blue (MB). The device and method can be used quantify and monitor methemoglobin formation in subjects suffering from methemoglobinemia.

Claims17

Dependent claims

A method of monitoring methemoglobinemia in a subject comprising the steps of:

providing a broadband diffuse optical spectroscopy device, the device having a first light source emitting light at a plurality of wavelengths and second light source comprising a broadband light source, first and second source optical fibers optically coupled, respectively, to the first and second light sources, first and second detector optical fibers optically coupled, respectively, to a detector and a spectrometer, the broadband diffuse optical spectroscopy device including a probe that is configured for placement adjacent to the subject's skin;
radiating the subject with light from the first light source;
detecting intensity-modulated diffuse reflectance signals using the detector;
determining absorption and reduced scattering coefficients at each wavelength of the first light source;
radiating the subject with radiation from the second light source;
acquiring broadband reflectance measurements using the spectrometer;
determining absolute reflectance spectra based on the broadband reflectance measurements and the absorption and reduced scattering coefficients;
calculating μa spectra from the absolute reflectance spectra;
and
determining the concentration of methemoglobin, deoxyhemoglobin, and oxyhemoglobin, based on wavelength-dependent extinction coefficient spectra;
calculating a percentage of methemoglobin based on the formula [MetHb]/([Hb-O2]+[Hb-R]+[MetHb]);
and
displaying the percentage of methemoglobin on a computer display connected to the broadband diffuse optical spectroscopy device.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/103,963Filed 12 Apr 2005 · us provisional application
Priority: 13 Apr 2004
Published: US 2005/0228246 A113 Oct 2005
Granted: 24 Jul 2007
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

A61B 5/14551
Using optical sensors, e.g. spectral photometrical oximeters: for measuring blood gases
A61B 5/412
Detecting, measuring or recording for evaluating the immune or lymphatic systems: detecting or monitoring sepsis
G01N 21/31
Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands:…
G01N 21/49
Scattering, i.e. diffuse reflection: within a body or fluid