256 research outputs found
CACTO: Continuous Actor-Critic with Trajectory Optimization -- Towards global optimality
This paper presents a novel algorithm for the continuous control of dynamical
systems that combines Trajectory Optimization (TO) and Reinforcement Learning
(RL) in a single framework. The motivations behind this algorithm are the two
main limitations of TO and RL when applied to continuous nonlinear systems to
minimize a non-convex cost function. Specifically, TO can get stuck in poor
local minima when the search is not initialized close to a "good" minimum. On
the other hand, when dealing with continuous state and control spaces, the RL
training process may be excessively long and strongly dependent on the
exploration strategy. Thus, our algorithm learns a "good" control policy via
TO-guided RL policy search that, when used as initial guess provider for TO,
makes the trajectory optimization process less prone to converge to poor local
optima. Our method is validated on several reaching problems featuring
non-convex obstacle avoidance with different dynamical systems, including a car
model with 6D state, and a 3-joint planar manipulator. Our results show the
great capabilities of CACTO in escaping local minima, while being more
computationally efficient than the Deep Deterministic Policy Gradient (DDPG)
and Proximal Policy Optimization (PPO) RL algorithms.Comment: 8 pages, 8 figures. Submitted to IEEE RA-
Robotic Surgery and Deep Infiltrating Endometriosis Treatment: The State of Art
Objective: Surgical treatment of endometriosis, when indicated, has demonstrated to be effective in reducing painful symptoms and improve quality of life of patients affected with endometriosis. The minimally invasive approach via laparoscopy is the preferred method when compared with laparotomy but in the last two decades another minimally invasive approach has become available, the robotically assisted laparoscopic surgery. Robotic technology is widely used in different surgical branches, such as general surgery and urology. Moreover, the use of robotic surgery is already accepted for different gynecological procedures either for benign and for oncological diseases. The advantages of robotic surgery such as improve dexterity of movements, avoided tremor, increased magnification of 3-dimensional vision seem strategic in the context of a complex surgery as is deep endometriosis eradication. However, to date there is no unanimous consensus on whether robotically assisted procedures are a valid and safe alternative to laparoscopy in the treatment of endometriosis. Mechanism: In this narrative review we analyze the available literature assessesing the robotic treatment of all types of endometriosis and specifically deep infiltrating endometriosis, compared to the outcomes of conventional laparoscopy. Findings in Brief: Indeed, the evidence of safety and effectiveness of robotically assisted laparoscopy in endometriosis treatment is strong and almost unanimous. There is no clear superiority of one approach to the other but robotic-related advantages and future prospective are promising to be able to improve operative outcomes, reduce surgeon’s fatigue and provide a technology easy to implement with a fast learning curve. Conclusions: Robotic technology applied to laparoscopy in the treatment of endometriosis could be seen as an effective and safe alternative to the conventional laparoscopic treatment
Gli studenti EIDI al tempo del coronavirus. Risultati della rilevazione online del 21 marzo 2020
Questo rapporto di ricerca presenta i risultati della prima rilevazione di monitoraggio online delle condizioni di vita e di studio degli studenti di Economia e Istituzioni dei Distretti industriali (2019-20) di Unimore (rilevazione on line del 21 marzo 2020). Il monitoraggio on line, che si svolgerà periodicamente fino alla fine del corso (lezioni e esami) è un esperimento di collaborazione che mira a superare l’emergenza covid-19 con maggiore consapevolezza e strumenti per praticare una didattica e uno studio che contribuiscano nel dare a ciascuno studente la possibilità di studiare e procedere nel proprio percorso di studi e di vita nel migliore dei modi. Vengono presentati il questionario, gli strumenti di rilevazione e i risultati che emergono da una prima elaborazione dei dati. Il rapporto si conclude con spunti per la prossima rilevazione e proposte per allargare la rilevazione. Le specifiche proposte didattiche e di studio che sono emerse anche grazie al primo monitoraggio non sono presentate in questo rapporto: sono in continua evoluzione e sono condivise con gli studenti nella piattaforma online del corso
RHYTHM-AF: design of an international registry on cardioversion of atrial fibrillation and characteristics of participating centers
BACKGROUND Atrial fibrillation is a serious public health problem posing a considerable burden to not only patients, but the healthcare environment due to high rates of morbidity, mortality, and medical resource utilization. There are limited data on the variation in treatment practice patterns across different countries, healthcare settings and the associated health outcomes. METHODS/DESIGN RHYTHM-AF was a prospective observational multinational study of management of recent onset atrial fibrillation patients considered for cardioversion designed to collect data on international treatment patterns and short term outcomes related to cardioversion. We present data collected in 10 countries between May 2010 and June 2011. Enrollment was ongoing in Italy and Brazil at the time of data analysis. Data were collected at the time of atrial fibrillation episode in all countries (Australia, Brazil, France, Germany, Italy, Netherlands, Poland, Spain, Sweden, United Kingdom), and cumulative follow-up data were collected at day 60 (±10) in all but Spain. Information on center characteristics, enrollment data, patient demographics, detail of atrial fibrillation episode, medical history, diagnostic procedures, acute treatment of atrial fibrillation, discharge information and the follow-up data on major events and rehospitalizations up to day 60 were collected. DISCUSSIN A total of 3940 patients were enrolled from 175 acute care centers. 70.5% of the centers were either academic (44%) or teaching (26%) hospitals with an overall median capacity of 510 beds. The sites were mostly specialized with anticoagulation clinics (65.9%), heart failure (75.1%) and hypertension clinics (60.1%) available. The RHYTHM-AF registry will provide insight into regional variability of antiarrhythmic and antithrombotic treatment of atrial fibrillation, the appropriateness of such treatments with respect to outcomes, and their cost-efficacy. Observations will help inform strategies to improve cardiovascular outcomes in patients with atrial fibrillation. TRIAL REGISTRATION Clinical trials NCT01119716Harry JGM Crijns, Lori D Bash, François Chazelle, Jean-Yves Le Heuzey, Thorsten Lewalter, Gregory YH Lip, Aldo P Maggioni, Alfonso Martín, Piotr Ponikowski, Mårten Rosenqvist, Prashanthan Sanders, Mauricio Scanavacca, Alexandra A Bernhardt, Sreevalsa Unniachan, Hemant M Phatak and Anselm K Git
Can we improve outcomes in AF patients by early therapy?
Atrial fibrillation affects at least 1% of the population and causes marked society-wide morbidity and mortality. Current management of atrial fibrillation including antithrombotic therapy and management of concomitant conditions in all patients, rate control therapy in most patients, and rhythm control therapy in patients with severe atrial fibrillation-related symptoms can alleviate atrial fibrillation-related symptoms but can neither effectively prevent recurrent atrial fibrillation nor suppress atrial fibrillation-related complications. Hence, there is a need for better therapy of atrial fibrillation
Syncope: experience at a tertiary care hospital in Karachi, Pakistan
Introduction:Our aim was to determine the characteristics of Patients presenting with syncope at a tertiary care hospital in Karachi, Pakistan.Methods: A review of medical records was conducted retrospectively at the Department of Medicine, Aga Khan University Hospital, Karachi. Patients aged 16 and above, admitted from January 2000 to December 2005 with the diagnosis of syncope made by the attending physician were included.Results:A total of 269 Patients were included (75% males, mean age: 57.4 years). Neurogenic (vasovagal) syncope was the most common cause (47%), followed by cardiogenic syncope (18%) and orthostatic syncope (9%). A total of 24% were discharged undiagnosed. Twenty Patients (7.4%) did not have any prodrome. Common prodromal symptoms included dizziness (61%), sweating (25%), palpitations (19%), nausea/vomiting (19%) and visual symptoms (17%). The distribution of symptoms according to cause of syncope revealed only breathlessness to be significantly associated with cardiogenic syncope (p = 0.002). Most Patients with cardiogenic syncope were aged above 40 (98%, p \u3c 0.001), had coronary artery disease (72%, p \u3c 0.001) and abnormal electrocardiogram at presentation (92%, p \u3c 0.001).Conclusion:Despite differences in burden of diseases, our findings were similar to those of published syncope literature. Further studies are needed to develop a protocol to expedite the evaluation and limit the work-up and admission in low-risk Patients
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