scholarly journals Effects of wavelength-dependent fluence attenuation on the noninvasive photoacoustic imaging of hemoglobin oxygen saturation in subcutaneous vasculature in vivo

2008 ◽  
Author(s):  
Hao F. Zhang ◽  
Konstantin Maslov ◽  
Lihong V. Wang
Keyword(s):  
Oxygen Saturation ◽  
Photoacoustic Imaging ◽  
Hemoglobin Oxygen Saturation

Hemoglobin oxygen saturation measurements using resonance Raman intravital microscopy

2005 ◽  
Vol 289 (1) ◽  
pp. H488-H495 ◽  
Author(s):  
Ivo P. Torres Filho ◽  
James Terner ◽  
Roland N. Pittman ◽  
Leonardo G. Somera ◽  
Kevin R. Ward
Keyword(s):  
Oxygen Saturation ◽  
Raman Spectra ◽  
Raman Band ◽  
Ultraviolet Region ◽  
Excitation Wavelength ◽  
Isolated Cells ◽  
Light Power ◽  
Hemoglobin Oxygen Saturation ◽  
Rat Mesentery

A system is described for in vivo noninvasive measurements of hemoglobin oxygen saturation (HbO2Sat) at the microscopic level. The spectroscopic basis for the application is resonant Raman enhancement of Hb in the violet/ultraviolet region, allowing simultaneous identification of oxy- and deoxyhemoglobin with the same excitation wavelength. The heme vibrational bands are well known, but the technique has never been used to determine microvascular HbO2Sat in vivo. A diode laser light (power: 0.3 mW) was focused onto sample areas 15–30 μm in diameter. Raman spectra were obtained in backscattering geometry by using a microscope coupled to a spectrometer and a cooled detector. Calibration was performed in vitro by using glass capillaries containing blood at several Hb concentrations, equilibrated at various oxygen tensions. HbO2Sat was estimated using the Raman band intensities at 1,360 and 1,375 cm−1. Glass capillary path length and Hb concentration had no effect on HbO2Sat estimated from Raman spectra. In vivo observations were made in blood flowing in microvessels of the rat mesentery. The Hb Raman peaks observed in oxygenated and deoxygenated blood were consistent with earlier Raman studies that used Hb solutions and isolated cells. The method allowed HbO2Sat determinations in the whole range of arterioles, venules, and capillaries. Tissue transillumination allowed diameter and erythrocyte velocity measurements in the same vessels. Raman microspectroscopy offers distinct advantages over other currently used techniques by providing noninvasive and reliable in vivo determinations of HbO2Sat in thin tissues as well as in solid organs and tissues, which are unsuitable for techniques requiring transillumination.

scholarly journals In-Vivo Functional and Structural Retinal Imaging Using Multiwavelength Photoacoustic Remote Sensing Microscopy and Optical Coherence Tomography

2021 ◽  
Author(s):  
Zohreh Hosseinaee ◽  
Nicholas Pellegrino ◽  
Nima Abbasi ◽  
Tara Amiri ◽  
James A. Tummon Simmons ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Coherence Tomography ◽  
Oxygen Saturation ◽  
Imaging Technique ◽  
Photoacoustic Imaging ◽  
Retinal Imaging ◽  
Optical Coherence ◽  
Swept Source ◽  
First Time

Abstract A multiwavelength photoacoustic remote sensing (PARS) microscope is combined with swept-source optical coherence tomography and applied to in-vivo, non-contact retinal imaging. Building on the proven strength of multiwavelength PARS imaging, the system is applied for estimating retinal oxygen saturation in the rat eye. The capability of the technology is demonstrated by imaging both microanatomy and the microvasculature of the retina in-vivo. To our knowledge, this is the first time a non-contact photoacoustic imaging technique is employed for in-vivo oxygen saturation measurement in the retina.

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