A review of content-based image retrieval systems in medical applications—clinical benefits and future directions

(1) Whereas the objectives of the Community, as laid down in the Treaty, as amended by the Treaty on European Union, include creating an ever closer union among the peoples of Europe, fostering closer relations between the States belonging to the Community, ensuring economic and social progress by common action to eliminate the barriers which divide Europe, encouraging the constant improvement of the living conditions of its peoples, preserving and strengthening peace and liberty and promoting democracy on the basis of the fundamental rights recognized in the constitution and laws of the Member States and in the European Convention for the Protection of Human Rights and Fundamental Freedoms;

Some Preliminary Comments on the DIRECTIVE 95/46/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 24 October 1995 on the protection of individuals with regard to the processing of personal data and on the free movement of such data.

A database design methodology is defined for the design of large relational databases. First, the data requirements are conceptualized using an extended entity-relationship model, with the extensions being additional semantics such as ternary relationships, optional relationships, and the generalization abstraction. The extended entity-relationship model is then decomposed according to a set of basic entity-relationship constructs, and these are transformed into candidate relations. A set of basic transformations has been developed for the three types of relations: entity relations, extended entity relations, and relationship relations. Candidate relations are further analyzed and modified to attain the highest degree of normalization desired.The methodology produces database designs that are not only accurate representations of reality, but flexible enough to accommodate future processing requirements. It also reduces the number of data dependencies that must be analyzed, using the extended ER model conceptualization, and maintains data integrity through normalization. This approach can be implemented manually or in a simple software package as long as a "good" solution is acceptable and absolute optimality is not required.

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A logical design methodology for relational databases using the extended entity-relationship model

A system and method for maintaining security in a distributed computing environment comprises a policy manager located on a server for managing and distributing a security policy, and an application guard located on a client for managing access to securable components as specified by the security policy. In the preferred embodiment, a global policy specifies access privileges of the user to securable components. The policy manager may then preferably distribute a local client policy based on the global policy to the client. An application guard located on the client then manages access to the securable components as specified by the local policy.

System and method for maintaining security in a distributed computer network

Guyatt G, Rennie D, editors and The Evidence-Based Medicine Working Group. Users' guides to the medical literature. A manual for evidence-based clinical practice. Chicago: AMA Press, 2002



The JAMA series on how to use the medical literature has been expanded and put into book and CD-ROM format. The Evidence-Based Medicine Working Group along with editors Gordon Guyatt and Drummond Rennie have provided practitioners with a valuable resource for evaluating evidence relevant to their practice. The authors of this “how to” book have made certain that it includes challenges to all levels of users of evidence, from beginners to experts. The material is presented in 3 formats: a 700 page manual for evidence-based practice (EBP) (Manual) that is thorough and comprehensive; a 440 page pocket version of the essentials of EBP (Essentials) that provides an indepth discussion of the basics; and a hyperlinked CD-ROM that contains the contents of the Manual and is included with both hardcopy versions. The Essentials book is small enough to keep in a large pocket, although the print is small and may be difficult for really tired eyes to read. The Manual …

https://ebn.bmj.com/content/ebnurs/5/1/8.full.pdf

Users' Guides to the Medical Literature

We discuss the integration of contextual information with team-based access control. The TMAC model was formulated by Thomas in [1] to provide access control for collaborative activity best accomplished by teams of users. In TMAC, access control revolves around teams, where a "team" is an abstraction that encapsulates a collection of users in specific roles and collaborating with the objective of accomplishing a specific task or goal. Users who belong to a team are given access to resources used by a team. However, the effective permissions of a user are always derived from permission types defined for roles that the user belongs to. TMAC is an example of what we call "active security models". These models are aware of the context associated with an ongoing activity in providing access control and thus distinguish the passive concept of permission assignment from the active concept of context-based permission activation. The ability to integrate contextual information allows models such as TMAC to be flexible and express a variety of access policies that can provide tight and just-in-time permission activation.

Flexible team-based access control using contexts

In many health care information systems medical images are an important part of the multimedia medical patient record. Most of the work on multimedia medical images security until now has focused on cryptographic approaches. While valuable, cryptography is not enough to control access to medical images. Therefore additional protection approaches should be applied at a higher level. Role-based access control (RBAC) is a good candidate to provide access control in a multimedia medical image database system. Roles accurately describe which types of people need to access to certain types of objects. However, in a multimedia medical image database system, specifications of image access rights are often content and context-dependent as well as time-dependent. Unfortunately, RBAC cannot be used to handle the above requirements. In this paper we describe an extended role-based access control model by considering, in the specification of the Role-Permission relationship phase, the constraints which must be satisfied in order for the holders of the permission to use those permissions. The use of constraints allows role-based access control to be tailored to specify very fine-grained, flexible, content, context and time-based access control policies. The proposed access control model preserves the advantages of scaleable security administration that RBAC-style models offer and yet offers the flexibility to specify complex access restrictions based on the semantic content of the images, the attributes of the user accessing the image, the relationship between the user and the patient whose images are to be accessed and the time. The description of an access control algorithm and a system architecture for a secure medical image DBMS are also presented.

A flexible content and context-based access control model for multimedia medical image database systems

This work examines the effect of ink composition on steady‐state and time‐dependent behavior in simple shear, as well as on extensional flow behavior. The inks studied were formulated to represent a spectrum of compositions typical of North American news inks. Hydrocarbon pitch, a common dispersant, is found to lower the viscosity at low shear rates in simple shear and to cause a dramatic drop in the extensional stress in a uniaxial stretching test. The addition of a commercial resin commonly found in lithographic inks increased both the viscosity in simple shear and the extensional stress. With respect to time‐dependent behavior, not only is the duration of the shearing of an ink important but also the direction of repeated shear pulses and the time interval between such pulses. The first normal stress difference was found to be negative in certain shear rate ranges. The shear stress‐shear rate relationship of the inks examined has been successfully described by a four‐parameter model.

Rheological Properties of News Inks

BACKGROUND: Clinical information systems frequently use intranet and Internet technologies. However these technologies have emphasized sharing and not security, despite the sensitive and private nature of much health information. Digital certificates (electronic documents which recognize an entity or its attributes) can be used to control access in clinical intranet applications.

OBJECTIVES: To outline the need for access control in distributed clinical database systems, to describe the use of digital certificates and security policies, and to propose the architecture for a system using digital certificates, cryptography and security policy to control access to clinical intranet applications.

METHODS: We have previously developed a security policy, DIMEDAC (Distributed Medical Database Access Control), which is compatible with emerging public key and privilege management infrastructure. In our implementation approach we propose the use of digital certificates, to be used in conjunction with DIMEDAC.

RESULTS: Our proposed access control system consists of two phases: the ways users gain their security credentials; and how these credentials are used to access medical data. Three types of digital certificates are used: identity certificates for authentication; attribute certificates for authorization; and access-rule certificates for propagation of access control policy. Once a user is identified and authenticated, subsequent access decisions are based on a combination of identity and attribute certificates, with access-rule certificates providing the policy framework.

CONCLUSIONS: Access control in clinical intranet applications can be successfully and securely managed through the use of digital certificates and the DIMEDAC security policy.

 [J Med Internet Res 2001;3(1):e9]

Access control based on attribute certificates for medical intranet applications.

A reliability model for a health care domain based on requirement analysis at the early stage of design of regional health network (RHN) is introduced. RHNs are considered as systems supporting the services provided by health units, hospitals, and the regional authority. Reliability assessment in health care domain constitutes a field-of-quality assessment for RHN. A novel approach for predicting system reliability in the early stage of designing RHN systems is presented in this paper. The uppermost scope is to identify the critical processes of an RHN system prior to its implementation. In the methodology, Unified Modeling Language activity diagrams are used to identify megaprocesses at regional level and the customer behavior model graph (CBMG) to describe the states transitions of the processes. CBMG is annotated with: 1) the reliability of each component state and 2) the transition probabilities between states within the scope of the life cycle of the process. A stochastic reliability model (Markov model) is applied to predict the reliability of the business process as well as to identify the critical states and compare them with other processes to reveal the most critical ones. The ultimate benefit of the applied methodology is the design of more reliable components in an RHN system. The innovation of the approach of reliability modeling lies with the analysis of severity classes of failures and the application of stochastic modeling using discrete-time Markov chain in RHNs.

George Pangalos

Papers

Flexible team-based access control using contexts

A flexible content and context-based access control model for multimedia medical image database systems

Rheological Properties of News Inks

Access control based on attribute certificates for medical intranet applications.

A Methodology for Reliability Analysis in Health Networks