Noninvasive Monitoring of Metabolism and Hemodynamics Using Super-Continuum Infrared Spectroscopy of a Cytochrome C Oxidase (SCISCCO) Instrument

Abstract

We present a novel, noninvasive, super-continuum infrared spectroscopy of cytochrome c oxidase (SCISCCO) system for simultaneously measuring hemodynamic and metabolic parameters, and we demonstrate its utility by applying it to lab calibration tests, human studies, and swine animal studies. The system optically assays the redox state of cytochrome c oxidase (CCO), as well as traditional markers including oxygenated (HbO) and deoxygenated (HbR) hemoglobin. To demonstrate in vivo feasibility, the measured responses of oxygenation and CCO responses to acute ischemia on the arm and forehead in human participants are compared to data from the literature. The validated SCISCCO system is then applied in human studies to measure cerebral oxygenation and the redox state of CCO in participants during an attention test protocol. We show that the redox state of CCO and hemodynamics measured by the SCISCCO system are consistent with the physiological hypothesis established in prior studies. To enable use of the SCISCCO system in laboratory and hospital settings as well as transportation to remote locations, a cart-based SCISCCO prototype system has also been developed. The cart-based SCISCCO prototype is applied to swine animal models undergoing induction of hemorrhagic shock followed by partial resuscitative endovascular balloon occlusion of the aorta (pREBOA). The pilot study demonstrates the feasibility of using the SCISCCO instrument within the context of existing protocols and validates the instrument’s measurements against the physiological and hemodynamic parameters measured by other conventional devices.

Review of measurements and imaging of cytochrome-c-oxidase in humans using near-infrared spectroscopy: an update

“…(i): SCISSCO. High-level system schematic of cart-based SCISSCO prototype [ 41 ] , (ii): 8λ UCL. Schematic of single module containing two multi-wavelength sources and four detectors [ 42 ], (iii): 8λ UCL.…”

“…The use of a stable, high-intensity supercontinuum laser gives this system the advantage of a very high SNR and lower measurement errors, however the use of a single source and channel separation restricts the ability for depth measurements. The SCISSCO device [ 41 ] consists of a supercontinuum laser emitting between 759-897nm, and data is taken at 3nm intervals with a spectrometer to resolve HbO, HbR and oxCCO at a single 30mm separation. Due to the speed of the mechanical rotation of the grating in the spectrometer, data acquisition was limited to 17 seconds giving a sampling frequency of 0.06Hz.…”

“…The SCISSCO device [ 41 ] consists of a supercontinuum laser emitting between 759-897nm, and data is taken at 3nm intervals with a spectrometer to resolve HbO, HbR and oxCCO at a single 30mm separation. Due to the speed of the mechanical rotation of the grating in the spectrometer, data acquisition was limited to 17 seconds giving a sampling frequency of 0.06Hz.…”

“…A proof-of-concept study demonstrated the ability of a custom bNIRS system (SCISSCO) to quantify changes in HbO, HbR and oxCCO [ 41 ]. The oxCCO spectra used to quantify concentration changes was measured as part of the study by measuring the oxidized and reduced state of a prepared bovine heart.…”

“…They reported that the small observed change in oxCCO concentration indicates the absence of crosstalk as it does not mirror the hemoglobin signals. oxCCO has also been seen to remain constant despite a decrease in HbO during forearm occlusion using the SCISSCO system [ 41 ]. oxCCO and HbO were also observed to decrease during a finger occlusion in a single subject using the 4λ South Korea system [ 46 ].…”