Device for Determining the Glucose Level in Body Tissue

• US 20090312615A1
• Filed: 11/10/2005
• Published: 12/17/2009
• Est. Priority Date: 11/10/2005
• Status: Active Grant

• Current Assignee: Biosigns Pte Limited
• Original Assignee: Biovotion AG (Biofourmis AG)
• Inventors: Stalder, Gianluca, Huber, Daniel, Caduff, Andreas, Talary, Mark Stuart, Dewarrat, Francois
• Granted Patent: US 9,713,447 B2
• Time in Patent Office: Days
• US Class Current: 600/316
• CPC Class Codes: A61B 2560/0242 adapted to measure environmental factors, e.g. temperature, pollution
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/0531 Measuring skin impedance
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61B 5/721 using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured

Abstract

The apparatus for the non-invasive glucose detection comprises an electrical detection device (2) for measuring the response of the tissue or blood to an electric field at low frequencies below 1 MHz and at high frequencies above 10 MHz. The former is primarily dominated by skin hydration and sweat, while the latter contains contributions from the current glucose level. Combining the two signals allows an increased degree of accuracy. The apparatus further comprises a force or acceleration sensor (4, 5), which allows to detect the pressure of the apparatus against the skin and/or quick movements. Further sensor modules, such as a temperature sensor (6) or alternative perfusion sensor (7), improve the accuracy of the measured result.

Claims

1. An apparatus for determining a glucose level in body tissue or blood comprising

an electrical detection device having an electrode arrangement for applying an electric field to the tissue or blood for measuring at least one first parameter describing a response of said tissue or blood to said electric field,

an optical detection device comprising a light source and a light detector for measuring at least one second parameter describing a transmission or reflection of light by said tissue or blood, and

evaluation circuitry for determining the glucose level from a combination of said first and second parameter.

2. The apparatus of claim 1 further comprising an AC voltage source with for applying voltages of different frequencies to said electrode arrangement.

3. The apparatus of claim 1 wherein said optical detection device is adapted to determine said second parameter for at least a first and a second wavelength.

4. The apparatus of claim 3 wherein said first wavelength is in the visible spectrum.

5. The apparatus of claim 3 wherein said second wavelength is in the near infrared spectrum.

6. The apparatus of claim 1 wherein said light source is located to emit light through said electrode arrangement and/or said light detector is located to measure light transmitted through said electrode arrangement for measuring said second parameter in a part of said tissue or blood experiencing said electric field.

7. The apparatus of claim 6 wherein said light source and/or said light detector are located to emit or measure light transmitted through gaps in said electrode arrangement.

8. The apparatus of claim 1 wherein said optical detection device comprises a waveguide for transmitting incoming and/or outgoing light.

9. The apparatus of claim 8 wherein said electrode arrangement is planar and has first surface for facing said body tissue or blood and second opposite surface, wherein said waveguide is located at said second surface.

10. An apparatus for determining a glucose level in body tissue or blood, in particular of any of the preceding claims, comprising

a detection device for non-invasively measuring a glucose parameter of said tissue or blood depending on said glucose level,

a force sensor for measuring a force parameter indicative of a force between said apparatus and said tissue or blood, and

evaluation circuitry for determining the glucose level.

11. The apparatus of claim 10 further comprising a wristband or adhesive tape wherein said force sensor is adapted to measure a force applied by said wristband or adhesive tape.

12. The apparatus of claim 10 comprising a first and a second housing part and a wristband connected to said first housing part, wherein said detection device is arranged in or on said second housing part and wherein said force sensor is adapted to measure a force between said first and said second housing parts.

13. The apparatus of claim 10 wherein said evaluation circuitry is adapted to determine the glucose concentration from a combination of said parameter and a signal from said force sensor.

14. The apparatus of claim 10 wherein said apparatus is adapted to suppress at least part of an operation of said apparatus if fluctuations of a signal from said force sensor exceed a threshold.

15. The apparatus of claim 10 wherein said apparatus is adapted to issue an alert if fluctuations of a signal from said force sensor exceed a given threshold.

16. An apparatus for determining a glucose level in body tissue or blood, in particular of any of the preceding claims, comprising

a detection device for non-invasively measuring a glucose parameter of said tissue or blood depending on said glucose level,

an acceleration sensor for measuring an acceleration of said apparatus, and evaluation circuitry for determining the glucose level.

17. The apparatus of claim 16 wherein said apparatus is adapted to suppress at least part of an operation of said apparatus if said acceleration exceeds a threshold.

18. The apparatus of claim 16 wherein said apparatus is adapted to issue an alert if a signal from said acceleration sensor exceeds a given threshold.

19. The apparatus of claim 10 wherein said detection device comprises an electrode arrangement for applying an electric field to the tissue or blood for measuring said glucose parameter.

20. An apparatus for determining a glucose level in body tissue or blood, in particular of any of the preceding claims, comprising an electrical detection device having an electrode arrangement for applying an electric field to the tissue or blood, wherein said detection device is adapted to measure

at least one first parameter describing a response of said tissue or blood to a field generated by said electrode arrangement at a frequency of said field above 10 MHz and

at least one second parameter describing a response of said tissue or blood to the field generated by said electrode arrangement at a frequency of said field below 10 MHz, in particular below 1 MHz,

said apparatus further comprising evaluation circuitry for determining the glucose level from a combination of said first and second parameter.

21. The apparatus of claim 20 wherein said electrode arrangement comprises first electrodes for measuring said first parameter and second electrodes for measuring said second parameter.

22. The apparatus of claim 20 comprising a first and a second electrode arrangement for applying an electric field to the tissue or blood for measuring first and second parameters describing a response of said tissue or blood to said electric field, wherein said first and said second electrode arrangement have different geometries.

23. The apparatus of claim 22 wherein each electrode arrangement comprise a first and a second electrode separated by a gap, wherein the gap of the first electrode arrangement has a smaller width than the gap of the second electrode arrangement.

24. The apparatus of claim 23 wherein said first and said second electrode arrangement have a common first electrode.

25. The apparatus of claim 23, wherein the second electrode of the first electrode arrangement has smaller width than the second electrode of the second electrode arrangement.

26. The apparatus of claim 20 comprising an optical detection device having a light source and a light detector for measuring at least one parameter describing a transmission and/or reflection by said tissue or blood of light of a wavelength in the range of 450 to 800 nm, in particular at 550 and/or 700 nm.

27. The apparatus of claim 20 further comprising an ultrasonic detector.

28. The apparatus of claim 1 further comprising an electrical detection device having an electrode arrangement for applying an electric field to the tissue or blood, wherein said detection device is adapted to measure at least one parameter describing a response of said tissue or blood to a field generated by said electrode arrangement at a frequency of said field below 10 MHz, in particular 1 MHz.

29. The apparatus of claim 1 further comprising an electrical detection device having an electrode arrangement for applying an electric field to the tissue or blood, wherein said detection device is adapted to measure at least one parameter describing a response of said tissue or blood to a field generated by said electrode arrangement at a frequency of said field of at least 1 kHz.

30. The apparatus of claim 1 further comprising an electrical detection device having an electrode arrangement for applying an electric field to the tissue or blood, wherein said detection device (2) is adapted to measure a first parameter at a frequency between 1 kHz and 100 kHz and a second parameter at a frequency between 100 kHz and 1 MHz.