ECG and Pulse Oximetry: History and Types

ECG and Pulse Oximetry: History and Types In this chapter, we will discuss the history of ECG and pulse oximetry, the timeline and variations through time of the concepts used. We all also discuss the types of pulse oximetry and the electronics used with their requirements. 1.1 History of ECG The history of ECG is very wide, dating back to the 1600 with William Gilbert (that introduced the electrica concept for objects holding static electricity) (1).The most important founders of the electrocardiogram concept were Emil Reymond and Willem Einthoven. In 1843, Emil Reymond was the founder of the electrocardiograph concept by using a galvanometer to state that muscular contraction has action potentials. He also identified the types of waves by using the P, Q, R, and S waves. His studies inspired many physicians to continue and develop his work further. The evolution of concepts continued until the discovery of P, Q, R, S and T waves by Willem Einthoven in 1895. Einthoven also invented a modified galvanometer and used in for electrocardiogram recording. As a reward for his work, he won a Noble price in 1924 for inventing the electrocardiograph (1). As stated before, the history of ECG is very wide, therefore we will limit the observation to the movement done between 1843 and 1942 as shown in the following table: Table 1: ECG Timeline Year Scientist Concept 1842 Carlo Matteucci heart beat is accompanied by electric current 1843 Emil Dubois-Reymond Muscular contraction is accompanied by action potential. Test carlos concept on animals successfully 1856 Koelliker , Muller Record of the action potential concept 1869 Alexander Muirhead Might have recorded a human electrocardiogram 1872 Gabriel Lippmann Capillary Electrometer invented 1876 Marey EJ Electrical activity of animal recorded by the electrometer 1878 John Sanderson , Frederick Page Electrical current of the heart is recorded Divide into two phases (later known as QRS and T) 1887 Augustus Waller First human electrocardiogram is published 1890 GJ Burch Arithmetic correction of the electrometer 1891 William Bayliss , Edward Starling Capillary electrometer improved Discovery of deflections (later known as P,QRS,T) and delay (later know as PR interval) 1893 Willem Einthoven The term electrocardiogram introduced 1895 Deflections P,Q,R,S and T distinguished 1897 Clement Ader Galvanometer invented( Amplification system for the lines of telegraph ) 1901 Willem Einthoven Galvanometer modified for ECG use 1902 ECG records using galvanometer published 1903 Commercial production of galvanometer discussed 1905 Telecardigram invented (transmission of ECG signal by telephone) 1906 Normal and abnormal ECG record published Introduction of the U wave 1908 Edward Schafer First purchase of Einthovens galvanometer 1910 Walter James, Horatio Williams Electrocardiography reviewed for the first time in America 1911 Thomas Lewis Publication of a book about heart beat mechanism 1912 Willem Einthoven Description of the Einthoven triangle (formed for the leads) 1920 Hubert Mann Derivation of mono-cardiogram (later known as vector-cardiogram) 1924 Willem Einthoven Nobel price won for the electrocardiograph invention 1928 Ernstine, Levine Introduction of vacuum-tubes for ECG amplification Frank Sanborn First portable ECG invented 1932 Charles Wolferth and Francis Wood Description of the chest leads use in the coronary occlusion 1938 American heart and cardiac British association Standard positions of chest leads defined and added (V1 to V6) 1942 Emanuel Goldberge Addition of aVR, aVL and AVF to previous model Final ECG model used today 1.2: History of pulse oximetry The revolutionary paper by Comroe and Botelho was the founder movement that stated the need for a better method for the detection of hypoxaemia later known as pulse oximetry. The paper clearly underlined the unreliability of the cyanosis method currently used for the detection of arterial hypoxaemia. This was done by showing that if the oxygen saturation is reduced to 75% the cyanosis could not be detected. Another paper written by Lundsgaard and Van Slyke enhanced the movement. The paper showed the factors that enhance the cyanosis such as 5mg reduced hemoglobin per 100 ml capillary blood. The paper also showed that the subject, environmental factors and the tester affects greatly the detection of cyanosis. As a result, many type of instrumentation were developed to detect the presence of hypoxaemia. However, these devices were inaccurate due to the inability to detect the difference between arterial oxygen saturation and the arterial venous and capillary blood. This separation rema ins a problem until the microprocessor era where the separation was finally realizable. Pulse oximetry started as a simple monitoring technique and evolved through 15 years to become mandatory with every anaesthetic. It has the ability to detect the difference between arterial blood and venous capillary blood due to the pulsatile characteristics of the arterial blood and the smooth flowing of the capillary blood. The pulse oximetry became mandatory in anaesthetic due to the many characteristic such as: having a safety monitor showing the amount of oxygenation in the patient and the circulation of the blood having an non-invasive nature having no morbidity low running cost low capital cost On the other hand, pulse oximetry has been imposed to some unjust criticism as in the case of any new technology. As a result, pulse oximetry has been accused of morbidity despite being a non-invasive technique; it has been accused of causing tissue damage to the tissues adjacent to the probe. As a result, the Medical Devices Agency in England issued a safety action bulletin that contained a historical background, mode of operation, calibration problems, the characteristics of clinical uses and the technique limitation. 1.2.1 Hewlett-Packard ear oximeter Johann Heinrich Lambert was the founder of the correlation that exists between the absorbant and the amount of light absorbed in 1760. His ideas were developed later on by August Beer in 1851. However, the first real adoption of pulse oximetry was the ear oximeter founded by Hewlett-Packard. The concept used in this oximeter is based on an incandescent source combined with narrowband interference filters to transmit eight different wavelengths. Fiberoptics are used to lead the transmitted light from pinna to the detector. The calculation of the arterial oxygen saturation is based on the eight wavelengths absorption. In order to approximate the arterial saturation .this calculation is based on an approximation of overall absorption. The ear is heated causing vasodilation and the capillary blow flow to increase. That phenomenon leads to the approximation of the arterial saturation. The main problem of the device was the constant need for calibration due to the large and hard to handle probe-head. However, this technique was the only technique that allows continuous measurement of oxygen saturation; therefore this technique was the founder of pulse oximetry 1.2.2 Prototype pulse oximeter The founder configuration of pulse oximeter or the prototype used a light source and two bundles of fibers. The light source is made of halogen incandescent lamp to transmit the broad band energy to a fingertip probe. This transmission was done using a glass fiber bundle. Another bundle of fibers were used to return the transmitted energy to the apparatus. This returning energy is divided into two paths at the apparatus: one passing through a 650nm centered filter interface having a narrow bandwidth, and the second path passing through an 805 nm centered filter centered, that point is isopiestic hemoglobin. Then, a semiconductor sensor is used to detect the appropriate energy at the wavelengths passed through each filter. Finally, an analogue calculation is used to find the appropriate value of the oxygen saturation. This is clearly shown in the figure bellow. This primary prototype had many disadvantages such as: Having a heavy probe Having an hard to manage Fiberoptics cable Having an inaccurate filters letting some undesired wavelengths to pass through the tissues of the fingers Having a biohazard on the finger, in some cases the finger could burn Not fully respecting the beer-Lambert law Insensitivity with low pulse pressure Having a tendency to change in the analogue electronics part 1.2.3 Traditional pulse oximeter The current pulse oximeter uses light emitting diodes with a semiconductor photo detector to generate two wavelengths of 660 nm and 940 nm. Therefore this design provides a small and efficient probe to be attached to the ear or the finger and a small cable to connect the probe and the main unit. However, the pulse oximeter used with a magnetic resonance scanner has a different design. The main unit contains all the electronic components and optical fibers are used to transmit the light energy to and from the patient 1.2.4 Complete history of pulse oximetry BeerLambert law in 1851 Discovery of oxygen carrier in blood as a form of pigment by Georg Gabriel Stokes in 1864 Purification of the pigment and naming it hemoglobin by Felix Hoppe in 1864 Detailed study of the reflection spectra of the hemoglobin and the finger by Karl von Veirordt in 1876 Detailed study of the absorption spectra by Carl Gustav Hufner in 188790 Measure of the oxygen saturation in fish using spectroscopy by August Krough and I Leicht in 1919 Study of the light transmitted throughout human tissues using quantitative spectrophotometry by Ludwig Nicolai in 1931 Measurement of the oxygen saturation of blood through laboratory tubes Kurt Kramer in 1934 Measurement of the spectrum of concentrated hemolysed and non-hemolysed blood by David Drabkin and James Harold Austin in 1935 Continuous monitoring of oxygenation is achieved by passing red and infrared light throughout the finger web by JR Squires in 1940. This was done by creating bloodless area of calibration by compression of tissues Revolutionary change in the concept of oximeter leading to the development of the Millikan oximeter by Glen Alan Millikan in 1940-42 Creation of Woods ear oximeter by Earl Wood in 194850 Ability to differentiate between hemoglobin, carboxyhemoglobin and methemoglobin by the creation of CO-oximeter in 1960 Creation of the ear oximeter having eight wavelengths by Robert Shaw in 1964 Marketing of the newly created ear oximeter by Hewlett-Packard in 1970 Separation of the arteries absorption from the tissues absorption using the pulsatile nature of the absorption signal by Takuo Aoyagi in 1971 Development of prototype pulse oximeter containing luminous light source , filters and analogue electronics by Aoyagi in 1974 Commercialization of the pulse oximeter in 1975 Chapter II: Pulse Oximetry Characteristics The pulse oximeter separates the variation of oxygenation absorbance of the human boundary. The pulse oximeter uses the reflection from the skin and tissues or the transmission through the human boundary to perform spectrophotometry. The most common used technique is the transmission technique, but the reflection technique is also used in intrapartum monitoring. 2.1 Transmission pulse oximetry The human parts that must be chosen as extremity are the earlobe, toe, noise or typically the finger. The chosen part should have a short optical path length to have a translucent nature at the wavelengths used. The wavelengths used should have the range of 600 nm to 1300 nm and in the same range of the absorption spectrum due to the fact that each spices of hemoglobin have a unique absorption as shown in the figure bellow. As a result from the formulas we can show that the minimum number of used wavelengths should be greater or equal to the number of unknowns. As a result the commonly used pulse oximetry uses two wavelengths for the two unknowns oxygenated hemoglobin and deoxygenated hemoglobin. In addition, the wavelengths used must be monochromatic and have a low cost. In the design, a sensitive detector must be used to prevent high levels energy that causes tissue damage from passing through. Thus, there is a need to separate the saturation value for arterial hemoglobin. In order to separate the saturation, computing power is used for arterial hemoglobin saturation extraction. In addition to that, spectrophotometry requires the use of a laser due to the requirement of a single wavelength/color source as energy source. Therefore two lasers are used each having a different wavelength in order to transmit the energy to the patient boundary using optical fibers. Due to the presence of the laser, the pulse oximetry will have a high cost, a fragile nature and requires safety implications. However, the fiber optic cables were rejected in the later designs after the discovery of the possibility of the use of LED as an energy source. As a result, the overheating of the tissues problem was removed and the narrowband filters were removed from the design thus reducing the cost and fragility of the design. In addition, the number of photodector was reduced to a single device due to the possibility of switching the LEDs on and off quickly. 2.2 LEDs Energy sources used in pulse oximetry are monochromatic ideally with the option of using the expensive semiconductor lasers. Early pulse oximeter used similar wavelengths of 660 nm for red light and 940 nm for near infrared. Therefore, LEDs of 660nm and 940 nm were used in these designs. However, modern devices used additional wavelengths. Doped Material Wavelength Light Ga.28In.72As.6P.4 1250 nm Infrared Ga 1100 nm GaAsSi 940 nm GaAs 900 nm GaAIAs 880 nm GaAIAs 810 nm Near Infrared GaP:ZnO GaAs.6P.4 780 to 622 nm Red GaAs.35P.65 622 to 597 nm Orange GaAs.14P.86 597 to 577 nm Yellow GaP:N 755 to 492 nm Green GaAs-phosphor (ZnS, SiC) 492 to 455 nm Blue GaN 455 to 390 nm Violet GaN GaS2 455 to 350 nm Ultraviolet Standard pulse oximetry have the isobestic point (805 nm) at which there are two wavelength concentrated at each side. As stated earlier, two wavelengths of 940 nm (infrared) and 660nm. The absorption spectra are flat at 940nm allowing the calibration to be immune to the variations in the peak wavelength. In addition to that, the difference between the absorption of reduced hemoglobin and the absorption of oxygenated hemoglobin at 660nm is large ,causing a flat curve and allowing the detection of changes in absorption caused by small changes in oxygen saturation . 2.3 Probe The probe of a pulse oximeter consists of light emitting diodes as energy source having a perpendicular output through the extremity towards a semiconductor photo-detector. The mechanical design prevent mispositioning that cause errors in calibration 2.3.1 Differential Amplifiers in the probe Nowadays differential amplifier techniques are being used in the plethysmograph signal to enhance the common mode electrical and magnetic noise reduction. The amplification is done between the conductor signal and the current pathway. This amplification is performed to prevent the electromagnetic interference (EMI) from affecting the probe or the lead. Due to the fact that, a small voltage signal cause the voltage generated by the EMI to be greater than the signal itself. Two identical conductors from the detector to an amplifier are feed through the differential amplifier. The resulting output will be the absolute value of the signal from conductor 1 minus the signal from conductor 2. The advantage of using such a differential amplifier is that the induced voltage from the EMI will be two identical signals that will cancel each others. The energy output of the photo detector must be immune to the variation in the fingers thickness, leading to a variable energy output from the LEDs. This criterion requires detectable and unsaturated energy levels that reach the semiconductor. In the other hand, the current passing through the LED must be varied to allow the variation in the intensity of the output over several orders of magnitude. This variation is necessary to prevent high level of energy from passing through the tissues, causing heat damage. 2.3.2 LED in the probe LED used in pulse oximetry have a bandwidth between 10 and 50 nm and a 15 nm centre wavelengths variation. On the other hand, variations in the driving current cause errors at the red LED but doesnt have any effect on the near infrared LED. These facts are related to the absorption spectra; it is flat near infrared region and steep in near the red region as shown in figure 3. This will lead to an increasing inaccuracy in pulse oximeter as the oxygen saturation decreases. This problem can be solved by two different ways: 1. Selection of LED having an acceptable range of errors in the center wavelengths. 2. Measurement and calibration of center wavelengths into actual wavelength The calibration is usually performed by the use of a fixed resistor attached to the connector of the probe lead. This resistor will automatically set the probes wavelength to the one of the red LED. 2.4 Photo-detector In pulse oximetry, a single photo-detector made of silicon photodiode is positioned perpendicularly to the LED in order to detect the energy from both LEDs. Due to the fact that semiconductors are sensitive to external energy and light, general semiconductors have their size increased. However, Semiconductor photo-detectors having their sensitivity varying with wavelength, take advantage of the limited photosensitivity to limits the choice of device and the scope of wavelengths. The silicon photodiode is characterized by the direct correlation between the output and the incident light and its wide dynamic range. On the other hand, phototransistors have more electrical noise, but more sensitivity than photodiodes. The electrically screened flexible cable carries the LEDs power and the small signal from the photo-detector. The cables also have the function of temperature detection of the probe and the skin using conductors. Finally, in order to be immune to the mechanical artifacts caused by movement, the cable must be flexible and light. 2.5 Electronics 2.5.1 Electronics circuitry Pulse oximetry makes use of different electronics circuitry for different purposes: Amplifies the signal coming from the photo detector Separates the plethysmograph signals into red signals and infrared signals. Switching and controlling the current of the LED. Setting the gain of the signals to be equivalent to the other signal Divide the signal into arterial signal and other signals Convert the infrared signals and the red signals into digital signals using AD conversion. Computation of the ratio red to infrared. Eliminates artifacts Compute the value of oxygen saturation Display of the computed values Managing the alarms settings The absorption of energy from the LED to the photo-detector creates the signal in the red and the infrared channels. This absorption is the assembly of different absorptions from various sources such as arterial blood and its pulsation, venous blood and tissues. The initial amplification stage is implemented by analog electronics, whereas calculation of spo2 stage is implemented with a microprocessor, the photo-detector signal is treated by electronics or microprocessors. The output signal from the analog part is processed by an ADC to be suitable for the digital part or the microprocessor. 2.5.2 Amplification stage The amplification is processed in different stages: The low amplitude photo-detector signal is amplified. The LEDs are energized in an alternating sequence with a short delay in between to allow the measurement of external light. The amplified signal is decomposed into three signals: red, infrared, and dark signal. The electronic filters remove the 1 KHz high-frequency switching, making the signal continuous and having different wavelength. The dark signal is subtracted from the DC levels to prevent problems from the energy source. The DC components of the infrared signal is equalized to the DC components of the red signal by changing the amplitude of a photo-plethysmograph signal . The red to infrared ratio is calculated from the amplitudes of the AC components. 2.5.3 Conventional Spo2 calculation methods Earlier pulse oximetry used one of two methods to calculate the spo2 values. The first method is solving simultaneous BeerLambert law equations. However, this method have many limitations such as one unknown, absence of scattering and turbidity, and the need for the path length to be constant. Due to the many limitations, this method is considered inaccurate and therefore rejected. The second and common method uses the red to infrared ration with a look up table to find the spo2 values. The thickness and size of the finger varies from one person to another, thus the optical density will also vary from one patient to another. However, the saturation of the semiconductor does not depend on the characteristics of the patient but only on the intensity of light. In order to have the same saturation, the same amount of light is applied to the patient regardless of the size and age. This can cause serious heat damage for children. The prevention of this problem is another microprocessors role. The microprocessor implements a correction factor that controls the LED current and synchronizes the LEDs intensities. The resulting current should be the minimum amount of light energy allowing the calculation of pulse oximetry while not damaging the tissue 2.6 Elimination of artifacts The intact calculated saturation values include the real values with some invalid values created by artifacts. Therefore, statistical averaging methods are used in order to remove these artifacts 2.6.1 Mechanical movement artifacts The mechanical movement artifacts are processed with the Nellcor algorithm. The Nellcor algorithm consists of the following steps: Divide the output signal from the differential amplification stage into pulses. Check the pulses for motion artifacts If the pulses do not contain motion artifacts, compare the identified pulse to the normal pulse. If the pulse contains motion artifacts, higher standards for the quality of the light motion signal are applied. The resulting pulse should be compared to the normal pulse If the pulse is not identical to the normal pulse, that pulse is rejected If the pulse is identical to the normal pulse, check if characteristics of the indentified pulse are physiologically possible If the characteristics of the identified pulse are not physiologically possible , that pulse is rejected If the characteristics of the identified pulse are physiologically possible, the pulse is compared to the average of the preceding pulses If the pulse is not equal to the average of the preceding pulses, that pulse is rejected If the pulse is equal to the average of the preceding pulses, the pulse is divided at dicrotic notch . Then the whole pulse or the main component is selected for the calculation. Then, a filter based on confidence assessment is implemented Finally, the SpO2 value is calculated

Hollywood main stream cinema’s treatment of gender in the 1980’s Essay

To what extent is Rambo: First Blood Part 2 typical of Hollywood mainstream cinema’s treatment of gender in the 1980’s? Action films in the 1980’s reflected the changes and insecurity’s within American society. There had been a rise in feminism meaning that the masculine form and dominance was being undermined and white working class males did not know where their place was in society. It was also in the immediate time after the Vietnam War and confusion and anger still lingered. The Vietnam War divided the American nation as a whole because, as it has been in recent times with the war in Iraq, people didn’t fully understand why America needed to impose their presence in a country where they felt they had nothing to gain. The action film in the 1980’s introduced a hero that differentiated masculinity and femininity using the form of the body as a way of ensuring power, dominance and self-respect. Rambo: First Blood Part 2 is a typical film of this era in terms of masculinity and the ways in which men and women are portrayed. In the film Rambo: First Blood Part 2 Sylvester Stallone portrays a typical action hero of the ‘war film’ genre in the 1980’s but also an outcast of society after the Vietnam War. He is a veteran of Vietnam and came home to find that everything he had known had changed and he was no longer considered an honourable soldier but more as a war criminal. Rambo’s mission in this film is to go back to Vietnam and see if he can find a camp that he is told has many POW’s. If he finds the men, he can only take photographs but he has a problem with this and risks his own life to save them. He is very strong and muscular and is able to defeat the soldiers, Russian and Vietnamese, single handed. Douglas Kellner states that the film; ‘Follows the conventions of the Hollywood genre of the â€Å"war film†, which dramatizes conflicts between the United States and its â€Å"enemies† and provides a happy ending that portrays the victory of good over evil.’ (Kellner, 1994, p.10) This means that America always won no matter who the enemy was. In reality this is something that America could not accomplish. There was no happy ending and there were no immediate heroes. Rambo is allowed to bring glory upon America and diffuse a situation that could have cost the American military even more respect and dignity. America had lost some of its power within the world and they strived to get it back. It had lost its first war and it had become important to remasculinize America. There was a growing fear of communism in the country and displaying male heroes which went against the communist regime was their idea of establishing the ideal throughout the world by a means of globalization. Globalization had been taking place throughout the history of cinema by a means of film that was imported and exported to places around the world. In effect most of the action films set in Vietnam, and other films which hold a strong view of patriotism and heroism within America in the 1980’s, can be seen as propaganda films against the rise of communism. The purpose, with or without the knowledge of the audience, was to get the idea across to a mass audience that communism was against the principles of the country. In Rambo the ‘evil’ characters are the Vietnamese and Russian soldiers and ironically, it turns out that the greatest threat to Rambo is not the Vietnamese, although they do pose a strong force, it is the Russians. The Russians are shown as being extremely strong, relentless, and willing to put a man through torture to get what they want. Nevertheless, whatever the Russians do you cannot beat a man with as much physical and mental strength as Rambo. This follows a pattern throughout action films in the 1980’s. One film that is suggestive of this is Rocky 4. Rocky 4 (1985) also stars Sylvester Stallone but this time he is a boxer. He is fighting against a strong Russian fighter named Ivan Drago. Drago is very tough and stands at over 6ft tall. The Russian crowd all stand behind their fighter but when the final fight is over and Rocky defeats him with all of his strength the Russians begin to show support for Rocky and boo their fighter. This is the film industry’s way of evoking patriotism and the ever-growing fear of the communist regime after the Cold War. Philip L. Gianos states that; ‘The advent of Vietnam in film provided an opportunity for filmmakers who were denied an actual shooting war: a parallel, surrogate setting in which cold war themes could be played out.’ (Gianos. 1998, P.159) The first response from the film industry during this time was a set of anti-communist films to respond to the changing political environment. The villains are almost always portrayed as foreign internationals such as Russian, German, and sometimes English and they are usually a communist operative. They are never American in these films because the hero is American. He is fighting for his country and if it were another American he is fighting against he is effectively fighting against America. Other action films that were released at that time include, The Terminator, Rocky, Predator, and Die Hard. Millions of people worldwide, mainly consisting of young males went to see these films at the cinema. They gave them a chance to ‘latch on to big, muscular, violent men as cinematic heroes.’ (Katz, 1994, p134) These heroes gave the audience the chance to gain self-respect and security as it represented a masculinity that was unaffected by the rise of feminism. Gender roles had been reversed due to the growing rise of a feminist movement that showed women were increasingly moving into the workplace rather than staying at home. The displaying of the male physique and the physical torture it goes through to enable glory and victory over evil is further suggestive of masculinity in crisis and the gain of global respect. Women could not gain this kind of respect because they could not attain that degree of physical strength and endurance so therefore this was one thing that they couldn’t take away from men. The female role in the action film of the 1980’s appears at first glance to be on equal footing with the male. However, there are some differences in the ways in which they go about their missions. In Rambo: First Blood Part 2 the main female character, Co Bao, is strong, resourceful and a very capable fighter. She is Rambo’s contact in Vietnam and later becomes his love interest. During the film she cautions Rambo to follow his orders and when she goes to save him from the Russian’s in the POW camp she uses a different technique than Rambo. While Rambo attacked her captor from behind and overpowered him she sneaked into the camp as a prostitute. Therefore the issue of strength and power is present in the male character but in the female character it is more about subtlety and intelligence. Rambo is the definitive male of 80’s cinema and was joined by characters such as John McLain (Die Hard) and Rocky Balboa (Rocky). In these films the main action centres around one hero and the female character is usually the love-interest or accomplice. In previous war/actions films and Vietnam films the veterans were seen as either psychopaths, such as Travis Bickle in Taxi Driver, or tragic characters, Bob Hyde in Coming Home. In the films of the 1980’s, however, the hero fights back. In Rambo Part 2 Rambo can be seen as an anti-hero because of his rebellious behaviour by going against his orders to leave the POW’s and by telling Murdock that he will come and get him when he gets back from the jungle. This makes his character more dangerous and exciting to the audience as you don’t know what he is going to do. He has many people after him in Vietnam but he also has enemies at home. He has to deal with ‘home-grown discrimination’ because of the war and in effect he is no longer fighting for his country. He is doing it for the comrades that he fought with; ‘In these films the enemy is not the enemy in a war that is officially over but rather the civilian and military leadership that failed to win the war’ (Gianos. 1998, p.166) After Co Bao is killed Rambo channels his emotions into retaliation and thus becomes a fighting machine that is only out for revenge. Before she was killed he was ready to leave after finding that Murdock sent him out just to get free of him and stem reports that there were POW’s still in Vietnam. The style of the film helps to build the perception that he is a ‘god’ and that he is invincible. The use of lighting and camera angles are used to enhance his physique and the fast paced editing in the action shots are used to show that he is fast, strong and practical in the ways he attacks his enemies. Rambo shows us the ideal, very well-built muscular body of the white male in a place where he appears to belong. Commonly used iconography for Vietnam films included dense jungle, camouflage equipment and hi-tech weaponry. He uses the jungle to an advantage and appears to know it better than those who live there. He uses his initiative and intelligence in the jungle and is able to use it to gain the upper hand in a battle. One example of this is the scene in which he attacks a US soldier after he hides in a bank of mud with his eyes being the only thing visible. The male body in these films ‘constructs the white man as physically superior, yet also an everyman, built to do the job of colonial world improvement’ (Dyer, 2002, p.269) The fact that the superior build of the hero’s body establishes him as an everyman means that it is something that any man can attain – as long as you are white. Black men are rarely portrayed in this manner and if they are they are usually the villains of the movie and end up being defeated. In conclusion, the gender representation in the film is an effort from the United States to fulfil the growing need of remasculinizing American society, in particularly, in the dominant white majority of the working class. With the rise of feminism, fear of communism, political scandals and the Vietnam War, it became imperative for America to try and rebuild the image of men in a positive light. Rather than focusing on men as a collective these films focused on one individual and therefore a view of machismo, strength and determination became the ‘norm’. The films of the 1980’s became a kind of vessel of the ideal and most of these films are still popular in today’s society and may still be what some men aspire to be. If you were like these men you were considered to be manly and if you weren’t you were understood to be weak and not the ‘typical’ American male. The male hero in these films was put there to win. America needed a hero and they found him in these films. The masculine form was in crisis and the wholesomeness and fearless heroes could make an impact on the male audience who would then seek to be like the characters they watched on screen. Bibliography Gianos P.L (1998) Politics and Politicians in American Film, London, Greenwood Press Dyer, R, (2002) The White Man’s Muscles in Adams. R and Savran. D (eds) (2002) The Masculinity Studies Reader Oxford, Blackwell Publishers Jeffords S. (1989) The Remasculinization of America: Gender and the Vietnam War Indianapolis and Bloomington, Indiana University Press Kellner D. and Katz. J (1994) in Dines G and Humez J.M (eds) (1994) Gender, Race and Class in Media London, Sage Publications

Original Writing- Jonas Brothers

Although many people don't realise it, music plays a big part in everyday life. If its auditioning for the X-Factor, going to gigs every week, singing hymns at mass, singing to your favourite tunes in the shower or just listening to the radio on the way to work, we all like our music. It gets us though the days and has a big influence on what we do. Music separates the people with the many different genres it offers and some very talented people are behind it all. Considering this I would like to tell you about one of my favourite bands; the Jonas Brothers. Jonas Brothers are a VMA-nominated American boy band. The band consists of three brothers; Kevin, Joe and Nick. They come all the way from Wyckoff, New Jersey and have released three albums; It's About Time (2006), Jonas Brothers (2007) and recently, A Little Bit Longer (2008), and one soundtrack; Camp Rock (2008). The band gained their popularity on the children's television network; Disney Channel, which is where the Disney Channel Original Movie Camp Rock , starring the Jonas Brothers, was first shown. The band star in the movie as a boy band named Connect Three. One of my reasons for liking the Jonas Brothers, is the fact that they are well-known for their wholesome, family image. The brothers are all committed Evangelic Christians, and wear purity rings on their left-hand ring finger as a sign to not have pre-marital sex, of which neither of these things they are ashamed of or afraid of showing. Joe stated that the rings symbolize â€Å"a promise to ourselves and to God that we'll stay pure 'till marriage† and Nick thinks that â€Å"its pretty awesome, and the rings are just one of our ways of kind of like being different to everybody else out there†. They also abstain form alcohol, tobacco and drugs. Another reason for liking the Jonas Brothers is the fact that in 2007 they earned about $12 million dollars and donated 10% of it to their charity, Change for the Children Foundation. The charity is a foundation started by the Jonas Brothers, where the contributors donate to charities such as, Nothing but Nets, American Diabetes Foundation, St Jude Children's Research Hospital, Children's Hospital Los Angeles and Summer Stars: Camp for the Performing Arts. Their reasons for stating the charity is to â€Å"support programs that motivate and inspire children to face adversity with confidence, determination and a will to succeed†¦ kids helping other kids who are a little less fortunate.† Paul Kevin Jonas II, also known as Kevin, is the oldest of the brothers aged 21 and born November 5th 1987. He plays lead guitar (usually a Gibson Les Paul) and backing vocals. Kevin is also a songwriter and helped to write the bands self-titled album Jonas Brothers. Joseph Adam Jonas, was born August 15 1989, making him 19. He sings lead vocals, plays percussion and has played the guitar in the song A Little Bit Longer. Joe originally had no intentions of becoming a singer; he wanted to be a comedian and work on the show All That Nicholas Jerry Jonas, is the youngest of the band at only 16 years of age, born September 16 1992. He plays rhythm guitar (usually a Gibson SG in the original re stain colour), lead vocals with brother Joe, piano in the songs When you Look me in the Eyes and A Little Bit Longer, and drums in the songs, Australia, Can't Have You, Sorry and Video Girl. He can play various other instruments also. On November 16 2005 (aged 13), he was diagnosed with type 1 diabetes. Franklin Nathaniel Jonas, is the baby of all the brothers, of only 8 years of age and was born September 28 2000, and isn't in the Jonas Brothers, but being the bands younger brother he still plays a big part in their lives. He is also known as the Bonus Jonas and Frank the Tank. He will debut with his brothers on J.O.N.A.S!(a Disney Channel Original Series (2009)), and may have a small appearance in Camp Rock 2. Other members of the band are: John Taylor who helps produce for the band, as well as plays guitar. Greg Garbowsky has been with the brothers since they started out. He plays bass guitar and keeps a blog of Life on the Road with the Boys. Jack â€Å"Flawless Lawless† Lawless joined the band in early 2007, and has replaced former drummer Alex Noyes. Ryan Liestman plays the keyboards for the group. The single, A Little Bit Longer, released earlier this year, was written by Nick Jonas himself and is about his fighting battle to carry on pursuing his dreams with his diabetes. He sings alone in this song, about how â€Å"you don't know what it feels like until its gone†. This song is very emotional and on occasions, Nick has been seen to be crying on stage to this particular song. He's said â€Å"Luckily, I've got some really great people around me that really help me manage my diabetes. And it hasn't slowed me down yet, and I'm not planning on letting it do that. So I'm going to continue to do what I love and if I have occasional low or high blood sugar, it will be all right because I've got some really great people surrounding me.† With the Jonas Brothers being so talented and successful at such a young age, I find them so inspiring to listen to and am proud to be a fan of theirs. You could be in any situation, but you're holding on because you don't want to give up on love. Say you're in a terrible situation†¦you can always find the light if you look hard enough.

The Study of Stone in Archaeology or Lithics

Definition: Archaeologists use the (slightly ungrammatical) term lithics to refer to artifacts made of stone. Since organic materials such as bone and textiles are rarely preserved, the most common type of artifact found on a prehistoric archaeological site is worked stone, whether as prepared tools such as a handaxe, adze or projectile point, hammerstone, or the tiny flakes of stone called debitage, which resulted from the construction of those tools. Lithic analysis is the study of those objects, and can entail things like determining where the stone was quarried (called sourcing), when the stone was worked (such as obsidian hydration), what kind of technology was used to make the stone tool (flint knapping and heat-treatment), and what evidence there is of the tools use usewear or residue studies). Sources We whole-heartedly recommend the Stone Age Research Collection pages of Roger Grace, for those who want to delve deeper.Andrefsky, Jr., William 2007 The application and misapplication of mass analysis in lithic debitage studies. Journal of Archaeological Science 34:392-402.Andrefsky Jr., William 1994 Raw-material availability and the organization of technology. American Antiquity 59(1):21-34.Borradaile, G. J., et al. 1993 Magnetic and optical methods for detecting the heat treatment of chert. Journal of Archaeological Science 20:57-66.Cowan, Frank L. 1999 Making sense of flake scatters: Lithic technological strategies and mobility. American Antiquity 64(4):593-607.Crabtree, Donald E. 1972. An Introduction to Flintworking. Occasional Papers of the Idaho State University Museum, No. 28. Pocatello, Idaho, Idaho State University Museum.Gero, Joan M. 1991 Genderlithics: Womens roles in stone tool production. In Engendering Archaeology: Women and Prehistory. Joan M. Gero and Margaret W. Co nkey, eds. Pp. 163-193. Oxford: Basil Blackwell.