## 7 Conclusions  
In summary, we developed a SCISCCO system that measures the changes in HbO, HbR, and the redox state of CCO simultaneously, and the instrument was used in pilot human and animal studies. The light source for the SCISCCO system was an all-fiber integrated modulational instability-initiated SCL that output up to 11 W of time-averaged power covering the NIR and SWIR wavelength range of 670-2500 nm. The CCO measurements were performed over 750-900 nm, the wavelength range over which the brightness of the SCL was almost an order of magnitude higher than a lamp or black body radiation source in our fiber-coupled configuration. This wavelength range covers much of the broad spectral absorption of CCO as well as the differing spectrum between HbR and HbO, and it is beyond where melanin absorbs light, so the measurements were substantially independent of skin color. High SNR measurements were achieved because of the SCL's high brightness, polarization filtering, a two-arm differential configuration to divide out SCL and environmental fluctuations, and the use of lock-in amplifiers to remove the effects from ambient light and other spurious signals. For use in hospital and lab settings at remote locations or for portability within a hospital, a cart-based SCISCCO prototype system was also assembled that integrates the hardware and software into a single portable instrument. The rolling cart system has three levels: the top level comprises the SCL and laptop for processing, the middle level comprises the optical system hardware, and the bottom level comprises the electronics  
Figure 36: (**a,b**) Two different swine measurements for pREBOA augmented with VPA. and lock-in amplifiers. A convenient GUI permits the user to input the measurement parameters and view the metabolic and hemodynamic data as a function of time. The stability of the cart-based prototype was verified by rolling the cart through buildings with brick flooring and driving in a van over local paved and dirt roads while measuring the spectral and power output as well as the balance between the sample and reference arms of the set-up. To validate the fidelity of the SCISCCO system, we conducted several experiments initially with laboratory mixtures or healthy participants. First, we measured CCO in vitro to confirm the NIR absorption spectrum for CCO. To demonstrate in vivo feasibility, the measured responses of oxygenation and CCO changes during the blood pressure tests in the human participants were compared to data from the literature. Furthermore, we showed that the hemodynamic response during the physiological breath-holding tests as well as the cognitive attention tests were comparable between the SCISCCO system and a commercial NIRS system. Next, we conducted a pilot human study of 25 participants using a cognitive attention test. The results showed that during the attention task, the level of HbO increased and the level of oxidized CCO decreased. The measured behavior was consistent with prior studies showing an increase in HbO in the frontal lobe during attention tasks and the interpretation of the CCO redox state as an indicator of cellular ATP demand and metabolism in the active brain region. Thus, our measurements provide a noninvasive, simultaneous measurement of both the cerebral hemodynamic response and metabolic demand using a noninvasive optical sensor. Finally, the cart-based SCISCCO prototype was transported to Northwestern University Medical Center and used in a series of swine animal tests aimed at controlling bleeding. In particular, the SCISCCO prototype was applied to swine animal models undergoing HS followed by pREBOA or pREBOA with VPA drug treatment. The data collected by the SCISCCO system were validated against other instruments, such as those used to measure arterial blood gases and the mean arterial pressure. In addition, the pilot animal studies established the feasibility of using the SCISCCO prototype within the context of existing protocols.