The Public Domain is a credit.
The method for increasing the depth at which optical coherence tomography can image structures beneath skin was demonstrated by Duke University.
The gold standard for using OCT as an alternative to conventional x-rays for other parts of the body is due to its inability to return clear images from more than a millimeter beneath the skin's surface.
Duke researchers found that using a light source and detector that is tilted increases the depth of the OCT's images by almost 50%. The dual-axis approach opens new possibilities for OCT to be used in applications such as spotting skin cancer, assessing burn damage and healing progress, and guiding surgical procedures.
The results are online on December 1 in the journal.
"It's a fairly simple technique that sounds like something out of Ghostbusters," said Adam Wax, professor of biomedical engineering at Duke. There are a lot of biological processes happening at that depth that can be indicative of diseases like skin cancer.
Standard OCT uses light instead of sound. By measuring how long it takes for a beam of light to bounce back, computers can deduce what the internal structure of the object looks like. The thin and transparent eye's lens and cornea make it easy to see the thin and thin retina.
It is difficult to penetrate with standard OCT approaches because most other biological tissues scatter and reflect light. The deeper the light goes, the more likely it is to miss the device.
The researchers point the light at the object at a slight angle and set up the detector at an equal and opposite angle. The slight scattering angle introduced by the object's physical nature allows the detector to benefit.
Evan Jelly, a PhD student in Wax's laboratory, is the first author of the paper. Just a little bit more of that scattered light is all you need.
Jelly says that researchers have tried this dual-axis approach. Jelly discovered how to apply this to OCT. His discovery was that the depth of the focal point of light within the tissue is a big factor in how well the dual-axis approach works.
The larger the angle used to identify deeper signal, the smaller the field of view becomes. Jelly devised a method of scanning the focus of the narrower window through various depths of the tissue and then using a computation to combine the data into a single image.
In the paper, Wax and Jelly tested this approach with fake tissues and hairless mice to see what information it could reveal in a live animal's skin. The dual-axis approach tends to perform better than the standard setup. In the live mice, the dual-axis OCT was able to image the tip of a needle 2 millimeters beneath the skin's surface, where 1.2 millimeters is traditionally the landmark depth.
Jelly said that the dual-axis OCT gave them images and information from the layers of skin where blood and molecular exchanges are occurring, which is extremely valuable for detecting signs of diseases. The technology is still in its infancy, but it is poised to be very successful for guiding surgical procedures.
Evan T. Jelly and his team have a paper on Deep image with 13 m dual- axis optical coherence tomography and an enhanced depth of focus. There is a book titled "10364/BoE.438621."
The journal has information about the Biomedical Optics Express.
The news about eye technology breaking through skin was retrieved from thephys.org.
The document is copyrighted. Any fair dealing for the purpose of private study or research cannot be reproduced without written permission. The content is not intended to be used for anything other than information purposes.
