Blood sugar level measuring apparatus

• US 7,120,478 B2
• Filed: 08/28/2003
• Issued: 10/10/2006
• Est. Priority Date: 07/11/2003
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Cho, Ok-Kyung, Kim, Yoon-Ok
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US10/649,689
• Publication Number:
  US 20050010094A1
• Time in Patent Office: 1,139 Days
• Field of Search: 600/310, 600/316, 600/322, 600/323, 600/326, 600/365, 600/549
• US Class Current: 600/316
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/015 By temperature mapping of body part
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• 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
• CPC Class Codes: G01K 17/00 Measuring quantity of heat measuring temperature by calorimetry G01K3/00 - G01K11/00; specially adapted for measuring thermal properties of materials, e.g. specific heat, heat of combustion G01N

Abstract

Blood sugar levels are non-invasively measured based on temperature measurements. An insulation structure is employed in a temperature measurement part for measuring heat amount and non-invasively obtained blood sugar level measurements are corrected by blood oxygen saturation and the volume of blood flow so that the measurement data can be stabilized and the measurement accuracy can be enhanced.

Claims

1. A blood sugar level measuring apparatus comprising:

a heat amount measuring unit for measuring a plurality of temperatures derived from the body surface in order to obtain information used for calculating the amount of convective heat transfer and the amount of radiation heat transfer concerning the dissipation of heat from the body surface;

an oxygen volume measuring unit for obtaining information concerning the volume of blood oxygen;

a storage unit for storing the relationships between the individual parameters corresponding to the multiple temperatures and blood oxygen volume and blood sugar levels;

a computing unit for converting the measurement values provided by the heat amount measuring unit and the oxygen volume measuring unit into parameters, and computing a blood sugar level by applying the parameters to the relationships stored in the storage unit; and

a display unit for displaying the blood sugar level computed by the computing unit,

wherein the oxygen volume measuring unit comprises a blood flow volume measuring unit for obtaining information concerning the volume of blood flow and a heat transfer prevention means for preventing heat transfer to the blood flow volume measuring unit from the vicinity thereof, wherein the blood flow volume measuring unit comprises;

a body-surface contact unit;

an adjacent temperature detector disposed adjacent the body-surface contact unit;

an indirect temperature detector for detecting the temperature at a position distanced away from the body-surface contact unit; and

a heat-conducting member connecting the body-surface contact unit and the indirect temperature detector, wherein

the heat transfer prevention means prevents heat transfer to the heat-conducting member.

2. The blood sugar level measuring apparatus according to claim 1, further comprising at least one supporting column member for installing the blood flow volume measuring unit,

wherein the heat transfer prevention means is a heat insulator disposed between the heat-conducting member and the supporting column member and the heat insulator has a smaller heat conductivity than the supporting column member.

3. The blood sugar level measuring apparatus according to claim 2, wherein the heat insulator is formed of a material having the properties of any of a fiber material, a foaming material, or a micro dust layer material.

4. The blood sugar level measuring apparatus according to claim 2, wherein the heat insulator has a heat conductivity of 0.0005 W/mK to 0.02 W/mK.

5. The blood sugar level measuring apparatus according to claim 1, further comprising at least one supporting column member for installing the blood flow volume measuring unit, wherein the heat transfer prevention means is an end part of the supporting column member which is adjacent to the heat-conducting member and has a smaller diameter at a position adjacent to the heat-conducting member than the maximum diameter of the supporting column member.

6. The blood sugar level measuring apparatus according to claim 5, wherein the end part has point contact with the heat-conducting member.

7. The blood sugar level measuring apparatus according to claim 5, wherein the end part has linear contact with the heat-conducting member.

8. The blood sugar level measuring apparatus according to claim 1, further comprising at least one supporting column member for installing the blood flow volume measuring unit, wherein

the heat transfer prevention means comprises a connecting part projecting from the supporting column member and a holding part which is connected to the connecting part and holds the heat-conducting member.

9. The blood sugar level measuring apparatus according to claim 1, wherein the oxygen volume measuring unit further comprises an optical measuring unit for obtaining blood hemoglobin concentration and hemoglobin oxygen saturation.

10. The blood sugar level measuring apparatus according to claim 9, wherein the optical measuring unit comprises:

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

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

a photodetector for detecting the light with which the body surface has been irradiated.

11. The blood sugar level measuring apparatus according to claim 1, wherein the heat amount measuring unit comprises:

an ambient temperature detector for measuring the ambient temperature; and

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

12. A blood sugar level measuring apparatus comprising:

an ambient temperature measuring unit for measuring the ambient temperature;

a body-surface contact unit to be brought into contact with a body surface;

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

a heat-conducting member disposed in contact with the body-surface contact unit;

a heat insulator disposed in contact with the heat-conducting member;

a contact part for covering an open end of the heat-conducting member in contact with the body-surface contact unit;

an adjacent temperature detector for detecting the temperature of the contact part;

an indirect temperature detector disposed adjacent the heat-conducting member and away from the body-surface contact unit for detecting the temperature at a position distanced away from the body-surface contact unit;

a light source for irradiating the body-surface contact unit with light of at least two different wavelengths;

a photodetector for detecting the light with which the body surface has been irradiated;

a converting unit for converting the outputs from the adjacent temperature detector, the indirect temperature detector, the ambient temperature measuring unit, the radiation heat detector, and the photodetector into individual parameters;

a storage unit for storing the relationships between the parameters and blood sugar levels;

a computing unit for computing a blood sugar level by applying the individual parameters to the relationships stored in the storage unit; and

a display unit for displaying the blood sugar level produced from the computing unit.

13. The blood sugar level measuring apparatus according to claim 12, further comprising at least one supporting column member for installing the heat-conducting member, wherein the heat insulator has a lower heat conductivity than the supporting column member.

14. The blood sugar level measuring apparatus according to claim 12, further comprising at least one supporting column member for installing the heat-conducting member, wherein the heat insulator is disposed between the heat-conducting member and the supporting column member.

15. A blood sugar level measuring apparatus comprising:

an ambient temperature measuring unit for measuring the ambient temperature;

a body-surface contact unit to be brought into contact with a body surface;

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

a heat-conducting member disposed in contact with the body-surface contact unit;

a supporting column member which supports the heat-conducting member and has a smaller diameter at a site adjacent to the heat-conducting member than the maximum diameter of the supporting column member;

a contact part for covering an open end of the heat-conducting member in contact with the body-surface contact unit;

an adjacent temperature detector for detecting the temperature of the contact part;

an indirect temperature detector disposed adjacent the heat-conducting member and away from the body-surface contact unit for detecting the temperature at a position distanced away from the body-surface contact unit;

a light source for irradiating the body-surface contact unit with light of at least two different wavelengths;

a photodetector for detecting the light with which the body surface has been irradiated;

a converting unit for converting the outputs of the adjacent temperature detector, the indirect temperature detector, the ambient temperature measuring unit, the radiation heat detector, and the photodetector into individual parameters;

a storage unit for storing the relationships between the parameters and blood sugar levels;

a computing unit for computing a blood sugar level by applying the individual outputs to the relationships stored in the storage unit; and

a display unit for displaying the blood sugar level produced from the computing unit.

16. The blood sugar level measuring apparatus according to claim 15, wherein the end part has a smaller diameter at a site adjacent to the heat-conducting member than the other parts of the supporting column member.

17. The blood sugar level measuring apparatus according to claim 15, wherein the end part is in contact with the heat-conducting member through linear contact.

18. The blood sugar level measuring apparatus according to claim 15, wherein the end part is in contact with the heat-conducting member through point contact.