It is well known that the direction of a needle during a puncture deflects opposite to the alignment of the bevel at the needle tip (Fig. 1). The presented experimental study is intended to determine the extent to which the puncture route can be changed during CT-controlled puncture using a 22G Chiba needle with a length of 15 cm by adjusting the needle bevel and/or bending the needle (Fig. 2).

The effect of adjusting the bevel at the needle tip (Fig. 3),bending the needle hub 45° (Fig. 2)or the puncture speed on the puncture route was examined. Every test was performed with 5 needles.

The alignment of the bevel at the tip of the needle alone causes a change in the puncture direction of approximately ± 1° over a distance of 5 cm and about ± 2° over a distance of 10 cm. This represents a deviation from the target of ± 0.9 mm over a puncture distance of 5 cm and of ± 3.5 mm over a distance of 10 cm.

The effect ofbending the needle hub 45° Overall the most significant changes in the puncture direction can be achieved at a depth between 4 cm and 9 cm by bending the needle and aligning the bevel of the needle tip in the same direction (experiment 4). Here, the effects of bending and deflection due to the bevel of the needle tip combine so that the greatest changes in the puncture direction of about 8.6° are possible corresponding to a deviation from the target of 7.5...

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