Method for representations of network-dependent features of the hemoglobin signal in living tissues for detection of breast cancer and other applications
A non-invasive method of detecting anomalous tissue, such as cancerous or injured tissue, in a patient. At least two hemoglobin signal components of hemoglobin levels in at least one segment of tissue of the patient are non-invasively measured over time. Time varying changes of at least a first of the hemoglobin signal components are measured with respect to at least time varying changes of a second of the hemoglobin signal components. A co-varying coordinate system of the time varying changes is generated. Any anomalous tissue in the measured segment of tissue is detected from a signature of the measured segment of tissue in the co-varying coordinate system which differs from a signature of non-anomalous tissue in the co-varying coordinate system. Preferably, five hemoglobin signal components are measured: oxyHb, deoxyHb, total Hb (totalHb=oxyHb+deoxy Hb), Hb oxygen saturation (HbO 2 Sat=(oxyHb/totalHb)*100), and tissue-hemoglobin oxygen exchange HbO 2 Exc (deoxyHb−oxyHb).
1. A method of evaluating brain function in a subject, the method comprising:
(a) illuminating a first brain region of the subject and measuring time varying changes of tissue-Hb oxygen exchange (HbO 2 Exc) and at least one additional Hb signal component of the first brain region;
(b) illuminating a second brain region of the subject and measuring time varying changes of HbO 2 Exc and at least one additional Hb signal component of the second brain region, wherein the second brain region is normal, and wherein the at least one additional Hb signal component of the first brain region and the at least one additional Hb signal component of the second brain region are the same;
(c) generating a signature for the first brain region based on the measured time varying changes of HbO 2 Exc and the at least one additional Hb signal component of the first brain region;
(d) generating a signature for the second brain region based on the measured time varying changes of HbO 2 Exc and the at least one additional Hb signal component of the second brain region;
(e) comparing the signature for the first brain region and the signature for the second brain region to identify a difference between the signature for the first brain region and the signature for the second brain region; and
(f) evaluating brain function of the subject based on the difference between the signature for the first brain region and the signature for the second brain region.
2. The method of claim 1 , wherein the brain function in the subject indicates a presence of a disease.
3. The method of claim 2 , wherein the disease is cancer.
4. The method of claim 1 , wherein the brain function in the subject indicates a presence of a neuropsychiatric disorder.
5. The method of claim 1 , wherein the brain function in the subject indicates a presence of a respiratory challenge.
6. The method of claim 1 , wherein the brain function in the subject is used to monitor an effect of a drug.
7. The method of claim 1 , wherein the brain function is used to evaluate the presence of trauma.
8. The method of claim 1 , wherein the brain function is used to optimize a performance of a neural implant.
9. The method of claim 1 , wherein the illuminating uses contact illumination.
10. The method of claim 9 , wherein the illuminating comprises contacting a region of a head of the subject with an optical fiber.
11. The method of claim 1 , wherein the illuminating the first brain region uses non-contact illumination.
12. The method of claim 1 , wherein the illuminating the first brain region uses near-infrared light.
13. The method of claim 1 , wherein the illuminating the first brain region uses a light source that produces two wavelengths of light simultaneously.
14. The method of claim 13 , wherein the two wavelengths of light are 760 nm and 830 nm.
15. The method of claim 1 , wherein the measuring is performed at a resting state.
16. The method of claim 1 , wherein the measuring time varying changes of tissue-Hb oxygen exchange (HbO 2 Exc) and the additional Hb signal component of the first brain region comprises detecting, with a receiver, light that is diffusely transmitted by the first brain region.
17. The method of claim 1 , wherein the measuring time varying changes of tissue-Hb oxygen exchange (HbO 2 Exc) and the additional Hb signal component of the first brain region comprises detecting, with a receiver, light that is back-reflected from the first brain region.
18. The method of claim 1 , wherein the additional Hb signal component comprises Hb oxygen saturation, wherein Hb oxygen saturation is defined as HbO 2 Sat=(oxygenated Hb/total Hb)×100.
19. The method of claim 1 , wherein the at least one additional Hb signal component comprises oxygenated hemoglobin (oxyHb).
20. The method of claim 1 , wherein the at least one additional Hb signal component comprises deoxygenated hemoglobin (deoxyHb).
21. The method of claim 1 , wherein the at least one additional Hb signal component comprises total hemoglobin (Hb).