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PubMed1982

A peripheralized digital image management system: prospectus.

The number of diagnostic radiology examinations being performed on digitally formatted imaging equipment is continually increasing. However, most digital data are recorded as analogue images and the films stored in a central file. The dynamic range of raw digital data is lost. Currently, the space and cost requirements for storage of all digital data have discouraged most users from attempting it. This article presents the concepts and describes the requirements and initial fabrication of a system that will capture and retain all digital data using a network of peripheralized image acquisition, display, and storage devices. Any piece of digitally formatted equipment can be interfaced into the system. A real-time computer capability provides that any digital examination can be reviewed at any display station for up to 10 days.

Computers↗

PubMed1996

Medical-legal issues in teleradiology.

With the advent of high-speed, high-resolution digital imaging and network transmission, teleradiology promises to dramatically change the mechanism for interpreting radiologic images and the traditional relationships between radiologists and patients and referring physicians. We discuss the current status of medical-legal issues pertaining to privacy, licensing, credentialing, liability, and fraud for teleradiology. Special emphasis is placed on the technical factors that may result in differences in image properties, consequently affect radiologic diagnosis, and bring the potential for liability.

Confidentiality↗

PubMed2005

If all ambulances could fly: putting provincial standards of emergency care access to the test in Northern British Columbia.

INTRODUCTION: Geographic access to emergency treatment remains an important public policy concern as rural emergency medical systems respond to various pressures to centralize services. Geographical Information Systems (GIS) are effective tools to determine what proportion of a given population is adequately served by existing or proposed service distributions. METHODS: This study compares 2 GIS approaches to determining whether recent standards of emergency care access established by the British Columbia Ministry of Health Services are being met in Northern British Columbia. In particular, we compare results obtained using the more commonly used straight-line, or "as the crow flies," method with those obtained using a more sophisticated method that estimates travel time using digitally referenced road network data. RESULTS: Both methods reveal that provincial standards of emergency access are not being met in Northern British Columbia. CONCLUSION: In terms of comparing the 2 approaches, the network technique indicated a lower level of access and was more accurate in identifying populations residing inside and outside the "golden hour" of emergency care.

Air Ambulances↗

PubMed1988

The dorsal middle phalangeal finger flap.

A versatile one-stage neurovascular flap from the dorsum of the middle phalanx of the finger is described. The flap is based on one proper digital artery, the venous network about its adventitia and the dorsal branches of the proper palmar digital nerves bilaterally. The characteristics of the flap include a size up to 3 by 6 cm, an arterio-venous pedicle up to 12 cm in length, an arc of rotation around the superficial palmar arch, discriminative sensibility, and comparably low donor morbidity. The flap may be transposed on its vascular pedicle with or without nerve suture. Furthermore it is ideally suited as a thin and pliable flow-through flap in digital replantation/revascularization. Finally, it may be utilized as a free neurovascular flap.

Adult↗

PubMed1986

Teaching with computers.

Various methods of using computers in education have been presented. Although the interesting file, interactive video, and bibliographic searches stand on their own, a far better approach is to integrate them, so that the radiologist learning new techniques in interventional procedures, for instance, could search the current literature quickly and easily for new articles using the bibliographic search facility and could review interesting cases from the teaching file that pertained to the lesson at hand. One very important attempt to integrate some of these teaching functions in conjunction with other aspects of medical school administration and research has been the Integrated Academic Information Management Systems (IAIMS) Program of the National Library of Medicine. This program stems from a report created by the Association of American Medical Colleges (AAMC), which was funded originally by the National Library of Medicine. This program has funded several teaching institutions to first plan for an integrated approach to medical information (Fig. 7) and then implement prototype systems. As medical image management systems become available (see the article entitled "Digital Image Management: Networking, Display, and Archiving"), they will be a major component of these information networks and will be most important for teaching purposes. Integrating the teaching components described earlier with the medical image management system will be most important.

Computer-Assisted Instruction↗

PubMed1996

[Research and development in medical technology industry--status in Germany].

In today's operating room, innovative methods and tools increase productivity, reduce patient trauma, and improve health care economics. Digital imaging and networking assist decision-making-practically, in real time during surgery and with 3-D reconstructions of surgical planning. The operating environment is further enhanced by nonstop monitoring and life-support equipment. Accordingly, research and clinical studies are becoming more important for medical technology assessment and thus deserve more financial support.

Clinical Trials as Topic↗

PubMed1998

[The present and future of neurophysiological examination].

This paper discusses the following routine examinations and new neurophysiological examinations that will likely be adopted in future. 1) EEG: a) The source derivation method and intracranial EEG recording method are useful for the detection of the exact focus in epileptic seizure. b) Polysomnography is applied to sleep disorders (ex. apnea syndrome). c) EEG topograph mapping and brain electric source analysis (BESA) are not only applied to neurological disorders, but also used for the detection of electrical equivalent dipole source localization. 2) Evoked potential (EP): ABR, SSEP and P-VEP by routine techniques are useful for the diagnosis of brain tumors and demyelinating diseases. Recently, event-related potential (ERP) has attracted attention in examining human recognition. 3) EMG and evoked EMG: a) MUP analysis with the template-matching method and single fiber EMG are topics of electromyography. b) M wave of evoked EMG has been used for the measurement of maximum nerve conduction velocity. Furthermore, the collision technique and microneurography can be applied to many kinds of nerves with different conduction velocities. c) The technique of magnetically stimulating the motor cortex was applied for the measurement of central motor conduction time (CMCT). 4) In the near future, neurophysiological examinations will include an EEG automatic diagnostic support system, neurophysiological network system, paperless digital EEG machine and non-invasive functional mapping with multichannel near infrared spectroscopic topography et al.

Electroencephalography↗

PubMed1994

[High-speed/high resolution teleradiology system based on university microwave network].

A high-speed, high-resolution teleradiology system with full duplexing based on the Shinshu University Video and Communication Network System (SUNS) using Giga-Herz microwaves is described. The LAN at Nagano Red-Cross Hospital and The Radiology Department of Shinshu University Hospital are interfaced to a personal computer with a laser film digitizer, interactive display, and network interface. The throughput per digitized high-resolution radiographic image was 65 sec, and the mean transmission rate was 805 kilobit per sec. Teleradiology conferencing is also possible with this system. Radiologists at both hospitals interactively observe the same high-resolution images on the CRT screen using mouse cursor synchronization.

Computer Communication Networks↗

PubMed1997

Remote connection to the Kyushu University Medical Center LAN using digital and analog telephone lines.

SOHO (Small Office/Home Office) has recently become popular, as it makes working at home possible. Computers or Local Area Networks(LAN) connected to the office network from home are necessary for the implementation of this concept. Kyushu University has begun a service connecting home computers to the campus LAN for researchers, staff and students of the Faculty of Medicine. We have two different telephone connection methods. One connects the campus LAN and the home computer LAN using routers through the Integrated Services Digital Network (ISDN). The other connects computers at home to the workstation in the university, using modems and the PPP (Point to Point Protocol) through a public telephone analog line. This paper outlines our university SOHO connection system and discusses the merits and demerits of using telephone line connections.

Academic Medical Centers↗

PubMed1986

Re-evaluation of the classical acupuncture concept of meridians in Oriental medicine by the new method of detecting meridian-like network connected to internal organs using "Bi-Digital O-Ring Test".

"Bi-Digital O-Ring Test" has been successfully applied clinically as one of the simplest non-invasive, safe early diagnostic methods as well as localizing specific substances and neuro transmitters and tissues by the " 'Bi-Digital O-Ring Test' Molecular Identification and Localization Method". Using the method most of the internal organs it becomes possible to image the outline of most of the internal organs on most of the body surface without exposing the patient to undesirable radiation of X-Ray or strong magnetic field. While imaging outline of the internal organs the author found that from the surface of each organ, lines or networks of lines extending to the other parts of the body. Such a line closely resembled classically well known lines of meridians of major internal organs in Oriental medicine which author named meridian-like network of each internal organ. Each internal organ's meridian-like network usually can be imaged using microscopic slide of tissue or tissue itself. However, entire part of the small intestine meridian in the arm can also be imaged by heart tissue. For example "spleen meridian" has been considered to represent mainly pancreas of the western medical concept and this was also confirmed by the fact that using microscopic slide of pancreas or dessicated tissue of the pancreas well-known spleen meridian-like network can be imaged. The author also confirmed some of the description of the direction of the meridian and direction of the in reference to the direction of the insertion of the acupuncture needle. The width of the line of this meridian-like network was usually within one or two millimeters and one millimeter outside of the line do not have the same characteristics. This meridian-like network seems to be specialized channel which can propagate some type of information in electro-magnetic field to regulate some of the body functions throughout the body which is difficult to explain in current western medical anatomical concept.

Acupuncture Therapy↗

PubMed1995

[Digital picture archiving, processing and communication in diagnostic imaging with a Siemens Network (SIENET): initial results].

The concept of Picture Archiving and Communication System (PACS) in digital imaging offers substantial advantages: better data security, faster access to archived images, simultaneous availability of images at different sites, minimal space demand for archive medium, retrospective image post-processing opportunities and lower costs resulting from reduced film consumption and length of stay. However, practical experiences concerning reliability and efficiency of real PAC networks in radiological departments have to be made yet in order to improve network structure, software design and hardware performance. The ongoing stepwise installation and test of a Siemens PACS (SIENET) at the Department of Radiology at the Medical University of Lübeck will support the introduction of PACS concept into radiological practice.

Computer Communication Networks↗

PubMed2001

Quantitative 3-dimensional profiling of channel networks within transparent lab-on-a-chip microreactors using a digital imaging method.

We have developed a method for the quantitative 3-dimensional profiling of micron sized channel networks within optically transparent "lab-on-a-chip" microreactor devices. The method involves capturing digitised microscope images of the channel network filled with an optically absorbing dye. The microscope is operated in transmission mode using light filtered through a narrow bandpass filter with a maximum transmission wavelength matching the wavelength of the absorbance maximum of the dye solution. Digitised images of a chip filled with solvent and dye solution are analysed pixel by pixel to yield a spatially resolved array of absorbance values. This array is then converted to optical path length values using the Beer-Lambert law, thereby providing the 3D profile of the channel network. The method is capable of measuring channel depths from 10 to 500 microm (and probably even smaller depths) with an accuracy of a few percent. Lateral spatial resolution of less than 1 microm is achievable. It has been established that distortion of the measured profiles resulting from a mismatch in refractive index between the dye solution and the glass of the microreactors is insignificant. The method has been successfully used here to investigate the effects of thermal bonding and etch time on channel profiles. The technique provides a convenient, accurate and non-destructive method required to determine channel profiles; information which is essential to enable optimisation of the operating characteristics of microreactor devices for particular applications.

Journal Article↗

PubMed2004

Early detection of diabetes retinopathy by new algorithms for automatic recognition of vascular changes.

Diabetes mellitus often results in diabetic retinopathy caused by pathological changes of the retinal vessel tree. Early detection of these changes can delay the disease. Image processing can reduce the workload of screeners and can play a central role in quality assurance tasks. Therefore we aimed at the refinement and development of image processing algorithms to improve the quality and cost effectiveness of screening and diagnosis of diabetic retinopathy. In order to support ophthalmologists in their routine and to enable the quantitative assessment of vascular changes in colour fundus photographs a multi-resolution approach was developed which segments the vessel tree efficiently and precisely into digital images of the retina. The vessel tracker aims at determining as correctly as possible the retinal vascular network captured on a digital image irrespective of its origin. In addition to the tracker, algorithms were developed to detect the optic disk, bright lesions such as cotton wools spots, and dark lesions such as haemorrhages. The following classification of veins and arteries identifies arteries in 78.4 % and veins in 66.5% correctly. This helps selecting conspicuous images from a great number of patients.

Algorithms↗

PubMed1984

Cognitive arithmetic: comparison of operations.

Adults' performance of simple arithmetic calculations (addition, multiplication, and numerical comparison) was examined to test predictions of digital (counting), analog, and network models. Although all of these models have been supported by studies of mental addition, each leads to a different prediction concerning relations between the times required for addition, multiplication, and numerical comparison. Pairs of single-digit integers were presented and reaction times (RTs) for adding, multiplying, and comparing the stimuli were collected. A high correlation between RT for addition and multiplication of the same digits was obtained. This result is consistent with a network model, but presents difficulties for both analog and counting models. A "ties" effect of no increase in RT with increases in problem size for doubles such as 2 + 2 has been found in previous studies of addition using verification procedures, but was not found with the production task employed in the present study. Instead, a different kind of ties effect was found. Reaction time for both addition and multiplication of ties increased more slowly with problem size than did RT for non-tie problems. This ties effect, and the finding that probability of making errors contributes independently of problem size to RT support a distinction between location and accessibility of information in a network.

Adult↗

PubMed1993

Evaluation of a neural network model of amnesia in diffuse cerebral atrophy.

A digital computer program generating a simulated neural network was used to construct a model which can show behaviour resembling human associative memory. The experimental network uses distributed storage, and, in this respect, its functional organisation resembles that suggested by reported observations of neuronal activity in the human temporal lobe during memory storage and recall. Inactivation of increasing numbers of randomly distributed network units simulated advancing cerebral atrophy. This caused progressive impairment of performance, resembling the gradual deterioration of memory function observed in chronic diffuse cerebral degeneration. Unit inactivation had similar effects on recall whether the same units were inactivated before or after learning. This differs from most relevant observations of amnesia resulting from diffuse cerebral disease. While the model may functionally resemble long-term information storage sites in the brain, other cerebral mechanisms participating in learning and remembering are also damaged by diffuse cerebral atrophy.

Amnesia↗

PubMed2005

Tumor neocapillary density in hepatocellular carcinoma cells implanted nude mice model.

Tumor angiogenesis is an important process for several kinds of tumor, especially, during its angiogenic switch. The present study was aimed to investigate the dynamical process of tumor neocapillarization in Hepatocellular carcinoma cells implanted nude mice model. Male BALB/c nude mice (20-25 g) were used. After the implantation of a dorsal skin-fold chamber, the Hepatocellular carcinoma cells (HepG2) (30 microl of 2 x 10(6) cells) were inoculated into the upper layer of the skin within the chamber (HepG2-group), while the shammed control group (Sham-group) was received a normal saline. Intravital fluorescence videomicroscopy was performed to monitor the tumor neocapillary on days 7 and 14 post-inoculation by intravenous injection of 0.1 ml rhodamine B isothiocyanate-labeled dextran (0.5%). Based on the recorded videoimages, the tumor microvascular networks were measured using a digital image analysis. The neovascular density and configuration were represented in terms of microvascular density index (MVDI) and neovascular bifurcation ratio (BR). The MVDI levels of HepG2-group were significantly increased on day 7 and 14 compared to the age-matched Sham-group. The increase in MVDI agreed with the increase in the BR. In conclusion, our dorsal skin-fold chamber technique with intravital fluorescence videomicroscopy and digital image analysis was most useful to monitor the neovascular network for quantitatively evaluating the progression of tumor angiogenesis in terms of MVDI and BR values.

Animals↗

PubMedDate not supplied

Development of an electronic radiologist's office in a private institute.

A computer system that improves the quality, user-friendliness, accessibility, and management of radiology data (images, reports, databases, knowledge) was implemented at a private institute. A picture archiving and communication system (PACS) was integrated with the radiology information system (RIS). Two servers and 12 personal computers form the integrated system. The first server is dedicated to management and archiving of Digital Imaging and Communications in Medicine (DICOM) images. The second server is dedicated to management of the RIS and archiving of patient data (Structured Query Language database), reports (hypertext markup language [HTML]), and images in the Joint Photographic Experts Group (JPEG) format (mini-PACS). There are three main client-server networks: a common network of imaging modalities (magnetic resonance imaging, computed tomography, ultrasonography, digital radiography) and two fast Ethernet networks (the PACS network and the RIS network). The RIS-PACS is linked remotely with other workstations and servers via Integrated Services Digital Network (ISDN). Images and reports can be distributed to referring physicians in the form of multimedia HTML and JPEG documents, which can also be used for quick and easy archiving, distribution, and reviewing within the institute. However, referring physicians have been reluctant to use electronic reports and images.

Attitude of Health Personnel↗

PubMed2005

Calibration of a Hall effect displacement measurement system for complex motion analysis using a neural network.

Biomechanics studies often require the analysis of position and orientation. Although a variety of transducer and camera systems can be utilized, a common inexpensive alternative is the Hall effect sensor. Hall effect sensors have been used extensively for one-dimensional position analysis but their non-linear behavior and cross-talk effects make them difficult to calibrate for effective and accurate two- and three-dimensional position and orientation analysis. The aim of this study was to develop and calibrate a displacement measurement system for a hydraulic-actuation joystick used for repetitive motion analysis of heavy equipment operators. The system utilizes an array of four Hall effect sensors that are all active during any joystick movement. This built-in redundancy allows the calibration to utilize fully connected feed forward neural networks in conjunction with a Microscribe 3D digitizer. A fully connected feed forward neural network with one hidden layer containing five neurons was developed. Results indicate that the ability of the neural network to accurately predict the x, y and z coordinates of the joystick handle was good with r(2) values of 0.98 and higher. The calibration technique was found to be equally as accurate when used on data collected 5 days after the initial calibration, indicating the system is robust and stable enough to not require calibration every time the joystick is used. This calibration system allowed an infinite number of joystick orientations and positions to be found within the range of joystick motion.

Algorithms↗