Pacemaker
A pacemaker is a small device placed under the skin of your chest or abdomen to help control irregular heartbeats. This device consists of a batter, computerized generator, and wires that generate electrical pulses to prompt the heart to beat at a normal rate.

Pacemaker User
It is used in patients who suffer from abnormal heart rhythms that beats too slow; fast or at irregular pace. This helps free them from fainting or feeling fatigue, aiding these patients to resume a more active lifestyle. It is recommended by doctors if ageing, heart disease or other factors that result in this abnormal heart rhythm.

What do pacemaker uses need to take note of?
· The patients are suggested to avoid vigorous exercise or heavy lifting for a short period after surgery. The physical activity allowed to exhibit must be discussed with personal doctor to ensure safety.
· The batteries of these pacemakers are needed to be changed every 5- 15 years. Patients that uses pacemakers are needed to avoid prolong or close contact to electrical devices or any other electrical devices that possess strong magnetic field.
· Certain medical procedures must also be followed to prevent any implications.

What are the risks involved in pacemaker transplant?
The risk of having any side effects is rare with a probability of less than 5%. Most patients are able to resume normal activities within a few days. However, some problems that can arise include:
· Swelling, bleeding, bruise or infection at areas that the pacemaker was placed.
· Patient may suffer blood vessel, nerve damage or a collapsed lung
· Negative side effect to the anaesthetic medication used for surgery

Corneal transplants
They are rarely rejected because corneas have no blood supply -- immune cells and antibodies do not reach the cornea to cause rejection. In addition, transplants from one identical twin to another are almost never rejected.

Knee replacements
The chance of getting an infection following artificial knee replacement is less than one percent. All patients receive antiobiotics for at least 24 hours after surgery to minimize the risk of infection.

David A. (2009) Transplant rejection. Retrieved February 4, 2010, from URAC Website: http://www.nlm.nih.gov/medlineplus/ency/article/000815.htm
Guy Slowik. (2009) Knee Replacement. Retrieved February 4, 2010, from FRCS Website: http://www.ehealthmd.com/library/totalkneereplacement/TKR_risks.html
NA. (2010) Pacemaker Implantation. Retrieved February 4, 2010, from the St. Jude. Medical, Inc Website: http://www.sjm.com/procedures/procedure.aspx?name=Pacemaker+Implantation
NA. (2010). Pacemaker Implantation. Retrieved February 4, 2010, from the American College of Cardiology Web Site: http://www.cardiosmart.org/HeartDisease/CTT.aspx?id=898#What Are the Risks of Pacemaker Surgery?