Low-Consumption Partial Transcoding by HEVC

A transcoding scheme for the High Efficiency Video Coding (HEVC) is proposed that allows any partial frame modification to be followed by a partial re-compression of only the modified areas, while guaranteeing identical reconstruction of non-modified areas. To this end, first, syntax elements of all Coding Units (CU) in the frame are parsed and decoded according to their scan order. Then CUs that are collocated with a replaced area are re-encoded with new content to generate a partial set of new syntax elements. In order to avoid spatial propagation of the decoding mismatch due to the new content, CUs on the border of the replaced area are losslessly coded such that reconstruction of immediately neighboring CUs in the scan order are protected from the modification. The proposed method has been implemented on top of the HEVC test Model (HM) in All-Intra (AI) coding configuration and experiments show that, depending on the test parameters, it can offer both a bitrate saving (up to 4% in terms of BD-BR) and a transcoding acceleration (up to 83%) compared to a full transcoding scheme

COOL-CHIC: Coordinate-based Low Complexity Hierarchical Image Codec

We introduce COOL-CHIC, a Coordinate-based Low Complexity Hierarchical Image Codec. It is a learned alternative to autoencoders with approximately 2000 parameters and 2500 multiplications per decoded pixel. Despite its low complexity, COOL-CHIC offers compression performance close to modern conventional MPEG codecs such as HEVC and VVC. This method is inspired by the Coordinate-based Neural Representation, where an image is represented as a learned function which maps pixel coordinates to RGB values. The parameters of the mapping function are then sent using entropy coding. At the receiver side, the compressed image is obtained by evaluating the mapping function for all pixel coordinates. COOL-CHIC implementation is made available upon request

Low-complexity Overfitted Neural Image Codec

We propose a neural image codec at reduced complexity which overfits the decoder parameters to each input image. While autoencoders perform up to a million multiplications per decoded pixel, the proposed approach only requires 2300 multiplications per pixel. Albeit low-complexity, the method rivals autoencoder performance and surpasses HEVC performance under various coding conditions. Additional lightweight modules and an improved training process provide a 14% rate reduction with respect to previous overfitted codecs, while offering a similar complexity. This work is made open-source at https://orange-opensource.github.io/Cool-Chic/Comment: Accepted at IEEE MMSP 202

Síndrome de Takotsubo: complicación cardiovascular del accidente cerebrovascular

An 82-year-old woman, Katz A, with a history of type 2 diabetes mellitus and high blood pressure, was admitted for ischemic stroke complicated by Takotsubo ́s syndrome with subsequent readmission for atrial fibrillation after discharge. These three clinical events have criteria to be integrated as a Brain Heart Syndrome, which is a high-risk condition for mortality.Mujer adulta mayor, 82 años, Katz A, con antecedente de diabetes mellitus tipo 2 e hipertensión arterial; ingresa por accidente cerebrovascular isquémico que se complica con síndrome de Takotsubo con posterior reingreso por fibrilación auricular tras el alta médica. Estos tres eventos clínicos tienen criterios para integrarse como un síndrome cerebro-corazón, el cual es una condición de alto riesgo para mortalidad

Prototipo control de vehículo robot por señales EMG

The EMG (Electromyography) signals are basically electrical pulses emitted by the nerves and muscles of the extremities of the human body, (for example the biceps of the arm) which are obtained by means of electrodes. These signals can be amplified and used in different activities or jobs. In the present investigation the EMG signals, acquired from the biceps of the arm to be used, are used by means of three surface electrodes specifically placed to be able to acquire the signals transmitted by the biceps muscles, which with the use of a differential amplifier will be measured and amplified the difference in voltage between the three electrodes that is placed in the muscle, taking into account that the signals are between the ranges of µV and less than 10mV. In the following stages the preparation of the signal is done to connect it to a microcontroller. In this case, the Arduino card will be used, where the already amplified signal is processed and transmitted wirelessly with the help of NRF24L01, which has a range of 1000 meters away from the control system in the Robot Vehicle. In this comes the variation of tension depending on the deflection of the arm and therefore the Robot vehicle accelerates or slows down depending on the signal emitted by the arm amplifier system. Finally, the prototype is adjusted and the fundamental mechanical-electronic characterizations for the different control movements are established.Las señales EMG (Electromiografía) son básicamente pulsos eléctricos emitidos por los nervios y músculos de las extremidades del cuerpo humano, (ejemplo el bíceps del brazo) los que se obtienen por medio de electrodos. Estas señales se pueden amplificar y ser utilizadas en diferentes actividades o trabajos. En la presente investigación se utilizan las señales EMG, adquiridas del bíceps del brazo a utilizar, por medio de tres electrodos superficiales colocados específicamente para poder adquirir las señales trasmitidas por los músculos del bíceps, que con la utilización de un amplificador diferencial se medirá y amplificará la diferencia de voltaje entre los tres electrodos que se coloca en el músculo, teniendo en cuenta que las señales se encuentran entre los rangos de µV y menores de 10mV. En las siguientes etapas se realiza la preparación de la señal para conectarla a un microcontrolador. En este caso se utilizará la tarjeta Arduino, en donde se procesa la señal ya amplificada y se trasmite inalámbricamente con la ayuda del NRF24L01, que tiene un alcance de1000 metros de distancia al sistema de control que está en el Vehículo Robot. En este llega la variación de tensión dependiendo de la deflexión del brazo y por lo tanto el vehículo Robot se acelera o desacelera dependiendo de la señal emitida por el sistema amplificador del brazo. Finalmente se ajusta el prototipo y se establecen las caracterizaciones fundamentales mecánicas-electrónicas para los diferentes movimientos de control

Parallel scalability and efficiency of HEVC parallelization approaches

Unlike H.264/advanced video coding, where parallelism was an afterthought, High Efficiency Video Coding currently contains several proposals aimed at making it more parallel-friendly. A performance comparison of the different proposals, however, has not yet been performed. In this paper, we will fill this gap by presenting efficient implementations of the most promising parallelization proposals, namely tiles and wavefront parallel processing (WPP). In addition, we present a novel approach called overlapped wavefront (OWF), which achieves higher performance and efficiency than tiles and WPP. Experiments conducted on a 12-core system running at 3.33 GHz show that our implementations achieve average speedups, for 4k sequences, of 8.7, 9.3, and 10.7 for WPP, tiles, and OWF, respectively

Shocks as predictors of survival in patients with implantable cardioverter-defibrillators

AbstractOBJECTIVESThe objective of the study was to determine whether the occurrence of shocks for ventricular tachyarrhythmias during therapy with implantable cardioverter-defibrillators (ICD) is predictive of shortened survival.BACKGROUNDVentricular tachyarrhythmias eliciting shocks are often associated with depressed ventricular function, making assessment of shocks as an independent risk factor difficult.METHODSConsecutive patients (n = 421) with a mean follow-up of 756 ± 523 days were classified into those who had received no shock (n = 262) or either one of two shock types, defined as single (n = 111) or multiple shocks (n = 48) per arrhythmia episode. Endpoints were all-cause and cardiac deaths. A survival analysis using a stepwise proportional hazards model evaluated the influence of two primary variables, shock type and left ventricular ejection fraction (LVEF <35% or >35%). Covariates analyzed were age, gender, NYHA Class, coronary artery disease, myocardial infarction, coronary revascularization, defibrillation threshold and tachyarrhythmia inducibility.RESULTSThe most complete model retained LVEF (p = 0.005) and age (p = 0.023) for the comparison of any shock versus no shock (p = 0.031). The occurrence of any versus no shock, or of multiple versus single shocks significantly decreased survival at four years, and these differences persisted after adjustment for LVEF. In the LVEF subgroups <35% and <25%, occurrence of multiple versus no shock more than doubled the risk of death. Compared with the most favorable group LVEF ≥35% and no shock, risk in the group multiple shocks and LVEF <35% was increased 16-fold.CONCLUSIONSIn defibrillator recipients, shocks act as potent predictors of survival independent of several other risk factors, particularly ejection fraction

Presentación atípica del patrón electrocardiográfico de Wellens asociado con lesión de bifurcación coronaria

We present a patient who was admitted to the emergency room due to unstable angina, with an initial electrocardiogram without signs of acute ischemia and a favorable clinical evolution. During hospitalization, she developed the Wellens electrocardiographic pattern, noted in the literature as an infrequent, poorly identified finding and with an ominous prognosis. This electrocardiographic pattern is described in precordial derivatives, suggesting a significant lesion of a principal epicardial artery; our patient had similar electrocardiographic alterations in the high lateral leads, in whom the coronary bifurcation lesion not previously described in this scenario was confirmed.Presentamos el caso de una paciente que ingresó a emergencia por angina inestable, con electrocardiograma inicial sin signos de isquemia aguda y evolución clínica favorable. Durante la hospitalización desarrolló el patrón electrocardiográfico de Wellens, señalado en la literatura como un hallazgo infrecuente, poco identificado y de pronóstico ominoso. Este patrón electrocardiográfico se detalla en derivadas precordiales, sugiriendo una lesión significativa de una arteria epicárdica principal; la paciente tuvo alteraciones electrocardiográficas similares en las derivadas laterales altas, en quien se confirmó el compromiso de bifurcación coronaria no descrita previamente en este escenario

Complicaciones cardiovasculares en gestante con linfoma primario mediastinal de células B

A 26-year-old pregnant woman with 29 weeks of gestational age reported two months of cough, dyspnea, orthopnea, and palpitations. Chest tomography revealed a 10x12cm solid mass in the right lung. Echocardiography showed that the tumor compromised the right atrium and ventricle, and was diagnosed by transcutaneous biopsy as primary mediastinal B-cell lymphoma (PMCBL). The patient presented 2:1 atrial flutter, sinus bradycardia, and ectopic atrial bradycardia. Due to the rapid poor evolution, it was decided to terminate the pregnancy by cesarean section and start chemotherapy, after which the cardiovascular complications resolved. PCML is a very rare lymphoma that can affect pregnant women in any trimester, its symptoms are related to its rapid growth and compromise of the heart, causing various cardiovascular manifestations (heart failure, pericardial effusion, cardiac arrhythmias). PCMLC is characteristically chemosensitive and has a good prognosis.Gestante de 26 años con 29 semanas de edad gestacional, refirió 2 meses de tos, disnea, ortopnea y palpitaciones. La tomografía de tórax reveló una masa sólida de 10x12 cm en el pulmón derecho; la ecocardiografía mostró que la tumoración comprometía la aurícula y el ventrículo derecho; mediante biopsia transcutánea se diagnosticó linfoma primario mediastinal de células B (LPMCB). La paciente presentó flutter auricular 2:1, bradicardia sinusal y bradicardia auricular ectópica; por la rápida y mala evolución se decidió el término de la gestación por cesárea y el inicio de quimioterapia, posterior a la cual las complicaciones cardiovasculares resolvieron. El LPMCB es un linfoma muy raro que puede afectar gestantes en cualquier trimestre, sus síntomas están relacionados con su rápido crecimiento y comprometen el corazón provocando diversas manifestaciones cardiovasculares (insuficiencia cardíaca, efusión pericárdica, arritmias cardiacas). El LPMCB es característicamente quimiosensible y de buen pronóstico