bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrical Impedance Technique for Cryosurgery Monitoring
Authors: Abboud Shimon , Radai Michal M. , Zlochiver Sharon 
Published: April 2006

AbstractMonitoring the extent of the forming ice‐ball, used for destroying cancerous tissue, during cryosurgery procedures is of great importance, especially where the destruction of healthy tissue might cause irreversible functional damage (e.g., in brain cryosurgery). As a result of the extremely high electrical resistivity of a frozen tissue, impedance technique and electrical impedance tomography (EIT) have been suggested as global monitoring and imaging modalities, as a substitute to existing monitoring methods such as magnetic resonance imaging (MRI), computed tomography (CT), or ultrasound (US). In this review, the implications of using the suggested monitoring techniques are discussed, including advantages and limitations with respect to other imaging/monitoring modalities. A concise description of the physical model and mathematical formulation of the forward and inverse problems of EIT is depicted. The results obtained from several theoretical and experimental studies are presented, and the feasibility and prospective issues of impedance technique in cryosurgery is argued.
Biological Database Integration
Authors: Miled Zina Ben , Liu Yang , Li Nianhua , Bukhres Omran 
Published: April 2006

AbstractMany biomedical databases have rapidly become a central part of knowledge discovery in numerous fields including genomics, proteomics, and drug design. These databases are distributed, heterogeneous, and autonomous. This article by presenting a brief overview of some widely used databases to motivate the need for the integration of the distributed biological databases. Supporting this integration faces numerous challenges including various levels of heterogeneity, limited accessibility and redundancy, or conflicts in the data. These challenges are discussed, and different approaches to addressing these issues are presented. The article also includes a comparison among some integration systems that have been proposed for biological databases.
Electrocardiogram (ECG): Automated Diagnosis
Authors: Fotiadis Dimitris , Likas Aristidis , Michalis Lampros , Papaloukas Costas 
Published: April 2006

AbstractElectrocardiogram (ECG) is one of the most common signals used in medical practice because of its noninvasive nature and the information it contains. Its analysis can be used to assess the pathophysiological condition of the heart. Several systems for ECG recording and analysis have been developed for more than a century. Early ECG systems included recording and printing of the signal. Modern systems use computer technology to provide automated diagnosis. The latter is a significant research field and many methods and approaches have been proposed for the detection of ischemia, arrhythmia detection and classification, and diagnosis of chronic myocardial diseases. Those methods are based on the processing of the signal to remove noise and artifacts, extraction of certain features related to diseases, and analysis of the features to obtain the final decision. The analysis is usually based on signal processing, fuzzy logic, and artificial neural networks concepts, mixed with knowledge provided by medical experts. Today, those systems are evaluated using standard databases and must be introduced in clinical practice to be further validated.
Ectopic Activity
Authors: Saiz Javier , Monserrat Marta , Ferrero José María , Gomis-Tena Julio , Chorro Francisco J. 
Published: April 2006

AbstractThe term ectopic activity is used to indicate situations in which the electrical stimulus responsible for the contraction of the heart originates in a zone of the cardiac tissue (ectopic focus) different from the normal one (the sinoatrial node). Two main mechanisms exist that may induce ectopic activity: automaticity (generally subdivided into normal and abnormal) and triggered activity. Ectopic activity caused by normal automaticity appears in cardiac cells in which the automaticity (spontaneous generation of electrical impulses) is an intrinsic property. In normal situations, the potential pacemaker activity in cells different from those in the sinoatrial node is inactive because the spontaneous frequency of impulse generation is higher in the sinoatrial node. However, when the frequency of the sinoatrial node decreases below the spontaneous frequency of a subsidiary pacemaker, this pacemaker takes the control of the heart rate and becomes an ectopic focus. Under several pathological situations, any cell in the heart, even those that normally have no spontaneous activity, could become abnormally automatic. Another mechanism for ectopic activity is known as triggered activity, which consists of an impulse (or a train of impulses) provoked by after‐depolarizations, which are abnormal oscillations of the action potential. Two types of after‐depolarizations exist: early (EADs), which appear during the repolarization phase of action potential, and delayed (DADs), which occur when the repolarization phase of the action potential is completed. The main characteristic of the ectopic activity induced by after‐depolarizations is that a previous electrical impulse is necessary to trigger one or more ectopic beats.
Education
Authors: Demir Semahat 
Published: April 2006

AbstractBiomedical Engineering (BME) education is unique; it is not a traditional education field yet. BME is an interdisciplinary field. BME is the application of engineering and physical sciences into medicine to understand the medical problems and to develop new medical technologies. In detail, BME consists of the basic and clinical applications of biology, chemistry, physics, and mathematics and engineering in medical sciences and life sciences to understand living systems and to provide diagnoses and treatment methods for medical problems.BME education and training opportunities exist in academia, industry, and government. A formal BME education can be obtained in engineering schools or medical schools. The education can be at the undergraduate level (BS), graduate level (MS, PhD, MD), and post‐doctoral level. The degrees granted in BME are Bachelor of Science (BS), Master of Science (MS), PhD, and medical doctor (MD). Some academic programs can offer dual doctorate (MD/PhD) degrees.
Electrical Safety
Authors: Fernández Chimeno Mireya , Riu Pere J. , Silva Martínez Ferran 
Published: April 2006

Abstract
Electrical safety assessment is mandatory for most electrical equipment in almost all countries. For medical devices, electrical safety is regarded in medical safety standards. There is a broad range of medical devices, so the regulations of different countries (European directives, U.S. Food and Drug Administration (FDA) regulations, etc.) provide a classification of medical devices based on the risk. The medical safety assessment depth depends on the equipment class. Many medical devices safety standards in different countries are usually based on the IEC
60601 family standards, so more or less the tests for safety assessment are the same everywhere. In this article, after a brief revision of the effects of electrical current in the human body, we describe the classification of medical devices in Europe (from the medical devices European directives) and in United States (from the FDA). Finally, some IEC 60601 electrical safety topics are explained.
Electrodes
Authors: Aubert André E. , Beckers Frank , Verheyden Bant , van de Voorde Paul 
Published: April 2006

AbstractElectrodes are the interface between an energy source (electrical stimulator) and tissue (place where the stimulus has to be delivered). Electrode technology is a vast and difficult domain; it involves aspects of material science, biocompatibility, design techniques for geometry and implantation, fixation at tissue layers, electro‐chemical reactions, physiology, cardiology, and all other body functions prone to be stimulated. All these aspects are briefly presented in this article. Biocompatibility and materials will be discussed related to electrodes, as this topic is also covered in other articles of this encyclopedia. Basically, electrodes are used externally (applied to the skin) as well as internally. Electrical stimulation is used for many functions. The major applications are in cardiology, for pain relief, for treatment of Parkinson's disease, for treatment of incontinence, and for gastroparesis. Cardiac applications will be highlighted more in this article.Physiological, geometrical, and physical constraints must all be considered by bioengineers and medical doctors, thus leading to optimal sensing, stimulation, adequate thresholds, and long‐term behavior after chronic clinical implantation.
Electrogastrography (EGG)
Authors: Lin Zhiyue , Chen J.D.Z. 
Published: April 2006

Abstract
Electrogastrography (EGG) is a noninvasive technique for the cutaneous recording of gastric myoelectrical activity. Since the first measurement of the electrogastrogram (EGG), a great deal of research has investigated its validation, interpretation, and application. Recently, EGG has received more and more attention. EGG has become an attractive tool to study the electrophysiology of the stomach and pathophysiology of gastric motility disorders. It is currently used in both research settings and clinical settings. The following areas are discussed: the refined methods of EGG, the advanced techniques for processing and analyzing the EGG, and the physiological and clinical applications of EGG.
Event‐Related Potentials
Authors: Bressler Steven L. , Ding Mingzhou 
Published: April 2006

Abstract
It has long been known that the living brains of humans and other mammals generate macroscopic electromagnetic activity that can be recorded from both within and outside the head. From the earliest days of recording this activity, researchers have sought to understand its relation to brain function and to use it to monitor and assess brain state. Continuous records of brain activity, examined without regard to particular points in time, are often useful for determining brain state. However, more detailed knowledge of brain function depends on precise temporal registration of the activity to specific events, either in the external environment or self‐generated. The Event‐Related Potential (ERP) is a temporal signature of macroscopic brain electrical activity related to a sensory, motor, or cognitive event. The Event‐Related Field (ERF) is the magnetic correlate of this activity.
Evolutionary Algorithms
Authors: Repperger Daniel W. 
Published: April 2006

AbstractA brief tutorial on evolutionary algorithms (EAs) is presented. It is demonstrated that such methods are useful for solving certain complex optimization problems and are more general than traditional techniques. There are many possible applications of this procedure within the context of biomedical engineering, and one is presented here with the goal of improving the design of a human–machine interface. The power in this approach is that many different types of variables can be simultaneously optimized, and new solutions develop using the EA methods that may not be found by conventional methods. The objective function to be optimized can be complex when EAs are used, which makes this approach more applicable to systems that occur in nature, which cannot be simply described in terms of linear equations and convex objective functions.
Exercise Hyperpnea
Authors: Ward Susan A. 
Published: April 2006

AbstractControl schemes of ventilationduring moderate exercise [i.e., below the lactate threshold (θL)] have classically incorporated both proportional humoral feedback (carotid and central chemoreflex) and neurogenic feed forward (central command, muscle, cardiocirculatory) to provide stability of arterial PCO2(PaCO2) pH (pHa), and PO2(PaO2). In response to a step work‐rate (WR) forcing from prior rest in the upright posture,increases abruptly for some 15–20 s, this being followed by a subsequent more‐prominent exponential component (consistent with first‐order kinetics). The lack of any sustained error signals in the mean levels of PaCO2, pHa, or PaO2, coupled with the dynamic matching ofwith pulmonary CO2outputbut not O2uptake or WR, suggests that the controller operates as if it incorporates an errorless humoral feedback element proportional to(or some close proxy). In addition, thecontroller seems to evidence considerable redundancy, with particular sensory deficits having little effect on the steady‐stateresponse to exercise or the stability of PaCO2between rest and exercise. AboveθL,kinetics become markedly nonlinear, with steady states being either delayed or not attained, which reflects the influence of the developing metabolic acidemia (1) indirectly, via bicarbonate‐mediated body CO2stores washout, which augments; and (2) directly, to effect respiratory compensation for the falling pHa (this being constrained by the falling PaCO2that results fromincreasing out of proportion to). The carotid bodies are important in mediating this respiratory compensation, although with surprisingly slow kinetics, In conclusion, despite there now being general agreement regarding the overall characteristics of theresponse to exercise, the precise details of the control process(es) remain unresolved.
Exercise Physiology
Authors: Whipp Brian J. 
Published: April 2006

Abstract
Exercise intolerance occurs when a person cannot sustain a required work rate sufficiently long for the successful completion of the task. The ability to sustain an exercise task depends largely on the ability to transport oxygen to its utilization site as the terminal oxidant of the mitochondrial electron transport chain in skeletal muscle, and to clear the resulting metabolically produced carbon dioxide and lactic acid. This process requires the kinetics of the associated ventilatory, pulmonary gas exchange, and cardiovascular system responses to be closely coordinated with the intramuscular requirements for ATP utilization and resynthesis. As the kinetic features of these system responses are highly intensity dependent, any meaningful interpretational frame of reference has to provide a rigorous definition of exercise intensity that takes into account individual differences in the threshold for blood lactate increase relative to maximal aerobic capacity. This article provides an introduction to the fundamentals of normal operation of these systems and their integrated patterns of response to particular stress profiles.
Flow Measurement
Authors: Fontaine Arnold A. , Deutsch Steven , Manning Keefe B. 
Published: April 2006

AbstractFluid flow occurs throughout biomedical engineering ranging from air flow in the lungs to diffusion of nutrients through membranes and involves bothin vivoandin vitromeasurements. Flows involve fluid media in the form of gas, liquid, or multiphase flows of liquids and gas together or in combination with solid matter. They can involve relatively benign flows like that of saline through an intravenous tube to a biochemically active flow of a nonNewtonian fluid such as blood. Many biomedical or bioengineering processes require the quantification of some flow field that may be directly or indirectly related to the process. Such quantification can involve the measurement of volume or mass flow, the static and dynamic pressures, the local velocity of the fluid, the motion (speed and direction) of particles such as cells, the flow‐related shear, or the diffusion of a chemical species.
Cortical Bone Fracture
Authors: Ritchie R.O. , Kinney J.H. , Kruzic J.J. , Nalla R.K. 
Published: April 2006

Abstract

The fracture of bone is a major health concern, particularly among the elderly. It is therefore of importance to understand the mechanics and mechanisms of how bone fails. There have been numerous
in vitro
studies that have evaluated the relevant fracture properties of human cortical bone, but a complete understanding of the actual fracture mechanisms, and more specifically what processes play a role in “toughening” bone, is still lacking. This chapter seeks to provide an overview of the current state of knowledge on the fracture of cortical bone, and to address this issue, when possible, in the context of the relevant microstructural features of bone from a perspective of providing a mechanistic interpretation of how cortical bone fractures. As will be discussed, much of the early work on cortical bone fracture has used fracture mechanics to determine how factors such as age, orientation, location, species, morphology, loading mode, and crack velocity affect the measured single‐value toughness (e.g.,
K
c
or G
c
), determined from the peak load at overload failure. More recently, it has been shown that, akin to many composites or toughened ceramics, the toughness of bone is best described in terms of rising resistance‐curve (R‐curve) behavior, where the evaluated toughness increases with crack extension. Through the use of the R‐curve, the intrinsic and extrinsic factors affecting the toughness are separately addressed from a mechanistic viewpoint, where extrinsic toughening mechanisms are those that act primarily in the wake of a crack, causing rising toughness with crack extension. Furthermore, what little is known about how R‐curve behavior and the associated mechanisms of bone toughening are affected by such factors as age, species, orientation, and location is also presented. Finally, the issue of fatigue failure in cortical bone is addressed in from a mechanistic perspective.
Bioactive Glasses and Glass Ceramics
Authors: Ben-Nissan Besim , Ylänen H.O. 
Published: April 2006

Abstract

Glasses and glass ceramics are widely investigated and produced as biomaterials with CaO and P
2
O
5
additions to their base compositions. One of the main advantages of phosphate‐based materials is their chemical relationship with carbonate hydroxyapatite, one of the main constituents of bone and teeth. Although bioglass was invented in the 1960s, glass has been known to humankind for thousands of years and widely used in building and engineering applications. In this chapter, we review general definitions of glass, glass types presently available, production methods, properties, and their biomedical use. Classification of biomaterials and bioactivity will be introduced to cover the development and progress of the commercially available and currently investigated bioglasses and glass ceramics. Their chemistry, structure, bioactivity, theories behind their bonding within a physiological environment and their interfacial strengths, their synthesis methods, and some of their applications in the biomedical field will be covered.
Bioheat Transfer Model
Authors: Liu Jing 
Published: April 2006

AbstractBioheat transfer models have significant applications in a wide variety of clinical, basic, and environmental sciences. In particular, understanding the heat transfer in biological tissues is a necessity for many therapeutic practices involving either raising or lowering temperature such as cancer hyperthermia, burn injury, brain hypothermia resuscitation, disease diagnostics, thermal comfort analysis, cryosurgery and cryopreservation, and so on. In this section, aiming to provide a fundamental background for theoretically tackling the above bioengineering issues, an overview on the most basic bioheat transfer model, its extended forms as well as typical applications under various high‐ or low‐temperature situations was summarized. Meanwhile, solutions either analytical or numerical to the bioheat transfer model with or without phase change and particularities for choosing the model parameters were illustrated. Some possible extensions of the classic bioheat transfer model were also discussed.
Cardiac Hypertrophy
Authors: Marian Ali J. , Cilingiroglu Mehmet 
Published: April 2006

AbstractCardiac hypertrophy is a common response of the heart to all forms of stress, whether internal, such as a genetic defect in hypertrophic cardiomyopathy (HCM), or external, such as increased afterload in hypertension. It is diagnosed commonly on an electrocardiogram or an echocardiogram showing increased cardiac mass. A diverse array of stimuli could induce cardiac hypertrophy, including physiological stimuli such as exercise, which induces physiological hypertrophy that is beneficial for cardiac function. In contrast, pathological hypertrophy is responsible for diastolic heart failure and is associated with increased morbidity and mortality. Pathogenesis of cardiac hypertrophy entails sensing the stress through transmembrane, nuclear, or cytoplasmic receptors followed by activation of a cascade of signal transducers that ultimately enter the nucleus and activate gene transcription and expression, protein synthesis, cellular organization, and hypertrophy.Genetic factors are important determinants of cardiac hypertrophy. HCM is the prototype of genetic cardiac hypertrophy and is caused by mutations in contractile sarcomeric proteins. It is the most common cause of sudden cardiac death in the young, particularly young competitive athletes, and a major cause of morbidity in elderly. Genetic factors also influence the magnitude of hypertrophic response in acquired cardiac hypertrophy. Clinical studies in humans and experimental studies in animals show that hypertrophy is reversible on removal of the primary stimulus (such as treatment of hypertension or replacement of a stenotic valve) or through blockade of signal mediators that are essential for cardiac hypertrophic response. Regression of cardiac hypertrophy is associated with significant improvement in cardiovascular mortality and morbidity.
Information Retrieval in Biomedical Research
Authors: Miled Zina Ben , Li Nianhua , Mahoui Malika , Bukhres Omran 
Published: April 2006

AbstractInformation retrieval is important in various biomedical research fields. This article covers the theoretical background and the state‐of‐the‐art and future trends in biomedical information retrieval. Techniques for literature searches, genomic information retrieval, and database searches are discussed. Literature searches techniques cover name entity extraction, document indexing, document clustering, and event extraction. Genomic information retrieval techniques are based on sequence alignment algorithms. This article also briefly describes widely used biological databases and discusses the issues related to the information retrieval from these databases. Terminology systems are involved in almost every aspect of information retrieval. The various types of terminology systems and their usage to support information retrieval are reviewed.
Intelligent Patient Monitoring
Authors: Fotiadis Dimitris I. , Likas Aristidis , Protopappas Vasilios 
Published: April 2006

AbstractPatient monitoring encompasses the recording of a patient's physiological data, estimation of a patient's clinical status and progress, as well as the provision of diagnostic and therapeutic recommendations. The incorporation of artificial intelligence aims to assist health‐care professionals in their decision‐making tasks and automate the monitoring process. Those systems are endowed with expert medical knowledge and include biosensors, electrodes, and transducers to measure several biological parameters and interact with medical devices that are often located in different hospital units. Intelligent patient monitoring systems have been primarily developed to assist health professionals in critical care environments, such as the intensive care unit and the operating room. Patient monitoring can be extended to cover patients in out‐hospital environments. Such systems can collect vital signs and communicate with centralized systems equipped with intelligent tools.