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1.
IEEE Trans Neural Netw Learn Syst ; 34(2): 586-600, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-33690126

RESUMEN

Multi-view classification with limited sample size and data augmentation is a very common machine learning (ML) problem in medicine. With limited data, a triplet network approach for two-stage representation learning has been proposed. However, effective training and verifying the features from the representation network for their suitability in subsequent classifiers are still unsolved problems. Although typical distance-based metrics for the training capture the overall class separability of the features, the performance according to these metrics does not always lead to an optimal classification. Consequently, an exhaustive tuning with all feature-classifier combinations is required to search for the best end result. To overcome this challenge, we developed a novel nearest-neighbor (NN) validation strategy based on the triplet metric. This strategy is supported by a theoretical foundation to provide the best selection of the features with a lower bound of the highest end performance. The proposed strategy is a transparent approach to identify whether to improve the features or the classifier. This avoids the need for repeated tuning. Our evaluations on real-world medical imaging tasks (i.e., radiation therapy delivery error prediction and sarcoma survival prediction) show that our strategy is superior to other common deep representation learning baselines [i.e., autoencoder (AE) and softmax]. The strategy addresses the issue of feature's interpretability which enables more holistic feature creation such that the medical experts can focus on specifying relevant data as opposed to tedious feature engineering.


Asunto(s)
Diagnóstico por Imagen , Redes Neurales de la Computación , Aprendizaje Automático
2.
Phys Med Biol ; 66(24)2021 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-34757951

RESUMEN

We have designed and modeled a novel optical system composed of a Laue lens coupled to an x-ray tube that produces a focused beam in an energy range near 100 keV (λ= 12.4 picometer). One application of this system is radiation therapy where it could enable treatment units that are considerably simpler and lower in cost than present technologies relying on linear accelerators. The Laue lens is made of Silicon Laue components which exploit the silicon pore optics technology. The lens concentrates photons to a small region thus allowing high dose rates at the focal area with very much lower dose rates at the skin and superficial regions. Monte Carlo simulations with Geant4 indicate a dose deposition rate of 0.2 Gy min-1in a cylindrical volume of 0.7 mm diameter and 10 mm length, and a dose ratio of 72 at the surface (skin) compared to the focus placed 10 cm within a water phantom. Work is ongoing to newer generation crystal technologies to increase dose rate.


Asunto(s)
Fotones , Silicio , Método de Montecarlo , Fantasmas de Imagen , Fotones/uso terapéutico , Radiometría , Rayos X
3.
J Med Internet Res ; 20(8): e10458, 2018 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-30087090

RESUMEN

BACKGROUND: The Meaningful Use (MU) program has promoted electronic health record adoption among US hospitals. Studies have shown that electronic health record adoption has been slower than desired in certain types of hospitals; but generally, the overall adoption rate has increased among hospitals. However, these studies have neither evaluated the adoption of advanced functionalities of electronic health records (beyond MU) nor forecasted electronic health record maturation over an extended period in a holistic fashion. Additional research is needed to prospectively assess US hospitals' electronic health record technology adoption and advancement patterns. OBJECTIVE: This study forecasts the maturation of electronic health record functionality adoption among US hospitals through 2035. METHODS: The Healthcare Information and Management Systems Society (HIMSS) Analytics' Electronic Medical Record Adoption Model (EMRAM) dataset was used to track historic uptakes of various electronic health record functionalities considered critical to improving health care quality and efficiency in hospitals. The Bass model was used to predict the technological diffusion rates for repeated electronic health record adoptions where upgrades undergo rapid technological improvements. The forecast used EMRAM data from 2006 to 2014 to estimate adoption levels to the year 2035. RESULTS: In 2014, over 5400 hospitals completed HIMSS' annual EMRAM survey (86%+ of total US hospitals). In 2006, the majority of the US hospitals were in EMRAM Stages 0, 1, and 2. By 2014, most hospitals had achieved Stages 3, 4, and 5. The overall technology diffusion model (ie, the Bass model) reached an adjusted R-squared of .91. The final forecast depicted differing trends for each of the EMRAM stages. In 2006, the first year of observation, peaks of Stages 0 and 1 were shown as electronic health record adoption predates HIMSS' EMRAM. By 2007, Stage 2 reached its peak. Stage 3 reached its full height by 2011, while Stage 4 peaked by 2014. The first three stages created a graph that exhibits the expected "S-curve" for technology diffusion, with inflection point being the peak diffusion rate. This forecast indicates that Stage 5 should peak by 2019 and Stage 6 by 2026. Although this forecast extends to the year 2035, no peak was readily observed for Stage 7. Overall, most hospitals will achieve Stages 5, 6, or 7 of EMRAM by 2020; however, a considerable number of hospitals will not achieve Stage 7 by 2035. CONCLUSIONS: We forecasted the adoption of electronic health record capabilities from a paper-based environment (Stage 0) to an environment where only electronic information is used to document and direct care delivery (Stage 7). According to our forecasts, the majority of hospitals will not reach Stage 7 until 2035, absent major policy changes or leaps in technological capabilities. These results indicate that US hospitals are decades away from fully implementing sophisticated decision support applications and interoperability functionalities in electronic health records as defined by EMRAM's Stage 7.


Asunto(s)
Registros Electrónicos de Salud/tendencias , Hospitales/tendencias , Calidad de la Atención de Salud/normas , Humanos , Estudios Retrospectivos , Estados Unidos
4.
J Cancer Educ ; 32(2): 364-373, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26472325

RESUMEN

The 68 National Cancer Institute (NCI)-designated comprehensive and cancer centers have been tasked with leading the campaign in the fight against cancer, as well as providing education and outreach to the public. Therefore, it is important for these organizations to have an effective online presence to disseminate information and engage patients. The purpose of this study was to assess both the functionality and usability of cancer centers' websites. The 68 center web domains were evaluated using two separate but complementary approaches. First, a webcrawler was used to score each website on five dimensions: accessibility, content, marketing, technology, and usability. Rankings on each dimension and an average ranking were calculated for all 68 centers. Second, a three-reader system was used to determine a list of all functionalities present on the websites. Both webcrawler scores and functionality prevalence were compared across center type. No differences were observed in webcrawler scores between comprehensive and cancer centers. Mean scores on all dimensions ranged between 5.47 and 7.09. For the functionality assessment, 64 unique functions were determined and categorized into 12 domains, with the average center possessing less than 50 % of the functions. This census assessment of NCI centers' websites suggests the need for improvement to capitalize on new dissemination platforms available online. Progress in development of this technology can help achieve the goals of public education and outreach to a broad audience. This paper presents performance guidelines evaluated against best-demonstrated practice to facilitate social media use improvement.


Asunto(s)
Benchmarking , Información de Salud al Consumidor/normas , Internet , National Cancer Institute (U.S.)/normas , Medios de Comunicación Sociales/normas , Relaciones Comunidad-Institución , Humanos , Educación del Paciente como Asunto , Estados Unidos
5.
J Vis Exp ; (81): e50716, 2013 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-24300415

RESUMEN

The functional characterization of adult-born neurons remains a significant challenge. Approaches to inhibit adult neurogenesis via invasive viral delivery or transgenic animals have potential confounds that make interpretation of results from these studies difficult. New radiological tools are emerging, however, that allow one to noninvasively investigate the function of select groups of adult-born neurons through accurate and precise anatomical targeting in small animals. Focal ionizing radiation inhibits the birth and differentiation of new neurons, and allows targeting of specific neural progenitor regions. In order to illuminate the potential functional role that adult hypothalamic neurogenesis plays in the regulation of physiological processes, we developed a noninvasive focal irradiation technique to selectively inhibit the birth of adult-born neurons in the hypothalamic median eminence. We describe a method for Computer tomography-guided focal irradiation (CFIR) delivery to enable precise and accurate anatomical targeting in small animals. CFIR uses three-dimensional volumetric image guidance for localization and targeting of the radiation dose, minimizes radiation exposure to nontargeted brain regions, and allows for conformal dose distribution with sharp beam boundaries. This protocol allows one to ask questions regarding the function of adult-born neurons, but also opens areas to questions in areas of radiobiology, tumor biology, and immunology. These radiological tools will facilitate the translation of discoveries at the bench to the bedside.


Asunto(s)
Hipotálamo/citología , Hipotálamo/efectos de la radiación , Neurogénesis/efectos de la radiación , Neuronas/citología , Neuronas/efectos de la radiación , Tomografía Computarizada por Rayos X/métodos , Animales , Femenino , Histonas/metabolismo , Inmunohistoquímica , Ratones , Ratones Endogámicos C57BL , Células-Madre Neurales/citología , Células-Madre Neurales/efectos de la radiación , Tomografía Computarizada por Rayos X/instrumentación
6.
Health Care Manage Rev ; 33(1): 60-8, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18091445

RESUMEN

BACKGROUND: The return on investment for information technology (IT) has been the subject of much debate throughout the history of management information systems research. Often referred to as the productivity paradox, increased IT investments have not been consistently associated with increased productivity. Understanding individual IT factors that directly contribute to business value should provide insight into the productivity paradox. PURPOSE: The effects of 3 different firm-level IT characteristics on financial performance in the health care industry are studied. Specifically, the effects of IT budget, IT outsourcing, and the relative number of IT personnel on firm-level financial performance are analyzed. METHODS: Regression analysis of archival survey data for 914 Integrated Healthcare Delivery Systems is performed. RESULTS: IT budgetary expenditures and the number of IT services outsourced are associated with increases in the profitability of Integrated Healthcare Delivery Systems, whereas increases in IT personnel are not significantly associated with increased profitability. Each one tenth of a percentage increase in IT expenditures is associated with approximately $100,000 in increased profit, and each additional IT service outsourced is associated with approximately $950,000 in increased profit for an average-sized Integrated Healthcare Delivery System. IMPLICATIONS: To increase profitability, IT administrators should increase IT budgetary expenditures along with IT outsourcing levels. IT administrators in the health care industry can use such findings during budgeting cycles to justify increased investments in IT personnel as being budget neutral while increasing organizational capacity.


Asunto(s)
Gastos de Capital , Prestación Integrada de Atención de Salud/organización & administración , Eficiencia Organizacional , Sistemas de Información/economía , Inversiones en Salud , Presupuestos , Análisis Costo-Beneficio , Prestación Integrada de Atención de Salud/economía , Encuestas de Atención de la Salud , Humanos , Sistemas de Información/estadística & datos numéricos , Análisis de Regresión , Estados Unidos
7.
Int J Radiat Oncol Biol Phys ; 63(1): 301-7, 2005 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-16111600

RESUMEN

PURPOSE: To evaluate a fluoroscopy-based intraoperative dosimetry system to guide placement of additional sources to underdosed areas, and perform computed tomography (CT) verification. METHODS AND MATERIALS: Twenty-six patients with prostate carcinoma treated with either I-125 or Pd-103 brachytherapy at the Puget Sound VA using intraoperative postimplant dosimetry were analyzed. Implants were performed by standard techniques. After completion of the initial planned brachytherapy procedure, the initial fluoroscopic intraoperative dose reconstruction analysis (I-FL) was performed with three fluoroscopic images acquired at 0 (AP), +15, and -15 degrees. Automatic seed identification was performed and the three-dimensional (3D) seed coordinates were computed and imported into VariSeed for dose visualization. Based on a 3D assessment of the isodose patterns additional seeds were implanted, and the final fluoroscopic intraoperative dose reconstruction was performed (FL). A postimplant computed tomography (CT) scan was obtained after the procedure and dosimetric parameters and isodose patterns were analyzed and compared. RESULTS: An average of 4.7 additional seeds were implanted after intraoperative analysis of the dose coverage (I-FL), and a median of 5 seeds. After implantation of additional seeds the mean V100 increased from 89% (I-FL) to 92% (FL) (p < 0.001). In I-125 patients an improvement from 91% to 94% (p = 0.01), and 87% to 93% (p = 0.001) was seen for Pd-103. The D90 increased from 105% (I-FL) to 122% (FL) (p < 0.001) for I-125, and 92% (I-FL) to 102% (FL) (p = 0.008) for Pd-103. A minimal change occurred in the R100 from a mean of 0.32 mL (I-FL) to 0.6 mL (FL) (p = 0.19). No statistical difference was noted in the R100 (rectal volume receiving 100% of the prescribed dose) between the two techniques. The rate of adverse isodose patterns decreased between I-FL and FL from 42% to 8%, respectively. The I-125 patients demonstrated a complete resolution of adverse isodose patterns after the initial isodose reconstruction (I-FL). The Pd-103 patients demonstrated a final rate of 8% gaps, 0% islands, and 0% holes on corrected isodose reconstruction. CONCLUSION: The use of intraoperative fluoroscopy-based dose assessment can accurately guide in the implantation of additional sources to supplement inadequately dosed areas within the prostate gland. Additionally, guided implantation of additional source, can significantly improve V100s and D90s, without significantly increasing rectal doses.


Asunto(s)
Braquiterapia/métodos , Neoplasias de la Próstata/radioterapia , Radiometría/métodos , Braquiterapia/instrumentación , Fluoroscopía/métodos , Humanos , Periodo Intraoperatorio , Radioisótopos de Yodo/uso terapéutico , Masculino , Paladio/uso terapéutico , Neoplasias de la Próstata/diagnóstico por imagen , Radioisótopos/uso terapéutico , Dosificación Radioterapéutica , Tomografía Computarizada por Rayos X
8.
Health Care Manage Rev ; 29(2): 159-69, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15192988

RESUMEN

Health care organizations often enter into a cooperative arrangement to create safety-net programs and coordinate care. Maintaining effective cooperation in such alliances poses special problems that can be examined using network analysis and explained in game theory terms. A mental health coalition case study is presented using network analysis and game theory interpretations. Had a positive-sum game approach been applied to the coalition's initial design, its subsequent suboptimal performance might have been averted. The application of network analysis plus a game theoretic paradigm has significant implications for improving both the design and the coordination of such coalitions.


Asunto(s)
Planificación en Salud Comunitaria/métodos , Servicios Comunitarios de Salud Mental/organización & administración , Prestación Integrada de Atención de Salud/organización & administración , Teoría del Juego , Federación para Atención de Salud , Conducta Cooperativa , Investigación sobre Servicios de Salud , Humanos , Relaciones Interinstitucionales , Liderazgo , Estudios de Casos Organizacionales , Innovación Organizacional , Técnicas de Planificación , Desarrollo de Programa , Estados Unidos
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