Optical oximetry of volume-oscillating vascular compartments: contributions from oscillatory blood flow
| Autor: | Sergio Fantini, Angelo Sassaroli, Jana M. Kainerstorfer |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Adult
Male Materials science Biomedical Engineering Special Section on Optical Diagnostic and Biophotonic Methods from Bench to Bedside chemistry.chemical_element Hemodynamics Blood volume 01 natural sciences Oxygen 010309 optics Biomaterials 03 medical and health sciences Hemoglobins 0302 clinical medicine Nuclear magnetic resonance 0103 physical sciences Respiration medicine Humans Oximetry Blood Volume Spectroscopy Near-Infrared medicine.diagnostic_test Signal Processing Computer-Assisted Blood flow Middle Aged Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials Pulse oximetry chemistry Anesthesia Cerebrovascular Circulation Oxyhemoglobins Female Hemoglobin Saturation (chemistry) 030217 neurology & neurosurgery |
| Zdroj: | Journal of biomedical optics. 21(10) |
| ISSN: | 1560-2281 |
| Popis: | We present a quantitative analysis of dynamic diffuse optical measurements to obtain oxygen saturation of hemoglobin in volume oscillating compartments. We used a phasor representation of oscillatory hemodynamics at the heart rate and respiration frequency to separate the oscillations of tissue concentrations of oxyhemoglobin (O) and deoxyhemoglobin (D) into components due to blood volume (subscript V V ) and blood flow (subscript F F ): O=O V +O F O=OV+OF , D=D V +D F D=DV+DF . This is achieved by setting the phase angle Arg(O F )−Arg(O) Arg(OF)−Arg(O) , which can be estimated by a hemodynamic model that we recently developed. We found this angle to be −72 deg −72 deg for the cardiac pulsation at 1 Hz, and −7 deg −7 deg for paced breathing at 0.1 Hz. Setting this angle, we can obtain the oxygen saturation of hemoglobin of the volume-oscillating vascular compartment, S V =|O V |/(|O V |+|D V |) SV=|OV|/(|OV|+|DV|) . We demonstrate this approach with cerebral near-infrared spectroscopy measurements on healthy volunteers at rest (n=4 n=4 ) and during 0.1 Hz paced breathing (n=3 n=3 ) with a 24-channel system. Rest data at the cardiac frequency were used to calculate the arterial saturation, S (a) S(a) ; over all subjects and channels, we found ⟨S V ⟩=⟨S (a) ⟩=0.96±0.02 ⟨SV⟩=⟨S(a)⟩=0.96±0.02 . In the case of paced breathing, we found ⟨S V ⟩=0.66±0.14 ⟨SV⟩=0.66±0.14 , which reflects venous-dominated hemodynamics at the respiratory frequency. |
| Databáze: | OpenAIRE |
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