VASCULAR OXIMETRY SYSTEM

• US 20170055893A1
• Filed: 08/31/2015
• Published: 03/02/2017
• Est. Priority Date: 08/31/2015
• Status: Active Grant

• Current Assignee: Trustees of Tufts College
• Original Assignee: Tufts University
• Inventors: Kainerstorfer, Jana M., Sassaroli, Angelo, Fantini, Sergio
• Granted Patent: US 11,219,392 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7253 characterised by using transforms

Abstract

A method for determining a hemoglobin saturation of a volume-oscillating vascular compartment in tissue includes receiving data representing measurements of a number of oscillating hemoglobin concentrations from the tissue and determining the hemoglobin saturation of the volume-oscillating vascular compartment to exclude an effect of an oscillating rate of supply of oxygenated blood to a portion of the tissue including removing a first contribution on one or more of the oscillating hemoglobin concentration measurements from at least one of the measurements, the first contribution being phase offset relative to said measurements.

Claims

1. A method for determining a hemoglobin saturation of a volume-oscillating vascular compartment in tissue, the method including

receiving data representing measurements of a plurality of oscillating hemoglobin concentrations from the tissue;

determining the hemoglobin saturation of the volume-oscillating vascular compartment to exclude an effect of an oscillating rate of supply of oxygenated blood to a portion of the tissue including removing a first contribution on one or more of the oscillating hemoglobin concentration measurements from at least one of the measurements, the first contribution being phase offset relative to said measurements.

2. The method of claim 1 wherein the plurality of oscillating hemoglobin concentrations from the tissue include a measured concentration of oxygenated hemoglobin, a measured concentration of deoxygenated hemoglobin, and a total hemoglobin concentration.

3. The method of claim 1 wherein the plurality of oscillating hemoglobin concentrations oscillate at a frequency associated with a physiological function.

4. The method of claim 3 wherein the plurality of oscillating hemoglobin concentrations oscillate at a cardiac frequency.

5. The method of claim 3 wherein the plurality of oscillating hemoglobin concentrations oscillate at a respiratory frequency.

6. The method of claim 1 wherein the plurality of oscillating hemoglobin concentrations oscillate at a physically induced frequency.

7. The method of claim 1 wherein the effect of the oscillating rate of supply of oxygenated blood to the portion of the tissue includes an oscillation in the measured concentration of oxygenated hemoglobin and an oscillation in the measured concentration of deoxygenated hemoglobin due to oscillations in blood flow to the portion of the tissue.

8. The method of claim 7 wherein the oscillation in the measured concentration of oxygenated hemoglobin and the oscillation in the measured concentration of deoxygenated hemoglobin are at least in part due to diffusion of oxygen from blood to the portion of the tissue.

9. The method of claim 1 wherein the portion of the tissue includes a capillary compartment of the tissue.

10. The method of claim 1 wherein the volume-oscillating vascular compartment includes an arterial compartment.

11. The method of claim 1 wherein the volume-oscillating vascular compartment includes a venous compartment.

12. The method of claim 1 wherein the volume-oscillating vascular compartment includes a mixture of an arterial compartment and a venous compartment.

13. The method of claim 12 further comprising determining a first fraction of the hemoglobin saturation associated with the venous compartment and a second fraction of the hemoglobin saturation associated with the arterial compartment.

14. The method of claim 13 wherein the second fraction of the hemoglobin saturation is determined based on a blood pressure measurement.

15. The method of claim 13 wherein the first fraction and the second fraction are determined based on an empirically determined ratio.

16. The method of claim 1 wherein removing the first contribution on the one or more oscillating hemoglobin concentration measurements from the at least one measurement includes receiving an empirically derived representation of the phase offset.

17. The method of claim 1 wherein removing the first contribution on the one or more oscillating hemoglobin concentration measurements from the at least one measurement includes receiving a representation of the phase offset, the representation being inferred using a coherent hemodynamics spectroscopy model.

18. A system for determining a hemoglobin saturation of a volume-oscillating vascular compartment in tissue, the system including

an input for receiving data representing measurements of a plurality of oscillating hemoglobin concentrations from the tissue;

and

an oximetry processing module for determining the hemoglobin saturation of the volume-oscillating vascular compartment to exclude an effect of an oscillating rate of supply of oxygenated blood to a portion of the tissue including removing a first contribution on one or more of the oscillating hemoglobin concentration measurements from at least one of the measurements, the first contribution being phase offset relative to said measurements.

19. The system of claim 18 further comprising a sensor for obtaining the data representing measurements of the plurality of hemoglobin concentrations from the tissue and providing the data to the input.

20. The system of claim 18 further comprising an output for providing the determined hemoglobin saturation of the volume-oscillating vascular compartment.

21. The system of claim 20 further comprising a display device for receiving a representation of the determined hemoglobin saturation of the volume-oscillating vascular compartment from the output and presenting the representation of the determined hemoglobin saturation of the volume-oscillating vascular compartment.

22. The system of claim 18 wherein the effect of the oscillating rate of supply of oxygenated blood to the portion of the tissue includes an oscillation in the measured concentration of oxygenated hemoglobin and an oscillation in the measured concentration of deoxygenated hemoglobin due to oscillations in blood flow to the portion of the tissue.

23. The system of claim 18 wherein removing the first contribution on the one or more oscillating hemoglobin concentration measurements from the at least one measurement includes receiving an empirically derived representation of the phase offset.

24. The system of claim 18 wherein removing the first contribution on the one or more oscillating hemoglobin concentration measurements from the at least one measurement includes receiving a representation of the phase offset, the representation being inferred using a coherent hemodynamics spectroscopy model.