So we're going to switch from navigation to talking about some other technologies. The technology is in the back of the room. There's two of them are exoscopes. And so I'm going to bring up my colleague, Dr. Peter Grunert, who's going to give a short lecture on reviewing of how exoscopes help spine surgery. And then we'll have two demonstrations in the back there. First we'll have a synaptive, and then we'll have the VTOM by Stortz, and then we'll have a break before the robotic section starts. Okay. So hi. My name is Peter Grunert. I'm attending neurosurgeon work at Washington State with Dr. Drazen. We have a more focused, like, minimally invasive spine practice. And I did my fellowship at Swedish, and we had the opportunity there to just use a lot of new devices, new technologies. One of them were exoscopes, so I'm going to talk a little bit about that. So what is an exoscope? Basically, an endoscope is a camera within the body. An exoscope is a camera outside of the body. And if you would ask me two main reasons why exoscopes are beneficial, so I would definitely say the number one reason is pure ergonomics. And we all know these images from our ORs, you know, it's very difficult to operate with loops or with a microscope. You have to bend over, twist, and not everybody can see everything. You get, you know, some people get neck pain and back pain from it. It's not a very comfortable position to work on. Not everybody can see everything. And when you have a, when you work with an exoscope, it kind of like looks like this, you know, there's a lot of space in the OR. And, you know, around you, you have a huge working field. Everybody can stand up straight, and everybody sees the same thing. You have a huge screen, and everybody sees what the surgeon is doing. So it's very, very comfortable to work with for everybody in the OR. And it doesn't require a lot of space, very easy to get instruments in and out. Now the second important reason for me is the optical reason. And that's because the depth of field is much bigger when you use exoscopes versus a microscope. That has something to do with physics. It's a numeric aperture of, of lenses for microscopes. So the higher the magnification, the smaller the depth of field. And with exoscopes, because you look at everything as a, on a huge screen, and we'll see this later on over there, it just, you don't need the, you don't need so much magnification to see a big image. It's just because you're looking at a huge screen. And I give you an example here. This is a view, you know, from an aneurysm clipping, and you can just see through an exoscope, you see the whole field. The depth of field is much, much bigger, and you have better control of surrounding structures than with a microscope. You always have to zoom in and out. Here's a spine surgical example. You have an ACDF here. On the left, you see, this is through an exoscope, you see the disc, you see the disc fragments, you see the bone, versus with a microscope, it's kind of tough to see everything. Now one of the early ones was from a German company, the VITAM, from Storz. Um, and the first publication on this also came out of Germany. Here's a paper, um, where it described just their initial experience. And you can see here, the surgeon sits very comfortable doing spine surgery. They came up with, you know, they, they concluded it's, it's, it's very effective, less bulky, and it should be integrated, you know, for training purposes. And why do we have to integrate it for training purposes? Because you have to really learn how to use it. And, you know, this is from that paper, and it showed it is a little bit more time consuming. You have to learn how to use it, and that was kind of like also my experience when I started using it. Um, it's just, you have to get used to not look through a microscope and not look through loops. It's just a different, a very different experience. The other thing is because most of them, the, you know, the earlier ones, they were, they had no stereoscopic image, so you have to get used to the two-dimensional working. So that's why it's taking a while, and you just have to get used to it. Um, here's a paper from Dr. Drazen's group, um, from Cedars-Sinai, and they, they looked at it too for spine surgery. They were actually very happy using it, also for training purposes. Um, they, what they pointed out is the cost. The costs were much lower than for a microscope, and, but the magnification was great. They were very happy in using it. However, what they criticized in this paper is that the scope holder is a little bit of a problem. So we used to, you know, take the microscope and then just move it around. That was a little difficult with a scope holder that just holds the exoscope like this, because you always have to grab it and move it around so you get different angles. So there's a company that we actually have here, Synaptive, and they, they came up with a solution where they basically have a, a optoelectronic robotic visualization system. So basically what that means, and we'll be able to demonstrate that later, is that the, the camera, the exoscopes basically aligns with your, uh, field or what you want to see. So you have a pointer just like you have it for, for, you know, what we use for navigation, and that robot basically moves along with the, with the probe wherever you want to, you know, look at. And you can also save certain, um, trajectories, and it can come in and out and save such a trajectory. Um, and I think, you know, in general, this is kind of like where the future of these cameras is going, because these are not just going to be cameras outside of a body. I think they're going to be integrated, integrative devices. Like, we use navigation with this, and then, you know, and I'll show you an image later where you can measure, for example, fluorescence, because it's a digital image. So for five ALA patients, for example, you can actually measure how much fluorescence you have. We actually, um, this is a paper from my time at Swedish, and we looked at that, and we tested in cadavers, and it was very easy to use. It was, it was great for teaching, because everybody can see everything. And here's a paper where they actually looked into using exoscopes, um, um, for, uh, glioma resection, so it's not just for spine. And here's one of the advantages where I think in the future you will be able to measure five ALA fluorescence, and then you will be able to quantify during surgery. I think this is going to be something, um, that is going to have a big benefit. Uh, here's another, uh, paper from Dr. Dresen's group in Cedars-Sinai. They looked at not just spine surgery, but also for more complex brain surgery, especially pineal tumor surgery, and pineal tumors are very difficult to position, you know, and the way you sit, it's not very comfortable, you know, you have to like really go down and look up with a microscope. So as you can see here, the, the setup in the operating room is very, very comfortable. So for them, in that paper, what they said the drawback, especially for these kinds of surgeries, you know, where you have to, it's a very, uh, delicate tissue resection, is the, the drawback is definitely the start of stereoscopic vision. That's something that they pointed out. Um, so the stereoscopic vision is an issue when you start working with it, and there are actually this discussion, they had this discussion, um, you know, a while ago, especially for ENT because they use a lot of endoscopes, and you know, they actually conclude, there's a paper where they actually concluded that, um, using, uh, just using monocular vision with an endoscope actually has some benef- has some, um, also some benefits. It's not just, if you know the structures, basically, you can help to navigate around with an endoscope, and you can get used to, uh, two-dimensional, um, you know, image. However, it requires training, and it requires you to know the anatomy. So it's very difficult as a beginner to start operating in a two-dimensional, with a two-dimensional view. Um, there's actually a study that I found here that actually looked into this, how do you train, um, you know, like vis- uh, vis- uh, motor tasks, um, vers- and they looked into binocular or monocular vision, and they actually concluded, like, if you have haptic feedback, it improves it, you can do it, and this is kind of like, if you start to use, um, a 2D, um, exoscope, what we learned to do is just, like, by just haptic feedback, just touching the structures, it would help you to orientate yourself. Um, however, and this is what they concluded here, for training purposes, it's definitely better to have a three-dimensional image. And, um, you know, if Hollywood has done it, I mean, we watch movies in 3D now, so the question is, why don't we incorporate that into our OR, right? And, um, just before I get into 3D exoscopes, I just wanted to, like, point out these two words, um, so stereopsis, so that's how we see a three-dimensional space with our two eyes, because our two eyes are, you know, separate from each other, so that allows us to have a, uh, three-dimensional view. Um, a stereoscopic image is different, that's what we see, like, when we go watch a movie in 3D, that's basically artificially presenting two images to each eye separately, and that's how we get a 3D view, but it's, it's not a, it's not a real 3D view. And the way we do it in the OR nowadays is basically very simple, uh, very similar to how Hollywood does it, right? So we have two cameras, and then we project the images on one screen from these two cameras, and what it is, it's polarized light, that basically means that there's two, uh, wave orientations, one is horizontal and one is vertical, and when you put those glasses on, those polarized glasses, what it does is one glass only allows vertical aligned, um, um, waves to go through, and the other one only allows horizontal, so each eye only sees one of those overlying pictures. That's how it works. And that's exactly how it works in the OR. So here's a, uh, VITAM 3D exoscope, um, I think that came out in 2016, uh, and you can see here, you have two cameras, and then you have those polarized glasses, and that allows you to see these two images that are projected on the screen. And there's groups in Germany that already looked into this, here's a paper from, um, from a group from Hamburg, and they actually really liked it as a teaching tool, depth perception, they really liked it, and they had good experience with it, and they had really good, they reported really high, um, um, image quality, here's another paper from a German group, what they concluded is that there was more magnification potential with these 3D exoscopes, however the quality got worse in higher magnification. And, uh, that has something to do with the resolution, and the next generation kind of solves that problem, and I'll talk about this in the next slides. Um, what they also said is the illumination is better with microscopes, now why is the illumination better? That is just pure physics, it's because what I explained before is it's polarized light, and basically one eye is filtering out the other polarization, so it's not gonna be as bright, right, because if you look through a microscope you see the entire reflection of light, okay? Um, but they were very comfortable using it, and it was a great teaching tool. So the next generation, there's just papers coming out, uh, this year, and some, and also in, uh, late 2017, where they looked into clinical application for high definition, um, 3D exoscopes, so that's like the latest and newest generation, and, um, also they reported, um, they reported it to be a great tool, great asset in the OR, here I think is a great graph where they compared the 3D, um, high definition exoscope to a microscope, and I think what's very interesting here, you can see the illumination is definitely better with a microscope, but again, that's pure physics, but what they, what they also said is that the image definition is similar, it's more user friendly to use exoscopes, the accessibility of the surgical field obviously is better, and then the work environment ergonomics obviously is also better, but the illumination is better with a microscope, and that's very difficult to overcome. Here's another paper using, uh, high definition 3D exoscopes, and I think this is just a great example, it just shows you that, you know, if you do, if you do that dissection in a posterior fossa, it's just an amazing view, the depth of field and, you know, the, the high resolution of the structures and everything you see is just pretty amazing with these new devices. Um, here this is a, this is a paper from Barrow, from the group at Barrow, they actually looked into suturing, um, bypasses under, uh, using a 3D exoscope, a high definition 3D exoscope, and they, they also had, uh, great experiences with it and actually made it work. Um, so the question now is, and the question now is like, how can it be so similar to a microscope, because a lot of people think that microscope is actually a, a real 3D image, it's a stereo optic image, but it is similar to a microscope because the microscope also is not a real 3D image, so the microscope is also a stereoscopic image and, um, that has something to do with, um, with the physics of a microscope. So when we have a, when we have, when we look at, at a three dimensional space with, with our, with our eyes, we see that the line B is closer because it has a different angle than line, than line A and C. So this is called binocular disparity, but that depends on how far our eyes are apart, right? So our eyes are about 6 centimeters apart and that's how we view the world. However, when you look through a microscope, the objective lens is only about 1.3 centimeters apart, right? But because the light is reflected in a binocular system and then it gives us the idea as, as if what we see is actually 6 centimeters apart, but it's not. And that's why it's so difficult to learn operating under a microscope because our brain is not used to it. You think you're looking with your eyes 6 centimeters apart, but the reality is it's only 1.3 centimeters apart. So that's why actually a microscope is not a real 3D image too. Okay? That's why it's, it can be very similar to an exo, 3D exoscopes. Because it's basically also just two image projected for you. Um, so just as a conclusion, I think that we can say that exoscopes provide, you know, definitely more comfort for everybody in the OR. They have a higher field of depth than microscopes and, you know, monocular vision, you can, you can work in a 2D field, but 3D exoscopes are probably going to become more and more prominent. And I think that 4K resolution really allows for great visualization. It's probably going to be the future. Yeah. >>[applause from the audience and inaudible dialogue in the background.]

exoscopes

spine surgery

benefits

ergonomics

depth of field