Intraoperative tremor in surgeons and trainees.

Objectives: Tremor may be expected to interfere with the performance of fine motor tasks such as surgery. While tremor is readily quantified in inactive subjects, it is more challenging to measure tremor as the subjects perform complex tasks. The objective of this work was to quantify tremor during the performance of a realistic simulated surgery.

Methods: Our novel surgical simulator incorporates a force sensor that allows identification and quantification of the intraoperative effects of tremor on the manipulandum. We have collected preliminary data from trainees and experienced surgeons carrying out multiple simulated anastomoses on silicone vessels, mimicking a procedure such as distal coronary anastomosis. We calculated transient and overall tremor intensity, and tested for a hypothesized 'learning effect'.

Results: Several of the recordings of intraoperative force data manifested distinctive features corresponding to substantial oscillation in the range of 8-12 Hz. We attribute this to enhanced physiological tremor. These early results indicate a significant reduction in the transmission of surgeon's tremor to the operative field from the first attempt to later attempts (P = 0.039, standardized effect size = 0.91), which may be associated with increasing confidence.

Conclusions: This new method does not just quantify tremor, but quantifies the transmission of tremor to a manipulandum in the operative field during high-fidelity simulated coronary surgery. This may be used to assess and provide feedback on the performance of trainees and experienced surgeons, along with other fields in which fine motor skills are of vital importance.