Method and apparatus of non-invasive measurement of human/animal blood glucose and other metabolites

• US 6,167,290 A
• Filed: 02/03/1999
• Issued: 12/26/2000
• Est. Priority Date: 02/03/1999
• Status: Expired due to Term

• Current Assignee: Biospex, Inc., Shu Zhang, Yang Wei
• Original Assignee: BaySpec, Inc. (II-VI Incorporated)
• Inventors: Yang, Wei, Zhang, Shu
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US09/244,330
• Time in Patent Office: 692 Days
• Field of Search: 600/316, 600/322, 600/334, 600/335, 600/365
• US Class Current: 600/322
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters

Abstract

A method and apparatus for non-invasively measuring animal/human blood glucose and other metabolites including an excitation laser source, a negative pressure based sampling port which interfaces to a human or other animal tissue sample in vivo, a Raman spectrometer, and data analysis and display devices. The device can be made in a compact size and may be portable, and it can be used in homes, offices or clinics. A negative atmospheric sampling port is made of a vacuum chamber that is connected with an electrically or manually driven vacuum pump which creates a negative air pressure inside the vacuum chamber. Under the negative air pressure, a substantial amount of blood is "sucked" into a small area of the human finger so that measurement of an enhanced Raman signal can be made.

Claims

1. A non-invasive blood inspection apparatus comprising:

means forming a chamber having an opening that is small compared to the size of a particular human/animal body part;

pumping means for reducing the fluid pressure within said chamber when said opening is blocked by a portion of the human/animal tissue forming the body part, the reduced pressure providing concentration of the blood within the portion of tissue blockingly engaging said opening;

means for projecting luminous energy through said chamber and onto said portion of said tissue and for collecting luminous energy reflected from the tissue;

shuttering means for selectively blocking said luminous energy when said opening is not engaged by said tissue;

pressure sensing means responsive to the pressure in said chamber and operative to close said shuttering means when the pressure within said chamber is above a predetermined level so as to prevent said luminous energy from passing through said opening unless said opening is blocked by said tissue; and

means for analyzing the collected luminous energy to determine a certain characteristic of the blood concentrated in said tissue.

2. A non-invasive blood inspection apparatus comprising optical non-invasive blood inspection apparatus as recited in claim 1 wherein said means for projecting luminous energy includes means for focusing the projected luminous energy onto said portion of tissue and for collecting and substantially collimating the collected luminous energy reflected from said tissue.

3. A non-invasive blood inspection apparatus as recited in claim 2 wherein said means for projecting includes a beam splitter means for separating particular wavelengths from said collected luminous energy and for reflecting the particular wavelengths into said means for analyzing.

4. A non-invasive blood inspection apparatus as recited in claim 3 wherein said means for analyzing comprises a Raman spectrometer.

5. A non-invasive blood inspection apparatus as recited in claim 4 wherein said means for projecting includes a laser light source.

6. A non-invasive blood inspection apparatus as recited in claim 1 wherein said means for projecting includes a laser light source.

7. A non-invasive blood inspection apparatus as recited in claim 1 wherein the means forming the chamber includes a reflective interior wall that is oriented to receive said luminous energy and is shaped such that luminous energy reflected therefrom is focused onto a spot within said opening.

8. A method of non-invasively analyzing the blood of a living human/animal comprising the steps of:

providing a chamber having an opening that is small compared to the size of a particular human/animal body part;

positioning said particular body part of a human/animal patient in engagement with said opening;

reducing the fluid pressure within said chamber when said opening is blocked by the portion of human/animal tissue forming the body part, the reduced pressure providing concentration of the blood within the portion of tissue blockingly engaging said opening;

projecting luminous energy through said chamber and onto said portion of tissue;

providing a shutter for selectively preventing said luminous energy from entering said chamber;

monitoring the pressure within said chamber and causing said shutter to open only in the event that the pressure falls below a predetermined level;

collecting luminous energy reflected from said portion of tissue; and

analyzing the collected luminous energy to determine certain characteristics of the blood concentrated in said tissue.

9. A method as recited in claim 8 wherein the step of collecting includes collecting only luminous energy that is limited to a predetermined range of wavelengths.

10. A method as recited in claim 8 wherein the step of projecting said luminous energy includes focusing the luminous energy onto a spot of said portion of said tissue that is substantially smaller than the area of said opening.

11. A method as recited in claim 8, wherein said certain characteristics include the blood glucose level of the patient.

12. A method as recited in claim 8, wherein the step of analyzing includes using a Raman spectrometer to analyze said collected luminous energy.

13. A method as recited in claim 8, wherein the step of collecting includes using a beam splitter to separate a particular wavelength from said collected luminous energy and to reflect the particular wavelength for analyzing purposes.

14. A method as recited in claim 13, wherein the step of analyzing includes using a Raman spectrometer to analyze the collected luminous energy.

15. A non-invasive blood inspection apparatus comprising:

means forming a chamber having an opening that is small compared to the size of a particular human/animal body part, said chamber including a reflective interior wall having a curved surface;

pumping means for reducing the fluid pressure within said chamber when said opening is blocked by a portion of the human/animal tissue forming the body part, the reduced pressure providing concentration of the blood within the portion of tissue blockingly engaging said opening;

means for projecting luminous energy into said chamber and onto said portion of said tissue, said reflective interior wall of said chamber being oriented to reflect and focus said luminous energy onto a spot within said opening;

means for collecting luminous energy reflected from the tissue via said reflective interior wall;

means for analyzing the collected luminous energy to determine a certain characteristic of the blood concentrated in said tissue.

16. A non-invasive blood inspection apparatus as recited in claim 15, wherein said means for analyzing comprises a Raman spectrometer.

17. A non-invasive blood inspection apparatus as recited in claim 15, wherein:

said means for projecting luminous energy into said chamber includes a center fiber; and

said means for collecting luminous energy includes a plurality of surrounding fibers surrounding said center fiber.

18. A non-invasive blood inspection apparatus as recited in claim 17 wherein said center fiber has a numeric aperture that is substantially larger than the numeric aperture of each of said surrounding fibers.

19. A non-invasive blood inspection apparatus as recited in claim 15, wherein said reflective interior wall of said chamber is ellipsoidally shaped.

20. A non-invasive blood inspection apparatus as recited in claim 15, wherein said means for projecting luminous energy provides projection of Raman scattering radiation, whereby said reflective interior wall of said chamber provides for high Raman scattering radiation collectivity.