 Three, nine, two, five, four, six. Repeat. Uh, I don't remember. This is the Google Pixel 4. It has a 5.7 inch OLED display, a Snapdragon 855 processor, and it can track your pupils on a sub-millimeter level with a reported median error of 3.5%. Okay, this video isn't really about a three-year-old phone. If you want to watch that review, we did one. You can still check it out if you want to. This video is about the camera in this phone, however, and how researchers at UCSD are using it to do more than just unlock it with their face. Instead, they're seeing if it can measure your pupil size, which they hope could potentially screen for neurological diseases like Alzheimer's. This is all really interesting to me because when we talk about health and tech, usually the conversation is around newer devices like wearables, which not everyone has. So I wanted to find out more about this technology, which again is on an older phone, and exactly what other health monitoring can be done with the device you may already have. My name is Colin Barry. I'm a second year PhD student at UC San Diego in the Electrical and Computer Engineering department. And most of our work here is focused around using ubiquitous technology, so smartphones, wearables, and things that we already have around us to do health-based computation. So I'm just wondering how does pointing a smartphone camera in your eye tell you anything about neurological diseases like Alzheimer's? It can be difficult to understand why the eye would be a metric for different neurological diseases. And first, I guess to tell you a little bit about the measurement. That measurement is really just the size of your pupil. Now, if you don't know, the pupil is the dark center of your eye that expands and contracts. It's just like a camera iris that lets in more or less light depending on how wide the iris is open. But our pupils can tell more of a story than just how bright it is outside. So it's not just a quick snapshot of the eye. Actually, it's recording your response to specific tasks. These are correlated with neurological diseases because of the connections within the brain between certain brain regions associated mostly with fight or flight response. And so what the pupil is doing is basically giving scientists sort of a window into the brain and seeing how we can not basically identify different traits or different cognitive impairments by the dysfunction or the function of your pupil response. In other words, how your pupil responds to certain tasks can tell scientists a lot about your cognitive health. So how does this app allow them to do that? The way the app works is that it's going to be using the facial recognition system because it includes near-infrared cameras. So these cameras are recording in a non-visible range. It's not the same colors and things that we and you will see when we look around. And this is especially important for pupil measurements because some people have dark brown eyes because of the melanin in their eyes. And the difference between their black pupil and their dark iris is going to be very minimal in the visible spectrum. But when you look at it in the infrared spectrum, it's almost basically black and white between the two. And that's how we're able to get these submillimeter measurements of the pupil. There's actually a lot of work going on at UCSD when it comes to unlocking the technology in your smartphone for health applications. There's a huge sort of library of different measurements that you can take with a smartphone. And a lot of work needs to be done to have these measurements sort of validated and have them not only validated by themselves but validated across many smartphone models. Many smartphone models is a key point here too because not all smartphones have IR cameras. The Pixel actually lost them after the 4. Now, Viran and I aren't in the age demographic that Collins Research Group is studying, but he was still nice enough to lead us through our own pupil exams, which was pretty easy. For the most part. 6, 9, 1. If you need to blink now, repeat. 6, 9, 1, 7, 4, 2, 8. Maybe you should do it in creation. This is getting harder. So the app isn't designed to show us what it's recording. Collin collects the data and reads it back at the lab, which will look like this. A chart showing our pupil changing size over time and this somewhat creepy video of my eyeball. Now, if that doesn't seem like much, getting this information is actually pretty hard. So generally, the pupilometry measurements are done in clinical lab in very controlled settings with specialty devices called pupilometers. They can cost upwards of $9,000 or $10,000, which is a huge limiting factor, especially for a lot of clinics. Now, Collin isn't suggesting that your Pixel 4 is going to replace a $10,000 machine. There's still a long way to go to find out if this approach is accurate enough to be useful. What he is doing here is called a feasibility study. It's meant to figure out what could be possible. The vision is that hopefully people can use these smartphone-based measurements to have people take their measurements at home, outside of the clinic, and then the doctors can use that to understand whether they need to take more measurements in the clinic. That accessibility is important. Not everyone has access to a clinic with this machine. But a lot of people do have smartphones, which is good, but still not a perfect solution. Yeah, so smartphones are going to be more widely used than wearables, so you've got some potential for more access there. Nicole Weitzman is a health reporter here at The Verge who's covered tons of stories on the intersection of health care and technology. I think that digital divide issues are always going to be relevant when you're looking at adding health products to a digital device, because just because someone has a smartphone doesn't mean that they have the background and experience to be able to use it to the fullest extent of its capabilities. You see this happening with the telemedicine space during the pandemic. Just because someone has a computer in their home doesn't mean that they're going to be able to access a telehealth service. Maybe that's because they don't know how to download the application, or the application is not available in the language that they speak, or they don't have reliable internet access, or they don't have a quiet space to make that kind of happen. When we're meeting with participants, a lot of what we do is actually just explaining how to use the phone and what the technology is. We're explaining how to use the phone and how to touch on a touch screen, how to turn the phone on. This is something that Colin and Nicole are acutely aware of. There are a lot of health apps out there claiming to do a lot of things, but there's no guarantee that the public is going to know how to use them correctly. And some populations, they'll get left out of using them completely. That's why the type of research that Colin and other scientists do is important. This isn't about rushing to get the latest feature out on the newest flagship device. It's more about how do we take these pretty incredible devices that we already have and find out how much good we can do with them for the most people. Now, we'll still have to wait and see if Colin and his team's research pans out. And even if it does, that's not the end of the story. Like, does a company like Google decide to buy this research or recreate it? Or does this actually become developed as a legit clinical tool used by doctors in conjunction with traditional devices? They're both pretty intriguing options that could grant more access to more people. Yeah, I think that simplification of screening can be useful. You know, leveraging the technology at our disposal, you know, smartphones are really ubiquitous. And if those can have important health applications, then it's, you know, I think really useful to try to investigate that to the fullest extent that we can. Like, let's see what we can do with this. Huge thanks to Colin Barry from UCSD for sharing his research with us. They're doing really cool things over there with the tech that we use every day. And thanks to Nicole for giving us the greater context on healthcare in tech. Be sure to check out her writing on theverge.com. So, yeah. Pixel 4. Still impressing. Three years later. Not bad.