NON-INVASIVE, CONTINUOUS, REAL-TIME SYSTEM FOR DETERMINING TISSUE HYPOPERFUSION

• US 20130317329A1
• Filed: 02/03/2012
• Published: 11/28/2013
• Est. Priority Date: 02/03/2011
• Status: Abandoned Application

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Barodka, Viachaslau Mikalayevich, Berkowitz, Daniel
• Application Number:
  US13/982,664
• Publication Number:
  US 20130317329A1
• Time in Patent Office: Days
• US Class Current: 600/322
• 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 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: G01N 2021/3144 for oxymetry
• CPC Class Codes: G01N 2021/3148 using three or more wavelengths
• CPC Class Codes: G01N 21/31 Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry G01N21/72 takes precedence

Abstract

A non-invasive, continuous, real-time detection system for determining an amount of tissue hypoperfusion in a patient includes an illumination system adapted to illuminate a section of tissue of a patient with light comprising at least five wavelength components, a detection system arranged to detect light from the illumination system after the light has passed through the section of tissue, and a signal processing system adapted to communicate with the detection system. The signal processing system is configured to calculate a relative amount of each of five forms of hemoglobin compared to substantially total hemoglobin, the five forms of hemoglobin being oxy-hemoglobin, deoxy-hemoglobin, met-hemoglobin, carboxy-hemoglobin, and sulf-hemoglobin. The signal processing system outputs information concerning detected sulf-hemoglobin for determining the amount of tissue hypoperfusion, and the illumination system and the detection system are adapted to be at least one of stuck on, clamped on, or attached to an external region of the patient'"'"'s body.

Claims

1. A non-invasive, continuous, real-time detection system for determining an amount of tissue hypoperfusion in a patient, comprising:

an illumination system adapted to illuminate a section of tissue of a patient with light comprising at least five wavelength components;

a detection system arranged to detect light from said illumination system after said light has passed through said section of tissue; and

a signal processing system adapted to communicate with said detection system,

wherein said signal processing system is configured to calculate a relative amount of each of five forms of hemoglobin compared to substantially total hemoglobin, said five forms of hemoglobin being oxy-hemoglobin, deoxy-hemoglobin, met-hemoglobin, carboxy-hemoglobin, and sulf-hemoglobin,

wherein said signal processing system outputs information concerning detected sulf-hemoglobin for determining said amount of tissue hypoperfusion, and

wherein said illumination system and said detection system are adapted to be at least one of stuck on, clamped on, or attached to an external region of said patient'"'"'s body.

2. A non-invasive, continuous, real-time detection system for determining an amount of tissue hypoperfusion in a patient according to claim 1, wherein one of said five wavelength components is about 621 nm.

3. A non-invasive, continuous, real-time detection system for determining an amount of tissue hypoperfusion in a patient according to claim 1, wherein each of said five wavelength components corresponds to substantially a peak absorption wavelength of an absorption curve for a corresponding one of each of said five forms of hemoglobin.

4. A non-invasive, continuous, real-time detection system for determining an amount of tissue hypoperfusion in a patient according to claim 3, wherein one of said five wavelength components is about 621 nm.

5. A non-invasive, continuous, real-time detection system for determining an amount of tissue hypoperfusion in a patient according to claim 1, wherein said substantially total hemoglobin is determined to be a sum of amounts of all of said five forms of hemoglobin detected.

6. A non-invasive, continuous, real-time detection system for determining an amount of tissue hypoperfusion in a patient according to claim 1, further comprising a display system configured to communicate with said signal processor to display said information concerning detected sulf-hemoglobin for determining said amount of tissue hypoperfusion.

7. A non-invasive, continuous, real-time detection system for determining an amount of tissue hypoperfusion in a patient according to claim 6, wherein said signal processor is configured to output said relative amount of sulf-hemoglobin to be displayed by said display system.

8. A non-invasive, continuous, real-time detection system for determining an amount of tissue hypoperfusion in a patient according to claim 7, wherein said signal processor is further configured to compare said relative amount of sulf-hemoglobin to a threshold and to output an alarm signal to said display system when said threshold is exceeded.

9. A non-invasive, continuous, real-time detection system for determining an amount of tissue hypoperfusion in a patient according to claim 8, wherein said display system displays at least one a visible or an audible alarm in response to said alarm signal output by said signal processor when said when said threshold is exceeded.

10. A non-invasive, continuous, real-time detection system for determining an amount of tissue hypoperfusion in a patient according to claim 6, further comprising a data storage unit configured to communicate with said signal processor, wherein said signal processor is configured to store a plurality of calculated relative amounts of sulf-hemoglobin over a period of time to form a trend of relative amounts of sulf-hemoglobin as a function of time, and

wherein said display system is configured to display said trend of relative amounts of sulf-hemoglobin over said period of time.

11. A non-invasive, continuous, real-time detection system for determining an amount of tissue hypoperfusion in a patient according to claim 10, wherein said signal processor is configured to store a plurality of calculated relative amounts of met-hemoglobin over a period of time to form a trend of relative amounts of met-hemoglobin as a function of time, and

wherein said signal processor is further configured to compare said trend of relative amounts of sulf-hemoglobin to said trend of relative amounts of met-hemoglobin to distinguish between hypoperfusion due to sepsis shock and hypoperfusion due to cardiogenic shock.

12. A non-invasive, continuous, real-time method for determining an amount of tissue hypoperfusion in a patient, comprising:

illuminating a section of tissue of a patient with light comprising at least five wavelength components;

detecting light from said illuminating after said light has passed through said section of tissue;

calculating a relative amount of each of five forms of hemoglobin compared to substantially total hemoglobin with a signal processing system, said five forms of hemoglobin being oxy-hemoglobin, deoxy-hemoglobin, met-hemoglobin, carboxy-hemoglobin, and sulf-hemoglobin; and

determining said amount of tissue hypoperfusion based on said relative amount detected sulf-hemoglobin.

13. A non-invasive, continuous, real-time method for determining an amount of tissue hypoperfusion in a patient according to claim 12, further comprising comparing said relative amount of sulf-hemoglobin to a threshold and signaling an alarm when said threshold is exceeded.

14. A non-invasive, continuous, real-time method for determining an amount of tissue hypoperfusion in a patient according to claim 12, further comprising comparing a trend of relative amounts of sulf-hemoglobin to a trend of relative amounts of met-hemoglobin over time both detect hypoperfusion and to distinguish between hypoperfusion due to sepsis shock and hypoperfusion due to cardiogenic shock.