Functional brain connectivity related to surgical skill dexterity in physical and virtual simulation environments

Abstract

. Significance: Surgical simulators, both virtual and physical, are increasingly used as training tools for teaching and assessing surgical technical skills. However, the metrics used for assessment in these simulation environments are often subjective and inconsistent. Aim: We propose functional activation metrics, derived from brain imaging measurements, to objectively assess the correspondence between brain activation with surgical motor skills for subjects with varying degrees of surgical skill. Approach: Cortical activation based on changes in the oxygenated hemoglobin (HbO) of 36 subjects was measured using functional near-infrared spectroscopy at the prefrontal cortex (PFC), primary motor cortex, and supplementary motor area (SMA) due to their association with motor skill learning. Inter-regional functional connectivity metrics, namely, wavelet coherence (WCO) and wavelet phase coherence were derived from HbO changes to correlate brain activity to surgical motor skill levels objectively. Results: One-way multivariate analysis of variance found a statistically significant difference in the inter-regional WCO metrics for physical simulator based on Wilk’s Λ for expert versus novice, , . Partial eta squared effect size for the inter-regional WCO metrics was found to be highest between the central prefrontal cortex (CPFC) and SMA, CPFC-SMA ( ). Two-tailed Mann–Whitney U tests with a 95% confidence interval showed baseline equivalence and a statistically significant ( ) difference in the CPFC-SMA WPCO metrics for the physical simulator training group ( ) versus the untrained control group ( ) following training for 10 consecutive days in addition to the pretest and posttest days. Conclusion: We show that brain functional connectivity WCO metric corresponds to surgical motor skills in the laparoscopic physical simulators. Functional connectivity between the CPFC and the SMA is lower for subjects that exhibit expert surgical motor skills than untrained subjects in laparoscopic physical simulators.

Neuroimaging guided tES to facilitate complex laparoscopic surgical tasks – insights from functional near-infrared spectroscopy

“…Here, the executive control may operate as a unitary function [6]; however, the information flows within the functional sub-regions of PFC and their interactions with the secondary somatosensory areas [21] may be crucial that may be facilitated with tDCS. Therefore, our next step is to elucidate the evolution of interregional brain connectivity during the FLS suturing task where our prior work [15] identified functional brain connectivity related to surgical skill dexterity during FLS pattern cutting task. Our preliminary study was limited by a small number of subjects and "Colin27" digital brain atlas for head modeling; although, both ROAST and AtlasViewer allowed subjectspecific MRI-based head modeling [22] which will be applied in the future.…”

“…complex FLS suturing task with intracorporeal knot tying may require attentional control in the inferior frontal gyrus [12] and polymodal processing in the ventral premotor cortex [13], [14]. Since fNIRS has been shown feasible during surgical task performance [1], [15], we conducted a case series with two expert surgeons and four novice medical students to elucidate PFC activation during the FLS suturing task. The study was approved by the Institutional Review Board of the University at Buffalo.…”

Interhemispheric functional connectivity in the primary motor cortex distinguishes between training on a physical and a virtual surgical simulator

“…The optical probes or optodes held by a standard electroencephalography (EEG) cap (www.easycap.de) were mounted on the scalp of each participant by avoiding any hair in between the source/detector and the scalp. During the trial, the subjects were asked to perform the PC task, where the goal was to cut along the circular mark on a piece of gauze as accurately and as quickly as possible (details in our prior work [10]). After a baseline rest period of 1min, the trial was started and the maximum time provided for doing the PC task was 5 min.…”

“…Then, the conversion of optical density to changes in HbO2 concentrations with differential path-length factors of 6.4 (690nm) and 5.8 (830nm) based on our prior work [3]. The mean HbO2 changes for each brain region [9], LPFC, RPFC, LPMC, RPMC, SMA, from long separation channels (interoptode distance of 30-40mm) specific to the cortical activity in those regions was analyzed within neurovascular frequency band (0.01-0.07Hz) based on our prior work [10]. Short separation channels (inter-optode distance of 8mm) captured the systemic physiology originating from non-cortical superficial regions which was separately analyzed to investigate the effect of noise using the wavelet transform [16].…”

“…Therefore, modulation of interhemispheric inhibition of the M1 for bimanual coordination is expected during the PC task. Our prior work [10] investigated the brain functional connectivity based on wave-let coherence metrics for the following brain regions in right-handed subjects: left lateral prefrontal cortex, medial prefrontal cortex, right lateral prefrontal cortex, left medial primary motor cortex, and SMA, and found only in the case of FLS box trainer (not for virtual basic laparoscopic skills trainer: VBLaST) a correspondence to the surgical motor skills. Specifically, the partial eta squared effect size for the inter-regional magnitude-squared wavelet coherence metric between the medial prefrontal cortex and the SMA was found to be highest for expert versus novice comparison in the FLS box trainer cohort.…”