Storage of digital images.
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Optical disc technology can be either analog or digital. Analog (videodiscs) simulation programs are available for the allied health professions educator to incorporate into the curriculum. Digital optical discs, currently available in three formats, follow standards that have been adopted by the International Standards Organization. The formats differ in the amount of information they can accommodate and their practical use in the health professions curriculum.
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Photographic images make an important contribution to medical education. Conventional means of display have included 35-mm projection, film, videotape, and more recently, analog videodiscs that accompany computer-based text. The availability of compact discs, with their enormous storage capacity, and of powerful central processing units now permits consideration of digital storage of visual images for display by the personal computer. The data processing required for the representation and transfer of high-quality images is forbidding, however, even with today's technology. The problem is compounded if one anticipates display of full-motion video. In this tutorial we first review the nature of analog signals and the process of capturing them in digital format. We then consider mass storage and the concept of compressing data into smaller amounts of information that can be processed and transferred by personal computers with the use of optical disc drives. A look into the future provides a vision of high-definition television-quality video in digital format.
This paper describes a project to develop and test a new telemedicine system using image transmission. The system was implemented at Aomori prefecture, the northernmost prefecture of Japan, to provide medical consultation to remote hospitals from a medical center located in Aomori city, capital of the prefecture. The characteristics of the system are the combination of an HDTV still image transmission system and an ordinary tele-conference system using 65 kilobit telephone line i.e., an ordinary telephone line available in almost any part of Japan. We also developed a disk storage system that stores transmitted images automatically without human intervention. The system was assessed in real clinical settings and has proved to be effective in various areas of medical consultation, including radiology, pathology, dermatology, etc. We hope that this system becomes a standard telemedicine system in the future.
A system developed for long-term simultaneous recording of oesophageal motility and pH in the ambulant patient is described. The system consists of a microprocessor based data-acquisition and preprocessing device, a personal computer for postprocessing, report generation and data storage, a miniature two-sensor pressure catheter and a pH electrode. Identification and classification of oesophageal contractions are performed in separate steps, using online preprocessing software for identification and offline postprocessing software for categorisation, classification and report generation. Contractions are categorised as peristaltic, simultaneous or nontransmitte and classified according to their amplitude, duration and propagation velocity. The method described reduces the amount of data from 870 kbyte to approximately 40 kbyte per 24 hours in a multiparameter recording device, and offers the opportunity for offline postprocessing with different sets of criteria. The system has been found to be accurate and reliable in 24-hour studies in both healthy volunteers and patients with non-cardiac chest pain.
Different imaging techniques are used to pick up the signal of interest in digital sensors, including charge-coupled devices (CCD), complementary metal-oxide semiconductors (CMOS), photostimulable phosphors plates (PSP) and tuned-aperture computed tomography (TACT) Digital radiography sensors are divided into: storage phosphor plates (SPP) called photostimulable phosphor plates (PSP), silicon devices such as charge-coupled devices (CCD) or complementary metal oxide semiconductors (CMOS). Relatively new type of imaging that may hold advantage over current radiographic modalities is tuned-aperture computed tomography (TACT).
Until today, most of the documentation of forensic relevant medical findings is limited to traditional 2D photography, 2D conventional radiographs, sketches and verbal description. There are still some limitations of the classic documentation in forensic science especially if a 3D documentation is necessary. The goal of this paper is to demonstrate new 3D real data based geo-metric technology approaches. This paper present approaches to a 3D geo-metric documentation of injuries on the body surface and internal injuries in the living and deceased cases. Using modern imaging methods such as photogrammetry, optical surface and radiological CT/MRI scanning in combination it could be demonstrated that a real, full 3D data based individual documentation of the body surface and internal structures is possible in a non-invasive and non-destructive manner. Using the data merging/fusing and animation possibilities, it is possible to answer reconstructive questions of the dynamic development of patterned injuries (morphologic imprints) and to evaluate the possibility, that they are matchable or linkable to suspected injury-causing instruments. For the first time, to our knowledge, the method of optical and radiological 3D scanning was used to document the forensic relevant injuries of human body in combination with vehicle damages. By this complementary documentation approach, individual forensic real data based analysis and animation were possible linking body injuries to vehicle deformations or damages. These data allow conclusions to be drawn for automobile accident research, optimization of vehicle safety (pedestrian and passenger) and for further development of crash dummies. Real 3D data based documentation opens a new horizon for scientific reconstruction and animation by bringing added value and a real quality improvement in forensic science.
For data acquisition intensive care neurosurgery increasingly has recourse to modern electronics, which have become an integral part of many aspects of present-day neurosurgery. Despite their high technical standard, the devices in common use often lack flexibility. Their range of possible applications is defined by the manufacturer, and the user has little or no influence on them. Moreover, there are often no adequate interfaces to peripherals, and the storage capacity is limited. We would like to present a data acquisition system on a PC/AT basis, which operates up to 64 channels allowing parallel registration, storage, analysis, and of decisive importance, also various computations, i.e. correlation. Computation is rarely feasible on commercial devices, but it is essential for specific demands, such as implementation of PA/PM diagrams to determine intracranial compliance. In addition, the pertinent software permits implementation of Fourier analyses, offers separate statistical functions, and transfers data to other programs. The program is capable of automatic batch-processing, which greatly facilitates its use.
A method for the integration of a picture archiving and communication system (PACS) at Kyushu University Dental Hospital with radiological information (RIS) and hospital information (HIS) systems is described. CT, US and DSA from different manufacturers were integrated by videocapture and then subsequently integrated with computed radiography (CR) by means of DICOM. The approximate amount of data stored each month on optical discs is 2 GB. The system does not incorporate intra-oral radiography.
Digital images generated by medical imaging form the basis for radiological diagnosis and surgical planning. Despite the advent of the DICOM 3.0 standard for medical image communication, widespread application of the existing information is often limited by incompatibility of the data formatting used by different equipment generations, and the manufacturer-specific standards employed. An exchange interface based on magneto optical discs has been developed to retrieve and present medical image data regardless of the technological hardware and the specific formats used. Specially adapted routines to retrieve the data first had to be developed. A modular program structure was used to allow flexibility in the implementation of further routines and other exchange media. Over 20,000 CT and MRI images including header information obtained from different General Electric and Siemens scanners were extracted successfully from MO discs. The image data were used for follow up and surgical planning and were transferred to a PAC-server. The interface proved reliable and easy to use. Support for further proprietary formats is currently being developed. The present exchange interface permits reliable retrieval of digital images for diagnostic and surgical planning purposes, regardless of the hardware generation and manufacturer-specific formats.
Several recent technological advances have considerably improved the field of confocal fluorescence microscopy. Improvements in confocal microscope design, new fluorescent probes and indicators, more sensitive imaging devices, and computer advances which allow for data manipulation and storage provide a convenient method to acquire complex three-dimensional (3-D) architectural details which previously were difficult or impossible to obtain from biological specimens. Applications of the laser scanning and tandem scanning confocal microscopes offer the potential for gaining powerful insights into the complex relationship of cellular structure and function. Confocal microscopy generates optical sections free from out-of-focus blur. With the development of new visualization tools to render and display complex 3-D data, a set of optical sections taken at different focal planes can be three-dimensionally reconstructed to create an animated sequence which can reveal latent features of the specimen. The combination of confocal microscopy and 3-D reconstruction provides a powerful new imaging tool to advance knowledge about structural and functional cellular properties as they occur dynamically in three dimensions.
Isolated cardiac muscle cells enzymatically digested with collagenase and hyaluronidase from whole rat myocardium demonstrate the characteristics of an intact membrane in that they tolerate millimolar concentrations of free Ca2+ and exhibit phasic contractions with electrical excitation. These isolated cells maintain their characteristic A-I band striation patterns when at rest or during contraction. An apparatus has been developed to directly image these cells with phase-contrast micrography onto a 1,728-element charge-coupled device photodiode array for rapid data storage in a digital computer. The digitized striation pattern profile was analyzed for individual and average sarcomere spacing. In isotonic media the average resting sarcomere length ranged from 1.77 to 1.91 micrometers in 13 cells, with a mean length of 1.83 +/- 0.12 micrometers. Electrically stimulated phasic contractions in three cells demonstrated a synchronous 20% decrease in sarcomere spacing to a mean of 1.51 micrometers. Striation spacing decreased under hypertonic stress but elongated only up to 1.93 micrometers in hypotonic solutions, suggesting that some internal elastic constraint exists that limits elongation of the cell.
LiCoO2 is the most common lithium storage material for lithium rechargeable batteries, used widely to power portable electronic devices such as laptop computers. Operation of lithium rechargeable batteries is dependent on reversible lithium insertion and extraction processes into and from the host materials of lithium storage. Ordering of lithium and vacancies has a profound effect on the physical properties of the host materials and the electrochemical performance of lithium batteries. However, probing lithium ions has been difficult when using traditional X-ray and neutron powder diffraction techniques due to lithium's relatively low scattering power when compared with those of oxygen and transition metals. In the work presented here, we have succeeded in simultaneously resolving columns of cobalt, oxygen and lithium atoms in layered LiCoO2 battery material, using experimental focal series of LiCoO2 images obtained at sub-ångstrom resolution in a mid-voltage transmission electron microscope. Lithium atoms are the smallest and lightest metal atoms, and scatter electrons only very weakly. We believe our observations of lithium to be the first by electron microscopy, and that they show promise for direct visualization of the ordering of lithium and vacancies in transition metal oxides.
OBJECTIVE: In this article, we describe the implementation of a digital archive center for a radiology department in a 700-bed teaching hospital. MATERIALS AND METHODS: The archive center consists of two identical archive systems, each comprising five components: an archive server, a data-base server, an optical disk library, a stand-alone optical disk drive, and a communication network. An image management system controls the image traffic from acquisition devices to display stations. A fault-tolerant mechanism was built into the archive center to achieve a 100% uptime. RESULTS: The center has been in operation for over 6 months. We have not experienced a single total system failure during this period. It currently archives all digital images from three MR units and four CT scanners and selected images from three computed radiographic systems and two laser film digitizers. The center archives between 1.5 and 2.0 gigabytes of images per workday. CONCLUSION: With its built-in fault-tolerant mechanism, we believe that the implemented archive center is very reliable and is suitable for a radiology department to archive its digital images.
BACKGROUND: The validation of self-measurement devices for clinical use by elderly patients has been recommended. The Omron HEM-722C device has recently been validated according to the British Hypertension Society (BHS) protocol for use for general populations and the Omron HEM-735C is a new fully automatic device with a high capacity for storage of measurements that is integrated with a personal computer. OBJECTIVE: To perform a clinical validation for use by elderly people of the Omron HEM-722C and HEM-735C devices according to the revised protocol of the BHS and the criteria of the Association for the Advancement of Medical Instrumentation (AAMI). METHODS: We carried out a main validation test according to the revised BHS protocol for validation procedures for special groups on two groups of 30 subjects aged more than 65 years (29 men and 31 women), 11 of 30 with systolic blood pressures (SBP) <110mmHg, 10 of 30 with SBP >200 mmHg, 15 of 30 with diastolic blood pressures (DBP( <70 mmHg and 10 of 30 with DBP >110 mmHg. The results were graded according to the BHS system from A to D. RESULTS: The Omron HEM 722C achieved an overall A/A grading and satisfied the AAMI criteria for accuracy whereas the Omron HEM-735C achieved an overall B/A grading and satisfied the AAMI criteria for accuracy. The sphygmomanometer measurements were 147 +/- 31/79 +/- 15 and 144 +/- 30/78 +/- 15 mmHg (means+/-SD) respectively, for the models 722C and 735C. The average differences between mercury sphygmomanometer and HEM-722C readings for SBP and DBP were, respectively, 0.76+/-5 and 0.41+/-8 mmHg; those for HEM-735C were, respectively, 0.24+/-8 and 0.9+/-8 mmHg. Readings of the HEM-722C device differed by less than 5 mmHg for 76% of systolic readings and 96% of the readings differed by less than 10 mmHg. Diastolic measurements differed by less than 5 mmHg for 71% and less than 10 mmHg for 71 and 87% of all readings. Readings of the HEM-735C device differed by less than 5 mmHg for 68% of systolic readings and 74% of the readings differed by less than 10 mmHg. Diastolic measurements differed by less than 5 mmHg in 74% and less than 10 mmHg in 88 and 87% of all readings. CONCLUSIONS: On the basis of these results, for elderly subjects both self-measurement devices (Omron HEM-722C and HEM-735C) satisfied the validation criteria of the BHS and therefore can be recommended for the clinical measurement of blood pressure in elderly patients.
Many dynamical stochastic processes occur "on top" of a deterministic process. We present a method which uses the trajectory of the deterministic process as basis functions for quasiarbitrary distributions. A map for the stochastic process can then be computed. This may have applications in electron storage rings or other devices perturbed by a small stochasticity. In this paper we will look only at the most elementary applications of the method.
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