System and method for tissue hydration estimation

• US 20080221411A1
• Filed: 03/09/2007
• Published: 09/11/2008
• Est. Priority Date: 03/09/2007
• Status: Abandoned Application

• Current Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Hausmann, Gilbert, Campbell, Shannon E., Ferro, Allison
• Application Number:
  US11/716,443
• Publication Number:
  US 20080221411A1
• Time in Patent Office: Days
• US Class Current: 600/310
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/445 Evaluating skin irritation or skin trauma, e.g. rash, eczema, wound, bed sore
• CPC Class Codes: A61B 5/4869 Determining body composition
• CPC Class Codes: A61B 5/4875 Hydration status, fluid retention of the body
• CPC Class Codes: G01J 2003/1213 Filters in general, e.g. dichroic, band
• CPC Class Codes: G01J 2003/2806 Array and filter array
• CPC Class Codes: G01N 21/3554 for determining moisture content
• CPC Class Codes: G01N 21/359 using near infrared light

Abstract

A system and method are provided for determining tissue hydration. The method includes transmitting electromagnetic radiation at tissue and detecting the absorption spectrum of the tissue using a spectrum analyzer located in a sensor. Further, the method includes providing a signal correlative to the absorption spectrum from the spectrum analyzer to a monitor and processing the signal to determine an amount of water content in the tissue.

Claims

1. A method for determining tissue hydration comprising:

transmitting electromagnetic radiation at tissue;

detecting the absorption spectrum of the tissue using a spectrum analyzer located in a sensor;

providing a signal correlative to the absorption spectrum from the spectrum analyzer to a monitor; and

processing the signal to determine an amount of water content in the tissue.

2. The method of claim 1 wherein transmitting electromagnetic radiation comprises transmitting a plurality of discrete wavelengths within the near-infrared (NIR) spectrum.

3. The method of claim 2, wherein transmitting the plurality of discrete wavelengths within the NIR spectrum comprises using three LEDs operating at different wavelengths between 1100 nm and 1400 nm.

4. The method of claim 1, wherein transmitting the electromagnetic radiation comprises using a broadband light source.

5. The method of claim 4, wherein the broadband light source emits white light.

6. The method of claim 1 wherein interpreting the spectrum comprises analyzing the distribution of spectral power to determine a ratio of water to other constituents.

7. The method of claim 1 comprising displaying the water content on a display.

8. The method of claim 7 wherein displaying the water content comprises displaying a ratio of water-to-other constituents as a percentage.

9. The method of claim 1 wherein the spectrum analyzer comprises a solid state spectrometer.

10. The method of claim 9 wherein the solid state spectrometer comprises filters to control the bandwidth of electromagnetic radiation that impinges on a detector array.

11. The method of claim 10 wherein the filters allow a 10 nm bandwidth of electromagnetic radiation impinge on the detector array.

12. The method of claim 1 wherein the spectrum analyzer comprises a micro-electro-mechanical system.

13. The method of claim 12 wherein the micro-electro-mechanical system comprises dielectric stack layers used to filter electromagnetic radiation.

14. A system for determining tissue constituents comprising:

a sensor comprising;

a source of electromagnetic radiation configured to transmit electromagnetic radiation at tissue;

a spectrum analyzer configured to detect the transmitted electromagnetic radiation and determine the spectral content of the detected electromagnetic radiation; and

a monitor communicatively coupled to the sensor and configured to receive and process the spectral content to determine the amount of water constituent present in the tissue.

15. The system of claim 14, wherein the spectrum analyzer comprising a solid state spectrum analyzer.

16. The system of claim 14 wherein the spectrum analyzer comprising a micro-electro-mechanical system (MEMS) device comprising a Fabry-Perot filter.

17. The system of claim 14 wherein the source of electromagnetic radiation is continuous spectrum light source.

18. The system of claim 14 wherein the continuous spectrum light source is a white light source.

19. The system of claim 14 wherein the source of electromagnetic radiation comprises a plurality of narrow band light sources.

20. The system of claim 19 wherein the plurality of narrow band light sources comprises light emitting diodes (LEDs) operating in the NIR band of the electromagnetic spectrum.