Navigation filters for Autonomous Underwater Vehicles during geotechnical surveying experiments

This paper describes two navigation filters designed for an Autonomous Underwater Vehicle (AUV) for geotechnical surveying. Both a Luenberger observer for a kinematic model of the vehicle as well as an extended Kalman filter for its dynamic model are addressed. The filters allow to fuse information coming from a Global Positioning System (GPS), a compass, a gyro, a depth meter, and acoustic based range measurements. A thruster model mapping low level actuator commands to vehicle surge velocity is also exploited in the design. The performances of both filters have been compared using the experimental data collected during the H2020 WiMUST (Widely scalable Mobile Underwater Sonar Technology) project experiments

CMOS-Compatible Room-Temperature Rectifier Toward Terahertz Radiation Detection

In this paper, we present a new rectifying device, compatible with the technology of CMOS image sensors, suitable for implementing a direct-conversion detector operating at room temperature for operation at up to terahertz frequencies. The rectifying device can be obtained by introducing some simple modifications of the charge-storage well in conventional CMOS integrated circuits, making the proposed solution easy to integrate with the existing imaging systems. The rectifying device is combined with the different elements of the detector, composed of a 3D high-performance antenna and a charge-storage well. In particular, its position just below the edge of the 3D antenna takes maximum advantage of the high electric field concentrated by the antenna itself. In addition, the proposed structure ensures the integrity of the charge-storage well of the detector. In the structure, it is not necessary to use very scaled and costly technological nodes, since the CMOS transistor only provides the necessary integrated readout electronics. On-wafer measurements of RF characteristics of the designed junction are reported and discussed. The overall performances of the entire detector in terms of noise equivalent power (NEP) are evaluated by combining low-frequency measurements of the rectifier with numerical simulations of the 3D antenna and the semiconductor structure at 1 THz, allowing prediction of the achievable NEP

Terahertz rectifyier for integrated image detector

We present a new CMOS compatible direct conversion terahertz detector operating at room temperature. The rectenna consists in a truncated conical helix extruded from a planar spiral and connected to a nanometric metallic whisker at one of its edges. The whisker reaches the semiconductor substrate that constitutes the antenna ground plane. The rectifying device can be obtained introducing some simple modifications of the charge storage well in conventional CMOS APS devices, making the proposed solution easy to integrate with existing imaging systems. No need of scaling toward very scaled and costly technological node is required, since the CMOS only provides the necessary integrated readout electronics. On-wafer measurements of RF characteristics of the designed rectifying junction are reported and discussed

Metastatic tumors to the stomach: clinical and endoscopic features.

AIM: To evaluate the clinical and endoscopic patterns in a large series of patients with metastatic tumors in the stomach. METHODS: A total of 64 patients with gastric metastases from solid malignant tumors were retrospectively examined between 1990 and 2005. The clinicopathological findings were reviewed along with tumor characteristics such as endoscopic pattern, location, size and origin of the primary sites. RESULTS: Common indications for endoscopy were anemia, bleeding and epigastric pain. Metastases presented as solitary (62.5%) or multiple (37.5%) tumors were mainly located in the middle or upper third of stomach. The main primary metastatic tumors were from breast and lung cancer and malignant melanoma. CONCLUSION: As the prognosis of cancer patients has been improving gradually, gastrointestinal (GI) metastases will be encountered more often. Endoscopic examinations should be conducted carefully in patients with malignancies, and endoscopic biopsies and information on the patient's clinical history are useful for correct diagnosis of gastric metastases

A case of coffee-ground emesis in an elderly patient

KEY CLINICAL MESSAGE: Black esophagus is an exceeding rare disorder with a multifactorial etiology. Clinical presentation is generally related to upper gastrointestinal bleeding. Diagnosis is based on endoscopic images. Overall mortality is largely related to the underlying medical condition

Polypoid vascular malformation of the small intestine.

A 56-year-old man underwent capsule endoscopy because of obscure GI bleeding. Capsule endoscopy showed a pink and somewhat nodular polypoid lesion of the small bowel partially obstructing the intestinal lumen (A). The patient underwent an ileal resection and the operative specimen showed loss of mucosal folds and the presence of an erythematous area with a polypoid formation of 3.5 × 3 cm (B). Histologic examination revealed the presence of numerous ectatic thin-walled blood vessels and a small number of thick-walled vessels in the submucosa (C and D, arrows; H&E, orig. mag. ×4), surrounded by hypertrophic muscularis mucosae and a chronic inflammatory infiltrate that infiltrated the muscularis propria; the diagnosis of polypoid angiodysplasia was suggested. There has been no recurrence of GI bleeding 14 months after the ileal resection

Laparoscopic Cholecystectomy with a Mixed Approach in a Patient with Kartagener Syndrome: Technical Report and Review of Literature

Kartagener syndrome (KS) is a rare autosomal recessive disease. The disease is characterized by three typical symptoms: chronic sinusitis, situs viscerum inversus (SVI), and bronchiectasis. The laparoscopic cholecystectomy (LC) is the standard procedure in most cases of cholelithiasis, but in SVI patients it can be difficult, especially for right-handed surgeons. We report the case of a 24-year-old female affected by KS, presenting with a history of symptomatic cholelithiasis. Ultrasound and magnetic resonance cholangiopancreatography confirmed SVI totalis and cholelithiasis. The patient underwent a laparoscopic cholecystectomy by a right-handed surgeon performed with a mixed approach without complications. Laparoscopic cholecystectomy in SVI patients can be a safe and reliable technique especially for a left-handed surgeon. The described technique is also easy for a right-handed surgeon. However, it is considered a technically challenging procedure and often requires technical modification