SEARCH · PubMed Health

Results for “Computer Storage Devices”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources

PubMed1993

[Computer-aided anesthesia monitoring. Experiences with the use of three systems in heart surgery].

Basic monitoring in cardiac anaesthesia embraces at least 19 different parameters of haemodynamics and blood gas analysis. In special cases additional measurements may be desirable, providing a total of up to 44 variables displayed on various monitors, as depicted in Fig. 2. The recording of such an amount of data is only feasible with automated recording systems. Therefore, in the past 6 years we have introduced three different computer systems to our cardiac anaesthesia workplaces. The experiences in their handling are reported. MATERIAL AND METHOD. Three systems were investigated: (1) System S 4000 (Siemens, Germany), based on a central processor unit (PDP 11, DEC, Japan) connected with 20 bedside input/output terminals and Sirecust 404a monitors (Siemens). The system collected the data in a ring buffer with a capacity for about 24-48 h. (2) Patient Care Manager (PCM; Siemens, Germany), a single workplace system based on an IBM-compatible personal computer (PC) with the operating system environment DOS 5.0/Windows 3.0. In our test configuration it was connected with a Sirecust 1281 monitor (Siemens). (3) Monitor-Data-Manager (MDM) (our own development). This single workplace system is also based on an IBM-compatible PC running under DOS and was connected to four different monitors used in our cardiac surgery operating theatre (Fig. 2). A second computer (Sirecust S 425, Siemens) served as an interface between the two 404 monitors (not featuring a serial output like RS 232) and the PC. The self-developed program for that interface was memory resistant and executable with three key presses when the anaesthetic record was started. The three systems were compared with regard to their ease of use, function and practicability. RESULTS. System S 4000: Because of the older system architecture, the response time to key inputs was fairly long and the menu structure somewhat uncomfortable. A major drawback was the limited data buffer capacity and the lack of a long-term storage medium as well as the lack of compatibility with the industry standard for PCs. Software interfaces to other companies' monitors were not implemented, limiting the system to the Sirecust 404 devices. Patient-Care-Manager: The user interface is a Windows 3.0 application representing an up-to-date graphical environment. Unfortunately some Windows features were not fully used, e.g. the free positioning and sizing of graphic windows and the color options. Drug inputs were somewhat long-winded, limiting the system's suitability for the operating theatre. The main disadvantage, however, was the lack of interfaces to monitors other than those from Siemens. Monitor Data Manager: The system was designed to sample data from all monitors operating in our hospital's heart surgery department. Each parameter was displayed in a digital form to get close control over the recorded data (Fig. 1b); additionally calculated values like total peripheral resistance or oxygen demand could be drawn from a separate window. Furthermore, key inputs were reduced to minimum, making drug inputs faster than the hand-written protocol. The ease of performing calculations of continuous drug infusions (from microgram/kg/min to ml/h pump speed) was particularly appreciated by the users. Since the data were saved as an ASCII file, they could easily be imported by any spreadsheet like Lotus 1-2-3 or Excel, providing the whole variety of their graphical presentation or calculation features. Because of the high sampling rate (3 min), even short-lasting drug effects could be registered, making the system favourable for scientific studies. CONCLUSION. Automated monitor data record systems are considered to be a prerequisite not only for research in anaesthesia but also for quality assurance. A basic requirement for wide acceptance in clinical practice is a user interface that provides fast and convenient key inputs as well as further information about parameters not displayed on other monitors. In our h

Anesthesia↗

PubMed2005

Personalized online information search and visualization.

BACKGROUND: The rapid growth of online publications such as the Medline and other sources raises the questions how to get the relevant information efficiently. It is important, for a bench scientist, e.g., to monitor related publications constantly. It is also important, for a clinician, e.g., to access the patient records anywhere and anytime. Although time-consuming, this kind of searching procedure is usually similar and simple. Likely, it involves a search engine and a visualization interface. Different words or combination reflects different research topics. The objective of this study is to automate this tedious procedure by recording those words/terms in a database and online sources, and use the information for an automated search and retrieval. The retrieved information will be available anytime and anywhere through a secure web server. RESULTS: We developed such a database that stored searching terms, journals and et al., and implement a piece of software for searching the medical subject heading-indexed sources such as the Medline and other online sources automatically. The returned information were stored locally, as is, on a server and visible through a Web-based interface. The search was performed daily or otherwise scheduled and the users logon to the website anytime without typing any words. The system has potentials to retrieve similarly from non-medical subject heading-indexed literature or a privileged information source such as a clinical information system. The issues such as security, presentation and visualization of the retrieved information were thus addressed. One of the presentation issues such as wireless access was also experimented. A user survey showed that the personalized online searches saved time and increased and relevancy. Handheld devices could also be used to access the stored information but less satisfactory. CONCLUSION: The Web-searching software or similar system has potential to be an efficient tool for both bench scientists and clinicians for their daily information needs.

Databases, Bibliographic↗

PubMed2001

The integrating ion imager: a device for determining heavy ion doses during irradiations.

We have designed and built an integrating ion imaging system (I3) that records the spatial distribution of the dose of heavy ions incident on samples irradiated at the radiobiology beamline of the Alternating Gradient Synchrotron at Brookhaven National Laboratory. The images of dose are integrated over the duration of the exposure. Unlike the images formed on X-ray film, these images are linear with the incident dose. Heavy ions are incident on a phosphor that is located just behind the sample position. Visible light emitted from the phosphor is collected by a lens and focused onto a scientific grade charge coupled device (CCD) cooled to about -45 degrees C. The phosphor and CCD camera are integral parts of a modular sample holder designed for irradiating molecular samples, which is easily mounted on the sample platform of the beamline. The imager can be adapted to other types of samples. The present CCD image is digitized to 14 bits (16,384 intensity levels), but the dynamic range is extended by adjusting the aperture of the CCD camera lens. Digital images from the CCD are routinely transferred over the BNL local area network for archival storage on a UNIX server, from which they can be opened from any authorized computer with access to the Internet. Images obtained with no sample in place record the dose at all points on the target field. When a sample is in place, an image of the sample appears providing its exact location with respect to fiducial marks recorded for all images. Areas surrounding the image of the sample are used in comparison with companion no-sample images to get exact doses over the sample. The contrast mechanism responsible for image formation is the shift along the Bragg curve resulting from loss of energy of the ions as they pass through the sample--not from a change in ion flux reaching the phosphor. The sharpness of the images formed with the DNA samples we have recorded indicates that neither scattering of the incident heavy ions or the generation of secondary ions contribute significantly.

Elementary Particles↗

PubMed1996

[A new approach of functional recto-anal exploration: the compliance of the rectum and the anal canal].

We have developed an original method of determining the rectal and the anal compliance. The rectum must serve as a fecal reservoir. This storage function requires that the rectum must be distensible. The anal canal must become easily looser for defecation. These features are not explored by the usual rectoanal manometric recordings. Very few investigations about the compliance are carried out. In our procedure, exploration balloons are connected via polyethylene tubes to pressure transducers, direct-writing electrical recorder and pump under the command of the computer. The pressure generated is as high as the distensibility is poor, as the compliance is decreased. The pressure/volume curve shows the compliance. The procedure is different for the rectum on the one hand, and for the anal canal on the other. The rectal device consists of a balloon at the end of the tube. It shall be inflated until only 60 ml., and then deflated at the same rythm, which is constant during each test. The first test takes place at the speed of 30 ml. per minute; so the inflation lasts 2 mn and the deflation the same time, afterwards the second test lasts one mn for each one, and finally the third one 40 seconds in the same way. For the anal canal, the balloon, ring shaped around the tube, measuring an inch in length, is inflated at only 12 ml. For the first test the inflation and deflation rate of speed is 3 ml per mn, afterwards 6 ml./mn then 9 ml./mn. and thereafter 12 ml./mn/; these series are done in randomized order. In both procedures, an additional relaxation test at the maximum of inflation takes place for 2 minutes. We have explored ten healthy volunteers and 120 patients suffering from various digestive diseases. The curves show the rectal compliance, and in the case of the anus a relaxation, which seems to be an active opening, occurs for a distension of 5-8 ml, i.e. 19-21 mn in diameter. In pathology, the excess of compliance is observed in patients with incontinence, whereas an inadequate compliance is seen in the dyschesia, descending perineum and prolapse, traumatic or surgical injuries, etc. This exploration will be a useful guide for the choice of the convenient treatment and the follow-up.

Adult↗

PubMed2007

Structure-property relationships in the optimization of polysilicon thin films for electrical recording/stimulation of single neurons.

We had earlier demonstrated the use of polysilicon microelectrodes for recording electrical activity from single neurons in vivo. Good machinability and compatibility with CMOS processing further make polysilicon an attractive interface material between biological environments on one hand and MEMS technology and digital circuits on the other hand. In this study, we focus on optimizing the polysilicon thin films for (a) electrical recording and (b) stimulation of single neurons by minimizing its electrochemical impedance spectra and maximizing its charge storage/injection capacity respectively. The structure-property relationships in ion-implanted (phosphorus) LPCVD polysilicon thin films under different annealing and doping conditions were carefully assessed during this optimization process. A 2D model of the polysilicon thin film consisting of 4 grains and 3 grain boundaries was constructed and the effect of grain size and grain boundaries on dc resistivity was simulated using device simulator ATLAS. Optimal processing conditions and doping concentrations resulted in a 10-fold decrease in electrochemical impedance from 1.1 kOmega to 0.1 kOmega at 1 kHz (area of polysilicon interface = 4.8 mm(2)). Subsequent characterizations showed that evolution of secondary grains within the polysilicon thin films at optimal doping and annealing conditions (10(21)/cm(3) of phosphorus and annealed at 1200 degrees C) was responsible for decreasing the impedance. Cyclic voltammetry studies demonstrated that charge storage properties of low doped (10(15)/cm(3)) thin films was 111.4 microC/cm(2) in phosphate buffered saline which compares well with platinum wires (approximately 50 microC/cm(2)) and the double-layered capacitance (C(dl)) could be sustained between -1 to 1 V before breakdown and hydrolysis. We conclude that polysilicon can be optimized for recording and stimulating single neurons and can be a valuable interface material between neurons and CMOS or MEMS devices.

Action Potentials↗

PubMed2002

[Development of the combined tumor therapeutic equipment].

This paper describes the development of the combined tumor therapeutic equipment based on the theory of 1 + 1 = 3 or 1 + 1 > 3 tumor combined treatment synergism. It has become a promising and valuable method dealing with cancer tumors for its good adaptability, better effectiveness and convenience. The therapeutic equipment is combined with PC and MS windows operation system, and adopts intellectual temperature control device, which realizes homogeneous and smooth heating to intracavity tumor focus and automatic processing and statistical management of all case data. The equipment works stably and is of great value in clinical applications.

Algorithms↗

PubMed2005

A concise method of calculating fetal weight percentile.

OBJECTIVE: Assessment of fetal growth used in clinical decision making for managing pregnancies is based on percentiles relative to normal values for gestational age. Most clinicians utilize visual interpolation of look-up tables or graphs, which is neither accurate nor convenient. Calculation of growth percentile by numerical integration formulas requires digital computers with advanced computational capabilities and/or the storage of large data tables. STUDY DESIGN: Using established ultrasound measurement formulas and published fetal weight/gestational age tables, mean weights and standard deviations for gestational ages from 10 to 44 weeks were determined. From this Z-scores were calculated for the gestational ages. Z-scores plotted against 1st through 50th percentiles resulted in a curve. A polynomial equation was derived to fit the curve resulting in an expression for converting the Z-score to percentile: Percentile = 0.0994 * Z score2 - 0.44 * Z score + 0.5026. RESULTS: Comparing calculated values from this equation against standard percentiles from a Z-score to percentile table, all calculated values varied from the table value by < 1 percentile for Z-scores ranging from 0 to 2.33. Values > 2.33 are assigned to the 99th percentile. The equation performed to the goal of calculating percentile to an accuracy of < or = 1 percentile. CONCLUSION: A method whereby the estimated fetal weight can be used to calculate a percentile using two simple equations and only standard math functions allows implementation on a standard personal digital assistant device commonly available for clinical use. This implementation gives the needed accuracy, ease of interpretation, and portability, making it a useful tool in clinical practice.

Fetal Weight↗

PubMed1993

The computer in the radiologist's office.

Today, the radiologist is able to equip his or her office with a powerful personal computer system equivalent to the large mainframe computers of just a few years ago. If funds permit, purchase of a 486 equivalent system with 200-300 Mbytes of hard-disk storage, 16 Mbytes of random access memory (RAM), a high-resolution color video card and monitor, and a laser printer is recommended. The practical uses for such a system are almost limitless and include word processing, spreadsheet and data-base management, telecommunications, multimedia presentations, business applications, teleradiology, resident and medical student education, and research applications. No matter how much one becomes involved in computer applications, it is essential to establish good habits for backing up critical data files and programs. Becoming familiar with computer technology is not easy at first. Finding a good computer buddy, taking simple night school courses, and reading computer articles and magazines are good ways to get started. Computers are wonderful devices. The day is fast approaching when they will become a necessary tool for every radiologist.

Microcomputers↗

PubMed2006

Specific interoperability problems of security infrastructure services.

Communication and co-operation in healthcare and welfare require a well-defined set of security services based on a standards-based interoperable security infrastructure and provided by a Trusted Third Party. Generally, the services describe status and relation of communicating principals, corresponding keys and attributes, and the access rights to both applications and data. Legal, social, behavioral and ethical requirements demand securely stored patient information and well-established access tools and tokens. Electronic signatures as means for securing integrity of messages and files, certified time stamps and time signatures are important for accessing and storing data in Electronic Health Record Systems. The key for all these services is a secure and reliable procedure for authentication (identification and verification). While mentioning technical problems (e.g. lifetime of the storage devices, migration of retrieval and presentation software), this paper aims at identifying harmonization and interoperability requirements of securing data items, files, messages, sets of archived items or documents, and life-long Electronic Health Records based on a secure certificate-based identification. It's commonly known that just relying on existing and emerging security standards does not necessarily guarantee interoperability of different security infrastructure approaches. So certificate separation can be a key to modern interoperable security infrastructure services.

Authorship↗

PubMed1977

[Image processing in pathology. III. Structure and use of an automatic morphometry system for recording morphometric features of nuclei (author's transl)].

UNLABELLED: An image processing system for morphological investigation of liver cell nuclei in biopsy specimens is demonstrated. The present study deals with the age dependence of normal hepatic nuclear areas. The results were compared with those of conventional methods. MATERIAL AND METHODS: The image processing system consists of a microscope, an image dissector and a computer (central processing unit, display, teletype, magnetic tape devices and line printer). 74 liver biopsies were investigated. They sshowed no signs of acute or chronic diseases. Paraffin sections of 4 micron in thickness were prepared and stained by Feulgen method. 8-10 biopsies were available for each decade from 1-8. 18,000 liver cell nuclei from all specimens were isolated and measured automatically. Using the image processing system and adequate computer programs 20 parameters of all isolated nuclei were gained (parameters of shape, size and structure of the nuclei). For sampling and processing of the information the following programs are developed: PROBE Program for investigation of optimal parameters of scanning and processing. SAMPL Program for scanning, object isolation, feature extraction and storage of data records. KORRL Program for investigation of correlations between the features of objects. LISTE Program for listing of data records. ULTRA Program for search of objects with extremal features. CODER Program for correction od data records. ADAPT Program for training of classificators. SCHAU Program for demonstration and checking of the classificator. MORPH Program for output of feature distributions and statistical parameters. Following object features were calculated and investigated: features of size: KOFL area within the object contour; KKFL minimal covex area of the object; ZKFL object area without holes; KONL length of the object contour.

Adolescent↗

PubMed2003

Two operative concepts for the post-genomic era: the "mémoire vive" of the cell and a molecular algebra.

The first successes in cloning experiments and stem cell "reprogramming" have already demonstrated the primordial role of cellular working-space memory and regulatory mechanisms, which use the knowledge stored in the DNA database in read mode. We present an analogy between living systems and informatics systems by considering: 1) the cell cytoplasm as a memory device accessible as read/write; 2) the mechanisms of regulation as a programming language defined by a grammar, a molecular algebra; 3) biological processes as volatile programs which are executed without being written; 4) DNA as a database in read only mode. We also present applications to two biological algorithms: the immune response and glycogen metabolism.

Biomimetics↗

PubMed2004

Indexing of multidimensional lookup tables in embedded systems.

The proliferation of color devices and the desire to have them accurately communicate color information has led to a need for embedded systems that perform color conversions. A common method for performing color space conversions is to characterize the device with a multidimensional lookup table (MLUT). To reduce cost, many of the embedded systems have limited computational abilities. This leads to a need for the design of efficient methods for performing MLUT indexing and interpolation. This paper examines and compares two methods of MLUT indexing within embedded systems. The comparison is made in terms of colorimetric accuracy and computational cost.

Algorithms↗

PubMed1994

Undersensing during ventricular tachyarrhythmias in a third-generation implantable cardioverter defibrillator: diagnosis using stored electrograms and correction with programming.

Third-generation implantable cardioverter defibrillators with stored electrograms allow diagnosis of various sensing problems that may lead to an inappropriate device response. Undersensing of ventricular tachyarrhythmias is a potentially serious problem, as it may lead to failure to deliver therapy. To determine the incidence of this problem, we reviewed 98 patients with Ventritex Cadence defibrillator systems and found 2 patients in whom defibrillation therapy was delayed or aborted because of undersensing during induced ventricular tachyarrhythmias. In both cases, examination of stored electrograms revealed variation in electrogram amplitude, which presumably resulted in failure of the autogain feature to increase its sensitivity enough to count each complex. During charging, criteria for redetection of sinus rhythm were met because of this undercounting, leading to failure to deliver defibrillation therapy. This problem was detected in both patients 4-6 weeks following device implant during device testing, and both patients had been started on antiarrhythmic drug therapy prior to this testing. Programming the sinus redetection parameter from nominal to slow, increasing the number of beats necessary to confirm resumption of sinus rhythm, corrected the problem in both patients. Device testing in the electrophysiology laboratory, routinely postoperatively and following initiation of antiarrhythmic drug therapy, and the ability to retrieve stored electrograms are useful in detecting such sensing anomalies.

Aged↗

PubMed2006

Metabolic flux analysis at ultra short time scale: isotopically non-stationary 13C labeling experiments.

A novel approach to (13)C metabolic flux analysis (MFA) is presented using cytosolic metabolite pool sizes and their (13)C labeling data from an isotopically non-stationary (13)C labeling experiment (INST-CLE). The procedure is demonstrated with an E. coli wild type strain grown at fed batch conditions. The intra cellular labeling dynamics are excited by a sudden step increase of the (13)C portion in the substrate feed. Due to unchanged saturation of the substrate uptake system, the metabolic fluxes remain constant during the following sampling time period of only 16s, in which 20 samples are taken by an automated rapid sampling device immediately stopping metabolism by methanol quenching. Subsequent cell disruptive sample preparation and LC-MS/MS enabled simultaneous determination of pool sizes and mass isotopomers of intra cellular metabolites requiring detection limits in the nM range. Based on this data the new computational flux analysis tool 13CFLUX/INST is used to determine the intra cellular fluxes based on a complex carbon labeling network model. The measured data is in good agreement with the model predictions, thus proving the applicability of the new isotopically non-stationary (13)C metabolic flux analysis (INST-(13)C-MFA) concept. Moreover, it is shown that significant new information with respect to flux identifiability, non-measurable pool sizes, data consistency, or large storage pools can be taken from the novel kind of experimental data. This offers new insight into the biological operation of the metabolic network in vivo.

Bioreactors↗

PubMed1969

Relevance of the electronic computer to hospital medical records.

During the past 30 years an "information explosion" has completely changed patterns of illness. Unit files of individual patients have become so large that they are increasingly difficult both to store physically and to assimilate mentally. We have reached a communications barriers which poses a major threat to the efficient practice of clinical medicine.At the same time a new kind of machine, the electronic digital computer, which was invented only 26 years ago, has already come to dominate large areas of military, scientific, commercial, and industrial activity. Its supremacy rests on its ability to perform any data procedure automatically and incredibly quickly.Computers are being employed in clinical medicine in hospitals for various purposes. They can act as arithmetic calculators, they can process and analyse output from recording devices, and they can make possible the automation of various machine systems.However, in the field of case records their role is much less well defined, for here the organization of data as a preliminary to computer input is the real stumbling-block. Data banks of retrospective selected clinical information have been in operation in some centres for a number of years. Attempts are now being made to design computerized "total information systems" to replace conventional paper records, and the possibility of automated diagnosis is being seriously discussed.In my view, however, the medical profession is in danger of being dazzled by optimistic claims about the usefulness of computers in case record processing. The solution to the present problems of record storage and handling is very simple, and does not involve computerization.

Computers↗

PubMed2005

Digital microfluidics using soft lithography.

Although microfluidic chips have demonstrated basic functionality for single applications, performing varied and complex experiments on a single device is still technically challenging. While many groups have implemented control software to drive the pumps, valves, and electrodes used to manipulate fluids in microfluidic devices, a new level of programmability is needed for end users to orchestrate their own unique experiments on a given device. This paper presents an approach for programmable and scalable control of discrete fluid samples in a polydimethylsiloxane (PDMS) microfluidic system using multiphase flows. An immiscible fluid phase is utilized to separate aqueous samples from one another, and a novel "microfluidic latch" is used to precisely align a sample after it has been transported a long distance through the flow channels. To demonstrate the scalability of the approach, this paper introduces a "general-purpose" microfluidic chip containing a rotary mixer and addressable storage cells. The system is general purpose in that all operations on the chip operate in terms of unit-sized aqueous samples; using the underlying mechanisms for sample transport and storage, additional sensors and actuators can be integrated in a scalable manner. A novel high-level software library allows users to specify experiments in terms of variables (i.e., fluids) and operations (i.e., mixes) without the need for detailed knowledge about the underlying device architecture. This research represents a first step to provide a programmable interface to the microfluidic realm, with the aim of enabling a new level of scalability and flexibility for lab-on-a-chip experiments.

Computers↗

PubMed1990

Enhancement and compression of digital chest radiographs.

The application of digital technologies to chest radiography holds the promise of routine application of image processing techniques to effect image enhancement. Because of their inherent spatial resolution, however, digital chest images impose severe constraints on data storage devices. Compression of these images will relax such constraints and facilitate image transmission on a digital network. We evaluated an algorithm for enhancing digital chest images that has allowed significant data compression while improving the diagnostic quality of the image. This algorithm is based on the photographic technique of unsharp masking. Image quality was measured with respect to the task of tumor detection and compression ratios as high as 2:1 were achieved. This compression can be supplemented by irreversible methods.

Algorithms↗

PubMed2001

Quantum computing in molecular magnets.

Shor and Grover demonstrated that a quantum computer can outperform any classical computer in factoring numbers and in searching a database by exploiting the parallelism of quantum mechanics. Whereas Shor's algorithm requires both superposition and entanglement of a many-particle system, the superposition of single-particle quantum states is sufficient for Grover's algorithm. Recently, the latter has been successfully implemented using Rydberg atoms. Here we propose an implementation of Grover's algorithm that uses molecular magnets, which are solid-state systems with a large spin; their spin eigenstates make them natural candidates for single-particle systems. We show theoretically that molecular magnets can be used to build dense and efficient memory devices based on the Grover algorithm. In particular, one single crystal can serve as a storage unit of a dynamic random access memory device. Fast electron spin resonance pulses can be used to decode and read out stored numbers of up to 105, with access times as short as 10-10 seconds. We show that our proposal should be feasible using the molecular magnets Fe8 and Mn12.

Journal Article↗