Analysis of hand motion differentiates expert and novice surgeons.

BACKGROUND: The number of operations performed by a surgeon may be an indicator of surgical skill. The hand motions made by a surgeon also reflect skill and level of expertise. We hypothesized that the hand motions of expert and novice surgeons differ significantly, regardless of whether they are familiar with specific tasks during an operation. METHODS: This study compared 11 expert surgeons, each of whom had performed >100 laparoscopic procedures, and 27 young surgeons, each of whom had performed <15 laparoscopic procedures. Each examinee performed a specific skill assessment task, in which instrument motion was monitored using magnetic tracking system. We analyzed the paths of the centers of gravity of the tips of the needle holders and the relative paths of the tips using two mathematical methods of detrended fluctuation analysis and unstable periodic orbit analysis. RESULTS: Detrended fluctuation analysis showed that the exponent in the function describing the initial scaling exponent (α1) differed significantly for experts and novices, being close to 1.0 and 1.5, respectively (P < 0.01). This indicated that the expert group had a greater long-range coherence with an intrinsic sequence and smooth continuity among a series of motions. Likewise, unstable periodic orbit analysis showed that the second period of unstable orbit was significantly longer for experts in comparison with novices (P < 0.01). This demonstrates mathematically that the hands of experts are more stable when performing laparoscopic procedures. CONCLUSIONS: Objective evaluation of hand motion during a simulated laparoscopic procedure showed a significant difference between experts and novices.

Nonlinear analyses of heart rate variability in monochorionic and dichorionic twin fetuses.

AIMS: To examine whether the heart rate dynamics of a monochorionic diamniotic (MD) twin fetus is different from a dichorionic diamniotic (DD) twin fetus by nonlinear methods of time series analysis. METHODS: 32 fetal heart rate (FHR) recordings from healthy MD twin fetuses and 58 recordings from healthy DD twin fetuses were used. Nonlinear analyses included attractor reconstruction, calculation of the largest Lyapunov exponents, and estimation of correlation dimension. RESULTS: FHR of healthy twin fetuses was shown to have unique nonlinear characteristics. The largest Lyapunov exponent significantly increased during the pregnancy period. In 30-36 weeks, correlation dimension in MD twins was significantly lower than that in DD twins. In DD twins, we observed a significant increase of correlation dimension from 22-29 to 30-36 weeks. In 22-29 weeks, the difference of the values of correlation dimension in each MD twin pair was significantly lower than that in each DD twin pair. CONCLUSIONS: The heart rate dynamics of healthy MD and DD twin fetuses becomes more chaotic according to gestational age. From the viewpoint of the FHR-regulating system, a pair of MD twins seems to have a more strict binding than a pair of DD twins before 30 weeks' gestation.

Feasibility of an AI-Based Measure of the Hand Motions of Expert and Novice Surgeons.

This study investigated whether parameters derived from hand motions of expert and novice surgeons accurately and objectively reflect laparoscopic surgical skill levels using an artificial intelligence system consisting of a three-layer chaos neural network. Sixty-seven surgeons (23 experts and 44 novices) performed a laparoscopic skill assessment task while their hand motions were recorded using a magnetic tracking sensor. Eight parameters evaluated as measures of skill in a previous study were used as inputs to the neural network. Optimization of the neural network was achieved after seven trials with a training dataset of 38 surgeons, with a correct judgment ratio of 0.99. The neural network that prospectively worked with the remaining 29 surgeons had a correct judgment rate of 79% for distinguishing between expert and novice surgeons. In conclusion, our artificial intelligence system distinguished between expert and novice surgeons among surgeons with unknown skill levels.