Hand Motion Analysis of Different Segments of a Procedure: Is One Segment Enough?

Purpose: This study aims to examine if the hand motions of operators associated with certain parts of central venous access are more important than others in distinguishing between experts and non-experts.

Materials and methods: Experts (n = 10) and Trainees (PGY2; n = 18) performed central venous access on a phantom 4 times each as their needle hand and ultrasound probe motions were tracked. Path length-time graphs were used to divide the procedure into three phases: (1) the access phase: visualizing the internal jugular vein on ultrasound and needle placement; (2) the wire phase: passing a wire through the needle; and (3) the confirmation phase: confirming the intravascular wire position and threading a dilator on the wire. Comparisons between trainees and experts were made for the complete trial, and each phase using Mann-Whitney U tests with Benjamini-Hochberg correction. Receiver Operating Characteristic analysis was performed to compare the performance of each phase in differentiating between experts and trainees.

Results: Motion data from 10 experts and 18 trainees was analyzed. Experts and trainees differed significantly for all the motion metrics (p < 0.001). A comparison of the phases showed that the access phase (AUC = 0.96; R2 = 0.79) and the wire phase (AUC = 0.95; R2 = 0.59) were able to distinguish between experts and trainees with an accuracy comparable to the complete trial (AUC = 0.94; R2 = 0.69).

Conclusions: The access phase of simulated central venous access can best differentiate between experts and trainees. This sample of hand motion performance may be able to simplify motion analysis of technical performance and obviate the need for recording hand motion for the entire procedure.