Needle deflection in tissue

摘要: Introduction: One of the factors that contribute to total needle-targeting error in medical procedures is needle deflection, which can lead e.g. hemorrhage, prolonged intervention time and decreased treatment efficiency. This deflection be defined as deviation from its suspected straight insertion path. In this study, we focused on effect tissue heterogeneity deflection. We hypothesized would bigger for insertions into heterogeneous than homogeneous specimens, due an unequal force distribution needle. Method: inner a 18Gauge trocar with triangular tip was inserted (5mm/s) multiple times at several positions 4 gelatin-, animal liver-, 2 human liver specimens. Deflection X- Y-direction measured using sliding gauges axial forces acting were captured sensor mounted onto hub. Axial analysis used give rough estimation mechanical properties Results: Results show increase magnitude variance specimens (Animal: Mean = 1.01mm, SD 0.54, Human: 0.83mm, 0.48) compared those gelatin (Mean 0.59mm, 0.26mm). Differences between median maximal almost zero 0.08, 0.04N), whereas differences 0.58, 0.23N), indicating nature tissue. Discussion: The results obtained study suggest causes deflect Both are A suggestion future research pathologic type known being more healthy