e-NABLE e-NABLEcon 2019, 14 Oct 2019

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From YouTube: e-NABLEcon 2019 - Chad Coarsey and Marty Cheng - 3D scanning and socket modeling demo

Description

In this video, Chad Coarsey (Director of Operations, The Bionic Glove Project) and Wen-Yu (Marty) Cheng (Undergraduate Researcher, FAU BioRobotics Lab) demonstrate how to take a 3D scan of a limb and create a custom socket using Meshmixer.

More information and discussion about EnableCon 2019 here: https://hub.e-nable.org/s/e-nablecon-2019/

More information about e-NABLE here: https://enablingthefuture.org

A

All right, so you all saw this morning where Mari showed off.

A

They have the feedback system, so I think we're going to take this opportunity to kind of pass around some of the haptics right now and then we're going to get into actually the design flow that we get so with our process that we're using we kind of have to create a tailored solution that fits really formed to the arm because we're doing a myoelectric prosthesis here and so in order to do that, we have to integrate a 3d fragment, scan or 3d scan to get to the printed stage, and so what we decide, we're going to do is show you kind of how we get there and so again, with one he's going to pull his computer and with the sensor in he's.

A

Gonna do a scan and once he does, the scan he's gonna put it into software, which I watched him and he's gonna make me infected. So this will be marvelous life right now.

B

So here we go Connect software. It.

C

B

C

B

Software comes with our scanner. There we go alright, so let's try it. Let's go with body, so 0.6 meters will be how far away it would need to be from the object. But in this case is chance arm and.

B

A

Actually, we want to have someone yeah. Do the scan, there's.

C

Some moments out no.

B

A

Were trying come on down yeah alrighty.

B

There are the instructions, the.

C

B

Box is basically a box around the object you want, so it needs to stay a certain distance away where it's green. Okay, you can see here so if it's too close gonna be ribs too far, it's gonna be blue. Okay,.

C

B

To keep it green yeah, so green green is what you want and if you move it's basically a circle around the object. So when you move go make sure it's about the same distance away. Okay,.

C

B

This is pointing directly perpendicular to.

B

C

Make sure that it's.

B

Pointed perpendicular to it and see.

C

It's Woolfolk AC, so.

B

That this is why we need the rig. So it's.

A

Even when it's when it's too far away, what do we do.

B

But make sure it's it's green, that's all you need. You can resize decrease the size.

B

You want to choose the size of the box I. Don't think that! Oh, let's see! Oh, is that about the same okay, so you guys just ready to start try it.

C

Out sure what is the pixilated, okay, yeah.

B

It's good yeah. This is one figurine is all right. Okay, so mover. Whichever way you want when it starts okay- and you want to be a little slow, not.

C

B

Make sure this is in the center of the screen as well.

A

Yeah, this is where you have to kind of get all on the ground, sometimes and I. Think Jeremy had a great suggestion when you're doing these scans. It's really simple! If you just stick your arm vertically in the air, so you don't have to kind of get on the ground and worry about. You know losing you're, maintaining, go.

B

A

B

Sure it stays in the frame, they give me a quarter.

A

Another limitation is you're only in this enough that you're only bound to the the distance of the court so and the other methodology of scanning can use the iPad stand directly with the program built into the iPad, and it creates a scale image that you can export to.

C

B

D

Right I think we are twenty something about twenty-two.

B

All right here, I think it I think I got everything.

B

C

It might not be too great because.

B

Sometimes that this things around the arm is moving around a little bit. So, let's see what we got.

A

So when we were doing this on the iPad- and you know streaming it into the software in the computer, it would take about five to ten minutes for it to process the image, but with the dog. Oh it just simply, he puts it all together and you can move in to pre-process. So.

B

It's actually really good all.

E

A

That's just missed the tip, but that's you know. That's.

B

Okay, okay, so, as you can see, the tip here is missing and that's okay. We can fix that in post processing as well. So once you have to scan this, you can export this into a steel, but let's take care of this stuff. First, let's go to process. Let's go to moving crop.

B

And crop out all that stuff. You can do this in mesh mixture as well.

A

So while he's putting them I'm going to pass around some of the pieces, we've made from these the scan process. So after we have the flexible material for the outside, it's now printed flat, and then we also have the distal hand, which is printed in nylon, correct, yes, yep! So it's.

B

A special nylon, if you want to know what type it is, is a special nylon called PCT GE from tall men. It is a lot more flexible than normal nylon and still retaining its layer, bonding qualities.

E

A

B

Printed it on a an Ultimaker, both those parts. So now we have now we're trying to export this. We are trying to export into a steel and, let's export this I'm, just gonna put it on the desktop and name it.

B

So now we go into mesh mixture.

A

Whose these metrics are for raise your hands? Okay,.

E

That's right, but it's it's a brand new. Every time.

B

Import is what I meant to do.

B

You can import this file into here and now we're gonna try to fix the problem.

B

I can't oh I can't see it from here.

A

Now one thing we're interested in is how good is the accuracy on these scans, so one idea that we were thinking about doing it, an upcoming clinical study. This actually measure the moles in the cat that we create versus the actual physical measurement very similar to how the FDA was doing simulation, testing and actual testing. You saw on the image that the a pariah this morning, the image of that acetabulum of the hill, where you saw a traceable line of the image, but also the actual line, and it was significant deviation.

E

More, do you need to explain what.

B

I was talking so inter border to fill this hole. Any blue line you see in meshmixer is a boundary line. That means it's open. That means we all know what it meshes right.

F

B

I, guess not sorry, that's what I meant. Does anybody not know what mesh a mesh has is basically a surface zero thickness surface and it could be in triangle triangles? It could be in rectangles. So here we have triangle meshes and the meshes need to be bound together for it to be a full, solid body here this is open. That means this is not a solid body. This is a zero thickness show. Basically, so we need to open. We need to close this in measure.

B

Make sure if you see a boundary, you can double click near the boundary and it will select that boundary by itself. You can expend a little bit by controlling and scrolling on the wheel. There is an option called joint, just kidding, Oh.

B

B

B

So this I guess this is where masters fear sometimes has problems. He's got a troubleshoot a lot of it. Let me try and troubleshoot you, so you know where to close this, there's a lot of tools in meshmixer right now, I'm using the sculpt tool.

G

B

Setting it to robust smooth so there's Barry, there's a lot options here. Are the brushes there's drag, there's a drag which you can drag the meshes around. You can pull outwards and pull it wherever you want, there's a draw which just expands it out in the direction that you want, and these two are very similar, but probably don't have time to go over that much. But if.

E

I make people who you never I, never get used to measurement. The menu structure is quite puzzling it, but you can do almost anything with it and so watching what.

A

He and what dr. YouTube is your YouTube I learned.

E

Everything from you difficult, this veteran video will be on YouTube, so so you're, basically.

D

E

Moving it up so the.

B

Mesh picture is very finicky, and sometimes it just doesn't like certain shapes, and it won't do things that you want it to do so. Let me see I'm trying to smooth that that boundary, so it and see if it can. Let me see.

A

What are your purpose you're, just creating a socket of the upper arm, so in you know, quesa negligible as far as the Intolerable finish the model, but if you were considering doing something for that distal anatomy, that's missing! You may want to consider rescanning or even trying to get a more robust skin.

B

G

B

Trying to trouble she so I guess if it doesn't close, we can always making it to the solid. Let.

F

Me see how it goes. Yes,.

A

You have good practice and you are an artist, go by all means, go for it, but that is very.

D

A

The simplicity of it yeah.

B

Here's the hole right and right now, it's a surface that there's no thickness and I just used to make solid tool. He'll try to fill the holes and connect everything together to make it a solid body. So that means this holes filled and this holes filled and now there's.

C

B

Actually nothing in there, but it's a solid found buddy, so there's no way to get inside it's. Basically. It's.

B

Yes, you do which.

A

We do print out the models yeah so.

B

Right now, the the reason we're trying to fill this is because we need to make a socket and we're trying to offset from us from this scan and, if there's a hole that it's gonna be problem.

B

So now that it's a solid body we can. This is where your artistic skills come in. You can literally just draw whatever you want. This is how I design that particular shape I can draw like this, and I can offset this from the socket. So this is very customized to Chad's particular arm. So you just want a socket. You can't inverse elect it.

B

So this I don't know I'm not exactly too sure how this works. So it's inversely selected. Let me see yeah.

E

B

Is no joke, so let me go to nothing select. Yes, there is a there's. You can just click outside of the scan drag it across and it will select one of the sites. I, never know which side, oh geez. So if this likes the wrong side just go to modify.

G

B

Click invert, it's basically like Photoshop. So now it's inverted now it's the as the selection that we want whenever and the goal is offset this right. If we click offset, it will offset the surface away from the skin and I. Have it at zero right now, let's say 2.5, which is a good number that I usually use it. So.

A

That's the distance from the actual body you want to offset.

B

Because you don't want to just have a simple crank on top of your skin, you want padding you want. You want to accommodate for that, no matter what how thick it is. I feel like 2.5 millimeters is pretty good.

F

So this offset you're, basically defining the lower surface, the surfaces closest to his arm and then I guess. The next step would be this. This mm-hmm.

B

So the the process are the process of doing this whole thing, because there's a lot of things that we need to do before we can do all these steps. The steps are get the scan fix. The scan offset this one, this single surface away from the scan, so we have one surface, offset it again to the thickness that you wanted to could and then there's an option when you offset to connect the two surfaces, so it become an actual thickness and then, when it's connected, do you have technically the socket, but it friendly solution.

A

B

To not for the padding yeah.

D

B

Feel, like that's pretty.

A

Good for any it, it depends on also what grade of padding they're using that's where the user intuitiveness comes in, so for myself, I like having moleskin at the distal tip. So it allows me to have less of that pushing on my appendage, but I have the comfort on the upper arm, where it's kind of bearing a lot more of the weight as it's being distributed up. My arm so I feel like it's a lot more couples having more than one modality of foam. In that case,.

B

So whenever this happens, what I like to do.

B

So it's it's solving, it's not solving, so what does it mean by solving? What's it trying to do right, it's trying to calculate the offset and trying to render an offset, but it looks fairly, not so I'm gonna force quit that.

G

It didn't crash it.

B

But I know it's not gonna go anywhere, so we're gonna, restart whatever. Whenever this happens, okay do not reopen the file close. The program, click that open mesh make sure but don't open the file, and it will prompt you with mesh brings reversing the class. Would you like to restore yes.

A

B

And I'll give you back your file if it's not safe, don't worry because it's automatically safe. So let's try that again.

A

So you're gonna create the boundary you're gonna invert it and now it's got the full arm.

D

So you basically you're slicing, it didn't even pick whichever slash let.

B

Me see if it works now.

G

B

No, that shouldn't be a problem.

F

B

We we selected a surface, so it's trying to often that selected orange part away.

D

So it's trying to draw the part you selected and paste it on it's now trying to replicate that two and a half milliliters Lord. Yes,.

B

D

A

What we do when it's you know fully. That's sorry. It's.

B

Going it's going to do.

A

The initial offset to create that gap, but then you can offset it and tell it to join that offset with the previous one. So that's where you can create the thickness of whatever socket you're, putting on I.

F

B

If I should just open up my hole, I'm working.

C

B

That's find out close MATLAB.

F

B

Here's the thing about SolidWorks, it's very good, Oh crash. That's why SolidWorks is very good at creating geometric shapes, like gears, cubes, anything like that, but with an arm, it's very organic and it's very different with everybody. So it's gonna be very hard. There.

A

Are some good videos, Ben Ryan Paul, so P Autodesk they've established great videos workflows from creating OBG OPG? Sorry obj.

C

A

We go obj file and, what's converting it to from a triangular mesh to a quat much so the quad man should get 90 degree angles and lines that are parallel to one another. And then you do these T splines, where you pull it over and you're, actually creating the object inside work as a solid piece. So that's how you would go from this into SolidWorks.

F

B

This isn't exactly surfaces is more mesh for services. It's a little different, the surfaces in SolidWorks for you to make it a shape like this, you have to use a bunch of splines, you have to do a bunch of 3d sketches and I've tried it, and you know what let me. Let me let me redo this. Let me just do opposite. Basically, a offset of your risk portion how's that I did sorry I'm working in the background, I'm 42 I'm a.

D

B

But I've done it left bunch of clients I'm doing a bunch of times. I should be okay, let's like this part, this time almost like the other part, let's like this part this time, what I want to show you is.

B

I guess this: this doesn't like me whenever I.

B

So, yes, if you, if you have a computer with better graphics card at that point, you didn't use it and.

A

That's good for any CAD software in general,.

B

I think 16 might be eight.

A

F

A

Say so you can play with some of these tools to make it less or more resolute or accurate to the image. So I know.

D

B

Can't close everything then.

D

Well, weren't you! No! You, professor I.

F

B

Need one is that a project that was ditched all.

C

B

You know I'm gonna use the old one. Oh then that's fine just built from you, so this will be a different scan, but it's basically the same things. They want.

A

Same arm different scale.

G

A

When you, when you have the STL file, if you can get away with a lower size, it definitely won't place.

B

That so the resolution means there. Is you can't you couldn't see it, but there's a lot of tiny, tiny triangles on there. Lower resolution means it's gonna, be bigger, triangles and less lesser. What's less.

A

B

Sorry less triangles and bigger triangles okay, so this is the file from which I made that socket.

B

I'm gonna hide all this stuff, so we can see the original skin so.

A

What's that right, there you have this.

B

Is the object browser? This is very, very important. You can select different things that you've made, so if I can get it I can't see from here from here, you can get. You can open the object browser by going to view and clicking show I showed object, browser this says hide cuz I. Have it yes,.

A

When you're working with very complex models, lots of work into it, it's good having this object browser, so you can kind of go to each of those workflows again back to that process control the.

E

Object browser is actually showing the stages in the evolution of the object. On this brief.

B

So uh so the fights is pick up this. These are different objects that I've created before and I just haven't had time to delete them. This is one of the prototypes. This is one of the other prototypes, so.

A

Yes, that is like a way of doing our process control your having each of the iterations in this browser.

B

Here's the thing about meshmixer it once you do something it won't once you do something they won't. Let you undo it as in once you save it. You can't undo it so you have to save a bunch of different iterations. As I'm saying once you say you modify the you modify its Alex Allah works.

E

B

Can't you have to save as a separate file, so he can go back to this file. It's editing it there's no.

E

History feature alright.

B

There's no history, like SolidWorks therapy, I get a separate.

A

Things he's documenting it kind of shows his progress for his own intuitive purpose, but yeah there's no track ability enough. Alright,.

B

We only got a few minutes. Let me see where is that good one.

B

Let's go with this: oh that's not.

B

Okay, let's say it off set it correctly. This will be the correct offset right this purple. Shell is the opposite. Let's say it did it correctly opposite now you need to offset it again, select all which would be control a or double click on the purple surface. Then you need to offset again to create that thickness, but I don't know how? Oh it didn't really well, this time.

E

It happens, yes,.

B

E

B

Will see sometimes you'll see these weird jagged edges right, these weird jagged edges: they are there. There are spaces to fix them. So for this second offset, you want to make sure that you click connected now connect these two surfaces together when you offset so you click upset, except now you have a closed surface now you clear selection, so it's not select anymore. You have this socket here now you can hide. Your original scan should not see you anymore. Now you have this the socket.

B

Now there is a lot of different options of fixing and making a look but I'm, slowly, I'm selecting this this surface right here any difference in color. You see you can double click to select it. So if you want say you want to select just this edge right here, this green edge, you don't have to go around and select it. You can just double click on it.

B

You can double click mash, make sure it doesn't like me. Double click and I'll select this green section, press, ctrl and scroll on your wheel, and it will expand that selection a little bit and let's say we want to smooth it out. So there's no jagged edges, you can go to this form, go to smooth and it'll, smooth it out and you'll, see, there's still a little bit. That's ok! So.

A

You can change with the smoothing tool, change.

D

Smoothing scale but but.

B

The higher you go, the less they'll take away or the more I'll take away for some for some, which are the things.

B

So, let's say even with that, there's still things here and go your sculpt tool and there's a lot of brushes here, there's mobile smooth, which means if it's something that is like just look at the picture here, something that is a little further down. You can smooth it. So it's bubbles out and that's something that's pretty out. You can bubble, though you can smooth it, so it stays flat and there's a request which just combined sort of both so we're gonna use this the shrink smooth and.

A

Why are you doing that, while we're running a lot of time? Does anyone have any questions right now, Molly.

G

A

I think you've been on this one. We have a marker where the next prototype will actually eliminate some the material to allow for the better baby years.

A

What's the specific specific software she was running or is it just hello.

B

Me I'm writing on time, but let me show you something really fast. That is probably really important for us to be, but.

B

In order to make something that that say, you want to attach one of your hands on to the socket all right you can do. Let me just finish this real go ahead. I know I'm running out of time.

B

One five how's that there.

B

It's foreign to.

A

Us so you can rotate it on three different axis: YZ yeah.

B

It's just oh, that is the wrong hand, but that's okay! Hey there done that.

G

B

But I don't have time for that. So if you see there's the blue, there's the blue boundary right, we're trying to connect, let's say we're trying to connect these two things. We need one boundary and another boundary to connect those two. So in order to create a boundary on this side here we need to select when you select a relatively same sized hole.

B

And then we're gonna delete it, so it will create a boundary for it to not look weird, we need to smooth that boundary out just a little bit delete this see how there's a boundary now so now, right now, these are two separate entities there. You have two separate objects. We need to combine them into one object right now: click combined. So what is? It was I clicked. This shift click this. It gave me that option to combine those two. Now it's in one single object right.

B

So if I click out of this, it doesn't see this anymore I click into this seat. Both of this now I need to combine those two boundaries, double click on this boundary and this boundary and then I can join. This will join the two that.

C

A

Look too great, but.

A

B

Not no is it on the wrong hand, but it's sort of weird. So yes, this.

D

B

This is how you can build this I can build your own socket and your own hand, and you can print this with flexible material and with time and care you can create something like just like this. There you go and you can create this anything you want to attach. You can create an Saltworks import it as STL, and then this you can connect everything together.

A

Questions will be in the back and you can ask there. Thank you very much.