We have developed a multispectral imaging technique for identifying chemical compounds in vivo in the retina with cellular-level resolution and without the use of contrast agents. We combined simultaneous multi-channels offset and confocal AO-SLO imaging, which provides isotropic images of retinal microstructures free of directionality artifacts, with spectral signature analysis of chemical compounds to identify such biomarkers at cellular-level. The new concept has been demonstrated in a model eye using commercially available Aβ. An animal study on a mouse Alzheimer’s model is ongoing. This technique may pave a path forward for better understanding of the onset of various neurodegenerative diseases.
A smart optical probe that enables in vivo tissue type identification and the measurement of the force applied to the needle during epidural procedures is presented. This probe is meant to reduce the adverse risk associated with needle misplacement. It combines a Bragg sensor with low coherence interferometry (LCI) to measure the force applied by the operator on the standard epidural needle and differentiate tissue type presented at the tip of the epidural needle. The probe enables differentiation between different layers of tissue in the spinal region by making use of a machine-learning algorithm, which was trained on animal spinal cord tissue specimens.
Physical Sciences Inc. (PSI) is developing a sensitive, rugged, person-portable, and safe instrument for the quick analysis of metals in jet fuels in fuel depots and transfer stations. The instrument fills a needed role for easy and affordable analysis of catalyzing metals content in fuel batches before they are used in, or shipped to, critical engines such as military aviation platforms. The instrument targets a panel of most likely and problematic metals that are often found in kerosene-based fuels, both refined and synthetic. The cause for concern lies in the potential for many metals, even at part per billion (ppb) concentrations, to catalyze rapid degradation of fuel performance, especially at elevated storage temperatures. The laser-induced breakdown spectroscopy (LIBS) technology development reported here has demonstrated a robust and viable measurement system for multiple contaminants of importance to military (and commercial) fuel distribution. Estimated detection limits for all elements of interest, save phosphorus, are at sub-ppm levels. Signal normalization with an added internal reference has demonstrated an adjusted concentration measurement accuracy <95% and useful operation of the method near the noise floor of the instrument. The accomplishments are strong indicators for commercial potential for the technology as a useful tool in the intended fuel monitoring application, as well as other industrial sample analysis needs.
KEYWORDS: Optical coherence tomography, Pathology, Cancer, Tumor growth modeling, Tissues, Tissue optics, Position sensors, In vivo imaging, Data processing, Birefringence
Real-time assessment of tissue morphology and function is a pressing clinical need. We present a low cost OCT probe based on combined position sensor feedback, as well as a data processing algorithm that enables real-time display of tissue morphology and birefringence. The preliminary evaluation of this instrument on various biological specimens has demonstrated its capability for real-time diagnosis. Its preclinical assessment in vivo on animal models of cancer was performed at MD Anderson Cancer Center. Reliable assessment of tissue morphology and birefringence has been successfully demonstrated.
In this paper we report the use of a novel multimodal imaging hand-held probe for guiding laser and radiotherapy on nonmelanoma skin cancers (NMSCs) patients. This probe combines the capability of reflectance confocal microscopy (RCM) with that of Optical Coherence Tomography (OCT) to reliably detect cancer markers and measure cancer depth of invasion. These capabilities have shown to be very effective in accurately measuring cancer margins and guiding the therapy.
Sensorineural hearing loss (SNHL) is the most common sensory problem that causes permanent hearing loss due to the damage of cochlear hair cells. Current clinical imaging techniques do not provide sufficient resolution and functional assessment of the intracochlear structures. We developed a dual-mode endoscopic system that combines optical coherence tomography and autofluorescence to visualize the morphology and biochemical changes of the intracochlear structures. The preclinical assessment of the system was performed in a ovine model of SNHL in vivo. The preliminary results suggest that this approach may provide more accurate diagnosis of cochlear pathology and enable targeted SNHL therapies.
We report the development and the pre-clinical testing of a manual scanning OCT-based probe for core needle biopsy guidance. While stereotactic radiography, ultrasound, computed tomography, and magnetic resonance imaging are used to guide needle placement within a tumor, the optical probe provides the radiologist with the capability to examine tissue cellularity at the tip of the biopsy needle. The capability to investigate tissue cellularity prior to taking the biopsy could help reduce the number of non-diagnostic biopsies and increase the amount of viable tumor tissue within the biopsy core. This last aspect is very important in the new era of personalized cancer therapy, because greater tissue quantity is needed for various biomarker assays. This technology has been evaluated by us on a rabbit model of soft tissue cancer. Our results indicate the capability of this OCT-based probe for determining the in situ cellularity of the tissue at the tip of the biopsy needle.
Identification of positive margins during breast cancer conserving surgery is crucial for successful tumor resection. To address this clinical need, we developed a microscope that combines fluorescent microscopy, optical coherence tomography (OCT), and reflectance confocal microscopy (RCM) to identify the presence of positive tumor margins in surgical specimens. A cancer-targeting fluorescent agent is used to highlight potentially positive margins and guide combined RCM/OCT imaging. Combined RCM/OCT is used to accurately determine the extent of the positive margins, aided by custom image-processing techniques. This instrument has the potential to provide tumor margin guidance in the surgical suite, reducing reliance on lengthy histopathological inquiry and reducing the need for repeated surgery.
KEYWORDS: Ear, Optical coherence tomography, Endoscopy, Auto-fluorescence imaging, In vivo imaging, Magnetic resonance imaging, Pathology, Visualization, Sensors, Bone
This study presents a novel technology for in vivo cochlear imaging in sensorineural hearing loss (SNHL). SNHL is the most common type of permanent hearing loss and is associated with damaged hair cells of the cochlea. State of the art clinical imaging does not have sufficient resolution to show inner ear microstructure. We are developing and testing a dual-modal endoscopic instrument that combines optical coherence tomography (OCT) and autofluorescence imaging (AFI) for dynamic cochlear imaging. If successful, this approach will improve our understanding of the cellular basis of SNHL and enable the development of targeted therapies for inner ear disorders.
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