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[This corrects the article DOI: 10.1117/1.JBO.27.10.106001.]., ImPhys/Computational Imaging, ImPhys/Rieger group

Objectives: To examine whether adolescents exceed recommended noise exposure limits when using personal listening devices (PLDs) and to investigate the relationship between objectively measured PLD use and hearing thresholds Study Design: Cross-sectional study. Setting: This study was embedded within an ongoing prospective birth cohort study in Rotterdam, the Netherlands. Data were collected from May 2017 to September 2019. Methods: A smartphone application was developed to measure daily noise exposure from PLDs. Listening habits were monitored among 314 adolescents with a mean age of 13 years 7 months (SD, 5 months), of whom 51.6% were male. Hearing acuity was measured by pure tone audiometry, and tympanometry was performed in both ears. Results: Within the study group, 2.2% adolescents exceeded the recommended daily noise dose (85 dBA as an 8-hour time-weighted average) among all days when the application was active and 9.9% when among only the listening days. No significant correlation was found between the daily noise dose from PLDs and pure tone thresholds. Conclusions: The majority of adolescents exhibited listening habits that could be considered safe. As noise-induced hearing loss develops slowly over time, it could be that the effects of PLD use on hearing are not evident yet in this young population with a relatively short duration of PLD use.

SignificanceFlexible endoscopes are essential for medical internal examinations. Digital endoscopes are connected to a video processor that can apply various operations to enhance the image. One of those operations is edge enhancement, which has a major impact on the perceived image quality by medical professionals. However, the specific methods and parameters of this operation are undisclosed and the arbitrary units to express the level of edge enhancement differ per video processor.AimObjectively quantify the level of edge enhancement from the recorded images alone, and measure the effect on sharpness and noise.ApproachEdge enhancement was studied in four types of flexible digital ear nose and throat endoscopes. Measurements were performed using slanted edges and gray patches. The level of edge enhancement was determined by subtracting the step response of an image without edge enhancement from images with selected settings of edge enhancement and measuring the resulting peak-to-peak differences. These values were then normalized by the step size. Sharpness was characterized by observing the normalized modulation transfer function (MTF) and computing the spatial frequency at 50% MTF. The noise was measured on the gray patches and computed as a weighted sum of variances from the luminance and two chrominance channels of the pixel values.ResultsThe measured levels were consistent with the level set via the user interface on the video processor and varied typically from 0 to 1.3. Both sharpness and noise increase with larger levels of edge enhancement with factors of 3 and 4 respectively.ConclusionsThe presented method overcomes the issue of vendors expressing the level of edge enhancement each differently in arbitrary units. This allows us to compare the effects, and we can start exploring the relationship with the subjectively perceived image quality by medical professionals to find substantiated optimal settings., ImPhys/Computational Imaging

Objectives: Coronavirus disease 2019 has put unprecedented pressure on healthcare systems worldwide, leading to a reduction of the available healthcare capacity. Our objective was to develop a decision model to estimate the impact of postponing semielective surgical procedures on health, to support prioritization of care from a utilitarian perspective. Methods: A cohort state-transition model was developed and applied to 43 semielective nonpediatric surgical procedures commonly performed in academic hospitals. Scenarios of delaying surgery from 2 weeks were compared with delaying up to 1 year and no surgery at all. Model parameters were based on registries, scientific literature, and the World Health Organization Global Burden of Disease study. For each surgical procedure, the model estimated the average expected disability-adjusted life-years (DALYs) per month of delay. Results: Given the best available evidence, the 2 surgical procedures associated with most DALYs owing to delay were bypass surgery for Fontaine III/IV peripheral arterial disease (0.23 DALY/month, 95% confidence interval [CI]: 0.13-0.36) and transaortic valve implantation (0.15 DALY/month, 95% CI: 0.09-0.24). The 2 surgical procedures with the least DALYs were placing a shunt for dialysis (0.01, 95% CI: 0.005-0.01) and thyroid carcinoma resection (0.01, 95% CI: 0.01-0.02). Conclusion: Expected health loss owing to surgical delay can be objectively calculated with our decision model based on best available evidence, which can guide prioritization of surgical procedures to minimize population health loss in times of scarcity. The model results should be placed in the context of different ethical perspectives and combined with capacity management tools to facilitate large-scale implementation.