PoseiDRONE: design of a soft-bodied ROV with crawling, swimming and manipulation ability

The design concept and development of a multi-purpose, underwater robot is presented. The final robot consists of a continuum composed for 80% of its volume of rubber-like materials and it combines locomotion (i.e. crawling and swimming) and manipulation capabilities. A first prototype of the robot is illustrated based on the integration of existing prototypes

PoseiDRONE: design of a soft-bodied ROV with crawling, swimming and manipulation ability

The design concept and development of a multi-purpose, underwater robot is presented. The final robot consists of a continuum composed for 80% of its volume of rubber-like materials and it combines locomotion (i.e. crawling and swimming) and manipulation capabilities. A first prototype of the robot is illustrated based on the integration of existing prototypes

Complication of nasal piercing by Staphylococcus aureus endocarditis: a case report and a review of literature

Body piercing, a growing trend especially in young people, is often complicated by severe infections. We present a case of acute bacterial endocarditis by Staphylococcus aureus complicated by multiple cerebral, kidney, spleen embolisms in a young girl, with no known previous cardiac abnormalities, following the piercing of nasal septum. This case highlights the importance of education of patients with and without structural heart disease to the potential dangerous and even life threatening infectious complications of piercing, and stimulate further discussion on the possibility of antibiotic prophylaxis of such procedures

Flagellate Underwater Robotics at Macroscale: Design, Modeling, and Characterization

Prokaryotic flagellum is considered as the only known example of a biological “wheel,” a system capable of converting the action of rotatory actuator into a continuous propulsive force. For this reason, flagella are an interesting case study in soft robotics and they represent an appealing source of inspiration for the design of underwater robots. A great number of flagellum-inspired devices exists, but these are all characterized by a size ranging in the micrometer scale and mostly realized with rigid materials. Here, we present the design and development of a novel generation of macroscale underwater propellers that draw their inspiration from flagellated organisms. Through a simple rotatory actuation and exploiting the capability of the soft material to store energy when interacting with the surrounding fluid, the propellers attain different helical shapes that generate a propulsive thrust. A theoretical model is presented, accurately describing and predicting the kinematic and the propulsive capabilities of the proposed solution. Different experimental trials are presented to validate the accuracy of the model and to investigate the performance of the proposed design. Finally, an underwater robot prototype propelled by four flagellar modules is presented

Thrust depletion at high pulsation frequencies in underactuated, soft-bodied, pulsed-jet vehicles

In this paper we examine the passive stage in the propulsive cycle of a soft-bodied, pulsed-jet, underwater vehicle and its effect on the resultant thrust. This vehicle consists of an elastic shell which propels itself via the discontinuous expulsion and ingestion of finite slugs of ambient water, resulting in a pulsated routine. The activation routine involves the collapse of the elastic shell via cable transmission and its subsequent passive inflation driven by the elastic energy stored in the strained shell walls. Earlier analysis by the authors have found that the thrust generated at each pulsation depends massively on the resilience of the elastic material which composes the shell. In order to improve the design of these vehicle it is thus necessary to characterize the dynamic behaviour of the elastic shell during its stage of inflation by resorting to a coupled potential flow-elastodynamics model. The results enable to better parametrize the thrust model so far employed for this kind of vehicles and in this way achieve a more rigorous description of the vehicle dynamics for design and control purposes

Percutaneous radiofrequency ablation of hepatocellular carcinoma in cirrhosis: Analysis of complications in a single centre over 20 years

Objective: To report on our 20 years' experience on complications after radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) in patients with cirrhosis. Methods: From 1994 to 2014, 1787 RFA procedures were performed percutaneously in 1162 patients with cirrhosis (852 Child A and 310 Child B) with HCC nodules (1.2-7 cm), prothrombin time ≥50%, platelet count of 50.000mm3 and total bilirubin ranging from 0.80 to 4.5mgdl21. In 67 patients, RFA was performed on both intraparenchymal HCC nodule and tumour thrombus extended in the main portal vein and/or its branches. Results: Four patients (0.3%) died after RFA. 39 patients (3.2%) changed in Child's class: 26 out of 28 Child A patients with cirrhosis changed to Child B and 2 changed to Child C class; 11 Child B patients changed to Child C class. On multivariate analysis, the total bilirubin pre-RFA was the only independent risk factor for impairment of liver function and death. Complications were hemoperitoneum, abscess and intrahepatic haematoma. Conclusion: RFA of HCC in patients with cirrhosis is safe, even in case of invasion of the portal venous system. Functional liver reserve should be strictly monitored, mainly when pre-RFA total bilirubin value is ≥2.5mgdl21. The study was approved by our institutional review board. Advances in knowledge: The total bilirubin value ≥2.5mgdl21 represents the main marker of functional liver reserve that predicts decompensation of liver cirrhosis in patients undergoing RFA for HCC

Acute Hepatitis E Mimicking a Flare of Disease in a Patient with Chronic Autoimmune Hepatitis

Acute hepatitis E is becoming increasingly recognised in Europe with up to 40% of the population in Southern France being exposed to the virus, which is harboured in pigs. Patients with known liver disease may present with acute hepatitis E and present a diagnostic challenge. For example patients with autoimmune hepatitis (AIH) who are immunosuppressed and contract hepatitis E may be at increased risk of developing chronicity due to concurrent immunosuppression. Importantly, the diagnosis may be missed with the infection misdiagnosed as an autoimmune flare, and immunosuppression increased by the attending physician, thus enhancing the risk of chronicity of infection leading to progressive liver injury in immunocompromised patients.We report a case of acute hepatitis E in a patient with AIH and discuss the features that helped us differentiating it from an autoimmune flare