Patent ID: 6575891
Filing Date: 2003-06-10
Classification: A61N

Abstract:
A system for delivering a flexible ribbon with radioactive source elements to a desired site for medical treatment of a patient, comprising:a main housing; a containment vessel removably affixed to the main housing and having a shielding bottle of radioactive shielding material; a hypotube within the containment vessel defining a narrow passage for a ribbon extending from a proximal end to a distal end of the containment vessel; a luer-lock fitting affixed to and communicating with a distal end of the hypotube, for removably attaching a catheter defining a ribbon lumen to the luer-lock fitting; a quick release mechanism removably affixing the containment vessel to the main housing; a drive mechanism within the main housing for extending and retracting a ribbon out through the hypotube and luer-lock fitting, including a rotatable reel having a spiral groove for receiving the ribbon; and a flexible ribbon with radioactive source elements at a distal end of the ribbon, mounted about the reel and received in the spiral groove and extending through the hypotube; such that in the unlikely event the drive mechanism renders the ribbon unretrievable, the quick release mechanism may be actuated to remove the containment vessel from the main housing and exposing the proximal portion of the ribbon, thus allowing the ribbon to be manually retracted until the radioactive source elements are within the containment vessel shielding bottle; wherein the ribbon exits the groove on the reel at a drive point, the drive point tending to remain at a constant angular position with respect to the main housing, and the drive point tending to shift in a lateral direction parallel to the rotational axis of the reel as the reel rotates and extends or retracts the ribbon, the system further comprising a mechanism for compensating for such shifting of the drive point; wherein the compensating mechanism further comprises a screw thread having a pitch equal to that of the groove defined by the reel, the reel being mounted about the screw thread such that the reel shifts laterally an equal and opposite distance as the drive point shifts during rotation of the reel.