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ABSTRACT: In this work, two novel background correction (BC) methods, along with several commonly used ones, are evaluated regarding noise reduction in eleven two-channel self-versus-self (SVS) hybridizations. The evaluation of each BC method is investigated under the use of four statistical criteria combined into a single measure, the polygon area measure. Overall, our proposed BC approaches perform very well in terms of the proposed measure for most of the cases and provide an improved effect regarding technical noise reduction.
Computers in biology and medicine 11/2011; 42(1):19-29. · 1.27 Impact Factor
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ABSTRACT: The purpose of this study is to introduce a novel empirical iterative algorithm for medical image reconstruction, under the short name ISWLS (image space weighted least squares), which is expected to have image space reconstruction algorithm (ISRA) properties in noise manipulation and weighted least-squares (WLS) acceleration of the reconstruction process. We used phantom data from a prototype small-animal positron emission tomography system and the methods presented here are applied to 2-D sinograms. Further, we assess the performance of the new algorithm by comparing it to the simultaneous version of algebraic reconstruction technique (ART), simultaneous algebraic reconstruction technique (SART), to expectation maximization maximum likelihood (EM-ML), ISRA, and WLS. All algorithms are compared in terms of cross-correlation coefficient, reconstruction time, and contrast-to-noise ratios (CNRs). As it turns out, ISWLS presents higher CNRs than EM-ML, ISRA, and SART for objects of different sizes. Also, ISWLS shows similar performance to WLS during the first iterations but it has better noise manipulation. Finally, ordered subsets ISWLS (OS-ISWLS), the OS version of ISWLS, shows its best performance between the first six-nine iterations. Its behavior seems to be a compromise between OS-ISRA and OS-WLS.
IEEE Transactions on Information Technology in Biomedicine 06/2011; · 1.68 Impact Factor
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ABSTRACT: In this work various methods of parametric elastic models are compared, namely the classical snake, the gradient vector field snake (GVF snake) and the topology-adaptive snake (t-snake), as well as the method of self-affine mapping system as an alternative to elastic models. We also give a brief overview of the methods used. The self-affine mapping system is implemented using an adapting scheme and minimum distance as optimization criterion, which is more suitable for weak edges detection. All methods are applied to glaucomatic retinal images with the purpose of segmenting the optical disk. The methods are compared in terms of segmentation accuracy and speed, as these are derived from cross-correlation coefficients between real and algorithm extracted contours and segmentation time, respectively. As a result, the method of self-affine mapping system presents adequate segmentation time and segmentation accuracy, and significant independence from initialization.
Technology and health care: official journal of the European Society for Engineering and Medicine 01/2011; 19(6):401-13.
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ABSTRACT: The purpose of the present manuscript is to present the advances performed in medicine using a Personalized Decision Support System (PDSS). The models used in Decision Support Systems (DSS) are examined in combination with Genome Information and Biomarkers to produce personalized result for each individual. The concept of personalize medicine is described in depth and application of PDSS for Cardiovascular Diseases (CVD) and Type-1 Diabetes Mellitus (T1DM) are analyzed. Parameters extracted from genes, biomarkers, nutrition habits, lifestyle and biological measurements feed DSSs, incorporating Artificial Intelligence Modules (AIM), to provide personalized advice, medication and treatment.
Engineering in Medicine and Biology Society (EMBC), 2010 Annual International Conference of the IEEE; 10/2010
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ABSTRACT: Autofluorescence bronchoscopy (AFB) has been utilized over the past decade, proving to be a powerful tool for the detection
and localization of premalignant and malignant lesions of the airways. Autofluorescence bronchoscopy is, however, characterized
by low specificity and a high rate of false positive findings (FPFs). The majority of FPFs are due to inflammations, as they
often fluoresce at the same wavelengths with cancer. According to several clinical trials, the percentage of the FPFs is about
30%. In this paper we present an intelligent computing system for the classification of suspicious areas of the bronchial
mucosa, in order to decrease the rate of FPFs, to increase the specificity and sensitivity of AFB and enhance the overall
diagnostic value of the AFB method.
12/2009: pages 1838-1841;
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ABSTRACT: The aim of this work is to estimate the volume of a random shape cavity using distance sensors which transmit on a surface of a sphere, where sensors are mounted in a normal distribution. It is based on a variant method of convex surface volume measurement using triangulation. The innovation in the present work is that the measurements of distances for triangulation are taken from a random point of the cavity, to the inner wall. This method could be applied in cardiac ventricles; ventricles volume is an important hemodynamic factor for heart failure patients. The necessity for a new method of volume measurement by catheterization is more compulsory in the right ventricle due to its shape singularity than in the case of the left ventricle, whose practicable shape helps in easier volume estimation.
Information Technology and Applications in Biomedicine, 2009. ITAB 2009. 9th International Conference on; 12/2009
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ABSTRACT: Public healthcare is a basic service provided by governments to citizens which is increasingly coming under pressure as the European population ages and the ratio of working to elderly persons falls. A way to make public spending on healthcare more efficient is to ensure that the money is spent on legitimate causes. This paper presents the work of the iWebCare project where a flexible, on-line, fraud detection, Web services platform was designed and developed. It aims to help those in the healthcare business, minimize the loss of funds to fraud. The platform is able to detect erroneous or suspicious records in submitted health care data sets, ensuring homogeneity and consistency and promoting awareness and harmonization of fraud detection practices across health care systems in the EU. Critical objectives included, the development of an ontology of health care data associated with semantic rules, implementation and initial population of an ontology and rules repository, development of a fraud detection engine and implementation of a data mining module. The potential impact of this work can be substantial. More money on healthcare mean better healthcare. Living conditions and the trust of citizens in public healthcare will be improved.
Information Technology and Applications in Biomedicine, 2009. ITAB 2009. 9th International Conference on; 12/2009
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ABSTRACT: Recent advances in information and communication technologies permitted the design and development of new patient-centric models for the provision of better health care services and enhancement of patient's self-management. This paper presents a prototype mobile phone application which is being designed to improve the self-management of individuals with Type 1 Diabetes Mellitus (T1DM). The developed application using the Microsoft .Net framework runs on 3G mobile phones. The application consists of five major interfaces for the management of: blood glucose measurements, blood pressure measurements, insulin dosage, food/drink intake and physical activity. Furthermore, the user has the following capabilities i) to keep notes, and ii) in case of an emergency to press a button, in order to transmit immediately his/her position to both an emergency call center, and the attendant physician. It has to be noted, that the above mentioned data are stored locally to the mobile phone, and regularly transmitted via the mobile network to a dedicated hospital web-server. Technical evaluation of the prototype indicates that the use of the mobile network makes feasible the self-management of T1DM.
Information Technology and Applications in Biomedicine, 2009. ITAB 2009. 9th International Conference on; 12/2009
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ABSTRACT: During the last years, need for increased funding for national health services offered to citizens is rising. The reasons are (i) decreased ratio of working population/pensioners, as well as (ii) increase of life expectancy. Thus, high priority should be given to safeguarding the reliable administration of the financial resources devoted to this purpose. This paper describes the application of a "clever" system which can be used by social security bodies (SSBs) and healthcare providers for: (a) Electronic data entry of prescriptions written by doctors to patients, (b) Check of prescriptions against predefined rules entered in the system for errors or possible fraud, reporting all ¿suspicious¿ cases. In addition, an integrated system for administering prescriptions was implemented, that offers the ability to query, view and print data in the format required by the user. The application was designed and implemented using Microsoft Access 2002 relational database system environment. For testing the application, data by the Greek Social Security Body of people working in Healthcare (namely T.S.A.Y.) were used; all personal information was removed.
Information Technology and Applications in Biomedicine, 2009. ITAB 2009. 9th International Conference on; 12/2009
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ABSTRACT: The objective of the present study was the analysis of microarray data from a T-cell leukemia cell line (CCRF-CEM), treated with two different prednisolone concentrations, using four different pre-processing methods, within the Matlab<sup>reg</sup> computing environment. We have compared these methods using hierarchical clustering. The gene expression patterns revealed by hierarchical clustering were used to draw probable conclusions on the question whether resistance to glucocorticoids is inherent or acquired, in this type of cells. Although different algorithmic approaches have concluded different results, the set of genes examined manifested an opposing pattern in their expression profile between low and high prednisolone concentrations. This opposing behavior seems to be related to glucocorticoid receptor-related gene repression or activation, leading to the activation of resistance mechanisms within the cell system studied.
BioInformatics and BioEngineering, 2008. BIBE 2008. 8th IEEE International Conference on; 11/2008
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ABSTRACT: The purpose of this study is to evaluate the average performance of algebraic and statistical iterative reconstruction methods, using phantom data from a prototype small-animal PET system. The algorithms that are being compared are the simultaneous versions of ART (SART) and MART (SMART), EM-ML, ISRA and WLS. The evaluation study was based on reconstructed image quality, as it is derived from visual inspection, normalized profiles, cross-correlation coefficient and CNRs (contrast-to-noise ratios) of specific ROIs (region-of-interest). In general EM-ML and ISRA present similar reconstruction time and minor differences in reconstructed image quality. Slightly superior performances show WLS and SART while SMART is not adequate for reconstruction of PET data.
Bioengineering Conference, 2007. NEBC '07. IEEE 33rd Annual Northeast; 04/2007
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ABSTRACT: Information technology advances have brought forth new challenges in healthcare information management, due to the vast amount of medical data that needs to be efficiently stored, retrieved, and distributed, and the increased security threats that explicitly have to be addressed. The paper discusses the perspectives of digital watermarking in a range of medical data management and distribution issues, and proposes a complementary and/or alternative tool that simultaneously addresses medical data protection, archiving, and retrieval, as well as source and data authentication. The scheme imperceptibly embeds in medical images multiple watermarks conveying patient's personal and examination data, keywords for information retrieval, the physician's digital signature for authentication, and a reference message for data integrity control. Experimental results indicate the efficiency and transparency of the scheme, which conforms to the strict requirements that apply to regions of diagnostic significance
IEEE Transactions on Information Technology in Biomedicine 11/2006; · 1.68 Impact Factor
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ABSTRACT: The implementation of digital watermarking technology in healthcare applications is still in its infancy; however, the benefits of exploring this technology towards secure and efficient health data management are steadily propagated and realized by the research community. The paper presents the architecture of a watermarking software development kit (SDK), which provides multiple watermarking functionality and can be customized according to the targeted medical application, in order to address security of sensitive data, origin and data authentication, image archiving and retrieval. Two use cases of the proposed watermarking SDK are presented, the one involving access to the watermarking engine through a user interface, and the other referring to the case that the engine is embedded into the image acquisition device. The nature of the embeddable information that is applicable in each use case is also described
Engineering in Medicine and Biology Society, 2006. EMBS '06. 28th Annual International Conference of the IEEE; 10/2006
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ABSTRACT: Implementing telemedical solutions has become a trend amongst the various research teams at an international level. Yet, contemporary information access and distribution technologies raise critical issues that urgently need to be addressed, especially those related to security. The paper suggests the use of watermarking in telemedical applications in order to enhance security of the transmitted sensitive medical data, familiarizes the users with a telemedical system and a watermarking module that have already been developed, and proposes an architecture that will enable the integration of the two systems, taking into account a variety of use cases and application scenarios
Engineering in Medicine and Biology Society, 2006. EMBS '06. 28th Annual International Conference of the IEEE; 10/2006
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ABSTRACT: The landscape of healthcare delivery and medical data management has significantly changed over the last years, as a result of the significant advancements in information and communication technologies. Complementary and/or alternative solutions are needed to meet the new challenges, especially regarding security of the widely distributed sensitive medical information. Digital watermarking is a recently established research area with many applications; nevertheless, the potential of this technology to contribute value-added services to medical information management systems has only recently started to be realized by the research community. The paper presents a review of research efforts in the area of medical-oriented watermarking and proposes a wavelet-based multiple watermarking scheme; this scheme aims to address critical health information management issues, including origin and data authentication, protection of sensitive data, and image archiving and retrieval. In accordance with the strict limitations applying to medical images, the scheme allows the definition of a region of interest (ROI) whose diagnostic value is protected, since the only additional information embedded therein aims at integrity control. The robustness of the method is enhanced through a form of hybrid coding, which includes repetitive embedding of BCH encoded watermarks. The experimental results on different medical imaging modalities demonstrate the efficiency and transparency of the watermarking scheme.
Medical & Biological Engineering & Computing 09/2006; 44(8):619-31. · 1.88 Impact Factor
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ABSTRACT: In this paper a 3-D object's/face's caricature recognition system is proposed. An object's-caricature is recognized through a probabilistic fusion procedure. The innovation introduced is that an object's/face's 2-D caricature's views that are taken in 3-D are fused in terms of their contour features. In addition, these features are directly connected to all of the objects and faces stored in our database. A face/object is thus regarded as the output of a detailed probabilistic Bayesian analysis of the views' contours being inter-independent parameters. The features are the object's/face's border pixels that are extracted from low-level edge information. The faces were separated from background clutter using the C.M. for two clusters (background and foreground) for the fist view and then the nearest neighbour classifier. Both kinds of patterns are modelled as distributions, as they are vague due to the non-perfect lighting conditions and different face postures. For all contour features partial hypotheses, expressed as Gaussian probabilistic conditionals were examined in real time, in terms of their plausibility with regard to which object they are most likely connected to. For faces, shoulder noise does not deteriorate the recognition performance as a result of the robust Bayesian reasoning followed. We arrive at a final distribution allocating a certain degree of confidence to a set of the available objects/faces. The objective is three-fold: 1. to recognize a known object/face from a significantly reduced set of all candidate views/faces not presented to the system before, 2. to recognize a strongly altered unknown view that belongs to known object/face, 3. find the best resembling known object /face for a totally unknown object/face that is presented to the system, 4. do all the above with minor training, and with comparable success to systems using complex model parameters distributions. The object features were taken from a camera assuming different lo-
ngitude positions around the unknown object. The faces were taken from the Manchester face database. The applications to forensic science object and person identification are obvious as the system uses very simple characteristics amenable for use with CCTV cameras, fast algorithms and reaches sufficient reliability. An easier expert knowledge integration using probabilistic priors is also provided
Crime and Security, 2006. The Institution of Engineering and Technology Conference on; 07/2006
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ABSTRACT: The formulation of a personal area network (PAN), consisting of a wireless infrastructure of medical sensors, attached to patient's body, and a supervising device carried by them, lays the path for continuous and real-time monitoring of vital signs without discomforting the person in question. This infrastructure enhances the context of remote healthcare services by supporting flexible acquisition of crucial vital signs, while at the same time it provides more convenience to the patient. Aiming at the exploitation of the inherent features and requirements of wireless medical sensor networks, in this paper we focus on the main design guidelines of a low power medium access control (MAC) protocol, designated to support a patient PAN. The proposed protocol intends to improve energy efficiency in such applications and thus is oriented towards the prevention of main energy wastage sources, such as collision, idle listening and power outspending
Engineering in Medicine and Biology Society, 2005. IEEE-EMBS 2005. 27th Annual International Conference of the; 02/2006
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ABSTRACT: Type 1 diabetes mellitus is a chronic disease characterized by blood glucose levels out of normal range due to inability of insulin production. This dysfunction leads to many short- and long-term complications. In this paper, a system for tele-monitoring and tele-management of type 1 diabetes patients is proposed, aiming at reducing the risk of diabetes complications and improving quality of life. The system integrates wireless personal area networks (WPAN), mobile infrastructure, and Internet technology along with commercially available and novel glucose measurement devices, advanced modeling techniques, and tools for the intelligent processing of the available diabetes patients information. The integration of the above technologies enables intensive monitoring of blood glucose levels, treatment optimisation, continuous medical care, and improvement of quality of life for type 1 diabetes patients, without restrictions in everyday life activities
Engineering in Medicine and Biology Society, 2005. IEEE-EMBS 2005. 27th Annual International Conference of the; 02/2006
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ABSTRACT: Beyond its already established wide range of applications, digital watermarking has recently started to gain a foothold in the healthcare sector. The paper discusses the potential of multiple watermarking to address a number of health information management issues, such as protection of sensitive data, origin and data authentication, image archiving and retrieval. A wavelet-based multiple watermarking scheme focusing on these medical-oriented applications is presented; the scheme allows the physician to define a region of interest, whose diagnostic value is explicitly protected throughout the embedding process, since the only additional information inserted therein is for the purpose of integrity control. The rest part of the image casts multiple watermarks conveying the physician's digital signature, patient's sensitive data, and keywords allowing image retrieval. In order to increase data robustness, a form of hybrid coding is applied, which includes repetitive embedding of BCH encoded watermarks
Engineering in Medicine and Biology Society, 2005. IEEE-EMBS 2005. 27th Annual International Conference of the; 02/2006
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ABSTRACT: In the process of developing a wireless networking solution to provide effective field-deployable communications and telemetry support for rescuers during major natural disasters, we are faced with the task of interfacing the multitude of medical and other legacy data collection sensors to the network grid. In this paper, we detail a number of solutions, with particular attention given to the issue of data security. The chosen implementation allows for sensor control and management from remote network locations, while the sensors can wirelessly transmit their data to nearby network nodes securely, utilizing the latest commercially available cryptography solutions. Initial testing validates the design choices, while the network-enabled sensors are being integrated in the overall wireless network security framework
Engineering in Medicine and Biology Society, 2005. IEEE-EMBS 2005. 27th Annual International Conference of the; 02/2006
