Systems and methods of multispectral blood measurement

• US 10,463,283 B2
• Filed: 03/14/2014
• Issued: 11/05/2019
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: Itamar Medical SPRY 2021 Limited Partnership
• Original Assignee: Spry Health, Inc. (Asahi Kasei Corporation)
• Inventors: Ferber, Elad, Cobut, Pierre-Jean
• Primary Examiner(s): Winakur, Eric F
• Assistant Examiner(s): Liu, Chu Chuan
• Application Number:
  US14/214,175
• Publication Number:
  US 20140316226A1
• Time in Patent Office: 2,062 Days
• CPC Class Codes: A61B 2560/045 with a separable interface unit, e.g. for communication
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14535 for measuring haematocrit
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• 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
• CPC Class Codes: A61B 5/743 Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots
• CPC Class Codes: G16H 40/67 for remote operation

Abstract

An exemplary system comprises an energy transmitter, an energy receiver, and an analyzer. The energy transmitter may project energy at a first wavelength and a second wavelength into tissue of a user, the first wavelength and the second wavelength being associated with at least one nutrient of a set of nutrients in blood of the user. The energy receiver may generate a composite signal based on a fraction of the energy at the first wavelength and the second wavelength, the fraction of the energy being received through the tissue of the user. The analyzer may separate the composite signal into a first signal corresponding to the first wavelength and a second signal corresponding to the second wavelength, and detect, in the blood of the user, a concentration of the at least one nutrient of the set of nutrients based on the first signal and the second signal.

Claims

1. A system comprising:

a flexible wrist band;

a plurality of light emitting diodes secured to the flexible wrist band, a first of the plurality of light emitting diodes configured to project energy at a first wavelength into tissue of a wearer and a second of the plurality of light emitting diodes configured to project energy at a second wavelength into the tissue of the wearer, the first wavelength and the second wavelength being associated with different analyte concentrations in blood of the wearer;

at least one photo detector secured to the flexible wrist band, the at least one photo detector being adjacent to the plurality of light emitting diodes and configured to generate a composite signal based on a fraction of the energy at the first wavelength and the second wavelength, the fraction of the energy being reflected by the tissue of the wearer; and

a processor configured to;

separate the composite signal into a first signal corresponding to the first wavelength and a second signal corresponding to the second wavelength, and detect, in the blood of the wearer, a first analyte concentration measurement of a first analyte and a second analyte concentration measurement of a second analyte within the blood of the wearer based on the first signal and the second signal, respectively;

apply a Kalman filter to the first analyte concentration measurement and the second analyte concentration measurement;

compare a result of the application of the Kalman filter to the first analyte concentration measurement and the second analyte concentration measurement with at least one threshold associated with motion of the wearer to determine if at least the first analyte concentration measurement or the second analyte concentration measurement is abnormal as being influenced by the motion of the wearer;

if the first analyte concentration measurement and the second analyte concentration measurement are abnormal based on the comparison, remove abnormal measurements associated with the motion of the wearer; and

if the first analyte concentration measurement and the second analyte concentration measurement are not determined to be abnormal based on the comparison, obtain a first analyte concentration of the first analyte and a second analyte concentration of the second analyte based at least on an assessment of the first analyte concentration measurement and a second analyte concentration measurement in a frequency domain.

2. The system of claim 1, wherein the processor is further configured to determine a set of blood metrics based on the first analyte concentration and the second analyte concentration.

3. The system of claim 2, further comprising a display coupled to the processor, the processor configured to display a user interface on the display, the user interface including at least some of the set of blood metrics.

4. The system of claim 2, wherein the processor is further configured to compare a blood metric of the set of blood metrics to a threshold and to generate an alert if the blood metric exceeds the threshold.

5. The system of claim 2, wherein the set of blood metrics comprises a blood glucose concentration.

6. The system of claim 1, wherein the processor is further configured to determine a first AC component and a first DC component of the first signal and to determine a second AC component and a second DC component of the second signal, wherein the first analyte concentration measurement is detected based on the first AC component and the first DC component, and the second analyte concentration measurement is detected based on the second AC component and the second DC component.

7. The system of claim 1, wherein the first analyte concentration measurement is a measurement of concentration of hemoglobin, triglyceride, bilirubin, protein, albumin, cortisol, or electrolyte.

8. A method comprising:

projecting a first wavelength of energy into tissue of a user;

projecting a second wavelength of energy into the tissue of the user, the first wavelength and the second wavelength being associated with different analyte concentrations in blood of the user;

receiving a fraction of the energy at the first and second wavelengths, the fraction of the energy being reflected by the tissue of the user;

generating a composite signal based on the fraction of the energy at the first wavelength and the second wavelength, the fraction of the energy being reflected by the tissue of the user;

separating, by a processor, the composite signal into a first signal corresponding to the first wavelength and a second signal corresponding to the second wavelength;

detecting, by a processor, a first analyte concentration measurement of a first analyte in the blood of the user based on the first wavelength and a second analyte concentration measurement of a second analyte in the blood of the wearer based on the second wavelength;

applying, by a processor, a Kalman filter to the first analyte concentration measurement and the second analyte concentration measurement;

comparing, by a processor, a result of the application of the Kalman filter to the first analyte concentration measurement and the second analyte concentration measurement with at least one threshold associated with motion of the wearer to determine if the at least the first analyte concentration measurement or the second analyte concentration measurement is abnormal as being influenced by the movement of the user;

if the first analyte concentration measurement and the second analyte concentration measurement are abnormal based on the comparison, remove abnormal measurements associated with movement by the user; and

if the first analyte concentration measurement and the second analyte concentration measurement are not determined to be abnormal based on the comparison, obtain a first analyte concentration of the first analyte and a second analyte concentration of the second analyte based at least on an assessment of the first analyte concentration measurement and the second concentration measurement in a frequency domain.

9. The method of claim 8, further comprising displaying, on a display communicatively coupled to the processor the first analyte concentration measurement.

10. The method of claim 8, further comprising comparing the first analyte concentration to a threshold and generating an alert if the first analyte concentration exceeds the threshold.

11. The method of claim 8, wherein the first analyte concentration comprises a blood glucose concentration.

12. The method of claim 8, further comprising determining a first AC component and a first DC component of the first signal and determining a second AC component and a second DC component of the second signal, wherein the first analyte concentration measurement is detected based on the first AC component and the first DC component, and the second analyte concentration measurement is detected based on the second AC component and the second DC component.

13. The method of claim 8, wherein the first analyte concentration measurement is a measurement of concentration of hemoglobin, triglyceride, bilirubin, protein, albumin, cortisol, or electrolyte.

14. A system comprising:

a flexible wrist band;

a plurality of light emitting diodes secured to the flexible wrist band, a first of the plurality of light emitting diodes configured to project energy at a first wavelength into tissue of a wearer and a second of the plurality of light emitting diodes configured to project energy at a second wavelength into the tissue of the wearer, the first wavelength and the second wavelength being associated with different analyte concentrations in blood of the wearer, the different analyte concentrations being at least two selected from a set of components comprising hemoglobin, triglycerides, bilirubin, protein, albumin, blood pH, Hematocrit, cortisol, and electrolytes;

at least one photo detector secured to the flexible wrist band, the at least one photo detector being adjacent to the plurality of light emitting diodes and configured to generate a composite signal based on a fraction of the energy at the first wavelength and the second wavelength, the fraction of the energy being reflected by the tissue of the wearer; and

a processor configured to;

separate the composite signal into a first signal corresponding to the first wavelength and a second signal corresponding to the second wavelength, and to detect, in the blood of the wearer, a first analyte concentration measurement of a first analyte and a second analyte concentration measurement of a second analyte within the blood of the wearer based on the first signal and the second signal, respectively;

apply a Kalman filter to the first analyte concentration measurement and the second analyte concentration measurement;

compare a result of the application of the Kalman filter to the first analyte concentration measurement and the second analyte concentration measurement with at least one threshold associated with motion of the wearer to determine if at least the first analyte concentration measurement or the second analyte concentration measurement is abnormal as being influenced by the motion of the wearer;

if the first analyte concentration measurement and the second analyte concentration measurement are abnormal based on the comparison, remove abnormal measurements associated with movement by the wearer; and

if the first analyte concentration measurement and the second analyte concentration measurement are not determined to be abnormal based on the comparison, obtain a first analyte concentration of the first analyte and a second analyte concentration of the second analyte based at least on an assessment of the first analyte concentration measurement and the second analyte concentration measurement in a frequency domain.