Non-invasive blood monitor

• US 20040138539A1
• Filed: 01/07/2004
• Published: 07/15/2004
• Est. Priority Date: 01/07/2003
• Status: Abandoned Application

• Current Assignee: Intelligent Photonics Control Corp.
• Original Assignee: Intelligent Photonics Control Corp.
• Inventors: Ribaric, Zeljko, Jay, Paul R.
• Application Number:
  US10/752,012
• Publication Number:
  US 20040138539A1
• Time in Patent Office: Days
• US Class Current: 600/322
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters

Abstract

A blood species concentration tester, and corresponding method, are disclosed herein. The tester employs the measurement of the characteristics of at least one wavelength of light returned from the eye of a patient to determine the concentration of a species, such as glucose, in a blood stream. The correlation of the characteristics of the at least one wavelength with each other, is utilised to derive an accurate measure that can provide a simpler and more accurate test of blood sugar levels, along with other species concentration levels.

Claims

1. A blood species tester, for determining the concentration of a species flowing in a blood vessel of a subject, the tester comprising:

a light source for transmitting a light pulse, having at least one known characteristic, to an eye of the subject;

a light detector for receiving and characterizing a modified light pulse; and

a controller, for determining a transfer function relating at least one of the at least one known characteristics to at least one characteristic of the modified pulse, and for mapping the determined transfer function to a species concentration in accordance with a predetermined mapping function.

2. The tester of claim 1, wherein the species is selected from a list including glucose, alcohol, and tetrahydrocannabinol.

3. The tester of claim 1, wherein the at least one known characteristic is selected from a list including wavelength and intensity.

4. The tester of claim 1, wherein the at least one characteristic of the modified pulse is selected from a list including intensity, polarisation, and fluorescence.

5. The tester of claim 1 wherein the light source includes means for transmitting a pulse having a plurality of known characteristics.

6. The tester of claim 5, wherein the means for transmitting a plurality of known characteristics includes a plurality of light sources, each of the plurality for transmitting a light pulse, having at least one known characteristic.

7. The tester of claim 5, wherein the controller determines transfer functions relating each of the known characteristics to measured characteristics in the modified pulse.

8. The tester of claim 1, wherein the controller includes a memory means for storing historical species concentration information.

9. The tester of claim 8, wherein the controller includes subject identification means for obtaining subject identification information from at least one characteristic in the modified light pulse, for storing identification information with associated historical species concentration information in the memory means, and for differentiating species concentration information stored in the memory on the basis of the associated identification information.

10. The tester of claim I including a calibration mechanism for determining the mapping function by correlating a plurality of determined transfer functions to species concentrations obtained using an external species concentration tester.

11. A method of determining a species concentration in a subject'"'"'s blood vessels, the method comprising:

generating and transmitting a light pulse having at least one known characteristic;

receiving and characterizing a modified, returned light pulse; and

determining the species concentration in accordance with a mapping function and a transfer function relating the at least one known characteristic with a corresponding characteristic in the modified, returned light pulse.

12. The method of claim 11 including the step of calibrating the mapping function to map the transfer function to known species concentrations in advance of the step of determining the species concentration.

13. The method of claim 11, wherein the step of generating and transmitting includes transmitting the light pulse into an eye of the subject.

14. The method of claim 13, wherein the step of receiving and characterizing includes receiving the modified returned light pulse from the ocular vasculature.

15. The method of claim 11, wherein the step of generating and transmitting includes transmitting a light pulse having a plurality of known characteristics.

16. The method of claim 11, wherein the step of generating and transmitting includes transmitting a series of light pulses.

17. The method of claim 16, wherein the step of transmitting a series of light pulses includes generating and transmitting a series of light pulses, each of the series of light pulses having at least one known characteristic, at least two of the series of light pulses having different known characteristics.

18. The method of claim 16, wherein the step of receiving and characterizing, includes receiving and characterizing a plurality of modified returned light pulses, and wherein the step of determining the species concentration includes determining a transfer function relating the known characteristic of each light pulse to a corresponding characteristic in a corresponding returned modified pulse.

19. The method of claim 11, wherein the step of determining the species concentration includes determining the transfer function in accordance with external environmental factors.

20. The method of claim 19, wherein the external environmental factors include ambient temperature.

21. The method of claim 11 further including the step of recording the determined species concentration in an archive of historical species concentrations.