bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermocouples
Authors: Wren Joakim , Loyd Dan 
Published: April 2006

Abstract
Thermocouples are widely used in various applications in medicine and biomedical engineering. The sensors are accurate, flexible, well documented, and not too expensive. Thus they are considered to have the best cost/performance ratio for many applications.
Thermocouples are based on the thermoelectric Seebeck effect, which gives an electric potential between the junctions of two dissimilar metallic conductors when the junctions are held at different temperatures. Virtually every pair of metallic conductors are possible to use, but for practical reasons standardized thermocouples with determined thermoelectric properties and temperature/potential relation are used.
As all temperature sensor thermocouples are associated with various kinds of measurement errors. Some are specific for thermocouples, but the most important is based on the fact that every contact sensor only measures its own temperature. The sensor should therefore be in good thermal contact with the measuring object in order to obtain an accurate temperature at a reasonable time.
Depending on, for example, the present temperature gradients and the heat flux in the probe compared to its surroundings, significant and even substantial deviations and uncertainties can easily occur. Another important source of measurement errors is electromagnetic (EM) interference, which is particular troublesome in EM induced thermal treatment applications when temperature measurement is carried out in strong fields.
Integrated Circuit Temperature Sensor
Authors: Togawa Tatsuo 
Published: April 2006

AbstractTemperature can affect the electronic characteristics of semiconductor devices. Although this is a disadvantage in many applications, especially for analogue devices, it may be turned into an advantage if such a device is used as a temperature sensor. In principle, any parameter in such a device having a temperature coefficient can be used for temperature measurement. For example, a temperature telemetry capsule, in which a blocking oscillator frequency varies with temperature, has been developed for measuring gastrointestinal temperature.
Tooth and Jaw, Biomechanics of
Authors: Müftü Sinan , Müftü Ali 
Published: April 2006

AbstractThe teeth and jaw perform the critical function of initiating the digestion by breaking the food into smaller sizes. Mastication is defined as the action of chewing foods. Biomechanical investigations of tooth and jaw are primarly involved with the mastication system. The masticatory system is composed of the dentition, bones, ligaments, muscles, and the temporomandibular joint (TMJ). The aim of biomechanical investigations of the masticatory system is to understand the fundamental relations between anatomy and function and, thus, either provide guidance to clinicians in existing treatment modes or help design new ones. In this article the functional anatomy, biomechanics of mastication, and the biomechanical aspects of prosthodontic treatments are presented. The fundamental definitions of force, stress, strain, and material properties are defined. The relevant material properties for the components of the masticatory system are reported. Biomechanical models and results related to the jaw open–close motions, TMJ loading, deformations of the mandible, and effect of endosseous implants are presented.
Tracer Kinetics
Authors: Di Bella Edward V. R. 
Published: April 2006

Abstract
Tracer kinetics refers to the changing distribution of a tracer that provides information regarding a biological system. The tracer may be introduced by injection into the bloodstream, or inhaled, or in some cases be native. By definition, the tracer is present in relatively small (trace) amounts so that it has little or no effect on the system being studied.
High Frequency Ventilation
Authors: Bunnell J. Bert 
Published: April 2006

AbstractHigh frequency ventilators (HFVs) were developed to lessen the lung injury caused by conventional positive pressure ventilators (CVs). Although HFVs use positive pressure, the magnitude of the pressure that reaches the distal areas of the lungs is much lower, and their tidal volumes are a fraction of those used during normal breathing. Thus, HFVs are inherently gentler than CVs, and their use in the treatment of prematurely born infants would appear to be most desirable. However, after >20 years of clinical use, it is still unclear to many clinicians whether HFVs are safe or effective.Most clinical trials applying HFVs to neonates have demonstrated decreased chronic lung disease with no increase in adverse side effects. Some trials conducted with children and adults in severe respiratory failure demonstrated increased survival. Other trials have shown no advantages and increased adverse side effects. Application strategies appear to be essential for successful outcomes, but better equipment design is also needed.Given the skill and training needed to master HFVs, their use may be considered “risky” indefinitely.
X‐Rays: Interaction with Matter
Authors: Sethi Anil 
Published: April 2006

Abstract
A photon in an X‐ray beam that passes through a medium is likely to undergo one of three fates: complete absorption, scatter, or transmission. The first two processes contribute to X‐ray beam attenuation. Five main interactions can cause attenuation of photons: (1) coherent scattering, (2) photoelectric effect, (3) Compton scattering, (4) pair producion, and (5) photodisintegration. How much of the beam gets attenuated depends on which interaction process dominates. This in turn depends on the incident photon energy and the medium compositon. Broadly speaking, coherent scattering is most important at low photon energies and photondisinteration at high energies, whereas the other interactions are likely to occur at intermediate photon energies. The rich physics of interaction processes is presented in this article. We also define various attenuation coefficients, explain their dependence on photon energy and medium composition, and describle how they contribute to many exciting phenomena observed in medical physics.
X‐Rays, Production of
Authors: Horn Bruce 
Published: April 2006

Abstract
Discovered by Wilhelm Roentgen in 1895, X rays are commonly used for many medical diagnostic imaging procedures—from a simple chest radiograph to a multislice computed tomography exam. X‐ray tube components are contained within an evacuated glass envelope that allows a focused beam of electrons to interact with a metal target to produce X rays by two methods: bremsstrahlung and characteristic X rays. This process is relatively inefficient because most of the electrons’ energy results in heat that must be dissipated to avoid failure of the tube. In addition, the size of the focus of the electron beam impinging on the target directly affects the image quality of clinical procedures. Due to these competing factors, an X‐ray tube design must represent the right balance between imaging quality and heat dissipation for a particular clinical application.
Tissue Ablation
Authors: Haemmerich Dieter 
Published: April 2006

AbstractTissue ablation is the destruction of diseased tissue, with the aim to cure a disease. Tissue destruction is achieved by thermal methods, or by application of chemical substances. Thermal methods cause either local heating or cooling of the tissue to lethal temperatures (typically below −40 deg C, or above 50 deg C). A number of different physical principles are employed for heating (radiofrequency electric current, microwaves, laser, ultrasound), and cooling tissue. Current clinical applications include treatment of heart arrhythmia, cancer (liver, lung, brain, kidney, bone, prostate), uterine bleeding, varicose veins, and enlarged prostate, with other emerging applications. During the ablation procedure, an applicator is introduced into the treatment site under imaging guidance. Then the tissue region around the applicator is ablated, destroying the diseased tissue area.
Computed Tomography Screening
Authors: Brenner David J. 
Published: April 2006

Abstract
Computed tomography (CT) has revolutionized much of medical imaging by allowing a three dimensional view of the organ or part of the body of interest. As of 2005, about 60 million CT scans are being performed each year in the USA. The use of CT for mass screening is a more recent innovation, driven in part by much increased availability and convenience of CT scans. Three applications, each of which will be discussed, have been suggested for CT‐based screening, for early stage lung cancer in smokers and ex smokers; for lesions in the colon (virtual colonoscopy); for general screening for many diseases in the whole body (full‐body screening). All these three modalities, as of 2005, are quite new, and a general consensus has not yet been reached about their efficacy. There is an added issue for CT‐based screening modalities, namely the significant x‐ray radiation exposures involved: the potential benefits of any CT‐based screening procedure must, in addition to more general efficacy issues, significantly outweigh any potential harm from repeated low‐dose x‐ray exposures.
Computed Tomography Simulator
Authors: Tang Xiangyang , Wang Ge 
Published: April 2006

Abstract
A computed tomography simulator (CTsimulator) originally referred to the combination of a radiation therapy dedicated (RT‐dedicated) CT scanner and a simulation workstation that is used for treatment planning in three‐dimensional (3D) conformal radiation therapy. Except for a larger gantry aperture and display field of view (DFOV), as well as a flat top patient couch, an RT‐dedicated CT scanner is virtually identical to a diagnostic CT scanner. The simulation workstation consists of a high quality display screen and a simulation software package. Based on the 3D patient data set acquired by an RT‐dedicated CT scanner, a treatment simulation is conducted to make sure an optimized 3D conformal radiation therapy be delivered to all of the targeted cancerous tumor volume while the inevitable radiation dose absorbed by surrounding normal tissues or organs is as little as possible. Although a CT scanner is currently preferable, other modalities, such as magnetic resonance imaging (MRI), positron emission tomography (PET), or ultrasound, can also be utilized to acquire 3D patient data set for treatment simulation (viz., virtual simulator). In a simulation process, numerous modern 3D visualization techniques, such as 3D volume rendering and surface rendering, are utilized to facilitate anatomic structure identification and radiation beam designing, take care of geometrical uncertainty caused by patient organ motion, such as breathing, swallowing, and assure spatial integrity between an RT‐dedicated CT scanner and a treatment machine. In addition to being employed in conventional 3D conformal radiation therapy, a CT simulator can be utilized in advanced 3D conformal radiation therapy, such as intensity modulated radiation therapy, tomotherapy, or radiosurgery. With the development of advanced 3D conformal radiation therapy techniques, more radiation therapy treatment planning systems are including the functionality of a stand‐alone CT simulator as an integrated component to accomplish an optimized radiation therapy via much more complicated 3D conformal beam‐forming techniques.
DNASequencing
Authors: Tsaftaris Sotirios A. , Katsaggelos Aggelos K. 
Published: April 2006

AbstractUnderstanding how DNA sequencing works is the objective of this article, which is organized as follows. First, a very short introduction into the chemistry of the DNA molecule is provided. Subsequently, some of the basic principles used by common sequencing techniques are presented. This analysis is followed by a presentation of the most commonly available techniques and equipment. This article concludes with the presention of some of the most promising techniques for DNA sequencing in the future.
Drug Delivery Systems
Authors: Paolino Donatella , Sinha Piyush , Fresta Massimo , Ferrari Mauro 
Published: April 2006

AbstractTo obtain a given therapeutic response, the suitable amount of the active drug must be absorbed and transported to the site of action at the right time and the rate of input can then be adjusted to produce the concentrations required to maintain the level of the effect for as long as necessary. The distribution of the drug to tissues other than the sites of action and organs of elimination is unnecessary, wasteful, and a potential cause of toxicity. The modification of the means of delivering the drug by projecting and preparing new advanced drug delivery devices can improve therapy. The aim of advanced drug delivery devices is to control (1) the drug release rate from formulations or dosage forms, (2) the drug rate to reach absorbing membranes and surfaces, and (3) the site‐specific drug release. The control of drug release and the control of body distribution are the two most important features of the various drug delivery devices. The most important drug delivery devices were taken into consideration and their most usefull and successful applications in disease therapy were discussed. In particular, the attention was focused on the use of microelectro‐mechanical‐systems, cyclodextrins (the most representative of molecular drug delivery systems), microemulsion and organogel (supramolecular aggregates), and colloidal carriers (liposomes, niosomes, ethosomes, ultradeformable vesicles, nanoparticles) for delivery of drugs.
Engineered Tissue
Authors: Rutkowski Gregory E. 
Published: April 2006

AbstractEngineered tissue is developed using the principles of engineering in combination with the life sciences to create implants that can be used to repair tissue lost to injury or disease. The three main components of engineered tissue are cells to enhance regeneration or replace lost tissue, a biodegradable matrix to hold cells together and promote tissue integration, and chemical factors to stimulate regeneration. Almost every tissue of the human body is currently being investigated as a candidate for engineered tissue repair. With advances in biodegradable polymers, stem cell technology, and immune regulation, engineered tissue has the potential to dramatically change healthcare by improving the quality of life of those for whom it was not previously possible.
Gamma Knife
Authors: Goetsch Steven J. 
Published: April 2006

Abstract
The Leksell Gamma Knife is the largest and costliest medical device ever created. It is designed to treat human patients with brain tumors and other abnormalities. A stereotactic headframe is affixed to the patients skull, a brain imaging study is then obtained, and a specialized computer is used to plan the treatment. The patient is placed on a treatment couch attached to the 22‐ton central body of the device, which contains 201 powerful radioactive cobalt‐60 sources. The patient is transported forward to the treatment position where the 201 sources converge with exquisite precision to irradiate the brain tumor (or lesion) while sparing the adjoining normal brain. This radiosurgery procedure can be used instead of open surgery, which is typically more costly, invasive, and risky. The device has been in use since 1968 and has been used to treat >229,000 patients with primary cancerous brain tumors, metastatic brain tumors, nonmalignant brain tumors, arteriovenous malformations, and functional neurological disorders. It is manufactured exclusively by Elekta Instruments, AB of Stockholm, Sweden. More than 180 units are in use worldwide, about one‐half of them in the United States. The instrument has enjoyed widespread clinical acceptance in the last 10 years by neurosurgeons and radiation oncologists who wish to use minimally invasive techniques to treat brain tumors and other disorders.
Imaging Devices
Authors: Rivard Mark J. , Van den Heuval Frank 
Published: April 2006

Abstract
Electronic portal imaging detectors (EPIDs) are devices that electronically capture the photon energy fluence transmitted through a patient irradiated during treatment, and allow direct digitization of the image. This image is then immediately available for visualization on a computer screen and electronic storage. A variety of technologies have been explored in the past two decades. These include camera based systems, liquid ionization chambers, linear arrays of silicon diode detectors, and flat‐panel displays composed of thin film technology (TFT) integrated circuits. TFT EPIDs permit high imaging resolution, high signal‐to‐noise ratios, and high photon detection efficiencies at reasonable cost. EPIDs permit digital comparisons of the simulated treatment plan with the resultant radiotherapy implementation. EPIDs are quickly replacing radiographic film as an important tool for providing direct confirm treatment delivery. Due to the electronic nature of the system, on‐ and off‐line image analysis is possible for augmenting patient positioning, artifact removal, imaging processing, and evaluation. While increasing the rate of image acquisition, patient throughput is largely unimpeded and improvements in radiotherapy delivery result. EPIDs can reduce the incidence and extent of errors made during radiation treatment delivery. Due to the electronic nature of EPID measurement of the photon energy fluence exiting a patient, one can perform exit dosimetry and quantitative comparisons with treatment planning intentions. EPID quality assurance is described in the 2001 Task Group No. 58 protocol of the American Association of Physicists in Medicine. Daily, monthly, and annual tests are performed to assure the EPID is reliable for clinical use.
Microbioreactors
Authors: Zhu Xiaoyue , Bersano‐Begey Tommaso , Kamotani Yoko , Takayama Shuichi 
Published: April 2006

AbstractRecent advances in micro‐ and nanotechnologies coupled with the need in biology and medicine to perform cellular scale studies and productions have led to the emergence of a variety of microscale biological reaction systems. These microbioreactors are promising as low cost modules for optimizing bioproduction processes, highly parallel analytical platforms for screening pharmaceutical drugs, therapeutic implements for treating disorders and deficiencies, and examination tools for exploring basic physiological responses and biological reactions. This article summarizes the basic concepts, designs, and applications of microbioreactors with a special focus on medical, pharmaceutical, and cell biological applications. Important concepts include scaling laws and how the small size of the microbioreactors affects fluid flow, mixing, mass transport, heat transfer, and sterilization. Examples of specific microbioreactors for fermentation, drug toxicity screening, drug administration, assisted reproduction, and basic cell biological and physiological studies are also discussed. Microscale phenomena provide both a challenge and an opportunity for the development of microbioreactors.
Micropower for Medical Applications
Authors: Kang Ji Yoon 
Published: April 2006

AbstractThis article reviews the recent development of micropower devices in view of medical applications. Microelectromechanical system technology makes implantable devices smaller and cheaper recently, however, developing micropower source of implant device is still challenging. Micropower is classified into two categories: energy storage or energy generation. Current research on miniaturized batteries like fuel cells, thin‐film battery, and micromachined battery are surveyed and their application for implant devices is discussed. Several microfabricated power generators using vibration and body heat are compared and their applicability to medical devices is considered. In the future, a miniaturized battery with high energy density and high power will be the main power source, and a micropower generator will recharge the consumed energy as an auxiliary device.
Microscopy, Scanning Force
Authors: Wojcikiewicz Ewa P. , Kwak Kwanj Joo , Moy Vincent T. 
Published: April 2006

Abstract
Recent advances in technology have allowed us to study our world at molecular, even subatomic, resolution. One of the devices in the forefront of such studies is the atomic force microscope (AFM), which is a relatively complex device with two major applications. It can be used for imaging of biological samples in near‐physiological conditions at atomic‐level resolution. The AFM can also be used as a force apparatus to measure forces of receptor‐ligand interactions down to the single‐molecule level, acquire information about the mechanical properties of biological materials including cells, as well as to measure forces of protein folding/unfolding.
Microscopy, Scanning Tunneling
Authors: Ayres Virginia M. , Udpa Lalita 
Published: April 2006

Abstract
Scanning tunneling microscopy (STM) has the highest resolution of all scanning probe techniques, routinely producing atomic scale images. With such resolution, it is highly desirable to apply STM to investigations of molecular biology and medicine. The difficulty when considering the application of STM to molecular biology is that biological samples are nonconductive. It may be more accurate to describe biological samples as having both local and varying conductivities. These two issues will addressed in this review, and examples of conditions for the successful use of STM for biomedical imaging will be discussed. Successful applications of STM to significant research problems in biology and medicine will be presented.
Optical Tweezers
Authors: Schek Henry , Hunt Alan J. 
Published: April 2006

AbstractOptical tweezers fill an important niche in the arsenal of single molecule biophysical techniques, combining the ability to manipulate micron scale objects with the ability to measure piconewton forces and nanometer displacements. This article briefly reviews the history and theory of optical trapping, and introduces the basic principals for applying an optical tweezers device to measure force and displacement. Several seminal experiments utilizing optical tweezers are reviewed to illustrate the capabilities and limitations of optical trapping.
Pancreas, Artificial
Authors: Hovorka Roman 
Published: April 2006

AbstractIn the last two decades, the advancements in the field of continuous glucose sensors have stimulated the development of prototypes of a closed‐loop system based on combination of a continuous monitor, a control algorithm, and an insulin pump. This is denoted as an artificial electromechanical endocrine pancreas.The existing prototypes can be divided according the way they handle meal delivery into “fully closed‐loop” or “closed‐loop with meal announcement” systems. Depending on body interface, three major types of artificial pancreas are recognized, (i) the subcutaneous (sc) sensing and sc delivery (sc–sc) system, (ii) the iv sensing and intraperitoneal (ip) delivery (iv–ip) system, and (iii) the iv glucose sensing and iv insulin delivery (iv–iv) system.The description of the following prototypes and the work of the following research groups is reviewed: the Biostator, Shichiri’s group, Minimed–Medtronic, Roche Diagnostics, Adicol project, Institute for Diabetes Technology, and EVADIAC group. Human clinical studies are summarized.It is concluded that the lack of availability of a glucose monitor with adequate properties appears to hinder further progress and the development of a commercially viable system. The existing control algorithms need to be improved and subjected to rigorous clinical testing. The artificial pancreas is most likely to find its wider use in the supervised hospital environment, such as at the intensive care units. The application in home settings will most likely be gradual starting with a supervised system (by the treated subjects) and increasing its autonomous function following on from wider experience.