Non-invasive blood constituent measuring instrument and measuring method

• US 20080027297A1
• Filed: 06/26/2007
• Published: 01/31/2008
• Est. Priority Date: 03/25/2002
• Status: Active Grant

• Current Assignee: Yu.Sys. Corporation
• Original Assignee: TYT Institute of Technology Corporation
• Inventors: Yamakoshi, Ken-ichi
• Granted Patent: US 8,275,433 B2
• Time in Patent Office: Days
• US Class Current: 600/316
• 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
• CPC Class Codes: G01N 21/359 using near infrared light
• CPC Class Codes: G01N 2201/1228 Reading time being controlled, e.g. by microprocessor
• CPC Class Codes: G01N 2201/1232 Log representation, e.g. for low transmittance
• CPC Class Codes: G01N 2201/129 Using chemometrical methods
• CPC Class Codes: G01N 33/491 by separating the blood components G01N15/05 takes precedence

Abstract

A non-invasive blood constituents measuring instrument measures blood constituent values including blood glucose concentration in a living body non-invasively. The instrument is composed of a light source 11 to irradiate a light containing plural wavelengths to a living body 13, a light receiver 14 to detect the light transmitted through a living body or reflected and scattered thereon, a spectrum analyzer 15 to analyze the light transmitted through the living body or reflected thereon at different times, a subtraction processor 18 to generate spectrum subtraction from the spectrum of the light at the different times measured by the spectrum analyzer 15, and a blood glucose concentration predictor 21 into which the output data of the subtraction processor 18 are input and which outputs a blood constituent value.

Claims

1. A non-invasive blood constituents measuring instrument comprising:

a light source for irradiating light including plural waveforms to a living body whose blood constituents are unknown;

a light receiver to detect light transmitted through the living body or reflecting thereon;

a spectrum analyzer to which the output signal of the light receiver is supplied and which analyzes spectrum of the light transmitted through the living body or reflected therefrom at different times having a shorter time intervals than a cycle time of the arterial waveform cycle;

a spectrum subtraction generator to generate spectrum subtraction from the spectrum of the light measured by the spectrum analyzer at the different times; and

a blood constituents predictor into which the output data of the spectrum subtraction generator is input and which outputs the blood constituents;

wherein the blood constituents predictor compares the spectrum subtraction of the unknown constituents blood with a plurality of sample spectrum subtractions which are obtained from a living body whose blood constituents are known in a similar manner as obtained from a living body whose blood constituents are unknown and predicts the blood constituents of the unknown constituents blood.

2. A non-invasive blood constituents measuring instrument claimed in claim 1, wherein the blood constituents predictor is provided with a multi-regression analyzing model using the plurality of the sample spectrum subtractions as an explanatory variable and blood constituent values as an objective variable, wherein the spectrum subtraction data obtained from the living body having known blood constituents are input into the multi-regression analyzing model as an explanatory variable, the objective variable is computed from the multi-regression analyzing model and output as a blood constituent value.

3. A non-invasive blood constituents measuring instrument claimed in claim 2, wherein the multi-regression analyzing model is a regression analysis model using the PLS or PCR method.

4. A non-invasive blood constituent measuring instrument claimed in claim 3, wherein blood constituents of the living bodies corresponding to the sample spectrum subtractions are arranged at a specified interval within the range of concentration including the physiological concentration range.

5. A non-invasive blood constituent measuring instrument claimed in claim 4, wherein the light including the plural wavelengths is the light in the near infrared range.

6. A non-invasive blood constituent measuring instrument claimed in claim 5, wherein the light includes plural wavelengths in the wavelength band of 800-2400 nm arranged at an interval of 3 nm.

7. A non-invasive blood constituent measuring instrument claimed in claim 6, wherein the light including the plural wavelengths is generated by separating the light from the light source by the active spectroscope.

8. A non-invasive blood constituent measuring instrument claimed in claim 7, wherein the active spectroscope separates the light in the near infrared range at an interval of 40-50 ms period of time.

9. A non-invasive blood glucose concentration measuring instrument comprising:

a light source to irradiate a light containing plural wavelengths to a living body whose blood glucose concentration is unknown;

a light receiver to detect the light transmitted through a living body or reflected therefrom;

a spectrum analyzer to which the output signal of the light receiver is supplied and which analyzes spectrum of the light transmitted through the living body or reflected therefrom at different times having a shorter time intervals than a cycle time of the arterial waveform;

a spectrum subtraction generator to generate spectrum subtraction from the spectrum of the light measured by the spectrum analyzer at the different times; and

a blood glucose concentration predictor into which the output data of the spectrum subtraction generator is input and which outputs the blood glucose concentration;

wherein the blood glucose concentration predictor compares the spectrum subtraction of the unknown glucose concentration with a plurality of sample spectrum subtractions which are obtained from a living body whose blood glucose concentration is known in a similar manner as obtained from the living body whose blood glucose concentration is unknown and predicts the blood glucose concentration of the unknown constituents blood.

10. A non-invasive blood glucose concentration measuring instrument claimed in claim 9, wherein the blood glucose concentration predictor is provided with a multi-regression analyzing model using the plurality of the sample spectrum subtractions as an explanatory variable and blood glucose values as an objective variable, wherein the spectrum subtraction data obtained from living bodies having unknown blood constituents are input into the multi-regression analyzing model as an explanatory variable, the objective variable is computed from the multi-regression analyzing model and output as a blood constituent value.

11. A non-invasive blood glucose concentration measuring instrument claimed in claim 10, wherein the multi-regression analyzing model is a regression analysis model using the PLS or PCR method.

12. A non-invasive blood glucose concentration measuring instrument claimed in claim 11, wherein blood glucose concentrations according to the sample spectrum subtractions are arranged at a specified interval within the range of concentration including the physiological concentration range.

13. A non-invasive blood glucose concentration measuring instrument claimed in claim 12, wherein the light including the plural wavelengths is the light in the near infrared range.

14. A non-invasive blood glucose concentration measuring instrument claimed in claim 12, wherein the light includes plural wavelengths in the wavelength band of 800-2400 nm arranged at an interval of 3 nm.

15. A non-invasive blood glucose concentration measuring instrument claimed in claim 14, wherein the light including the plural wavelengths is generated by separating the light from the light source by the active spectroscope.

16. A non-invasive blood glucose concentration measuring instrument claimed in claim 15, wherein the active spectroscope separates the light in the near infrared range at the interval of 40-50 ms period of time.

17. A non-invasive blood glucose concentration measuring instrument claimed in claim 12, wherein the plural whole blood samples include protein containing albumin.

18. A non-invasive blood glucose concentration measuring instrument claimed in claim 17, wherein the concentration of the albumin is 3.0-6.0 g/dl.

19. A non-invasive blood glucose concentration measuring instrument claimed in claim 18, wherein the plural whole blood samples contain blood having different hematocrit values.

20. A method for non-invasively measuring blood constituents comprising the steps of:

irradiating a light containing plural wavelengths to a living body whose blood constituents are unknown;

detecting light transmitted through or reflected from the living body and converting it into an electric signal;

analyzing spectrum of the light transmitted through the living body or reflected therefrom at different times having a shorter time intervals than a cycle time of the arterial waveform cycle using the converted electric signal;

generating spectrum subtraction from the spectrum of the light at the different times; and

predicting corresponding blood constituents from the spectrum subtraction;

wherein the spectrum subtraction of the unknown constituents blood is compared with a plurality of sample spectrum subtractions which are obtained from a living body whose blood constituents are known in a similar manner as obtained from the living body whose blood constituents are unknown and thereby the blood constituents of the unknown constituents blood is predicted.

21. A method for non-invasively measuring blood constituents claimed in claim 20, wherein the step of predicting the blood constituents further comprises;

preparing a multi-regression analyzing model, to which spectrum data of plural sample spectrum subtractions, the blood constituents of which are known are input as explanatory variables and outputs blood constituents as objective variables, inputting the spectrum subtraction data obtained from the living body the blood constituents of which is not known as explanatory variables, and outputting the blood constituents as the objective variables.

22. A method for non-invasively measuring blood constituents claimed in claim 21, wherein the multi-regression analyzing model is constructed using the PLS or PCR method.

23. A method for non-invasively measuring blood glucose concentration comprising the steps of:

irradiating a light containing plural wavelengths to a living body whose blood glucose concentration is unknown;

detecting light transmitted through or reflected from the living body and converting it into an electric signal;

analyzing spectrum of the light transmitted through the living body or reflected therefrom at different times having a shorter time intervals than a cycle time of the arterial waveform cycle using the converted electric signal;

generating spectrum subtraction from the spectrum of the light at the different times; and

predicting corresponding blood glucose concentration from the spectrum subtraction;

wherein the step of blood predicting the glucose concentration further comprises;

comparing the spectrum subtraction of the unknown glucose concentration with a plurality of sample spectrum subtractions which are obtained from a living body whose blood glucose concentration is known in a similar manner as obtained from the living body whose blood glucose concentration is unknown and predicting the blood glucose concentration of the unknown constituents blood.

24. A method for non-invasively measuring blood glucose concentrations claimed in claim 23, wherein the step of predicting the blood glucose concentration further comprises;

preparing a multi-regression analyzing model, to which spectrum data of plural sample spectrum subtractions, the blood constituents of which are known are input as explanatory variables and outputs blood constituents as objective variables, inputting the spectrum subtraction data obtained from the living body the blood constituents of which is not known as explanatory variables, and outputting the blood constituents as the objective variables.

25. A method for non-invasively measuring blood glucose concentrations claimed in claim 24, wherein the multi-regression analyzing model is constructed using the PLS or PCR method.