A new, air-filled optical fiber bundle could dramatically improve medical endoscopes. This technology could also help create endoscopes that produce images using infrared wavelengths. If so, this breakthrough would allow diagnostic procedures that aren’t currently possible.
In the Optical Society (OSA) journal Optics Letters, University of Bath (U.K.) researchers showed that these new fiber optic bundles (called air-clad imaging fibers) deliver resolution equal to the best commercial imaging fibers. And the bundles do this at twice the wavelength range of these fibers. Because of this, these air-clad imaging fibers could help create new, smaller endoscopes with even better resolutions.
HOW ENDOSCOPES WORK
Used in minor surgery and imaging, endoscopes use bundles of optical fibers to obtain images from inside the body. Light that falls on one end of the fiber bundle travels through each fiber to the far end. This process sends a picture as thousands of spots, much like pixels in a digital picture.
TESTING THE BUNDLES
Instead of using cores and claddings of two types of glass, the new bundles use an array of glass cores covered by hollow glass capillaries filled with air. These air-filled capillaries act as the fiber cladding.
To test the imaging fibers, the research team created an air-clad fiber bundle. This bundle matched the resolution of a leading commercial fiber (with the same spacing between cores). The team then stacked multiple, smaller honeycomb structures to place more than 11,000 cores into the fiber.
The researchers used the air-clad fiber bundle and the commercial fiber to image a standard test target image. And the result? The air-clad fiber performed well beyond the wavelength range that a visible camera could detect. And when the researchers switched to an infrared camera, the fiber created a clear image at twice the wavelength that the commercial fiber reached.
REAL-WORLD USE OF FIBER BUNDLES
Along with medical diagnosis and care, the new optical fiber bundles could be used for industrial applications. These uses include monitoring the contents of hazardous machines and viewing the inside of oil and mineral drills. These types of fibers are becoming more and more popular for a variety of purposes.
OFS Laboratories, one of the world’s leading optical fiber research labs, and the research arm of OFS, has performed major work in this area. The development of Microstructure Optical Fibers (MOFs) is one result of this work. The MOFs created by OFS Labs are a new class of optical fibers that are substantially different from conventional optical fibers.
Placing sensors inside the human body can help researchers and physicians to understand and treat a variety of medical conditions. However, while implanting a sensing device may be routine, having it remain in the body long enough to perform its job and then be safely removed is an entirely different and significant challenge.
Now a team of Italian and Greek researchers have embedded fiber Bragg gratings, a type of device that reflects certain light wavelengths and can be used as a sensor, inside of dissolvable optical fibers. This new technology may allow the long-term monitoring of the biomechanical and chemical properties of various organs and anatomical features inside the body.
Fiber Bragg gratings placed into optical fibers are routinely used to measure stresses placed on bridges, commercial airliner wings and other areas where detailed, real-time monitoring is critical. The newly-developed fiber Bragg gratings are able to break down, similar to absorbable sutures and, because they have been embedded into optical fibers that are also bioresorbable, they should be safe for use inside the body. Ideally, they would be implanted, left inside the body to perform sensing and eventually disappear completely without the need for removal. (more…)
A new fiber optic technique for assessing muscle health could eliminate the need for painful muscle biopsies. To diagnose a muscular disorder, disease or infection, physicians must often extract a tissue sample. However, these biopsies can be quite painful and difficult to perform.
A story in Medical XPress reports that researchers at the Rehabilitation Institute of Chicago (RIC) have developed a less invasive alternative that uses a thin fiber optic probe to quickly scan and measure the health of muscle tissue. And, for the first time, the team has now tested the system on living muscle.
To read the article, please go here. To access the full report in Biophysical Medical, use this link. For information on OFS fiber solutions for medical devices, please click here.
Medical imaging faces limitations inherent to its mode of presentation. While computer models and virtual reality are much more effective than 2D depictions, the result continues to be still images on a computer screen. Even with stereoscopic techniques, a user’s ability to visualize the result can depend on using a keyboard or mouse to interpret the model. And, with 4D experimental medical data (such as MRI), objects are displayed as computer animations or static pictures.
A recent Biophotonics article by Thomas Britton and OFS’ Jaehan Kim shows how a hands-on, 3D-printed brain model equipped with optical fibers can help clinicians and patients to visualize brain function activity while avoiding the shortcomings of 4D neuroimaging techniques.
To access the full article, please click HERE.
OFS will showcase its new Shape Sensor Fiber at the BIOS/Photonics West Exposition in San Francisco, January 28-February 2, 2017.
To create the Shape Sensor Fiber, OFS developed a technology platform to produce high-quality, twisted multicore optical fiber with continuous Fiber Bragg Gratings (FBGs). This type of fiber with FBGs provides stable and good signal-to-noise ratio throughout the fiber length and ease of use to customers. The manufacturing platform also allows OFS to customize and optimize the fiber to meet various customer demands more economically. In addition, OFS also offers low back reflection distal termination, multicore connectorization and fan-outs to support customer demand.
Many medical device companies are developing cutting-edge endoscopes, catheters and other equipment with shape sensing technology to increase the quality of patient care. By embedding or surface-attaching the fiber to surgical tools or other devices, technicians can calculate and reconstruct the 3D shape of an instrument on a display screen. By allowing users to monitor the exact shape and position of the instrument, physicians can conduct minimally invasive surgery (MIS) or treatment which generally results in shorter recovery times, less pain and trauma, reduced rates of infection and shorter hospital stays.
In a recent study, researchers from the University Hospital Jean Minjoz (Besacon, France) demonstrated that optical coherence tomography (OCT) imaging can more readily visualize the coronary arteries in patients undergoing percutaneous coronary intervention (PCI) and lead to better outcomes when compared to standard angiography-guided PCI.
The study found that OCT provided useful additional information beyond that obtained solely by angiography, and impacted directly on physician decision-making. In fact, the use of OCT led to a change in procedural strategy in half of the cases.
In cardiology, the use of OCT involves introducing a miniature fiber optic catheter into the coronary artery to check vessel size, lesion traits and both stent positioning and expansion. OCT is also used in ophthalmology to assess the progression of macular degeneration, glaucoma and other ocular diseases.
To access details of the study, please go here and also here.
Different applications and optical fiber types present varying requirements for fiber coatings. When specialty optical fibers are used in demanding conditions, the fibers require coatings that are sustainable when subjected to harsh circumstances.
In fact, the successful deployment of fiber in these environments can often depend far more on the fiber’s protective external coating rather than its internal optical design. Fibers may be under attack from high and low temperature ranges, excessive humidity, high pressure, aggressive chemicals, mechanical interactions or any combination of these elements.
A recent OFS white paper in NASA Tech Briefs evaluates the stability of commercially available and in-house formulated, acrylate-based coatings to help determine the optimum coating for a range of conditions. To read more, please go HERE.
The physical characteristics of high-quality, silica optical fiber make it a natural choice for a broad range of uses, including many in the medical industry. For example, fiber can provide a very compact, flexible conduit for light or data delivery in equipment, surgical and instrumentation applications.
However, users must carefully choose the right optical fiber to avoid delays in product design and launch, along with increased development costs. A recent Medical Design Briefs article by OFS’ Jaehan Kim and Jonathan Loft explores the wide array of fibers available for this market. To access this article, please go HERE.
The commercial use of optical fiber in harsh environments is continually growing. These applications include medical probes that undergo sterilization at elevated temperatures and distributed sensors in oil and gas pipelines and wells exposed to extreme heat and cold. For these fibers to be used successfully, researchers and manufacturers must address the issues of fiber performance and reliability under the harshest conditions.
However, current theories and knowledge on the strength and dependability of silica-based optical fiber have been based almost exclusively on experiments conducted in optical telecommunications environments. Moreover, these tests only used a relatively narrow range of temperatures. For usage in extreme environments, fiber developers and users need new data and information.
In a recent white paper from OFS Specialty Photonics, researchers describe a setup for testing the tensile strength of optical fiber when exposed to high temperatures. This paper also reports the initial results of dynamic tensile strength testing conducted on polyimide-coated optical fiber at elevated temperatures over various time intervals.
To learn more and access this white paper, CLICK HERE.
OFS recently developed a technology platform to build high-quality, fiber optic probes with flexible tip lensing designs for Optical Coherence Tomography (OCT) medical imaging applications. These probes meet or exceed critical OCT specifications including insertion loss, internal back reflection, beam size and working distance.
With vertically integrated manufacturing, OFS offers a wide range of custom optical fibers including select cutoff, specific numerical apertures, graded index fibers and coreless fibers. Any OFS medical-grade optical fiber or cable can be paired with a connector or custom probe assembly for a turnkey, sterilizable sub-assembly, ready to plug in to a medical device.
Optical Coherence Tomography (OCT) is a medical imaging technique used to capture micrometer-resolution, three-dimensional images directly from sub-surface tissues. Physicians increasingly choose OCT for diagnostic use in ophthalmology, interventional cardiology and gastroenterology.
To learn more, please go HERE.