Optoacoustic technique for noninvasive monitoring of blood oxygenation: a feasibility study

Abstract

Replacement of invasive monitoring of cerebral venous oxygenation with noninvasive techniques offers great promise in the management of life-threatening neurologic illnesses including traumatic brain injury. We developed and built an optoacoustic system to noninvasively monitor cerebral venous oxygenation; the system includes a nanosecond Nd:YAG laser and a specially designed optoacoustic probe. We tested the system in vitro in sheep blood with experimentally varied oxygenation. Our results demonstrated that (1) the amplitude and temporal profile of the optoacoustic waves increase with blood oxygenation in the range from 24% to 92%, (2) optoacoustic signals can be detected despite optical and acoustic attenuation by thick bone, and (3) the system is capable of real-time and continuous measurements. These results suggest that the optoacoustic technique is technically feasible for continuous, noninvasive monitoring of cerebral venous oxygenation.

Quantitative spectroscopic photoacoustic imaging: a review

“…Savateeva et al 65 used a broadband detector (∼40 MHz) to measure the exponential slope of the PA signal in order to estimate the attenuation coefficient and showed that it varied linearly with the level of oxygen saturation at 532, 757, and 1064 nm wavelengths. Esenaliev et al 66 showed a similar result at 1064 nm with a lower bandwidth transducer. However, none of these authors provided estimates of absolute sO 2 .…”

Optical clearing of biological tissues: prospects of application in medical diagnostics and phototherapy

“…The main applications of the photoacoustic (PA) method are in the field of visualisation of strongly absorbing objects, such as blood vessels [263][264][265] and tumours [266]. This method can be also used for imaging of subcutaneous structures [267] and measuring the blood oxygenation [268]. The quality of the PA signal depends upon the penetration depth of the optical signal and the damping of the acoustic signal.…”

Exact series reconstruction in photoacoustic tomography with circular integrating detectors

“…PAT presents a hybrid imaging technique that combines the advantages of optical (high contrast) and ultrasound imaging (high resolution). It has proven great potential for important medical applications including cancer diagnostics [16,21] and imaging of vasculature [7,15].…”