bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biomaterials, Testing and Structural Properties of
Authors: Shi Donglu , Wen Xuejun 
Published: April 2006

Abstract

Previous studies have shown that the porous hydroxyapatite (HA) is bioactive and can be and used as a bone substitute in hard tissue prosthetics. However, the weak mechanical properties of HA are the primary obstacles to its applications. One approach to have a bone substitute with both required mechanical strength and bioactivity would be improve the bioactivity of some strong substrates. To this end, two major deposition methods, suspension method, and thermal deposition method, were employed in this work in which HA was uniformly coated onto the surfaces of highly porous and strong substrate of alumina. In suspension method, finely ground HA powders were mixed in an organic solvent and a binder to form suspension for coatings. In the thermal decomposition method, calcium 2‐ethyl hexanoate and bis(2‐ethyhexyl) phosphite were used as starting materials. Both techniques have proved to be effective in forming an adherent coating of HA onto a porous alumina substrate. The adherent strength of the HA coating is satisfactory for bone replacements. The thermal decomposition method, in comparison to the HA–glass suspension technique, eliminates all glasses (as sintering aids) that are not bioactive. Mechanical properties, interfacial adhesion behaviors, structural properties, and bioactive behaviors are studied using mechanical testing, scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential thermal analysis (DTA). The coated HA layer bonds strongly to the substrate through interface diffusion, and the layer is microstructurally and chemically uniform on the surfaces of the interconnected pores in the matrix of the substrate. The mechanical property testing results demonstrate that porous substrates with HA coating are much stronger than porous substrate made of pure HA. The compressive strength of the HA composite reaches 10 MPa, a value 10 times higher than that of porous HA. The
in vitro
bioactivity of HA coating on promoting the calcium phosphate deposition was affected by both structural crystallinity and specific surface area. High temperature sintering inevitably changes the crystallinity of the coated HA, and in turn affects its bioactivity. Well‐crystallized HA that is heat treated at high temperatures has resulted in a reduced bioactivity. The bio reaction rate was found to increase with the surface area of HA. The stability of the well crystallized HA is associated with the high driving force required for the formation of hydroxy‐carbonate apatite (HCA) phase. These results indicate a high potential for structural bone substitutes in the hard tissue prosthetics.
Biomaterials: Tissue Engineering and Scaffolds
Authors: Khang Gilson , Lee Sang Jin , Kim Moon Suk , Lee Hai Bang 
Published: April 2006

AbstractTissue engineering offers an alternative to whole organ and tissue transplantation for diseased, failed, or abnormally functioning organs. Tissue engineering requires a triad of components: (1) Harvested and dissociatedcellsfrom the donor tissue; (2)scaffoldsmade of biomaterials on which cells are attached and cultured, then implanted at the desired site in functioning tissue; and (3)growthfactorsthat promote and/or prevent cell adhesion, proliferation, migration, and differentiation by up‐regulating or down‐regulating the synthesis of protein, growth factors, and receptors.Of these three key components, scaffolds be play a critical role. Scaffolds direct the growthof cells seeded within the porous structure of the scaffold, orof cells migrating from the surrounding tissue, to eventually mimick a natural extracellular matrix. In this section, a review is given of the biomaterials and procedures used in the development of tissue‐engineered scaffolds, including: (1) natural and synthetic, polymeric biomaterials (2) bioceramic scaffolds, (3) cytokine‐released scaffolds, (4) the fabrication and characterization of scaffolds, (5) surface modifications, and (6) scaffold sterilization. However, to approach a more natural three‐dimensional environment necessary for successful organ and tissue transplantation, the combined efforts of researchers from the fields of biology, biochemistry, and material science/engineering will be needed to further develop scaffolds that will support biological signals for tissue growth and reorganization.
Biomechanics of Exercise Fitness
Authors: Ariel Gideon 
Published: April 2006

AbstractThe main purpose of this article is to focus on the biomechanical principles of movement, the scientific bases of training and fitness, and the optimization of human performance at any age. These are not just nonsense concepts added to the quantities of known theories, but are objectively quantifiable procedures that encompass our understandings and can produce precise conclusions. Mathematical principles and gravitational formulations provide the cornerstones for optimizing human performance. Biological, anatomical, physiological, and medical discoveries are always under investigation, challenge, and improvement and these findings will be incorporated into many of the current theories.
Blood Collection and Processing
Authors: Terry Teresa M. , Cox Josephine H. 
Published: April 2006

Abstract
Access to affordable, quality healthcare is considered one of the basic rights of human beings. By ensuring that the benefits of modern medicine are available to all, we can prevent people from dying prematurely, increase productivity, and health of everyone. Blood is one of the most easily accessible sources of body fluids that can provide information on health status and changes induced as a result of drug, vaccine, or other therapeutic interventions. This article describes the general procedures for drawing and processing of blood for screening, analysis, and diagnostic purposes.

The life blood streaming thro’ my heart, Or my more dear immortal part, Is not more fondly dear. John Bunyan, Pilgrim’s Progress.
Blood Gas Measurements
Authors: Elsharydah Ahmad , Cork Randall C. 
Published: April 2006

AbstractBlood gas measurement‐monitoring is essential to monitor gas exchange in critically ill patients in the intensive care units, and “standard of care” monitoring to deliver general anesthesia. It is a cornerstone in the diagnosis and management of the patient's oxygenation and acid‐base disorders. Moreover, it may indicate the onset or culmination of cardiopulmonary problems, and may help in evaluating the effectiveness of the applied therapy. Numerous studies and reports have shown the significance of utilizing blood gas analyses in preventing serious oxygenation and acid‐base problems. This article gives a summarized explanation of the common methods and instruments used nowadays in blood gas measurements in clinical medicine. This explanation includes a brief history of the development of these methods and instruments, the principles of their operation, a general description of their designs, and some of their clinical uses, hazards, risks, limitations, and finally the direction in the future to improve these instruments or to invent new ones.
Blood Pressure, Automatic Control of
Authors: Yu Yih‐Choung 
Published: April 2006

AbstractAutomatic blood pressure control is a technique that regulates the infusion rates of pharmacological agents automatically to maintain a patient’s mean arterial pressure within a desired level. Patients under blood pressure regulation treatment are usually in cardiac surgery or suffering from postsurgical hypertension or other cardiac diseases with abnormal arterial blood pressure. This treatment is usually performed by experienced personnel in the operation room or intensive care unit, which is very difficult and time consuming. An automatic controller that could deliver drugs based on a patient’s physiologic conditions safely and effectively without human intervention would be beneficial to both patients and medical care personnel.This article reviews various automatic control schemes that have been developed to regulate mean arterial pressure for patients with postsurgical hypertension using sodium nitroprusside proportional‐derivative‐integral controllers, adaptive controllers, rule‐based controllers, and neural‐network based controllers are common control strategies described in the literature. A brief description of each control scheme is provided, followed by examples of controller designs from the literature. Evaluations of the controller performance in computer simulation, animal studies, or clinical tests on human subjects are discussed.
Blood Rheology
Authors: Tran‐Son‐Tay Roger , Shyy Wei 
Published: April 2006

AbstractThis article provides the fundamental background for understanding blood rheology, and appreciating its contributions to the improvement of our understanding and assessment of diseases. Because blood rheology is a very broad subject, this article focuses mainly on the role of red blood cell deformability in clinical studies. A review is given of the rheological properties of blood, the impact of cell deformability in clinical situations, the assessment of cell deformabilty using cell filtration and cell elongation, and the most common methods used to measure the rheological properties of blood and individual blood cells.
Bone and Teeth, Properties of
Authors: Lakes Roderic , Katz J. Lawrence 
Published: April 2006

AbstractBone has a variety of functions in the body of which some of the most important are structural in nature: protection of vulnerable body parts, support of the body, and to provide muscle attachments. A knowledge of the mechanical and adaptive properties of bone is useful in the design and use of prostheses that replace a bone or a portion of a bone. Mechanical properties of bone are also of interest in trauma biomechanics and in efforts to prevent injury to the body. As for teeth, they also are replaced by artificial materials which are called upon to perform the mechanical functions of the original tooth. This article contains a survey of known properties of bone and teeth and their components collagen and apatite, with an emphasis on bone and its mechanical properties.
Bone Density Measurement
Authors: Qin Yixian , Mittra Erik 
Published: April 2006

AbstractBone degeneration, i.e., osteoporosis, remains a major public health problem through its association with fragility fractures. Bone mineral density (BMD) measurement is a clinical tool to diagnose osteoporosis or low bone density, predict the risk of fracture, and monitor changes in bone density over time. Assessment of BMD has become as essential element in the early evaluation of patients at risk for osteopenia and osteoporosis. The noninvasive measurement of BMD is done with a variety of technologies for many different skeletal sites. Many image modalities and techniques have been developed to improve the quality and the accuracy of the measurement for bone mineral and dense assessment. There are two major densitometry techniques commonly used in assessing bone density, i.e., radiography‐based densitometry and ultrasound‐based assessment. Dual‐energy X‐ray absorptiometry (DXA) and quantitative ultrasound (QUS) are two current acceptable modalities for bone density testing and the assessment tools for predicting fracture risk. Growing awareness of the impact of osteoporosis on the elderly population and the consequent costs of health care, together with development of new treatments to prevent fractures, have led to a rapid increase in the demand for bone densitometry measurements. The historical development, their working principles, strengths, and limitations of these technologies will be discussed in this article.
Brachytherapy, Intravascular
Authors: Mourtada Firas 
Published: April 2006

Abstract
The scope of this article is on the delivery devices for IVB and tools needed to assess the dosimetric properties of such brachytherapy devices. (Dosimetry is a subspecialty of radiation physics that deals with the measurement of the absorbed dose or dose rate resulting from the interaction of ionizing radiation with matter.) Such techniques are useful and can be applied in other future applications that require delivery of ionizing radiation to a target within a few millimeters from a radioactive source.
Skin Substitute for Burns, Bioactive
Authors: Demling Robert H. , DeSanti Leslie 
Published: April 2006

AbstractThe new generation of skin substitutes are developed to be biologically active. The concept behind providing bioactivity is that the wound healing process can be substantially improved as compared with a simple synthetic barrier‐type dressing. It remains to be seen just how much better this new generation of products will impact the burn wound. To date, the new products to be discussed have not displaced the more inert standard burn wound dressings, but rather are used in conjunction and for quite specific indications.The skin substitutes are initially classified according to whether they are to be used as a temporary wound covering to decrease pain and augment healing or a permanent skin substitute to add to or replace the remaining skin components.The ideal properties and indications for these products will be better clarified after a discussion of the function of normal skin and the effect of a burn on skin integrity.
Capacitive Microsensors for Biomedical Applications
Authors: Tsoukalas D. , Chatzandroulis S. , Goustouridis D. 
Published: April 2006

AbstractThe use of reliable, high performance miniature sensors in the medical field is of growing importance for patient health monitoring. Batch sensor fabrication, as this has been introduced by Integrated Circuit (IC) manufacturing, is an efficient way to produce silicon sensors with desirable characteristics. Since microsensors combine small size with electrical and mechanical principles of operation they constitute together with microactuators what is usually called Microelectromechanical Systems (MEMS). These components are mainly made from silicon and other related materials to explore existing know‐how and infrastructure of silicon technology. All of the above factors have allowed for fast growth of the microsensor field during the last years. This article focuses on physical microsensors used in the medical field that are based on the capacitive approach.
Cardiac Output, Indicator Dilution Measurement of
Authors: Donovan F. M. , Taylor B. C. 
Published: April 2006

AbstractKnowledge of cardiac output is important for determining the hemodynamic status of an individual. A direct measurement of cardiac output is difficult, since to obtain a direct measurement would require collecting and measuring all of the blood pumped from the heart. Therefore it is necessary to develop indirect methods for the measurement of this important parameter. The Fick and other indicator dilution methods are two of the invasive procedures that produce good results. The fundamental equations and theory necessary to understand the indicator dilution methods of measuring cardiac output including the steady‐state Fick method, the transient indicator dilution methods with recirculation, and the thermal dilution method are developed and their application is explained.
Cardiopulmonary Resuscitation
Authors: Grayden Edward 
Published: April 2006

AbstractThis article will first review the history of CPR followed by a detailed analysis of the pulmonary and cardiac physiology relevant to the application of these resuscitative functions. An overview of Emergency Cardiac Care (ECC) will be undertaken to enlighten the reader about the organizational process guiding CPR. The actual mechanism of BLS and ACLS will be then addressed with a brief overview of defibrillators. Finally, the salient points of this article will be summarized and future directions of resuscitation will be explored.
Codes and Regulations: Medical Devices
Authors: Waxler Morris , Kaeding Patricia J. 
Published: April 2006

Abstract
The U.S. Food and Drug Administration (FDA) regulates medical devices according to specific definitions, classifications, requirements, codes, and standards. The FDAs authority and framework for medical device regulation are specified in the Federal Food, Drug, and Cosmetic Act. Pursuant to the Act, FDA determines the entities subject to regulation, evaluates whether products and regulated entities are in compliance, and initiates appropriate regulatory and enforcement actions. The FDAs requirements affect each stage of a medical device’s lifecycle. Some FDA requirements apply to particular periods of a medical device’s lifecycle. Others apply more broadly. Design, technical development, preclinical testing, clinical study, market authorization and approval, postmarket assessment, modification, obsolescence, redesign, and labeling requirements are part of this regulatory framework for medical devices.
Resin‐Based Composites
Authors: Cannon Mark 
Published: April 2006

AbstractComposite dental restorative filling materials are synthetic resins that have had a revolutionary impact on dental practice. No other dental materials have stimulated such rapid change in an inarguably short period of time. The advent of resin‐based composite occurred during the “Golden Age of Dentistry” and mirrored the overall effect that high technology had on society. Virtually everyone has been made aware of “bonding” or “cosmetic dentistry” by the mass media. The success of “bonding” or “cosmetic dentistry” depended on the development of esthetic dental restorative (filling) materials such as resin‐based composites and to the advent of dental adhesives, which allowed for the successful placement of the new esthetic materials.
Computed Tomography
Authors: Dennis Michael J. 
Published: April 2006

AbstractComputed tomograhy (CT), also know as CAT scanning, is a major diagnostic imaging method utilizing the measurement of thousands of X‐ray transmission measurements through the patient to generate detailed cross‐sectional images. The resultant image is a matrix of CT numbers where each picture element or pixel is a scaled value of the linear attenuation coefficient or X‐ray density of the tissue contained in the corresponding volume element or voxel in the patient. The ability to eliminate over and underlying structures from the X‐ray data allows the ability to discern differences of these CT number values to a fraction of a percent. The technology has continued to improve since its development in the 1970s with faster, higher resolution systems to rapidly produce a large number of two‐dimebnsional (2D) axial images, and the use of processing methods to generate three‐dimensional (3D) presentations of the anatomy.Material consider in this article include the basic principles of CT: the evolution of different data acquisition geometries for more rapid scanning; the various components of a CT system; reconstruction methods used to determine the cross‐sectional distribution of densities from the transmission measurements; scan techniques including helical, cardiac, and angiographic scanning, display techniques for presenting the 3D data; factors affecting patient dose; factors affecting resolution and image noise; and CT artifacts or errors that can occur in the images.
Contact Lenses
Authors: Ritchey Eric R. 
Published: April 2006

Abstract
Contact lenses are prescription medical devices applied to the anterior surface of the cornea for the temporary correction of refractive error. Contact lenses can be used successfully to correct a number of refractive error conditions, such as myopia, hyperopia, presbyopia, and aphakia. Currently, there are an estimated 38 million contact lens wearers in the United States and 125 million contact lens wearers worldwide, making contact lenses one of the most commonly prescribed medical devices available. The ability to wear contact lenses successfully is dependent on numerous factors, including but not limited to the contact lens design and materials, corneal health and physiology, the lens to epithelium interface, proper use of lens care solutions, patient compliance, professional fitting and follow‐up care. Unacceptable contact lens fits can lead to deleterious results ranging from poor lens comfort to microbial keratitis and permanent loss of visual acuity.
Cryosurgery
Authors: Gage Andrew A. 
Published: April 2006

Abstract
Cryosurgery is a method of therapy that uses freezing temperatures to achieve curative effects on diseased or abnormal tissues. This article reviews the historical background of cryosurgery, the mechanisms of tissue injury due to freezing, and the techniques of application of freezing temperatures to the tissue. The technical description reviews the types of cryogens and cryosurgical apparatus and the methods of monitoring the freezing process. Clinical uses of cryosurgical techniques for diverse organs and tissues, both neoplastic and non‐neoplastic diseases, are described.
Cutaneous Blood Flow, Doppler Measurement of
Authors: Khaodhiar Lalita , Veves Aristidis 
Published: April 2006

Abstract
The necessity for measuring the skin blood flows occurs in many areas of physiology, pharmacology, and clinical medicine. Although the measurement of blood flow in the large blood vessels in the human body has been performed for centuries, the use of techniques to explore microcirculation have just evolved over the past 30 years. Available tests for assessing the skin microcirculation include tissue pH measurement, radioactive isotope clearance, capillary microscopy, plethysmography, transcutaneous oxygen tension, ultrasonic Doppler flowmetry, and laser Doppler flowmetry.
Defibrillators
Authors: Roth Bradley J. 
Published: April 2006

AbstractA defibrillator is a medical device that delivers an electric shock to a heart that is in ventricular fibrillation. Defibrillators come in two types: external and internal. An Automated External Defibrillator (AED) is designed to deliver a shock through electrodes attached to the body surface. A physician, a paramedic, or even an untrained bystander can use an AED to apply a shock to an unconscious victim. An Implantable Cardioverter Defibrillator (ICD) is surgically implanted into patients who are at risk for ventricular fibrillation. The ICD monitors the electrical activity of the heart and delivers a shock when fibrillation is detected. Both devices operate by charging a capacitor to a high voltage and then discharging it through the heart.
Differential Counts, Automated
Authors: Zelmanovic David , Kunicka Jolanta 
Published: April 2006

AbstractThis article includes a discussion of the cellular properties that are used to automatically analyze white blood cells and describes the techniques used to measure these properties. Examples are provided of the implementation of these techniques on commercial hematology analyzers. Finally, there is a brief discussion of the relative merits of the analysis methods in terms of result accuracy and laboratory efficiency.