bluuebunny/crossref_metadata_2025 huggingface dataset:
Electroconvulsive Therapy
Authors: Foust Milton J. , George Mark S.
Published: April 2006

Electroconvulsive therapy (ECT) was introduced for the first time as a technique for treating psychiatric disorders in 1938. It is an effective treatment for mood disorders and can be used for a number of other conditions including schizoaffective disorder and schizophrenia, especially when these conditions are accompanied by prominent disturbances in mood. The modern technique of ECT consists of brief‐pulse square‐wave alternating current cranial stimulation under general anesthesia with muscle relaxation, oxygenation, and continuous cardiac, blood pressure, oxygen, electromyographic, and electroencephalographic monitoring. The rate of successful acute treatment is high, and serious side effects are uncommon. Areas for further research include combined treatment with ECT and medication as well as new forms of electromagnetic brain stimulation such as repeated transcranial magnetic stimulation (rTMS), magnetic seizure therapy (MST), and vagus nerve stimulation (VNS).
Electrogastrogram
Authors: Chen DZ , Lin Zhiyue
Published: April 2006

Electrogastrogram (EGG), the cutaneous recording of the myoelectrical activity of the stomach using surface electrodes, is attractive due to its noninvasive nature and its correlation with gastric motility. After a slow evolution since its first measurement in 1921, EGG has received more and more attention among investigators and clinicians in the past two decades. Electrogastrogram has become an attractive tool to study the electrophysiology of the stomach and pathophysiology of gastric motility disorders. Numerous studies have reported normal EGG patterns in healthy subjects. A higher prevalence of abnormal EGG patterns, such as gastric dysrhythmias, has been reported in patients with gastrointestinal motility disorders, such as gastroparesis and symptoms of nausea and vomiting. The clinical use of EGG as a diagnostic tool for the assessment of gastrointestinal motility disorders is being explored. Now EGG techniques are becoming increasingly standardized with commercially available hardware–software package. This article covers the following topics: a brief historic review of EGG, basics of gastric myoelectrical activity, measurement and analysis of EGG including multichannel EGG, interpretation of EGG, parameters, clinical applications of EGG, and future development of EGG.
Electromyography
Authors: De Luca Carlo
Published: April 2006

This article provides a rational basis for understanding and using the Electromyographic signal (EMG), the electrical signal that emanates from a contracting muscle. It begins with a brief historical account. It then progresses to a description of the origin and the construct of the EMG signal. A model for the motor unit action potential, the most fundamental electrical unit of the EMG signal, is synthesized and used to derive mathematical expressions for the EMG signal. Applications of the EMG signal for measuring the performance of the muscle are presented. The numerous biochemical, anatomical, geometrical, and physiological factors that influence the characteristics of the EMG signal are described. This influence must be understood and considered when interpreting the EMG signal for a specific use. This is followed by a discussion on the various electrodes (sensors) that can be used to detect the EMG signal, and the relative advantages and disadvantages of each. Characteristics of the electronic equipment for amplifying the signal are provided. Finally, there is a discussion on the common parameters that can be used to extract useful information from the EMG signal.
Electrosurgical Unit (ESU)
Authors: Pearce John
Published: April 2006

“Electrosurgery” means the application of radio frequency (RF) current at frequencies between about 300 kHz and 5 MHz to achieve a desired surgical result; typically, the fusion of tissues or surgical cutting in which the tissue structure is disrupted. The effect is achieved by heating tissues with RF current by resistive dissipation. Controlled application of heat to precisely defined tissue volumes is attained by careful design of the electrodes. Heating and resulting irreversible thermal alterations in tissues may be studied in numerical models as well as experimentally. As with any energy source, there are hazards of use which must be managed by careful technique.
Endoscopes
Authors: Hooper Brett A.
Published: April 2006

This article reviews the history of endoscopes and discusses optical fibers and medical applications.
Evoked Potentials
Authors: Quiroga Rodrigo Quian
Published: April 2006

In this article, we review some of the most common paradigms to elicit evoked potentials and describe basic and more advanced methods of analysis with special emphasis on the information that can be gained from their use. Although we focus in EEG recordings, these ideas also apply to magnetoencephalograpic (MEG) recordings.
Exercise Stress Testing
Authors: Chen Henry , Froehlicher Victor
Published: April 2006

Exercise can be considered the most practical test of cardiac perfusion and function. Exercise testing is a noninvasive tool to evaluate the cardiovascular system’s response to exercise under carefully controlled conditions. Its main uses center around the diagnosis of coronary artery disease and the estimation of prognosis in a wide range of conditions. While there are important technological considerations and the need to be very knowledgable of the guidelines to insure its proper application, exercise testing remains one of the most widely used and valuable noninvasive tools to assess cardiovascular status.
Eye Movement, Measurement Techniques for
Authors: Borah Joshua
Published: April 2006

The terms eye movement measurement, eye tracking, and oculogragphy refer to measurement of the orientation and motion of the eye, either with respect to the head, or with respect to the visual environment. This may include not only rotations of the eye that cause changes in gaze direction, but also rotations of the eyeball about the line of sight, called ocular torsion.

Eye movement measurement devices have long been used for research in reading, various aspects of visual perception and cognition, neurology, human factors, and marketing. In recent years, practical uses have expanded to include as computer usability research, communication devices for the disabled, sports and gait research, Lasik surgery instrumentation, and research requiring simultaneous functional magnetic resonance imaging (f MRI) measurement.

The eye movement measurement techniques currently in most frequent use fall into the major categories of magnetic search coil, a technique that measures magnetically induced current in a tiny wire coil fastened to the eye; electro oculography, which uses surface electrodes to measure the direction of an electrical potential between the cornea and retina; and optical techniques that rely on optical sensors to detect the position or motion of features on the eye. The optical technique category includes many subtypes, and has the largest variety of different systems in current use.

Background theory and system descriptions are presented for eye movement measurement devices in all of the above categories.
Flame Atomic Emission Spectrometry and Atomic Absorption Spectrometry
Authors: Lyon Andrew W. , Lyon Martha E.
Published: April 2006

Observation in the 1700s that candlelight changed color when different materials were introduced into a flame prompted studies that revealed that elements emit characteristic colors of light that consist of line spectra. Kirchhoff’s laws of Spectroscopy were established in the late 1800s and describe both emission and absorption of light. The observation that atoms of each element can emit and absorb light at specific wavelengths is a fundamental property of matter that rapidly became an analytical tool and contributed to development of structural models of the atom. The theoretical basis and instrument components used for flame emission spectrometry (also called flame photometry) and flame and flameless atomic absorption spectroscopy are described with general comments on sensitivity and susceptibility to chemical, spectral, ionization and matrix interferences. Modern instruments that use flame, electrothermal (or flameless) or inductively coupled plasma designs are flexible, reliable and sensitive and are used in reference laboratories to assess the concentration of trace elements and heavy metals in biological fluids to support medical diagnosis and treatment.
Functional Electrical Stimulation
Authors: Venkatasubramanian Ganapriya , Jung Ranu , Sweeney James D.
Published: April 2006

Functional electrical stimulation (FES) is a rehabilitative technique where low level electrical voltages and currents are applied to an individual in order to improve or restore function lost to injury or disease. In its broadest definition, FES includes electrical stimulation technologies that, for example, are aimed at restoration of a sense of hearing for the deaf, vision for the blind, or suppression of seizures in epilepsy or tremors for people with Parkinson's disease. Most FES devices and systems are known then as “neuroprostheses” because through electrical stimulation they artificially modulate the excitability of neural tissue in order to restore function. While sometimes used synonymously with FES, the term functional neuromuscular stimulation (FNS) is most commonly used to describe only those FES technologies that are applied to the neuromuscular system in order to improve quality of life for people disabled by stroke, spinal cord injury, or other neurological conditions that result in impaired motor function (e.g., the abilities to move or breathe). Another technology closely related to FES is that of therapeutic electrical stimulation (TES), wherein electrical stimulation is applied to provide healing or recovery of tissues (e.g., muscle conditioning and strengthening, wound healing). As will be seen, some FES and FNS technologies concurrently provide or rely upon such therapeutic effects in order to successfully restore lost function. For illustrative purposes, much of this article is centered on FNS and related TES devices and technologies.
Gas and Vacuum Systems, Centrally Piped Medical
Authors: Klein Burton
Published: April 2006

This article is intended to give readers a brief look at how and why centrally piped medical gas and vacuum systems were developed, how they operate, what hazards they pose, what standards have been developed to mitigate hazards as well as to standardize operation, and why maintenance of these systems is very important. In a sense, medical gas and vacuum systems are a reflection, in part, of how the practice of medicine has changed over the past 60–70 years: Both systems have become more complex and sophisticated in order to meet and treat more serious illnesses.
Gastrointestinal Hemorrhage
Authors: Britt R.C. , Britt L.D.
Published: April 2006

Gastrointestinal (GI) hemorrhage is a common medical problem, with significant associated morbidity and mortality. Management of GI hemorrhage involves a multidisciplinary approach, including gastroenterologists, surgeons, radiologists, intensivists, and primary care physicians. The three major categories of GI hemorrhage include variceal hemorrhage, nonvariceal upper GI hemorrhage, and lower GI hemorrhage. Initial management includes placement of large‐bore intravenous access for aggressive resuscitation with isotonic fluid, as well as a comprehensive history and physical exam to elicit the source of the bleeding. If the bleeding is felt to be from an upper GI source, early endoscopy is beneficial for both diagnosis and management of the bleeding source. Modalities useful in the management of upper GI bleeding include endoscopic thermal and injection therapy, angiography, pharmacologic therapy, and surgery for recalcitrant bleeding. Diagnostic modalities for lower GI bleeding include nuclear medicine scanning, angiography, and endoscopy. Therapeutic options include endoscopy, angiography, and surgery.
Glucose Sensors
Authors: Rahaghi Farbod N. , Gough David A.
Published: April 2006

Glucose monitoring is essential for the effective treatment of diabetes. Present monitoring approaches based on sample collection are the foundation of self‐care, but require user initiative and are typically not repeated frequently enough to follow blood glucose dynamics. Continuous glucose sensors that are convenient and acceptable to users would make possible several new approaches to treatment of the disease. Development of continuous glucose sensors has proven to be a substantial challenge, but there are now promising candidate sensors nearing clinical introduction.
Heart–Lung Machines
Authors: D’Alessandro David , Michler Robert
Published: April 2006

The heart‐lung machine is perhaps the most important contribution to the advancement of surgery in the last century. This apparatus was designed to perform the functions of both the human heart and the lungs allowing surgeons to suspend normal circulation to repair defects in the heart. The development of a clinically safe and useful machine was the rate‐limiting step to the development of modern cardiac surgery. Since its inception, the heart‐lung machine has enabled the surgical treatment of congenital heart defects, coronary heart disease, valvular heart disease, and end‐stage heart disease with heart transplantation and mechanical assist devices or artificial hearts.

The heart‐lung machine consists of several components that together make up a circuit that diverts blood away from the heart and lungs and returns oxygenated blood to the body. Commercial investment and production of these components has resulted in wide variability in the design of each, but the overall concept is preserved. During an operation, a medical specialist known as a perfusionist operates the heart‐lung machine. The role of the perfusionist is to maintain the circuit, adjust the flow as necessary, prevent air and particulate emboli from entering the circulation, and maintain the various components of the blood within physiologic parameters.
Heart Valve Prostheses, In Vitro Flow Dynamics of
Authors: Biancucci Brian , Ceccio Steven
Published: April 2006

The following discussion will focus on the primary tools, techniques, and data that are of interest when evaluating mitral and aortic valves in vitro.
Heat and Cold, Therapeutic
Authors: Dyson Mary
Published: April 2006

Bone cement has been widely used in orthopedic surgeries since Sir John Charnley first introduced the self‐curing bone cement for the fixation of artificial joints in 1958. Several important aspects of material characteristics of bone cement, including its material compositions, short‐ and long‐term mechanical properties are discussed in this article. This article aims to provide comprehensive information for the orthopedic community on cement applications.

The rationale underlying the use of therapeutic heat (thermotherapy) and cold (cryotherapy) is based on their physiological effects. Heating the tissues by a few degrees centigrade increases tissue metabolism, relieves pain, and accelerates the healing process. Other effects of therapeutic heat include increased joint mobility, vasodiltation, and increased muscle tone. Cooling the tissues by a few degrees centigrade limits secondary damage to soft tissues, nerves, and the brain after trauma. Other effects of therapeutic cold, which should ideally be applied as soon as possible after trauma, include relief of pain, reduction of acute inflammation, decreased joint mobility, and decreased muscle tone. The application of cold, to reduce the extent of damage, may be followed by the application of heat, to accelerate healing.

There are many methods of applying therapeutic heat and cold. Selection of the most appropriate depends on several factors, including the location of the injury, the depth of penetration of the modality, the dimensions of the area to be treated, the ease of application, the duration of application, cost, and convenience. The choice of modality is frequently limited by contraindications.

To use thermotherapy and cryotherapy effectively, the clinician should know:

The physiological effects of heat and cold

What devices are available to produce temperature changes

How they work

When and when not to use them

Their advantages and disadvantages

This article provides this information following a brief description of the history of these therapies.
Hemodynamics
Authors: Segers Patrick , Verdonck Pascal
Published: April 2006

The purpose of this article is to provide the reader with an overview of both established and newer methods and techniques for the analysis of cardiac and arterial function, and heart‐arterial coupling. The focus of the cardiac function analysis is on pressure‐volume loop based methodologies, but some attention is paid to daily in‐hospital practices where volume measurements are commonly unavailable. The major characteristics of the coronary circulation are described. Arterial function analysis includes impedance analysis, and touches both the conceptual ‘lumped parameter’ view of the arterial system, as well as the analysis of pressure and flow waves in terms of forward and backward waves. Indices such as the augmentation index or pulse wave velocity, now commonly referred to as ‘pulse wave analysis’ are also dealt with. The chapter also includes the wave intensity analysis, a more recent time‐domain method to study arterial pressure and flow waves. Heart‐arterial coupling, finally, includes a description of the E
a
−E
max
(arterial elastance‐ventricular elastance) framework, as well as a more model‐based approach of heart‐arterial interaction.
Home Health Care Devices
Authors: Tamura Toshiyo
Published: April 2006

Various monitoring devices for home healthcare and telecare have been proposed and developed, and some of them are commercially available. For home healthcare, there are many opportunities for applying exiting sensor technologies that are also simple to operate. In addition, some of them do not require the sensor to be attached to the body and some offer fully automatic monitoring. This article focuses on recent developments in home healthcare devices.
Human Factors in Medical Devices
Authors: Repperger Daniel W.
Published: April 2006

In this article, we initially discuss human factors as defined by the FDA followed by three classic case studies. The ramifications of legal issues are then presented. Concurrent good human factors methods are then described, followed by some key topic areas including alarms, labeling, automation, and reporting. Future issues regarding human factors and medical devices are subsequently offered with conclusions and future directions of this field depicted.

First, it is instructive to review the present state of affairs on how the FDA defines human factors engineering within the context of when humans interact with medical devices. The term human factors engineering is a persuasive term in the literature describing present FDA standards.
Hyperbaric Medicine
Authors: Persons Barbara L. , Collins Beth , Lineaweaver William C.
Published: April 2006

Hyperbaric medicine involves using monoplace or multiplace hyperbaric chambers to deliver systemic oxygen under pressure to treat a number of medical conditions. The Undersea and Hyperbaric Medical Society approves the use of hyperbaric oxygen (HBO) for the following medical conditions: acute decompression illness, gas embolism, carbon monoxide poisioning, cyanide poisioning, clostridial gas gangrene and necrotizing soft tissue infections, compromised skin grafts and skin flaps, crush injury compartment syndrome and other acute traumatic ischemias, radiation tissue damage, refractory osteomyelitis, and selected problem wounds, acute exceptional blood loss anemia, acute thermal burns, and intracranial abscess. HBO use in treating these conditions is supported by controlled medical trials published in major peer‐reviewed journals and, as such, is evidence‐based. Numerous other experimental uses exist for HBO, such as for cardiac ischemia and for stroke, but these other uses have not yet been sufficiently proven to be beneficial. The effect of HBO is a result of the manifold increase in solubolized oxygen under pressure and its complex physiologic effects and, as such, is completely different from administering 100% oxygen at 1 Atmosphere. These affects include improving immune cell functioning and angiogenesis. More specific details of the history, physics, physiology, and function of HBO will be discussed as well as details of hyperbaric chamber facility design and safety.
Hyperthermia, Systemic
Authors: Rowe‐Horwege R. Wanda
Published: April 2006

Systemic hyperthermia is deliberate heating of the whole body to achieve an elevated core temperature for therapeutic purposes. This practice has centuries of historical precedence and is founded on solid physical and biological principles. Body temperature is tightly controlled by a number of physiological processes to achieve a sustained elevation of core body temperature these must be overcome so that heat input exceeds heat losses. The physics of heat balance in human bodies is described. Numerous methods of systemic heating have been investigated and are presented. Use of radiant energy in the near infrared range is effective in heating and has minimal side effects for the patient. Thus it forms the basis of most commercially available whole‐body hyperthermia machines. The physiology of elevated body temperature and the biology of hyperthermia, along with its toxicities, is discussed in some detail as its understanding is key to development of successful systemic heat based therapies. Cancer is the main focus of whole body hyperthermia, and the rationale for, and state of the art of, cancer treatment is presented. While initial applications of systemic hyperthermia attempted to produce direct killing of malignant cells with maximally tolerated temperatures, it is now appreciated that curative effects may be achieved through lower temperatures sustained for longer durations and by combining systemic hyperthermia with radiation therapy and chemotherapy. Systemic hyperthermia can also be of use in treatment of musculoskeletal disorders, rheumatic diseases, and immune deficiencies. New directions and future applications of whole‐body hyperthermia as an aid immunotherapy, gene therapy, and drug delivery are presented. A resurgence of interest in systemic hyperthermia is predicted along with its emergence from the fringe of medical practice to become established as a mainstream medical treatment.
Image Intensifiers and Fluoroscopy
Authors: Siedband Melvin P.
Published: April 2006

This article details early fluoroscopic systems and the advent of image intensifiers and their progression and improvement to imaging quality.
Immunologically Sensitive Field‐Effect Transistors
Authors: Zachariah Emmanuel S. , Gopalakrishnakone P. , Neuzil Pavel
Published: April 2006

The Immunologically Sensitive Field‐Effect Transistors (IMFETs) represent the amalgamation of the technologies of Solid‐state electronics and Immunodiagnostics. The immunosensor is fabricated by immobilizing immunoagent, preferably, antibody on the gate region of an Ion‐Sensitive Field Effect Transistor (ISFET). Consequently, IMFETs embodying a range of monoclonal antibodies and the unique ISFET transduction mechanism could, in principle, be made possible for detection of a wide array of analytes, ranging from small biomolecules to bacteria. There have been several studies describing the application of ISFET as the IMFET, and they are broadly discussed in two headings, viz., Direct‐acting (label free) IMFET and Indirect‐sensing IMFET. In the label free approach, antibody‐antigen reaction has been monitored without addition of enzyme labels. Whereas the latter approach utilizes the advantage of enzyme label to indirectly monitor the antibody‐antigen reaction with pH‐sensitive ISFET. This chapter describes the challenges met with the development of practical IMFETs, their strengths and limitations.
Immunotherapy
Authors: Li Qiao
Published: April 2006

The immunotherapy of cancer, infectious disease, and autoimmune disease has developed very rapidly during recent years. For example, the current concept of “adoptive T cell immunotherapy of cancer” is quite different from how it was originally conceived. With the development of modern technology in molecular biology, cell biology, immunology, and biochemistry during the last 20 years or so, adoptive immunotherapy has grown from its initial form of a simple “blood cell transfer” into its present process, which involves host vaccination, effector cell activation/polarization and genetic modification. With the use of immune adjuvants and the identification–characterization of tumor‐reactive T cell subsets, or in combination with other therapeutic strategies, adoptively transferred T cells have become much more potent in mediating tumor regression. In addition, studies on the trafficking of infused T cells, cell transfer performed in lymphopenic models, as well as the discovery of novel techniques in immune monitoring for the generation of effector cellsIn vitroand after cell transferIn vivohave provided useful tools to further improve the therapeutic efficacy of this approach.
Bioimpedance in Cardiovascular Medicine
Authors: Hettrick Douglas A. , Zielinski Todd M.
Published: April 2006

The terms bioimpedance or tissue impedance describe both the resistive and reactive components of tissue at the applied stimulus frequency. The capacitive reactive components of the measured tissue impedance change at higher frequencies due to the relative conductive properties of tissue fluids and cellular membranes. It is the resistive and reactive applications of bioimpedance that will be discussed in this article.
Intraaortic Balloon Pump
Authors: Weller Peter , Morrow Darren
Published: April 2006

The intra‐aortic balloon pump (IABP) is an implanted cardiac assist device that utilises the principle of counterpulsation to provide temporary assistance to the failing heart. The balloon inflates during diastole (relaxation) and deflates before systole (contraction). This has two primary effects. First, it causes a decrease in the peak aortic blood pressure during systole, called systolic unloading. Second, it causes an increase in the mean aortic blood pressure during diastole, called diastolic augmentation.

Systolic unloading decreases the oxygen demand of the heart and is enhanced by earlier balloon deflation. Diastolic augmentation increases the oxygen supply to the heart and is enhanced by later balloon deflation. The IABP therefore improves the myocardial oxygen balance and this can help the failing heart to recover. Furthermore, fine adjustment of the balloon deflation time can maximize this improvement.

This article introduces the medical theory and need for intra‐aortic balloon pumping. A brief historical background is then presented. The techniques and principles of counterpulsation are then described. The article concludes with an examination of current developments and problems in this arena.
Ion‐Sensitive Field‐Effect Transistors
Authors: Hammond Paul A. , Cumming David R.S.
Published: April 2006

This article reviews the site‐binding model and the development, packaging, circuitry, and applications of ion‐sensitive field‐effect transistors.
Ligament and Tendon, Properties of
Authors: Azangwe G , Aspden RM
Published: April 2006

First, this article considers the components of the tissue, not from a biochemical point of view, but as components that may be combined to produce mechanically stable materials. The constituents are considered in terms of the matrix in which are embedded fibers of collagen and varying amounts of elastin. Following this is a discussion of the ways these components interact in ligaments and tendons to yield composite materials with the required mechanical properties. A consideration of some of the ways in which ligaments and tendons may be damaged, and the mechanisms by which they might recover or be repaired, leads to a final, brief review of their surgical replacement. A small section on work being conducted in order to produce a tissue engineered ligament and tendon is also included.
Magnetic Resonance Imaging
Authors: Block W. F. , Alexander A. L. , Fain S. B. , Meyerend M. E. , Moran C. J. , Reeder S. B , Vigen K. K. , Wieben O. , Brittain J. H.
Published: April 2006

Magnetic resonance imaging (MRI) moved out of the exclusive realm of academia and into widespread clinical practice in the 1980s. Relatively quickly, MRI became the modality of choice for several head, spine, and musculoskeletal imaging exams due to tis excellent soft tissue contrast. Although the plateau of MRI’s development and utilization has often been predicted, it continues to grow through being an amazingly adaptive technology. New mechanisms of generating image contrast have allowed the modality to go beyond the study of anatomical structure and deliver functional physiological informaion. A description of the nuclear magnetic resonance (NMR) phenomena, methods to spatially encode the NMR signal, image contrast mechanisms, and emerging appliactions are provided.
Mammography
Authors: Lin Pei‐Jan Paul
Published: April 2006

X‐ray mammography has been the primary imaging modality employed in the early detection of breast cancer for the past three decades. This article covers a brief historical development, in parallel with discussions in some details, with respect to the physics of mammography. The hardware of mammography equipment including the X‐ray tubes, generators, and the image receptors are manufactured with different engineering implementation. Thus, specific commercial products are introduced to describe the technological achievements of typical representative designs. Since the radiology community as a whole is gearing toward the filmless “digital” era, the screen‐film mammography is briefly discussed while the digital mammography including computed radiography (CR) and digital radiography (DR) are given more attention in this article. Mammography products that are readily available in the U.S. market are described. This is due primarily to the fact any medical devices are regulated by the U.S. Food and Drug Administration (FDA) in the United States, but had profound effect on the equipment design and development of mammography products. The mammography related equipment, in particular, is regulated under the Mammography Quality Standards Act (MQSA), originally enacted in 1990.
Medical Physics Literature
Authors: Orton Colin
Published: April 2006

Medical physics publications include books, proceedings, reports, monographs, and journals. Of special interest are the publications of two leading medical physics organizations, the Institute of Physics and Engineering in Medicine (IPEM) in the UK, and the American Association of Physicists in Medicine (AAPM) in North America. These two organizations between them have published hundreds of reports, monographs, and meeting proceedings that are used as reference materials throughout the world. From the IPEM many of these are published by the Institute of Physics Publishing (IOPP) in Bristol, UK, and from the AAPM many are published by either the American Institute of Physics (AIP) or Medical Physics Publishing (Madison, WI). In this Section we will present references to all these publications, as well as those of other organizations and independent publishers. The various primary and secondary journals will also be referenced.
Mobility Aids
Authors: Cooper Rory , Wolf Erik , Collins Diane , Chavez Eliana , Pearlman Jon , Karmarkar Amol , Cooper Rosemarie
Published: April 2006

The uses of mobility aids are critical to the lives of millions of people around the world with mobility impairments. Mobility aids, whether it is a wheelchair, a walker, or a prosthetic limb, give their users the independence in their everyday lives to work, play, and perform their activities of daily living. Properly prescribed mobility aids also assist in the safety of their users by reducing falls, and reducing fatigue and injuries to the upper extremities. The dramatic advancements in technology in the past decades have allowed mobility aids to be accessible to a far greater population of users, and have given users, even those with very limited functional mobility, the means to participate in whichever activities they please and also to perform their normal daily activities.
Monitoring, Hemodynamic
Authors: Gardner Reed M.
Published: April 2006

Hemodynamic monitoring relates to the measurements, display, and quantitation of parameters measured from the human cardiovascular system. For critically ill patients, the measurement and display of parameters derived from a broad array of sensors and systems, provides physicians and nurses to better understand and manage the care of the patients. Several of the hemodynamic parameters are obtained from noninvasive electrodes and probes, while others require placement of invasive catheters and injection of fluid to perform the measures. As with all systems that measure a patient’s physiological parameters, it is important to understand how to accurately and consistently measure these parameters. This article provides an insight into how to reliably and consistently measure important hemodynamic parameters needed to optimally care for these critically ill patients.
Monitoring, Intracranial Pressure
Authors: Daley Michael L. , Piper Ian
Published: April 2006

The craniospinal axis consists of all neural tissue and contiguous fluid‐filled spaces within the cranium and spinal sac. Intracranial pressure (ICP) is a nonuniform pressure recorded within the craniospinal axis. Although the subject of intracranial pressure dates back to over 200 ago, both the invasive monitoring procedure required to measure ICP with its accompanying risk of infection and the nonunique nature of the extravascular pressure measurement have retarded the development of knowledge in this area. As a result, the intent of this article is to provide the reader with a broad perspective ICP monitoring by providing background material on (1) the physiological and anatomical characteristics of the craniospinal, (2) a history of instrumentation techniques including the most recent advances, (3) a brief review of significant clinical ICP monitoring studies with an emphasis on severe head injury, (4) a review of analysis methods, and (5) models of ICP dynamics related to analysis.
Monitoring, Umbilical Artery and Vein
Authors: Elsharydah Ahmad , Wang Haibo , Cork Randall C.
Published: April 2006

This article addresses the potential benefits of umbilical vessel catheters and associated monitoring devices. It sheds light on the catheters and monitors available on the market and explains the complications and the risks of these catheters. Furthermore, this article looks at the direction of this technology in the future, and it tries to stimulate development of new technology for use in the monitoring of critically ill newborn infants.
Neutron Activation Analysis
Authors: Hou Xiaolin
Published: April 2006

Neutron activation analysis (NAA) is an elemental analysis technique, which is based on the excitation of the atomic nucleus of an isotope of element with neutrons, and the emission of the specific gamma rays from the excited nucleus by decay. Due to the absence of a blank and less matrix contribution, NAA is therefore suitable for the analysis of biomedical materials, and has been successfully applied for trace element biomedical study and clinical analysis. A nuclear reactor is normally used as a neutron source for the determination of trace elements; the produced radionuclides are then measured by a gamma detector consisting of a germanium detector and a gamma spectrometry system. The theory, equipment and detailed methodology, and analytical quality assurance are discussed in this article. Some applications are also highlighted.
Neutron Beam Therapy
Authors: Maughan Richard L.
Published: April 2006

The neutron was discovered by James Chadwick in 1932; by 1938 Robert Stone, in collaboration with Ernest Lawrence, was using a cyclotron produced fast neutron beam to treat human tumors. These original clinical trials were unsuccessful because of the poor understanding of the radiobiology of neutrons. Later, radiobiological studies established tumor hypoxia and radiosensitivity variations at different phases of the cell cycle as rationales for fast neutron therapy. Clinical studies during the early 1970s demonstrated that neutron therapy was a potentially beneficial modality in the treatment of malignant disease and definitive controlled clinical trials followed.

Increased interest in neutron therapy lead to the definition of minimum specifications for therapeutic fast neutron beam treatment facilities. These specifications included beam dose rate, penetration, collimation, and reliability. The parameters used to characterize fast neutron beams for therapeutic use include neutron yield (dose rate), the neutron energy spectrum, beam intensity profiles, and microdosimetric data. The most prolific neutron producing nuclear reactions occur when high‐energy proton or deuteron beams are incident on a solid beryllium target, or when the deuterium–deuterium or deuterium–tritium fusion reactions are employed. The relative merits of these different methods of neutron production are discussed in detail.

There have been a total of 34 centers that have treated patients with fast neutron therapy of which 6 are currently operational. The state‐of‐the‐art facilities all use cyclotrons to accelerate protons or deuterons to energies >48 MeV; they use multileaf or multirod collimators to shape the beams to the tumor contour. The latest facility uses a compact deuteron superconducting cyclotron, which offers several advantages over conventional room temperature devices.
Nuclear Medicine Instrumentation
Authors: Williams Lawrence E.
Published: April 2006

Nuclear medicine uses a variety of ionization detectors to measure radioactivity attached to pharmaceuticals designed to target specific tissues and even moleculesIn vivo. The targeting agents include naturally occurring molecules, their engineered variants, and nanostructures. Radioactive labels must emit γ rays (photons) to allow imaging, but beta or alpha emissions are used in radiotherapy of cancer. Both two‐dimensional (2D) and three‐dimensional (3D) images can be produced. The gamma camera is the most common imaging device with positron emission tomographic (PET) scanners becoming very popular because of their tomographic and quantitative outputs. Hybrid devices using gamma camera and computed tomography (CT) or PET and CT on the same scanning bed have been developed to allow better correlation of regions of elevated radioactivity with physiological structures. Small animal versions of these instruments and their hybrids are available for radiopharmaceutical research studies.
Nutrition, Parenteral
Authors: Silberman Howard
Published: April 2006

Parenteral nutrition refers to methods that provide all required nutrients intravenously. This major advance in medical therapeutics is indicated for individuals with medical conditions that preclude safe or effective oral or enteral nutrition. Nutrient solutions provide nonprotein calories as glucose or lipids or a combination thereof, synthetic amino acids as the source for protein synthesis, electrolytes, trace elements, vitamins, and essential fatty acids. Patients receiving such therapy, either in the hospital or at home, require careful monitoring, optimally by a dedicated team, to avoid complications, such as infection or metabolic derangements.
Ocular Fundus Reflectometry
Authors: Kulkarni Amol D. , Dattawadkar Amruta M.
Published: April 2006

A qualitative method for observation of the light reflected at the fundus was developed by Helmhotz in 1851. However, there was need for quantitative assessment and with the introduction of microprocessors, it was possible to measure spatial and spectral distribution of reflectance. Experimental models of observed wavelength dependence and reflectance of light from macula were initiated. The role of these experimental models using fundus reflectometry in basic and clinical research is summarized in the present chapter.
Office Automation Systems
Authors: Cardoso Jorge
Published: April 2006

Nowadays, the use of office automation systems is almost unavoidable in healthcare organizations. These systems allow the automation of much of the administrative work carried out by healthcare professionals and can typically be used to manage appointment scheduling, electronic medical claims submission, medical billing, patient and insurance ledgers, and patient statements. The correct use of these systems can dramatically altered the manner healthcare organizations conduct their daily business by automating the tasks performed by professionals. It is therefore indispensable to understand the objectives and functionalities of the various office automation systems that are available.
Optical Sensors
Authors: Mendelson Yitzhak
Published: April 2006

The fundamental principle of optical sensors is based on the change in optical properties of a biological or physical medium. Optical sensors play an important role in a variety of biomedical, clinical, and environmental measurements. This article reviews the basic concept employed in the development of optical sensors, including specific examples how optical sensors are being utilized for real‐timein vivoandex‐vivomeasurement of clinically signifially significant biochemical variables.
Orthopedics, Prosthesis Fixation for
Authors: Prendergast Patrick J.
Published: April 2006

Methods of fixation of orthopedic implants include (1) use of a grouting polymer (polymethylmethacrylate) to interlock the prosthesis to the bone and (2) osseointegration, which relies on ingrowth of the bone into the implant surface. Osseointegration takes several forms involving a structured surface (wire mesh, beads, etc.), sometimes coupled with an osteoconductive layer (e.g., a hydroxyapatite coating). Both approaches are in wide use in all kinds of joint replacement. In some cases, one side of a joint replacement prosthesis is fixated with cement and the other by osseointegration; such replacements are called hybrid replacements. Both approaches are undergoing continuous development: Fixation with bone cement is improving with each new generation of cementing techniques, and improvements may include bioactive cements in the future; osseointegration is undergoing improvements of osteoconductive coatings, including the addition of growth factors and a better understanding of the relationship between implant stability and bone ingrowth. An overview is given of fixation used in the main orthopedic implant categories.
Oxygen Monitoring
Authors: Barker Steven J.
Published: April 2006

This article reviews recent advances in the monitoring of patient oxygenation. We summarize the transport of oxygen from the atmosphere to the cell, and describe monitors that function at four stages of the O2 transport process. These four stages include respired gas, arterial blood, tissue, and venous blood. History and recent developments in pulse oximetry will be discussed. Continuous intraarterial blood‐gas sensors will be described and contrasted with other oxygen monitors. Finally, tissue oxygen monitoring and mixed‐venous oximetry are discussed.
Phantom Materials in Radiology
Authors: Watanabe Yoichi , Constantinou C.
Published: April 2006

In radiology, phantoms are utilized to estimate radiation dose delivered to patients and evaluate the quality of imaging systems. Hence, the material of the phantoms should closely mimic the human tissue; in particular, the radiological characteristics of the material must be similar to that of the tissue. This article reviews materials used to manufacture phantoms for radiology applications. In the first section, basic physics relevant to the phantom material and radiation interaction with matter is discussed. A brief history of the phantom material for radiology is offered. The second section gives extensive discussion on the materials mainly developed by D.R.White, C.Constantinou, and co‐workers in late 1970s to early 1980s. Their materials were made based on epoxy resin. They produced tissue‐equivalent materials mimicking 15 different tissue types. Detailed description on manufacturing methods and the results of evaluation is presented. Since their seminal work other investigators developed tissue‐equivalent materials by using polyethylene and polyurethane as base. Short discussion on those newer developments is given. The third section presents, how those materials are used for radiation dosimetry, radiation therapy, and diagnostic radiology. Our discussion on applications will be limited to the phantoms used with photons and electrons since most medical applications utilize those particles. The last section is devoted to speculative discussion on what types of phantom and material will be developed in the near future.
Piezoelectric Sensors
Authors: Li Yanbin , Su Xiao‐Li
Published: April 2006

Piezoelectric sensors have been developed based on very established theories in electricity, mass, and viscoelasticity and with commercially available instruments such as quartz crystal microbalance. Piezoelectric sensors have shown their advantages over other sensors in terms of sensitivity, versatility, label free, low cost, and simplicity. They have been applied to the biomedical area mainly in the forms of immunosensors and genosensors for rapid detection of bacteria, viruses and proteins, and DNA/RNA hybridization, respectively. However, the detection limit and reusable electrodes of piezoelectric sensors need to be improved for more applications in biomedical analyses.
Polymeric Materials
Authors: Liu Xiaohua , Shanmugasundaram Shobana , Arinzeh Treena Livingston
Published: April 2006

This article aims to provide basic and contemporary information on polymeric materials used in medical devices and instrumentation. The fundamental concepts and features of polymeric materials are introduced in the first section. In the second section, the major commodity polymers used in medicine are reviewed in terms of their basic chemical and physical properties. The main part of this article, however, is devoted to polymers in biomedical engineering applications, including tissue engineering and drug delivery systems.
Radiation Dose Planning, Computer‐Aided
Authors: Li Jonathan G. , Xing Lei
Published: April 2006

Radiation therapy aims at delivering a desired radiation dose to the intended volume while limiting the dose to surrounding healthy tissues as much as possible. The purpose of treatment planning is to design treatment strategies to best achieve such goals, and to estimate the radiation dose throughout the irradiated volume before the start of the treatment. Thanks to the rapid developments in computer and medical imaging technologies, treatment planning can now be done efficiently under the guidance of the patient’s internal anatomy in three dimensions, incorporating possibly functional and metabolic information with ever increasing resolution and clarity. This article reviews key components in the computer‐aided radiation dose planning, including virtual simulation, image registration, three‐dimensional dose calculation, treatment plan optimization, and treatment plan evaluation, emphasizing specifically the impact of computer technology on these recent developments. As we are ascending into an era of image‐guided radiation therapy with computer‐controlled delivery and real‐time image guidance and feedback, advanced computer technology will play an ever increasingly significant role in radiation oncology.
Radiation Dosimetry for Oncology
Authors: McEwen Malcom
Published: April 2006

This article aims to present a complete and basic review of radiation dosimetry for radiation oncology using external photon and electron beams. Basic quantities are defined and the problems involved in measuring absorbed dose are highlighted. A wide range of primary and secondary measurement techniques are described together with the formalism for calibrating dosimeters.