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PubMed1994

New IEEE standard enables data collection for medical applications.

The IEEE has gone to ballot on a "Standard for Medical Device Communications", IEEE P1073. The lower layer, hardware portions of the standard are expected to be approved by the IEEE Standards Board at their December 11-13, 1994 meeting. Other portions of the standard are in the initial stages of the IEEE ballot process. The intent of the standard is to allow hospitals and other users to interface medical electronic devices to host computer systems in a standard, interchangeable manner. The standard is optimized for acute care environments such as ICU's, operating rooms, and emergency rooms. [1] IEEE General Committee and Subcommittee work has been on-going since 1984. Significant amounts of work have been done to discover and meet the needs of the patient care setting. Surveys performed in 1989 identified the following four key user requirements for medical device communications: 1) Frequent reconfiguration of the network. 2) Allow "plug and play" operation by users. 3) Associate devices with a specific bed and patient. 4) Support a wide range of hospital computer system topologies. Additionally, the most critical difference in the acute care setting is patient safety, which has an overall effect on the standard. The standard that went to ballot meets these requirements. The standard is based on existing ISO standards. P1073 is compliant with the OSI seven layer model. P1073 specifies the entire communication stack, from object-oriented software to hospital unique connectors. The standard will be able to be put forward as a true international standard, much in the way that the IEEE 802.x family of standards (like Ethernet) were presented as draft ISO standards.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Communication Networks↗

PubMed2004

AMON: a wearable multiparameter medical monitoring and alert system.

This paper describes an advanced care and alert portable telemedical monitor (AMON), a wearable medical monitoring and alert system targeting high-risk cardiac/respiratory patients. The system includes continuous collection and evaluation of multiple vital signs, intelligent multiparameter medical emergency detection, and a cellular connection to a medical center. By integrating the whole system in an unobtrusive, wrist-worn enclosure and applying aggressive low-power design techniques, continuous long-term monitoring can be performed without interfering with the patients' everyday activities and without restricting their mobility. In the first two and a half years of this EU IST sponsored project, the AMON consortium has designed, implemented, and tested the described wrist-worn device, a communication link, and a comprehensive medical center software package. The performance of the system has been validated by a medical study with a set of 33 subjects. The paper describes the main concepts behind the AMON system and presents details of the individual subsystems and solutions as well as the results of the medical validation.

Activities of Daily Living↗

PubMed2005

Autonomous stair-climbing with miniature jumping robots.

The problem of vision-guided control of miniature mobile robots is investigated. Untethered mobile robots with small physical dimensions of around 10 cm or less do not permit powerful onboard computers because of size and power constraints. These challenges have, in the past, reduced the functionality of such devices to that of a complex remote control vehicle with fancy sensors. With the help of a computationally more powerful entity such as a larger companion robot, the control loop can be closed. Using the miniature robot's video transmission or that of an observer to localize it in the world, control commands can be computed and relayed to the inept robot. The result is a system that exhibits autonomous capabilities. The framework presented here solves the problem of climbing stairs with the miniature Scout robot. The robot's unique locomotion mode, the jump, is employed to hop one step at a time. Methods for externally tracking the Scout are developed. A large number of real-world experiments are conducted and the results discussed.

Algorithms↗

PubMed1982

[The performance of ECG telemetry in the analysis of rhythm disorders].

630 outpatients and inpatients under rest as well as under conditions of physical loads and psychic stress were examined with the help of a radiobiotelemetry device of own construction, which corresponds to a combination of traditional radiotelemetry and tape storage. In 81.4% of the patients with hitherto unclarified disturbances of the cardiac rhythm telemetry obtained their qualitative clarification. In 50% of all cases with classical angina pectoris symptomatology the ischaemic heart disease was verified by determination of the usual criterias of ECG at the telemetry stripe. Of these 50% only 7 patients had no arrhythmia. In 57.5% of all examined patients with pacemakers of permanent frequency we could prove a considerable parasystoly in load by telemetry. 9 patients with R-demand-pacemakers became evident by triggering defects in load. During the psychoanalytic examination we registered extrasystoles in 25%, apart from this once developed a pancardiac asystolism. The radiobiotelemetry is a valuable completion of the well-known methods of load.

Arrhythmias, Cardiac↗

PubMed2006

Podcasts--an emerging form of digital publishing.

Podcasting has recently emerged as an important information technology tool for health professionals and consumers around the world. Prestigious journals, international conferences, universities and government agencies among other entities are starting to publish digital informotion via audio and video podcasts. Podcosting is distinguished from other forms of digital audio-video content because it can be subscribed to (using Real Simple Syndication or RSS) and easily accessed from a personal computer. Further, it can be downloaded to a mobile device, such as an iPod where the user is able to listen to or watch it anywhere, anytime. Podcosting is used in new and evolving ways to publish information for healthcare education, patient care, professional continuing education, and in support of healthcare research. In addition to a description of what podcasting is, how podcasts are created, and how they are used, this paper addresses four critical issues that are emerging concerning podcasts. These issues are intellectual property and copyright, podcast preservation, podcast location, and podcast standards. As podcasting matures and new uses are discovered, we will see podcasting incorporated into our education, research and patient care publication paradigm.

Computers, Handheld↗

PubMed2005

Accurate data collection for head injury monitoring studies: a data validation methodology.

BACKGROUND: BrainIT is a multi centre, European project, to collect high quality continuous data from severely head injured patients using a previously defined [6] core data set. This includes minute-by-minute physiological data and simultaneous treatment and management information. It is crucial that the data is correctly collected and validated. METHODS: Minute-by-minute physiological monitoring data is collected from the bedside monitors. Demographic and clinical information, intensive care management and secondary insult management data, are collected using a handheld computer. Data is transferred from the handheld device to a local computer where it is reviewed and anonymised before being sent electronically, with the physiological data, to the central database in Glasgow. Automated computer tools highlight missing or ambiguous data. A request is then sent to the contributing centre where the data is amended and returned to Glasgow. Of the required data elements 20% are randomly selected for validation against original documentation along with the actual number of specific episodic events during a known period. This will determine accuracy and the percentage of missing data for each record. CONCLUSION: Advances in patient care require an improved evidence base. For accurate, consistent and repeatable data collection, robust mechanisms are required which should enhance the reliability of clinical trials, assessment of management protocols and equipment evaluations.

Brain Injuries↗

PubMed1985

Data acquisition and analysis of hemodynamic signals using a standard microcomputer.

Hemodynamic drug-effect studies require repetitive measurements and time-consuming calculations, particularly for the indices of left ventricular (LV) contractility and relaxation. To save time, we have created a system of acquisition, calculation, storage, and report of hemodynamic data processing E.K.G, peripheral arterial pressure, and LV pressure signals using a standard microcomputer (Apple II+) and simple accessory devices. The master program is written in BASIC Applesoft, with Mem/Dos as the disk operating system. A suite of utility routines, written in machine language, are used to program the A/D converter and to perform the vectorial calculations on the data. The software, written to process single-dose drug-effect studies, performs 1) data acquisition and storage as vectorial arrays accessible using BASIC, 2) monitor display, 3) calculations of the peripheral pressure and of the LV contractility and relaxation indices, 4) storage of the calculated indices, and 5) print-out of a report (curves and tables) at the end of each experiment and cumulated results of all the animals included in a protocol. The drawback of such a low-cost system is essentially the lack of available memory and the relatively slow speed of the microprocessor, which hinders simultaneous processing of indices needing nonlinear curve fitting and adequate print-out of protocols that are not single dose.

Animals↗

PubMed1997

Quantitative fluorescence in situ hybridization of Aureobasidium pullulans on microscope slides and leaf surfaces.

A 21-mer oligonucleotide probe designated Ap665, directed at the 18S rRNA of Aureobasidium pullulans and labelled with five molecules of fluorescein isothiocyanate, was applied by fluorescence in situ hybridization (FISH) to populations of the fungus on slides and apple leaves from growth chamber seedlings and orchard trees. In specificity tests that included Ap665 and a similarly labelled universal probe and the respective complementary probes as controls, the hybridization signal was strong for Ap665 reactions with 12 A. pullulans strains but at or below background level for 98 other fungi including 82 phylloplane isolates. Scanning confocal laser microscopy was used to confirm that the fluorescence originated from the cytoplasmic matrix and to overcome limitations imposed on conventional microscopy by leaf topography. Images were recorded with a cooled charge-coupled device video camera and digitized for storage and manipulation. Image analysis was used to verify semiquantitative fluorescence ratings and to demonstrate how the distribution of the fluorescence signal in specific interactions (e.g., Ap665 with A. pullulans cells) could be separated at a given probability level from nonspecific fluorescence (e.g., in interactions of Ap665 with Cryptococcus laurentii cells) of an overlapping population. Image analysis methods were used also to quantify epiphytic A. pullulans populations based on cell number or percent coverage of the leaf surface. Under some conditions, leaf autofluorescence and the release of fluorescent compounds by leaves during the processing for hybridization decreased the signal-to-noise ratio. These effects were reduced by the use of appropriate excitation filter sets and fixation conditions. We conclude that FISH can be used to detect and quantify A. pullulans cells in the phyllosphere.

Antibiosis↗

PubMed2006

Theoretical analysis of high-resolution digital mammography.

The performance of a high-resolution charge coupled device-based full-field digital mammography imager was analysed using a mathematical framework based on an adaptation of cascaded linear systems theory described by other investigators. This work has been conducted in order to understand the impact of various design parameters on the physical performance characteristics of the imager. Specifically, the effect of pixel size, scintillator thickness and packing density, x-ray spectra, air kerma, dark current, charge integration time, and pixel fill-factor on the frequency dependent detective quantum efficiency was studied using a charge-coupled device as a reference platform. The imaging system was modelled as a series of physical processes with gain and spatial spreading. For each stage, the signal and noise power spectra were computed and propagated through the imaging chain as inputs to subsequent stages. Good agreement between experimental and theoretical predictions was obtained for various x-ray spectral conditions that were investigated. The modulation transfer function, MTF(f) and detective quantum efficiency DQE(f) characteristics obtained in this study are encouraging and comparable to other digital mammography systems. The results of this study strongly suggest the feasibility of large area scintillator-based digital mammography imagers with pixel sizes below 100 microm.

Algorithms↗

PubMedDate not supplied

Design and implementation of a biomedical image database (BDIM).

We developed a biomedical image database (BDIM) which proposes a standardized representation of value arrays such as images and curves, and of their associated parameters, independently of their acquisition mode to make their transmission and processing easier. It includes three kinds of interactions, oriented to the users. The network concept was kept as a constraint to incorporate the BDIM in a distributed structure and we maintained compatibility with the ACR/NEMA communication protocol. The management of arrays and their associated parameters includes two distinct bases of objects, linked together via a gateway. The first one manages arrays according to their storage mode: long term storage on optionally on-line mass storage devices, and, for consultations, partial copies of long term stored arrays on hard disk. The second one manages the associated parameters and the gateway by means of the relational DBMS ORACLE. Parameters are grouped into relations. Some of them are in agreement with groups defined by the ACR/NEMA. The other relations describe objects resulting from processed initial objects. These new objects are not described by the ACR/NEMA but they can be inserted as shadow groups of ACR/NEMA description. The relations describing the storage and their pathname constitute the gateway. ORACLE distributed tools and the two-level storage technique will allow the integration of the BDIM into a distributed structure, Queries and array (alone or in sequences) retrieval module has access to the relations via a level in which a dictionary managed by ORACLE is included. This dictionary translates ACR/NEMA objects into objects that can be handled by the DBMS.(ABSTRACT TRUNCATED AT 250 WORDS)

Database Management Systems↗

PubMedDate not supplied

Comparative imaging technologies in the cardiac catheterization laboratory.

Evaluation of digital technology in the cardiac cath lab has introduced a desire to extend these technologies into electronic storage capability. Cine film is the current standard for image archiving because it meets the most important requirements of superior resolution, long-term stability, universal viewing and single-patient unit record capabilities. The major limitations of film include serial viewing (versus random access) and its incompatibility with computer techniques, such as quantitative angiography. Manufacturers and vendors have introduced several archiving alternatives that address the limitations of film. These options currently require trade offs and/or compromises in image quality, longevity, cost and numerous other requirements. Investments in alternatives should be made after comprehensive review of the expected productivity gains, anticipated media, equipment and supporting service cost improvements and prospective technological enhancements. This article has introduced a number of the issues that should be considered in comparing archiving media. As technology evolves and standards are developed, this task will become easier. In the meantime, no system to date has been able to achieve the existing advantages of film while overcoming its limitations.

Analog-Digital Conversion↗

PubMed1991

Wearable system for acquisition, processing and storage of the signal from amperometric glucose sensors.

A wearable device for the acquisition, processing and storage of the signal from needle-type glucose sensors has been designed and developed as part of a project aimed at developing a portable artificial pancreas. The device is essential to assess the operational characteristics of miniaturized sensors in vivo. It can be connected to sensors operating at a constant potential of 0.65 Volts, and generating currents in the order of 10(-9) Amp. It is screened and equipped with filters that permit data recording and processing even in the presence of electrical noise. It can operate with sensors with different characteristics (1-200 nA full scale). The device has been designed to be worn by patients, so its weight and size have been kept to a minimum (250 g; 8.5 x 14.5 x 3.5 cm). It is powered by rechargeable Ni/Cd batteries allowing continuous operation for 72 h. The electronics consists of an analog card with operational amplifiers, and a digital one with a microprocessor (Intel 80C196, MCS-96 class, with internal 16-bit CPU supporting programs written in either C or Assembler language), a 32 Kb EPROM, and an 8 Kb RAM where the data are stored. The microprocessor can run either at 5 or 10 Mhz and features on-chip peripherals: an analog/digital (A/D) converter, a serial port (used to transfer data to a Personal Computer at the end of the 72 h), input-output (I/O) units at high-speed, and two timers. The device is programmed and prepared to operate by means of a second hand-held unit equipped with an LCD display and a 16-key numeric pad.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose Self-Monitoring↗

PubMed1998

A new actigraph for long-term registration of the duration and intensity of tremor and movement.

Actigraphy, the long-term measurement of human movement with a small solid state recorder, is gaining acceptance as a useful method in many research fields. Currently available actigraphs assess or estimate the movement duration per time interval. However, the output gives no information on movement type or intensity, and cannot be used in subjects suffering from tremor. The present paper describes a new type of actigraph, that has been developed primarily for the long-term evaluation of motor symptoms in Parkinson patients. The device is the first to discriminate tremor from other movements and to assess both duration and intensity of the two types of movement. It is based on a Motorola 68HC805B6 microcontroller and contains: an accelerometer, programmable gain stages, programmable low- and highpass filters, a programmable level comparator, a peak detector, interface circuits, a real time clock, data storage, and control circuitry. The micro-controller performs a period amplitude sequence analysis (PASA) on the conditioned accelerometer signal, and stores four output variables (tremor duration, tremor amplitude, movement duration, and movement amplitude) at the end of programmable time intervals. The analysis of fluctuations in the motor symptoms of, e.g., Parkinson patients using this actigraph can be of great help in the pharmacological management of symptoms.

Aged↗

PubMed2006

Digital mammography: an update.

(1) Digital mammography can improve breast-image quality and storage through the digital capture of x-ray images. (2) Large comparative studies indicate that the overall accuracy of full-field digital mammography (FFDM) is similar to that of conventional filmscreen mammography (FSM). (3) Recent evidence suggests that FFDM is more accurate than FSM for diagnosing cancer in women younger than 50 years, those with dense breasts, and pre- or peri-menopausal women. (4) The costs of FFDM are higher than those for FSM. (5) The quality control of FFDM systems offers advantages compared to that of FSM, but it is more complex, and it is associated with a long learning curve.

Breast Neoplasms↗

PubMed2006

Hybrid data capture for monitoring patients on highly active antiretroviral therapy (HAART) in urban Botswana.

Individual patient care and programme evaluation are pivotal for the success of antiretroviral treatment programmes in resource-limited countries. While computer-aided documentation and data storage are indispensable for any large programme, several important issues need to be addressed including which data are to be collected, who collects it and how it is entered into an electronic database. We describe a patient-monitoring approach, which uses patient encounter forms (in hybrid paper + electronic format) based on optical character recognition, piloted at Princess Marina Hospital in Gaborone, Botswana's first public highly active antiretroviral therapy (HAART) outpatient clinic. Our novel data capture approach collects "key" data for tracking patient and programme outcomes. It saves physician time and does not detract from clinical care.

Antiretroviral Therapy, Highly Active↗

PubMed1995

Accuracy of caries diagnosis in digital images from charge-coupled device and storage phosphor systems: an in vitro study.

OBJECTIVES: To evaluate the diagnostic accuracy of carries detection with four intra-oral digital radiographic systems in vitro and to investigate the impact of image compression. METHODS: 116 extracted human premolars and molars mounted three in a line with approximal contacts were radiographed with four digital systems (Digora, RVG, Sens-A-Ray, and Visualix) and imported into a Windows-based program. Sixteen images from each system were compressed (JPEG, irreversible compression). The total of 528 images was assessed by six radiologists using a 5-point confidence scale for the detection of approximal and occlusal caries. Caries was validated histologically. The disease threshold was caries in enamel for approximal surfaces and in dentine for occlusal surfaces. RESULTS: Mean ROC curve areas for approximal surfaces were 0.611 (DIG), 0.572 (RVG), 0.594 (SAR), and 0.596 (VIX), and for occlusal surfaces 0.794 (DIG), 0.819 (RVG), 0.751 (SAR), and 0.761 (VIX). There were no significant differences between the areas under the ROC curves (p > 0.05); nor were there any significant differences between the compressed and uncompressed images (p > 0.05). CONCLUSIONS: The four digital systems performed almost equally well for detection of caries in vitro, and compressed images were as accurate as uncompressed.

Bicuspid↗

PubMed1996

Estimating internal dose due to ingestion of radionuclides from Nevada Test Site fallout.

The U.S. Department of Energy initiated the Radiation Exposure Review Project to provide a critical reexamination of radiation doses to people resulting from testing nuclear devices at the Nevada Test Site. One part of this effort focused on the dose resulting from the ingestion of contaminated food. The PATHWAY radionuclide transport model was developed to provide estimates of food concentrations for 20 radionuclides for each of 86 test events and 15 agricultural scenarios. These results were then used as input to the Human Ingestion model to provide dose estimates for individuals and populations in 9 western states. The model considered the life-style and age of the people, and accounted for the transport of milk between locations. Estimates of uncertainty were provided for all doses using Monte Carlo simulation techniques. Propagation of uncertainty between the PATHWAY model and the Human Ingestion model required the development of special strategies to ensure that the inherent correlations between concentrations of the radionuclides in foods were handled properly. In addition, the size of the input data base (60 megabytes), the number of cases to consider (over 30,000), and the number of Monte Carlo simulations (over 6 million) required the development of efficient and reliable methods of data access and storage while running simulations concurrently on up to 14 UNIX workstations. The problems encountered in this effort are likely to be typical of any dose reconstruction involving geographically heterogeneous environmental conditions. This paper documents the methods used to disaggregate the system to achieve computation efficiency, the methods used to propagate uncertainty through the model system, and the techniques used to manage data in a distributed computing environment. The radionuclide- and age-specific dose factors used in the analysis are also provided.

Environmental Exposure↗

PubMed1998

The effect of 10 : 1 compression and soft copy interpretation on the chest radiographs of premature neonates with reference to their possible application in teleradiology.

The aim of the study was to assess the potential application of teleradiology in the neonatal intensive care unit (NICU) by ascertaining whether any decrease in conspicuity of anatomic detail or interventional devices in the chest radiographs of premature infants is caused by picture archiving and communication system (PACS)-based soft copy interpretation of 10 : 1 compressed images. One hundred digital chest radiographs of low-birthweight infants were obtained in the NICU using a storage phosphor system. Laser-printed images were interpreted and the data set for each radiograph was then irreversibly compressed by a 10 : 1 ratio. Four radiologists with extensive PACS experience used a five-point grading system to score laser-printed hard copy images for the visibility of six parameters of anatomic landmarks and interventional devices in the chest. Compressed soft copy images displayed on 2K PACS workstation were subsequently scored using the same approach. Statistical manipulation demonstrated no loss of anatomic detail in five of the six parameters scored, with minimal difference in one landmark, the retrocardiac lung assessment. While further study is required to assess the clinical impact of the variance noted when evaluating lung parameters, the preservation or improvement of information in the remaining parameters following irreversible compression and soft copy interpretation is promising for the potential use of teleradiology in this population.

Data Interpretation, Statistical↗