The use of a double side mu -strip silicon crystal for X-ray detection is investigated. The detector is 300 mu m thick and the read-out pitch is 100 mu m for both sides. It operates in capacitive ...charge division mode by means of floating strips between read-out strips. The detector is irradiated by /sup 241/Am and /sup 109/Cd sources. Different zones within the 100- mu m read-out pitch are individually exposed. The following characteristics are studied as a function of the impact point of the photon: (a) the charge collection mechanism; (b) the relative detection efficiency; (c) the energy resolution; and (d) the spatial resolution. The absolute efficiency of the detector is measured at three energy values.< >
Double-sided microstrip silicon crystals are tested as detectors for X-rays in the diagnostic energy range (10-100 keV) for digital radiography. An analog-to-digital converter (ADC) and CAMAC-based ...acquisition system is developed to study the imaging capabilities of a silicon mu strip detector with 100- and 200- mu m read-out pitch. The first images of submillimeter high contrast phantoms obtained with an X-ray mammography tube operating at high flux density are presented.< >
We developed a new telediagnosis system to securely transmit high-quality endoscopic moving images over the Internet in real time. This system would enable collaboration between physicians seeking ...advice from endoscopists separated by long distances, to facilitate diagnosis.
We adapted a new type of digital video streaming system (DVTS) to our teleendoscopic diagnosis system. To investigate its feasibility, we conducted a two-step experiment. A basic experiment was first conducted to transmit endoscopic video images between hospitals using a plain DVTS. After investigating the practical usability, we incorporated a secure and reliable communication function into the system, by equipping DVTS with "TCP2", a new security technology that establishes secure communication in the transport layer. The second experiment involved international transmission of teleendoscopic image between Hawaii and Japan using the improved system.
In both the experiments, no serious transmission delay was observed to disturb physicians' communications and, after subjective evaluation by endoscopists, the diagnostic qualities of the images were found to be adequate. Moreover, the second experiment showed that "TCP2-equipped DVTS" successfully executed high-quality secure image transmission over a long distance network.
We conclude that DVTS technology would be promising for teleendoscopic diagnosis. It was also shown that a high quality, secure teleendoscopic diagnosis system can be developed by equipping DVTS with TCP2.
Medical telecare services' designing and redesigning still remains a challenging issue since it often depends on how a number of socio-technological issues are framed. This work has two key ...objectives; the former is to theoretically analyze the nature of a telecare environment by developing a model that reveals potential areas of analysis and the latter is to support designing and redesigning medical telecare services by formulating a strategy as well as a number of 'state of the art' guidelines.
We have extended Leavitt's diamond to develop a model capable of accurately reflecting the telecare environment building dimensions as well as their interactions. This model depends on the i) technology, ii) collaborators, iii) tasks, iv) structure, v) social forces, and the vi) procedure dimensions. Taking this model as a core element we have proposed a service designing and redesigning strategy formulating, in parallel, six scalable dimension-oriented guidelines.
During the two-year period (2003-2005) an enormous amount of data was collected (by active participating in two EU projects, by conducting semistructured interviews, by performing onsite observations as well as by reviewing 78 previous projects) and classified, structuring six guidelines. These guidelines can be considered as the 'state of the art' to support future services' design and redesign.
This work considering the telecare environment as a multi-dimensional, operational organization has put the focus on accurate telecare services' design and redesign. The parameters are not limited, by any means, and are drawn from experience of designing services in a variety of telecare domains. The optimal parameter combination must be chosen according to the aim of each telecare procedure. Further research is needed to determine the minimum parameters to support telecare service design.
Radiation therapy is one of the techniques most commonly used in the treatment of various types of tumors. The microbeam radiation therapy (MRT) is a very promising variant, which exploits the ...property that tissues can tolerate high doses of radiation in small volumes. The effectiveness of MRT is well represented by the peak-to-valley dose ratios (PVDRs), which are one of the crucial parameters associated with the outcome of the treatment. In this study, we investigate on the factors that influence PVDRs, such as different beam energies and geometries. MRT experiments typically employ rectangular (planar) microbeams of different sizes, but, for convenience of analysis, preliminary computations have been performed also using arrays of cylindrical microbeams. This work shows that the shape of the impinging irradiation field largely influences the dose distribution. It highlights that a bundle of larger microbeams, with a small separation, produces more scattered radiation and therefore lower PVDRs. The study of how dose distributions vary with different setups and irradiation parameters is an essential step in enhancing the comparability of experimental data and simulation results.
The aim of this paper is to analyse telemedicine as a new means to improve health care accessibility.
A case study design was used to understand how medical specialists perceived, made sense of, and ...appropriated a teleconsultation system.
The technology was used neither in the manner nor to the extent anticipated by its designers. A fundamental modification to the traditional medical consultation process has emerged. Unable to be used as a substitute to the traditional medical consultation process, the teleconsultation system imposes a greater burden on the shoulders of participating physicians who, after a few trials, returned to their traditional mode of practice.
Chemical and structural modifications in multilayer liposomes of synthetic phosphatidylcholine induced by γ irradiation are investigated with different techniques. Fluorescence anisotropy of the DPH ...probe and differential scanning calorimetry reveal a broadening of the main lipid transition and the disappearance of pretransition. Fluorescence anisotropy is shown to be higher in the irradiated sample and particularly so at low temperatures. NMR and TLC results show that lysolecithin and palmitic acid are formed with a consequent change in bilayer organization. The possibility that these modifications may account for the permeability variations observed in irradiated natural membranes is discussed.
Radiation therapy is widely used in the treatment of very different types of cancer. Recent developments in this field are aiming at delivering high doses to the target volume while sparing the ...surrounding healthy tissues. The microbeam radiation therapy (MRT) is a new kind of radiotherapy which could be used for treating infantile brain tumors, as other kinds of radiotherapy would be extremely dangerous to the normal brain development. MRT is carried out using an array of parallel microbeams of synchrotron-wiggler-generated X-rays. In this work, Monte Carlo simulations using the Geant4 toolkit are carried out to estimate the dose deposition on a 20-cm-diameter, 20-cm-long cylindrical PMMA phantom, mimicking an infantile head. A set of physics processes is implemented in Geant4 to extend the range of validity of electromagnetic interactions down to 250 eV. The dose distribution in MRT is computed to prepare the treatment planning of preclinical trials. Primary photon histories are simulated for the different experimental setups, scoring the dose in cylindrical shells. We used cylindrical monoenergetic microbeams of 50, 100 and 150 keV and one microbeam with energies sampled from the measured spectrum at the ESRF ID17 beamline. The depth- and lateral-dose profiles have been studied, and for a few typical cases, the simulation results have been compared with those obtained with other codes.
Decision Support Telemedicine Systems (DSTS) are at the intersection of two disciplines: tele-medicine and clinical decision support systems (CDSS). The objective of this paper is to provide a set of ...characterizing properties for DSTSs. This characterizing property set (CPS) can be used for typing, classifying and clustering DSTSs.
We performed a systematic keyword-based literature search to identify candidate-characterizing properties. We selected a subset of candidates and refined them by assessing their potential in order to obtain the CPS.
The CPS consists of 14 properties, which can be used for the uniform description and typing of applications of DSTSs. The properties are grouped in three categories that we refer to as the problem dimension, process dimension, and system dimension. We provide CPS instantiations for three prototypical applications.
The CPS includes important properties for typing DSTSs, focusing on aspects of communication for the telemedicine part and on aspects of decisionmaking for the CDSS part. The CPS provides users with tools for uniformly describing DSTSs.
