A radiopaque nitinol medical device such as a stent for use with or implantation in a body lumen is disclosed. The design of the piston improves the strength of the lower part and its resistance to material defects, and reduces production cost. The leads have a groove in the shape of a hemisphere or a down-set. An outlet of the inner tube is parallel to an airflow passage of the dust-discharging opening, such that when an exhaust gas is discharged from the inner tube, a siphon effect is produced at the airflow passage of the dust-collecting tube to suck and collect the dusts produced by the grinding wheel. The instrument is most useful when configured with incremental adjustment indicators, preferably in uniform increments, such that the working length can be determined by viewing the indicators. The delta-9-tetrahydrocannabinol may be administered orally, in capsules, or in tablets, or by injection, suppository, intranasal, transdermal, inhalant or sublingual administration.