Brain activation in parietal area during manipulation with a surgical robot simulator

Purpose: we present an evaluation method to qualify the embodiment caused by the physical difference between master–slave surgical robots by measuring the activation of the intraparietal sulcus in the user’s brain activity during surgical robot manipulation. We show the change of embodiment based on the change of the optical axis-to-target view angle in the surgical simulator to change the manipulator’s appearance in the monitor in terms of hand–eye coordination. The objective is to explore the change of brain activation according to the change of the optical axis-to-target view angle. Methods: In the experiments, we used a functional near-infrared spectroscopic topography (f-NIRS) brain imaging device to measure the brain activity of the seven subjects while they moved the hand controller to insert a curved needle into a target using the manipulator in a surgical simulator. The experiment was carried out several times with a variety of optical axis-to-target view angles. Results: Some participants showed a significant peak (P value = 0.037, F-number = 2.841) when the optical axis-to-target view angle was (Formula Presented.). Conclusions: The positional relationship between the manipulators and endoscope at (Formula Presented.) would be the closest to the human physical relationship between the hands and eyes.