October 25, 2017
Breakthrough eye imaging device could be a vision-saver
The smallest, lightest, high-resolution handheld probe for diagnosing eye conditions
At Duke University, with the help of OpticStudio software from Zemax, a graduate student and his team developed the first handheld probe that can image the front and back of the eye in 3D in rapid succession. It makes effective, sight-saving diagnoses possible for military, elderly, young children, and other patients.
Medical field personnel in Afghanistan, for example, see soldiers with eye injuries ranging from scratches to the front of the eye caused by a sandstorm to retinal detachment in the back of the eye caused by a blast. Understanding the full extent of an injury in the field and determining the best treatment path is essential, whether it’s eye drops or an airlift to a hospital.
A telemedicine research grant paves the way
With a specialty in optical and mechanical design for ophthalmic applications, Dr. Derek Nankivil has focused on the development of new types of noninvasive imaging methods for diagnosis and treatment of eye diseases and injuries. These methods include scanning laser ophthalmoscopy and swept-source optical coherence tomography, where the wavelength of the laser is swept in time. In handheld applications, these are important imaging modalities because they’re non-invasive, high speed, and high resolution.
Nankivil led the project to develop a handheld imaging device as a fifth-year PhD student studying biomedical engineering at the Duke University School of Engineering. Partnering with the Fitzpatrick Institute for Photonics and working under Professor Joseph Izatt, Nankivil received a telemedicine grant from the Department of Defense to develop a field-deployable diagnostic instrument for the eye. Since graduation, Dr. Nankivil now works in Research & Development at Johnson and Johnson Vision Care.
Challenge of creating a smaller, lighter design that is powerful and accurate
“In the development of any design or system, we start with design specs and determine the performance metrics that we want to satisfy. In our case, we wanted to rapidly, sequentially image both the front and back of the eye with a minimal delay in between each mode,” said Nankivil. “We wanted to include an iris camera to guide gross alignment with the eye, and we wanted the whole thing to be as light as possible. We set an upper limit of 900 grams—two pounds.”
“There were handheld probes before, but we built the first one that rapidly sequentially images both the front and back of the eye.”
How OpticStudio helped constrain manufacturing costs
After the laser and the scanner were selected, the team moved to the optical design. That’s where OpticStudio came in.
“We used OpticStudio to design this lens and to keep it small, while also constraining the cost. Using the software, I could keep adding more glass to continue to improve performance, and conduct analysis to look at the tradeoff between complexity of design and performance,” explained Nankivil.
The team designed multiple solutions in OpticStudio and determined the sweet spot between cost/complexity and performance. They were able to decide when to push for higher performance or tighter tolerances (and pay a higher price), and when performance was satisfactory at a lower tolerance.
Promising applications for use in many situations
The handheld probe was designed so that it can be used when a patient is lying down. This makes it possible to use on patients who cannot sit up or use a chin rest. Especially convenient for use in surgical applications, this technology holds great promise for improving diagnostics and vision outcomes.
Read more about how OpticStudio was used to develop this breakthrough handheld eye imaging device.
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