Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
Publications

2013

Kidney Targeting and Puncturing During Percutaneous Nephrolithotomy: Recent Advances and Future Perspectives

Authors
Rodrigues, PL; Rodrigues, NF; Fonseca, J; Lima, E; Vilaca, JL;

Publication
JOURNAL OF ENDOUROLOGY

Abstract
Background and Purpose: Precise needle puncture of the kidney is a challenging and essential step for successful percutaneous nephrolithotomy (PCNL). Many devices and surgical techniques have been developed to easily achieve suitable renal access. This article presents a critical review to address the methodologies and techniques for conducting kidney targeting and the puncture step during PCNL. Based on this study, research paths are also provided for PCNL procedure improvement. Methods: Most relevant works concerning PCNL puncture were identified by a search of Medline/PubMed, ISI Web of Science, and Scopus databases from 2007 to December 2012. Two authors independently reviewed the studies. Results: A total of 911 abstracts and 346 full-text articles were assessed and discussed; 52 were included in this review as a summary of the main contributions to kidney targeting and puncturing. Conclusions: Multiple paths and technologic advances have been proposed in the field of urology and minimally invasive surgery to improve PCNL puncture. The most relevant contributions, however, have been provided by the application of medical imaging guidance, new surgical tools, motion tracking systems, robotics, and image processing and computer graphics. Despite the multiple research paths for PCNL puncture guidance, no widely acceptable solution has yet been reached, and it remains an active and challenging research field. Future developments should focus on real-time methods, robust and accurate algorithms, and radiation free imaging techniques.

2013

A secure RBAC mobile agent access control model for healthcare institutions

Authors
Santos Pereira, C; Augusto, AB; Cruz Correia, R; Correia, ME;

Publication
Proceedings - IEEE Symposium on Computer-Based Medical Systems

Abstract
In medical organizations, healthcare providers need to have fast access to patients' medical information in order to make accurate diagnoses as well as to provide appropriate treatments. Efficient healthcare is thus highly dependent on doctors being provided with access to patients' medical information at the right time and place. However it frequently happens that critical pieces of pertinent information end up not being used because they are located in information systems that do not inter-operate in a timely manner. Unfortunately the standard operational mode for many healthcare applications, and even healthcare institutions, is to be managed and operated as isolated islands that do not share information in an efficient manner. There are many reasons that contribute to this grim state of affairs, but what interests us the most is the lack of enforceable security policies for systems interoperability and data exchange and the existence of many heterogeneous legacy systems that are almost impossible to directly include into any reasonable secure interoperable workflow. In this paper we propose a RBAC mobile agent access control model supported by a specially managed public key infrastructure for mobile agent's strong authentication and access control. Our aim is to create the right means for doctors to be provided with timely accurate information, which would be otherwise inaccessible, by the means of strongly authenticated mobile agents capable of securely bridging otherwise isolated institutional eHealth domains and legacy applications. © 2013 IEEE.

2013

Free daily newspapers: too strong incentives to print?

Authors
Correia da Silva, J; Resende, J;

Publication
PORTUGUESE ECONOMIC JOURNAL

Abstract
A free daily newspaper distributes news to readers and sells ad-space to advertisers, having private information about its audience. For a given number of distributed copies, depending on the type of audience (favorable or unfavorable), the newspaper may either have a large readership or a small readership. A large readership provides a greater return to advertisers, because ads are visualized by more people. A favorable audience has also the advantage of requiring a lower distribution cost (for a given number of distributed copies), because readers are willing to exert more effort to obtain a copy of the free newspaper and are less likely to reject a copy that is handed to them. We find that when the audience is unfavorable, the number of distributed copies and the price of ad-space coincide with those of the perfect information scenario. In contrast, if the audience is favorable, the newspaper prints extra copies to send a credible signal to the advertisers that the audience is favorable. Overprinting is not necessarily welfare-detrimental since readers benefit from the existence of additional copies.

2013

Smart Grid Market Using Joint Energy and Ancillary Services Bids

Authors
Soares, T; Morais, H; Faria, P; Vale, Z;

Publication
2013 IEEE GRENOBLE POWERTECH (POWERTECH)

Abstract
The power systems operation in the smart grid context increases significantly the complexity of their management. New approaches for ancillary services procurement are essential to ensure the operation of electric power systems with appropriate levels of stability, safety, quality, equity and competitiveness. These approaches should include market mechanisms which allow the participation of small and medium distributed energy resources players in a competitive market environment. In this paper, an energy and ancillary services joint market model used by an aggregator is proposed, considering bids of several types of distributed energy resources. In order to improve economic efficiency in the market, ancillary services cascading market mechanism is also considered in the model. The proposed model is included in MASCEM - a multi-agent system electricity market simulator. A case study considering a distribution network with high penetration of distributed energy resources is presented.

2013

Coordinating Storage and Demand Response for Microgrid Emergency Operation

Authors
Gouveia, C; Moreira, J; Moreira, CL; Pecas Lopes, JAP;

Publication
IEEE TRANSACTIONS ON SMART GRID

Abstract
Microgrids are assumed to be established at the low voltage distribution level, where distributed energy sources, storage devices, controllable loads and electric vehicles are integrated in the system and need to be properly managed. The microgrid system is a flexible cell that can be operated connected to the main power network or autonomously, in a controlled and coordinated way. The use of storage devices in microgrids is related to the provision of some form of energy buffering during autonomous operating conditions, in order to balance load and generation. However, frequency variations and limited storage capacity might compromise microgrid autonomous operation. In order to improve microgrid resilience in the moments subsequent to islanding, this paper presents innovative functionalities to run online, which are able to manage microgrid storage considering the integration of electric vehicles and load responsiveness. The effectiveness of the proposed algorithms is validated through extensive numerical simulations.

2013

Physician's awareness of e-prescribing security risks

Authors
Rodrigues, H; Antunes, LFC; Santos, C; Correia, ME; Pinho, TM; Magalhaes, HG;

Publication
Proceedings - IEEE Symposium on Computer-Based Medical Systems

Abstract
New governmental legislation introduced e-prescription as mandatory in the Portuguese health system. This changes consequences were not properly considered, which caused security problems related to patient and prescriber's data, such as digital identity fraud or access to prescriptions history to build clinical profiles. In order to evaluate the e-prescribing software users awareness to those risks, a survey took place, and the results revealed ignorance of certain obligations and procedures of the e-prescribing process. A significant part of doctors are not conscious about where the patient's data is stored neither about the risks related with prescription's information. © 2013 IEEE.

  • 3053
  • 4377