Metabolic brain measurements in the newborn: Advances in optical technologies

Abstract

Neonatal monitoring in neonatal intensive care is pushing the technological boundaries of newborn brain monitoring in order to improve patient outcome. There is an urgent need of a cot side, real time monitoring for assessment of brain injury severity and neurodevelopmental outcome, in particular for term newborn infants with hypoxic‐ischemic brain injury. This topical review discusses why brain tissue metabolic monitoring is important in this group of infants and introduces the currently used neuromonitoring techniques for metabolic monitoring in the neonatal intensive care unit (NICU). New optical techniques that can monitor changes in brain metabolism together with brain hemodynamics at the cot side are presented. Early studies from these emerging technologies have demonstrated their potential to deliver continuous information regarding cerebral physiological changes in sick newborn infants in real time. The promises of these new tools as well as their potential limitations are discussed.

Optical imaging and spectroscopy for the study of the human brain: status report

“… The power of combining diffuse optical techniques techniques (a) Yellow boxes indicate the physiological measurements that can be achieved non-invasively with diffuse optical techniques, demonstrating the capacity to interrogate from the vascular system down to the mitochondrial and the tricarboxylic acid (TCA) cycle, also called Krebs cycle, for adenosine triphosphate (ATP) energy production (CBF: cerebral blood flow; HbO2: oxygenated hemoglobin; HHb deoxygenated hemoglobin; : cerebral metabolic rate of oxygen; oxCCO: oxidized cytochrome-c-oxidase). Figure modified from Bale et al 94 (b) The BabyLux 95 system combines a two-wavelength time domain near-infrared spectroscopy (TD-NIRS) module with a dual-channel DCS module. 96 It includes highly customizable software suitable for medical personnel with a self-guided software/hardware procedure.…”

Dual-modal metabolic analysis reveals hypothermia-reversible uncoupling of oxidative phosphorylation in neonatal brain hypoxia-ischemia

“…Metabolic brain measurements using optical methods have a great potential in the clinical care of infants 10,38 . In particular, optical CMRO2i measurements may detect irreversible brain damage in neonates suffered from birth asphyxia, similar to MRI-CMRO2 in adult ischemic stroke 17,19 , but clinical application of optical CMRO2i is still in development [11][12][13][14][15] .…”

Two-layered blood-lipid phantom and method to determine absorption and oxygenation employing changes in moments of DTOFs

“…NIRS tissue oximetry enables monitoring vital parameters in real time, reporting on the balance between oxygen supply and consumption. The clinical usefulness of NIRS has been demonstrated by a wide range of clinical applications and trials (reviewed in [ 1 – 9 ]) and the popularity of NIRS continues to grow in part due to the continuous advancements in instrumentation and the resultant increasing number of NIRS systems (reviewed in [ 10 – 15 ]). A significant improvement to NIRS tissue oximetry would be the determination of StO 2 in multiple layers and a means of testing such method.…”

“…When introducing a new method of data analysis or a new system, phantom measurements are a necessary test before conducting in-vivo studies as phantoms allow to study the influence of the instrumental factors and uncertainties for well-defined geometries and optical properties [ 51 ]. There is an ongoing effort towards standardization of system performance tests in the field of NIRS [ 15 , 51 ], which has become increasingly important in part due to the increasing number of NIRS systems [ 10 – 15 ]. Recently, Lanka et al [ 52 ] presented the results of the BitMap campaign, which was a multi-laboratory effort to perform a standardized performance assessment of instruments for diffuse optics, which used the BIP [ 53 ], nEUROPt [ 54 ], and MEDPHOT [ 55 ] protocols.…”