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Telectronics
Telectronics Pty Ltd was an Australian company best known for its role in developing the pacemaker. It was located in Lane Cove, Sydney. In 1988 the business was acquired by Pacific Dunlop. and also However, legal claims resulting from the sale of faulty pacemaker electrode leads inherited by the company in acquisition of Cordis Corporation of Miami led to eventual sale of the assets of the company and Pacific Dunlop restructuring itself into Ansell. Development of the pacemaker Telectronics Pty Limited was incorporated in Sydney, Australia, in 1963"Telectronics and The History Of Pacemaking In Australia", Wickham G G, Jeffcoat KW, 1987 manuscript held by http://www.austehc.unimelb.edu.au. University Of Melbourne .(www.austehc.unimelb.edu.au.) by technician and initial financier Noel Gray and engineer Geoffrey Wickham initially designing and manufacturing industrial and scientific instruments but diversifying into medical electronics and commencing cardiac pacemaker research ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noel Gray
Noel Desmond Gray (26 December 1920 – November 1999) Senior design engineer at the Philips subsidiary Kriesler and medical student at the University of Sydney after War service in the Royal Australian Electrical and Mechanical Engineers. He formed the desire to start the Medical Device Industry at Med School and co-founded Telectronics Pty Ltd. Early life Noel Gray was born to Hilda Alice Gray on Boxing Day 1920 in Crookwell, New South Wales, Australia. Separated from his father Jo Gray, Hilda took him to grow up with her father at Middle View near Dalgety on the Snowy River. His grandfather brought him up. George Hedger was son of a man that newspaper reports said was the original inspiration for the Banjo Paterson poem "The Man from Snowy River". Noel and Hilda moved to Sydney and he attended a number of technical schools and at the Sydney Technical School passed the Intermediate Certificate He then went to worked in the radio industry culminating in a position at Kriesle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geoffrey Wickham
Geoffrey Gordon Wickham (born 28 October 1933) is one of the pioneers of cardiac pacemaking. He was born in 1933 in Camperdown, Victoria, Australia to dairy farmer parents. In 1963 he co-founded the medical instruments company Telectronics Pty Ltd in Sydney, and served as the company's Chief Engineer from 1963 to 1970 and Technical Director from 1963 to 1978. He was elected an Honorary Life Governor of Royal Prince Alfred Hospital, Sydney in 1982, and was appointed Officer of the Order of Australia in June 2000 "for service to the design of medical equipment, particularly in the development of the implantable cardiac pacemaker". Wickham had no formal engineering training, finishing High School at Year 8 to commence work as a radio and electrical repairman. At age 21 he passed the Year 12 examinations by night study at the South Australian School of Mines and Industries, while working as a technician at the Department of Supply, Long Range Weapons Establishment in South Austr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artificial Pacemaker
An artificial cardiac pacemaker (or artificial pacemaker, so as not to be confused with the natural cardiac pacemaker) or pacemaker is a medical device that generates electrical impulses delivered by electrodes to the chambers of the heart either the upper atria, or lower ventricles to cause the targeted chambers to contract and pump blood. By doing so, the pacemaker regulates the function of the electrical conduction system of the heart. The primary purpose of a pacemaker is to maintain an adequate heart rate, either because the heart's natural pacemaker is not fast enough, or because there is a block in the heart's electrical conduction system. Modern pacemakers are externally programmable and allow a cardiologist, particularly a cardiac electrophysiologist, to select the optimal pacing modes for individual patients. Most pacemakers are on demand, in which the stimulation of the heart is based on the dynamic demand of the circulatory system. Others send out a fixed rate of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Dunlop
Pacific Dunlop was a highly diversified Australian conglomerate company that operated in, among other things, the Automotive, textile, electronics and biotechnology industries. Products commercialised included tires, car batteries, cables, clothing, electronics, bedding, condoms. Facing financial difficulties, it rapidly spun off and sold its non-core assets before renaming itself Ansell in 2002. In 2006, it sold its tyre making business to Goodyear to focus on the manufacturing of latex products. History Pacific Dunlop has its roots in the Irish Dunlop Pneumatic Tyre Company, which established the Dunlop Pneumatic Tyre Company of Australasia in 1893, which included a local finishing factory and office in Melbourne to supply the market with bicycle tyres. In 1899 downturn in cycling's popularity and speculation from the parent company led to the sell-off of Dunlop's Australasian and North American operations, and the Dunlop Pneumatic Tyre Company of Australasia was floated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendrites
Dendrites (from Greek δένδρον ''déndron'', "tree"), also dendrons, are branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. Electrical stimulation is transmitted onto dendrites by upstream neurons (usually via their axons) via synapses which are located at various points throughout the dendritic tree. Dendrites play a critical role in integrating these synaptic inputs and in determining the extent to which action potentials are produced by the neuron. Dendritic arborization, also known as dendritic branching, is a multi-step biological process by which neurons form new dendritic trees and branches to create new synapses. The morphology of dendrites such as branch density and grouping patterns are highly correlated to the function of the neuron. Malformation of dendrites is also tightly correlated to impaired nervous syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal
A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically ductile (can be drawn into wires) and malleable (they can be hammered into thin sheets). These properties are the result of the ''metallic bond'' between the atoms or molecules of the metal. A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride. In physics, a metal is generally regarded as any substance capable of conducting electricity at a temperature of absolute zero. Many elements and compounds that are not normally classified as metals become metallic under high pressures. For example, the nonmetal iodine gradually becomes a metal at a pressure of between 40 and 170 thousand times atmospheric pressure. Equally, some materials regarded as metals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analysis
Analysis ( : analyses) is the process of breaking a complex topic or substance into smaller parts in order to gain a better understanding of it. The technique has been applied in the study of mathematics and logic since before Aristotle (384–322 B.C.), though ''analysis'' as a formal concept is a relatively recent development. The word comes from the Ancient Greek ἀνάλυσις (''analysis'', "a breaking-up" or "an untying;" from ''ana-'' "up, throughout" and ''lysis'' "a loosening"). From it also comes the word's plural, ''analyses''. As a formal concept, the method has variously been ascribed to Alhazen, René Descartes (''Discourse on the Method''), and Galileo Galilei. It has also been ascribed to Isaac Newton, in the form of a practical method of physical discovery (which he did not name). The converse of analysis is synthesis: putting the pieces back together again in new or different whole. Applications Science The field of chemistry uses analysis in thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dissection
Dissection (from Latin ' "to cut to pieces"; also called anatomization) is the dismembering of the body of a deceased animal or plant to study its anatomical structure. Autopsy is used in pathology and forensic medicine to determine the cause of death in humans. Less extensive dissection of plants and smaller animals preserved in a formaldehyde solution is typically carried out or demonstrated in biology and natural science classes in middle school and high school, while extensive dissections of cadavers of adults and children, both fresh and preserved are carried out by medical students in medical schools as a part of the teaching in subjects such as anatomy, pathology and forensic medicine. Consequently, dissection is typically conducted in a morgue or in an anatomy lab. Dissection has been used for centuries to explore anatomy. Objections to the use of cadavers have led to the use of alternatives including virtual dissection of computer models. Overview Plant and animal b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanium Dioxide
Titanium dioxide, also known as titanium(IV) oxide or titania , is the inorganic compound with the chemical formula . When used as a pigment, it is called titanium white, Pigment White 6 (PW6), or CI 77891. It is a white solid that is insoluble to water, although mineral forms can appear black. As a pigment, it has a wide range of applications, including paint, sunscreen, and food coloring. When used as a food coloring, it has E number E171. World production in 2014 exceeded 9 million tonnes. It has been estimated that titanium dioxide is used in two-thirds of all pigments, and pigments based on the oxide have been valued at a price of $13.2 billion. Structure In all three of its main dioxides, titanium exhibits octahedral geometry, being bonded to six oxide anions. The oxides in turn are bonded to three Ti centers. The overall crystal structure of rutile is tetragonal in symmetry whereas anatase and brookite are orthorhombic. The oxygen substructures are all slight distort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Electronics
Digital electronics is a field of electronics involving the study of digital signals and the engineering of devices that use or produce them. This is in contrast to analog electronics and analog signals. Digital electronic circuits are usually made from large assemblies of logic gates, often packaged in integrated circuits. Complex devices may have simple electronic representations of Boolean logic functions. History The binary number system was refined by Gottfried Wilhelm Leibniz (published in 1705) and he also established that by using the binary system, the principles of arithmetic and logic could be joined. Digital logic as we know it was the brain-child of George Boole in the mid 19th century. In an 1886 letter, Charles Sanders Peirce described how logical operations could be carried out by electrical switching circuits.Peirce, C. S., "Letter, Peirce to A. Marquand", dated 1886, '' Writings of Charles S. Peirce'', v. 5, 1993, pp. 541–3. GooglPreview See Burks, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transvenous Pacing
Transvenous cardiac pacing (TVP), also called endocardial pacing, is a potentially life-saving intervention used primarily to correct profound bradycardia. It can be used to treat symptomatic bradycardias that do not respond to transcutaneous pacing or to drug therapy. Transvenous pacing is achieved by threading a pacing electrode through a vein into the right atrium, right ventricle, or both. This means of pacing the heart is not as popular as other means of pacing (see transcutaneous pacing, implanted pacemaker, epicardial pacing) because it is a temporary solution to pace the heart and yet involves a similar level of risk of bleeding as a more permanent solution like placing an implanted pacemaker. For patients who present in an emergency setting with symptomatic bradycardias, usually drugs like atropine or sympathomimetic drugs (epinephrine or dopamine) can be used to increase the heart rate to an adequate level until the underlying cause of the bradycardia can be isolate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Impedance
In electrical engineering, impedance is the opposition to alternating current presented by the combined effect of resistance and reactance in a circuit. Quantitatively, the impedance of a two-terminal circuit element is the ratio of the complex representation of the sinusoidal voltage between its terminals, to the complex representation of the current flowing through it. In general, it depends upon the frequency of the sinusoidal voltage. Impedance extends the concept of resistance to alternating current (AC) circuits, and possesses both magnitude and phase, unlike resistance, which has only magnitude. Impedance can be represented as a complex number, with the same units as resistance, for which the SI unit is the ohm (). Its symbol is usually , and it may be represented by writing its magnitude and phase in the polar form . However, Cartesian complex number representation is often more powerful for circuit analysis purposes. The notion of impedance is useful for perf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
