Patterns in the Pandemic: Disproportionate Patient Burdens Among Regional Hospitals.

STUDY OBJECTIVE: To examine the distribution of hospitalized COVID-19 patients among adult acute care facilities in the Greater Philadelphia area and identify factors associated with hospitals carrying higher burdens of COVID-19 patients. METHODS: In this observational descriptive study, we obtained self-reported daily COVID-19 inpatient censuses from 28 large (>100 beds) adult acute care hospitals in the Greater Philadelphia region during the initial wave of the COVID-19 pandemic (March 23, 2020, to July 28, 2020). We examined hospitals based on their size, location, trauma certification, median household income, and reliance on public insurance. COVID-19 inpatient burdens (ie, beds occupied by COVID-19 patients), relative to overall facility capacity (ie, total beds), were reported and assessed using thresholds established by the Institute of Health Metrics and Evaluation to approximate the stress induced by different COVID-19 levels. RESULTS: Maximum (ie, peak) daily COVID-19 occupancy averaged 27.5% (SD 11.2%) across the 28 hospitals. However, there was dramatic variation between hospitals, with maximum daily COVID-19 occupancy ranging from 5.7% to 50.0%. Smaller hospitals remained above 20% COVID-19 capacity for longer (small hospital median 27.5 days [interquartile range {IQR}: 4 to 32]; medium hospital median 18.5 days [IQR: 0.5 to 37]; large hospital median 13 days [IQR: 6 to 32]). Trauma centers reached 20% capacity sooner (median 19 days [IQR: 16-25] versus nontrauma median 30 days [IQR: 20 to 128]), remained above 20% capacity for longer (median 31 days [IQR: 11 to 38]; nontrauma median 8 days [IQR: 0 to 30]), and had higher observed burdens relative to their total capacity (median 5.8% [IQR: 2.4% to 8.3%]; nontrauma median 2.5% [IQR: 1.6% to 2.8%]). Urban location was also predictive of higher COVID-19 patient burden (urban median 3.8% [IQR: 2.6% to 6.7%]; suburban median 2.2% [IQR: 1.5% to 2.8%]). Heat map analyses demonstrated that hospitals in lower-income areas and hospitals in areas of higher reliance on public insurance also exhibited substantially higher COVID-19 occupancy and longer periods of higher COVID-19 occupancy. CONCLUSION: Substantial discrepancies in COVID-19 inpatient burdens existed among Philadelphia-region adult acute care facilities during the initial COVID-19 surge. Trauma center status, urban location, low household income, and high reliance on public insurance were associated with both higher COVID-19 burdens and longer periods of high occupancy. Improved data collection and centralized sharing of pandemic-specific data between health care facilities may improve resource balancing and patient care during current and future response efforts.

A Guided Wave Inspection Technique for Wedge Features.

Numerous engineering components feature prismatic wedge-like structures that require nondestructive evaluation (NDE) in order to ensure functionality or safety. This article focuses on the inspection of the wedge-like seal fins of a jet engine drum, though the capabilities presented will be generic. It is proposed that antisymmetric flexural edge modes, feature-guided waves localized to the wedge tips, may be used for defect detection. Although analytical solutions exist that characterize the ultrasonic behavior of ideal wedges, in practice, real wedges will be irregular (containing, for example, truncated tips that are built onto an associated structure or have nonstraight edges), and therefore, generic methodologies are required to characterize wave behavior in nonideal wedges. This article uses a semianalytical finite-element (SAFE) methodology to characterize the guided waves in wedge-like features with irregular cross sections to assess their suitability for NDE inspection and compare them with edge modes in ideal wedges. The science and methodologies required in this article are necessary to select an appropriate operating frequency for the particular application at hand. In addition, this article addresses the practical challenge of excitation and detection of flexural edge modes by presenting a piezoelectric-based dry-coupled transducer system suitable for pulse-echo operation. This article, therefore, presents the scientific basis required for industrial exploitation, together with the practical tools that facilitate use. The study concludes with the experimental demonstration of the edge wave-based inspection of a seal fin, achieving a signal-to-noise ratio of 28 dB from a 0.75-mm radial tip defect.

Rate-based structural health monitoring using permanently installed sensors.

Permanently installed sensors are becoming increasingly ubiquitous, facilitating very frequent in situ measurements and consequently improved monitoring of 'trends' in the observed system behaviour. It is proposed that this newly available data may be used to provide prior warning and forecasting of critical events, particularly system failure. Numerous damage mechanisms are examples of positive feedback; they are 'self-accelerating' with an increasing rate of damage towards failure. The positive feedback leads to a common time-response behaviour which may be described by an empirical relation allowing prediction of the time to criticality. This study focuses on Structural Health Monitoring of engineering components; failure times are projected well in advance of failure for fatigue, creep crack growth and volumetric creep damage experiments. The proposed methodology provides a widely applicable framework for using newly available near-continuous data from permanently installed sensors to predict time until failure in a range of application areas including engineering, geophysics and medicine.

Evaluation of the NAL-NL1 and DSL v4.1 prescriptions for children: Preference in real world use.

This paper reports real world preferences of children in a double-blind, cross-over trial comparing NAL-NL1 and DSL v.4.1 prescriptions. Twenty-four children wore digital WDRC hearing aids at each site (Australia, Canada). Multi-memory hearing aids provided the NAL and DSL programs in each of two memories. Diaries were completed during two counterbalanced trials, providing overall preference, situational preference, and preference comments. Ratings were reliable, and situational preferences factored into quiet/low level situations versus noisy/reverberant/high level situations. Children at both sites used DSL v4.1 for hearing low level speech, or when they wanted to hear loudly and clearly. Children used NAL-NL1 when they wished to hear sounds at a lower level, or to reduce background noise. Children expressed strong preferences for having the choice of both programs. Canadian children were more likely to prefer DSL than were the Australian children. Factors such as listening environment and prior listening experience are discussed in interpreting these findings.