187 research outputs found
The invention of fiberoptic videoguide intubation
Introduction: Airway management is one of the most important medical priorities. Despite its benefits, intubation can be sometimes associated with many complications and hardships. Hard intubation can have dangerous consequences, including hypoxia, increased intracranial pressure, cardiac collapse-vascular, traumatic anatomical areas and inflammation. The purpose of this device building is to reduce such complications.Material and Method: This tool can be used to examine film and photographs of pharyngeal organs, epiglottis, vocal cords and proximal esophagus episodes and the upper esophagus, trachea and bronchi.Discussion: Conventional laryngoscopes and video laryngoscopes are the instruments used in intubation, each of which has its own functional limitations. Of these limitations, it is difficult to intubate that due to the lack of proper view of the anatomical routes, the processor may fail. Fiberopathic videography is a tool that can be used in the chest tube intubation, especially in difficult conditions, operating rooms, and other pre-hospital settings.Results: Fiberopathic videography, a simple and very inexpensive tool that can visualize anatomical paths, shape simplicity directly facilitates the process of commuting and reduces potential complications.Keywords: Fiberoptic, Videoguide, Intubation, Thrace
Discrete breathers assist energy transfer to ac driven nonlinear chains
One-dimensional chain of pointwise particles harmonically coupled with
nearest neighbors and placed in six-order polynomial on-site potentials is
considered. Power of the energy source in the form of single ac driven
particles is calculated numerically for different amplitudes and
frequencies within the linear phonon band. The results for the on-site
potentials with hard and soft nonlinearity types are compared. For the
hard-type nonlinearity, it is shown that when the driving frequency is close to
(far from) the {\em upper} edge of the phonon band, the power of the energy
source normalized to increases (decreases) with increasing . In
contrast, for the soft-type nonlinearity, the normalized power of the energy
source increases (decreases) with increasing when the driving frequency is
close to (far from) the {\em lower} edge of the phonon band. Our further
demonstrations indicate that, in the case of hard (soft) anharmonicity, the
chain can support movable discrete breathers (DBs) with frequencies above
(below) the phonon band. It is the energy source quasi-periodically emitting
moving DBs in the regime with driving frequency close to the DBs frequency,
that induces the increase of the power. Therefore, our results here support the
mechanism that the moving DBs can assist energy transfer from the ac driven
particle to the chain.Comment: 11 pages, 13 figure
Soliton-potential interaction in the nonlinear Klein-Gordon model
The interaction of solitons with external potentials in nonlinear
Klein-Gordon field theory is investigated using an improved model. The
presented model has been constructed with a better approximation for adding the
potential to the Lagrangian through the metric of background space-time. The
results of the model are compared with another model and the differences are
discussed.Comment: 14 pages,8 figure
No Tradeoff between Coherence and Sub-Poissonianity for Heisenberg-Limited Lasers
The Heisenberg limit to laser coherence -- the number of
photons in the maximally populated mode of the laser beam -- is the fourth
power of the number of excitations inside the laser. We generalize the previous
proof of this upper bound scaling by dropping the requirement that the beam
photon statistics be Poissonian (i.e., Mandel's ). We then show that the
relation between and sub-Poissonianity () is win-win, not a
tradeoff. For both regular (non-Markovian) pumping with semi-unitary gain
(which allows ), and random (Markovian) pumping with
optimized gain, is maximized when is minimized.Comment: This is a companion letter to the manuscript entitled "Optimized
Laser Models with Heisenberg-Limited Coherence and Sub-Poissonian Beam Photon
Statistics", arxiv:2208.14082. 6 pages, 2 figure
The Heisenberg limit for laser coherence
To quantify quantum optical coherence requires both the particle- and
wave-natures of light. For an ideal laser beam [1,2,3], it can be thought of
roughly as the number of photons emitted consecutively into the beam with the
same phase. This number, , can be much larger than , the
number of photons in the laser itself. The limit on for an ideal
laser was thought to be of order [4,5]. Here, assuming nothing about
the laser operation, only that it produces a beam with certain properties close
to those of an ideal laser beam, and that it does not have external sources of
coherence, we derive an upper bound: . Moreover, using
the matrix product states (MPSs) method [6,7,8,9], we find a model that
achieves this scaling, and show that it could in principle be realised using
circuit quantum electrodynamics (QED) [10]. Thus is
only a standard quantum limit (SQL); the ultimate quantum limit, or Heisenberg
limit, is quadratically better.Comment: 6 pages, 4 figures, and 31 pages of supplemental information. v2:
This paper is now published [Nature Physics DOI:10.1038/s41567-020-01049-3
(26 October 2020)]. For copyright reasons, this arxiv paper is based on a
version of the paper prior to the accepted (21 August 2020) versio
Applications of different machine learning approaches in prediction of breast cancer diagnosis delay
Background: The increasing rate of breast cancer (BC) incidence and mortality in Iran has turned this disease into a challenge. A delay in diagnosis leads to more advanced stages of BC and a lower chance of survival, which makes this cancer even more fatal. Objectives: The present study was aimed at identifying the predicting factors for delayed BC diagnosis in women in Iran.Methods: In this study, four machine learning methods, including extreme gradient boosting (XGBoost), random forest (RF), neural networks (NNs), and logistic regression (LR), were applied to analyze the data of 630 women with confirmed BC. Also, different statistical methods, including chi-square, p-value, sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC), were utilized in different steps of the survey.Results: Thirty percent of patients had a delayed BC diagnosis. Of all the patients with delayed diagnoses, 88.5% were married, 72.1% had an urban residency, and 84.8% had health insurance. The top three important factors in the RF model were urban residency (12.04), breast disease history (11.58), and other comorbidities (10.72). In the XGBoost, urban residency (17.54), having other comorbidities (17.14), and age at first childbirth (>30) (13.13) were the top factors; in the LR model, having other comorbidities (49.41), older age at first childbirth (82.57), and being nulliparous (44.19) were the top factors. Finally, in the NN, it was found that being married (50.05), having a marriage age above 30 (18.03), and having other breast disease history (15.83) were the main predicting factors for a delayed BC diagnosis.Conclusion: Machine learning techniques suggest that women with an urban residency who got married or had their first child at an age older than 30 and those without children are at a higher risk of diagnosis delay. It is necessary to educate them about BC risk factors, symptoms, and self-breast examination to shorten the delay in diagnosis
Using machine learning in prediction of ICU admission, mortality, and length of stay in the early stage of admission of COVID-19 patients
The recent COVID-19 pandemic has affected health systems across the world. Especially, Intensive Care Units (ICUs) have played a pivotal role in the treatment of critically-ill patients. At the same time however, the increasing number of admissions due to the vast prevalence of the virus have caused several problems for ICU wards such as overburdening of staff and shortages of medical resources. These issues might have affected the quality of healthcare services provided directly impacting a patient’s survival. The objective of this research is to leverage Machine Learning (ML) on hospital data in order to support hospital managers and practitioners with the treatment of COVID-19 patients. This is accomplished by providing more detailed inference about a patient’s likelihood of ICU admission, mortality and in case of hospitalization the length of stay (LOS). In this pursuit, the outcome variables are in three separate models predicted by five different ML algorithms: eXtreme Gradient Boosting (XGB), K-Nearest Neighbor (KNN), Random Forest (RF), bagged-CART (b-CART), and LogitBoost (LB). With the exception of KNN, the studied models show good predictive capabilities when evaluating relevant accuracy scores, such as area under the curve. By implementing an ensemble stacking approach (either a Neural Net or a General Linear Model) on top of the aforementioned ML algorithms the performance is further boosted. Ultimately, for the prediction of admission to the ICU, the ensemble stacking via a Neural Net achieved the best result with an accuracy of over 95%. For mortality at the ICU, the vanilla XGB performed slightly better (1% difference with the meta-model). To predict large length of stays both ensemble stacking approaches yield comparable results. Besides it direct implications for managing COVID-19 patients, the approach presented serves as an example how data can be employed in future pandemics or crises
Optimized Laser Models with Heisenberg-Limited Coherence and Sub-Poissonian Beam Photon Statistics
Recently it has been shown that it is possible for a laser to produce a
stationary beam with a coherence (quantified as the mean photon number at
spectral peak) which scales as the fourth power of the mean number of
excitations stored within the laser, this being quadratically larger than the
standard or Schawlow-Townes limit [1]. Moreover, this was analytically proven
to be the ultimate quantum limit (Heisenberg limit) scaling under defining
conditions for CW lasers, plus a strong assumption about the properties of the
output beam. In Ref. [2], we show that the latter can be replaced by a weaker
assumption, which allows for highly sub-Poissonian output beams, without
changing the upper bound scaling or its achievability. In this Paper, we
provide details of the calculations in Ref. [2], and introduce three new
families of laser models which may be considered as generalizations of those
presented in that work. Each of these families of laser models is parameterized
by a real number, , with corresponding to the original models. The
parameter space of these laser families is numerically investigated in detail,
where we explore the influence of these parameters on both the coherence and
photon statistics of the laser beams. Two distinct regimes for the coherence
may be identified based on the choice of , where for , each family of
models exhibits Heisenberg-limited beam coherence, while for , the
Heisenberg limit is no longer attained. Moreover, in the former regime, we
derive formulae for the beam coherence of each of these three laser families
which agree with the numerics. We find that the optimal parameter is in fact
, not .Comment: This is a companion manuscript to the letter entitled "No Tradeoff
between Coherence and Sub-Poissonianity for Heisenberg-Limited Lasers",
arxiv:2208.14081. 22 pages, 11 figure
Design Space Exploration for Distributed Cyber-Physical Systems: State-of-the-art, Challenges, and Directions
Computer Systems, Imagery and Medi
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