Optical Coherence Tomography (OCT) has extensive potential for producing clinical impact in the field of neurological
diseases. A neurosurgical OCT hand-held forward viewing probe in Bayonet shape has been developed. In this study,
we test the feasibility of integrating this imaging probe with modern navigation technology for guidance and monitoring
of skull base surgery. Cadaver heads were used to simulate relevant surgical approaches for treatment of sellar,
parasellar and skull base pathology. A high-resolution 3D CT scan was performed on the cadaver head to provide
baseline data for navigation. The cadaver head was mounted on existing 3- or 4-point fixation systems. Tracking markers
were attached to the OCT probe and the surgeon-probe-OCT interface was calibrated. 2D OCT images were shown in
real time together with the optical tracking images to the surgeon during surgery. The intraoperative video and
multimodality imaging data set, consisting of real time OCT images, OCT probe location registered to neurosurgical
navigation were assessed. The integration of intraoperative OCT imaging with navigation technology provides the
surgeon with updated image information, which is important to deal with tissue shifts and deformations during surgery.
Preliminary results demonstrate that the clinical neurosurgical navigation system can provide the hand held OCT probe
gross anatomical localization. The near-histological imaging resolution of intraoperative OCT can improve the
identification of microstructural/morphology differences. The OCT imaging data, combined with the neurosurgical
navigation tracking has the potential to improve image interpretation, precision and accuracy of the therapeutic
This study presents the design of a system used to monitor laser ablation in real-time using Optical Coherence Tomography (OCT). The design of the system involves a high-powered fiber laser (wavelength of 1064nm, 1kW peak power) being built directly into the sample arm of the OCT system (center wavelength 1310). It is shown that the OCT laser light and subsequent backscatter pass relatively unaffected through the fiber laser. Initial results are presented showing monitoring of the ablation process at a single point in real time using m-mode imaging.
The use of gas assistance in laser machining hard materials is well established in manufacturing but not in the context of surgery. Laser cutting of osseous tissue in the context of neurosurgery can benefit from gas-assist but requires an understanding of flow and pressure effects to minimize neural tissue damage. In this study we acquire volumetric flow rates through a gas nozzle on the spinal cord, with dura and without dura.
Carotid atherosclerosis is a critical medical concern that can lead to ischemic stroke. Local hemodynamic patterns
have also been associated with the development of atherosclerosis, particularly in regions with disturbed flow
patterns such as bifurcations. Traditionally, this disease was treated using carotid endarterectomy, however
recently there is an increasing trend of carotid artery stenting due to its minimally invasive nature. It is well
known that this interventional technique creates changes in vasculature geometry and hemodynamic patterns
due to the interaction of stent struts with arterial lumen, and is associated with complications such as distal
emboli and restenosis. Currently, there is no standard imaging technique to evaluate regional hemodynamic
patterns found in stented vessels.
Doppler optical coherence tomography (DOCT) provides an opportunity to identify in vivo hemodynamic
changes in vasculature using high-resolution imaging. In this study, blood flow profiles were examined at the
bifurcation junction in the internal carotid artery (ICA) in a porcine model following stent deployment. Doppler
imaging was further conducted using pulsatile flow in a phantom model, and then compared to computational
fluid dynamics (CFD) simulation of a virtual bifurcation to assist with the interpretation of emphin vivo results.
This paper presents the development of a compact, desktop laser-cutting system capable of cutting materials such as wood, metal and plastic. A re-commissioned beheaded MakerBot® Replicator 2X is turned into a 3-DOF laser cutter by way of integration with 800W (peak power) fiber laser. Special attention is paid to tear-down, modification and integration of the objective lens in place of the print head. Example cuts in wood and metal will be presented, as well as design of an exhaust system.