bluuebunny/crossref_metadata_2025_split huggingface dataset:
NMR Imaging
Authors: Moratal David , Brummer Marijn E. , Martí-Bonmatí Luis , Vallés-Lluch Ana 
Published: April 2006

Abstract
In 1946, the phenomenon of nuclear magnetic resonance (NMR) was first observed independently by Felix Bloch and Edward Purcell. NMR is a phenomenon exhibited by atoms with an odd number of protons or neutrons which possess nuclear spin angular momentum. In the classical description the phenomenon can be described as spinning charged spheres which produce a small magnetic moment. Developments in NMR over the decades that followed, including the spin echo and different RF pulse sequences, led to widespread use of NMR spectroscopy, a method of analyzing the composition of chemical samples. In 1970, Raymond Damadian discovered the basis for using NMR as a tool for in‐vivo cancer diagnosis. In 1973, Paul Lauterbur proposed the use of gradient magnetic fields for spatial encoding of NMR signals to form the first magnetic resonance images. Magnetic resonance imaging (MRI) has since developed rapidly into a widely used clinical imaging modality, and is now used to image virtually every part of the body in clinical practice. MRI has the important advantage over X‐ray imaging modalities that it does not use ionizing radiation. MRI also allows arbitrary selection of the scan plane and true three‐dimensional imaging. Unlike any other medical imaging modalities, image contrast in MRI is based on multiple physical parameters, resulting in the unique ability to generate excellent soft‐tissue contrast that can be tailored for specific applications.
Nonionizing Radiation
Authors: Wood Andrew 
Published: April 2006

AbstractNonionizing radiation (NIR) refers to that part of the electromagnetic spectrum with wavelength greater than approximately 100 nm. It is customary to include static electric and magnetic fields under the heading of NIR, and some include ultrasound. When compared with ionizing radiation, there is a perception that NIR is intrinsically less dangerous (because it does notionize), so that the need for legislative control is less compelling. It should be emphasized that all forms of NIR, if present at a sufficiently high intensity, have the capacity to cause serious injury. It is perhaps fortunate that technologies employing NIR have developed in such a way that instances of serious injury are relatively rare and fatality virtually zero. The accepted hazards of most forms of NIR occur within a short time of exposure. The exception to this is ultraviolet radiation (UVR), particularly solar UVR , in which risks of skin cancer and cataract have a stochastic nature and the diseases occur several years after exposure. The perception among sections of the wider community is that all forms of radiation, including NIR, can lead to disease in the long term, despite a lack of consistent evidence. This article reviews the nature of interactions of NIR with biological tissue, explains the rationale behind present‐day exposure limits, and explores some uncertainties that have led to the “Precautionary Principle” being invoked. It also briefly reviews some properties of NIR that have led to its use in diagnosis and therapy.
Pattern Recognition
Authors: Polikar Robi 
Published: April 2006

Abstract
Pattern recognition is concerned with making automated classification, identification, or intelligent decisions about an unknown system or entity, through analysis of data obtained from such entities or systems. This article provides a comprehensive overview for designing a complete pattern recognition system, by explaining individual components that are cascaded to make up the entire system. Each component processes the available data to prepare it for the next component, starting with preprocessing and conditioning the data, extracting relevant features of the data, choosing the most informative features, choosing a classification algorithm to model the data, training the classification system using a suitable learning algorithm, and finally, an evaluation procedure to estimate the true performance of the overall system. Procedures and algorithms that are most commonly used for each step is explained in detail, followed by a survey of more recent and developing areas. Some of the prominent applications of pattern recognition within and outside of biomedical engineering are also provided as a small but representative sample of a vast array of such applications that benefit from pattern recognition.
Microvessel Permeability
Authors: Fu Bingmei M. 
Published: April 2006

AbstractMicrovessel permeability is a quantitative measure of how permeable the microvessel wall is to all kinds of substances including water, solutes, and cells. Important and recent progresses in microvessel permeability and its regulation are presented and discussed. Although microvessel permeability is a classic problem that has been investigated for more than 50 years, the fundamental question related to structure‐function of microvessel walls and properties of cells forming the walls still remains unclear. Employing mathematical models for more accurate interpretations and predictions, new techniques involving fluorescence, atomic force and electron microscopy, and new developments in molecular biology and biochemistry will lead to more fascinating discoveries in this field.
Blood Substitutes
Authors: Sakai Hiromi , Tsuchida Eishun 
Published: April 2006

Abstract
Blood transfusion systems have contributed considerably to human health and welfare. Nevertheless, numerous problems remain, such as infection of hepatitis virus and HIV, blood type mismatching, immunological response, short shelf life, and costs. Blood substitutes have been under development for decades to overcome those problems. Some substitutes for plasma components are already established, such as plasma expanders, electrolytes, and recombinant coagulant factors. Herein, we specifically address the research and development of substitutes for the function of red blood cells (artificial oxygen carriers, or oxygen infusions) such as chemically modified Hbs, encapsulated Hbs, synthetic heme derivatives, and perfluorochemicals. Unexpected side effects hindered further development of the early artificial oxygen carriers and indicated the physiological significance of the structure of red blood cells. Well‐designed and selected artificial oxygen carriers that meet requisite criteria will be eventually realized. They will provide remarkable innovation in conventional medical treatments.
Neural Networks: Applications in Biomedical Engineering
Authors: Najarian Kayvan , Darvish Alireza 
Published: April 2006

Abstract
This paper provides a brief survey of artificial neural networks and their applications. The paper also describes the structure and the training algorithms of some of the most commonly used neural networks and their applications. Neural structures covered in this paper include multilayer sigmoid neural networks, Hopfield networks, radial basis functions, and self‐organizing maps. Finally, some specific applications of neural networks in different fields of biomedical engineering are described.
Respiratory‐Related Evoked Potentials
Authors: Andrew Daubenspeck J. 
Published: April 2006

AbstractRespiratory evoked potentials (RREP s) provide a window into the nature of sensory afferent activity available for respiratory control and the perception of respiratory events. Because RREP s reflect the mass of stimulated activity, the view offered is comprehensive beyond anything possible from individual nerve recordings. Although there are many challenges to the interpretation of RREP s, they offer a unique, noninvasive tool for evaluation of respiratory sensation in intact organisms.
Respiratory Sinus Arrhythmia
Authors: Patwardhan Abhijit 
Published: April 2006

AbstractIt has been long recognized that the period of the heart, that is, the interval between two heartbeats, changes in rhythm with respiration. Change in heart periods that is synchronous with respiration is called respiratory sinus arrhythmia (RSA). In a healthy person, the heart speeds up during inspiration and slows down during expiration. RSA is perhaps one of the more widely investigated phenomenon in the field of integrative physiology. The objective in this chapter is to introduce the reader to RSA, and it is organized to address the following issues: What is RSA? What are the prominent empirical features of RSA? What are the issues related to measurement of RSA? And, what causes RSA? There is considerable evidence that suggests that RSA is a result of autonomic neural activity. Quantified RSA is simple to measure, yet a powerful index that provides an insight about autonomic nervous activity that governs cardiac function. Given the widely hypothesized dominant role of neural function in cardiac health, this index, identified many centuries ago, continues to be the focus of modern scientific exploration.
Risk Management
Authors: Bartoo Grace 
Published: April 2006

Abstract
Biomedical engineers strive to develop devices that are both effective and safe. Risk management is an essential skill that all medical device developers should understand and use aggressively to minimize any potential harm to patients and operators of the device. Risk management is the systematic application of policies, procedures, and practices to the tasks of identifying, analyzing, controlling, and monitoring risks associated with a device. Multiple techniques exist that can be used to conduct risk analyses and estimation such as hazard analysis (HA), failure modes and effects analysis (FMEA), and fault tree analysis (FTA). After risk analyses and evaluation for acceptability is conducted, risk control measures are selected and implemented. These risk control measures should be verified for effectiveness. Analysis of the remaining risk after implementation of the risk control measures should be conducted and the overall acceptability of the residual risk determined. Clearly, the benefits of the device should outweigh the residual risks in order to move forward with the development of the device.
An international standard, ISO 14971:2000, exists that provides a straightforward description of how to establish an effective risk management process. This chapter provides an overview of the risk management process described in that standard and the documentation that is required. Application of risk management throughout the product development process will help the company to anticipate failures, make safer products, and minimize liability exposure.
Sensory Aids
Authors: Seelman Katherine , Brabyn J. , Ortmann A. , Palmer C. 
Published: April 2006

AbstractIndividuals with complete or partial loss of vision or hearing have a reduction of sensory input that affects their interaction with the environment. Approximately 3.5–6 million people have vision loss and 8 million have hearing loss. Different diseases and pathologies give rise to different forms of functional limitations. Individuals with loss of vision or hearing improve function through the use of sensory aids as a supplement to or a substitute for seeing or hearing in order to participate in society and to perform activities of daily living. Sensory aids range from individual medical and assistive devices to technologies that enhance the accessibility of the natural, built, transportation, and information/communications environments. Some individuals with vision loss may also use readers and those with hearing loss may use sign language interpreters to access information. Research and development, commercialization, and public support for purchase of individual aids and change in environmental accessibility have been stimulated or mandated by public laws and regulations such as those related to the Americans with Disabilities Act of 1990. Using a universal design strategy, some aids are designed into mainstream products and environments, as is the case of the decoder chip that produces captioning on the screen of a television set. Universally designed products have spilled over from special interest markets such as deaf and hard of hearing users of captioning to mainstream markets in locations with loud background noise such as health clubs and bars. Although the history of the development of sensory aids is hundreds of years old, opportunities and challenges have proliferated with the development of computing and communications technology. Throughout history, individuals with vision loss and individuals with hearing loss have challenged engineers, and clinicians, and architects with their different medical, functional, and environmental problems.
Simulation Languages
Authors: Roa Laura , Prado Manuel 
Published: April 2006

AbstractA computer simulation model is an abstract entity that describes the dynamics behavior of a target system. It can be designed according to different modeling methodologies and implemented in a computer by means of a programming language. Many specific programming languages have been developed to facilitate this implementation. These are formally designated as modeling languages. The execution of a computer model is referred to as the simulation or experimental phase. Some modern software simulation environments provide extensions to modeling languages that simplify common tasks such as parameter identification, sensitivity analysis, validation, and even the connection to external data sources and other software programs. Accordingly, specific languages used to describe, implement, and even design the subsequent experiments are called modeling and simulation languages or, simply, simulation languages. We use both modeling language and simulation language as synonymous terms throughout the text despite the fact that they are not formally the same.The high number of software environments for modeling and simulation and their dependence on the domain of the system to be modeled makes unsuccessful the review of the state of the art in this field by means of an approach based on the description of their major technical features. This work follows a more fruitful approach, which is the description of the major methodologies and technologies that underlie the simulation languages and software environments. With this objective, the chapter begins with a brief review of the most important milestones in modeling and simulation methodologies, which is followed by a formal description of the current ones. That section is followed by another one devoted to several important mathematical subjects related to language causality, which is the base of some of the major cutting edge advances in modeling languages. Several representative languages and software environments founded on the different methodologies analyzed are cited afterwards. The chapter ends with a section dedicated to review biomedical engineering applications of computer simulation models and current trends in the modeling and simulation field.
Sleep Apnea: Detection and Classification of Infant Patterns
Authors: Sermet Anagun A. 
Published: April 2006

Abstract
Apnea is defined as a period in which an infant stops breathing. When the apnea period is greater than a critical period, serious damage in the infant's brain may result from lack of oxygen. In order to prevent this serious event, a need exists to find a reliable way to detect apnea and to determine causes of apnea. For that reason, sensors exclusively designed for research purposes, and especially manufactured apnea monitors with built‐in sensor, used at homes and pediatrics intensive care units in hospitals have been employed. As a result of the limitations and weaknesses of commercially available apnea monitors, in recent years, artificial intelligence techniques, especially neural networks have gained attention in terms of finding a reliable and alternative way to analyze respiration signals to determine if apnea exists and, if so, the length of apnea. In this study, an overview of apnea, difficulties in apnea monitoring, and elementary information for data acquisition and neural networks are given; a multi‐layered neural network for apnea recognition is designed; and applicability of the designed neural network trained with a set of respiration patterns obtained from infants who have apneic episodes is discussed in terms of detecting and classifying apnea patterns.
Sleep Laboratory
Authors: Penzel Thomas 
Published: April 2006

Abstract
Sleep research has evolved to sleep medicine over the past 20 years. Sleep laboratories are now established in many places in order to diagnose and treat sleep disorders. The most prevalent sleep disorder is insomnia, but this is rarely investigated in a sleep laboratory. Second most prevalent are sleep‐related breathing disorders, with obstructive sleep apnea as the best known disorder. A sleep laboratory provides methods for diagnosing this and other sleep disorders with the use of cardiorespiratory polysomnography. In addition, daytime testing of sleepiness is used to check the effect of treatment on daytime function and performance. Cardiorespiratory polysomnography uses digital equipment with defined requirements on sleep signals, respiratory, movement, and cardiovascular signals. Computer‐based polysomnography tries to support the sleep expert with automated analysis of sleep, respiration, and movement. These methods did not succeed in replacing visual evaluation methods until now. Currently, the definitions for sleep stages are being reassessed. The revised definitions may improve the basis for the development of analysis algorithms, which can then achieve a better validity compared with expert evaluation. In addition, new developments in the field of sensor technology make use of miniaturization and noninvasive signal assessment in order to improve patient sleep comfort during the sleep study.
Stenosis and Thrombosis
Authors: Walsh Peter , McLachlan Craig 
Published: April 2006

AbstractVascular stenosis is defined as a narrowing or constriction to the body or opening of a vessel conduit. Stenosis and thrombus formations are the result of vascular injury and inflammation due to vascular cell dysfunction, resulting in any of the following pathological or healing injury responses: an initial coagulation/thrombus (blood clot) on the vascular inner wall to promote healing or further injury and inflammation; vascular smooth muscle cell proliferation and migration into the blood vessel lumen promoting stenosis following an initial disruption to the endothelium; atherosclerosis in which both early thrombus and smooth muscle cell proliferation and migration participate; and atherothrombosis that interacts with a mature atherosclerotic plaque to form a blood clot on the surface of the plaque resulting in further stenosis or possible emboli. Changes in vascular function are governed by the dynamic mechanical environment consisting of shear stress, wall stresses, and pressure imposed on the cells within the vascular wall as a result of blood flow. Endothelial cells in the intima and the smooth muscle cells within the vessel media are stimulated with these mechanical stresses that alter their behavior. Atherosclerosis and other causes of stenosis develop at localized regions within the vasculature that correlate to localized mechanical conditions. Disease typically occurs at arterial sites where endothelial cells would be exposed to low and oscillatory shear stress. Localized variations in the inner to outer wall stresses also appear to be related to disease‐formation. This chapter reviews studies integrating biology with vascular mechanical events that explain the current theories on stenosis and thrombosis.
Stress
Authors: Debes Jack C. , Wickham Lori L. 
Published: April 2006

Abstract
The word stress has many different meanings depending on the context in which it is used. However, in mechanics, it has a precise meaning. Stress is a measure of force intensity in a material and may be described in terms of a force per unit area. It is important to differentiate stress from strain, which is a measure of the deformation of a material resulting from stress. Stress and strain are separate, but physically coupled entities, which are related mathematically by a constitutive equation.
Temperature Sensors
Authors: Tamura Toshiyo , Tatsuo Togawa 
Published: April 2006

Abstract
Integrated circulatory (IC) sensors are becoming popular to monitor body temperatures. Traditional temperature techniques, such as thermocouples, thermistors, and RDTs are being displaced by silicon sensors with their ease of integration and use. Many traditional sensors types are inherently nonlinear and require signal conditioning to accurately convert temperature into an electrically measurable quantity such as voltage or current. The IC sensors as well as traditional sensors are briefly reviewed.
Thermal Conductivity Measurement of Biomaterials
Authors: Baish James 
Published: April 2006

Abstract

This chapter reviews the theory and practice of measuring the thermal conductivity of biomaterials. Particular attention is given to the special considerations that accompany measurements of soft tissues
in situ
. Many of these techniques are somewhat invasive in their use of small implanted thermistor probes. Others use heat sources and temperature sensors that can operate with only surface contact or with no contact whatsoever. The relative merits of the various techniques are reviewed. The relationship of the intrinsic thermal conductivity to apparent enhancements to the conductivity that develop because of blood perfusion is also presented.