US D559980 S1
The ornamental design for a medical instrument, as shown and described in the drawings.
FIG. 1 is a front perspective view of a medical instrument in accordance with the new design;
FIG. 2 is an enlarged side perspective view of a portion thereof;
FIG. 3 is a front view;
FIG. 4 is a rear view thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a bottom view thereof;
FIG. 7 is a right side view thereof; and,
FIG. 8 is a left side view thereof.