Spectroscopy illuminator with improved delivery efficiency for high optical density and reduced thermal load

• US 20040039274A1
• Filed: 08/29/2003
• Published: 02/26/2004
• Est. Priority Date: 04/09/2002
• Status: Active Grant

• Current Assignee: JB IP Acquisitions LLC
• Original Assignee: Spectros Corporation (AliphCom Corp.)
• Inventors: Benaron, David A., Parachikov, Ilian H.
• Granted Patent: US 7,062,306 B2
• Time in Patent Office: Days
• US Class Current: 600/342
• CPC Class Codes: A61B 1/00165 with light-conductive means, e.g. fibre optics A61B1/07 takes precedence
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/14558 by polarisation
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/42 Detecting, measuring or recording for evaluating the gastrointestinal, the endocrine or the exocrine systems A61B1/00, A61B5/4857, A61B5/486, A61B5/4866, A61B5/4869 take precedence
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01N 2201/062 LED's

Abstract

An improved illuminator for generating broadband light, and for delivering the light to a sample with an improved delivery efficiency, for higher optical density and/or reduced thermal transfer, than achieved with conventional halogen bulb sources. The illuminator enables spectroscopic analysis in thermally-sensitive or spatially-constrained environments. A phosphor-coated broadband white LED and integrated collimating optics produces a continuous, collimated broadband light beam from 400 nm to 700 nm, which is then transmitted through space to a sample region, such as a living tissue in vivo. A method and system for measuring oxigeneration of mucosal or subsurface tissue is also described.

Claims

1. A method of monitoring tissue oxygenation involving:

(a) placing an oximeter probe on, in or near a living tissue at mucosal or subsurface tissue site;

(b) illuminating the tissue with a broadband visible illumination;

(c) monitoring light returning from the subsurface or mucosal tissue cite, said light comprising at least one set of visible wavelengths from 400 to 700 nm; and

(d) determining the tissue hemoglobin oxygenation index saturation.

7. The method of claim 1 wherein said probe is selected from the list of probes consisting of catheters, clips, optical fibers, needles and wands.

2. The method of claim 25 wherein said tissue site is selected from the list of tissues consisting of oropharynx, nasopharynx, esophagus, stomach, duodenum, ileum, colon, or other gastrointestinal mucosal or superficial tissue.

3. A method of monitoring tissue oxygenation involving:

(a) illuminating the tissue with a broadband visible illumination having shallow-penetrating wavelengths shorter than 600 nm;

(b) monitoring shallow-penetrating visible light returning from the mucosal or subsurface tissue site; and

(c) determining a tissue hemoglobin oxygenation index based upon the returning visible light.

4. The method of claim 3 wherein said broadband illumination comprises a portion of the visible spectral band from 500 nm to 600 nm.

5. The method of claim 4 wherein said medical intervention is a vascular procedure directed toward the aorta, and said target tissue is the gastrointestinal mucosa.

6. The method of claim 3 wherein said medical intervention is a vascular procedure during which the local blood flow may change.

8. A visible wavelength optical spectroscopy oximeter system comprising:

(a) a broadband, low-thermal-transfer visible illumination source for illuminating a target region;

(b) an optical collector for collecting light scattered from said target region and for transmitting a collected signal to a spectroscopic monitor; and

(c). spectroscopic monitoring means for receiving and analyzing collected broadband visible light as a function of wavelength, said analysis substantially reliant upon received light with a wavelength below 600 nm so as to achieve a shallow, subsurface depth of penetration, and for determining an oxygen saturation index of hemoglobin in the target region based upon said monitored shallow penetrating visible light.

9. The oximeter of claim 8, wherein said saturation determination is substantially performed using collected light in the visible violet to green spectrum from 400 to 600 nm.

10. The oximeter of claim 8, wherein said saturation determination is substantially performed using collected light in the green to orange spectral band form 500 to 600 nm.