SYSTEM FOR NONINVASIVE OPTICAL MEASUREMENTS OF PHYSIOLOGICAL PROPERTIES IN TISSUE

• US 20150190063A1
• Filed: 10/19/2011
• Published: 07/09/2015
• Est. Priority Date: 10/19/2011
• Status: Active Grant

• Current Assignee: Biosigns Pte Limited
• Original Assignee: Biovotion AG (Biofourmis AG)
• Inventors: Talary, Mark, Caduff, Andreas, Zakharov, Pavel
• Granted Patent: US 9,526,431 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/1107 Measuring contraction of parts of the body, e.g. organ, muscle apparatus for measuring work or force in general G01L
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• 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

Embodiments of the present invention comprise systems and methods for noninvasion measurements of physiological properties of tissues. The system comprises a light emitter, an optical detector, a mechanical sensor and a processor. The light emitter is capable of emitting light of at least two different wavelengths and comprises at least one light source. The processor is capable of evaluating physiological properties of the tissues from measurements of the optical and the mechanical sensor. More precisely, the processor is capable of evaluating physiological properties of venous blood by using data measured by the mechanical sensor and the optical detector. For example, the oxygenation of venous blood can be measured. Furthermore, the systems can optionally comprise a light emitter which emits three wavelengths and/or the light emitter and the optical detector are arranged in reflection geometry and are located at a distance of at most 10 mm from each other.

Claims

1. A system for noninvasive measurements of physiological properties of tissue comprising

a) an optical sensor comprising a light emitter and an optical detector, where the light emitter comprises at least one light:

source and is capable of emitting light;

of at least two different wavelengths,

b) a mechanical sensor,

c) a processor capable of evaluating physiological properties from measurements of the optical sensor, wherein the processor is capable of evaluating physiological properties of venous blood by using data measured by the mechanical sensor and data measured by the optical sensor.

2. The system according to claim 1, wherein the processor is capable of evaluating the oxygenation of venous blood and/or arterial blood.

3. The system according to claim 1, wherein the processor is capable of evaluating a physiological properly of venous blood using movement of blood in the tissue caused by natural movement of the tissue.

4. The system according to claim 1, wherein the processor is capable of recognizing variations of the optical signal related to a heart pulse wave and is capable of including these variations in the evaluation of physiological properties of the venous and/or arterial blood.

5. The system according to claim 1, wherein the mechanical sensor comprises an accelerometer and/or force sensor.

6. The system according to claim 1, wherein the system comprises at least two optical detectors for spatially resolved measurements.

7. The system according to claim 1, wherein the light emitter is capable of emitting light of a third wavelength (in particular light in a green wavelength range) and that the optical detector is capable of measuring light of the third wavelength.

8. The system according to claim 1, wherein the processor is capable of using a dynamic light scattering technique detect the heart rate and/or at least one heart pulse wave parameter.

9. The system according to claim 1, wherein the light emitter and the optical detector are arranged in a reflection geometry and are located close to each other.

10. The system according to claim 1, wherein the system comprises a dielectric sensor which allows the system to discriminate different tissue components and volume fractions.

11. A method for measurements of physiological properties of tissue comprising the steps;

a) emitting light with at least two wavelengths,

b) measuring a light intensity optically after the emitted light has interacted with the tissue,

c) performing a mechanical measurement of the tissue closely synchronized with the step of measuring optically,

d) evaluating physiological properties of the tissue from the combination of optical and the mechanical measurements, wherein in the step of evaluating, a physiological property of venous blood is evaluated.

12. The method according to claim 11, wherein the step of measuring optically comprises performing at least two optical measurements simultaneously for spatially resolved measurements.

13. The method according to claim 11, wherein the step of measuring optically the light is penetrating only upper layers of the tissue.

14. A system for noninvasive measurements of physiological properties of tissue, comprising:

a) an optical sensor comprising a light emitter and an optical detector, where the light emitter comprises at least one light source and is capable of emitting light of at least three different wavelengths, and

b) a processor capable of evaluating physiological properties from measurements of the optical sensor.

15. A system for noninvasive measurements of physiological properties of tissue, comprising:

a) an optical sensor comprising a light emitter and an optical detector, where the light emitter comprises at least one light source and is capable of emitting light of at least two different wavelengths, and

b) a processor capable of evaluating physiological properties from measurements of the optical sensor, wherein the light emitter and the optical detector are arranged in a reflection geometry and are located at a distance of at most 10 mm from each other.

16. A system for noninvasive measurements of physiological properties of tissue comprising:

a) an optical sensor comprising a light emitter and an optical detector, where the light emitter comprises at least one light source and is capable of emitting light of at least two different wavelengths,

b) a mechanical sensor comprising an accelerometer,

c) a processor capable of evaluating physiological properties from measurements of the optical sensors, wherein the processor is structured and adapted to evaluate physiological properties of venous blood by using data measured by the mechanical sensor and data measured by the optical sensor.

17. The system of claim 16, wherein said processor is structured and adapted to statistically correlating signals from said accelerometer with optical signals measured by said optical sensor, and

determining portions of the optical signals correlated with the signals from the accelerometer to be of venous origin and uncorrected signal portions to be of arterial origin,

18. A method for measurement of physiological properties of tissue comprising the steps of:

a) emitting light with at least two wavelengths,

b) measuring an optical signal based on a light intensity after the emitted light has interacted with the tissue,

c) performing an accelerometer measurement synchronized with the step of measuring an optical signal,

d) evaluating a physiological property of venous blood from a combination of said optical signal and said accelerometer measurement.

19. The meshed of claim 18, wherein said step of evaluating the physiological property of venous blood comprises the step of statistically correlating said accelerometer measurement with said optical signal.

20. The method of claim 19, further comprising the steps of determining portions of the optical signal correlated with the accelerometer measurement to be of venous origin and uncorrected signal portions to be of arterial origin.