Compact and cost-effective laser-powered speckle contrast optical spectroscopy fiber-free device for measuring cerebral blood flow.

Significance: In the realm of cerebrovascular monitoring, primary metrics typically include blood pressure, which influences cerebral blood flow (CBF) and is contingent upon vessel radius. Measuring CBF noninvasively poses a persistent challenge, primarily attributed to the difficulty of accessing and obtaining signal from the brain. Aim: Our study aims to introduce a compact speckle contrast optical spectroscopy device for noninvasive CBF measurements at long source-to-detector distances, offering cost-effectiveness, and scalability while tracking blood flow (BF) with remarkable sensitivity and temporal resolution. Approach: The wearable sensor module consists solely of a laser diode and a board camera. It can be easily placed on a subject's head to measure BF at a sampling rate of 80 Hz. Results: Compared to the single-fiber-based version, the proposed device achieved a signal gain of about 70 times, showed superior stability, reproducibility, and signal-to-noise ratio for measuring BF at long source-to-detector distances. The device can be distributed in multiple configurations around the head. Conclusions: Given its cost-effectiveness, scalability, and simplicity, this laser-centric tool offers significant potential in advancing noninvasive cerebral monitoring technologies.

A compact and cost-effective laser-powered speckle visibility spectroscopy (SVS) device for measuring cerebral blood flow.

In the realm of cerebrovascular monitoring, primary metrics typically include blood pressure, which influences cerebral blood flow (CBF) and is contingent upon vessel radius. Measuring CBF non-invasively poses a persistent challenge, primarily attributed to the difficulty of accessing and obtaining signal from the brain. This study aims to introduce a compact speckle visibility spectroscopy (SVS) device designed for non-invasive CBF measurements, offering cost-effectiveness and scalability while tracking CBF with remarkable sensitivity and temporal resolution. The wearable hardware has a modular design approach consisting solely of a laser diode as the source and a meticulously selected board camera as the detector. They both can be easily placed on a subject's head to measure CBF with no additional optical elements. The SVS device can achieve a sampling rate of 80 Hz with minimal susceptibility to external disturbances. The device also achieves better SNR compared with traditional fiber-based SVS devices, capturing about 70 times more signal and showing superior stability and reproducibility. It is designed to be paired and distributed in multiple configurations around the head, and measure signals that exceed the quality of prior optical CBF measurement techniques. Given its cost-effectiveness, scalability, and simplicity, this laser-centric tool offers significant potential in advancing non-invasive cerebral monitoring technologies.

A Review of COVID-19's Impact on Radiology Residents' Academics and Wellness in North America.

BACKGROUND: The COVID-19 pandemic caused major disruptions in radiology departments throughout North America. Radiology residency programs were forced to make dramatic changes to their training programs, which had major impacts on resident academics and wellness. The goal of this review is to evaluate the impact of COVID-19 on radiology residents' academics and wellness in North America, while also identifying effective measures taken by programs to mitigate the effects of the pandemic. METHODS: The search strategy involved database search via PubMed, Embase, and Web of Science with specific key words related to COVID-19, radiology residents, education, wellness, and virtual learning. Studies discussing the education and wellness of radiology residents in North America published after 2020 were included. The data were analyzed using a narrative synthesis approach. RESULTS: The three main domains affected by the pandemic include the residency curriculum, research, and resident wellness. The decline in case volume and diversity of cases had negative overall impact on education of radiology residents, but simulated cases and virtual learning proved its value during the pandemic and may have lasting implications for the postpandemic world. Research initiatives transitioned to a remote format with greater emphasis on quality improvement and COVID-19-related studies. Reduced face-to-face interaction opportunities made it difficult to establish strong and meaningful interpersonal connections and had a negative impact on resident wellness, mentorship, and professional development. Implementing mentorship programs and virtual "town hall meetings" were effective measures to maintain connections during times of social distancing. Finally, the COVID-19 pandemic introduced unprecedented stressors and challenges for radiology residents that negatively impacted their mental health and wellness. Incorporating wellness initiatives such as wellness hours and team-building activities and using social media were helpful in promoting wellness and mental health for radiology residents. CONCLUSION: The COVID-19 pandemic has had a significant impact on the academics and wellness of radiology residents across North America but has taught us many lessons that can help us navigate the ongoing challenges of the pandemic, the postpandemic world, and future pandemics.