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Telecommunication in medicine is becoming increasingly important. This contribution describes a national project in the Netherlands aimed at developing standards for electronic messages and evaluation of cost and benefits of electronic data exchange.
This article reports on the electric network frequency criterion as a means of assessing the integrity of digital audio/video evidence and forensic IT and telecommunication analysis. A brief description is given to different ENF types and phenomena that determine ENF variations. In most situations, to reach a non-authenticity opinion, the visual inspection of spectrograms and comparison with an ENF database are enough. A more detailed investigation, in the time domain, requires short time windows measurements and analyses. The stability of the ENF over geographical distances has been established by comparison of synchronized recordings made at different locations on the same network. Real cases are presented, in which the ENF criterion was used to investigate audio and video files created with secret surveillance systems, a digitized audio/video recording and a TV broadcasted reportage. By applying the ENF Criterion in forensic audio/video analysis, one can determine whether and where a digital recording has been edited, establish whether it was made at the time claimed, and identify the time and date of the registering operation.
Safety of astronauts during long-term space exploration is a priority for NASA. This paper describes efforts to produce Earth-based models for providing expert medical advice when unforeseen medical emergencies occur on spacecraft. These models are Virtual Collaborative Clinics that reach into remote sites using telecommunications and emerging stereo-imaging and sensor technologies.
Health delivery practices are shifting towards home care. The reasons are the better possibilities for managing chronic care, controlling health delivery costs, increasing quality of life and quality of health services and the distinct possibility of predicting and thus avoiding serious complications. For the above goals to become routine, new telemedicine and information technology (IT) solutions need to be implemented and integrated in the health delivery scene, and these solutions need to be assessed through evidence-based medicine in order to provide solid proof for their usefulness. Thus, the concept of contact or call centers has emerged as a new and viable reality in the field of IT for health and telemedicine. In this paper we describe a generic contact center that was designed in the context of an EU funded IST for health project with acronym Citizen Health System (CHS). Since the generic contact center is composed by a number of modules, we shall concentrate in the modules dealing with the communication between the patient and the contact center using mobile telecommunications solutions, which can act as link between the internet and the classical computer telephony communication means. We further elaborate on the development tools of such solutions, the interface problems we face, and on the means to convey information from and to the patient in an efficient and medically acceptable way. This application proves the usefulness of wireless technology in providing health care services all around the clock and everywhere the citizen is located, it proves the necessity for restructuring the medical knowledge for education delivery to the patient, and it shows the virtue of interactivity by means of using the limited, yet useful browsing capabilities of the wireless application protocol (WAP) technology.
Three new dipolar chromophores based on a diaklyaminophenyl donor, a pyrrole auxiliary donor, a thiazole auxiliary acceptor, and strong heterocyclic acceptors have been synthesized. For one of these compounds we have measured a very large non-degenerate two-photon cross section of ca. 1500 GM in the near-IR telecommunications range using a pump-probe technique. Calculations indicate the cross section for degenerate two-photon absorption is likely to be ca. 60% of this value.
A convenient, aqueous-based synthesis of stable HgTe nanocrystals with widely size-tunable room temperature emission between wavelengths of 1.2 to 3.7 mum is demonstrated. By the choice of the thiols, applied as stabilizers, we optimized the growth dynamics, the luminescence quantum yields (up to 40%), and a ligand-exchange procedure, required to transfer the nanocrystals from water to nonpolar organic solvents. The latter is greatly improved and facilitated by the use of mercaptoethylamine as initial stabilizer. The possibility to tune the HgTe nanocrystal sizes from 3 to 12 nm and to control their surface functionalities (hydrophobic and hydrophilic) makes them very promising for the development of infrared optical devices, emitting in the wavelength region between the telecommunications and the molecular vibrations.
Matter and energy cannot be teleported (that is, transferred from one place to another without passing through intermediate locations). However, teleportation of quantum states (the ultimate structure of objects) is possible: only the structure is teleported--the matter stays at the source side and must be already present at the final location. Several table-top experiments have used qubits (two-dimensional quantum systems) or continuous variables to demonstrate the principle over short distances. Here we report a long-distance experimental demonstration of probabilistic quantum teleportation. Qubits carried by photons of 1.3 micro m wavelength are teleported onto photons of 1.55 micro m wavelength from one laboratory to another, separated by 55 m but connected by 2 km of standard telecommunications fibre. The first (and, with foreseeable technologies, the only) application of quantum teleportation is in quantum communication, where it could help to extend quantum cryptography to larger distances.
Digestive endoscopy is currently the main diagnostic procedure for investigation of the digestive tract whenever a digestive disease is suspected. From 1970 to 1985, digestive endoscopy was performed with endoscopes equipped with fiberoptic bundles, whereas the last decade was marked by the development of electronic endoscopes, characterized by the presence of a CCD (charge coupled device) at the tip of the endoscope. Thus the physician looks at a TV screen to control the procedure and examine in detail the gut wall. Endoscopes examine the foregut until the duodenum and the hindgut, up to the three last intestinal loops. When the endoscopic workstation comprises a computer, it is possible to acquire electronic images during the endoscopy and use these images as support of the information about the results of the procedure. These numeric images can then be stored in databases containing text attached to them. Starting with these images, one may expect many developments in the near future that will change the management of the patient with digestive diseases. Physicians will become able to exchange images and text related to one patient or one procedure, although they are equipped with different workstations. Therefore, it is obvious that the information exchanged must be written in a standard format that makes it understandable by all systems. The European Society of Gastrointestinal Endoscopy is a scientific society that groups most of the gastroenterologists in Europe. This society has initiated a research program to develop standards for the exchange of images and text. The Gastrointestinal Endoscopy Applications for Standards in Telecommunication, Education, and Research (GASTER) project intends to implement a multimedia database of endoscopic images based on a standard format of images and a standard terminology for descriptive terms. These standards must be validated by use in different endoscopy units. The database will collect images from these centers that will be linked to the coordinating center through a network based on an integrated services digital network (fast electronic connection). This database will then be used for the development of computer applications. The output of the GASTER project will bring advances at three levels: (1) The physicians will be able to exchange images about the procedures their patients have undergone and will thus obtain more complete information, improving quality of care. They will also benefit from help-to-decision applications based on validated reference images from the database. (2) At the patient level, the quality of care will be improved through a better dissemination of information between the physicians in charge of the patient, thus there is better follow-up of the patient and a decrease in redundant examinations. (3) At the level of national health care systems, the benefit will be a decrease in cost of care due to a better follow-up of the patients, a decrease in redundant examinations, and a faster decision made to treat the patient. The possibility of consulting a database of a scientifically validated images used as reference material will also improve quality control in digestive endoscopy.
Disaster management utilizes diverse technologies to accomplish a complex set of tasks. Despite a decade of experience, few published reports have reviewed application of telemedicine (clinical care at a distance enabled by telecommunication) in disaster situations. Appropriate new telemedicine applications can improve future disaster medicine outcomes, based on lessons learned from a decade of civilian and military disaster (wide-area) telemedicine deployments. This manuscript reviews the history of telemedicine activities in actual disasters and similar scenarios as well as ongoing telemedicine innovations that may be applicable to disaster situations. Emergency care providers must begin to plan effectively to utilize disaster-specific telemedicine applications to improve future outcomes.
The recommendation architecture has been proposed as a system architecture which can enable a system to learn to perform a complex combination of interrelated functions. The capability of a system with the recommendation architecture to learn to manage complex telecommunication backbone networks has been investigated. A network model with a number of nodes and links and carrying realistic but randomly generated traffic was used as the target for the management system. Traffic data taken from the model was used as input to the recommendation architecture system. The traffic data was organized into inputs once every 5 minutes, and the management system organized these inputs into a hierarchy of repetition similarity. It was demonstrated that the outputs of this hierarchy provided information on the condition of the network. This output information was a compressed version of the inputs which correlated with major network conditions.
Cellular radio telecommunication has increased exponentially with many applications to health care reported. The authors attempt to summarize published applications with demonstrated effect on health care, review briefly the rapid evolution of hardware and software standards, explain current limitations and future potential of data quality and security, and discuss issues of safety.
Realtime ultrasound screening was carried out using a medical examination vehicle equipped with a diagnostic ultrasound scanner and a satellite telecommunication system. Screening was performed on 205 residents in a rural community in Japan and consisted of 57 cardiac, 57 abdominal, 60 thyroid and 31 breast ultrasound scans. The resolution of the realtime ultrasound images sent via communications satellite at 1.5 Mbit/s was almost identical to that of the original images taken by the ultrasound scanner. A disorder was diagnosed in 11 (19%) of the cardiac examinations, 28 (49%) of the abdominal, 19 (32%) of the thyroid and 7 (23%) of the breast examinations. Although some technical problems occurred, ultrasound screening by telemedicine appears to be a promising technique for those who live in rural communities.
According to the U.S. Federal Trade Commission, an estimated 22 million Americans used their computers to seek medical information in 1995, making health concerns the sixth most common reason for using the Internet in the United States. Market research firms estimate that the number of people going online for this purpose is growing by 70% annually. Developments in computer technology, the Internet, and wireless and satellite telecommunications have led to major innovations in the nature and delivery of health care that have broad implications for the way people will receive health information and treatment in the future, even allowing health care providers to interact through cyberspace with their patients and other caregivers.
A two-mirror multipass absorption cell that is operated open to the atmosphere from a stratospheric balloon to monitor in situ methane (in the 1.65-microm region) and water vapor (in the 1.39-microm region) with telecommunication laser diodes is described. A small Cassegrain-type telescope is used to couple the cell simultaneously with two near-infrared InGaAsP laser diodes by means of optical fibers. The 1-m cell provides an absorption path length of 56 m. The optical cell was carefully designed to be free of incidental fringing in the 10(-5) absorption range. It is used in combination with a dual-beam detector to obtain a detection limit of 10(-5) absorption units, a large dynamic range of the measurements of many orders of magnitude, and a precision error in the concentration determination of a few percents. The optical arrangement of the cell and its ability to be used to detect in situ trace gas in the stratosphere, in severe environmental conditions, are exposed.
A gas sensor based on quartz-enhanced photoacoustic detection and a fiber-coupled telecommunication distributed-feedback diode laser was designed and characterized for trace NH3 monitoring at a 1.53-microm wavelength (overtone absorption region). Signal and noise dependence on gas pressure were studied to optimize sensor performance. The ammonia concentration resulting in a noise-equivalent signal was found to be 0.65 parts per million by volume with 38-mW optical excitation power and a lock-in amplifier time constant of 1 s. This corresponds to a normalized absorption sensitivity of 7.2 x 10(-9) cm(-1) W/Hz1/2, comparable with detection sensitivity achieved in conventional photoacoustic spectroscopy. The sensor architecture can be the basis for a portable gas analyzer.
The impact of the interferometer optical path difference (OPD) speed profile on the spectrum, derived through the use of Fourier-transform spectrometry (FTS), of a synchronous optical network (SONET) signal is found. The SONET signal carries high-speed data traffic. It also may be modulated by low-frequency intensity or frequency modulation. It is found that the SONET header, high-speed data traffic and low-frequency modulation all manifest themselves as artifacts in the FTS-derived spectrum of the SONET signal. It is shown that a nonconstant OPD speed profile can smooth out these artifacts, making it unlikely that they will be mistaken for carrier signal peaks. However, it is found that smoothing out these artifacts lessens the achievable dynamic range of the FTS instrument in the frequency range of interest, the International Telecommunications Union common (C) and long (L) bands.
Experimental results and a discussion on the formation and decay of oxygen-modulated chemical-composition gratings in a standard telecommunication fiber are presented. Comparison between the decay experiment and the model provides a diffusion coefficient with an activation energy of 490 kJ/mol, which is in close agreement with reported values of oxygen self-diffusion in silica. The gratings have a diffusion-controlled decay behavior, with more than 50% of the reflectivity remaining after 7.5 h at a temperature of 1230 degrees C. The gratings show higher thermal stability when heated in air than in an inert argon atmosphere.
We demonstrate storage of polarization-entangled photons for 125 micros, a record storage time to date, in a 25-km-long fiber spool, using a telecommunications-band fiber-based source of entanglement. With this source we also demonstrate distribution of polarization entanglement over 50 km by separating the two photons of an entangled pair and transmitting them individually over separate 25-km fibers. The measured two-photon fringe visibilities were 82% in the storage experiment and 86% in the distribution experiment. Preservation of polarization entanglement over such long-distance transmission demonstrates the viability of all-fiber sources for use in quantum memories and quantum logic gates.