bluuebunny/crossref_metadata_2025 huggingface dataset:
Cortical Bone Fracture
Authors: Ritchie R.O. , Kinney J.H. , Kruzic J.J. , Nalla R.K.
Published: April 2006

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

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

Bioheat 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

Cardiac 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

Information 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

Patient 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.
Haptic Interaction in Medical Virtual Environments
Authors: Nikolakis Georgios , Koutsonanos Dimitrios , Moustakas Konstantinos , Daras Petros , Tzovaras Dimitrios , Strintzis Michael G.
Published: April 2006

In recent years, there has been a growing interest in developing force feedback interfaces that allow people to access information presented in 3D virtual reality environments (VEs). One of the major application fields is medicine. Several cases exist where standard medical treatment cannot be applied to patients for several reasons, such as distance from hospital, lack of specialized doctor, and lack of medical equipment. The use of haptic‐enabled virtual environments provides an alternative solution in a variety of such cases, thus enabling assessment and treatment of patients. Furthermore, haptic‐enabled virtual environments provide a nonhazardous means of treatment for several disorders like phobia treatment, where the patient has to be exposed to the phobia object. Training of disabled people, like the visually impaired, is another important application of haptic‐enabled VEs. This chapter presents an extended description of haptic virtual environments and the major methodologies and techniques used in medical applications. Further, it demonstrates indicatively a number of applications in order to illustrate the applicability of VEs in several areas of medical treatment and training.
Biomedical Products, International Standards for
Authors: Marlowe Donald E.
Published: April 2006

International standards for biomedical products have become the coin‐of‐the‐realm in the discussions among governments, product manufacturers, and users. These stakeholders use these documents to allow a supplier and user of goods or services to describe to each other what is being supplied and to ensure or improve public safety and health. What are international standards? This article will discuss the topic at several levels and identify the sources of these standard for biomedical products.
Intestinal Motility
Authors: Garcia-Casado J. , Martinez-de-Juan J.L. , Ponce J.L.
Published: April 2006

Intestinal motility, i.e., gut mechanical activity, is associated with the functions of mixture and transport performed by the small bowel. Its information is of great interest for the diagnosis of such pathologies as intestinal ischemia, irritable bowel syndrome, paralytic ileum, or intestinal obstruction. Nevertheless, the difficult access to this portion of digestive tract and its length and irregular distribution in the abdominal cavity complicate its registration and study.

The measurement of intestinal mechanical activity has traditionally been carried out by manometric techniques. However, physiologic and technical problems derived from the use of these techniques raise doubts about its clinical applications. As there is a myoelectric activity generated by intestinal smooth muscle associated with its mechanical contraction, myoelectric techniques emerge as an alternative solution to the problem of monitoring intestinal motility.

Biomedical engineering proposes different techniques of analysis and registration in response to the necessity of studying these myoelectrical signals. Concretely, spectral analysis and analysis in the time‐frequency domain provide objective parameters to quantify small bowel activity. Even so, registering intestinal myoelectric activity requires surgical intervention for electrodes’ implantation in bowel serosa.

Nowadays, the trend of research studies is directed to the noninvasive measurement of intestinal motor activity by placing sensors on the external abdominal wall: microphones, magnetic flux detectors, or contact electrodes. If technological development of these techniques is achieved, new diagnostic tools of great interest for gastroenterology would be available.
ECG Inverse Problem
Authors: Okamoto Yoshiwo , He Bin
Published: April 2006

We review the inverse problem of electrocardiography. The methods for solving the inverse problems and development in the electrocardiography (ECG) inverse problems are introduced.
Ischemia
Authors: Ferrero José M. , Ferrero Ángel , Trénor Beatriz , Montilla Fulgencio , Saiz Javier , Rodríguez Blanca
Published: April 2006

The word “ischemia” refers to a situation in which the blood flow is insufficient to meet the metabolic demands of a tissue or an organ. Ischemia is caused by the total or partial occlusion of an artery. It can create a life‐threatening situation, and the vascular diseases related to ischemia are among the first causes of mortality and morbidity in the world. In its acute form, ischemia is usually originated by the rupture of a vulnerable atherosclerotic plaque, by the lodge of an embolus in an artery, or less frequently, by an artery spasm. On the contrary, chronic ischemia is related to stable atherosclerotic plaques that narrow the artery lumen.

Ischemia can affect different organs or tissues, but its most harmful (and frequent) forms are myocardial and cerebral ischemia. Limb, mesenteric, and renal ischemia are also clinically significant. Different techniques are used to diagnose ischemia, including analysis of bioelectric signals (electrocardiogram), ultrasonic techniques (ultrasonography and doppler‐echography), angiography, magnetic resonance imaging (MRI ), or computerized axial tomography (CAT scan). In the treatment of ischemia, percutaneous interventions (angioplasty), together with stent placement, are used in addition to surgery and pharmacological therapies.

Acute myocardial ischemia is a life‐threatening form of ischemia. It causes different metabolic alterations that lead to changes in ionic concentrations, action potentials, and overall electrical activity of the heart, setting the stage for malignant arrhythmias to occur (e.g., ventricular fibrillation) and posing a critical threat on the life of the patient.
Intelligent Mobility Aids
Authors: Simpson Richard C. , Rentschler Andrew
Published: April 2006

Independent mobility is a critical component of a person's quality of life. Although many persons with mobility impairments can be accommodated by traditional mobility aids (e.g., canes, wheelchairs, scooters, and walkers), a segment of the disabled community exists who find it difficult or impossible to use traditional mobility aids independently. This population includes, but is not limited to, persons with low vision, visual field neglect, spasticity, tremors, and cognitive deficits. To accommodate this population, researchers have used technologies originally developed for mobile robots to create intelligent mobility aids. These devices typically consist of either a traditional mobility aid to which a computer and a collection of sensors have been added or a mobile robot base to which a seat and/or handlebars have been attached. In this article, we summarize research that has been conducted to date on intelligent mobility aids based on power wheelchairs and wheeled walkers (i.e., rollators).
Multiphoton Microscopy
Authors: Diaspro Alberto , Caorsi Valentina , Bianchini Paolo , Chirico Giuseppe , Usai Cesare
Published: April 2006

Nowadays, optical microscopy has evolved into three‐dimensional (3‐D) (x‐y‐z) and four‐dimensional (4‐D) (x‐y‐z‐t) analyses allowing researchers to probe even deeper into the intricate mechanisms of living systems. Within this scenario, two‐photon and multiphoton excitation (TPE, MPE) microscopy are probably the most relevant advancement in fluorescence optical microscopy since the introduction of confocal imaging in the 1980s. MPE microscopy has a 3‐D intrinsic ability coupled with almost five other interesting capabilities, namely: (1) MPE greatly reduces photo‐interactions and allows imaging of living specimens on long time periods; (2) MPE operates in a high‐sensitivity background‐free acquisition scheme; (3) MPE microscopy can image turbid and thick specimens down to a depth of a few hundred micrometers; (4) MPE allows simultaneous excitation of different fluorescent molecules reducing colocalization errors; and (5) MPE can be used to prime photochemical reactions within a subfemtoliter volume inside solutions, cells, and tissues. Besides, MPE fluorescence microscopy is not only revolutionary in its ability to provide the above‐mentioned features, together with other practical advantages, but also in its elegance and effectiveness of application of quantum physics. The MPE story, more specifically TPE, dates back to 1931, and its roots are in the theory originally developed by Maria Göppert‐Mayer that brought, passing through the scanning nonlinear microscope developed by Colin Sheppard in Oxford at the end of the 1970s, to the revolutionary and successful results on biological samples obtained at the Watt Webb laboratories by Winfried Denk and colleagues at the beginning of the 1990s. MPE can be considered a young microscopical technique. In general, it is more convenient to consider TPE, for the sake of simplicity.
Muscle, Skeletal
Authors: Felici Francesco , Sbriccoli Paola
Published: April 2006

Skeletal muscle is the actuator of motor programs generated by the central nervous system (CNS). The CNS fine‐tuning of muscles’ activity makes very complex motor patterns appear extremely simple and smooth. This chapter will provide a synthetic summary of the most up‐to‐date knowledge in the field of muscle contractile properties and the relationships between muscle structure and function. To date, despite the large amount of information concerning muscle structure and function, the equations describing muscle mechanical behavior are yet to be fully defined, which can be largely attributed to the fact that the real muscle exerts its action along with other mechanical structures. Muscle forces must be transmitted to bones through the muscle‐tendon junction and the tendon. The mechanical properties of such elements may influence muscle force exertion and its mechanics, thus the necessity for developing models of muscle mechanics that are continuously updated with new results provided by the experiments. However, to respect the boundaries of this section, we will not refer either to CNS control of muscle activity or to the mechanical properties of noncontractile elements. Also, the energetic aspects of muscle contraction will not be discussed in this chapter.
Oculomotor Control
Authors: Hung George K.
Published: April 2006

The main aim of oculomotor control is to drive the eyes in a rapid, stable, and coordinated fashion to provide accurate bifixation of targets in space. Eye movement measurements have provided quantitative assessments of these control processes. Indeed, advances in eye movement measurement technology and cortical imaging techniques will continue to provide deeper insights into neurological processes that guide oculomotor responses under both normal and disease conditions.
Optoelectronics
Authors: Stroscio Michael A. , Dutta Mitra
Published: April 2006

Optoelectronics embodies a broad range of scientific and technological knowledge and enables the design and application of devices with both optical and electronic inputs and outputs. Accordingly, optoelectronic devices operate in a greater variety of modes and are more functional than their purely electronic counterparts. This rich variety of operational modes has had an enormous positive influence on lightwave communication systems, on devices for light‐to‐electric energy conversion, and on optoelectronics‐based switching and logic elements. These devices also underlie many innovations such as bar‐code pricing, laser printers, laser readers, etc. Optoelectronic devices have unique abilities to monitor the amplitudes and temporal characteristics of radiation in the ultraviolet (UV), visible, and infrared (IR) regions of the electromagnetic spectrum. Moreover, optoelectronic devices are capable of producing radiation spanning the UV, visible, and IR spectra at ever‐increasing power levels and with temporal characteristics that may be controlled with sub‐nanosecond precision. These novel capabilities and expanded levels of functionality will continue to open many avenues for biomedical applications, thereby expanding the list of current applications such as laser surgery. In many cases, the optical properties of these devices are determined by the electronic properties of the materials used in the construction of the active components of an optoelectronic device or system. Optoelectronic devices span the range from simple devices, such as a detector of light based on the photoelectric effect discovered by Albert Einstein (1879–1955) in 1905, to modern monolithically integrated semiconductor heterostructure devices incorporating miniature lasers, photodiodes, and electronic components, such as amplifiers, all grown on the same semiconductor substrate. These devices generally function for the purpose of or by employing techniques for the processing of optical and electronic signals. The variety of optoelectronic devices has increased enormously in the last few decades because of advances in the materials science underlying the growth, fabrication, and production of components for optoelectronic devices and systems. The rich and growing diversity of optoelectronic devices is making possible continuously expanding applications of optoelectronics in biomedical engineering.
Nanoparticles in Biomedical Photonics
Authors: Chithrani B. Devika , Chan Warren C. W.
Published: April 2006

Photonics refers to the studies or applications of light or photons, which includes the study and design of lasers, the applications of fluorophores in diagnostics, or the use of light‐scattering technologies. Photonics is a broad research field. In this chapter, we will focus on an emerging subdiscipline of photonics, which is the development of gold nanostructures for biomedical applications. Gold nanostructures are of interest to the photonics community because these materials have interesting tunable optical properties. Biomedical engineers are exploiting these properties for development of new diagnostics, drug delivery, and therapeutics.
Piezoelectric Devices in Biomedical Applications
Authors: Lewin Peter A. , Reid John M.
Published: April 2006

We focus on piezoelectric devices in biomedical applications only. The devices are classified depending on their electrical, mechanical, or hybrid output signal. The hybrid device operates in a reversible mode and can generate both electrical and mechanical signals at its terminals. Electrical output piezoelectric sensors include frequency generators, force and pressure measurement sensors, accelerometers, velocity and displacement sensors, and receivers such as microphones. Linear scanning motors and acoustic wave generators fall into the category of mechanical output devices or actuators. Also, acoustic wave generators, such as lithotripters, loudspeakers, and ultrasonic therapy applicators, can be considered as actuators. Medical ultrasonic transducers used to generate images of internal organs of the body can be defined as hybrid or combination devices, as they act as both actuators and receivers producing an electrical signal proportional to the input mechanical stimulus at their terminals, and conversely, a mechanical displacement amplitude proportional to the electrical excitation.
Proteomics
Authors: Alterovitz Gil , Afkhami Ehsan , Barillari Joseph , Ramoni Marco
Published: April 2006

Research in proteomics involves studying the structure, expression, localization, interactions, and cellular roles of all proteins within a particular organism or subcomponent thereof. Researchers coined the term “proteomics” in the early 1990s to describe a new approach to studying proteins, focusing on high‐throughput analyses and on breadth rather than depth. Proteomics researchers aim to use experimental techniques that trade accuracy for volume in order to build up a complete picture of the function of large groups of proteins. Key research in the field focuses on the development of new high‐throughput techniques and the computational machinery needed to analyze the data those techniques produce.
Pulmonary Mechanics
Authors: Bates Jason H.T.
Published: April 2006

Pulmonary mechanics deals with relationships among gas pressures, flows, and volumes in the lung. Assessing pulmonary mechanics is important for diagnosing lung disease and for following the progress of therapy. Clinical assessment of lung function is usually based on empirical quantities derived from recordings of forceably exhaled volume, and from measurements made in the body plethysmograph. In the research laboratory, pulmonary mechanics are frequently assessed with system identification techniques to determine quantities such as input impedance. These quantities are interpreted using physiologically based mathematical models.
Pulmonary Medicine, Applications of Biomedical Engineering to
Authors: Cherniack Neil S. , Longobardo Guy S.
Published: April 2006

Pulmonary medicine is concerned with preventing and treating diseases that affect the lungs as well as the entire respiratory system, i.e., the muscles that create the pressures needed to bring air into and out of the lungs, as well as the sensors and the respiratory neurons that set the level and pattern of breathing. The respiratory system provides oxygen for body metabolic needs and rapidly removes in the form of carbon dioxide the acids produced as a result of metabolic processes. It is functionally and structurally linked to other systems such as the cardiovascular and renal system, which also act to maintain tissue oxygenation and acid–base balance.

The lung is the primary interface of the respiratory system with the outside world, and because breathing involves the daily exchange of almost 7500 L of air containing microorganisms and injurious particles, the lung is the part of the respiratory system most commonly affected by disease. However, disease can affect any part of the respiratory system. Unchecked, some respiratory diseases lead to respiratory failure characterized by hypoxia and elevated levels of carbon dioxide. In addition, intermittent hypoxia and hypercapnia can occur during sleep as a consequence of episodic upper airway obstruction.

Bioengineering applies the basic scientific approaches of biology, physics, chemistry, and engineering to the medicine of the respiratory system to develop mathematical models, which describe and explain pathophysiological processes and develop instruments and diagnostic processes to treat or support the respiratory system.
Ultrasonic Imaging
Authors: Insana Michael F.
Published: April 2006

The basic principles of ultrasonic B‐mode imaging are summarized. Tissue features that generate contrast and system features that control image quality are reviewed in the context of breast cancer imaging. Approaches to signal modeling, including B‐mode and Doppler techniques, are reviewed to guide methodological design and clinical evaluation. The article concludes with a brief summary of current research.
Ultrasonic Transducers for Medical Imaging
Authors: Lockwood Geoffery R.
Published: April 2006

The performance of modern ultrasound imaging systems is primarily determined by the characteristics of the ultrasound transducer. Early imaging systems were based on single‐element transducers. These transducers had a fixed focal distance and had to be mechanically scanned to create an image. The systems were cumbersome to use, and the image quality was relatively poor. Much of the success of modern ultrasound imaging can be attributed to the development of efficient transducer arrays. The ultrasound beam produced by an array can be electronically steered and focused. Electronic steering avoids the need to mechanically scan the transducer, whereas electronic focusing provides improved resolution over a large imaging depth. Since transducer arrays were first introduced in the late 1970s, there has been a steady improvement in the efficiency and resolution of arrays. Transducer arrays are now available in a variety of geometries and operating frequencies, each optimized for a particular imaging application. As new transducer materials and improved fabrication techniques have become available, there has been a corresponding improvement in the quality of the ultrasound images. The pace of this development has not slowed, and improvements in ultrasound imaging can be expected for many years to come.
Viscoelasticity
Authors: Bilston Lynne E.
Published: April 2006

Viscoelastic materials, which combine viscous and elastic characteristics, are abundant in the body. The theory of viscoelasticity is widely used to describe their response to mechanical loading, for both physiological and injurious levels of loading. Most viscoelastic materials are nonlinearly viscoelastic for strains of practical interest. This requires the use of nonlinear viscoelastic theories, of which quasi‐linear viscoelasticity is the most common. Structural viscoelastic models, which attempt to replicate the multiphase structure of soft biological tissues, have also been developed and are increasing in flexibility and complexity to better match the observed mechanical behavior of soft tissues. Future challenges in viscoelastic modeling of human body tissues include determiningin vivoproperties and developing computationally efficient models that can still capture the complex nonlinear viscoelastic behavior of these tissues.
Wide Area Networks
Authors: Yao Wenbing , Loo Kok-Keong
Published: April 2006

In this chapter, a general introduction to wide area networks (WANs) and the relevant popular WAN technologies are given. The definition of WAN, the development of WAN technologies, the international organizations that have important impact on the development of WAN technologies, and the classification of WANs are introduced. The broad‐band access technologies for WAN, including the xDSL and Cable Modem, are summarized. ISDN as a typical example of circuit‐switched WAN is also briefly explained. In the last section, the WAN transport technologies section, three key technologies, X.25, frame relay, and ATM, are discussed.
Magnetic Resonance Current Density Imaging
Authors: Eyüboğlu B. Murat
Published: April 2006

Magnetic resonance current density imaging (MRCDI) is an emerging modality that is used to image current density distribution created by an externally applied current to a conductor that contains nuclear magnetic resonance (NMR) active nuclei. Distribution of externally applied electrical current inside the body provides important information in many biomedical engineering applications: such as improvement of electrical stimulation devices by optimal electrode designs for electrosurgery, defibrillation, and cardiac pacing; optimization of defibrillation efficacy; determination of electrode geometry and current level in cancer treatment; electroconvulsive therapy; and noninvasive localization of epileptic spikes in the brain and determination of fatal current levels. Knowledge of current density distribution originating from a pair of electrodes can be used to calculate lead‐sensitivity maps of biopotential recording electrodes, and to improve the sensivity matrix used in electrical impedance tomography (EIT) image reconstruction. Finally, accurate measurement of current density distribution leads to high‐resolution conductivity imaging.
Telemedicine: Ubiquitous Patient Care
Authors: del Pozo Francisco , Hernando M. Elena , Gómez Enrique J.
Published: April 2006

After a brief introduction to telemedicine, the target scenarios of ubiquitous patient care are described, by means of several examples, depicting their principal requirements and outlining the generic conditions that modern telemedicine systems have to assure: First, the provision of an efficient cooperative working space to coordinate all professionals of the multidisciplinary care team; and second, a multi‐access environment to optimize connectivity. The technology required to implement ubiquitous care services is introduced to show the principal ingredients of telemedicine system to serve as an initial guide to any one interested in the installation of them. Finally the critical issues on which it depends, in our view, the success and sustainability of any implementation of these telemedicine services are reviewed, namely: the security issues, the intelligent handling of information, and the interoperability of the telemedicine products. A final thought on the future of these services closes the article.
Telemedicine: Teleconsultation Between Medical Professionals
Authors: del Pozo Francisco , Gómez Enrique J. , Elena Hernando M.
Published: April 2006

This article presents a general view of the teleconsultation technology and services to support the cooperative work between professionals to extend the capillarity of the knowledge resources within the health‐care system. Teleconsultation systems are here envisaged as a way to extend the offer of specialized care services closer to the points of care, and to provide health‐care professionals remote access to the images and other supporting information captured at their points, to elaborate the appropriate diagnosis or advice. The different scenarios that we could encounter under this category of telemedicine services are followed by a description of the technology required to instrument them, with special emphasis on those aspects that impact most on their operation performances. It is concluded with the identification of the critical issues that, in our experience, condition the success of any teleconsultation installation.
Carbyne‐Containing Surface Coatings
Authors: Demyashev Gregory M. , Taube Alexander L.
Published: April 2006

Synthesis of carbyne‐containing surface coatings for a variety of biomedical applications is a matter of a great importance. Carbynes with a one‐dimensional chain‐like molecular structure that were discovered a few decades ago represent a basic allotropic form of carbon equally with diamond and graphite. Carbynes appear as quasi‐crystalline structures of carbon‐chains with double (CC)nand alternating single/triple (–CC–)ncovalent bonds. The aim of this article is to summarize existing information about carbyne‐containing surface coatings for biomedical applications and to outline novel approaches for synthesis of such functional biomaterials in the form of coatings.

The first research and development of carbyne‐containing materials demonstrated their great potential for biomedical applications. Carbynes possess a high biocompatibility, low litho‐ and thrombogenic activity, high resistance to chemically aggressive biological liquids, antibacterial and antifungal activities, and so on.

Equally with the state‐of‐the‐art biomaterials in question, three novel carbyne‐containing surface coatings are here highlighted: (1) carbynes‐W3C composite coatings chemically vapor‐deposited, (2) carbyne‐containing layers formed by electropolishing of the surface of transition metal carbides, and (3) microwave‐induced defluorination of polytetrafluoroethylene (PTFE or Teflon) on the interface of “PTFE‐Water” at ∼95°C.

This article demonstrates opportunities to synthesize the carbyne‐containing surface coatings that can be practically realized for biomedical applications. The three coating processes afford the opportunity to modify the surfaces of the basic artificial implants; i.e., metallic/ceramic artificial implants can be coated by the Carbynes‐W3C composite; artificial implants manufactured from transition metal alloys can be electrochemically modified by carbyne‐containing coating; and PTFE‐implants can be modified by microwave‐induced surface defluorination leading to the formation of a carbyne‐containing surface layer.
Cell Patterning
Authors: Filipponi Luisa , Nicolau Dan
Published: April 2006

Cell patterning comprises a set of techniques used to create organized spatial cellular patterns on surfaces. The selectivity of cell attachment is most commonly controlled by using classic and new microfabrication technologies, such as photolithography and soft‐lithography, respectively, to create microscale patterns having cell adhesion‐specific chemistry and topography. Different surfaces, such as patterns of polymers, proteins, and adhesive‐promoting peptides, have been used as well as different planar and profiled geometries. It is also possible to deposit cells directly on surfaces through various “direct write” approaches. The increasing need to produce patterns of cells havingin vivo‐like functionalities is motivating attempts to build three‐dimensional cellular patterns where the interaction of cells with the surrounding environment, including other cells, can be precisely and predictably controlled with micro‐ and even nano‐scale precision.
Recurrence Quantification Analysis
Authors: Zbilut Joseph P. , Webber Charles L.
Published: April 2006

The complexity, nonlinearity, and nonstationarity of biological time series typically defy quantitative description. Living systems are governed by numerous, continuously changing, interacting variables in the presence of noise. Such conditions often challenge traditional methods such as Fourier transforms. An approach for assessing such nondeterministic complexity is recurrence quantification analysis (RQA). Strategies implementing quantification of recurrences have often been successful in diagnosing changes in nonstationary signals not easily detected by traditional methods.
Bioactive Bone Cements
Authors: Fernández Enrique
Published: April 2006

This chapter overviews the main scientific and technological aspects that have influenced the evolution of bioactive bone cements since its discovery around 1983 until the present time. Thermodynamic and kinetic aspects have been highlighted. The information is presented in such a way that any reader will understand the steps to formulate and characterize novel bioactive bone cements.
Electromyography (EMG), Electrodes and Equipment for
Authors: Pozzo Marco
Published: April 2006

The mechanical activity of skeletal muscles is associated with the generation of electric signals that can be recorded by electrodes inserted in the muscle or fixed over the skin. The electric signals generated by the muscles during their activity are referred to aselectromyographic(EMG) signals.

Intramuscular EMG recordings were the first techniques developed to study the physiology of muscle control and force generation, and are still widely used in research, as well as in clinical practice, to reveal pathologies of neurogenic or myogenic origin. In recent years, however, a remarkable effort has been put in the development of novel surface EMG recordings system and techniques to complement and integrate the fields of application of intramuscular EMG ones. The information that can be extracted from EMG signals is now widely used for research purposes and in many different sectors including rehabilitation medicine, ergonomics, neurophysiology, and sports and space medicine.

This chapter will provide a short overview of the state of the art in the design of intramuscular and surface EMG electrodes and equipment, as well as a brief synopsis on their clinical and research applications.
Dentin–Enamel Junction of Human Teeth
Authors: Walker Mary P. , Fricke Brian
Published: April 2006

The Dentin–enamel junction (DEJ) is a natural junction that unites two mechanically dissimilar calcified tissues: hard, brittle enamel and the subjacent softer, tougher dentin. The DEJ structure, an effective obstacle for enamel‐initiated crack propagation, is generally described as a series of 25–100‐μm‐diameter scallops with their convexities directed toward the dentin. In addition, microscallops seem to be housed within each scallop and a finer nanolevel structure within each microscallop. The DEJ is also characterized by parallel 80–120‐nm‐diameter collagen fibrils that merge with the interwoven fibrillar network of the dentin collagen matrix and directly insert into the enamel mineral. The fibrils, however, extend only a few hundred nanometers into the enamel.
Computer Assisted Radiology (CAR)
Authors: Tourassi Georgia D.
Published: April 2006

Radiology has experienced radical advancement in a very short time since its inception a little more than a century ago. What is really impressive is that most of this advancement has taken place since the advent of computers in medical imaging. Computers marked the beginning of the digital era for radiology in the 1960s. Since then conventional film/screen x‐ray imaging has been overshadowed by a plethora of digital medical imaging modalities that entered the clinical arena. In addition, the rapidly increasing availability and efficiency of computer technology have completely transformed all aspects of clinical radiology beyond image acquisition. Nowadays, computers are the cornerstone of technological innovations related to image display and interpretation, communication of imaging results, and clinical practice workflow in radiology. The termcomputer‐assisted radiology(CAR) has been adopted to denote the clinical integration of computers and information technology to provide an environment of support to radiologists during the diagnostic interpretation of medical images.
Electronic Health Record
Authors: Katehakis Dimitrios G. , Tsiknakis Manolis
Published: April 2006

The term electronic health record (EHR) refers to the complete set of information that resides in electronic form and is related to the past, present, and future health status or health care provided to a subject of care. The primary purpose of electronic health records (EHRs) is the documentation, retrieval, transmission, linking, and processing of multimedia information to legitimate users for the delivery of knowledge and decision support that enhance efficient and secure health‐related services, regardless of the health‐care model applied. Secondary uses of EHRs are related to policy development, education, research, quality management, and disease surveillance via anonymized datasets requiring, in most of the cases, explicit consent on behalf of the subject of care.
Epithelial Pre‐cancers and Cancers, Optical Technologies for Detection and Diagnosis of
Authors: Carlson Alicia L. , Richards-Kortum Rebecca
Published: April 2006

In this article, the authors focus on optical technologies that have the potential to dramatically improve the detection and classification of epithelial precancers and cancers. Epithelial precancers are associated with a variety of morphologic and molecular changes, which currently can only be assessed through invasive, painful biopsy and subsequent histologic analysis. In addition to visual inspection and histology, a growing number of optical techniques are being applied to the detection of precancerous changesin vivowithout the need for biopsy, and may serve as diagnostic tools in the future as diagnostic algorithms are further developed. Optical technologies are ideally suited to detect cancer‐related changes because they can noninvasively detect biochemical and morphologic changes with subcellular resolution throughout the entire epithelial thickness. With optical technologies, diagnosis can be achieved in real time using automated techniques.

This article reviews recent developments in reflectance and fluorescence spectroscopy, reflectance and fluorescence confocal microscopy, optical coherence tomography, and optical coherence microscopy. For each emerging technology, the basic principles and the current and potential applications in early cancer detection and diagnosis are reviewed. The potential of optical molecular imaging using exogenous contrast agents to enhance molecular features within tissue that are important for precancer and cancer diagnosis are also reviewed. Finally, future improvements needed to advance optical technologies into widespread clinical use for precancer detection and diagnostic classification are outlined.
Foreign Body Reaction
Authors: Voskerician Gabriela , Anderson James M.
Published: April 2006

The foreign body reaction composed of macrophages and foreign body giant cells is the end‐stage response of the inflammatory and wound healing responses following implantation of a medical device. An overview of events leading to the foreign body reaction is presented. These events include protein adsorption, monocyte adhesion, macrophage adhesion and activation, macrophage fusion and foreign body giant cell formation, and fibrous capsule formation. Biomaterial surface properties play an important role in modulating the foreign body reaction in the first two to three weeks following implantation of a medical device even though the foreign body reaction at the tissue/material interface is present for thein vivolifetime of the medical device.
Heart Valve Tissue Engineering
Authors: Vesely Ivan
Published: April 2006

Valvular heart disease is a slow, debilitating process during which the cardiac valves become stenosed or incompetent and cease to aid in the delivery of blood. Unless the diseased valve is repaired, or replaced with a bioprosthetic or mechanical artificial valve, the patient eventually dies from cardiopulmonary failure. Implanting artificial heart valves involves cutting the chest open, placing the patient on cardiopulmonary bypass, and sewing the prosthetic valve into the aorta. Although the mitral valve also becomes diseased, repair of the mitral valve is now much more common than replacement.
Xenotransplantation
Authors: Ogle Brenda M. , Platt Jeffrey L.
Published: April 2006

Xenotransplantation refers to the transplantation of cells, tissues, or organs between individuals of different species. It was proposed nearly a century ago as a way to replace the function of failing human organs, because it then was not clear how human organs could be obtained for that purpose. Xenotransplantation is hindered by severe immunological responses leading to rejection and, because of these responses, successful application in people has not been achieved. A severe shortage of human organs and recent advances in genetic engineering of large animals that might address the immunological problems have sparked interest in xenotransplantation. If these problems were addressed, xenotransplantation could allow a vastly expanded application of transplantation for the treatment of disease. However, new concerns about transmission of infection between species has dampened enthusiasm for clinical application of xenotransplantation.
Magnetic‐Field‐Induced Phase‐Selective Synthesis of Ferrosulfide Microrods by a Hydrothermal Process: Microstructure Control and Magnetic Properties
Authors: He Z. , Yu S.‐H. , Zhou X. , Li X. , Qu J.
Published: April 2006

Microrods of the ferrosulfide minerals greigite (Fe3S4) and marcasite (FeS2) are selectively synthesized by an in situ magnetic‐field‐assisted hydrothermal route. Each complex microrod is composed of fine building blocks with different shapes. The unique magnetic properties of the microrods and electrical performance of a single microrod are studied. The results demonstrate that the magnetic properties of the ferrosulfide minerals are strongly related to their corresponding microstructures. The value of the low‐temperature transition increases as the greigite component in the product decreases. The combination of small‐molecule sulfur precursors and an applied magnetic field makes possible the selective synthesis of ferrosulfide minerals with different phases and distinct microstructures, underlining the fact that the magnetic field can be a useful tool as well as an independent parameter for the phase‐selective synthesis and self‐assembly of inorganic building blocks in solution chemistry.