Rate of Orientation Change as a New Metric for Robot-Assisted and Open Surgical Skill Evaluation

Yarden Sharon, Anthony M. Jarc, Thomas S. Lendvay, Ilana Nisky

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Surgeons' technical skill directly impacts patient outcomes. To date, the angular motion of the instruments has been largely overlooked in objective skill evaluation. To fill this gap, we have developed metrics for surgical skill evaluation that are based on the orientation of surgical instruments. We tested our new metrics on two datasets with different conditions: (1) a dataset of experienced robotic surgeons and nonmedical users performing needle-driving on a dry lab model, and (2) a small dataset of suturing movements performed by surgeons training on a porcine model. We evaluated the performance of our new metrics (angular displacement and the rate of orientation change) alongside the performances of classical metrics (task time and path length). We calculated each metric on different segments of the movement. Our results highlighted the importance of segmentation rather than calculating the metrics on the entire movement. Our new metric, the rate of orientation change, showed statistically significant differences between experienced surgeons and nonmedical users / novice surgeons, which were consistent with the classical task time metric. The rate of orientation change captures technical aspects that are taught during surgeons' training, and together with classical metrics can lead to a more comprehensive discrimination of skills.

Original languageEnglish
Article number9404322
Pages (from-to)414-425
Number of pages12
JournalIEEE Transactions on Medical Robotics and Bionics
Issue number2
StatePublished - 1 May 2021


  • Medical robotics
  • human motion analysis
  • physical human-robot interaction
  • surgical robotics
  • surgical skill evaluation

ASJC Scopus subject areas

  • Control and Optimization
  • Artificial Intelligence
  • Human-Computer Interaction
  • Biomedical Engineering
  • Computer Science Applications


Dive into the research topics of 'Rate of Orientation Change as a New Metric for Robot-Assisted and Open Surgical Skill Evaluation'. Together they form a unique fingerprint.

Cite this