Design and Experimental Validation of Deep Reinforcement Learning-Based Fast Trajectory Planning and Control for Mobile Robot in Unknown Environment.

This article is concerned with the problem of planning optimal maneuver trajectories and guiding the mobile robot toward target positions in uncertain environments for exploration purposes. A hierarchical deep learning-based control framework is proposed which consists of an upper level motion planning layer and a lower level waypoint tracking layer. In the motion planning phase, a recurrent deep neural network (RDNN)-based algorithm is adopted to predict the optimal maneuver profiles for the mobile robot. This approach is built upon a recently proposed idea of using deep neural networks (DNNs) to approximate the optimal motion trajectories, which has been validated that a fast approximation performance can be achieved. To further enhance the network prediction performance, a recurrent network model capable of fully exploiting the inherent relationship between preoptimized system state and control pairs is advocated. In the lower level, a deep reinforcement learning (DRL)-based collision-free control algorithm is established to achieve the waypoint tracking task in an uncertain environment (e.g., the existence of unexpected obstacles). Since this approach allows the control policy to directly learn from human demonstration data, the time required by the training process can be significantly reduced. Moreover, a noisy prioritized experience replay (PER) algorithm is proposed to improve the exploring rate of control policy. The effectiveness of applying the proposed deep learning-based control is validated by executing a number of simulation and experimental case studies. The simulation result shows that the proposed DRL method outperforms the vanilla PER algorithm in terms of training speed. Experimental videos are also uploaded, and the corresponding results confirm that the proposed strategy is able to fulfill the autonomous exploration mission with improved motion planning performance, enhanced collision avoidance ability, and less training time.

Distributed Neural Networks Training for Robotic Manipulation With Consensus Algorithm.

In this article, we propose an algorithm that combines actor-critic-based off-policy method with consensus-based distributed training to deal with multiagent deep reinforcement learning problems. Specifically, convergence analysis of a consensus algorithm for a type of nonlinear system with a Lyapunov method is developed, and we use this result to analyze the convergence properties of the actor training parameters and the critic training parameters in our algorithm. Through the convergence analysis, it can be verified that all agents will converge to the same optimal model as the training time goes to infinity. To validate the implementation of our algorithm, a multiagent training framework is proposed to train each Universal Robot 5 (UR5) robot arm to reach the random target position. Finally, experiments are provided to demonstrate the effectiveness and feasibility of the proposed algorithm.

GECOP-MMC: phase IV randomized clinical trial to evaluate the efficacy of hyperthermic intraperitoneal chemotherapy (HIPEC) with mytomicin-C after complete surgical cytoreduction in patients with colon cancer peritoneal metastases.

BACKGROUND: The French PRODIGE 7 trial, published on January 2021, has raised doubts about the specific survival benefit provided by HIPEC with oxaliplatin 460 mg/m2 (30 minutes) for the treatment of peritoneal metastases from colorectal cancer. However, several methodological flaws have been identified in PRODIGE 7, specially the HIPEC protocol or the choice of overall survival as the main endpoint, so its results have not been assumed as definitive, emphasizing the need for further research on HIPEC. It seems that the HIPEC protocol with high-dose mytomicin-C (35 mg/m2) is the preferred regime to evaluate in future clinical studies. METHODS: GECOP-MMC is a prospective, open-label, randomized, multicenter phase IV clinical trial that aims to evaluate the effectiveness of HIPEC with high-dose mytomicin-C in preventing the development of peritoneal recurrence in patients with limited peritoneal metastasis from colon cancer (not rectal), after complete surgical cytoreduction. This study will be performed in 31 Spanish HIPEC centres, starting in March 2022. Additional international recruiting centres are under consideration. Two hundred sixteen patients with PCI ≤ 20, in which complete cytoreduction (CCS 0) has been obtained, will be randomized intraoperatively to arm 1 (with HIPEC) or arm 2 (without HIPEC). We will stratified randomization by surgical PCI (1-10; 11-15; 16-20). Patients in both arms will be treated with personalized systemic chemotherapy. Primary endpoint is peritoneal recurrence-free survival at 3 years. An ancillary study will evaluate the correlation between surgical and pathological PCI, comparing their respective prognostic values. DISCUSSION: HIPEC with high-dose mytomicin-C, in patients with limited (PCI ≤ 20) and completely resected (CCS 0) peritoneal metastases, is assumed to reduce the expected risk of peritoneal recurrence from 50 to 30% at 3 years. TRIAL REGISTRATION: EudraCT number: 2019-004679-37; Clinicaltrials.gov: NCT05250648 (registration date 02/22/2022, ).

Negative pressure therapy as palliative treatment for a colonic fistula.

Colonic fistulas in an open wound are always a challenge for colorectal surgeons, and this report provides a technique for the appropriate management of these cases. We communicate the use of a negative pressure dressing therapy as part of the palliative care for a patient following the development of an enterocutaneous fistula. The use of this therapy allowed us to keep the patient clean and comfortable during the last few days of his life.

Teorías subjetivas de profesionales de escuelas de lenguaje en chile sobre el trastorno específico del lenguaje / Subjective theories of professionals of language schools in Chile about Specific Language Impairment

OBJETIVO: comprender y reconstruir las teorías subjetivas de profesionales de escuelas de lenguaje en Chile, sobre las causas y el tratamiento del trastorno específico del lenguaje. MÉTODO: se utilizó métodos cualitativos para recolectar datos en profundidad. Se realizó entrevistas individuales semi-estructuradas con una muestra de cuatro fonoaudiólogas (logopedas) y cuatro educadoras diferenciales de cuatro escuelas de lenguaje. Se grabó y transcribió las entrevistas, las que fueron analizadas con el programa informático Atlas.ti 5.0. Los resultados del análisis relacional se sintetizaron en tres modelos. RESULTADOS: para las fonoaudiólogas y educadoras diferenciales las causas principales del trastorno específico del lenguaje son factores sociales, originados en la familia de los niños afectados. Con respeto a la superación de este trastorno las entrevistadas destacaron con alta importancia el apoyo familiar para un tratamiento eficaz. CONCLUSIONES: entre las explicaciones subjetivas de las profesionales entrevistadas y las explicaciones científicas acerca las causas del trastorno específico del lenguaje, existen diferencias. Mientras las entrevistadas hablan de causas sociales, los enfoques científicos explican este trastorno por causas biológicas. Esta diferencia debería ser investigada en estudios posteriores. Las fonoaudiólogas y educadoras diferenciales ven la familia del niño como una de las causas principales del trastorno específico del lenguaje y al mismo tiempo consideran el apoyo familiar como un requisito crucial en el tratamiento. En la opinión de los profesionales de las escuelas de lenguaje el trastorno específico del lenguaje es un trastorno superable, si escuela y familia trabajan en conjunto.

PURPOSE: understand and reconstruct the Subjective Theories from professionals in language schools in Chile about causes and treatment of Specific Language Impairment. METHOD: qualitative methods were used to recollect data in depth. The sample included four speech therapists and four psychopedagogists from four different language schools. Every participant was interviewed based on an individual, semi-structured interview. The interviews were recorded, transcribed and analyzed with the computer program Atlas.ti 5.0. The results were visualized in three models. RESULTS: according to the speech therapists and the psychopedagogists, social factors within the families of the affected children are the main causes of specific language impairment. With regard to efficient therapy and the overcoming of this impairment, participants emphasized the importance of family support. CONCLUSIONS: the subjective explanations from the interviewed professionals regarding the cause of specific language impairment differ from the scientific explanations: While the participants of this study attribute social causes to specific language impairment, the scientific explanations focus on biological factors. This inconsistency should be investigated in future studies. The speech therapists and psychopedagogists indicate that certain circumstances in families as one of the main causes of the impairment. But at the same time they talk about the family support as a pivotal element in the treatment. As a result, they claim that if school and family work together SLI becomes a superable impairment.

[Solid organ transection. Open and laparoscopic surgery]. / Transección de órganos sólidos. Cirugía abierta y laparoscópica.

Recent advances in liver surgery have reduced post-hepatectomy mortality to less than 5% in most units specialized in hepato-pancreatic-biliary surgery. Possibly, the single most important factor contributing to these improved results has been the reduction in intraoperative bleeding during liver parenchymal transection. Liver transection is the most risky part of the intervention due to the risk of massive hemorrhage. Some technological advances and refinements to the surgical technique have contributed to making this critical phase of liver surgery safer. Among these advances, the most notable are detailed knowledge of the surgical anatomy of the liver, vascular control techniques and methods of liver parenchymal transection. The present review describes current transection techniques, as well as their advantages and disadvantages. Until there is solid evidence on the best method, the choice of technique and instrument for liver transection depends mainly on the surgeon's personal preference. Nevertheless, some factors can influence the choice of method, such as the surgeon's experience, anesthetic management, type of hepatectomy (central, peripheral), type of approach (open, laparoscopic), quality of the liver (normal, cirrhotic, steatotic) and the availability of the instruments in the center.

Transección de órganos sólidos. Cirugía abierta y laparoscópica / Solid organ transection. Open and laparoscopic surgery

Los avances recientes en la cirugía hepática han contribuido a que la mortalidad tras las hepatectomías sea inferior al 5% en la mayoría de las unidades especializadas en cirugía HPB. Posiblemente, el factor aislado más importante que ha contribuido a esta mejoría de resultados ha sido la reducción de la hemorragia intraoperatoria durante la transección del parénquima hepático. La transección hepática es la parte de la operación más comprometida debido al riesgo de que se pueda producir una hemorragia masiva. Algunos avances tecnológicos y refinamientos de la técnica quirúrgica han contribuido a hacer más segura esta fase crítica de la cirugía hepática. De estos avances, los más notables son el conocimiento detallado de la anatomía quirúrgica del hígado, las técnicas de control vascular y los métodos de transección del parénquima hepático. En esta revisión se describen cuáles son las técnicas actuales de transección, así como sus ventajas e inconvenientes. Hasta que no exista una evidencia muy sólida sobre el mejor método, la elección de una técnica y un instrumento para la transección hepática depende fundamentalmente de la preferencia persona ldel cirujano. No obstante, algunos factores pueden influir en la selección de un método u otro, tales como la experiencia del cirujano, el manejo anestésico, el tipo de hepatectomía (central, periférica), el tipo de abordaje (abierto, laparoscópico), la calidad del hígado (normal, cirrótico, esteatósico) y la propia disponibilidad de los instrumentos en el centro (AU)

Recent advances in liver surgery have reduced post-hepatectomy mortality to less than5% in most units specialized in hepato-pancreatic-biliary surgery. Possibly, the single most important factor contributing to these improved results has been the reduction inintraoperative bleeding during liver parenchymal transection. Liver transection is the most risky part of the intervention due to the risk of massive hemorrhage. Some technological advances and refinements to the surgical technique have contributed to making this critical phase of liver surgery safer. Among these advances, the most notable are detailed knowledge of the surgical anatomy of the liver, vascular control techniques and methods of liver parenchymal transection. The present review describes current transection techniques, as well as their advantages and disadvantages. Until there is solid evidence on the best method, the choice of technique and instrument for liver transection depends mainly on the surgeon’s personal preference. Nevertheless, some factors can influence the choice of method, such as the surgeon’s experience, anesthetic management, type of hepatectomy (central, peripheral), type of approach (open, laparoscopic), quality of the liver (normal, cirrhotic, steatotic) and the availability of the instruments in the center (AU)

[Biliary reconstruction in liver transplantation: is a biliary tutor necessary?]. / Reconstrucción biliar en el trasplante hepático: es necesario un tutor biliar.

OBJECTIVES: To assess the incidence and type of biliary complications in liver transplantation after biliary reconstruction with or without a biliary tutor. MATERIAL AND METHOD: A prospective, non-randomized study of 128 consecutive patients undergoing elective liver transplantation was performed. Retransplantations, emergency transplantations, hepaticojejunostomy and patients who died within 3 months of causes other than biliary complications were excluded. Group I (n = 64) underwent termino-terminal choledochocholedochostomy with a Kehr tube and group II (n = 64) underwent choledochocholedochostomy without Kehr tube. Complications, therapeutic procedures, reoperations and survival free of biliary complications were analyzed. RESULTS: The overall rate of biliary complications was 15% (17% in group I and 14% in group II). Types of complication (overall and in groups I and II, respectively) consisted of fistulas 4% (6% vs. 3%), stenosis 8% (4% vs. 12%), and Kehr dysfunction 3%. The mean number of therapeutic procedures, including endoscopic retrograde cholangiopancreatography, percutaneous transhepatic cholangiography, trans-Kehr cholangiography and drainage of collections, was 2.1 vs. 2 per complicated patient. The overall reoperation rate was 5% (2% vs. 9%) (p < 0.05). One-year survival free of biliary complications was 85% vs. 82% (Log Rank = 0.5). CONCLUSIONS: No statistically significant differences were found in complications after choledocho-choledocho anastomosis with or without a biliary tutor. However, the patient group that did not receive a biliary tutor required more complex procedures for treatment of complications, as well as a greater number of reoperations.

Reconstrucción biliar en el trasplante hepático: es necesario un tutor biliar / Biliary reconstruction in liver transplantation: is a biliary tutor necessary

Objetivos. Evaluar la incidencia y el tipo de complicaciones biliares en el trasplante hepático tras la reconstrucción biliar con y sin tutor biliar. Material y método. Estudio prospectivo no aleatorizado en el que se incluyó a 128 pacientes consecutivos sometidos a trasplante hepático electivo, excluyendo del estudio los retrasplantes, trasplantes urgentes, hepaticoyeyunostomía y pacientes fallecidos durante los primeros 3 meses por causas distintas de las complicaciones biliares. En el grupo I (n = 64) se realizó coledococoledocostomía terminoterminal sobre tubo de Kehr y en el grupo II (n = 64), coledococoledocostomía sin tubo de Kehr. Se analizan las complicaciones, los procedimientos terapéuticos, reintervenciones y supervivencia libre de complicaciones biliares. Resultados. La tasa general de complicaciones biliares es del 15% (el 17% en el grupo I y el 14% en el grupo II). En relación con el tipo de complicaciones (grupo I contra grupo II) se observó: fístulas, 4% (el 6 contra el 3%); estenosis, 8% (el 4 contra el 12%); disfunciones del tubo de Kehr, 3%. La media de procedimientos terapéuticos, incluidos colangiografía endoscópica, colangiografía transhepática, colangiografias trans-Kehr y drenaje de colecciones, es 2,1 frente a 2 por paciente complicado. La tasa general de reintervenciones es del 5% (el 2 contra el 9%) (p < 0,05). La supervivencia libre de complicaciones biliares al año es del 85 contra el 82% (test de rangos logarítmicos, 0,5). Conclusiones. No se ha encontrado diferencias estadísticamente significativas de complicaciones tras la anastomosis coledococolédoco con y sin tutor biliar. Sin embargo, el grupo de pacientes en los que no se utilizó tutor biliar ha precisado para el tratamiento de la complicaciones procedimientos más complejos, así como mayor número de reintervenciones (AU)

Objectives. To assess the incidence and type of biliary complications in liver transplantation after biliary reconstruction with or without a biliary tutor. Material and method. A prospective, non-randomized study of 128 consecutive patients undergoing elective liver transplantation was performed. Retransplantations, emergency transplantations, hepaticojejunostomy and patients who died within 3 months of causes other than biliary complications were excluded. Group I (n = 64) underwent termino-terminal choledochocholedochostomy with a Kehr tube and group II (n = 64) underwent choledochocholedochostomy without Kehr tube. Complications, therapeutic procedures, reoperations and survival free of biliary complications were analyzed. Results. The overall rate of biliary complications was 15% (17% in group I and 14% in group II). Types of complication (overall and in groups I and II, respectively) consisted of fistulas 4% (6% vs. 3%), stenosis 8% (4% vs. 12%), and Kehr dysfunction 3%. The mean number of therapeutic procedures, including endoscopic retrograde cholangiopancreatography, percutaneous transhepatic cholangiography, trans-Kehr cholangiography and drainage of collections, was 2.1 vs. 2 per complicated patient. The overall reoperation rate was 5% (2% vs. 9%) (p < 0.05). One-year survival free of biliary complications was 85% vs. 82% (Log Rank = 0.5). Conclusions. No statistically significant differences were found in complications after choledocho-choledocho anastomosis with or without a biliary tutor. However, the patient group that did not receive a biliary tutor required more complex procedures for treatment of complications, as well as a greater number of reoperations (AU)