Objective assessment of surgical skill transfer using non-invasive brain imaging



Physical and virtual surgical simulators are increasingly being used in training technical surgical skills. However, metrics such as completion time or subjective performance checklists often show poor correlation to transfer of skills into clinical settings. We hypothesize that non-invasive brain imaging can objectively differentiate and classify surgical skill transfer, with higher accuracy than established metrics, for subjects based on motor skill levels.

Study design

18 medical students at University at Buffalo were randomly assigned into control, physical surgical trainer, or virtual trainer groups. Training groups practiced a surgical technical task on respective simulators for 12 consecutive days. To measure skill transfer post-training, all subjects performed the technical task in an ex-vivo environment. Cortical activation was measured using functional near-infrared spectroscopy (fNIRS) in the prefrontal cortex, primary motor cortex, and supplementary motor area, due to their direct impact on motor skill learning.


Classification between simulator trained and untrained subjects based on traditional metrics is poor, where misclassification errors range from 20 to 41%. Conversely, fNIRS metrics can successfully classify physical or virtual trained subjects from untrained subjects with misclassification errors of 2.2% and 8.9%, respectively. More importantly, untrained subjects are successfully classified from physical or virtual simulator trained subjects with misclassification errors of 2.7% and 9.1%, respectively.


fNIRS metrics are significantly more accurate than current established metrics in classifying different levels of surgical motor skill transfer. Our approach brings robustness, objectivity, and accuracy in validating the effectiveness of future surgical trainers in translating surgical skills to clinically relevant environments.

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The authors would like to thank the medical student subjects and their dedication for this study. The authors would also like to thank the anatomical gift program and the gross anatomy lab at University at Buffalo for their support regarding the ex-vivo cadaveric samples. We would also like to thank Arthur “Buzz” DiMartino and his team at TechEn in graciously providing us support with the CW6 spectrometer.


This work is supported by NIBIB 1R01EB014305, NHBLI 1R01HL119248, and NCI 1R01CA197491 grants that were awarded to Suvranu De.

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Correspondence to Suvranu De.

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Drs. Arun Nemani, Uwe Kruger, Meryem Yucel, Clairice Cooper, Steven Schwaitzberg, Xavier Intes, and Suvranu De have no conflicts of interest or financial ties to disclose.

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Presented at ACS Clinical Congress 2017, San Diego, CA.

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Nemani, A., Kruger, U., Cooper, C.A. et al. Objective assessment of surgical skill transfer using non-invasive brain imaging. Surg Endosc 33, 2485–2494 (2019). https://doi.org/10.1007/s00464-018-6535-z

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  • Surgical skill assessment
  • Surgical skill transfer
  • Brain imaging
  • Surgical simulators
  • Surgical training
  • Functional near-infrared spectroscopy