Joint replacement is one of the most common and successful operations in modern orthopaedicsurgery. It consists of replacing painful, arthritic, worn or diseased parts of the joint with artificial surfaces shaped in such a way as to allow joint movement.
Arthroplasty is a common but loose term for joint replacement. Other types of surgery are also arthroplasties. Other common and valid synonyms are total joint replacement, total joint arthroplasty, joint resurfacing and artificial joint surgery.
The impedance of extremeeties such as fingers, arms and legs changes with the blood flow in and out, so this provides another method for plethysmography.
The arterial pulse wave has a very low amplitude and is superimposed on the venous blood volume changes. Pulse wave measurements are possible in many locations including the head (this measurement is called rheoencephalography). Pulse waves can also be measured in the fingers and toes with photoplethysmography.
High blood pressure is a very common condition in modern society. It has been estimated that one in five Americans, around 50 million people, suffer from high blood pressure. In general more men than women have high blood pressure, and the number of sufferers of both genders increases rapidly with age.
In around 5% of cases of high blood pressure is caused by kidney problems, but the causes of the other 95% of cases are unknown. There are a number of factors such as race, age, obesity, stress, smoking and lack of exercise that can contribute to the likelihood of a person developing high blood pressure but usually no one cause is directly responsible.
