Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Local Area Networks”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 235 records · Page 13Linked to original sources

Three-dimensional presentation of cardiac morphology.

The results of a research project aiming to visualize cardiac anatomy in a 3-dimensional form for surgical planning are presented. Based on electronic data processing within a local area network environment, serial slices of CT- and MRI-machines were used to construct a 3-dimensional data cube that was illuminated by calculated sources of light. Light rays were traced through the entire "data volume". Mathematically following each pathway of light through the space, the intensity of changes along this path were calculated. The results of applying this "Heidelberg Ray-tracing Technique" to cardiac anatomy are 3-dimensional "computer movies" that appear on any workstation within a computer network. Using special software, the surgeon can "walk" in any direction through the heart or he can break it into two or more parts in order to analyze regions of interest in detail. Even small structures such as papillary muscles, bifurcations, coronary arteries and cusps of cardiac valves become visible. This new technique may enable the surgeon to open the heart prior to surgery on the computer monitor working with a visualized model that corresponds to the visual experience of his daily intraoperative practice.

Cardiac Surgical Procedures↗

[Digital internet-based ophthalmologic image databank].

OBJECTIVE: To manage an ophthalmological image database easily and rationally. MATERIALS AND METHODS: Fundus, macro and simultaneously recorded Fluorescein and ICG angiography images were digitized and archived using personal computers and UNIX workstations. Image data were written to CD-recordables. The CD-s with image information were stored in a jukebox-server. On demand image information was converted to dynamic hypertext markup language (html) with a WWW-server. Information stored on the servers could be observed with browser programs running on client computers connected to local area network. The communication with ophthalmologist working outside our hospital was realized by electronic mail. RESULTS: Different platforms (PC, Mac, workstations, etc.) and operating systems (Windows 3.x, 95, NT, MacOS, UNIX, etc.) can be used as clients. The communication with the system is accomplished by standard internet programs (Internet Explorer, Netscape Navigator, etc.). Thanks to the intuitive graphical user interface, no special computer knowledge is required to retrieve the stored data. CONCLUSION: Our digital image database has many advantages over a conventional image archive: it is round the clock available, images can be stored and copied without loss of quality, digital images can be easily integrated in other applications, it can be used without special computer knowledge, it is expandable and compatible with all contemporary computer platforms.

Computer Communication Networks↗

Feasibility of real-time echocardiographic evaluation during patient transport.

Echocardiography is a key diagnostic tool in evaluating patients with cardiac emergencies and chest trauma. The lack of qualified real-time interpretation limits its use by emergency first responders. Early diagnosis of cardiac emergencies has the potential to facilitate triage and medical intervention to improve outcomes. We investigated the feasibility of remote, real-time interpretation of echocardiograms during patient transport. Echocardiograms using a hand-carried ultrasound device were transmitted from an ambulance in transit to a tertiary care facility using a distributed mobile local area network. Transmitted studies were reviewed by a cardiologist for ability to interpret predefined features. Transmission quality and reliability were assessed. Echocardiographic images were successfully transmitted greater than 88% of transport time. The evaluation of left-ventricular size and function, and presence of pericardial effusion were greater than 90% concordant, but only 66% of all echocardiographic features were concordant. Most transmission losses were brief (<or=10 seconds) with little impact on interpretability. Wireless infrastructures in metropolitan areas provide the ability for real-time transmission of echocardiograms during patient transport of adequate quality for accurate interpretation.

Ambulances↗

Web pages: an effective method of providing CAI resource material in histology.

Increased student numbers and the recognition that computer skills are essential for medical students led to the introduction of computer-aided instruction (CAI) resource material as an integral part of the second-year histology course at the University of Natal (South Africa) Medical School. Several copies of a commercial software package (compact disc-CD) covering the entire course were available. During the course of the year, using the physical and human resources available, the first in-house software package ('The Integumentary System') was generated in MS Word and saved as a series of linked html documents. The package could be accessed simultaneously by all students via the local area network (LAN). As part of an extensive evaluation of the introduction of CAI in histology, student comments and criticisms of the commercial and in-house package were canvassed. The response regarding the in-house software was encouraging, with students perceiving that it met their educational needs, preferring it to the commercial package. This report describes the ease with which this software can be developed, using limited resources and available skills, while providing students with valuable learning opportunities.

Journal Article↗

Telecardiology for effective healthcare services.

Continuous monitoring of the electrocardiogram (ECG) and other signals related to current heart activity are necessary for patients who are suffering from cardiac diseases. This paper deals with the work that has been carried out to transmit ECGs from remote sites. Software has been developed which enables the uploading of ECG data from a patient so that the physician can monitor the state of the patient from a distance and at the same time may consult other experts for a second opinion. Records can only be examined by the authorized physician after proper registration and diagnosis or prescription may be sent back to the referring site. Further consultation with the patient through a 'chat' facility is also possible. The suitability of the system over transport control protocol (TCP), internet protocol (IP), local area network (LAN), wide area network (WAN) and World Wide Web (WWW) has been assessed. The bandwidth, latency, availability, security and ubiquity have also been discussed. A study has also been undertaken in order to make the system compatible with available bandwidths and to find out which one out of a number of available techniques is most efficient for ECG data compression. The results indicate that the scheme is suitable for telecardiology and can form part of an overall telemedicine system in a health care network.

Computer Security↗

"Robo-Rad": an inexpensive user-friendly multimedia report system for radiology.

BACKGROUND AND PURPOSE: The complex information obtained by CT, MR, and ultrasound examinations is often difficult to convey with a written report. Today's multimedia computer technology provides a medium within which the audio and the visual components of a radiologic consultation can be made available simultaneously, with the projected capability of remote access from any personal computer. A system was developed to run on low-end computer systems with image quality adequate for reporting purposes and prudent memory management (each report occupies < 4 MB). With this system-"Robo-Rad"-the image and radiologist are recorded simultaneously while he or she describes and points out (with a mouse) areas of interest. This dynamic report, along with patient data, can be retrieved and viewed by the consulting physician at his/her convenience using a low-end PC or Macintosh computer. MATERIALS AND METHODS: To assess the clinical utility of Robo-Rad, survey responses were solicited from clinical physicians at the Penn State University Hospital (41.5% faculty/fellows, 31.7% residents, 11.8% medical students, 2% clinical nursing; n = 101) during a hands-on demonstration using studies of 35 consecutive inpatients whose CT scans had been dictated into the system. RESULTS: In an average week, the surveyed professionals ordered 3.2 +/- 3.0 CT studies, reviewed 3.8 +/- 3.0 CTs, spent 1.5 +/- 2.0 hours locating Ct studies, and discussed 2.3 +/- 1.9 CT cases with a radiologist. The average time spent discussing a single CT case with a radiologist was reported as 9.4 +/- 5.9 minutes. On a five-point rating scale (1 = not at all to 5 = very much so), respondents indicated that the Robo-Rad report was helpful (4.3 +/- 0.7) and provided clinically important information that would be difficult to convey with current dictation systems (4.2 +/- 0.8). Desire to discuss the case with a radiologist in addition to viewing the Robo-Rad report scored 3.2 +/- 1.0. If such a system were readily available, 91.8% of the respondents indicated that they would use it in addition to the currently available written report and audio dictation system, and 96.6% would use it instead of the current system. Local area network and modems were the modalities of highest interest for remote access (69.3% and 44.6%, respectively). CONCLUSIONS: Judging by these data, the Robo-Rad system would be of benefit to clinicians. It provides a user-friendly, low-cost multimedia radiology report utilizing readily available technology to improve radiologist-clinician communication.

Attitude of Health Personnel↗

Wireless technologies and patient safety in hospitals.

In the development of policies for wireless technologies, it is important for healthcare organizations to reduce risks to patients from use of wireless devices. Policy should be devised for instructing hospital staff, visitors, and patients, avoiding unwarranted restrictions but not ignoring evidence regarding potential interference problems, and allowing comparison with other clinical facilities of benefits of policy. To inform policy developers and a general audience of hospital personnel, a review was conducted on the safety of wireless devices for communication within hospitals. This review targeted electromagnetic interference effects of devices on medical devices and summarises key recommendations from published reports and international standards. There is consensus that the highest risk of interference occurs with two-way radios used by emergency crews, followed by mobile phones, while radio local area networks produce negligible interference. Wireless technologies are deemed suitable for use throughout hospital areas including intensive care units and operating rooms, given that recommended separation distances from medical equipment are observed.

Cell Phone↗

Diagnostic imaging pathways: development, dissemination, implementation, and evaluation.

ISSUE: There are signs of inappropriate application of medical imaging to diagnosis. Inappropriate imaging is a threat to effective diagnosis and effective allocation of resources. The development and deployment of knowledge-based clinical decision support systems is one strategy to reduce inappropriate imaging. DEVELOPMENT OF IMAGING PATHWAYS: A suite of 78 imaging pathways was conceived both as a decision support and educational tool. The pathways were drafted by imaging specialists, but further developed and modified, based on graded evidence and input from requesting clinicians. An electronic environment was developed to contain and deliver the pathways. DISSEMINATION AND IMPLEMENTATION: Imaging pathways were distributed via a hospital local area network and on compact disk. A multifaceted approach was used to raise general awareness of the pathways, followed by intensive 'marketing' activities. Two groups of clinicians were targeted; hospital-based clinicians and general practitioners. EVALUATION: There was increased awareness of imaging pathways. Clinicians judged them to be useful for education and decision support. The method of electronic delivery was adequate. Knowledge of diagnostic imaging and requesting behaviour tended to become more aligned with the pathways. The central objective to reduce inappropriate medical imaging seems to be achievable. LESSONS LEARNED: There is scope to improve the content and the electronic environment, achieve better integration into decision-making processes, and achieve better compliance. A linkage between imaging pathways and electronic requesting could provide alerts to 'non-compliant' requesting. The assignment of a higher cost, or a lower remuneration, to non-authorized and non-compliant imaging would provide tangible incentive to comply, unless there are compelling clinical contraindications.

Attitude of Health Personnel↗

Cornerstone: Illinois' approach to service integration.

Cornerstone is a management information system developed and implemented by the Illinois Department of Public Health as a mechanism to facilitate maternal and child health service integration. Its design features combined program registration, standardized risk assessment, automated care plan development, and consolidated referral and scheduling. Cornerstone is a flexible, PC- and local area network-based system, allowing portability across program applications and geographic areas. A wide-area network enables local agencies to share data about clients. Development of Cornerstone was a collaborative effort by potential Cornerstone users and statewide administrative staff. The standard for equipment is set at a one-to-one ratio of workstations to case managers.

Computer Systems↗

Regional emergency preparedness efforts by local health departments in Western New York.

Public health agencies at all levels are now under increasing pressure to prepare for and respond to emerging natural and manmade threats to the health and wellness of those they serve. In particular, local health departments must be prepared to provide front-line defense and first response as threats of terrorism have become increasingly real. Success in meeting this monumental task will be highly dependent on funding as well as the availability of other resources. Although local health departments serving smaller counties may have fewer resources and receive less preparedness funding, they must still develop similar plans, surveillance systems, and response capabilities as local health departments serving larger counties (albeit on a smaller scale). Although local health departments serving larger counties may have more resources and receive more preparedness funding, they may face a greater chance of an intentional terrorist act and could benefit from support from local health departments serving smaller counties. Regional planning and response solutions to this challenge will allow partnerships of small and large local health departments to pool their resources and cooperatively provide more services with less duplication using whatever funding is available. This article describes that process as it is occurring in western New York among eight local county health departments.

Bioterrorism↗

A telemetry system for the study of spontaneous cardiac arrhythmias.

The characteristics of spontaneous cardiac arrhythmias leading to sudden cardiac death are largely unknown. To study arrhythmias in animal models, an eight-channel implantable radio telemetry system has been developed to record continuously cardiac electrograms over a period of weeks to months, with maintenance restricted to changing batteries. The inputs are connected in a unipolar manner. Each channel has a gain of fifty and is AC coupled, band limited to 0.07-260 Hz. The signals are digitized with 12 bits resolution at 1000 samples/s. The amplifiers, analog-to-digital converter, and control logic are packaged in an implantable unit. An umbilical cable is passed through the skin to an external backpack unit for power and data transmission. A custom serial interface card, a PC/104 form factor 25-MHz 80386-based single-board computer with a PCMCIA wireless local area network (WLAN) card, and battery power supply make up the backpack. Data are read into the parallel port of the computer, buffered, then transmitted over the WLAN to the laboratory network where it can be analyzed and archived. Approximately 12 h of 14,000 bytes/s data can be collected with each set of batteries. The system is suitable for continuous monitoring of animal models of spontaneous arrhythmias and sudden cardiac death.

Animals↗

Effects of layer thickness for SAW, PSAW, and HVPSAW devices.

Considerable efforts in recent SAW device design and development have been aimed at obtaining high frequency, low loss, and high performance. A large number of applications relate to cellular and mobile telephony, pagers, local area networks, cordless phones, global positioning systems (GPS), and security systems. Pseudo-SAW (PSAW) and high velocity PSAW (HVPSAW) have received great attention because of their high phase velocities and, therefore, the high frequencies of operation that these modes provide. In addition to high phase velocities, the pseudomodes must also present low propagation losses and considerably high electromechanical coupling coefficients to be considered for surface acoustic wave (SAW) devices. This paper verifies that the metallic layer thickness is a relevant SAW device parameter, which must be considered to achieve lower losses for high frequency, low loss SAW devices. Popular PSAW and HVPSAW material orientations, such as 64 degrees YX LiNbO3 (0 degree -26 degrees 0 degree), 36 degrees YX LiTaO3 (0 degree -54 degrees 0 degree), LiNbO3 (90 degrees 90 degrees 36 degrees), LiTaO3 (90 degrees 90 degrees 31 degrees), and Li2B4O7 (0 degree 47.3 degrees 90 degrees), are considered as examples. In addition to the reduced loss analysis and the dispersion analysis for the pseudo modes, the present work discusses the transitions with respect to the layer thickness from the PSAWs and HVPSAWs to the generalized SAWs (GSAWs) and Rayleigh (sagittal particle motion) modes. In addition to contributing to the knowledge of the pseudomodes behavior with layer thickness, this mode transition analysis enlightens the situation in which the losses in the pseudo modes go to zero because of the merging of the pseudo modes into the SAWs (GSAWs and Rayleigh). The fact that the SAWs are a continuation as a function of thickness for the pseudo modes may be conveniently used in the fabrication of low loss devices. In addition, the effects of heavy layer metals, such as gold, in reducing the layer thickness at which the pseudo modes merge to the SAWs are discussed. Numerical results are compared with experimental data available in the literature, and the present analysis elucidates experimentally observed higher order pseudo modes and values of layer thickness for which lower losses are achieved.

Journal Article↗

A wireless PDA-based physiological monitoring system for patient transport.

This paper proposes a mobile patient monitoring system, which integrates current personal digital assistant (PDA) technology and wireless local area network (WLAN) technology. At the patient's location, a wireless PDA-based monitor is used to acquire continuously the patient's vital signs, including heart rate, three-lead electrocardiography, and SpO2. Through the WLAN, the patient's biosignals can be transmitted in real-time to a remote central management unit, and authorized medical staffs can access the data and the case history of the patient, either by the central management unit or the wireless devices. A prototype of this system has been developed and implemented. The system has been evaluated by technical verification, clinical test, and user survey. The evaluation of performance yields a high degree of satisfaction (mean = 4.64, standard deviation--SD = 0.53 in a five-point Likert scale) of users who used the PDA-based system for intrahospital transport. The results also show that the wireless PDA model is superior to the currently used monitors both in mobility and in usability, and is, therefore, better suited to patient transport.

Adult↗

On the performance of telemedicine system using 17-GHz orthogonally polarized microwave links under the influence of heavy rainfall.

This paper describes the design of a telemedicine system based on next-generation wireless local area networks (WLANs) operating at 17 GHz. Seventeen gigahertz is proposed for next-generation WLAN services offering numerous advantages over traditional IEEE 802.11 networks that operate in the range of 2.4-5 GHz. Orthogonal polarization is often used to increase spectrum efficiency by utilizing signal paths of horizontal and vertical polarization. Radio waves exceeding 10 GHz are particularly vulnerable to signal degradation under the influence of rain which causes an effective reduction in isolation between polarized signal paths. This paper investigates the influence of heavy rain in a tropical region on wide-band microwave signals at 17 GHz using two links provided by a fixed broad-band wireless access system for two-way data exchange between paramedics attending an accident scene and the hospital via microwave equipment installed in the ambulance. We also study the effects of cross polarization and phase rotation due to persistent heavy rainfall in tropical regions.

Computer Communication Networks↗

RTWPMS: a real-time wireless physiological monitoring system.

This paper demonstrates the design and implementation of a real-time wireless physiological monitoring system for nursing centers, whose function is to monitor online the physiological status of aged patients via wireless communication channel and wired local area network. The collected data, such as body temperature, blood pressure, and heart rate, can then be stored in the computer of a network management center to facilitate the medical staff in a nursing center to monitor in real time or analyze in batch mode the physiological changes of the patients under observation. Our proposed system is bidirectional, has low power consumption, is cost effective, is modular designed, has the capability of operating independently, and can be used to improve the service quality and reduce the workload of the staff in a nursing center.

Computer Systems↗

Analysis of a master-slave architecture for distributed evolutionary computations.

This paper introduces a new mathematical model of the master-slave architecture for distributed evolutionary computations (EC). This model is validated using a concrete implementation based on the Distributed BEAGLE C++ framework. Results show that contrary to (current) popular belief, master-slave architectures are able to scale well over local area networks of workstations using off-the-shelf networking equipment. The main properties of the master-slave are also compared with those of the more mainstream island-model.

Artificial Intelligence↗

A national survey to assess current use of computerised information systems in obstetrics.

OBJECTIVE: To ascertain the number and type of obstetric computer systems (OCS) in Great Britain, and to ascertain user satisfaction with these systems. DESIGN: A postal questionnaire was circulated to every consultant obstetrician in Great Britain at the beginning of 1992. MAIN OUTCOME MEASURES: Information was sought on the hardware, software and uses of obstetric computer systems. Satisfaction with, benefits and problems of the system were also assessed. RESULTS: There was an 87.5% response rate. Of the 264 units questioned, 100 units reported that they had a computer system. Sixty-five units used terminals connected to a mainframe or minicomputer and 17 used stand-alone personal computers (PCs). Local area networks (LANs) were used in 19 units and wide area network (WANs) in 22 units. Software varied from commercial turnkey systems to in-house systems. The quoted annual running cost ranged from 50 pounds to 48,000 pounds. Most units were satisfied with their system. Problems included slow operating times, unreliability, user unfriendliness, deficiencies in training and inadequate customer support services. CONCLUSIONS: Obstetric computer systems are now coming into widespread use. Despite problems, the use of such systems is likely to increase. This survey establishes a database for those units who are considering acquiring or changing their computer system for the purpose of audit or research.

Attitude to Computers↗

On the use of C-arm fluoroscopy for treatment planning in high dose rate brachytherapy.

Treatment planning for brachytherapy requires the acquisition of geometrical information of the implant applicator and the patient anatomy. This is typically done using a simulator or a computed tomography scanner. In this study, we present a different method by which orthogonal images from a C-arm fluoroscopic machine is used for high dose rate brachytherapy treatment planning. A typical C-arm is not isocentric, and it does not have the mechanical accuracy of a simulator. One solution is to place a reconstruction box with fiducial markers around the patient. However, with the limited clearance of the C-arm this method is very cumbersome to use, and is not suitable for all patients and implant sites. A different approach is adopted in our study. First, the C-arm movements are limited to three directions only between the two orthogonal images: the C-orbital rotation, the vertical column, and the horizontal arm directions. The amounts of the two linear movements and the geometric parameters of the C-arm orbit are used to calculate the location of the crossing point of the two beams and thus the magnification factors of the two images. Second, the fluoroscopic images from the C-arm workstation are transferred in DICOM format to the planning computer through a local area network. Distortions in the fluoroscopic images, with its major component the "pincushion" effect, are numerically removed using a software program developed in house, which employs a seven-parameter polynomial filter. The overall reconstruction accuracy using this method is found to be 2 mm. This filmless process reduces the overall time needed for treatment planning, and greatly improves the workflow for high dose rate brachytherapy procedures. Since its commissioning nearly three years ago, this system has been used extensively at our institution for endobronchial, intracavitary, and interstitial brachytherapy planning with satisfactory results.

Artifacts↗