Introduction
Magnetic materials are categorised as either hard or soft. A soft magnet material is easy to magnetise/demagnetise, whereas hard magnetic materials retain their magnetic properties after being magnetised. Permanent magnets are made up of hard magnetic materials which is able to create its own persistent magnetic field once magnetised. They can be made in different sizes and strength and thus, making them implantable into the body without anatomical restriction.
Different kind of magnets are nowadays being used in medical application from magnets for retention to guides for catheters in brain surgery. Due to the increased development of permanent magnets more and more magnetic materials are being used in medical applications. These report will concentrate on the medical devices such as Cardiac Rhythm Management Devices (CRMD): pacemakers implantable, cardio defibrillators and bone distraction. These applications use activation magnets which is contained in a medical device which is then implanted into the human body. As medical device is exposed to an external magnetic field they either activate or deactivate the device. Since the magnetic material is used inside the body it has to be able to perform an appropriate response in the host in the given application. This is often achieved with encapsulation of the magnetic material in order to stop any interference of the magnet with the body which also ultimately eliminates risk of corrosion1.
Implantable Pacemaker
An implantable pacemaker is used to assist the normal contraction rhythm of the heart when the heart’s own generated electrical impulses become impaired which is caused by heart block – delay or no conduction between atria and ventricle.
These pacemakers c...
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During the late 1970's, the world of diagnostic imaging changed drastically due to the introduction of Magnetic Resonance Imaging, also known as MRI. For over 30 years, they have grown to become one of the most significant imaging modalities found in the hospitals and clinics ("EDUCATIONAL OBJECTIVES AND FACULTY INFORMATION"). During its ancient days, these machines were referred to as NMRI machines or, “Nuclear Magnetic Resonance Imaging.” The term “nuclear” comes from the fact that the machine has the capability of imaging an atom's nucleus. Eventually, the term was dropped and replaced with just MRI, because “nuclear” did not sit well with the public view ("EDUCATIONAL OBJECTIVES AND FACULTY INFORMATION"). Many people interpreted the machine to produce an excess amount of radiation in comparison to the traditional X-ray machine. What many of them were unaware of, MRI does not disperse a single ounce of ionizing radiation making it one of the safest diagnostic imaging machine available to this date. MRI machines actually use strong magnetic fields and radio waves to produce high quality images consisting of precise details that cannot be seen on CT (Computed Tomography) or X-ray. The MRI magnet is capable of fabricating large and stable magnetic fields making it the most important and biggest component of MRI. The magnet in an MRI machine is measured on a unit called Tesla. While regular magnets commonly use a unit called gauss (1 Tesla = 10,000 gauss). Compared to Earth's magnetic field (0.5 gauss), the magnet in MRI is about 0.5 to 3.0 tesla range meaning it is immensely strong. The powerful magnetic fields of the machine has the ability to pull on any iron-containing objects and may cause them to abruptly move with great for...
The pacemaker system is divided into 2 parts and it is placed underneath the skin below the clavicle. The first part is the pacemaker itself, which is like a computer with batteries. Second part is the electrodes that with the help of the mobile x-ray pictures will be placed correctly. The procedure only takes a little less than a hour. There are different sorts of pacemakers and to make sure it is used most effective there are pacemakers which is helping only where it is needed. The reason for that is so that the heart’s natural way of working is disturbed as little as possible. (Hjärt-Lungfonden, 2008(3) The picture below show the stimulation of the a heart muscle from an electrode that is attached to the part of the pacemaker which contain the batteries.
The MRI works by using hydrogen atoms’ magnetic properties within the human body to produce high quality images. These protons of the hydrogen atoms can be look upon as bar magnets, in normal situations, they will flow inside...
What I wanted to talk about today is this life save device called a automated external defibrillator. It has become the number one way to resuscitate a person who has had a cardiac arrest unwitnessed by emergency medical services and who is still in persistent ventricular fibrillation or ventricular tachycardia. Many people have played a big role in creating this device to become more efficient, smaller and easier to use for the general public. Here are just to name a few that played a part in the creation for this device: Claude Beck, James Rand, Paul Zoll, and Frank Pantridge. The first use of a defibrillator on a patient was in 1947 on a 14 year old boy. Claude Beck was performing a open-chest surgery when the boy went into fibrillation. Beck manually massaged his heart for 45 minutes until the arrival of the defibrillator. The defibrillator he used during surgery was made by James Rand and had silver paddles the size of large teaspoons. In 1956, Paul Zoll performed the first successful external defibrillation with a more powerful defibrillator. A major breakthrough in emergency medicine occur in 1965. At the time a majority of coronary deaths occurred outside of the hospital setting since defibrillator required a main power source and were only available in hospitals it made them pretty much useless in saving lives outside of a hospital setting. Frank Pantridge often referred to as the Father of Emergency Medicine, made the first portable defibrillator in 1965. This device was power by a car battery and weighted approximately 70 kg (155 lbs). By 1968 he was able to create a defibrillator that was safer to use and only weighted 3 kg (6-7 lbs). It was argued that their was a possibility of misuse of the device if given to a unt...
...gnetic. This new magnetic state stems from the fact that the spins are interacting by the double exchange interaction. Subsequently the insulating state changes to semiconductor. Furthermore, the general concept is that ferromagnetic materials favours metalicity.
Magnetic resonance imaging (MRI) is considered as one of the pioneers in medical imaging for diagnosis of pathologies involving soft tissues and internal structures. MRI provides good contrast resolution between different soft tissues of the body especially in brain, muscles, heart etc compared to other medical imaging modalities like computed tomograpgy (CT) and conventional radiography which utilizes x-rays for imaging. The other important aspect of MRI versus other imaging modalities like CT and conventional radiography is that MRI uses no ionizing radiation like x-rays for imaging, instead it uses a strong magnetic field to align the magnetization of some atoms within the body , then uses radiofrequency pulses to systematically alter the alignment of this magnetization. This process causes the nuclei of certain atoms to produce a magnetic field which can be detected by the scanner, and all this information is used to reconstruct an MR image of the scanned area of the body. The initial experiments by Sir Otto Stern in the year 1922 stated that physically the magnetic resonance ima...
Magnets are everywhere! They are in telephones, computers, stereos, vacuum cleaners, refrigerators, washing machines, cars, compasses, TVs, VCRs, your doorbell and many other places. The earth itself is also a magnet. The Greeks discovered a mineral over 2,000 years ago that attracted things that were made of iron. This mineral was found in a part of Turkey that was called Magnesia, so they called it magnetite. A magnet is any material that attracts iron or things made of iron. All magnets have two poles, exert force on each other, and are surrounded by a magnetic field.
Projectile or missile effects will be resulted from translational attraction. Translational attraction happens when one point of the ferromagnetic object is attracted to greater level than the object’s furthest point from attracting source (Figure 2-6). The difference in the spatial gradient attraction causes a more forceful attraction, which unintentionally increases the speed of object moving towards the magnet bore (Capizzani, 2009) and it will cause tearing of tissue if the implant is a fresh (Chung, 2002). The heavier the
The leading cause of death globally are Cardiovascular diseases. They are responsible for more than 17.3 million deaths per year, a figure which is projected to rise to 23.6 million by 2030. In the USA alone, around 2200 Americans die each day from these diseases which is one every 40 seconds. Cardiovascular diseases like strokes or heart attacks can be mitigated for an extent using implantable devices like heart pacemakers. As advantageous as it may sound, there are a few limitations to them too. For example, once the battery life has depleted, the device must be surgically replaced for uninterrupted regulation of the cardiac system. The average battery life of a pacemaker is about 7 years. This leads to repeated surgeries
Magnetism is very useful in our daily life. A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. In addition, magnetic field is a region which a magnetic material experiences a force as the result of the presence of a magnet or a current carrying conductor. Current carrying conductors also known as wire. As we know there have north pole and south pole of a magnet. If same pole of magnet approaches each other, there will repel each other. In contrast, if different pole of magnet approaches each other, they will attract. These are same with the electric charge, if same charge it will repel, different charge it will attract. Although magnets and magnetism were known much earlier, the study of magnetic fields began in 1269 when French scholar Petrus Peregrinus de Maricourt mapped out the magnetic field on the surface of a spherical magnet using iron needles [search from Wikipedia]. Noting that the resulting field lines crossed at two points he named those points 'poles' in analogy to Earth's poles. Each magnet has its own magnetic field which experiences a force as the result of the presence of a magnet and magnetic field has made up of magnetic field lines. The properties of magnetic field lines is it begin at the north pole and end at the south pole. The north pole always flow out while south pole always flow in. The closer the magnetic field lines, the strength of magnetic field increases. Furthermore, these line cannot cross each other. Ferromagnetism is the basic mechanism by which certain materials (such as iron) form permanent magnets, or are attracted to magnets. Ferromagnetic materials...
At the point when permanent magnet is utilized to create magnetic field in a DC motor, the motor is known as permanent magnet DC motor or PMDC motor. The motor can be easily to build. These motors are usually
Implantation of devices into the human body dates back to the ancient Egyptian practice of inserting seashells into the jaw to replace missing teeth. Despite this, it was not until the twentieth century that implanted devices, such as pacemakers, artificial hip
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The various types of magnets are used in countless facets in everyday life. Thousands of industries, including automotive, electronics, aerospace, craft, manufacturing, printing, therapeutic and mining utilise magnets so that their machineries, tools and equipment can properly function.