Optical Coherence Tomography - OCT
Product Announcement from Raytheon ELCAN Optical Technologies
Optical Coherence Tomography (OCT) is on the cutting-edge of medical technology and poised to become a valuable diagnostic tool in the next decade. Although the principles of OCT are increasingly applied for ophthalmologic examination, much work remains to apply this photonic technology toward new applications. When that happens, ELCAN Optical Technologies will be a pivotal partner to turn brilliant theory into innovative medical devices.
OCT combines the principles of ultrasound with the imaging performance of a microscope. While ultrasound produces images from backscattered sound "echoes", OCT uses IR light waves that reflect off the internal microstructures within biological tissues. The frequency and bandwidth of IR light are orders of magnitude higher than medical ultrasound signals, which increase image resolution by 8-25x. OCT is simple and painless, produces high-resolution real-time cross-sectional or 3-D images and is lower cost than imaging modalities that incorporate ionizing radiation, high magnetic fields or radioactive agents.
OCT utilizes a broadband light source (superluminescent diode, femtosecond lasers or white light with lower powers) to generate infrared light waves. Theses light waves are then split; one of the waves is aimed at the specimen and the other at a reference mirror. The reflected light is recombined and the resulting interference pattern is measured to determine the refractive index at different depths of tissue. These differences are indicative of the material properties of the specimen and can be used to determine whether or not the tissue is healthy.
Currently, the most common use of OCT is in ophthalmology, where structural changes within the layers of the retina, indicative of macular and retinal degeneration are monitored. OCT is however also demonstrating incredible promise in both diagnosis and treatment of the leading causes of death in North America - heart disease and cancer. Modern disease states, such as heart disease, Multiple Sclerosis and epithelial malignancies, demonstrate the limitations of traditional imaging techniques such as MRI, x-ray, ultrasound and nuclear imaging. Scientists, physicians and researchers are increasingly abandoning conventional imaging for Optical Coherence Tomography due to its near histological resolution without the need for excision or processing of the specimen.
Unstable plaques in the cardiovascular system may be responsible for up to 70% of all heart attacks (myocardial infarction). In vivo atherosclerotic plaque identification is possible with OCT and may make preventative treatment more effective and ultimately reduce fatalities. Stenting, balloon angioplasty and atrial fibrillation are also being aided by the real-time, high-resolution images obtained with OCT.
It is estimated that 85% of all cancers originate in the epithelium. Excisional biopsy methods remove random tissue samples that are examined under a microscope for cancerous cells. OCT assisted biopsies would provide real-time, in vivo location and confirmation of cancerous cells due to the resolution capabilities. Specific, targeted treatments could be exacted at the same time.
Multiple Sclerosis is caused by destruction of the myelin sheath covering nerve fibers in the central nervous system (brain and spinal cord). The retinal nerve fiber layer (RNFL) is the one part of the brain where nerve cells are not covered with a myelin sheath. Direct correlation has been established between the RNFL thickness and brain atrophy characteristic of MS. Measuring the RNFL tracks disease progression and allows for earlier and targeted treatments leading to a reduction in the advancement of the disease. While MRI (the traditional choice for imaging in MS) measures the result of many types of tissue loss, OCT images the nerve damage itself at roughly 1/10th the cost and in a matter of minutes rather than hours.
Optic nerve damage is not a unique diagnostic indicator for MS, but since this damage is one of the first evident symptoms of MS can be instrumental in early detection and commencement of treatment. While treatments for MS cannot reverse the neurological damage, they can slow the progression of the disease. OCT imaging may also be a useful tool in measuring the efficacy of neuroprotective drugs.
Blood glucose monitoring is cornerstone to management of diabetes, but is often neglected due to pain and inconvenience. Preliminary research demonstrates that non-invasive blood glucose monitoring is possible in diabetes patients with OCT. Constant non-invasive monitoring will result in better maintenance of the disease state and better long-term prognosis for diabetic patients.
ELCAN Optical Technologies (http://www.ELCANmedical.com/ ) works with customers seeking to design new optical systems in medical diagnostics, digital imaging and advanced sensing applications. We can provide optical, mechanical design and co-engineering to speed your idea to market. ELCAN's end-to-end contract manufacturing takes your idea from initial design and custom prototyping, through to cost-efficient high-volume production.
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