The Biophotonics and Bioengineering Laboratory, lead by Dr. Victor Yang, focuses on the use of optical imaging modalities for clinical translational research, with the overarching goal of merging biomedical engineering device development with clinical practice. The research group works closely with industry to achieve this goal. Specific areas of research include:
1) Optical topographical imaging (OTI) for surgical navigation:
This contribution has resulted in patent applications in PCT phase, for the method and apparatus for fiducial-less and reference-frame-less real-space surgical navigation, with applications in spinal, orthopedic, and neurosurgery. The prototypes developed in this research are tested at multiple hospitals for animal and cadaveric surgeries. The technology developed in this work may significantly change surgical navigation and potentially benefit patients undergoing spinal, orthopaedic, and neurosurgical procedures. Further, the same core technology is used by industry partner 7D Surgical.
2) Speckle variance and Doppler optical coherence tomography (SV-OCT and D-OCT):
With recent development in high speed and multi-channel OCT systems, we have introduced a computationally efficient method to image microvasculature based on temporal variations of speckle pattern in OCT images. The technique was applied to animals studies to provide detailed non-fluorophore based imaging of microcirculation. We are working with industry partner Michelson Diagnostics Ltd. who have created a clinical system for imaging using SV-OCT methods.
Figure 2: Development of OCT technology and instrumentation for preclinical and clinical research. (a) svOCT imaging of beneath tumor microvasculature in a window chamber model; (b) svOCT imaging of in vivo nailfold capillary; (c) histology of corresponding nailfold capillary in (b).
Presently, we are applying this technology to study Non-melanoma skin cancer treatment using photodynamic therapy in partnership with the Odette Cancer Centre.
See our latest paper on SV-OCT and DOCT here.
3) Photodynamic therapy for Non-melanoma skin cancer (NMSC):
Non-melanoma skin cancer (NMSC) is the most common cancer in Canada. Various treatment modalities exist including surgical excision, radiotherapy, topical therapies, electrocautery, and cryotherapy. The course of treatment is determined by the stage and location of disease, patient comorbidites and preference. For patients not eligible for surgery or disease locations where excision is cosmetically undesirable, radiotherapy (RT) or photodynamic therapy (PDT) is often recommended. The objective of this proposal is to establish precise three-dimensional imaging to visualize the extent of tumor burden on a submillimeter scale and decrease the volume of tissue irradiated. This would potentially reduce amount of tissue treated by decreasing the prescribed treatment depth and reducing peripheral margins surrounding the gross tumor volume.
4) Optical Coherence Tomography guided Laser Ablation for hard-tissue ablation:
Bone cutting in surgery is currently done using un-intelligent tools (i.e. drills, saws, etc.) that depend on the proficiency of the surgeon to prevent damage to underlying critical structures. This project focuses on the development of a robot-guided laser osteotome (bone cutter) with the use of inline optical coherence tomography (OCT) to precisely control the cutting depth in real-time. Through the use of optical tomographic imaging (OTI) that has already been developed to a mature standing, the system will include a novel method for the surgeon to identify arbitrary boney trajectories for desired cuts. It is hypothesized that such a system will increase the precision of bone cutting, decrease the amount of time needed to make cuts into sensitive boney structures and also address certain issues of unsuccessful uptake of lasers in modern medicine.
5) Endovascular Doppler optical coherence tomography:
Dr. Yang’s research group has used endovascular OCT as a vascular imaging tool to provide feedback for carotid artery stenting (Figure 1). Endovascular optical coherence tomography looks at stent placement and visualizes blood flow patterns that are the result of stent-related complications in the human carotid artery.
Figure 3: a) Structural OCT image of a stented carotid artery. Coagulated blood was artificially injected into the vessel and had attached to the stent struts (red arrows). b) The corresponding endovascular OCT image which visualizes Doppler phase contours that could be used to assess the carotid artery. Scale bar: 1 mm.
6) Stroke and Carotid Disease:
Recent advances in endovascular treatments have seen great advances in the past decade, making Endovascular thrombectomy an effective procedure to treat some ischemic stroke patients. At Sunnybrook, we have been working to improve the efficiency of these procedures, and to build on the work done in previous ESCAPE trials. We continue to optimize our workflow and treatments as we continue clinical trials in stroke treatment, as well as the general treatment of carotid disease. Moreover, the employment of our aforementioned ED-OCT is presently being used in clinical trials to evaluate the structure, morphology, and hemodynamics of this disease.
See our latest paper on our stroke research here.