Background: Minimally invasive surgical techniques, including laparoscopic and robotic surgery, have profoundly impacted surgical practice by improving precision, reducing recovery times, and minimizing complications. However, these modalities differ in their cognitive demands and skill acquisition requirements, which can influence the learning curve and operative performance. To assess and evaluate this variability across these modalities, a functional near-infrared spectroscopy (fNIRS) system is used as an objective method for monitoring cognitive activity in surgical trainees. fNIRS can provide insights and further our understanding of the mental demands of different surgical techniques and their association with varying task complexity. Objective: This study seeks to assess the influence of surgical modality (laparoscopy vs. robotic surgery) and task complexity (pick and place (PP) vs. knot tying (KT)) on cognitive workload through fNIRS. We compare real-world and simulation-based training environments to determine changes in brain activation patterns and task performance. Methods: A total of twenty-six surgical trainees (general and gynecologic surgery residents and specialists) participated in this study. Participants completed standardized laparoscopic and robotic surgical tasks at varying levels of complexity while their cognitive workload was measured using fNIRS. This study included both simulation-based training and real-world surgical environments. Hemodynamic responses in the prefrontal cortex (PFC), task completion times, and performance metrics were analyzed. Results: Laparoscopic surgery elicited higher activity changes in the prefrontal cortex, indicating increased cognitive demand compared with robotic surgery, particularly for complex tasks like knot tying. Task complexity significantly influenced mental load, with more intricate procedures eliciting greater neural activation. Real-world training resulted in higher cognitive engagement than simulation, emphasizing the gap between simulated and actual surgical performance. Conclusions: Cognitive workload was lower and significantly different during robotic surgery than during laparoscopy, potentially due to its ergonomic advantages and enhanced motor control. Simulation-based training effectively prepares surgeons, but the cognitive workload results indicate that it may not fully replicate real-world surgical environments. These findings reveal the importance of cognitive workload assessment in surgical education and suggest that incorporating neuroimaging techniques such as fNIRS into training programs could enhance skill acquisition and performance.

Achieving simultaneous cerebral blood flow (CBF) and oxygenation measures, specifically for point-of-care injury monitoring in prolonged field care, requires the implementation of appropriate methodologies and advanced medical device design, development, and evaluation. The near-infrared spectroscopy (NIRS) method measures the absorbance of light whose attenuation is related to cerebral blood volume and oxygenation. By contrast, diffuse correlation spectroscopy (DCS) allows continuous noninvasive monitoring of microvascular blood flow by directly measuring the degree of light scattering because of red blood cell (RBC) movement in tissue capillaries. Hence, this study utilizes these two optical approaches (DCS–NIRS) to obtain a more complete hemodynamic monitoring by providing cerebral microvascular blood flow, hemoglobin oxygenation and deoxygenation in hemorrhage, and hypoxia-induced injuries. Piglet models of hemorrhage and hypoxia-induced brain injury were used with DCS and NIRS sensors placed over the preorbital to temporal skull regions. To induce hemorrhagic shock, up to 70% of the animal’s total blood volume was withdrawn through graded hemorrhage serially via a syringe from a femoral artery cannula in 10 mL/kg aliquots over 1 minute every 10 minutes. A second group of animals was subjected to hypoxia for ∼1 hour through graded hypoxia by serial titration from normoxic fraction inspired oxygen of 21% to hypoxic fraction inspired oxygen of 6%. A subset of animals served as sham-controls undergoing anesthesia, instrumentation, and ventilation as the injury groups, yet experiencing no blood loss or hypoxia. We first investigated the relationship between hemorrhagic shock and no shock by using measured biomarkers, including blood flow index from DCS associated with CBF and oxygenated (HbO) and de-oxygenated hemoglobin from NIRS. The statistical analysis revealed a significant difference between no shock and hemorrhagic shock (P < .01). The HbO decreased with each blood loss as expected, yet the de-oxygenated hemoglobin was slightly changed. During hypoxia-induced global hypoxic–ischemic injury tests, the CBF results from graded hypoxia were consistent with the response previously measured during hemorrhagic shock. Moreover, HbO decreased when the animal was hypoxic, as expected. A statistical analysis was also conducted to compare the results with those of the sham controls. There is a consistency in blood flow measures in both injury mechanisms (hemorrhagic shock and hypoxia), which is significant as the new prototype system provides similar measures and trends for each brain injury type, suggesting that the optical system can be used in response to different injury mechanisms. Notably, the results support the idea that this optical system can probe the hemodynamic status of local cerebral cortical tissue and provide insight into the underlying changes of cerebral tissue perfusion at the microvascular level. These measurement capabilities can improve shock identification and monitoring of medical management of injuries, particularly hemorrhagic shock, in prolonged field care.

Background: Reliable intraoperative monitoring of anesthesia depth is critical for patient safety, yet standard monitors can be confounded by systemic physiological changes. Non-invasive optical modalities that measure cerebral hemodynamics offer a promising approach, but their ability to differentiate brain neurovascular activity assessment versus changes due to systemic events requires validation. This study aims to explore the robustness of diffuse correlation (DCS) and near-infrared spectroscopy (NIRS) measures in differentiating changes in cerebral signals due to changes in anesthetic depth versus those resulting from alterations in systemic hemodynamics. Methods: A neonatal piglet model (N = 18) was used to assess anesthesia states and injury models creating systemic hemodynamic changes which may lead to instability in readings of hemodynamic responses and likely cause failure to detect the true anesthesia state. We continuously measured relative cerebral blood flow (rBFI), oxyhemoglobin (HbO), deoxyhemoglobin (HbR), and total hemoglobin (HbTotal) concentrations during three distinct conditions: (1) transition from deep to light anesthesia state in healthy piglets, (2) controlled hemorrhage, and (3) hypoxia induced under maintained deep anesthesia. Linear mixed-effects models were used to compare hemodynamic signatures across conditions. Results: Transition to light anesthesia was characterized by significant increases in rBFI (p.adj < 0.01), HbO (p.adj < 0.01), and HbTotal (p.adj < 0.05). Interaction analyses confirmed this distinct cerebral hemodynamic pattern was statistically different from the patterns of hemorrhagic shock (decreased rBFI, HbO, HbTotal) and hypoxic shock (decreased rBFI, HbO; increased HbR, HbTotal), with significant differences in trends (p.adj < 0.05). Optical biomarkers distinguished the transition to lighter anesthesia from early physiological changes during systemic insults, suggesting discriminative capability beyond severe shock states. Conclusions: These findings demonstrate that a DCS-NIRS system provides quantitative biomarkers capable of distinguishing changes in anesthetic depth from specific, controlled systemic insults causing subtle to severe hemodynamic instability, supporting its potential as a robust tool for improving intraoperative monitoring and patient safety.

Basic Life Support (BLS) is a crucial life-saving skill, and the effectiveness of different training methods for acquiring and transferring BLS knowledge and skills remains an important area of investigation. Traditional methods, such as lectures, may be less engaging and lack the practical application necessary for optimal skill transfer. New training modalities, including serious games on tablets and in virtual reality (VR) environments, offer interactive experiences, enable personalized feedback, and repetitive practice, potentially enhancing the learning process. However, the effectiveness of these newer training delivery methods on skill acquisition, transfer, and the underlying neurophysiological mechanisms needs further investigation. Hence, this study explores the effectiveness of various BLS training modalities, including traditional lecture-based instruction, tablet-based serious gaming, and VR-based serious gaming. A wearable functional near-infrared spectroscopy (fNIRS) sensory system is used to monitor prefrontal cortex (PFC) activity during training and subsequent hands-on testing. A total of 51 participants, who were randomly assigned to one of three training groups (lecture, tablet, VR), were analyzed. These participants underwent fNIRS monitoring during the training sessions and a final hands-on exam. Our findings revealed that while all three training modalities led to comparable hands-on exam performance, there were notable differences in neural activation patterns. VR-based training appeared to elicit neural responses indicative of more efficient use of cognitive resources during the hands-on test, suggesting its potential effectiveness as a practice mode for skill acquisition and transfer. These findings highlight the importance of considering both behavioral and neurophysiological metrics when assessing the efficacy of educational interventions.