Simultaneous patient presentation for endovascular thrombectomy in acute ischemic stroke

2019 ◽  
Vol 11 (12) ◽  
pp. 1201-1204 ◽  
Author(s):  
Ankur K Dalsania ◽  
Akash P Kansagra
Keyword(s):  
Time Series ◽  
Simultaneous Presentation ◽  
Time Of Day ◽  
Excess Demand ◽  
Patient Volume ◽  
Endovascular Thrombectomy ◽  
Empirical Distributions ◽  
Case Duration ◽  
Time Critical ◽  
Patient Presentation

BackgroundIncreased demand for endovascular thrombectomy has increased the likelihood of simultaneous patient presentation leading to competing demand for time-critical treatment that could adversely impact patient outcomes. We aimed to quantify the occurrence of simultaneous patient presentation at different patient volumes.MethodsEmpirical distributions for time of patient presentation and case duration were used to probabilistically generate arrival time and case duration for a set annual patient volume, ranging from 1 to 500 cases per year, for 16 000 independent trials at each volume. Time series were generated for each trial to represent the number of cases being performed at each minute of the year. Time series were used to calculate daily thrombectomy demand, annual concurrent demand, and hourly excess demand.ResultsThe patient volumes at which at least one annual occurrence of concurrent demand by two patients was 50% and 97.5% likely were 45 and 101, respectively. The volumes at which at least one annual occurrence of concurrent demand by three patients was 50% and 97.5% likely were 216 and 387, respectively. There was dramatic variation in the occurrence of excess demand by two or more patients throughout the day.ConclusionsThe occurrence of simultaneous presentation by multiple patients for endovascular thrombectomy varies with annual patient volume and time of day. Understanding these trends and the associated patient impact can inform intelligent strategies at regional and national levels for optimizing patient care within real-world financial and operational constraints.

scholarly journals A stacked dense denoising–segmentation network for undersampled tomograms and knowledge transfer using synthetic tomograms

2021 ◽  
Vol 32 (3) ◽  
Author(s):  
Dimitrios Bellos ◽  
Mark Basham ◽  
Tony Pridmore ◽  
Andrew P. French
Keyword(s):  
Time Series ◽  
Knowledge Transfer ◽  
Semantic Segmentation ◽  
Real World Data ◽  
Transfer Scheme ◽  
X Ray ◽  
Segmentation Accuracy ◽  
X Ray Computed ◽  
Temporal Events ◽  
Time Critical

AbstractOver recent years, many approaches have been proposed for the denoising or semantic segmentation of X-ray computed tomography (CT) scans. In most cases, high-quality CT reconstructions are used; however, such reconstructions are not always available. When the X-ray exposure time has to be limited, undersampled tomograms (in terms of their component projections) are attained. This low number of projections offers low-quality reconstructions that are difficult to segment. Here, we consider CT time-series (i.e. 4D data), where the limited time for capturing fast-occurring temporal events results in the time-series tomograms being necessarily undersampled. Fortunately, in these collections, it is common practice to obtain representative highly sampled tomograms before or after the time-critical portion of the experiment. In this paper, we propose an end-to-end network that can learn to denoise and segment the time-series’ undersampled CTs, by training with the earlier highly sampled representative CTs. Our single network can offer two desired outputs while only training once, with the denoised output improving the accuracy of the final segmentation. Our method is able to outperform state-of-the-art methods in the task of semantic segmentation and offer comparable results in regard to denoising. Additionally, we propose a knowledge transfer scheme using synthetic tomograms. This not only allows accurate segmentation and denoising using less real-world data, but also increases segmentation accuracy. Finally, we make our datasets, as well as the code, publicly available.

Exploring the dynamic contribution behavior of editors in wikis based on time series analysis

2016 ◽  
Vol 50 (1) ◽  
pp. 41-57 ◽  
Author(s):  
Linghe Huang ◽  
Qinghua Zhu ◽  
Jia Tina Du ◽  
Baozhen Lee
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Time Series Data ◽  
Time Of Day ◽  
Observation Time ◽  
Series Data ◽  
Clustering Methods ◽  
Content Type ◽  
Free Rider Problem ◽  
Series Analysis

Purpose – Wiki is a new form of information production and organization, which has become one of the most important knowledge resources. In recent years, with the increase of users in wikis, “free rider problem” has been serious. In order to motivate editors to contribute more to a wiki system, it is important to fully understand their contribution behavior. The purpose of this paper is to explore the law of dynamic contribution behavior of editors in wikis. Design/methodology/approach – After developing a dynamic model of contribution behavior, the authors employed both the metrological and clustering methods to process the time series data. The experimental data were collected from Baidu Baike, a renowned Chinese wiki system similar to Wikipedia. Findings – There are four categories of editors: “testers,” “dropouts,” “delayers” and “stickers.” Testers, who contribute the least content and stop contributing rapidly after editing a few articles. After editing a large amount of content, dropouts stop contributing completely. Delayers are the editors who do not stop contributing during the observation time, but they may stop contributing in the near future. Stickers, who keep contributing and edit the most content, are the core editors. In addition, there are significant time-of-day and holiday effects on the number of editors’ contributions. Originality/value – By using the method of time series analysis, some new characteristics of editors and editor types were found. Compared with the former studies, this research also had a larger sample. Therefore, the results are more scientific and representative and can help managers to better optimize the wiki systems and formulate incentive strategies for editors.

scholarly journals Assessing the Performance of Methods for Monitoring Ice Phenology of the World’s Largest High Arctic Lake Using High-Density Time Series Analysis of Sentinel-1 Data

2020 ◽  
Vol 12 (3) ◽  
pp. 382 ◽  
Author(s):  
Justin Murfitt ◽  
Claude R. Duguay
Keyword(s):  
Time Series ◽  
Difference Method ◽  
Time Of Day ◽  
High Density ◽  
Average Error ◽  
Visual Interpretation ◽  
Lake Ice ◽  
Sar Images ◽  
Otsu Method ◽  
Ice Phenology

Lake ice is a dominant component of Canada’s landscape and can act as an indicator for how freshwater aquatic ecosystems are changing with warming climates. While lake ice monitoring through government networks has decreased in the last three decades, the increased availability of remote sensing images can help to provide consistent spatial and temporal coverage for areas with annual ice cover. Synthetic aperture radar (SAR) data are commonly used for lake ice monitoring, due to the acquisition of images in any condition (time of day or weather). Using Sentinel-1 A/B images, a high-density time series of SAR images was developed for Lake Hazen in Nunavut, Canada, from 2015–2018. These images were used to test two different methods of monitoring lake ice phenology: one method using the first difference between SAR images and another that applies the Otsu segmentation method. Ice phenology dates determined from the two methods were compared with visual interpretation of the Sentinel-1 images. Mean errors for the pixel comparison of the first difference method ranged 3–10 days for ice-on and ice-off, while average error values for the Otsu method ranged 2–10 days. Mean errors for comparisons of different sections of the lake ranged 0–15 days for the first difference method and 2–17 days for the Otsu method. This research demonstrates the value of temporally consistent image acquisition for improving the accuracy of lake ice monitoring.

Utilization of Warning Lights and Siren Based on Hospital Time-Critical Interventions

2010 ◽  
Vol 25 (4) ◽  
pp. 335-339 ◽  
Author(s):  
Andreia Marques-Baptista ◽  
Pamela Ohman-Strickland ◽  
Kimberly T. Baldino ◽  
Michael Prasto ◽  
Mark A. Merlin
Keyword(s):  
Life Support ◽  
Advanced Life Support ◽  
Time Of Day ◽  
Average Difference ◽  
Transport Time ◽  
Day Of The Week ◽  
Medical Transport ◽  
Critical Patients ◽  
Time Critical ◽  
Warning Lights

AbstractObjective:The objective of this study was to evaluate the time saved by usage of lights and siren (L&S) during emergency medical transport and measure the total number of time-critical hospital interventions gained by this time difference.Methods:A retrospective study was performed of all advanced life support (ALS) transports using lights and siren to this university emergency department during a three-week period. Consecutive times were measured for 112 transports and compared with measured transport times for a personal vehicle traveling the same day of the week and time of day without lights and siren. The time-critical hospital interventions are defined as procedures or treatments that could not be performed in the prehospital setting requiring a physician. The project assessed whether the patients received the hospital interventions within the average time saved using lights and siren transport.Results:The average difference in time with versus without L&S was -2.62 minutes (95% CI: -2.60− -2.63, paired t-test p <0.0001). The average transport time with L&S was 14.5 ±7.9 minutes (min) (1 standard deviation/minute (min), range = 1–36 min.). The average transport time without L&S was 17.1 ±8.3 min (range = 1−40 min). Of the 112 charts evaluated, five patients (4.5%) received time-critical hospital interventions. No patients received time-critical interventions within the time saved by utilizing lights and siren. Longer distances did not result in time saved with lights and siren.Conclusions:Limiting lights and siren use to the patients requiring hospital interventions will decrease the risks of injury and death, while adding the benefit of time saved in these critical patients.

Insitu needle and fine root respiration in mature slash pine (Pinuselliottii) trees

1991 ◽  
Vol 21 (11) ◽  
pp. 1589-1595 ◽  
Author(s):  
Wendell P. Cropper Jr. ◽  
Henry L. Gholz
Keyword(s):  
Time Series ◽  
Fine Roots ◽  
Root Respiration ◽  
Fine Root ◽  
Time Of Day ◽  
Slash Pine ◽  
Chamber System ◽  
North Central ◽  
Central Florida ◽  
Respiration Rates

Respiration of needles and surface fine roots was measured in a north central Florida slash pine (Pinuselliottii Engelm. var. elliottii) plantation. A controlled temperature chamber system was used to estimate respiration rates and Q10 values of insitu tissues over a range of 10 to 35 °C. Respiration rates did not differ significantly among seasons, fertilized versus unfertilized plots, or time of day in a diurnal time series (needles). Needle respiration from the lower canopy was less than that from the upper canopy. Fine root respiration measurements were consistent with previously made estimates based on soil CO2 partitioning and trenched plots.

Interrupted Time Series Analysis in Clinical Research

2003 ◽  
Vol 37 (7-8) ◽  
pp. 1110-1116 ◽  
Author(s):  
Lloyd K Matowe ◽  
Cathie A Leister ◽  
Concetta Crivera ◽  
Joan M Korth-Bradley
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Interrupted Time Series ◽  
Time Of Day ◽  
Series Data ◽  
Simulated Patients ◽  
Interrupted Time Series Analysis ◽  
Data Set ◽  
Additional Tool ◽  
Series Analysis

OBJECTIVE: To demonstrate the usefulness of interrupted time series analysis in clinical trial design. METHODS: A safety data set of electrocardiographic (ECG) information was simulated from actual data that had been collected in a Phase I study. Simulated data on 18 healthy volunteers based on a study performed in a contract research facility were collected based on single doses of an experimental medication that may affect ECG parameters. Serial ECGs were collected before and during treatment with the experimental medication. Data from 7 real subjects receiving placebo were used to simulate the pretreatment phase of time series; data from 18 real subjects receiving active treatment were used to simulate the treatment phase of the time series. Visual inspection of data was performed, followed by tests for trend, seasonality, and autocorrelation by use of SAS. RESULTS: There was no evidence of trend, seasonality, or autocorrelation. In 11 of 18 simulated individuals, statistically significant changes in QTc intervals were observed following treatment with the experimental medication. A significant time of day and treatment interaction was observed in 4 simulated patients. CONCLUSIONS: Interrupted time series analysis techniques offer an additional tool for the study of clinical situations in which patients must act as their own controls and where serial data can be collected at evenly distributed intervals.

Effects of Running on Moods: A Time Series Study

1987 ◽  
Vol 64 (3) ◽  
pp. 783-789 ◽  
Author(s):  
John B. Dyer ◽  
Joyce G. Crouch
Keyword(s):  
Time Series ◽  
Mood State ◽  
Positive Mood ◽  
Time Of Day ◽  
State University ◽  
Time Series Study ◽  
Mood Changes ◽  
Series Design ◽  
Changes Over Time ◽  
Series Study

The purpose of this study was to compare the mood variation in runners of differing ability and commitment to running and the time at which they ran. The subjects, 32 male and 27 female undergraduates of a state university, were in one of three groups based on ability and commitment to running. A time-series design was utilized whereby each group completed four Profile of Mood State questionnaires over a 6-hr. period that centered on the time of day at which subjects ran. All subjects completed a 12-item Commitment to Running scale. Both groups of runners had significantly more positive POMS mood profiles than nonrunners. Mood changes over time suggest that the activity of running may improve one's mood and that moderate levels of running result in positive mood profiles comparable to those of advanced runners.

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