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Biomedical subjects

R E Dayhoff

Publications and source records attributed to R E Dayhoff.

15 recordsLinked to original sources
PubMed1992

Exchange of Veterans Affairs medical data using national and local networks.

Remote data exchange is extremely useful to a number of medical applications. It requires an infrastructure including systems, network and software tools. With such an infrastructure, existing local applications can be extended to serve national needs. There are many approaches to providing remote data exchange. Selection of an approach for an application requires balancing of various factors, including the need for rapid interactive access to data and ad hoc queries, the adequacy of access to predefined data sets, the need for an integrated view of the data, the ability to provide adequate security protection, the amount of data required, and the time frame in which data is required. The applications described here demonstrate new ways that the VA is reaping benefits from its infrastructure and its compatible integrated hospital information systems located at its facilities. The needs that have been met are also needs of private hospitals. However, in many cases the infrastructure to allow data exchange is not present. The VA's experiences may serve to establish the benefits that can be obtained by all hospitals.

CD-ROM↗
PubMed1992

A bidirectional ACR-NEMA interface between the VA's DHCP Integrated Imaging System and the Siemens-Loral PACS.

There is a wide range of requirements for digital hospital imaging systems. Radiology needs very high resolution black and white images. Other diagnostic disciplines need high resolution color imaging capabilities. Images need to be displayed in many locations throughout the hospital. Different imaging systems within a hospital need to cooperate in order to show the whole picture. At the Baltimore VA Medical Center, the DHCP Integrated Imaging System and a commercial Picture Archiving and Communication System (PACS) work in concert to provide a wide-range of departmental and hospital-wide imaging capabilities. An interface between the DHCP and the Siemens-Loral PACS systems enables patient text and image data to be passed between the two systems. The interface uses ACR-NEMA 2.0 Standard messages extended with shadow groups based on draft ACR-NEMA 3.0 prototypes. A Novell file server, accessible to both systems via Ethernet, is used to communicate all the messages. Patient identification information, orders, ADT, procedure status, changes, patient reports, and images are sent between the two systems across the interface. The systems together provide an extensive set of imaging capabilities for both the specialist and the general practitioner.

Data Display↗
PubMed1992

An integrated multidepartmental hospital imaging system: usage of data across specialties.

Development of automated medical information systems requires knowledge about the utilization of the system; both for design and as feedback during the development process. One of the significant advantages of computer systems is that they can provide an automatic log of system utilization. This paper reports the first study of utilization data collected automatically in an integrated image environment. System monitoring indicates that images are routinely used in clinical care and clinical conferences. Selected images are shown repeatedly for teaching, demonstration, and reference at locations throughout the hospital. Images are viewed both by the collecting service when producing procedure reports and consultations, as well as by the treating physicians from other hospital services. Medical departments have developed image collection policies to meet their internal needs and the needs of treating physicians.

Hospital Information Systems↗
PubMed1992

VA's Integrated Imaging System on three platforms.

The DHCP Integrated Imaging System provides users with integrated patient data including text, image and graphics data. This system has been transferred from its original two screen DOS-based MUMPS platform to an X window workstation and a Microsoft Windows-based workstation. There are differences between these various platforms that impact on software design and on software development strategy. Data structures and conventions were used to isolate hardware, operating system, imaging software, and user-interface differences between platforms in the implementation of functionality for text and image display and interaction. The use of an object-oriented approach greatly increased system portability.

Computer Graphics↗
PubMed1991

Integrating medical images into hospital information systems.

The effective delivery of health care has become increasingly dependent on a wide range of medical data that includes a variety of images. Manual and computer-based medical records ordinarily do not contain image data, leaving the physician to deal with a fragmented patient record widely scattered throughout the hospital. The Department of Veterans Affairs is currently installing a prototype hospital information system workstation network to demonstrate the feasibility of providing image management and communications functionality as an integral part of an existing hospital information system. The core of this system is a data base management system adapted to handle images as a new data type. A general model for this network-based integration is discussed and various alternative architectures are examined.

Database Management Systems↗
PubMed1991

Providing an integrated clinical data view in a hospital information system that manages multimedia data.

The VA's hospital information system, the Decentralized Hospital Computer Program (DHCP), is an integrated system based on a powerful set of software tools with shared data accessible from any of its application modules. It includes many functionally specific application subsystems such as laboratory, pharmacy, radiology, and dietetics. Physicians need applications that cross these application boundaries to provide useful and convenient patient data. One of these multi-specialty applications, the DHCP Imaging System, integrates multimedia data to provide clinicians with comprehensive patient-oriented information. User requirements for cross-disciplinary image access can be studied to define needs for similar text data access. Integration approaches must be evaluated both for their ability to deliver patient-oriented text data rapidly and their ability to integrate multimedia data objects. Several potential integration approaches are described as they relate to the DHCP Imaging System.

Computer Communication Networks↗
PubMed1984

Quantitative histochemical measurement of GABA-transaminase: method for evaluation of intracerebral lesions produced by excitotoxic agents.

GABA-transaminase (GABA-T) activity of fresh frozen coronal sections through rat striatum was evaluated 4-6 weeks after intrastriatal application of kainic or ibotenic acid. 16 micrograms sections were processed for GABA-T histochemistry and were evaluated quantitatively by computerized densitometry using image analysis. Alternate sections (200 micrograms) were assayed for GABA-T activity in vitro. Gross examination of sections stained for GABA-T revealed obvious lack of staining in the vicinity of lesions produced by either kainate (0.5-1.0 micrograms) or ibotenate (10-20 micrograms); the extent of each lesion was clearly delineated by the stain. Quantitative analysis of stained sections revealed that the lesioned tissue contained 80-90% less GABA-T activity than control tissue. This loss of GABA-T was in agreement with values obtained in adjacent sections assayed in vitro. Similar studies in substantia nigra clearly and quantitatively demonstrated damage induced by ibotenate or kainate in this nucleus as well as in tissue in the overlying reticular formation. Moreover, two compartments of GABA-T were discriminated in substantia nigra: one associated with neural perikarya, which was sensitive to kainic and ibotenic acids (80% of total GABA-T), and a second associated with afferent terminals arising from forebrain projections (20%). Thus, after destruction of neurons with kainic or ibotenic acid, GABA-T activity is largely eliminated. Under these conditions, it appears that glia contribute relatively little to the GABA-T activity measured either histochemically or by direct chemical assay in homogenates.

4-Aminobutyrate Transaminase↗
PubMed1984

Aldehyde-induced platelet aggregation.

Formaldehyde, acetaldehyde, malondialdehyde, glutaraldehyde and paraldehyde, when added in vitro to platelet-rich plasma, generate a similar distinct platelet aggregation response which is dose dependent when measured with a manual visual microscopic technique and by computerized image analysis, 'computerized platelet aggregation analysis'. Light transmission aggregometry did not measure this aggregation in a reliable manner. The aggregating reaction was specific to the aldehyde group and was not seen when the aldehyde was replaced by an alcohol, ketone, or acetate group in the case of acetaldehyde. The maximal aggregating effect of these aldehydes was directly proportional to the number of aldehyde groups per molecule. Aggregation was found to require the presence of plasma, but not von Willebrand's factor.

Acetaldehyde↗
PubMed1981

Liability for personal injuries caused by defective medical computer programs.

During the past ten years, the use of computer programs in medicine has become increasingly prevalent. As these programs proliferate, however, their potential to injure patients also increases. Although the question of liability for personal injuries caused by defective medical computer programs has not been addressed by the courts, it is inevitable that this question will arise in a judicial forum. In this Article, the authors examine the questions a court will face when addressing this novel cause of action. They attempt to resolve some of these questions by exploring the relevant characteristics of medical computer programs and examining their relationship to the tort law doctrines of negligence and strict products liability. The authors conclude that medical computer programs will be treated as products by the courts, subjecting their manufacturers to strict liability in tort for any defects in the program that cause injury. As a result, the authors contend, hospitals are likely to face a new source of liability for patient injuries if, under the particular circumstances, they are deemed to be the manufacturer or the distributor of a medical computer program that causes an injury.

Computers↗