ARTEMIS
Augmented Reality Technology Enhancement for Minimally Invasive Surgery
As medical imaging systems continue to provide increasingly more sophisticated three-dimensional data sets, augmented reality technologies strive to make this data viewable directly within the area of intervention. The goal of ARTEMIS is to provide an ergonomic intraoperative system for visualizing anatomical data and real-time instrument location data superimposed on the real view of the patient.
System Design
ARTEMIS implements augmented image projection using a semi-transparent mirror to reflect a stereo image from a standard workstation monitor. The workstation renders a polygonal model constructed from CT or MRI data while the physician views the model through LCD shutter glasses. Fiducial markers on the patient’s skin are used to register the computer model with the patient. Tracking of the shutter glasses allows the virtual scene to be updated as the viewer’s head moves.
Needle-tracking is achieved using a unique fiber optic cable system designed by Luna Innovations. Extending along the entire length of the needle, this high spatial resolution, shape and position sensing fiber provides real time feedback of its shape and position in 3D space. The data is used to render the location and trajectory of the flexible needle in the same scene as the virtual patient anatomy. Knowledge of the needle shape and tip location inside the patient's body assists in planning a trajectory that reaches the target area while avoiding vital structures.
Demonstrator
Several key components of the ARTEMIS design have been implemented in a demonstration and test apparatus. The demonstrator includes the optical see-through window, visualization hardware and software, fixed stereo shutter glasses and a prototype needle-tracker. The apparatus has been used to render and overlay polygonal data sets created from MRI scans of phantoms (test objects), with the virtual needle drawn in the same scene. The prototype needle tracking system consists of a bare, tracked fiber whose base is attached to a fiducial marker located near the phantom.
The Future of ARTEMIS
The planned ARTEMIS prototype adds a number of improvements to the demonstrator:
- The bare tracked fiber will be attached to an RF needle or catheter.
- An ergonomic boom structure will facilitate deployment in the operating room.
- Tracked shutter glasses will compensate the rendered images for motion of the viewer.
- Flat-panel display technology capable of stereo rendering will reduce the size of the monitor-mirror hardware.
- Methods of compensating for organ displacements due to breathing will be tested.
