Portable apparatus for noninvasively measuring blood glucose level and operating method thereof

Patent metadata

Field	Value
Publication number	US-10555693-B2
Application number	US-201715430521-A
Country	US
Kind code	B2
Filing date	Feb 12, 2017
Priority date	Feb 12, 2017
Publication date	Feb 11, 2020
Grant date	Feb 11, 2020

Abstract

Disclosed in an embodiment is an operating method of portable apparatus for noninvasively measuring blood glucose levels. The method includes: (a) measuring a first signal value according to ambient environmental light when an LED for measuring signals which emits light with wavelengths to be absorbed into or scattered by glucose is switched off; (b) measuring a second signal value according to light which is scattered by or transmitted through subject tissue and enters a photodetecting unit when the LED for measuring signals is switched on; (c) calculating a glucose concentration measurement of a subject by using the first signal value and the second signal value; and (d) adjusting the quantity of the light radiated from the LED for measuring signals by feeding the difference between the glucose concentration measurement and a pre-established first reference value back to the driving current for the LED for measuring signals.

First claim

What is claimed is:

1. An operating method of a portable apparatus for noninvasively measuring blood glucose levels, comprising:
(a) measuring a first signal value according to ambient environmental light and temperature by using a photodiode detector when an LED for measuring signals which emits light with a wavelength range to be absorbed into or scattered by glucose is switched off;
(b) measuring a second signal value according to light which is scattered by or transmitted through a subject tissue and enters the photodiode detector when the LED for measuring signals with the wavelength range is switched on;
(c) calculating a glucose concentration measurement of a subject by using the first signal value and the second signal value; and
(d) adjusting an intensity of the light radiated from the LED for measuring signals by feeding a difference between the glucose concentration measurement and a pre-established first reference value back to a driving current for the LED for measuring signals.

2. The operating method of claim 1 ,
(e) the steps from (b) through (d) are repeatedly performed by using the LED for measuring signals driven with the driving current until the glucose concentration measurement becomes equal to the first reference value.

3. The operating method of claim 1 , wherein, in the step (d), the driving current for the LED for measuring signals is reduced when the result of subtracting the first reference value from the glucose concentration measurement is positive while the driving current for the LED for measuring signals is increased when the result of subtracting the first reference value from the glucose concentration measurement is negative.

4. The operating method of claim 1 , wherein the step (c) comprises:
(c-1) calculating the glucose concentration measurement by correcting the second signal value by subtracting the first signal value from the second signal value; and
(c-2) producing blood glucose measuring results of the subject by matching the glucose concentration measurement with a blood glucose level table established to be corresponding to each glucose concentration.

5. The operating method of claim 1 , the method further comprises:
(f) measuring a third signal value according to light which is scattered by or transmitted through the subject tissue and enters the photodiode detector when a reference LED which emits light with a second wavelength range which are neither absorbed in nor scattered by glucose is switched on;
(g) calculating a compensating value to compensate for a change in the amount of scattering or transmission according to skin characteristics and body temperature of the subject based on the difference between a reference measurement produced by subtracting the first signal value from the third signal value and a second reference value pre-established with reference to a standard subject;
(h) adjusting the driving current for the LED for measuring signals based on the compensating value,
prior to the step (b), and

wherein the wavelength range is 800 to 1000 nm and the second wavelength range is 600 to 800 nm.

6. The operating method of claim 5 , wherein the step (b) comprises:
(b-1) measuring the second signal value when the LED for measuring signals driven with the driving current is switched on; and
(b-2) measuring again the first signal value when the LED for measuring signals is switched off.

7. The operating method of claim 5 , wherein (g) determines the compensating value by matching the difference between the reference measurement and the second reference value with a table with regard to glucose detection changes according to previously stored skin colors.

8. The operating method of claim 5 , wherein (h) reduces the driving current for the LED for measuring signals when the compensating value is positive, and increases the driving current for the LED for measuring signals when the compensating value is negative.

9. The operating method of claim 1 , the method further comprises:
(i) removing noise out of and correcting the first signal value and the second signal value based on an autofocusing algorithm.

10. A portable apparatus for noninvasively measuring blood glucose levels, comprising:
an LED for measuring signals which emits light with a wavelength range absorbed into or scattered by glucose;
a photodiode detector which includes at least one light receiving element and converts the light received by the at least one light receiving element to an electrical signal; and
a processor which is connected to the photodiode detector to collect a first signal value detected according to ambient environmental light and temperature when the LED for measuring signals is switched off and a second signal value detected according to light which is scattered by or transmitted through a subject tissue and enters the photodiode detector when the LED for measuring signals is switched on, calculate a glucose concentration measurement of a subject by using the first signal value and the second signal value and adjust an intensity of the light radiated from the LED for measuring signals by feeding the difference between the glucose concentration measurement and a pre-established first reference value back to a driving current for the LED for measuring signals.

11. The portable apparatus for noninvasively measuring blood glucose levels of claim 10 , wherein the processor repeatedly produces the glucose concentration measurement by using the LED for measuring signals driven with the driving current until the glucose concentration measurement becomes equal to the first reference value.

12. The portable apparatus for noninvasively measuring blood glucose levels of claim 10 , wherein the processor reduces the driving current for the LED for measuring signals when the result of subtracting the first reference value from the glucose concentration measurement is positive while increases the driving current for the LED for measuring signals when the result of subtracting the first reference value from the glucose concentration measurement is negative.

13. The portable apparatus for noninvasively measuring blood glucose levels of claim 10 , wherein the processor produces the glucose concentration measurement by correcting the second signal value by subtracting the first signal value from the second signal value and produces the blood glucose measuring results of the subject by matching the glucose concentration measurement with a blood glucose level table established to be corresponding to each glucose concentration.

14. The portable apparatus for noninvasively measuring blood glucose levels of claim 10 , the apparatus further comprises:
a reference LED which emits light with a second wavelength range which are neither absorbed in nor scattered by glucose, wherein the processor obtains a third signal value detected according to light which is scattered by or transmitted through the subject tissue and enters the photodiode detector by switching the reference LED on when the LED for measuring signals is switched off, calculates a compensating value to compensate for a change in the amount of scattering or transmission according to skin characteristics and body temperature of the subject based on a difference between a reference measurement produced by subtracting the first signal value from the third signal value and a second reference value pre-established with reference to a standard subject and adjusts the driving current for the LED for measuring signals based on the compensating value, and
wherein the wavelength range is 800 to 1000 nm and the second wavelength range 600 to 800 nm.

Assignees

• Kim Hoon

Inventors

• Kim Hoon

Classifications

• A61B5/1032

  Determining colour of tissue for diagnostic purposes · CPC title

• A61B5/01

  Measuring temperature of body parts {; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue} (clinical contact thermometers G01K13/20) · CPC title

• A61B5/14532

  for measuring glucose, e.g. by tissue impedance measurement · CPC title

• A61B2562/0233

  Special features of optical sensors or probes classified in A61B5/00 · CPC title

• A61B5/681

  Wristwatch-type devices · CPC title