Procedure time and hand motion
| With NTT mean±SD | Without NTT mean±SD | Cross-over difference mean (95% CI) | P value | N | |
| Procedure time (s) | 183.0±56.1 | 206.8±56.2 | −23.8 (−57.4 to 9.8) | 0.16 | 26 |
| Needle hand—movements (n) | 55.7±23.6 | 58.7±20.8 | −3.0 (−13.2 to 7.2) | 0.55 | 26 |
| Needle hand—path length (m) | 4.07±1.57 | 4.15±1.08 | −0.08 (−0.78 to 0.63) | 0.82 | 26 |
| Probe hand—movements (n) | 1.1±2.4 | 3.2±6.7 | −2.1 (−5.2 to 0.9) | 0.16 | 23 |
| Probe hand—path length (m) | 0.39±0.22 | 0.79±1.05 | −0.40 (−0.88 to 0.08) | 0.10 | 23 |
NTT, needle tip tracking.