November 3, 2017
OCT for the People
[This article originally published on The Translational Scientist, November 2, 2017]
Can a low-cost OCT device aid biomedical research and improve disease diagnosis in rural and low-income settings?
At a Glance
- OCT is an effective tool for biomedical research and for the diagnosis of a range of retinal diseases – but it’s far from inexpensive
- A 3D printed approach can produce a portable OCT device for a fraction of the cost, helping to expand the reach of OCT
- There are drawbacks, such as the number of images you can take per second – but the device is still an effective diagnostic and imaging tool
- Working to democratize previously expensive medical equipment, such as OCT, ultimately brings better healthcare to all.
I’ve been working in the field of biomedical optics for 20 years and, in that time, I’ve brought a number of different products through clinical trials and to market – mostly endoscopes. In general, I’ve been frustrated with how expensive it is to bring a new medical product to market. By the time you’ve completed research and clinical trials, you end up with a device that could cost upwards of a hundred thousand dollars, and costing up to a thousand dollars per use. And that means that it’s very tough to get new technologies adopted. In short, we do a great deal of work, spend a lot of money, but end up with very few products that actually bring enough benefit to convince the market to buy them.
Coming from a physics background, I’ve always loved how optical approaches can provide very elegant and precise descriptions of scientific phenomena. Taking this technology and applying it to biology and medicine, a much messier field, is where the biggest challenges lie. Nevertheless, I was inspired to start a company with a different vision: to prove that we can create low-cost, high-quality biomedical imaging products, and still make a profit. Our first project? Optical coherence tomography (OCT).
An elegant – but expensive – approach
OCT is already an established technology with known benefits – it provides noninvasive, cross sectional imaging, and penetrates more deeply into tissue than confocal microscopy, without requiring a fluorescent reporter. Essentially, it’s an optical analog of ultrasound. In ultrasound, you send a pulse of sound into your sample, and wait for it to ‘bounce’ back. The time it takes tells you how deep it’s gone. With OCT you use light, which moves much more quickly – so you can’t just time it with an electronic stopwatch! Instead we do interferometry: we break some of the light off into a reference arm, send it down a reference path, and when that light comes back it’s matched with the light that has gone into the sample, giving you an interference pattern. By varying the length of the reference arm, you can map out a depth-resolved reflection profile from your sample. And you can get beautiful detail on all the cross sectional layers.
These benefits have led OCT to become the current gold standard in detecting diseases of the retina – it’s a great approach for detecting diseases like diabetic retinopathy, age-related macular degeneration (AMD), and glaucoma. The main problem is the expense of OCT systems, which means that they are more typically found in big eye centers; if you’re 100 miles away from the nearest city, you don’t have easy access to the technology. And if you’re in a low- or middle-income country, the problem is the same.
We set out to create a lower cost device to increase access to this imaging technology. The result is a device about the size of a shoebox that costs under $10,000, which essentially allows doctors to visit remote locations or perhaps a retirement home, where patients are less mobile, and scan 30 or 40 people in a single session.Read the full story