section 1201 will remain within the patient 39 s body and be incorporated into the vena cava fig1 and 15 depict a fourth embodiment of the present invention similar to the third embodiment the filter 101 is composed of two pieces the base section 1401 and the filter section 1403 legs 1405 however contain weakened sections that are predisposed to be broken when desired the weakened sections can be designed to be broken by the application of a low voltage electrical current or be a physically weaker substance fig1 depicts the removal device to be used for the fourth embodiment in which hook 1503 engages disengaging hook 1407 and filter section 1403 breaks off at predetermined weakened sections 1409 once completely broken off the filter section 1403 can be retracted into the removal device and extracted from the patient fig1 and 17 depict yet another embodiment of the present invention filter 101 is composed of a single wire structure and shaped in the form of a cone to filter the blood stream at the narrow end of the filter the apex of each return bend is shaped in a loop of approximately 1 mm inside diameter stacking all of the loops on top of each other forms the conical end a hitch pin 1601 is inserted through all the loops and holds the loops and the filter legs in the filtering conical shape the hitch pin 1601 is retains its position in the loops by.