The VascuLens

A Handsfree Projector-Based Augmented Reality System for Surgical Guidance During DIEP Flap Harvest

Abstract

Augmented reality technologies are increasingly
being used to provide enhanced surgical navigation for
surgeons. The goal of such augmented reality technology is to
improve both the safety and efficiency of operations. The
VascuLens, a novel handsfree and focus free projector-based
augmented reality system, is presented in this paper. The
proposed application for the VascuLens is for improving
visualization of the vascular anatomy during deep inferior
epigastric perforator (DIEP) flap breast reconstruction. The
DIEP flap is a fasciocutaneous flap that is harvested based on
perforating vessels 1-2mm in size and then connected under
the microscope to the internal mammary vessels in the chest to
create a new breast mound after mastectomy. The VascuLens
system aims to take preoperative CT scan data, register the
preoperative data to the patient on the operating room table,
and project the segmented DIEP arteries directly onto the
patient. The novel aspects of the system include: 1) a handsfree
projector, 2) a simple preoperative to intraoperative image
registration technique that does not require a fiducial marker
or camera, 3) and intraoperative surgeon-in-the-loop surgical
guidance. This paper describes the proof-of-concept Vasculens
workflow and reports the Vasculens accuracy. The accuracy is
reported as a function of registration technique, patient body
type, projector height and projector angle. Using the ideal
registration technique, projector height and projector angle,
the mean absolute point reprojection error is 1.7mm, making it
a good candidate for DIEP flap breast reconstruction surgery.