SpaceART SpaceWire Sniffer for Link Monitoring: A Complete Communication Analysis in a Time-Constrained Test Scenario.

The on-board communication standard adopted in current generation space missions of the European Space Agency, and many other agencies as well, is SpaceWire (SpW). In a SpW network, data are exchanged as well-formed packets, whose structure offers low packet overhead and allows developers to tailor their implementation for SpW applications. The development of SpW-compliant devices requires a specific set of test instruments, namely Electrical Ground Support Equipment (EGSE), to verify the correct functionality of SpW units under test. An example of a SpW EGSE is the SpaceART EGSE Emulator, an EGSE for generation and processing of SpW packets for a time-constrained use-case scenario. This EGSE has been developed to address a mission-related SpW communication between a device and an Instrument Control Unit (ICU). It has allowed the generation and processing of specific SpW packets, which cannot be provided by the mostly used general-purpose SpW EGSEs. In this scope, the SpaceART SpW Sniffer, a SpW link analyser for unobtrusive monitoring of SpW link, has been employed to run a comprehensive set of tests and provide further information on the considered scenario. The SpaceART EGSE Emulator-ICU communication has been thoroughly tested through the SpaceART SpW Sniffer, unobtrusively analysing the exchanged data and allowing to assess the compliance with the defined time constraints from an external point of view. The use of the Sniffer has been crucial for testing the on-board communication, providing important support for the success of the mission employing the tested ICU.

A Complete EGSE Solution for the SpaceWire and SpaceFibre Protocol Based on the PXI Industry Standard.

This article presents a complete test equipment for the promising on-board serial high-speed SpaceFibre protocol, published by the European Committee for Space Standardization. SpaceFibre and SpaceWire are standard communication protocols for the latest technology sensor devices intended for on-board satellites and spacecrafts in general, especially for sensors based on image acquisition, such as scanning radiometers or star-tracking devices. The new design aims to provide the enabling tools to the scientific community and the space industry in order to promote the adoption of open standards in space on-board communications for current- and future-generation spacecraft missions. It is the first instrument expressly designed for LabVIEW users, and it offers tools and advanced features for the test and development of new SpaceFibre devices. In addition, it supports the previous SpaceWire standard and cross-communications. Thanks to novel cutting-edge design methods, the system complex architecture can be implemented on natively supported LabVIEW programmable devices. The presented system is highly customizable in terms of interface support and is provided with a companion LabVIEW application and LabVIEW Application Programming Interface (API) for user custom automated test-chains. It offers real-time capabilities and supports data rates up to 6.25 Gbps.The proposed solutions is then fairly compared with other currently available SpaceFibre test equipment. Its comprehensiveness and modularity make it suitable for either on-board device developments or spacecraft system integrations.

Self-expandable metal stents for malignant colonic obstruction: data from a retrospective regional SIED-AIGO study.

BACKGROUND: Self-expandable metal stents are a non-surgical option for the treatment of symptomatic malignant colorectal obstruction as palliative treatment or as a bridge to surgery. AIMS: To report data from a regional study on self-expandable metal stent (SEMS) placement for malignant colorectal obstruction. METHODS: Two hundred and four patients (male 54.9%, mean age of 69.5 ± 14.2) were retrospectively evaluated and data on technical and clinical success, and complications, were analyzed. RESULTS: Technical and clinical success rates were 99% and 94.6% respectively, with 36.7% treated on an emergency basis and 63.3% electively. Palliative treatment was administered to 70.1%, and as a bridge to surgery for 29.9%. Complications were 17 neoplastic ingrowths, 10 stent migrations, and 4 perforations. Palliative treatment was associated with a higher risk of stent ingrowth (p=0.003), and chemotherapy with a lower risk of stent ingrowth (p=0.009). CONCLUSION: This regional study, although it has certain limitations, confirms the positive role of self-expandable metal stents in the treatment of symptomatic malignant colorectal obstruction, and that chemotherapy decreases the risk of ingrowth.

[Treatment with self-expanding metallic enteral stents in occlusion caused by neoplastic stenosis of the sigmoid and rectum]. / Il trattamento con enterostents autoespansibili metallici nelle occlusioni da stenosi neoplastiche del sigma-retto.

From January 1999 to today 5 patients have been treated with self-expanding enteral stents for low intestinal occlusion in our General and Emergency Surgery Department. The patients' ages ranged from 75 to 90 years. Their general clinical condition was precarious and the emergency surgical treatment necessary was at very high risk. After a brief period of clinical monitoring the patients were submitted to a colonoscopy which revealed a tight neoplastic stenosis in the lowest portion of the colon. Self-expanding enteral stents measuring 9 by 20 mm were implanted in 4/5 patients, while, in the fifth patient, in view of the extent of the cancer, an oesophageal enteral stent measuring 12 by 23-28 mm was used. Over the following 24 hours we observed canalization and consequent disocclusion of the colorectum. It was thus possible to readjust the altered metabolic parameters, improve the respiratory and circulatory compliance and begin the study and the staging of the malignancy. Only two patients in acceptable general condition were submitted to radical surgery, while the other three were referred to our oncological radiotherapy centre. On the basis of this preliminary study we believe that in given clinical conditions and in a situation of emergency the use of self-expanding enteral stents, when indicated, is the only therapeutic measure capable of avoiding surgery carrying a very high risk and of creating the basis for appropriate, in-depth study of the cancer. In addition, it enables a better balance to be restored in the patient's general condition.