The Physics of Ultrasounds Essay - 1717 Words

The Physics of Ultrasounds Without the use of physics in the medical field today, diagnosis of problems would be challenging, to say the least. The world of medical imaging in particular has benefited greatly from the use of physics. Ultrasound is sound waves that have a frequency too high for humans to hear. With a shorter wavelength than audible sound, these waves can be directed into a narrow beam that is used in imaging soft tissues (Farr and Allisy-Roberts 183). As with audible sound waves, ultrasound waves must have a medium in which to travel and are subject to interference. In addition, much like light rays, they can be reflected, refracted, and focused (Farr and Allisy-Roberts 186). In general, ultrasound waves†¦show more content†¦With direct current, if pressure is applied to the disk, voltage is produced; if the pressure reverses, there is also a reversal of voltage. Alternating current can also be used, in which case the disk alternately expands and contracts. Based on the principle of piezoelectricity, alternating pressure on the disk likewise produces an alternating voltage (Farr and Allisy-Roberts 183-84). Transducers are used in either pulsed or continuous-wave modes, corresponding to the use of direct current or alternating current, respectively (Farr and Allisy-Roberts 183-84). Pulsed modes are basically used for imaging, while continuous wave modes are primarily used for therapy (Bushong and Archer 78). In a continuous-wave mode, the disk on the transducer expands and contracts back and forth, creating a continuous wave with the same frequency (f) as the vibrating transducer. Because the velocity ( ) of sound changes as it encounters objects of differing densities, the wavelength ( ) of the ultrasound changes proportionally, as given by the equation = =Æ’Ã ¡f, since the frequency is held the same. Thus, if a transducer is operating at 3.5 MHz, the wavelength of the ultrasound wave through average soft tissue (in which sound has a velocity ofShow MoreRelatedThe Physics of Ultrasound Essay888 Words   |  4 PagesWithout the use of physics in the medical field today, diagnosis o f problems would be challenging, to say the least. The world of medical imaging in particular has benefited greatly from the use of physics. Ultrasound is sound waves that have a frequency above human audible. (Ultrasound Physics and Instrument 111). With a shorter wavelength than audible sound, these waves can be directed into a narrow beam that is used in imaging soft tissues. As with audible sound waves, ultrasound waves must haveRead MorePrinciples of Physics in Ultrasound Essay1717 Words   |  7 PagesPrinciples of Physics in Ultrasound Physics has become an important part of medicine allowing specialist doctors and radiographers to rapidly access a patient’s condition and to help in long-term diagnosis. This enables doctor’s to treat patients before their condition deteriorates. This procedure would not be possible without the use of X-rays, CAT scans, MRI scans, ultrasound and endoscopes, which allow doctors to see inside the body with little or no surgeryRead More81253894 Ultrasound Physics Essay1171 Words   |  5 Pagesï » ¿ ULTRASOUND PHYSICS Name Institution a) Calculate the Acoustic impedance of subcutaneous tissue, muscle and bone. Assume subcutaneous tissue has a density of 1060kg/m3 (Hedrick 2003), muscle has a density of 1104kg/m3 (Madjor 2008) and bone has a density of 5065kg/m3 (Hedrick 2003). Give your answer in Mrayls. Please use speed of sound as 1540m/s for tissue, muscle and bone In ultrasound, Acoustic impedance (Z) is the quantity of measurement of resistance to sound when passing throughRead MoreHigh Intensity Focused Ultrasound Medical Physics1873 Words   |  8 PagesHigh Intensity Focused Ultrasound Medical Physics DJARI, Bryan â€Æ' Introduction Medical science has been established since the earliest time of the 1800’s. Using physics, scientist from all over the world are able to physically upgrade and improve both the effectivity and efficiency. In the fields of medicine, sounds, is an important factor to study. From many ranges of sound, ultrasound are sound or other vibrations having an ultrasonic frequency. With the use of ultrasound, doctors are able toRead MorePhysics Assignment : Medical Imaging1672 Words   |  7 PagesKathleen Anne Maguire 1/12/2016 Physics Assignment Medical Imaging MDPMS 1. Sound is travelling from material 1 to material 2. The density of material 1 id 25 kg ms-3 and the density of material 2 is 18 kg m-3. The speed of sound in material 1 is 1900 ms-1 and in material 2 is 18 kg m-3. The speed of sound in material 1 is 1900 ms-1 and in material 2 it is 700 ms-1. The acoustic impedance of each material Z= pV Acoustic impedance (Z) Density is (p) Acoustic Velocity (V) ForRead MoreUltrasound Technician, No Two Days1197 Words   |  5 PagesHowever for an ultrasound technician, no two days are exactly the same. Each shift brings with it a new docket of patients with different ailments. The ultrasound technician job description may call for a tech to be on their feet for a majority of the day; working in darkened rooms while performing their scan. Every appointment is different from the last and these sessions can last anywhere from 20 minutes to an hour. When finished, the reports are then sent to a radiologist for review and diagnosisRead MoreComparison of X-Ray and Ultrasound1217 Words   |  5 PagesX rays and Ultrasound are two of the main imaging techniques used in radiography. For the purposes of this essay, we will look at conventional x-rays and diagnostic ultrasound. Conventional x rays are non-invasive diagnostic techniques that are used to capture images of the bodys organs and bones. Diagnostic ultrasounds are high frequency sound wav es to create an image of soft issues in the body such as muscles, joints, and internal organs. As examined below, while both are used in diagnostic radiographyRead MoreEvaluation Of A Diagnostic Medical Sonographer1290 Words   |  6 Pagesmachinery to generate images and perform exams. They use ultrasound technology to obtain pictures of tissues and body organs. The career of sonography offers a wide range of specialties from obstetric and gynecologic to neurosonography. Some of the duties of a sonographer include prepare the patients for the procedure and examine the data recorded to give a detailed summary to the physician. Like any other healthcare professional, ultrasound technicians have responsibilities that are listed in theRead MoreWhat is a radiologist? The medical field is full of many different career paths. Some choose1000 Words   |  4 PagesRadiologists are medical specialists who use radioactive instruments and x-rays to diagnose and make treatment decisions regarding health problems. They examine various types of images including x-rays, computer tomography (CT scans), mammograms ultrasounds, and magnetic resonance imaging scans (MRI). Radiologists are skilled in operating machinery, monitoring imaging sessions, recommending courses of treatment, administering nuclear medications, examining patients, recording medical treatments, andRead MoreThe Process Of Becoming An Ultrasound Technician987 Words   |  4 PagesThe process of becoming an ultrasound technician can be one that is intimidating. However, it doesn’t have to be. With the help of an organization called American Registry for Diagnostic Medical Sonography (ARDMS), those seeking to be a sonographer can achieve their goals. Although there are many steps to take, it can be done. This paper will help instruct individuals who wish to go through the sonography principles and instrumentation (SPI) examination (Sonography Principles Instrumentation [SPI]

A Horror Movie free essay sample

Many things come to mind when people allow themselves to think about horror movies. Most may experience the feeling of butterflies in their stomach for fear or just pure excitement, but where does that fear or excitement come from? One might say that it is the anti-social instincts of horror that we all have hidden and festering deep down inside. A great horror author Stephen King once said,† that watching a horror movie helps us control the anti-social instincts we all have inside†. Some people might say that we are all a little crazy and anti-social in our own way and that some of us just hide it better. Many will argue that the impression and memories of that first horror film will always influence the way the one deals with horror but does not always make one’s anti-social inner monster want to surface. In most horror movies, some of us may agree and some of us may disagree that in some way that a horror movie has left a permanent indent in a single individual’s life. We will write a custom essay sample on A Horror Movie or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page For instance, let us look at the 1984 version of Wes Craven’s â€Å"A Nightmare on Elm Street†; this is the very first nightmare that occurred on a now well-known street. Although this movie is one of the greatest horror movies ever produced, a classic that will always haunt children and adults for many years to come. This movie keeps the person watching twitching with fear and on the edge of their seat. Most people that have watched this movie would say that this film is one that will make a person, sleep with the lights on, keep the closet door closed, and the windows locked. Although this movie is a great example of a film that will make you want to keep the lights on when you go to bed, it is also a great example of a film that will make the watcher always remember the plot of the story. â€Å"A Nightmare on Elm Street†, known by many as a great classical horror movie that describes its star actor Robert Englund, also known as Freddy Krueger as a child murder with the spirit of â€Å"the bastard son of 1000 maniacs†. In this film, Freddy Krueger is like any other parent that lives in the quite little neighborhood on Elm Street until the other parents figure out that Krueger is the one who has been abducting local children and killing them with different forms of torture. The other parents take matters into their own hands and burn Krueger alive, in a vow to the dark side Krueger gives up his soul and becomes a figment of our dreams that has a demon living inside of him. He claims his revenge on the descendents of those who murdered him in their sleep while they are dreaming, when they are most vulnerable. What makes this movie so scary and unforgettable for most people is not because of the bloody scenes or the fact that there is demon, with knives for fingers, and a scared face that kills teens in their sleep; it is because Wes Craven made this movie to seem as real as possible. The parts about this movie that make it seem so real is that Krueger would kill his victims by making their worst fears come to life in their dreams. For instance, his victims lie sleeping, their minds slip into what seems to be a seemingly illogical happening (terrifying hallucinations) that we experience in our dreams that make perfect sense at the time. In today’s modern science that is also known as Sleep Paralysis. Sleep Paralysis is a frightening form of paralysis that occurs when a person suddenly finds himself or herself unable to move for a few minutes, most often upon falling asleep. Sleep Paralysis can be referred to as errors of the neural transmission in the brain during REM sleep. So in other words his victims would feel as if what was happing at that time was real but in fact they were sleeping and there was no way to wake them up until it was too late. Although this film does make a good example of a movie that will keep someone on the edge of their seat, sleep with the lights on, and never forget the horrible child murder that we all know as Freddy Krueger. It is also a good example of a movie that after watching can give you the option to say whether your anti-social appetite has been satisfied. This movie’s plot is about a man who had an anti-social craving for murdering children, and because he gave into his appetite, he was transformed into what people would consider a demon. Therefore, that would lead people to believe that the statement that Mr. King sticks by â€Å"that watching a horror movie helps us control the anti-social instincts we all have inside† is in fact very true. It is said that great authors such as Stephen King does a person’s dirty work by creating horror films and books to help stop the craving of the instincts that the human race does so hard to try and hide. On the other hand, horror movies do not always satisfy that craving that all of us have deep down inside.