Blood sugar level measuring apparatus

• US 20060063990A1
• Filed: 11/22/2004
• Published: 03/23/2006
• Est. Priority Date: 08/25/2004
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Cho, Ok-Kyung, Ouchi, Katsumi, Mitsumaki, Hiroshi, Kim, Yoon-Ok
• Application Number:
  US10/992,689
• Publication Number:
  US 20060063990A1
• 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

Abstract

An apparatus for accurately determining the blood hemoglobin concentration without taking a blood sample. The apparatus comprises an ambient temperature measuring portion for measuring ambient temperature, a radiation heat detector for measuring radiation heat from a body surface, light sources for irradiating the body surface with light of the wavelengths of at least 810 nm and 950 nm, photodetectors for detecting reflected light from the body surface, a converting portion in which measurement values relating to the blood hemoglobin concentration measured using a blood sample that is separately collected, said converting portion converting the stored measurement value, the individual outputs of the ambient temperature measuring portion, the radiation heat detector, and the photodetector, into a plurality of parameters, and a processing portion in which relationships between the parameters and blood sugar levels are stored, said calculating portion calculating a blood sugar level by applying the parameters to the stored relationships.

Claims

1. A blood sugar level measuring apparatus comprising:

a heat amount measuring portion for measuring a temperature deriving from a body surface in order to obtain information used for the calculation of the amount of heat transfer due to convection and the amount of heat transfer due to radiation, which are related to the dissipation of heat from said body surface;

an optical measuring portion for irradiating said body surface with light in order to obtain measurement values related to the blood hemoglobin concentration and the hemoglobin oxygen saturation inside tissue;

a memory portion for storing a measurement value relating to the blood hemoglobin concentration measured using a blood sample that is separately collected, and for storing relationships between parameters corresponding to said temperature, said blood hemoglobin concentration and said hemoglobin oxygen saturation inside tissue, the volume of blood flow inside tissue, and blood sugar levels;

a calculation portion for converting a plurality of measurement values inputted from said heat amount measuring portion and said optical measuring portion, into said parameters individually, and for calculating a blood sugar level by applying said parameters to said relationships stored in said memory portion; and

a display portion for displaying the result of calculation in said calculation portion, wherein

the parameter corresponding to said blood flow volume inside tissue is generated on the basis of a ratio between the blood hemoglobin concentration inside tissue and the blood hemoglobin concentration measured using said blood sample.

2. The blood sugar level measuring apparatus according to claim 1, wherein said optical measuring portion comprises:

a light source for producing light of at least two different wavelengths;

an optical system for irradiating said body surface with light emitted by said light source; and

a photodetector for detecting reflected light from said body surface.

3. The blood sugar level measuring apparatus according to claim 2, wherein said optical measuring portion comprises:

a light source for emitting light of the wavelength of substantially 810 nm; and

a light source for emitting light of the wavelength of substantially 950 nm.

4. The blood sugar level measuring apparatus according to claim 1, wherein said heat amount measuring portion comprises:

an ambient temperature detector for measuring ambient temperature; and

a radiation temperature detector for measuring radiation heat from said body surface.

5. A blood sugar level measuring apparatus comprising:

an ambient temperature measuring portion for measuring ambient temperature;

a radiation heat detector for measuring radiation heat from a body surface;

a light source for irradiating said body surface with at least light of a first wavelength and light of a second wavelength;

a photodetector for detecting reflected light that is produced as said light from said light source is reflected by said body surface;

a memory portion for storing a measurement value relating to the blood hemoglobin concentration that is measured using a blood sample that is separately collected;

a calculating portion including a converting portion for converting said stored measurement value and the individual outputs of said ambient temperature measuring portion, said radiation heat detector, and said photodetector into a plurality of parameters, and a processing portion in which relationships between said parameters and blood sugar levels are stored, said processing portion calculating a blood sugar level by applying said parameters to said relationships; and

a display portion for displaying a result outputted from said calculating portion.

6. The blood sugar level measuring apparatus according to claim 5, wherein said stored measurement value is associated with the output of said photodetector when converted into said parameter.

7. The blood sugar level measuring apparatus according to claim 5, wherein said stored measurement value is converted into said parameter based on its ratio to the output of said photodetector.

8. The blood sugar level measuring apparatus according to claim 5, further comprising an infrared lens between an open end through which said light source emits said light of said first wavelength and said second wavelength and said radiation heat detector.

9. The blood sugar level measuring apparatus according to claim 7, further comprising an infrared light transmitting window between said infrared lens and said radiation heat detector.

10. The blood sugar level measuring apparatus according to claim 5, wherein said ambient temperature measuring portion comprises a temperature-measuring resistor disposed near said radiation heat detector.

11. The blood sugar level measuring apparatus according to claim 5, wherein said first wavelength and said second wavelength are substantially 810 nm and substantially 950 nm, respectively.