31 research outputs found

    Neural 360^\circ Structured Light with Learned Metasurfaces

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    Structured light has proven instrumental in 3D imaging, LiDAR, and holographic light projection. Metasurfaces, comprised of sub-wavelength-sized nanostructures, facilitate 180^\circ field-of-view (FoV) structured light, circumventing the restricted FoV inherent in traditional optics like diffractive optical elements. However, extant metasurface-facilitated structured light exhibits sub-optimal performance in downstream tasks, due to heuristic pattern designs such as periodic dots that do not consider the objectives of the end application. In this paper, we present neural 360^\circ structured light, driven by learned metasurfaces. We propose a differentiable framework, that encompasses a computationally-efficient 180^\circ wave propagation model and a task-specific reconstructor, and exploits both transmission and reflection channels of the metasurface. Leveraging a first-order optimizer within our differentiable framework, we optimize the metasurface design, thereby realizing neural 360^\circ structured light. We have utilized neural 360^\circ structured light for holographic light projection and 3D imaging. Specifically, we demonstrate the first 360^\circ light projection of complex patterns, enabled by our propagation model that can be computationally evaluated 50,000×\times faster than the Rayleigh-Sommerfeld propagation. For 3D imaging, we improve depth-estimation accuracy by 5.09×\times in RMSE compared to the heuristically-designed structured light. Neural 360^\circ structured light promises robust 360^\circ imaging and display for robotics, extended-reality systems, and human-computer interactions

    Factors associated with satisfaction with pediatric emergency department services in Korea: analysis of Korea Health Panel Data 2010 to 2012

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    Objective We aimed to investigate the factors related to satisfaction with the pediatric emergency department service in Korea. Methods This study examined data from the Korea Health Panel Data from 2010 to 2012. Pediatric patients who visited the emergency department at least once between 2010 and 2012 in Korea were included. Data were collected on patient satisfaction with the emergency department service, and factors related to the patient characteristics, emergency department service process, and medical institution. We compared the dissatisfied and satisfied groups, and calculated the odds ratios for satisfaction according to each variable. Results A total of 1,505 emergency department visits from 947 pediatric patients during the 3-year period were analyzed. We estimated that about 79.5% of patients in the population were satisfied. The odds of expressing satisfaction were higher among males than in females, and among patients who were hospitalized after emergency department treatment compared to those who were transferred to another hospital. Conversely, the odds of expressing satisfaction were lower among patients who had a chronic disease, a financial source other than National Health Insurance, experienced hospitalization within 1 year. Conclusion Our study results might be helpful for establishing a satisfactory pediatric emergency medical service system. In the future, further prospective studies evaluating the causal relationships between the relevant factors and patient satisfaction are warranted

    Use of smart glasses for ultrasound-guided peripheral venous access: a randomized controlled pilot study

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    Objective Smart glasses can provide sonographers with real-time ultrasound images. In the present study, we aimed to evaluate the utility of smart-glasses for ultrasound-guided peripheral venous access. Methods In this randomized, crossover-design, simulation study, 12 participants were recruited from the emergency department residents at a university hospital. Each participant attempted ultrasound-guided peripheral venous access on a pediatric phantom at intervals of 5 days with (glasses group) or without (non-glasses group) the use of smart glasses. In the glasses group, participants confirmed the ultrasound image through the lens of the smart glasses. In the non-glasses group, participants confirmed the ultrasound image through the display viewer located next to the phantom. Procedure time was regarded as the primary outcome, while secondary outcomes included the number of head movements for the participant, number of skin punctures, number of needle redirections, and subjective difficulty. Results No significant differences in procedural time were observed between the groups (non-glasses group: median time, 15.5 seconds; interquartile range [IQR], 10.3 to 27.3 seconds; glasses group: median time, 19.0 seconds; IQR, 14.3 to 39.3 seconds; P=0.58). The number of head movements was lower in the glasses group than in the non-glasses group (glasses group: median, 0; IQR, 0 to 0; non-glasses group: median, 4; IQR, 3 to 5; P<0.01). No significant differences in the number of skin punctures or needle restrictions were observed between the groups. Conclusion Our results indicate that smart-glasses may aid in ensuring ultrasound-guided peripheral venous access by reducing head movements

    PIV-MyoMonitor: an accessible particle image velocimetry-based software tool for advanced contractility assessment of cardiac organoids

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    Induced pluripotent stem cell (iPSC)-derived cardiac organoids offer a versatile platform for personalized cardiac toxicity assessment, drug screening, disease modeling, and regenerative therapies. While previous image-based contractility analysis techniques allowed the assessment of contractility of two-dimensional cardiac models, they face limitations, including encountering high noise levels when applied to three-dimensional organoid models and requiring expensive equipment. Additionally, they offer fewer functional parameters compared to commercial software. To address these challenges, we developed an open-source, particle image velocimetry-based software (PIV-MyoMonitor) and demonstrated its capacity for accurate contractility analysis in both two- and three-dimensional cardiac models using standard lab equipment. Comparisons with four other open-source software programs highlighted the capability of PIV-MyoMonitor for more comprehensive quantitative analysis, providing 22 functional parameters and enhanced video outputs. We showcased its applicability in drug screening by characterizing the response of cardiac organoids to a known isotropic drug, isoprenaline. In sum, PIV-MyoMonitor enables reliable contractility assessment across various cardiac models without costly equipment or software. We believe this software will benefit a broader scientific community

    Analysis of contact resistance in single-walled carbon nanotube channel and graphene electrodes in a thin film transistor

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    Abstract In this work, we present the experimental investigation on the contact resistance of graphene/single-walled carbon nanotube (SWCNT) junction using transfer length method with the simple equivalent circuit model. We find that p–n like junctions are formed in graphene/SWCNT transistors, and the contact resistance in the junction is observed to be ~ 494 and ~ 617 kΩ in case of metallic SWCNT (m-SWCNT) and semiconducting SWCNT (s-SWCNT), respectively. In addition, the contact resistance increases from 617 to 2316 kΩ as Vg increases from − 30 to − 10 V. Through our study, high carrier density induced from doping in both graphene and SWCNT leads to low contact resistance. This development of contact engineering, namely modulation of carrier density in the junction and contact length (Lcon) scaling shows the potential for all-carbon based electronics

    Clinical Characteristics and Therapeutic Outcomes of Pediatric Blepharokeratoconjunctivitis

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    Purpose:The purpose of this study was to determine the clinical characteristics, disease course, therapeutic outcomes, and prognostic factors for pediatric patients with blepharokeratoconjunctivitis (BKC).Methods:A retrospective medical chart review was performed for patients aged 15 years or younger who had been diagnosed with BKC between 2004 and 2020 at 2 tertiary hospitals in Korea. The following data were collected: demographics, medical history, ocular findings, geometric profiling of corneal lesion, medical management, and outcomes.Results:A total of 137 patients (90 female and 47 male) were included. The patients&apos; mean age was 8.3 ± 3.8 years at disease onset. Both eyes were involved in 57.7% of cases. The most common corneal lesion was corneal neovascularization (77.4%), followed by clinically visible corneal infiltration (51.8%) and stromal scarring (43.1%). Most of the corneal lesions involved a single quadrant, most commonly the inferior quadrant. After treatment, disease remission was achieved in 95% of patients, and visual acuities improved from 0.2 ± 0.3 logarithm of minimal angle of resolution at disease presentation to 0.1 ± 0.3 logarithm of minimal angle of resolution at final follow-up (P = 0.001). Recurrence occurred in 52.6% of patients. Cylinder power was significantly higher in patients with recurrence than in those without. The number of cases of recurrence was positively associated with final cylinder power.Conclusions:Although the treatment induced disease remission in 95% of children with BKC, recurrence occurred in 52.6% of those cases. Because recurrence resulted in significant astigmatism, careful observation for recurrence and prompt management are warranted for preservation of vision in pediatric patients with BKC.N

    The impact of preoperative kidney replacement therapy on kidney outcome and survival in patients with left ventricular assist device

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    AbstractLeft ventricular assist device (LVAD) has been highlighted as a new treatment option in the end-stage heart failure (HF). Kidney outcome after LVAD in severe cardiorenal syndrome (CRS) patients requiring kidney replacement therapy (KRT) is unclear. We investigated the impact of preoperative KRT on kidney function and survival in LVAD patients with severe CRS. A total of 50 patients followed up for at least 1 year after LVAD implantation was analyzed. The primary outcomes were estimated glomerular filtration rate and survival rate. Patients were divided into two groups depending on in-hospital KRT before LVAD implantation: the control group (n = 33) and the KRT group (n = 17). Postoperative KRT was performed for 76.5% of patients in the KRT group, and all of them discontinued KRT before discharge. There were no statistically significant differences in the degree of eGFR decline in survivors according to preoperative KRT. Although there were no statistically significant differences in the degree of eGFR decline in survivors regardless of preoperative KRT, old age (β −0.94, p < 0.01), preexisting chronic kidney disease (β −21.89, p < 0.01), and high serum creatinine (β −13.95, p < 0.01) were identified as independent predictors of post-LVAD eGFR decline. Mortality rate was higher, and more patients progressed to end-stage kidney disease in KRT group than control group. However, LVAD still can be considered as the treatment option in end-stage HF patients with severe CRS requiring KRT, especially in those with young age and previous normal kidney function

    The characteristics of pediatric emergency department visits in Korea: An observational study analyzing Korea Health Panel data.

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    OBJECTIVE:We investigated the characteristics of pediatric emergency department (ED) patients in Korea and determined factors associated with hospital admission after ED treatment. METHODS:Korea Health Panel data from 2008 through 2013 were analyzed retrospectively; we included patients under 18 years old who visited the ED at least once. We collected patient and household epidemiologic data such as sex, age group, region of residence, disability, chronic disease, household income quintile, national health insurance type, use of private insurance, and annual frequency of ED visits. We also examined data related to each ED visit, such as reason for visit, medical service provided, and hospital size/ownership. We then investigated which factors were correlated with case disposition (discharge home or hospital admission) after ED treatment. RESULTS:In total, 3,160 pediatric ED visits occurred during the six-year period. Males (57.5%) and children aged 0-5 years (47.7%) made more visits than females and older children, respectively. The proportion of ED visits for disease (67.7%) was much higher than for injury or poisoning (32.2%), and 452 cases (14.3%) required hospital admission. For hospital admission, the odds ratio (OR) of females was 0.73 compared to males, and the OR of children aged 6-11 was 0.68 compared to children aged 0-5. The OR of capital residents was 0.69 compared to province residents, and the OR of the highest income quintile was 0.51 compared to the lowest quintile. The OR of children with private insurance coverage was 0.49 compared to those lacking private insurance, and the OR of ED visits due to disease was 1.82 compared to visits due to injury/poisoning. CONCLUSION:This analysis of clinical and demographic characteristics of pediatric ED visits and hospital admissions can serve as the foundation of future prospective studies required for establishing appropriate policies for the Korean pediatric emergency medical system
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