History of Electrocardiography Machine Essay Example for Free

History of Electrocardiography Machine Essay History of electrocardiography prevails over two centuries as an intellectual exercise as the process of inventing an electrocardiogram started with the Galvani’s idea of animal electricity. In 1842 this idea was further reinforced by Italian physicist Carlo Matteucci who illustrated by his experiments that electric current could be quantified from inactive heart muscle. German physiologist Emil Dubois-Reymond further explored this phenomenon and confirmed Carlo Matteucci’s conclusion and labeled this changing current in the resting muscle as â€Å"action potential†. He further developed a device that could deliver stimulation pulses to the muscles and was capable of computing discharge current of muscles at short intervals. In 1856 Rudolph von Koelliker and Heinrich Muller recorded an â€Å"action potentialâ€Å"on the spotaneous beating heart. But the major development came in 1872 when French physicist Gabriel Lippmann introduced a capillary electrometer. This capillary electrometer was based on the principle of â€Å"polarization† and â€Å"surface tension†. Structurally it was a slender glass tube with mercury-sulphuric acid base. The mercury meniscus stirred with the influx of electrical potential and was observable by a microscope. In 1893, Willem Einthoven who is considered as the inventor of modern electric cardiogram and its various principles used the term electrocardiogram at a conference of the Dutch Medical Association. But major development occurred during the three years staring from 1901 when Einthoven dissatisfied with capillary electrometer and it slow response, designed a string galvanometer. This galvanometer contained a string eletromagnet to produce a magnetic flux, two piece poles, a quartz string between the two piece poles, peepholes in the two piece poles to observe the position of string. It further contained a lamp and timing systen to examine the shadow of string at different time intervals. The weight of this whole apparatus was about 600 pounds. He further modified the string galvanometer to invent a more effective electrocardiograms. However in 1902, Einthoven brought out the first electrocardiogram that was recorded on his string galvanometer. This was a giant’s leap in the history of bio-medical. In order to produce string galvanometer on commercial level, Einthoven discussed the possibilities with Horace Darwin of Cambridge Scientific Instruments Company of London. So this event made the electrocardiogram to come out of experimentation and to be used in medical profession. Einthoven, in 1906, circulated the first presentation electrocardiograms recorded with a string galvanometer. These electrocardiograms included the specimen of left and right ventricular and atrial, atrial flutter, ventricular premature beats etc. In 1910, Horatio Williams who was professor at Cornell University Medical College, New York issued electrocardiograms of patient that manifest atrial and ventricular ectopics, ventricular hypertrophy, atrial fibrillation and ventricular fibrillation that were recorded in hospital using a complex system of cables. This was first large-scale use of electrocardiograms in the hospitals. With the advent and introduction of vacuum tubes, the electric galvanometer was further modified and improved. In 1926, Ernestine and Levine used these vacuum tubes to produce enlarged images. Cathode rays tube further helped to produce portable electrocardiograms. Today electrocardiograms works on the same principles that were devised Einthoven in the first decade of 20th century. References Burchell HB. A centennial note on Waller and the first human electrocardiogram. Am J Cardiol 1987; 59:979-983 Burch, G.E. A History of Electrocardiography. Chicago. Year Book Medical. 1964. Burnett J. The origins of the electrocardiograph as a clinical instrument. Medical History Supplement 5: 1985, 53-76. Published as a monograph. The emergence of modern cardiology. Bynum WF, Lawrence C, Nutton V, eds. Wellcome Institute for the History of Medicine:1985. Fye WB. A history of the origin, evolution, and impact of electrocardiography. Am J Cardiol 1994;73:937-949 Plonsey, R. Bioelectric Phenomenon. New York. McGraw-Hill. 1972.

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Why I should be the Supreme Ruler of the Universe   Ã‚  Ã‚  Ã‚  Ã‚  In these five paragraphs, I will be discussing why I should be the supreme rule of the universe. I will explain my strong points in ruling such as my ability to converse with people on a down to earth basis. My ability to help the people of the world by giving them not just what they want, but what they need. Also I will be able to save the world by setting stricter laws prevent damage to the earth. To get deeper into the subject everyone will have a say in what I do to help the world and it's inhabitants. My people skills will help my ability to rule because then I would be able to talk to my people of the world by discussing key topics like the earth and it's atmosphere. My way with people will also help to show how I treat my co-workers and fellow countrymen. I will really test my people skills when I go to my other countries and discuss trade and life in that part of the world. I would really want show the people that I am not afraid of what the world throws at. I am afraid of only one thing and that's whether the people of earth are content in how I am running it. Hopefully I will show that my skills are adequate and that I am capable of putting them to work in a useful way. In some way I believe that you will all make the right decision in placing me as supreme ruler of the universe. I hope all the people of earth will be satisfied with what I give them and what show them. Surely I will give them what they want but I do hope I will be able to give them what they need. That being, that all will have food shelter and adequate money resources. There will be no ghettos or gangs or drugs. I will give the world the chance to live in a happy place where there is no violence or drugs because that is how I see the world should and will be. Everybody will get his or her share because everyone is equal. Not one person should feel that they are not getting their piece of the pie because I hope to make sure that no one is left out.

Experience of Life

Have you ever thought how much someone can grow and learn through the experiences? There are many factors in how people can change their personality; their way of thinking and every day grow more as a person. Life is too complex to understand, it is better to live and enjoy each day to the fullest that it is where you learns more. In my opinion, I believe in what my mother says, â€Å"Everyone must go through their own experiences and learn from their own mistakes†. I personally have changed a lot as a person in the past two years by different life experience like my graduation in college, starting a new job and moving to another country.My first impact when I understood that my life was changing and I had to go through new roads was my graduation day. I was with my toga and cap in a huge classroom with more than a hundred students, all seated waiting for our bachelor’s degree. Upon hearing my name and having to climb onto the stage to receive my degree was the moment w hen I realized that I was no longer a child and I became a woman with a degree from preschool teacher. The shock of knowing that my life was going to start to be different and I will start a new life as an adult and with a real job frame my life.The jump from being a student to becoming a professional is awesome, I am very proud of my achievements but on the other hand, I went into a panic at not knowing what was coming next. I think that in that moment was a huge change in my life that made me mature tremendously. After I understand that my life had changed, I started my adventure of living the life that I always dreamed, to be a teacher. The time of being a head teacher had arrived. During my two years of working I was a head teacher of Nursery.The experience I had during those two years was amazing; it's incredible how children transmit you peace, happiness and that innocence that captures the heart of everyone. However, some of my biggest challenges during my years of work were dealing with parents. For example, in my first year of teaching one of my students father ordered an appointment with the director and me to see if I met his expectations as a teacher of his daughter. At first, I will not deny, I felt insulted because how could a parent knowing that â€Å"El Jefferson† is one of the best schools in Caracas and he wanted to see if her daughter's teacher was professional†. That experience made me grow and understand each situation and fear that parents maybe can feel having to leave their children in a school when they have only 3 years old. At the end of the meeting the father apologized to me and congratulated me of my professionalism and the way that I took the meeting. I felt proud of myself and I gave him what he needs confidence and security. Each experience has made me grow in different ways and I really appreciate. Likewise, after having completed my two years of work experience in which I enjoy to the fullest.I started to go th rough some of the biggest changes in my life, moving to a new country. One of my life goals is to do a master of Special Education, so I decided to do this master in New York City. From the moment I stepped on the United States I realized that my life was changing 360 degrees. I was leaving my family, my friends, my life in Venezuela and I was faced with something new and different: different language, different culture, new friends, new place to live, etc. I can say this has been one of the strongest changes in my life that made e grow without anesthesia in too little time. Today I live alone, I cook, I do my laundry and I managed all my expenses. This is the first time that I am living alone and having my independence. I can totally say this is a unique and incredible experience. This opportunity that my parents are offering me has helped me to understand how difficult could be the life and if you dream for something you have to fight for it. For example, when I was at school or in college my mother was always reminding me to study or whatever, does not mean that I did not, but it is a typical habit of mothers.Now that I am here studying to start a master in NYC, all the responsibility of homework, studies, etc. it is totally on me. For anyone, this kind of life experience makes us grow up enormously and I appreciate every day in life than my parents could give me, because that is being changed me more and more as a person. In conclusion, it is difficult to write on paper all those experiences, which I have gone through and have changed me as a person. Each day that passes everyone live things that mark us forever, sometimes they are more noticeable than others. As my grandmother â€Å"People never stop learning no matter how old they are†.

War of 1812 - Causes

Having won its independence in 1783, the United States soon found itself a minor power without the protection of the British flag. With the security of the Royal Navy removed, American shipping soon began falling prey to privateers from Revolutionary France and the Barbary pirates. These threats were met during the undeclared Quasi-War with France (1798-1800) and First Barbary War (1801-1805). Despite success in these minor conflicts, American merchant ships continued to be harassed by both the British and the French. Engaged in a life-or-death struggle in Europe the two nations actively sought to prevent the Americans from trading with their enemy. In addition, as it depended upon the Royal Navy for military success, the British followed a policy of impressment to meet its growing manpower needs. This saw British warships stop American merchant vessels at sea and remove American sailors from their ships for service in the fleet. Though angered by the actions of Britain and France, t he United States lacked the military power to halt these transgressions. The Royal Navy Impressment The largest navy in the world, the Royal Navy was actively campaigning in Europe by blockading French ports as well as maintaining a military presence across the vast British Empire. This saw the size of the fleet grow to over 170 ships of the line and required in excess of 140,000 men. While volunteer enlistments generally met the services manpower needs during peacetime, the expansion of the fleet during times of conflict required the employment of other methods to sufficiently crew its vessels. To provide enough sailors, the Royal Navy was permitted a follow a policy of impressment which allowed it to draft into immediate service any able-bodied, male British subject. Often captains would send press gangs to round up recruits from pubs and brothels in British ports or from British merchant ships. The long arm of impressment also reached onto the decks of neutral commercial vessels, including those of the United States. British warships made a frequent habit of stopping neutral shi pping to inspect crew lists and remove British sailors for military service. Though the law required impressed recruits to be British citizens, this status was loosely interpreted. Many American sailors had been born in Britain and became naturalized American citizens. Despite possession of citizenship certificates, this naturalized status was often not recognized by the British and many American sailors were seized under the simple criterion of Once an Englishman, always an Englishman. Between 1803 and 1812, approximately 5,000-9,000 American sailors were forced into the Royal Navy with as many as three-quarters being legitimate American citizens. Heightening the tensions  was the practice of the Royal Navy stationing vessels off American ports with orders to search ships for contraband and men who could be impressed. These searches frequently took place in American territorial waters. Though the American government repeatedly protested the practice, British Foreign Secretary Lord Harrowby contemptuously wrote in 1804, The pretention advanced by Mr. [Secre tary of State James] Madison that the American flag should protect every individual on board of a merchant ship is too extravagant to require any serious refutation. The Chesapeake-Leopard Affair Three years later, the impressment issue resulted in a serious incident between the two nations. In the spring of 1807, several sailors deserted from HMS Melampus (36 guns) while the ship was at Norfolk, VA. Three of the deserters then enlisted aboard the frigate USS Chesapeake (38) which was then fitting out for a patrol in the Mediterranean. Upon learning of this, the British consul at Norfolk demanded that Captain Stephen Decatur, commanding the navy yard at Gosport, return the men. This was refused as was a request to Madison who believed the three men to be Americans. Subsequent affidavits later confirmed this, and the men claimed they had been impressed. The tensions were heightened when rumors circulated that other British deserters were part of Chesapeakes crew. Learning of this, Vice Admiral George C. Berkeley, commanding the North American station, instructed any British warship that encountered Chesapeake to stop it and search for deserters from HMS  Belleisle (74), HMSà ‚  Bellona (74), HMS  Triumph (74), HMS  Chichester (70), HMS  Halifax (24), and HMS  Zenobia (10). On June 21, 1807, HMS Leopard (50) hailed Chesapeake shortly after it cleared the Virginia Capes. Sending a Lieutenant John Meade as messenger to the American ship, Captain Salusbury Humphreys demanded that the frigate be searched for deserters. This request was flatly refused by Commodore James Barron who ordered the to ship be prepared for battle. As the ship possessed a green crew and the decks were cluttered with supplies for an extended cruise, this procedure moved slowly. After several minutes of shouted conversation between Humphreys and Barron, Leopard fired a warning shot, then a full broadside into the unready American ship. Unable to return fire, Barron struck his colors with three men dead and eighteen wounded. Refusing the surrender, Humphreys sent across a boarding party which removed the three men as well as Jenkin Ratford who had deserted from Halifax. Taken to Halifax, Nova Scotia, Ratford was later hung on August 31 while the other three were sentenced to 500 lashes each (this was later commuted). In the wake of the Chesapeake-Leopard Affair an outraged American public called for war and President Thomas Jefferson to defend the nations honor. Pursuing a diplomatic course instead, Jefferson closed American waters to British warships, secured the release of the three seamen, and demanded an end to impressment. While the British did pay compensation for the incident, the practice of impressment continued unabated. On May 16, 1811, USS President (58) engaged HMS Little Belt (20) in what is sometimes considered a retaliatory attack for the Chesapeake-Leopard Affair.  The incident followed an encounter between HMS Guerriere (38) and USS Spitfire (3) off Sandy Hook that resulted in an American sailor being impressed. Encountering Little Belt near the Virginia Capes, Commodore John Rodgers gave chase in belief the British vessel was Guerriere. After an extended pursuit, the two vessels exchanged fire around 10:15 PM. Following the engagement, both sides repeatedly argued that the ot her had fired first. Issues of Neutral Trade While the impressment issue caused problems, tensions were further heightened due to Britain and Frances behavior regarding neutral trade. Having effectively conquered Europe but lacking the naval strength to invade Britain, Napoleon sought to cripple the island nation economically. To this end he issued the Berlin Decree in November 1806 and instituted the Continental System which made all trade, neutral or otherwise, with Britain illegal. In response, London issued the Orders in Council on November 11, 1807, which closed European ports to trade and barred foreign ships from entering them unless they first called at a British port and paid customs duties. To enforce this, the Royal Navy tightened its blockade of the Continent. Not to be outdone, Napoleon responded with his Milan Decree a month later which stipulated that any ship that followed the British rules would be considered British property and seized. As a result, American shipping became prey for both sides. Riding the wave of outrage that followed the Chesapeake-Leopard Affair, Jefferson implemented the Embargo Act of 1807 on December 25. This act effectively ended American foreign trade by prohibiting American ships from calling at overseas ports. Though drastic, Jefferson hoped to end the threat to American vessels by removing them from the oceans while depriving Britain and France of American goods. The act failed to achieve his goal of pressuring the European superpowers and instead severely crippled the American economy. By December 1809, it was replaced with the Non-Intercourse Act which allowed overseas trade, but not with Britain and France. This still failed to change their policies. A final revision was issued in 1810 which removed all embargoes, but stated that if one nation stopped attacks on American ships, the United States would begin an embargo against the other. Accepting this offer, Napoleon promised Madison, now president, that neutral rights would honored. This agreement further angered the British despite the fact that the French reneged and continued seizing neutral ships. War Hawks Expansion in the West In the years following the American Revolution, settlers pushed west across the Appalachians to form new settlements. With the creation of the Northwest Territory in 1787, increasing numbers moved to the present-day states of Ohio and Indiana pressuring the Native Americans in those areas to move. Early resistance to white settlement led to conflicts and in 1794 an American army defeated the Western Confederacy at the Battle of Fallen Timbers. Over the next fifteen years, government agents such Governor William Henry Harrison negotiated various treaties and land deals to push the Native Americans farther west. These actions were opposed by several Native American leaders, including the Shawnee chief Tecumseh. Working to build a confederacy to oppose the Americans, he accepted aid from the British in Canada and promised an alliance should war occur. Seeking to break the confederacy before it could fully form, Harrison defeated Tecumsehs brother, Tenskwatawa, at the Battle of Tippecano e on November 7, 1811. During this period, settlement on the frontier faced a constant threat of Native American raids. Many believed these were encouraged and supplied by the British in Canada. The actions of the Native Americans worked to advance British goals in the region which called for the creation of a neutral Native American state that would serve as a buffer between Canada and the United States. As a result, resentment and dislike of the British, further fueled by events at sea, burned brightly in the west where a new group of politicians known as the War Hawks began to emerge. Nationalistic in spirit, they desired war with Britain to end the attacks, restore the nations honor, and possibly to expel the British from Canada. The leading light of the War Hawks was Henry Clay of Kentucky, who was elected to the House of Representatives in 1810. Having already served two brief terms in the Senate, he was immediately elected Speaker of the House and transformed the position into one of power. In Congr ess, Clay and the War Hawk agenda were supported by individuals such as John C. Calhoun (South Carolina), Richard Mentor Johnson (Kentucky), Felix Grundy (Tennessee), and George Troup (Georgia). With Clay guiding debate, he ensured that Congress moved down the road to war. Too Little, Too Late Seizing upon the issues of impressment, Native American attacks, and the seizure of American ships, Clay and his cohorts clamored for war in early 1812, despite the countrys lack of military preparedness. Though believing that the capture of Canada would be simple task, efforts were made to expand the army but without great success. In London, the government of King George III was largely preoccupied with Napoleons invasion of Russia. Though the American military was weak, the British did not wish to fight a war in North America in addition to the larger conflict in Europe. As a result, Parliament began debating repealing the Orders in Council and normalizing trade relations with the United States. This culminated in their suspension on June 16 and removal on June 23. Unaware of developments in London due to the slowness of communication, Clay led the debate for war in Washington. It was a reluctant action and the nation failed to unite in a single call for war. In some places, people even debated who to fight: Britain or France. On June 1, Madison submitted his war message, which focused on maritime grievances, to Congress. Three days later, the House voted for war, 79 to 49. Debate in the Senate was more extensive with efforts made to limit the scope of the conflict or delay a decision. These failed and on June 17, the Senate reluctantly voted 19 to 13 for war. The closest war vote in the history of country, Madison signed the declaration the next day. Summing up the debate seventy-five years later, Henry Adams wrote, Many nations go to war in pure gayety of heart, but perhaps the United States were the first to force themselves into a war they dreaded, in hope that the war itself might create the spirit they lacked.