Cerebral venous blood oxygenation monitoring during hyperventilation in healthy volunteers with a novel optoacoustic system

Abstract

Monitoring of cerebral venous oxygenation is useful to facilitate management of patients with severe or moderate traumatic brain injury (TBI). Prompt recognition of low cerebral venous oxygenation is a key to avoiding secondary brain injury associated with brain hypoxia. In specialized clinical research centers, jugular venous bulb catheters have been used for cerebral venous oxygenation monitoring and have demonstrated that oxygen saturation < 50% (normal range is 55-75%) correlates with poor clinical outcome. We developed an optoacoustic technique for noninvasive monitoring of cerebral venous oxygenation. Recently, we designed and built a novel, medical grade optoacoustic system operating in the near-infrared spectral range for continuous, real-time oxygenation monitoring in the superior sagittal sinus (SSS), a large central cerebral vein. In this work, we designed and built a novel SSS optoacoustic probe and developed a new algorithm for SSS oxygenation measurement. The SSS signals were measured in healthy volunteers during voluntary hyperventilation, which induced changes in SSS oxygenation. Simultaneously, we measured exhaled carbon dioxide concentration (EtCO 2 ) using capnography. Good temporal correlation between decreases in optoacoustically measured SSS oxygenation and decreases in EtCO 2 was obtained. Decreases in EtCO 2 from normal values (35-45 mmHg) to 20-25 mmHg resulted in SSS oxygenation decreases by 3-10%. Intersubject variability of the responses may relate to nonspecific brain activation associated with voluntary hyperventilation. The obtained data demonstrate the capability of the optoacoustic system to detect in real time minor changes in the SSS blood oxygenation.

Photoacoustic Imaging in Oncology: Translational Preclinical and Early Clinical Experience

“…In this review, basics and general principles of photoacoustic imaging along with cancer-specific applications of photoacoustic imaging that can be readily translated to clinic were discussed. With the availability of commercial preclinical imaging systems along with the ability to build relatively inexpensive custom systems, an increase in photoacoustic imaging investigation rate is expected in the coming years for various clinical applications, including and beyond cancer detection and characterization (47,(116)(117)(118)(119)(120)(121)(122)(123) absorption was reported, implying that the mean optical absorption increases almost monotonically with the severity of cervical cancer.…”

Monitoring cerebral venous blood oxygenation in neonates with a medical-grade optoacoustic system

“…We developed and built a medical-grade optoacoustic system, described in detail in [16][17][18][19][20] . The system utilizes an optical parametric oscillator (OPO), the Opolette HE 532 (Opotek Inc., Carlsbad, CA), as a source of pulsed nearinfrared (NIR) light in the wavelength range of 680-950 nm, a pulse width of about 6 ns, and a pulse repetition rate of 20 Hz.…”

“…The SSS, a large central cerebral vein, drains all blood from the brain and represents an important site of monitoring. Recently, we developed and built a medical-grade optoacoustic system for optoacoustic imaging, monitoring, and sensing [16][17][18][19][20][21] . In this work we performed pilot clinical tests of the system in the reflection and transmission modes in infants, including LBW and VLBW infants.…”

Optoacoustic measurements of human placenta and umbilical blood oxygenation

“…The system utilizes an optical parametric oscillator (OPO), the Opolette HE 532 (Opotek Inc., Carlsbad, CA), as a source of pulsed near-infrared (NIR) light in the wavelength range of 680-950 nm with a pulse width of about 6 ns and a pulse repetition rate of 20 Hz. Wide-band, highly-sensitive optoacoustic probes were developed in our laboratory for monitoring, imaging, and sensing in reflection and transmission modes [1][2][3][4][5][11][12][13][14][15][16][17][18][19][20][21][22][23] . The laser light was delivered to the probe through fiber-optic systems specially developed for the reflection and transmission modes.…”