Simulation Technologies (United States)

Intermittent mandatory ventilation (IMV) has evolved substantially from its original form, developing into 5 distinct types intended to enhance patient safety, comfort, and liberation from mechanical ventilation. Each form of IMV has different potential advantages and disadvantages that should be considered when selecting the mode of ventilation. IMV(1): the set mandatory breath rate is always delivered. IMV(2): mandatory breaths may be suppressed by spontaneous breaths if their frequency is high enough. IMV(3): mandatory breaths may be suppressed by spontaneous breaths if they achieve some pre-set goal (eg, minute ventilation threshold). IMV(4): individual mandatory breaths may be suppressed if inspiratory effort is high enough to change volume cycling into flow cycling for patient-triggered breaths. IMV(5): in Pressure Support, individual mandatory breaths are suppressed if the flow cycle threshold is met after the Ti-min setting has elapsed. This article offers a comprehensive review of the definitions and characteristics of these 5 IMV types, providing guidance on their identification based on information from ventilator manufacturers' information and by examining the actual ventilator waveforms produced by ventilating a high-fidelity lung simulator. The purpose is to clarify how the breath sequences called IMV are implemented in current ventilators and to build the reader's skill in identifying them. This skill is essential for clinical application, education, and research in mechanical ventilation. Ultimately, the goal is to improve the knowledge and application of IMV in clinical practice education and research.

Antisense oligonucleotide (ASO) therapeutics present new opportunities for treating challenging-to-treat diseases. Prediction of concentration-time course in systemic circulation and tissues within the context of large molecule physiologically based pharmacokinetic (PBPK) modelling has proven to be useful in animal-to-human extrapolation and first-in-human dose selection. A human PBPK model was developed and verified using bepirovirsen clinical data to predict plasma pharmacokinetics (PK) and tissue concentrations. Liver and kidney partition coefficient ratios from monkey studies, corrected for plasma unbound fraction in monkeys and humans, informed bepirovirsen concentration predictions in the human liver and kidney. Liver and kidney partition coefficients were calculated to be 2147 and 2822, respectively. All predicted PK parameters in healthy volunteers (except tmax) were within two-folds of observed data. Predicted vs. observed clearance (L/h), AUC0-inf (µg.h/mL) and Cmax (µg/mL) for the 300 mg single dose in healthy volunteers were 2.94, 114.43, and 10.56 vs. 2.25, 136.6, and 6.5, respectively. The majority of observed plasma concentrations for all doses were within the 5th and 95th percentiles of the predictions. The evaluated model was used to predict the impact of moderate hepatic impairment on bepirovirsen PK in virtual patients. The predicted vs. observed bepirovirsen exposure in moderate hepatic impairment was 0.9 and 0.7-fold lower, respectively, compared with healthy volunteers. The PBPK model predicted the liver and kidney tissue Cmax values to be 172 and 132 µg/mL, respectively. In conclusion, a PBPK modelling approach for bepirovirsen, an ASO, is presented in this article and offers opportunities for future applications to other oligonucleotide therapeutics.

Introduction: Augmented reality (AR) offers an immersive experience by overlaying digital content onto the real world, creating a more realistic and three-dimensional environment for users. We hypothesized that AR technology would improve live procedural performance of trainees. This study aimed to demonstrate the utility of AR in assisting resident and fellow ultrasound-guided central line simulation training. Methods: This was a prospective observational study. Physician trainees participating in residency and fellowship programs at the University of Alabama at Birmingham were recruited for this study. Participants received brief training on ultrasound-guided vascular access and use of AR. All participants performed vascular access with and without AR assistance. A Microsoft HoloLens 2 AR headset equipped with the HoloUS application was used to display real-time ultrasound imaging to the user. Our primary outcomes include: the number of needle sticks, head redirections and total time required for successful vascular access. We also surveyed the participants about their experience using AR and their preferences for the use of this technology in the future. Results: Fifty-one physician trainees participated in the study. All participants were successfully able to obtain vascular access on each attempt. There was no significant difference between groups in the time (30.06 seconds versus 29.96 seconds; p 0.0803) or number of needle sticks (1.18 versus 1.25; p 0.5391). However, there was a significant reduction in the average number of head redirections (2.96 versus 5.26, mean difference -2.31; 95% CI: -4.42 to -2.02; p 0.033) required with the use of AR. Results from survey data showed a preference toward the use of AR in performing vascular access, with 51% of participants favoring AR assistance, and 25% reporting no difference. Also, 76% of participants indicated they would opt to use AR technology to assist with vascular access if it were available to them. Conclusions: AR is a feasible tool in vascular access training. It is non-inferior to ultrasound guidance alone in total time spent and number of needle sticks and superior with fewer head turns in obtaining vascular access.

Introduction: Delivering challenging news is an important but often daunting part of pediatric residency. Simulation-based education has been proven to be an effective method to teach this vital communication skill. There is evidence that pediatric residents report increased confidence in communication skills after participating in communication education with a simulation component. The aim of this study is to compare retention of communication skills over a 3-6 month time period between two common simulation modalities: traditional vs rapid cycle deliberate practice (RCDP). Methods: Participants will include Pediatric, Pediatric Genetics, Pediatric Neurology, and Medicine Pediatric Residents during their PICU rotation. Participants will receive a chalk talk on the importance of three key communication skills. These skills include: use of a headline statement, use of NURSE statements in response to emotion, and therapeutic silence. Following this education, they will individually participate in a simulation case designed to be appropriate to the level of training and broad enough to be applicable to all pediatrics residents. The case involves delivering the news to a single mother that her infant has bacterial meningitis. A specifically communication-trained standardized patient will be used and participants will be split into a RCDP group and a traditional simulation group. In the 3-6 months following the initial simulation, each participant will participate in a follow-up traditional simulation to evaluate skills retention using a Likert scale. The encounter will be recorded and reviewed by the lead investigator and an independent reviewer. Participant self-evaluation and perceived usefulness of the simulation will also be collected at both time points. Results: As this study is ongoing, results are currently pending. The follow-up simulation cases will begin in August 2025 as all participants have been enrolled. A total of 20 residents completed the didactic session and initial simulation. Follow up simulation cases will be complete by January 2026. Conclusions: Preliminary findings from the initial phase suggest that residents find didactic lecture followed by simulation to be a useful learning strategy. Participants particularly appreciate the real-time feedback associated with RCDP simulation.

Large polycyclic aromatic hydrocarbon (PAH) imides are promising candidates for optoelectronic applications in view of their narrow optical gaps and/or excited state charge transfer character. Diels–Alder (D–A) reactions of PAHs at bay regions can enable simultaneous extension of the aromatic structure and introduction of the imide moieties, but the actual use of this strategy has been limited. Herein, we demonstrate the D–A cycloaddition of dibenzo[hi,st]ovalene, one of the largest PAHs functioning as bisdiene, with maleimides to afford circumpyrene tetracarboxydiimides. Notably, efforts to optimize the yield of di-adduct revealed that the fully aromatized mono-adduct is inert toward further D–A reaction, and density functional theory (DFT) calculations instead indicated a partially dehydrogenated mono-adduct as the key intermediate enabling the second cycloaddition. The resulting product represents a rare example of PAH diimide featuring an acceptor-donor-acceptor type structure. Detailed spectroscopic and theoretical studies, including transient absorption and two-dimensional electronic spectroscopy, revealed the emergence of a bright intramolecular charge transfer state that could be directly excited to demonstrate distinct photophysical dynamics. These findings provide deep mechanistic insights into the D–A reactivity of large PAHs and underscores the potential of such PAH imides for advanced optoelectronic and photonic applications.

ABSTRACTThe rational design of heterostructured photocatalysts that simultaneously enable efficient carrier separation, photothermal synergy, and controllable reaction pathways is crucial for advancing CO2 conversion. Here, a Ni/Ti3C2Clx MXene heterojunction is synthesized via Lewis acid molten‐salt etching, featuring ultrathin Ni platelets strongly anchored to the MXene substrate through interfacial TiNi3 bonding. This architecture establishes an S‐scheme charge transfer pathway, as evidenced by in situ irradiated X‐ray photoelectron and X‐ray absorption spectroscopy, which confirm efficient carrier transfer and separation, while femtosecond transient absorption spectroscopy reveals ultrafast interfacial dynamics. Under photothermal conditions, the cooperative interplay of metallic Ni, surface NiOx, and the conductive MXene substrate couples directional charge migration with thermally assisted molecular activation and barrier lowering, thereby enabling regulated CO2 hydrogenation product distribution between CH4 and CH3OH. Density functional theory demonstrates that surface‐state evolution, rather than simple oxidation degree, modulates adsorption energetics and alters the relative barriers of CH4 and CH3OH pathways, such that moderately oxidized Ni–NiOx interfacial ensembles favour methanol forming intermediates, whereas extensive oxidation suppresses CH3OH formation. Collectively, these findings demonstrate a robust strategy for exploiting MXene‐based heterojunction interfaces in photothermal catalysis and underscore the pivotal role of surface state regulated reaction pathways in steering product distribution during CO2 hydrogenation.

Video conferencing has become an integral part of everyday communication. However, users often lose awareness of their active webcams during online meetings, resulting in inadvertent privacy leakage. Existing webcam indicators, such as LED lights and software icons, demand constant user vigilance, which becomes impractical and ineffective during long online meetings. Our survey with 85 participants confirms the insufficiency of current webcam privacy mechanisms. To address this security gap, we propose a robotic desktop assistant that communicates camera activity through subtle physical motion, turning toward the user to mimic natural eye contact. The core concept is to leverage humans’ innate sensitivity to environmental motion for intuitive human-camera interaction, eliminating the need for users to consciously look at the camera to check its status. We implement the robotic desktop assistant concept based on Raspberry Pi and a servo-mounted webcam. When the webcam is on, the system operates a closed-loop controller that tracks user motion using a lightweight computer vision model and adjusts its pan-tilt angles in real time to mimic human-like eye contact. The loop latency is less than 45ms. The system can be deployed both as a peripheral webcam or an independent assistant. Experimental results and user studies show that the motion-based cues significantly improve users’ awareness of webcam activity without distraction or adding to user workload. The prototype system can be further enhanced by integrating voice control, large language models, and a laser projection module, transforming it into a fully functional, standalone online meeting system, like your intelligent desktop companion.

Coherent vortical structures are an important feature of near-wall turbulence, and understanding how particles and bubbles move with respect to these structures can be useful for many applications of measurement and flow control. While many studies have characterized bubbles and particles in terms of preferential concentration within turbulent flows, few studies have examined this relationship within the context of targeting near-wall vortices for flow control applications. The current study examines the entrapment of bubbles and particles by these near-wall turbulent vortices by simulating 106 small bubbles and heavy particles in a turbulent channel flow using a one-way coupled point particle approximation with direct numerical simulations for Reynolds numbers up to Reτ=395. Their entrapment relative to tracer particles shows a clear preference for bubbles to move into vortex cores and heavy particles to move away from vortex cores, and special limiting flow cases demonstrate the effect of flow time scales on overall entrapment. Our findings suggest that the entrapment (or lack thereof) saturates on a time scale of t+≈100 across all simulated Reynolds numbers for both particles and bubbles, and we show that bubble entrapment is limited by the lifetimes of local structures in near-wall turbulence. Therefore, the current work provides a characterization of an important constraint for potential particle-based flow control strategies.