IntroductionMagnetic materials are classified as hard or soft. A soft magnetic material is easy to magnetize/demagnetize, while hard magnetic materials retain their magnetic properties after being magnetized. Permanent magnets are made of hard magnetic materials that are capable of creating their own persistent magnetic field once magnetized. They can be made in different sizes and strengths and therefore, making them implantable in the body without anatomical restrictions. Different types of magnets are used in medical applications today, from retention magnets to catheter guides in brain surgery. Due to the increasing development of permanent magnets, more and more magnetic materials are being used in medical applications. These reports will focus on medical devices such as cardiac rhythm management devices (CRMDs): implantable pacemakers, cardiodefibrillators and bone distractors. These applications use activation magnets contained in a medical device which is then implanted into the human body. When the medical device is exposed to an external magnetic field, they activate or deactivate the device. Since the magnetic material is used inside the body, it must be able to provide an adequate response in the host in the given application. This is often achieved by encapsulating the magnetic material to stop any interference of the magnet with the body, ultimately eliminating the risk of corrosion as well.1. Implantable Pacemaker An implantable pacemaker is used to assist the heart's normal rhythm of contraction when the heart itself is generated electrical impulses are impaired due to heart block – delayed or absent conduction between the atria and ventricles. These pacemakers c...... middle of paper ......-Defibrillator-ICD_UCM_448478_Article.jsp [Accessed: 20 April 2014 ]5) RedRock (2013) MEMS-based magnetic switching technology. [Online] Coto Technology [Accessed April 18, 2014]6) Reed Switch Development Corp (2013) What is a reed switch? [Online] Available from: http://www.reedswitchdevelopments.com/what-is-a-reed-switch.html [Accessed: 20 April 2014]7) David Prutchi. (2012) Cold Reed Switch Manufacturing [ONLINE]. Available at: http://www.implantable-device.com/2012/03/16/cool-reed-switch-manufacturing-video/ [Accessed 18 April 2014]8) Total Magnetic Solutions (2000) Alcino Magnets. [Online] Available from: http://www.magnetsales.com/alnico/Al1.htm [Accessed 22 April 2014]9) Advanced Magnetic Materials (2013) Types of Magnetic Materials. [Online] Available from: http://www.rare-earth-magnets.com/t-types-of-magnets.aspx [Accessed April 22 2014]