Medical prostheses

International Association of Medical Prosthesis Manufacturers (lAPM)... 

The use of bacterial cellulose in medical prosthesis is exciting, considering the perspectives of applications in cardiac bypass surgery and self-transplanted derivation vessels [23]. 

When a medical prosthesis such as a catheter, guide wire, angioplasty balloon, or stent is inserted to a blood vessel, external force is needed to advance the prosthesis into the right position. Ideally, the force used should be as low as possible to minimize surgeons ... 

The biomaterials which are used in medical or dental prostheses must not only exhibit structural stability and provide the desired function, but they must also perform over extended periods of time in the environment of the body. The latter is a very stringent requirement. The oral and other physiological environments are designed by nature to break down many organic substances. Also of importance is the requirement that materials used in the prosthesis not have a deleterious effect on body tissues. Most foreign (to the body) substances are somewhat toxic to human tissues in fact, few factors are more limiting in the medical prosthesis field than the biocompatibility problem. Some of these problems and the attempts to solve them are discussed in this volume. 

Titanium alloys generally show a combination of strength and biocompatibility which makes them suitable for medical devices (prosthesis, surgical instruments). The high strength Ti-6Al-7Nb alloy has several orthodontic applications. Only a limited number of alloys have the necessary combinations of properties needed for successful use in the human body. Titanium and its alloys, stainless steels and cobalt-chromium alloys are the workhorse alloys in the medical device industry. 

Even with this somewhat stricter definition, there is room for discretion. A sportsman who takes an occasional puff of a bronchodilator for exercise-induced asthma but is otherwise asymptomatic may be considered eligible by some. Individuals who have undergone surgery for a congenital condition and are in excellent health may or may not be suitable. Thus, an asymptomatic patient with a hip prosthesis who is taking no medication may be acceptable whereas an equally healthy individual with a prosthetic heart valve should be excluded from a study involving a cannula because of the risk, however remote, of endocarditis. Clearly, whatever definition of a healthy volunteer is used, sensible clinical judgement is still required. 

Yeast flocculation mechanism can be described as a phenomenon of adhesion to certain surfaces. The ability to adhere to surfaces and to form biofilm is the basis of the pathogenicity of Candida species. Pathogens adhere to mucous membranes and wounds, they stick to medical instruments and prosthesis, and thus contaminate surfaces in food processing facilities. The high mortality rate in disseminated fungal infections caused an increase in the amount of research on the molecular basis of the adhesive phenomena in Candida. This research discovered a considerable overlap in the molecular regulation of all forms of adhesive behavior. ... 

A significant contribution of Raman spectroscopy to the analytical characterization of biomedical issues has been made in the area of biomaterials, especially in the identification of biodegradation and deterioration [1, 2]. The general impact of Raman spectroscopy on the study of biomaterials has been described by this author in three recent review articles [3-5]. In this chapter, the topic of Raman characterization of biomaterials is revisited with particular emphasis placed on those biomaterials widely employed for load-bearing surfaces in artificial joints. Important recent case studies are presented to illustrate the power of the Raman technique to answer key questions of broad medical, scientific, and technological interest. The analytical and physical science lying behind the Raman effect is shown to contribute to the accumulation of a wealth of fundamental information about the medical and technical achievements of prosthesis makers. 

Medical Alerts (examples hearing aids, prosthesis, heart valves, eyeglasses, artificial hips) ... 

A consortium of 13 technical and medical partners works on different tasks to develop a complete system for a visual prosthesis (Fig. 25). The neural pros-theses comprises a unit to record and process ambiance light, an encoder that transforms visual information into a sequence of stimulation pulses, a micro-electromechanical system that is implanted into the eye for interfacing the retina and for generating the appropriate stimuli. 

Diamond-like carbon since its inception in 1962 has found applications in some very important areas. These applications include coatings used in scratch-resistant optics, razor blades, prosthesis in medical applications electron emission surfaces in electronics as an insulator material for copper heat sinks in semiconductors such as solar cells and sensors for visible to infrared radiations and as structural materials such as deuterated DLC film used for neutron storage in advanced research instrumentation. As technology matures the unique properties of DLC will find new and important applications. 

Interest in predicative testing extends not only to long periods of service but to relatively short time periods as well when biodegradability is concerned or in biocompatible systems in medical use whether it be in adhesion of bone or prosthesis or packaging is concerned, and in food additives when for example a species may be of consequence when present in the polymer and potentially extracted or present as a delicate flavor or color and absorbed by the maeromolecular system. 

American Medical Association as much as possible amorphous material ambulate ambulatory arm muscle circumference age-related macular degeneration acute megokaryoblastic leukemia acoustic myography acute myocardial infarction acute myelogenous leukemia agnogenic myeloid metaplasia acute myelomonoblastic leukemia amniocentesis acute monoblastic leukemia amputation ampule Austin-Moore prosthesis alternating motor rates acute mountain sickness amylase assisted mechanical ventilation... 

Developments related to medical implants, artificial organs, and prosthesis have improved the quality of life and increased the life expectancy of many individuals. 

Minneapolis, MN.) (b) Chitra tilting disc valve prosthesis with the occluder made of ultra high molecular weight polyethylene. (Courtesy of Sree Chitra Tirunal Institute for Medical Sciences and Technology, India.)... 

Bona, G., Rinaldi, S., and Vallana, F. 1997. Design characteristics of the BICARBON bileaflet heart valve prosthesis. In Surgery for Acquired Aortic Valve Disease. Piwnica, A. and Westaby, S. Eds., ISIS Medical Media, Oxford, pp. 392-396. 

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