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PubMed1995

Using JPEG image compression to facilitate telemedicine.

Economical applications of teleradiology and telemedicine are limited to the existing telephone network infrastructure, which greatly limits the speed of digital information transfer. Telephone lines are inherently slow, requiring image transmission times to be unacceptably long for large, complex, or numerous images. JPEG (Joint Photographic Experts Group) image transmission has been shown to compress images to 10% of the original file size without a noticeable change in the quality of the image. This study was carried out to assess the quality of medical diagnostic images after JPEG compression and decompression. X-rays, computed tomography scans, and ultrasound samples were compressed and decompressed using JPEG. The compressed JPEG images were indistinguishable from the original images. The JPEG images were approximately 10% of the original file size. This would reduce image transmission times by 90% (eg, an unacceptable time of 50 minutes would be reduced to an acceptable time of 5 minutes). JPEG can be used to optimize teleradiology and telemedicine.

Humans↗
PubMed2005

Digital image processing-an alternate tool for monitoring of pigment levels in cultured cells with special reference to green alga Haematococcus pluvialis.

A method for analyzing carotenoid content in Haematococcus pluvialis, a green alga was developed using digital image processing (DIP) and an artificial neural network (ANN) model. About 90 images of algal cells in various phases of growth were processed with the tools of DIP. A good correlation of R(2)=0.967 was observed between carotenoid content as estimated by analytical method and DIP. Similar correlation was also observed in case of chlorophyll. Since the conventional methods of carotenoid estimation are time consuming and result in loss of pigments during analysis, DIP method was found to be an effective online monitoring method. This method will be useful in measurement of pigments in cultured cells.

Algorithms↗
PubMed2005

The development of a nonintrusive home-based physiologic signal measurement system.

This paper describes the development of a nonintrusive health-monitoring house system that has been developed for monitoring patients' health status. The system functions unobtrusively and leaves patients free to conduct daily activities. Installed sensors and devices in the house monitor biosignals such as bedside electrocardiogram (ECG), snoring, weight, and movement pattern. The network in the house was constructed using asymmetric digital subscriber line (ADSL) and Bluetooth technologies and it is capable of transmitting monitored signals to the remote hospital server through the home server. The system is found to be effective in monitoring patients' daily activity and health status in a nonconstraining manner.

Adult↗
PubMed1991

Expert learning system network for diagnosis of breast calcifications.

Breast calcification diagnosis was studied by using clinical findings and computerized image processing of a mammogram in a network of trained expert learning systems (Outcome Advisor [OA]). The system was tested with records not used for training and performance was compared with radiologist. The network was 72% accurate in classifying clusters of calcifications as malignant or benign over a set of test cases radiologists had considered "hard-to-diagnose calcifications," and referred for biopsy. The radiologists had decided to conduct biopsy by selecting an equal number of positive and negative cases for the test group; thus the radiologists' performance with respect to categories of benign versus malignant was constrained to be 50/50. Statistical analysis shows only a 2% probability that the observed accuracy of 72% was a chance performance in recognizing whether a cluster is benign or malignant. The feasibility of developing a network of OAs for diagnosing breast cancer integrating digital image processing of mammograms is promising.

Breast Diseases↗
PubMedDate not supplied

Technology's implications for health care quality. A clinical engineering perspective.

Bill Gates states in Business @ The Speed of Thought that "the 2000s will be about velocity." This "decade of velocity" is driven by the flow of digital information. Health care organizations should develop a "digital nervous system" that is distinguished from a network of computers by the accuracy, immediacy, and richness of the information it brings to health care workers and by the insight and collaboration made possible by this information. This article provides a clinical engineering perspective on technology in health care in an era of rapid change. It discusses how clinical engineers work with health care professionals to manage and adapt to technological, economic, social, and regulatory forces that are redefining our approach to health care delivery.

Biomedical Engineering↗
PubMed2004

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↗
PubMed2005

Ultrasound research scanner for real-time synthetic aperture data acquisition.

Conventional ultrasound systems acquire ultrasound data sequentially one image line at a time. The architecture of these systems is therefore also sequential in nature and processes most of the data in a sequential pipeline. This often makes it difficult to implement radically different imaging strategies on the platforms and makes the scanners less accessible for research purposes. A system designed for imaging research flexibility is the prime concern. The possibility of sending out arbitrary signals and the storage of data from all transducer elements for 5 to 10 seconds allows clinical evaluation of synthetic aperture and 3D imaging. This paper describes a real-time system specifically designed for research purposes. The system can acquire multichannel data in real-time from multi-element ultrasound transducers, and can perform some real-time processing on the acquired data. The system is capable of performing real-time beamforming for conventional imaging methods using linear, phased, and convex arrays. Image acquisition modes can be intermixed, and this makes it possible to perform initial trials in a clinical environment with new imaging modalities for synthetic aperture imaging, 2D and 3D B-mode, and velocity imaging using advanced coded emissions. The system can be used with 128-element transducers and can excite 128 transducer elements and receive and sample data from 64 channels simultaneously at 40 MHz with 12-bit precision. Two-to-one multiplexing in receive can be used to cover 128 receive channels. Data can be beamformed in real time using the system's 80 signal processing units, or it can be stored directly in RAM. The system has 16 Gbytes RAM and can, thus, store more than 3.4 seconds of multichannel data. It is fully software programmable and its signal processing units can also be reconfigured under software control. The control of the system is done over a 100-Mbits/s Ethernet using C and Matlab. Programs for doing, e.g., B-mode imaging can be written directly in Matlab and executed on the system over the net from any workstation running Matlab. The overall system concept is presented along with its implementation and examples of B-mode and in vivo synthetic aperture flow imaging.

Analog-Digital Conversion↗
PubMedDate not supplied

Dose anisotropy around an Au-198 seed source.

For interstitial implants with radioactive Au-198 seeds, the dosimetric calculations usually ignore the finite source size and employ a point source approximation, resulting in a computed isotropic dose distribution. However, the measured radiation fluence from Au-198 seeds is reported to be anisotropic, suggesting some amount of dose anisotropy in tissue. We have measured this dose anisotropy around Au-198 seeds (2.5 X 0.8 mm2) using Kodak X-OMAT XV-2 films placed in contact with individual seeds in a phantom. Autoradiographs obtained for various exposure times were digitized and studied with an image analysis computer network. The network's overall spatial resolution was about 0.01 cm. The optical isodensity contours around the seed were obtained. The useful range of optical density (OD) for the system was found to be 1 to 2 OD units. Within this range, the shape of an optical isodensity contour would be identical to an isodose contour. Proximal to the source, the contours were elliptical in shape, elongated along the seed axis. However, further away, the elongation was in the direction normal to the seed axis. This was in agreement with the reported data on the radiation fluence around Au-198 seeds. It was concluded that measurable dose anisotropy existed around Au-198 seeds. However, it was too small to be of any clinical significance.

Brachytherapy↗
PubMed2003

The informatics of a C57BL/6J mouse brain atlas.

The Mouse Atlas Project (MAP) aims to produce a framework for organizing and analyzing the large volumes of neuroscientific data produced by the proliferation of genetically modified animals. Atlases provide an invaluable aid in understanding the impact of genetic manipulations by providing a standard for comparison. We use a digital atlas as the hub of an informatics network, correlating imaging data, such as structural imaging and histology, with text-based data, such as nomenclature, connections, and references. We generated brain volumes using magnetic resonance microscopy (MRM), classical histology, and immunohistochemistry, and registered them into a common and defined coordinate system. Specially designed viewers were developed in order to visualize multiple datasets simultaneously and to coordinate between textual and image data. Researchers can navigate through the brain interchangeably, in either a text-based or image-based representation that automatically updates information as they move. The atlas also allows the independent entry of other types of data, the facile retrieval of information, and the straight-forward display of images. In conjunction with centralized servers, image and text data can be kept current and can decrease the burden on individual researchers' computers. A comprehensive framework that encompasses many forms of information in the context of anatomic imaging holds tremendous promise for producing new insights. The atlas and associated tools can be found at http://www.loni.ucla.edu/MAP.

Anatomy, Artistic↗
PubMed1997

Advances in digital video for electronic media.

From media's early days of film strips and records, to today's multimedia CD-ROMs, nurses have embraced educational tools. Today, the capabilities of these tools have placed a tremendous demand for providing information any time, any where. This has led to increasing digitization of sights and sounds. Once digitized, this information can travel over information highways made up of telephone lines, fiberoptic cables, microwaves and satellites, or it can be stored on magnetic and optical media. Technological advances have made it possible for computer users to create, store and retrieve high quality digital still and moving video and audio for inclusion in electronic media. Methods for digitizing include capturing and converting the information with cameras, scanners and capture boards. Digital video compression/decompression (codec) standards vary in quality. Potential uses of digital video abound including video on demand, videoconferencing, distance learning, telemedicine, on-line education and computer-based training. Examples illustrating the differences in digital video formats will be shown during the presentation.

Analog-Digital Conversion↗
PubMed1999

[The design and implement of PACS components in digital imaging apparatus].

The domestic application of PACS will surely be developed in the future, but it will still take a few years. This paper proposes a tradeoff scheme: Attaching to digital imaging apparatus the PACS components, which mainly contain the Auto-archiving unit, the Communication unit supporting WAN as well as LAN and the Converting Interface unit to the hospital PACS. In this way, a single digital imaging apparatus can archive and transmit data independently, also can merge with the hospital PACS conveniently in the future. In this paper, both the design and the implement are discussed in detail.

Angiography, Digital Subtraction↗
PubMed1995

Haematological cytology image bank and teletransmission for microscopic diagnosis.

Video recording of microscopic preparations, digitalization and storage, transmission by a specialized telephone network are revolutionizing microscopic diagnosis procedures. Adjustment of standardization of medical diagnosis, based on internationally recognized classifications and their computerized coding are fundamental to this process (ADICAP coding system). We are evaluating telediagnosis procedure to test their relevance in practical hematology. Taking into account clinical and biological informations is necessary to deal with difficult cases, in using in addition to microscopic observations, a compromise of analytic data which must be rapidly available in a data bank by cross references research. In comparison with other pathological applications, the sampling problem is specially crucial in hematologic cases, for which it is necessary to observe at high resolution a fairly high number of microscopic fields, from the peripheral blood and bone marrow smears, in addition to samples of histopathologic sections from bone marrow and/or lymph-node. A previous teleconsultation of an extensive data bank appears as being one of the best way to reduce the procedure of telediagnosis to the only difficult cases, for which clear responses cannot be found in the data bank. A link between the access to the data bank and the telediagnosis procedures appears to be a fundamental approach. Our first experience shown us that a mean of 10 to 15 observed fields are necessary to conclude in ordinary cases (i.e. peripheral blood of lymphoproliferative disorders), while up to 30 fields or more are sometimes necessary for complex cases (acute leukemias, myelodysplastic and myeloproliferative syndromes), including cytologic and histopathologic data from the peripheral blood, bone marrow, lymph nodes.

Computer Communication Networks↗
PubMed2001

What Digital Imaging and Communication in Medicine (DICOM) could look like in common object request broker (CORBA) and extensible markup language (XML).

Common object request broker architecture (CORBA) is a method for invoking distributed objects across a network. There has been some activity in applying this software technology to Digital Imaging and Communications in Medicine (DICOM), but no documented demonstration of how this would actually work. We report a CORBA demonstration that is functionally equivalent and in some ways superior to the DICOM communication protocol. In addition, in and outside of medicine, there is great interest in the use of extensible markup language (XML) to provide interoperation between databases. An example implementation of the DICOM data structure in XML will also be demonstrated. Using Visibroker ORB from Inprise (Scotts Valley, CA), a test bed was developed to simulate the principle DICOM operations: store, query, and retrieve (SQR). SQR is the most common interaction between a modality device application entity (AE) such as a computed tomography (CT) scanner, and a storage component, as well as between a storage component and a workstation. The storage of a CT study by invoking one of several storage objects residing on a network was simulated and demonstrated. In addition, XML database descriptors were used to facilitate the transfer of DICOM header information between independent databases. CORBA is demonstrated to have great potential for the next version of DICOM. It can provide redundant protection against single points of failure. XML appears to be an excellent method of providing interaction between separate databases managing the DICOM information object model, and may therefore eliminate the common use of proprietary client-server databases in commercial implementations of picture archiving and communication systems (PACS).

Computer Communication Networks↗
PubMed1991

Digital chest radiography.

It is apparent that digital radiography holds considerable promise. Although there are some immediate advantages to be gained from using digital technology at present, such as more consistent image quality in portable radiography, most of the benefits have not been fully realized. To do so requires a completely integrated digital radiology department using high-resolution video displays throughout the hospital connected to a large digital image archiving system. This concept, referred to as picture archiving and communication systems (PACS), represents the logical culmination of the extensive research that is continuing in this area. Because of the great expense involved, it is likely that the transition from conventional to digital radiography will be evolutionary in most medical centers, with establishment of local PACS networks initially, such as between the intensive care units and the radiology department. At a more basic level, limited digital radiography systems can function in isolation and address specific needs successfully. Although the science of computer-aided diagnosis is at an early stage, it seems likely that the sensitivity and specificity of these programs will continue to improve. Their eventual utility will depend on their accuracy and ease of use. The ultimate goal would be a relatively "transparent" multifaceted program that would screen all radiographs prior to interpretation to provide the radiologist or clinician with diagnostic suggestions and quantitative data. Given the present rate of progress in this area, such a concept is not unrealistic. However, even the most ardent enthusiasts do not envision totally independent computer-based interpretation of radiographic images for some time. Although digital image processing has not greatly improved diagnostic accuracy merely by enhancing the appearance of the radiographs, there are other potential diagnostic advantages in using digital images, such as rapid retrieval of previous examinations and the ability to correlate chest radiographs with CT or MRI studies rapidly on a video display. Direct image correlation with registration and superimposition has been achieved in the case of positron-emission tomography and MRI studies of the brain. For chest radiograph examinations, superimposition and subtraction of earlier radiographs to enhance the detection of interval change is being studied. The question of when digital chest radiography will replace conventional imaging is controversial. In a recent multiauthored review of this subject, it was estimated that digital chest radiography will replace conventional film radiography in at least 50% of large teaching hospitals by the turn of the century.(ABSTRACT TRUNCATED AT 400 WORDS)

Diagnosis, Computer-Assisted↗
PubMed1999

Boosted mixture of experts: an ensemble learning scheme.

We present a new supervised learning procedure for ensemble machines, in which outputs of predictors, trained on different distributions, are combined by a dynamic classifier combination model. This procedure may be viewed as either a version of mixture of experts (Jacobs, Jordan, Nowlan, & Hintnon, 1991), applied to classification, or a variant of the boosting algorithm (Schapire, 1990). As a variant of the mixture of experts, it can be made appropriate for general classification and regression problems by initializing the partition of the data set to different experts in a boostlike manner. If viewed as a variant of the boosting algorithm, its main gain is the use of a dynamic combination model for the outputs of the networks. Results are demonstrated on a synthetic example and a digit recognition task from the NIST database and compared with classifical ensemble approaches.

Algorithms↗
PubMed2003

Patient confidentiality, data security, and provider liabilities in diabetes management.

From inception, the electronic patient record has raised issues of data protection and patient confidentiality. These privacy issues have become more complicated with the introduction of electronic links to patient information held in databases sited on local and wide area networks. The first purpose of this paper is to review, from the provider's perspective, the issues surrounding patient confidentiality, data security, and consequential provider liabilities. The second is to propose possible immediate strategies and long-term solutions. Clinical procedures in diabetes practice create patient data from confidential information. This information is owned by the patient, received by the provider, enriched by a professional interpretation, and merged with other data into health records. Ownership, privacy, accountability, and responsibility issues are raised. Consequential data security and patient privacy are easily met by storage in a locked box or file cabinet. Conversion of such records into digital data in databases on local and wide area networks markedly increases the provider's exposure to liabilities. Current methods for securing remote data exist. These involve user authentication and secure transmission, but remote data storage is far less secure than a locked box. New tools for the secure storage of patient data are outlined. These involve encryption and decryption by the provider alone. A suite of computer protocols is presented that can restore security equivalent to a "locked box" and thus reduce liabilities for the provider. Providers should protect the privacy of their patients by encrypting all data that are stored in remote repositories. The tools to do this are urgently needed. A standardized digital protocol for verifying user identities, preserving patient confidentiality, and controlling data security by encryption will fully mitigate provider liabilities. Standardization and economies of scale promise future cost containment.

Confidentiality↗