enclose a space between the first and second arms and thus helps to prevent the needle tip from projecting sideways out of the needle guard. In other words, the tension element adds to the protective effect of the needle guard.
In a further embodiment of the needle guard, a recess is provided in the proximal region of the first arm and/or the second arm of the needle guard. This recess increases the deflectability of the first arm and/or second arm in the region it is provided and thereby reduces the restoring force acting on the distal wall while this is being supported by the needle shaft. This allows the needle shaft to be moved more easily relative to the distal wall, as the frictional force acting on the needle shaft is reduced.
In a further embodiment of the needle guard, a groove is provided in a side of the distal wall, with the groove extending substantially in the axial direction. The groove acts as a guide groove for the needle shaft and aids the axial movement of the needle shaft relative to the needle guard. Moreover, the needle shaft is prevented from sliding sideways off the distal wall. Such a sideways movement would significantly increase the force required to move the needle shaft relative to the needle guard, which would prevent a correct functioning of the needle guard.
Further subject matter of the present invention satisfying the above mentioned object includes a needle guard according to claim 4 and a needle guard according to claim 7. In particular, such needle guards do not include stopping elements. Thus, the needle guard of the present invention can also be adapted such that it includes a recess and/or a groove as discussed above, but without including the stopping element. In this case, the outer profile of the enlargement of the needle shaft must be greater than the profile of the through-bore in the base portion of the needle guard, in order to prevent the needle guard from sliding off the needle in a distal direction.

WE CLAIM:
1. A needle guard (26) for use in a medical device, in particular for use
in a catheter device (10), including:
a base portion (44) made of a first material and having a needle passage (56) extending in an axial direction (A) from a proximal side (58) of said base portion (44) through said base portion (44) to a distal side (60) of said base portion (44) for movably receiving a needle shaft (28) having a principle outer profile;
first and second arms (46, 48) extending substantially in said axial direction (A) from said distal side (60) of said base portion (44), wherein said first arm (46) has a distal region (62) and a proximal region (64);
a distal wall (50) transversely arranged at said distal region (62) of said first arm (46); and
a stopping element (38) made of a second material different from said first material, which is arranged in said needle guard (26) distal from the base portion (44) and has a through-bore (74) with a profile that is adapted to the principal outer profile of the needle shaft (28).
2. A needle guard (26) in accordance with claim 1, wherein a recess (68) is provided in said proximal region (64) of said first arm (46) and/or said second arm (48).
3. A needle guard (26) in accordance with one of the preceding claims, wherein a groove (70) is provided in a side (66) of said distal wall (50) said groove (70) extending substantially in said axial direction (A).
4. A needle guard (26) in accordance with one of the preceding claims, wherein said stopping element (38) is arranged such that its