1.  Field of the Invention
The invention relates to a fallopian tube occlusion device and method for use.  More particularly, the invention relates to a fallopian tube occlusion device that uses the unique shape of the uterine cavity to ensure delivery and proper positioning thereof, as well as a method for using the occlusion device. 
2.  Description of the Prior Art
Several types of intrauterine devices (IUDs) are available and used worldwide.  There are inert IUDs, copper IUDs and hormone impregnated IUDs.  There is ongoing controversy regarding the mechanisms of action of IUDs in humans.  Classically, the view was that the IUD in humans acted predominantly after fertilization to prevent implantation, but evidence has accumulated for some effects before fertilization.  As a general rule, the pre-fertilization effects are not enough to prevent fertilization and, therefore, the post-fertization effects are most important.  The post-fertilization mechanisms of action of the IUD include slowing or speeding the transport of the early embryo through the fallopian tube, damage to or destruction of the early embryo before it reaches the uterus, and prevention of implantation.  This mechanism of action is perceived as an early abortion by some, and prevents many patients from using IUDs as a temporary mode of contraception.  Another problem with IUDs is expulsion from the uterus and subsequent unwanted pregnancy.  Other potential complications of IUDs are uterine infection, uterine perforation and most important ectopic pregnancy.  Ectopic pregnancy is a condition where the embryo has implanted outside of the uterine cavity, usually in the fallopian tube.  This condition is also hazardous to the patient and can lead to internal bleeding and severe morbidity and even mortality.  This potential complication also deters patients from the use of IUDs. 
Another problem affecting many women is endometriosis.  One of the proposed mechanisms of endometriosis is flow of the menstrual blood through the fallopian tubes into the peritoneal cavity.  This condition usually affects younger patients and permanent tubal ligation or occlusion is not warranted.  It is thought that the temporary tubal occlusion might prevent the flow of blood through the fallopian tubes and into the peritoneal cavity and thus might improve the patient's symptoms. 
Fallopian tube ligation is usually performed surgically.  Transvaginal tubal occlusion has also been described before.  There are several methods of tubal ligation and occlusion. 
With the foregoing in mind, a need exists for an improved IUD replacing currently marketed IUDs and other methods of contraception, such as, tubal ligation.  The present invention allows for use of a device that enables tubal occlusion, either permanent or temporary, based on the unique shape of the uterine cavity.  This device has the potential for a reduced rate of tubal pregnancy and, therefore, be used by a larger patient population, including those that adamantly opposed to abortion.  The present invention also allows nonsurgical tubal occlusion that can be done as an office procedure and without the need for surgery or the need for visualization of the fallopian tube orifices either radiologically or with a hysteroscope.  The present invention also provides a treatment option for women that suffer from endometriosis, an often debilitating disease that commonly affects younger women.  The present occlusion device uses radial force and inherent properties in its construction to prevent migration or expulsion of the occlusion device.  As such, the present invention may be used with the following procedures: contraception, either permanent or temporary; treatment of endometriosis; and potentially treatment of other causes of abnormal uterine bleeding or pelvic pain.