A solution to cold feet in ski boots? VPECS technology

Hello and welcome to another episode of the Big Picture Skiing podcast. On today's show, you're about to meet Henrik Björsten, a cardiac surgeon and inventor of something he calls the VPEX system. I'll let him explain in the podcast, but really it's all about making your feet warmer inside of your ski boots. So it started with a his daughter asking him the question, "Dad, why do these thick, well-insulated ski boots still end up giving me cold feet?" And that question sparked something in Henrik he wanted to solve, and I think it's an absolutely brilliant idea. I really hope it comes to fruition and ski boot manufacturers out there take on the system and install it in the boots, 'cause I want it in my ski boots. Because not only is it gonna make my feet and the circulatory system be able to get blood to my toes more easily, I'm gonna be able to buckle up my boots in a firmer way so the performance for enough balance I'm gonna be able to get when my ski boots are done up is going to be far greater than without the system. I really hope you enjoy this episode with Henrik, and let's jump in and listen to his story and his really interesting invention.

Henrik, thank you very much for joining me today. Now, for all the people listening, what is VPECS? What have you designed and come up with to make ski boots more comfortable?

First of all, thank you for having me here on your podcast. VPECS is an acronym that stands for Versatile Perfusion Control System. Perfusion is a term that I use in my profession for blood flow. We need to have blood that flows all over the body, and then we would use the term perfuse, that we perfuse the organs. And what I have done is an adaptation of a ski boot liner that respects the anatomy of the middle foot in a way that it actually preserves blood flow all the way down to the forefoot in a way that no boot does today. And also protects important nerves. Moreover, it has one feature that is quite interesting, that it can— it provides a better grip of the middle foot in the ski boot. That is a short explanation of what WEPEX stands for.

Yeah, when I saw this— and we'll go into a little bit further, uh, in the chat here— but when I first saw this, it really piqued my curiosity because, uh, I— you probably don't know yet, but I'm very interested in the body and particularly the feet. The feet are one of my most favorite sort of parts to understand and, and look at and, and do movement exercises with. And so when you came up with this, I was like, oh, that's quite brilliant. Now, how did the idea come about? Like, why did you think there was a problem that needed solving here?

Yeah, it's quite simple and sort of obvious when you look in hindsight. 4 years ago, I went skiing in a small Swedish ski resort with my 7-year-old daughter, and they sort of asked, why are your feet cold when when you have such thick boots? And that's a very good question because ski boots are thick, they are well insulated. You don't have direct contact with something that's cold. You only have contact with air. So you should not be freezing in your ski boots. And of course, everybody has realized that you still freeze in the ski boots. And then I started to sort of adding that question with my knowledge with perfusion or blood flow in the body and the arterial anatomy or the anatomy of the arteries in the foot. And could there be something there? And I am a thinker, so I sort of— yeah, these sticks in my head until I have sorted them out. And I soon come to realize, yeah, maybe there is something, because the most important artery that provides blood to the toes actually runs on top of the middle foot. That is where we took off of testing this hypothesis first, and then afterwards trying to do something, making prototypes and developing the VPEX system. So it started with a very easy small question from a young girl, and then I had developed into a new system.

And so developing this, like, what were the, what were the stages you, you kind of went through? Because I'm sort of interested in, like, you know, if you go and you try and approach a problem like this, like, yeah, what, what were the steps? Like, did, uh, yeah, how did you first test like maybe some of the, the tests you did to see how much that affected blood flow to the toes?

Yeah, that is, being a scientist as I am, I had to sort of measure the effect that we have here. And we looked in, how could we do those? So what I did first was actually to take one of my old ski boots and then just take a saw, a tiger saw, and cut off the front part. So I had the toes loose, and then we could start measuring. And we used laser Doppler technology to make micro blood flow in the skin. And then we also tested toe pressurement where we actually measure the toe blood pressure in the toes. That can be done. And then we did it with the ski boots. And then I sort of buckled the ski boot and saw that the blood flow reduction could be up to 90% in the toes when buckling these—

Wow.

Ski boots.

90%.

Up to 90%.

And so what's the kind of temperature difference someone might actually experience between that, you know, that cutoff versus full free flow?

Yeah, that, that, that's a significant difference. And we have done some initial testing in modified ski boots and come up to between 4 and 5 degrees in temperature difference between— I tested on my own feet one boat, the left foot having the system and the right foot not having the system, and then temperature probes in between the toes. And then you can see that there was a marked difference, and that just continued to grow out through the testing phase. So, we had to stop for different reasons after 3 hours, but it just started to continue to grow, the difference between it. So, I think in some circumstances the difference might be even bigger. Wow.

Okay. Like, I mean, in Celsius, what sort of degree difference are we talking about?

Yeah, we're talking 4 to 5 degrees Celsius, and these were all good conditions and that. And of course, for the next ski season, I want to test it more, more and more and see if we can get more robust measurements. The problem is good measurements in the foot while you're skiing and being still comfortable having temperature probes in, in your boots.

Yes. Now, you know, something interesting, I think, you know, there's different, uh, bits of advice out there, but a lot of the, the advice from Bootfitter would be to not really buckle down the buckles that are over, like the first and the second buckle that's over the top of the forefoot and the instep. And so part of that, I think, is because the— there's a problem that's created that you're trying to solve Um, do you want to explain a little bit about the anatomy of the midfoot and what a conventional ski boot tongue and overlap system— the design there— how that interferes and affects the foot?

Yeah, that is an interesting question because once I started to get interested in this, I have looked through different CT scans, MRI, and also depictions of the foot in different angles and transections. And when you look at the midfoot it's actually triangular in shape, more or less. Almost not a perfect triangle, but meaning on the ridge here, on the top of the midfoot is where the artery and the nerve runs. That is important for your blood flow and pain. And I've got the—

for people that are watching this, yeah, you can actually see it. So this is the midfoot here of the right foot.

I'll go back.

But yeah, it's that section where the green turns into white you're talking about, isn't it? That's where it's triangular in shape.

Yeah, if you put it even the transection a bit higher, then you have the green here, it's even more triangular. And the ski boot, that has a round conformation, and when you buckle, the forces will tend to make the triangle more and more round, meaning that you get one extreme pressure point, just as you can see on the nerves on the top there. It's like— I will measure also one way of measuring this is to do pressure mapping on the dorsal aspect or on the top of the foot. And you can see where it's showing here that you get one distinct pressure point there because the ski boot and the second buckle just pushes this down toward the sole. And then of course you get the occlusion of the artery and also the pressure on the nerve. So yes. Perfectly sort of— the ski boot does not respect the middle foot. It's very good for many things, but there is one soft spot or one weak spot, I would say, in the ski boot design versus that of the middle foot.

Now I've put all the full sort of arteries and nerves on here. You can really see that section there. You compress that down, then this whole front section is affected. I'm just going to share your your site. So that pressure part I think is important. So what is this diagram here on your website showing?

This is one way we wanted to go forward with this when we looked at what happened on a ski boot and when we did our VPEX modification and how it worked and how we should design it was to do a finite element analysis of this, or finite element finite element modulation just to see the forces and how are they and how will they be distributed with them without the system to get a better understanding for how it works. And yes, that confirmed my feeling of how we should design a system like this, but I still wanted to go ahead to have sort of some hard data on the design before we did the, the final design of the system. Looking now, it's sort of very basic. This is the archway which we actually have made reconstructed from a CT image of a foot. And then you can see that you have the, the sole or the instep of the ski boot where we have created a channel. And above that, we have also the dorsal protection plate that will help to distribute the forces not from the top but from the sides. Yes.

Okay. And because if you look at a typical sort of, uh, liner tongue section that goes over the foot, it is, it is definitely not shaped in the, the fashion you've got here. It's kind of flatter, isn't it?

It is. And then, as I said, because the peak or the apex of the middle foot just stands up like a ridge in the middle, and then you have the pressure of the second buckle coming from above, so you need to create that space for the ridge of the middle foot so it can be free and yes, rocker is running freely.

And so this little chart here showing unbuckled and then buckled obviously, and then with VPEX buckled, like there's not much difference really.

No.

And what is that percentage showing? Is that blood flow?

That is the baseline blood flow that we have. We started with blood flow before buckling and then we buckled and and then we see with and without the VPEX system. And that was quite fascinating. First, we saw that there was a huge reduction in blood flow when we are back to traditional ski boots. And yeah, of course, that is what we expected. But then we did the VPEX adaptation and could see that we are completely preserved. And that made me a bit— I would say I didn't expect to see that good an effect of it.

Okay, wow. Yeah, okay. And so is this kind of the, the working prototype at the moment where it's a full kind of replaceable tongue basically? Yes, you would insert. Yes. Okay, is that carbon fiber down there?

That is carbon fiber. You can either do it in carbon fiber, you can do it in stainless steel, but you need something that can resist the buckling and unbuckling throughout the thousands of cycles.

All right, okay.

I had plastic that would still yield after a few bucklings, and then the system, the effect of the system would disappear. But you need something, yeah, durable, because there are high forces when you buckle. Yeah, the second one.

And I think I was, I was asking you too about, uh, not only the, like, the blood flow and the, like, those positive effects of warmer toes, that sort of stuff, What about, um, performance? And I know maybe you haven't actually measured it as such, but have you yourself found any difference in the ability to feel like better control of the skis because you can now get a better buckling of the, of the midfoot down?

That is a very good question, because when we started doing pressure mapping, we put pressure sensors on top of the middle foot. We could see without the system there is one pressure point that pressures exactly on top of the middle foot. And does so very hard. But with the system, that pressure point is moved into two pressure points on the sides. And then I realized all of a sudden we have a three-point fixation on the middle foot instead of a two-point fixation with just a pressure pressing down, working more or less against the arch of the foot, trying to press, press that down. Now we get two pressure points from the side, and that should secure the middle foot better in the ski boot, which would in lead to better force transmission for sort of more, more alpine races that have high demands. So I think that's another feature, and that's quite interesting. Once you start digging in this system and thinking about it and measuring things, you do see new things also. So I think that is a feature that comes as an extra with the, with the VPEX.

This episode is brought to you by Carv, the digital ski coach. Now, one of the features I've had the most fun with all time is simply the fact that Carv tracks every single single turn you make. I treat it a bit like Strava, so at the end of the day it tells me exactly how many turns I've done, and those numbers keep adding up across the season. So last season in Australia, I had a few days where I was doing nearly 2,500 turns, and my legs were tired, but it was really cool to try and have that number there motivating me. And I'm quietly working my way towards my 1 millionth turn with Carv. So the other metrics I've been diving into lately, and these are new for this season, are very unique and these are turn corridor and turn radius, and I don't see many skiers using them, but they tell you a lot about the shape and flow of your skiing. So the turn corridor shows you how far you're traveling across the hill, or the time almost between apex to apex, and how long you're taking to transition, while the turn radius measures the actual arc you create once you start the turn. So these can be different, you can have like a very wide corridor, say 18 meters, but a lower turn radius, or the other way around. So when you compare the two, it opens up a whole world of experimentation, and it would be a bit like a race coach will set different types of race courses to influence a racer or skier to change the timing and mix it up. So I encourage you to look into this if you've got Carv and play with it and see if you can manipulate it, because it's only going to improve your versatility. So I keep my Carv on my boots every single day because you never know quite know when, like, a change in technique or a new ski resort or skis will show up in the numbers. and it's great at the end of the day being able to check that, or even after the fact. And I'm really looking forward to the day I open the app and I see turn number 1 million. So if you want to explore your skiing in a completely different way, check out Carv, the digital ski coach. And thank you, team, for sponsoring this episode.

And I know you're, you're the scientist, so you, you don't like claiming sort of anecdotal stuff, but did you feel, did you feel a difference? Like, do you feel you ski with better grip.

Of course, you start to ski and then you feel, yeah, you can feel the difference. But honestly, if I hadn't been thinking about it, I might not have felt the difference when I skied.

Okay.

It's very subjective, and I don't like being subjective. I like being objective like this. I want hard data to show this is the fact, this is how it works.

Yes. Yeah. Okay, fantastic, fantastic. And were there any kind of, uh, ups or downs, like challenges along the way that were like sort of interesting to, to overcome? Like, what was the first way you tried to distribute this pressure so it wasn't all on one point, it was over, over two points? Like, how did you come about— yeah, was there a first type prototype that wasn't, yeah, as effective?

Yeah, what the thing is, I've gone through destroying quite a few ski boots now. As I said, the first pair I just sawed off the top of the ski boot to have access to the toes, and now I have adapted liners where we created this channel and I put on the protection plate on the upper side there. And that took a couple of rounds before I got it right because it's hard to work within, inside of the liner. But overall, the development has gone without any drawbacks. There has been some works on creating the prototypes that I wanted to just recreate that and how we should manufacture those. But in the overall, minor setbacks as always, but the road has gone ahead quite nicely now.

And where are you at now? What's, uh, what's the, what's the next steps? Because I think we were chatting the other day, like, do you— yeah, how do you, how do you take this into the, into the ski world?

Maybe that is where I start getting the setbacks. What I have done is, of course, to protect this with patents. So we have received a Canadian patent, we have received Chinese patent, we have also received the US patent just a week ago, and the European patent is sort of on the last lap before being finally approved. And the PCT application looked very good, so I don't foresee any problems that we should have good protection with this system in terms of patents. And then it starts to convince people skiboot manufacturer that this is something that they could put into their skiboots and actually sell with a premium price. So what I'm doing right now is trying to get market research data to see what people, skiers, bootfitters, think about this system. Is it good? What do they think? Can, you know, their companies, the skiboot manufacturers— so the big question is, can they make money out of the system? And I do honestly think so. There is a premium price because everybody freezes. And you know that people tend to buy these active heating pads or socks for ski boots that are quite—

That's me.

You have one of those?

Yeah, yeah, yeah. It's not cheap. So if it was, yeah, included in the price of the boot, it would be better. And then you're not having batteries attached to your feet and they won't break down either.

So of course there's a premium price, and that is important to show that they can make some more money doing this system. The good thing is that the adaptation and the cost of materials is quite low with the system. So I hope so. So I'm getting the market data, I have the patents in place, I have started to set up a website. You showed some parts of it for anybody who's interested. And then I have gotten contacts in industry and start making talk, start discuss with them seriously about incorporating this in ski boot. So hopefully it will be on the shelf of the ski boot uh, selling in different shops.

Yeah, I, I look forward to it. I mean, yeah, that's why I reached out to you. I think it's a, it's a brilliant design. I've had frostbitten toes, so now I have to, if it's a little bit cold, use heated socks, that sort of thing. And then I, I really could see the performance effects. And you know, not everyone's out there to ski incredibly well, but I really enjoy that part, so I could see it it sort of have a, have a twofold effect in, in, in a positive way on, on both those areas. So I'm, I'm quite excited. Hopefully some people that are listening here that are connected in the ski world, that know the boot manufacturers, that sort of thing, get it, get a hold of this, because I think it would be fantastic to see it incorporated in general, uh, in ski boots around the world. Henrik, is there anything else you wanted to, to add here or, or, um, direct people to in case they anybody did want to get in touch, maybe say the, the, the website.

Yeah, the website was set up a month ago, and you— everybody's of course welcome to look at that, vpextechnology.com. So it's VPECS, Versatile Perfusion Control System, and there you have contact information on the website if you're interested in contacting me.

Great, fantastic.

Well, yes.

All the best with it, Henrik. I hope it goes really well. I hope to be skiing with it in my boots someday, and I'm really grateful for your time chatting with us today.

Yes, and thank you for having me. It's been quite an honor to be here, and I hope that you'll see this Vepik ski boot soon.

This episode is brought to you by Carv, the digital ski coach. Now, one of the features I've had the most fun with all time is simply the fact that Carv tracks every single turn you make. I treat it a bit like Strava. So at the end of the day, it tells me exactly how many turns I've done, and those numbers keep adding up across the season. So last season in Australia, I had a few days where I was doing nearly 2,500 turns, and my legs were tired, but it was really cool to try and have that number there motivating me. And I'm quietly working my way towards my 1 millionth turn with Carv. So the other metrics I've been diving into lately, and these are new for this season, are very unique and these are turn corridor and turn radius, and I don't see many skiers using them, but they tell you a lot about the shape and flow of your skiing. So the turn corridor shows you how far you're traveling across the hill, or the time almost between apex to apex, and how long you're taking to transition, while the turn radius measures the actual arc you create once you start the turn. So these can be different. You can have like a very wide corridor, say 18 meters, but a lower turn radius, or the other way around. So when you compare the two, it opens up a whole world of experimentation, and it would be a bit like a race coach will set different types of race courses to influence a racer or skier to change the timing and mix it up. So I encourage you to look into this if you've got Carv and play with it and see if you can manipulate it, because it's only going to improve your versatility. So I keep my Carv on my boots every single day because you never know quite know when like a change in technique or a new ski resort or skis will show up in the numbers. And it's great at the end of the day being able to check that, or even after the fact. And I'm really looking forward to the day I open the app and I see turn number 1 million. So if you want to explore your skiing in a completely different way, check out Carv, the digital ski coach. And thank you team for sponsoring this episode.