| 摘要 |
A brachytherapy device 10 for exposing to radioactivity a patient includes an elongate member such as a needle or cannula 12 adapted for introduction into the patient and also includes a stylet 14 slideably receivable in a longitudinal throughbore 16 in the needle 12. The device 10 also includes a portion 64 near either the proximal end 18 of the needle 12 or the distal end 24 of the stylet 14 which provides a local, defined amount of friction between the needle 12 and the stylet 14. The device 10 further includes an anti-static handle 34 connected to the needle 12. The handle 34 has an interior ramp surface 40 in communication with the throughbore 16 of the needle 12, frustoconical in shape and possessing an included apical angle of at least about 16°. The localized friction portion 64 can be a crimp or flange 48 on the stylet 14, or a crimp 44 or deformation 46 in or of the needle 12. The handle 34 is preferably composed of a polycarbonate, acrylic or acetal resin (such resins preferably being carbon-filled, or otherwise electro static dissipative), or a hydroscopic nylon blend. The device 10 is particularly advantageous in that the preferred ramp surface 40 in the handle 34 facilitates the insertion of seeds 26 of radioactive material and inert spacers 28 into the needle 12. The anti-static handle 34 eliminates, for practical purposes, the previously encountered risks of static interference, static cling of the spacers 28 and ignition spark generation. Finally, the localized friction portion 64 provides a controlled and predetermined amount of friction between the needle 12 and the stylet 14, preventing the stylet 14 from falling from the needle 12, while also preventing or reducing the risk of unintended ejection of the radioactive seeds 26 and spacers 28. Such friction is advantageously provided virtually the entire time any portion of the stylet 14 is received in the needle <BOLD |
