How to Implement the Top Trends in Biomechanical Testing

How to Implement the Top Trends in Biomechanical Testing

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Welcome to our webinar, on biomechanical. Testing trend i'm carolyn, lowell with bonezone. And i appreciate, you joining us for our discussion, about biomechanical. Testing, trends. As engineers. You understand, that biomechanics. Important role in developing. Innovative, implants. And of course testing, technology, plays. A pivotal, role in ensuring, that your, product, functions, as it was meant to. Today we have a really great presentation. On how to incorporate. 3d digital, image correlation. And ct, scanning, into your testing. And through research. Imagery, and videos, and in-depth, orthopedic. Examples. You're, going to gain knowledge. About how this technology, works, and its specific, applications. Before we get started, i want to thank our sponsor, of today's, webinar, trillion, quality, systems, for. Sharing their expertise, with us. Trillian, offers digital, image correlation. Systems, in consulting. Services, for numerous, fields, across north america. For orthopedic, engineers. Trillion, systems, can assist with. Micro motion measurements, between bones and implants. Joint dynamics, and motion capture. Strain, quantification. Tendon repair, studies. Those are just to name a few. And you'll get to see some of those applications. In action today. Our trillian expert today. Is. Justin buchenski. He is technical, account manager, at trillian's, great lakes regional office. Justin, graduated. From ferris state university, in 2007. He has been working, in the automotive, related, technology. Field for seven years. And uses, his, previous, experience. In the field of, secondary, education. To build relationships. In higher education. Research, development. And manufacturing. Industries. Also joining us today, is elise, martin, who is a biomechanics. Engineer, at ubmd. Orthopedics. And sports medicine. Dr martin received her biomedical. Engineering, doctorate, from suny, university, at buffalo. She has been working to develop, various research, research, and analysis, techniques, to, better understand, and improve various, orthopedic.

Implants. And she has a focus on reverse, and anatomic. Total shoulder arthroplasty. And you will you will get to see some of her research, during today's presentation. We appreciate, justin, and elise joining us today. You, our audience, have opportunities. To ask them questions. We will pause for a q a q a about halfway, through the presentation. And then we will, offer another q a at the end. You can use the q a function, at the bottom of your screen to submit a question. Justin. I am going to hand it over to you to start your presentation. Uh hello and welcome, and thank you so much for that nice introduction. I do appreciate, that. Um. I'm, excited to be here today to discuss a promising, next chapter in the field of biomechanics. Research. I'll be showcasing, some real life applications, developed by our team drawing from experience, our own experience, and discuss some current examples. Of how this technology, can be applied across the industry. So uh let's go ahead and get started. Work for trillion an american engineering, firm it's been in business for the last 20 years, i specialize, in the development, of optical, 3d, measurement and analysis, tools. We help our customers. With application, development, and consulting, services. And turnkey, system deployment. We're growing business with our headquarters, in philadelphia. And offices, throughout the us you can see here. Each office keeps his systems on hand and supports businesses, locally. Visiting for service work and for training. We're an exclusive, north american testing, distributor, for gom, a zeiss company as you can see at the logo at the very top there. And gome develops the software, in the industrial, systems. And trillium supports, its customers. And their work. Locally. Here's the gome lineup of measuring systems, you can see here, today we're going to concentrate, on the aramis. And the zeiss gome ct, scanner. So, let's get started. Let's uh first discuss aramis. It's an optical, strain gauge for full field strain and displacement, measurements. It's a pair of cameras, and a blue light up above. Aramis, uses triangulation. Between the cameras, to track either target dots, or speckle pattern along the surface of your specimen. We use target dots lightweight, stickers, so you can see here. Anywhere you stick a dot, would be a 3d coordinate. And the cameras, will capture, displacements. In all directions. Along with velocity, and acceleration. In all directions. In the example we see here there's a narrow prosthesis. A blade for the prosthesis, there, and our objective, is to determine, the stiffness, of that blade. In order to isolate the movement of the blade, we place target dots, on the knee as a reference. So although the whole body is moving, our measurement. Is a relative, displacement, of the blade, to the knee. And so. In this way. We can. Use a rigid body motion compensation. Which basically means that, you can bump the cameras and still get a good data set. Alternatively. We can use speckle pattern. On surfaces, to create thousands of tiny dots, accordingly, we get thousands. Of. Optical strain gauges, totally non-contact. These gauges don't care about material, or temperature. This is just off the shelf standard aerosol, paint black and white. The software, automatically, identify, and track the high contrast. Of the pattern, or the target dot. So with strain field like this at this resolution. You can, truly understand your specimen, under load. So this this is the the nuts and bolts of what we'll be doing with aramis. It's not hard to see aramis's. Advantages. Biomedical. Testing. Mechanical, testing. Some of the materials are very hard to predict. And they have especially, complex, geometries. Strain gauges are sometimes, too large for biological. Tissues. Extensometers. Have sometimes. Induced, micro damage to the biological, specimen. So, there's a lot of, reasons why you would think about using us. The aramis, collects values, all along the surface the whole entire surface that you can see. So it's collecting, thousands of locations. In a non-contact. Fashion so you get. You know no user variability. In the, in the data example you see on your screen here.

We Can inspect string gradients, and concentrations. And pull out automatically, the minimums, and maximums. Of both principle, and directional, strains. This is already, accepted, by many materials, labs, and certified, as a class a extensometer. Following astm. Standards. Aramis has a huge potential, in testing of soft tissues, implant testing, for fea. And because of its aroma sensitivity. Micro motion analysis, projects you're going to see some of that today. So we're not contact. So. I mentioned before. No user variability, so this makes us more accurate far more accurate, than, say for instance a foil strain gauge. We give full field, measurement. So you gain, a holistic, insight and anything. Think of something that's inhomogeneous. Or anisotropic. We're going to work great for that. Also, if you have uh. You need to identify, a crack, for crack initiation, or tracking a crack propagation, that's fantastic, for that. We also collect strain and displacement, at the same time as i was showing the previous screen. We're very flexible. So that uh, just change your lenses and you can change your field of view. We're material, independent. So from implants, to bones to tissues we work great. And we measure from static that before and after style photos. Deformation. Static deformation. To high cycle fatigue that can last days, to hammer strikes, that, can last seconds. We, we can actually measure vibration. And we've been used in the past to monitor. The structural, integrity, of bone. After fracture healing say for instance. And we are critical for fda validation, so aramis, brings simulation. Closer, ever closer, to reality. Than ever before with just a single, iteration. Of, our uh, our acquisition. So um, that's a nice introduction to aramis, let's get into some. Aramis, biomechanical. Applications, before we introduce the ct, and kind of put it all together. So this is the rundown of what we're going to be covering, so let's jump into some tendon studies. We do a lot of different uh types of studies. Especially, analyzing, gait analysis. We work with a lot of shoe companies, and sportswear, customers. We're often analyzing. Bodies, movements, during activities. But this first application, involves, a little bit deeper of a look. And so here we have, an in, vitro, study, of the biomechanical. Behavior, of a human cadaver, achilles, tendon. And. Maybe you've heard this before. Out on the basketball, court, but it actually makes a popping, noise as it breaks. Taking a failure here of course. It's very painful to watch. But if you pay careful attention, this is a strain measurement. Not to the concentration, of strain at the very top which is really prevalent you can see that straining. But if you look, down below, there's a quick propagation, of strain towards the bottom, just before rupture. And so, this is a really nice example. Of. The type of. Information, you get when you can shoot it. When you can acquire holistically. And really understand your, material. Another cadaver. Tendon that we have here. This is a time repair model. This is under cyclic, load. And the purpose of this test was to compare, biomedical. Properties, of tendon repairs. So we've divided, between left and right, and these are two different types of tendon repairs, that are being compared. And so. From this measurement we're able to arrive at yield strength. Gap formation, and failure. Comparing, the types of tendon repairs. Uh, between the two and you can see uh, on the on the right side we've got a nice diagram. Showcasing, those points as they're plotted down on the left each time we plot a point. It becomes. Essentially. An optical, strain gauge. And ultimately, this testing. Was uh useful in identifying, and validating. Lower rupture rates for certain tendon repairs. Again, this holistic, style of testing. Gives you so much more data all at once. So that's a pretty nice uh, looking, test a couple of tests there we've seen. Let's move on now, into implant testing. There's been quite an evolution, in hip replacement, research. And aramis, has played a a, large factor in that. And so you can see our speckle pattern on this hip here. And we're used really heavily in the validation, of numerical, simulation. We've been used for that direct comparison, of the calculated, strain fields of the finite element. To the implant. So both johns hopkins, university, applied to physics, laboratory, in mayo clinic, use aramis, and they find their finite element models. Of implant bone constructs.

Should Be evaluated. For their validity, against mechanical, tests. Wherever, it is possible. And with, experimental, equivalence. Obtained, using aramis, like this human femur on the left you can get these uh, great looking compressive, loads and, and run all kinds of studies. So this is a compression. Gradient, of strain. Inspecting, the implants deformation. Under load. Here we see the comparison, of the fea. On the top right. With the real mechanical, behavior, obtained with aramis, on the bottom right. In the past we've also been used as an evaluation. Tool, for biomechanical. Behavior comparative, studies, of dissimilar, hip design similar to the. Comparison of the, tendon repair we've also done some, hip design, studies as well, so. When you're shooting in these holistic, fashions. You can align, easily. With your finite elements, and compare against each other in nice ways. Let's now turn to a couple of different surgical techniques. The first one is an impact test, involves a hammer strike. This is a high speed event. That needs to be understood, to best control, for implant, placement. Some orthopedic, surgery, necessarily, requires, that. Pieces be implanted, using hammer blows. And understanding, the variability, of force ranges, and the durations, of those blows, is absolutely critical, for. Balancing the stability, of the implant. With, without risking that bone fracture. So the objective of this simulated, test was to show our ability, to monitor the hammer strike. Including the six degrees of freedom. And bullseye, the location, temporally, and spatially. When the hammer precisely, hits the impactor. So let's go ahead and take a look. Here we are in trillion labs, with the high-speed, air mass setup on a tripod. With lighting. Mounted above you'll see those lights up there, and for this project. We optically, scan the hammer, and the impact we're going to be using you'll see our ae use that, we scan them ahead of time to get their actual meshes we want their actual shapes. So that we can tack them to the target dots we're using i explained those targets as before. And with them tacked together, the aramis will track the target dots so the mesh will move along with as you can see here in this mesh tracking. This is important because it allows us to track three-dimensional, parts even when we cannot see them. And if we know where the target dots are at then we know where in space the mesh is at. Here we have a displacement, measurement, we're measuring, length change between the hammer and the impactor. The z direction is pointed up towards the hammer, and becomes zero in the diagram, on the bottom. As the hammer hits. We selected a point on the hammer to track velocity. And this time i'll call your attention to the y direction which is the center diagram.

Directed, Positively, to the right. The hammer starts out at 1.7. Meters per second then quickly swings negative in the z direction. To understand the six degrees of freedom, we use the impactor, as a reference again using that rigid body. And monitored, the hammers, rotations, at impact. You can see most of the rotation is in the y direction, after the hammer impacts. Take a, little bit closer of a look at the trajectory. We can understand exactly the route the hammer travels, and see some of that bounce back, after it strikes. So we really understand the motion, of anything we want to see. We can also project, the hammer, mesh. In its relation to the impactor. So we're tracking it to see where in time the two meshes meet, physically. At that strike position we actually see the two meshes, as they, as they come together, and right when they touch we get a bullseye, impact point. And we can precisely, locate, that. Temporally. As well. It's pretty cool and then we've got a nice looking, measurement there. So that was pretty fast we went through that very fast. So let's slow down a little bit. And investigate, a ladder j procedure. A procedure, used to treat, recurrent, shoulder dislocations. With a bone graft you can see the bone graft screwed in here. This procedure, is performed for patients, whose shoulder is very unstable. Dislocates. Often. Becomes damaged over time. Dislodges. More and more. Results in a lot of bone loss, and. Forces the procedure. To restore the rigidity, to the shoulder, and prevent it from dislod, locating, further. A surgeon will graft bone into place often using screws to fix it into place. Ultimately, the goal is to have improved stiffness, in the shoulder. So. This test was an investigation. Into what fixing, method worked best for the least amount of deformations. Into the bone segment and the connecting shoulder blade. This was done with artificial bone material you can see in the red square down below there. And we conducted, a comparison, across. Different fixation, techniques. For motion and rotation, analysis. And we set out to detect the areas, with the largest deformation. So lots of different uh, inspections. Being made here of course we're shooting in this holistic, manner again so we're going to be able to make all those types of inspections. We use target dots on the screws. For displacement, information, and the speckle patterning, on the bone for strain analysis. There's, cyclic, loading, on the bone segment. With the two screws, until we have ultimate failure of the part you can see the very end here the video. Just. Starts to. Peel back and break there you go. And the yellow box here, you can see we have, the strain analysis. On the artificial, bone. In the purple dots the purple target dots these remember these are just sticker dots we put on. We're using these as reference, for our measurement, so we put these dots down. On the shoulder, and this is our rigid body motion compensation, you might remember i mentioned it earlier it's a feature in our software that allows us to remove global motion from our measurement. And isolate the movement of the, of the fixture. The red dots are the target dots on the screws. You can see there. And the yellow dots are the target dots on the humerus, bone, that we saw earlier that was, loading. Cyclically. So hopefully this all kind of makes sense now. So let's take a let's take a closer examination, here we have the major strain analysis. Which shows concentration. Of strain. Near the top screw. Just before. Failure. Run that through once more so you can see that. And we've got a couple of points plotted, down here. Our software is very easy to work with, we plot down points. And then we uh and. I can ask it to inspect for. Principle, or directional, strains. And, so here we've inspected for major strain, and the software, automatically, diagrams, the strain and time for us at these points on the right you can see the red, arrow headed over to the graph. We see in point two, the green line in the top graph. It's experiencing, higher strain, levels. About point five percent, more strain, during peak load and you we have the load being brought in at the bottom of course we always, like to, correlate, all our data together we have a nice controller, to bring in up to eight different channels of data.

To. Bring it all and sync, it together. So. Another way we can visualize, the results is to look at the major strain direction arrows so we see that flow of strain. You can see the compressive. Deformation. Where we have the punch it's just transforming. The load. Onto the bone segment right there. Pretty cool looking. Visual. Next we have the motion analysis, on the two screws. The target dots on the screws enable us to look at the six degrees of freedom for each one. Here we're examining, the rotations, in the z direction. That's towards the screen, let's take a closer look at the comparison, between these screw rotations, so this is an interesting, analysis. Let's look to the diagram, on the right to understand, it a bit more the top screw, is shown, in, the black, line, and it experiences, a lower level of rotation. But the blue line at the top. Is represented, of the bottom screw. You can see that it it experiences, a higher level of rotation. And. Remember that's in the z direction. So that slight upward trend. You can see in the in the blue line is the screw, loosening, itself. And so this was actually interpreted. As the bottom screw loosening. And the top screw tightening. Because the screws. Rotate, in opposite directions. This is a very unique measurement. Very interesting to see us go through this and look at strain and displacement, like a rotation six degrees of freedom put it all together and really understand, what's occurring. As we load this. Artificial, bone. And uh brought together really nicely there. I'm not going to take a break and turn things over to dr elise martin for her studies in the micro motion analysis, so i'll give up the controls, here, all right thank you. Um so today i'm just going to talk a little bit about some of my research. Concerning. Biomechanical. Analysis. Of reverse, total shoulder. So here's a simple, illustration. Of the shoulder, which is a complex, joint with several articulating. Surfaces. Our primary focus in the study, is on the glenoid, side of the glenohumeral.

Joint. When we look to replace, diseased shoulders, there are two main types of replacement. As shown here, the anatomic, total shoulder which attempts to mimic the anatomy, of the natural shoulder. And a reverse, design. Which. Reverses, the ball and socket in order to alter the mechanics. Both designs work to improve shoulder function, and reduce, pain in different. Scenarios. For this study, we focused, exclusively. On the reverse total shoulder. As you can see here this type of implant, is made up of three main components. The glenoid base plate the glenosphere. And the humerocop. Our goal is to quantify. The, initial stability. Of the glenoid, base blade. More specifically. We would like to perform analysis. In the presence, of a defect. In the glenoid, surface. This is because rotator, cuff tear, which is a common indication. For reverse, shoulder arthroplasty. Can also cause superior, glenoid, wear, prior, to corrective, surgery. As shown in the figure on the right. Some current methods, available, to treat glenoid defect. Are listed, here. Our focus, is on the use of an augmented, base plate which is a newer solution, used to compensate, for bone defect. By filling the defect with metal which is built directly, into the glenoid, base plate component. Both clinical, and biomechanical. Data is still limited for these new augment designs. The objective, of this study is to investigate, the biomechanical. Properties, of an augmented, base plate compared to a non-augmented. Base plate in the presence of a superior. Defect. So for this particular, study we utilized, a 20 pcf. Solid rigid polyurethane. Foam or sawbone. Bone substitute. Which was machined to model the glenoid, either with or without a superior, defect. The mechanical, properties, of this bone substitute. Mimic the concellus, bone of a typical. Rsa, recipient. The images below, show the anterior, and superior, view of the two types of sawbone, that we that were machined for this project. The implants. Were then implanted. Into the sawbone, material, and spray painted to allow for accurate 3d, dic, measurements. The shoulder system utilized, for this work is the comprehensive. Reverse shoulder system. The exact dimensions, of the screws used and the selected, glenosphere, parameters. Are listed here. Each testing group included 10 samples, with group a being control group with a non-augmented. Base plate and no defect. Group b including, a non-augmented. Base plate with defect. And group c including the augmented, base plate with, defect. The testing method utilized here is based on previously, published work involving, a cyclic, application. Of 0 to 750. Newtons, of force, at 1 hertz for 5 000 cycles. The applied force is directed, at a simulated, 60 degree angle of abduction. As indicated, in the left image showing the anterior. View of our setup. In this image the glenoid, component with attached glenosphere. Is held rigidly, within our support construct, on the bottom. And the appropriate, cyclic, force is applied downward, by the humero, cop. The image to the right illustrates, the basic setup of our system, including the actuator. Load cell. Specimen. And 3d, dic, cameras, directed, at the superior.

Edge Of the sample. Data was collected, in 10 cycle data sets periodically. Throughout the 5000. Cycle trial. We utilized, a 3d digital, image correlation, system, to collect data, rather than mechanical, displacement, gauges such as lvdt's. This allows us to track the three-dimensional. Position, of every point on the visible surface, of the construct. In this image i have provided, an example, of the type of image we are able to collect with the camera system. And have highlighted, areas of interest, including the base plate in blue. The sawbone, in green and the support structure, in purple. Although. 3d, dic, provides a large data set for us to work with we have chosen to focus on point displacement. To simplify, the results. These selected, points are normalized, to the support structure, in order to provide global measurements, that will have magnitude. Similar to most other rsa, biomechanical. Studies, which utilize, lbdt's. So firstly, here is shown the most superior, point selected, on the visible edge of the base plate. We are able to report the data collected from this point in multiple, directions. This representation. Of the anterior, view of a sample, indicates, motions, in the superior, inferior. Medial lateral directions. As well as total displacement. As a vector sum of the other two directions. One of the limitations. Of the camera system that we encountered. Is the ability, to make direct measurements, only along the visible, edge of the sample. In order to account for this constraint, a process, called cad import, is utilized. Which allows, for the alignment, of a cad model for the specific, implant to the visible, surface, in the camera's, motion capture. Using rigid body mechanics, any virtual to point defined, on the cad file can be tracked. This method allows for the measurement, of points, such as the tip of the implant, post. Which are not easily, measurable. Using any direct, measurement, technique. Because they are embedded within the sawbone, and therefore. Not visible, without disrupting, the surrounding, sawbone. By being able to place points on all edges of the implant, we are able to fully define the motion of the implant as the force is applied and cycled. From the point selected, on our cad import we can pull off the final micromotion, values, at cycle 5000. Micromotion. Is the amount of displacement. Per cycle, this value is calculated. As the displacement, between the loaded, and unloaded, state for each cycle. Which is relevant, to the amount of loosening, the implant, experiences. Over the course of the trial. This graph illustrates, the total micromotion, values for the three constructs. No defect. Augment. And defect. For the inferior. Superior. And tip points. This. Of note when examining, the inferior, point. Of the implant. The no defect, case has a significantly. Smaller. Mean micromotion, than the defect, case. And for the superior. Point. The defect, case has a significantly. Higher mean micromotion. Than all of the other cases. So essentially. This graph, illustrates, to us that the amount of mean micromotion. Experienced, by the augmented, base plate, is somewhere in between the two non-augmented. Cases. So based on these outcomes, we can state that an augmented, base plate may provide, improved stability. In the presence of a superior, defect. When compared to a non-augmented. Base plate, but further analysis, is required to better define the extent of this potential, improvement.

So This testing protocol, utilizes. A simulated. Abduction, protocol, to test, rsa, glenoid, base plate loosening. This type of testing, attempts, to mimic the types of shear and compressive, forces, experienced, when the joint is at the angle of maximal, joint reaction, forces. A major advantage, of this type of testing, is that its simplicity. Allows for the continuous. Measurement, of displacements. Throughout the entire, test. But in order to more thoroughly, measure displacements. Of this type of, base plate, we are working to develop, a system that is able to rotate, the sample, through an abduction, arc, to more accurately, represent, the forces, experienced, by the implant, while still being able to continuously. Measure displacements. This much more complex, system will also more accurately, follow the guidelines, put forth by the astm. So the current astm. Requirements, for testing of rsa, involve three basic stages. First a displacement, measurement, is taken, by applying a shear load parallel, to the base plate, and a compressive, lobe perpendicular, to the glenoid, plane. While while the displacement, of the base plate is measured, in both directions. The sample is then unloaded, and placed in a separate apparatus. Which will rotate the sample, through an arc of motion. Finally, the sample is removed from this setup and the displacement, measurement, is repeat, repeated. The most obvious flaw of this testing, technique, is that displacements. Are only measured, at the beginning, and end of the test. And not under anatomically. Relevant, loading. So our system. Is able to follow the basic rotary, requirements, of the astm. But can also collect measurements, in real time using the 3d, dic, system. Here you can see a video of the humero, component being swung through 60 degrees of rotation, and the associated. Camera image. The camera, is able to capture, the same important features, of the construct, including the base plate saw bone and the support structure. Additionally. We can perform the same calculations. And measurements, as presented, in the previous, experiment. By performing, the same cad import, process, to define, all the points of interest. Here i have presented. Five cycles of example data. For selected, points on the cad import, with the inferior, point in green. Superior. And point in red and the tip point in purple. The top graph, illustrates. The, superior. Inferior, displacements. And the bottom graph illustrates, the medial lateral displacements. The gray line represents, the location, of the humeral, component, in degrees. As displayed, on the right vertical, axis. So there's a lot happening in these two graphs but of note, is that the superior, inferior, direction. Both of the inferior, and superior, points move similarly. And slightly out of phase with humero, component. And in the medial lateral direction, the two edge points move in opposite directions. Indicating, a toggle of the basemate. Base plate. As this rotary, force is applied.

And In both directions, the tip point experiences. Less displacement. So utilization. Of this new system, in conjunction, with 3d dic, will help dramatically. Improve our understanding. Of the biomechanics. Of reverse, total shoulder arthroplasty. And will allow for future improvement, and development, of new rsa, designs. Uh so that is it so thank you very much for having me and if there's any questions. Otherwise, i have put my email in here you feel free to email me if you have any further questions, about this. Uh research. Great yeah we will open it up for questions, now, um if anybody, has any questions, that they would like to ask at this moment. Um. You know both. Um, justin, elise. What, um. Well, i guess. How are you fixturing, the parts. That you wish to scan. I don't know which one of you wants to answer that or if both of you want to answer that. I think that um. Maybe uh, for elise. She. Kind of had uh her set up her fixture, there. Uh, kind of. Kind of out in the open but uh for the things that we're doing. Uh we we typically find ourselves, on load frames, as much like elise is here um. For fixturing. And. So we we we can be. Out in the. Real world the raw, live data or we can, or we can be in a fixture, and um as long as we see it with the 3d, i see the aramis, then when we can uh, we can measure it. Yep i mean for most of the testing we do we use our mts, actuator. There's a few other instances, where we just take pictures, out about in the lab, but for the most part we're using the actuator, and just fixing everything within that stationary. Structure. And. Um. How fast, can you record, at. Um i don't know what the maximum rate is for the aramis. But we've been using we collect, images, at 10 hertz for our studies and that gives us a reasonable. Data collection. The aramis can, go up to as fast as cameras can go and so. There's really not a a stop point that sounds slippery, it sounds like. Kind of a slippery, answer here. Um, because, as you go up in. Sampling, rate you will decrease, your pixel size, and you'll have to, be forced to lower your field of view. But our integrated. Systems, go up to 2000, frames per second and then beyond that. We can find a system. That uh perhaps, could capture. The the transient, event you're trying to. Sample at it just would depend on a number of different factors. But yeah the, i guess uh. Off the cuff the sky is the limit, as far as speed. Goes. Great. Um justin would you like to continue, your presentation.

Yeah, Um. Let's see if i can go ahead and share my screen without powerpoint crashing, this time. And uh. Go ahead and pop it up. Okay good stuff. You know thank you very much elise here your research, is uh really interesting, and it looks like you're using, aramis, in a great way so um appreciate, your your. Study there, and. Hope to work with you more. I'd like to turn our attention to ct, scanning. And, zeiss and gome have. Developed, a true metrology, tool, with their latest ct scanner. So, let's go ahead and take a quick look at that i'll introduce, the ct scanner sheet which is basically, a 3d, x-ray. A 225. Kilovolt. X-ray, source. They can handle specimens, up to 400, millimeters. And here you can see its small, footprint, it fits into a, room here of course. It has to be a specially. Made area for a ct to be placed into but you can see the workstation. Here that controls the ct. And the software, and the hardware were designed together. And so. You can conduct, analysis, in real time that's very different from other ct scanners by the way many others require. Multiple other. Software, sometimes two or three different, softwares. But there's three main, development goals of the zeiss gome ct. The highest resolution. To have the highest resolution, highest accuracy, and the best usability. Of a ct scanner. And to that end um. The. Possible, visualization. Of the. The ct. Is to to be able to see. Surface defects, as small as 1.2. Micron, as you can see here that's, 20 times smaller than the than a human hair. So quite small so this is the highest resolution. I say, highest resolution, but what i mean is within the space of 225. Kilovolt, that's. At that source. In that space. We do have the highest resolution, currently. Um, you know as far as the highest accuracy. Uh you can see here we've had a third party study. To. Compare and contrast, us against our competitors. And the zeiss comb ct is found to be the most accurate. In that same 225. Kilovolt, space. You can see the deviation, here for, uh accuracy. And then finally, usability. And. So for. Usability. We developed, a five-axis. Positioning, table. For processing. Speeding up the scans, and the software has a number of built-in, inspections, that really set it apart. But don't take my word for it let's uh, let's go ahead and take a look i've got a short video here on the ct, and a nice introduction, to it.

And. So uh here's our ct. And uh our lovely model. Hallie can be seen loading in. A specimen, she's to open up the ct doors. And she's going to load in an animal bone that we have here it's uh. On a foam fixturing. So we're just using foam here it's easy to set apart that foam from the bone. Uh just, very different, densities, there. And uh. So, we actually use a roadkill, animal bone here none of our colleagues, would lend us a cadaver, bone. Once activated, you can see the ct, automatically, will position the part we've got a webcam, inside the ct so you guys can be brought in on the inside, and see what happens. We'll begin uh. By putting in position and begin scanning right away you can see we've sped up the tape here but uh, it was just over four minutes to scan the entire bone, this bone was about 13, inches about 330. Millimeters. This is quite fast and you can see it spins around and it's taking photos, x-rays. Once scanned. We can, get a nice look at it here and sort of spin around this is our software. And, we're going to go ahead and construct. A plane. And, a viewing plane. In which we can do some fly-throughs. And. You can see here can turn turn on the side and drag this plane through. The specimen. And. That cross-sectional. Data. Can tell you quite a bit about. This the specimen the bone here. So we actually scan the the same bone again. After drilling a small hole into it you can see the small hole there, and look for the hole again in this scan you'll see it pop up at the very top right. There there it is. We did another fly through to look at that hole in the surrounding, material. It's a perfectly, drilled empty space, uh with no effect on the surrounding, area, uh our thought was that we would drill and get some some residual, changes and structures around it, but this is a boiled bone and it was very brittle. And uh the scan. Still resulted in some really nice high resolution, images as you can see there. An inside look reveals, the structures, prevalent, through throughout a bone look at all these. Caverns, inside there you can see where we drilled on there too. One of the inspections available in this our software allows us for the volumetric, analysis, of voids. Where we can actually. Look into, the. Volume, of those voids as, the template shows. We can even take a slice of the bone material. And look at the average, thickness, displayed. That's really useful when analyzing, fracture repair for instance. So that's a kind of a nice introduction, to our ct, and hopefully, uh makes a lot of sense. I'd like now to focus on a motion analysis, project. With a spine. That. Brings together a lot of the themes. From today. And incorporates, both the aramis, and the ct, together. And so we've seen a lot of testing. With consideration. Of implants, into the spine this, we work with many hospitals. That, consider, this for. 3d printing of vertebrae, even, discs. And so, um. The following test was to analyze, vertebrae of the spine and to understand the motion, of a normal spine. Spines are impressive, structures. In terms of flexibility, and stability. And they transfer the load and undergo, various motions and rotations, and so, having the arum is being able to. Capture it all is is going to be great so let's let's take a look. So here's the video. That we captured, the spine motion, you can see target dots, were applied directly onto the soft tissue. That's overlaying the vertebrae bones, and onto the fixture, as well so you can see them even on the arms of the fixture. And so remember these are just lightweight, dots that were sticking on there that the software, automatically, identifies, and tracks, as 3d coordinates. There's also pins, that we stuck stuck. Into the spine, and you can see in, the zoomed in photo here. On the upper right. The target dots were applied to the pins, these pins. Give us structures, that move in the same way, as the individual. Vertebra. That wouldn't otherwise be visible, right so, uh with the target dots on the pins we now have information.

Representative. Of the vertebral, bones, inside the spine. This is really, really kind of cool so we've got three different sets here of dots. And after we we acquire, the images. We sort of uh cluster, them together, and select them and create different point components. For the motion analysis. So these clusters of target dots. We'll look at the vertebra, individually. Or together, or. We even have a special interest in this case. To investigate, the relative, motion between. Two different vertebra, and we'll be looking at vertebra one inverter, two for that uh. That, investigation. So with gom there's uh, there's always this capability. Of importing, in other data for alignment. Uh cad data, feat data. Uh you saw before we brought in the the scanned, mesh data. In this case we're bringing in the ct, scan data. And here. When we bring it in and align it with our project for tracking, it you can see the coordinate system is brought in with it too, this is a really nice visualization. For. Us, to be able to see what's occurring. Um. But it also allows us to track things that we wouldn't otherwise, see. The points displayed in red, are used as a reference, the very bottom there you can see it. For it's it's uses reference for the motion of the whole, test setup, and it's going to become our rigid body motion compensation, i mentioned that before. Uh and then this way we have the motion of the spine isolated, from the fixture. In the video now you can see the inspections. So you have these vectors. 3d vector displacements, on each of the target dots. And yeah it's a nice overview of the whole spine here, and. Each of the vertebra. And how they move relative to the bottom fixture, during the test. On each of the vertebrae, we place we place a local coordinate, system. And so that we can inspect for the six degrees of freedom and you can see here. Where we're. Looking at those reference, positions. And then we take take into consideration, the motion between them. To take that step. One step further. Um. We're inspecting, the rotation. In the x direction. For each vertebra, one and two remember i said we're going to look at the first the top two vertebra. This is their role rotation. And through a custom inspection, in our software we have the capability. To make a unique measurement of the difference in rotations. So. The difference between the two that is that red line there. And um. It's automatically, calculated. Throughout the test in our software, so. Uh, i think it does a good job on the left hand side pointing out that red line and how it's being calculated, between the two local coordinate systems. Using that information. This type of. Advanced, inspection. We can now. Combine it with the ct data. So, aligning with the scan data with the spine. We have an automatic, calculation. Of the position, for. Each vertebra. And you can see that the movement here embedded. In that uh that positioning. And so, we can then calculate, this is very very cool. We can calculate, the distance, between the vertebrae. As well as determine, the dynamic, disc, thickness. Throughout the test. And if you look at the color map here on the vertebra. It's actually showing the distance. To the upper vertebra. So it's this is the second one. Measured in relation to the the top vertebra. And it's calculated, as we move through the image series of the test. And so that we can see how. That this. Thickness is, is affected. As, uh the spine, is has, moved, in the fixture. So this is really really cool it really does pull it all together pulls together the ct data and the arms data, uh measuring what we can see with uh. What we previously, scanned in an understanding. Of that disc thickness. Pretty cool project, um i'm happy to be proud, proud to be part of that, um, there are a number of projects that not gotten to show you today. Uh these are the ones that we went through today but often. Our projects are driven by customers. And. So please reach out with any questions. To more critically understand, 3d optical metrology. And. We'd love to be able to uh. Help you to. Learn more about the technology. Its limitations. And what it might be able to do for you. Uh but please remember these takeaways, from the presentation. And we're highly precise, so that we have the ability to detect, micro motion we saw that with the lease. We're not contact, so there's no influence on the specimen. We can detect, the six degrees of freedom we should just sew that really nicely with the spine. We can definitely look at the relative motion between components. We saw that uh, with uh. With the spine as well. We have the ability, to, we didn't get too much into it but we get into high cycle fatigue. And we can align with. Other types of data. Whether it be for a coordinate, system. Or to see things that we sometimes, or otherwise, could not see.

Please Go download the free software, at. Where you can, access, 3d sample projects, and and, learn more about the types of inspections, you can make. And thank you so much for your time today i really appreciate, it. Great thank you both. Um. Do you have some a question, here. This is for justin. Does, does aramis, create, those 3d meshes. Of the sample parts being tested. Or were those created, in some other software, and uploaded. Yeah so the the 3d meshes that we brought in for the hammer, and the impactor you saw previously, were scanned by an atos, that's a gom atos, that we, used to scan. And uh so we scanned the parts, and we brought them into the amherst, project. The aramis, uh, project. Was for the tr. We tacked the mesh onto. The target dots, and we were able to. Track the mesh. Throughout that project, using. Aramis. What is the accuracy, of rms. Uh i guess the probably. An easy way to think of it uh and it's a little loose but uh for a meter. Field of view we we have a sensitivity. Or resolution. Of. About. 20 microns. And at 100, millimeters. We would have a sensitivity, or resolution, of. 2 microns. And we're going to be much more, accurate. Than say other conventional. Sensors, because we're uh we don't have any kind of user. Variability. We, were non-contact. So we're going to come closest, to the actual. Values, that you should see. And um but through third-party testing we've been shown to be more accurate. Um, but yeah um. Hopefully that gives you an understanding of our resolution, or sensitivity, sometimes these words are thrown around a little bit. Um, but uh hopefully that does. Well. What is the precision. Of the gome ct, scanner. Uh. It's going to have uh. It can go down to 1.2. Micron. Resolution. And, we saw it had a an accuracy. Of a three micron. Uh, deviation. You know just a general, question. You know potentially, for both of you, how do you recommend. Staying, up to date on what's happening, in, biomechanical. Testing. Well i i i could probably go first. Maybe elise has a different answer, for, for us, um. We stay on top of things, largely, through, uh direct customer, contact, we have a lot of notable customers, that uh, are are on the front lines doing really amazing, things. And so we hear a lot from them as to what they're trying to do and uh, how we can help them so we learn a lot that way. But i would say, um. I i read a lot of uh, white papers research papers. And, try to stay up to date as best as possible, through, uh colleagues, and i follow a lot of really cool researchers, to try and stay up on it. Yeah i mean i would have a similar, response, that for the most part it's, staying up on the literature, and seeing what other people have done. Um is primarily, how i make sure that we're staying up to date on what others are doing. Okay. How, is the speckled, pattern, applied to the soft tissue. And if spray, painted, are there best practices. For, preventing. Tissue, drying, artifacts. So you can use. Just standard spray paint we've used it on spines, before, or, soft tissues before and it's worked. Sometimes, you have a solution, where you might need to. Mix in. Powders, or. Use some some sort of. A different type of. Stain, to get get yourself a pattern. And there's a lot of different ways to go about this. Um, but it sounds, like intimidating.

Uh To do, but it's actually uh. Quite easily. And that's because. The software, works. Well, on any kind of contrasting. Pattern, oftentimes. Uh you can track things, already, because they'll have a pattern to them. Uh we pattern, with, spray paint, uh airbrush. And, uh. Aluminum, oxide, of of different sizes. And we find ways to to optimize. Our, tracking methodology. Our pattern methodology. But a lot of times we can just track it uh, already. Great. Well, thank you both i think we are going to wrap it up there thank you justin, thank you elise for sharing your expertise, and experience. For the audience you have their contact, information. If you have more questions. Certainly, want to. Thank trillian, for sponsoring. And, speaking, during this webinar. And of course want to thank. Everyone who attended, today. I think the discussion, provided, great examples, of how the technology. Works and i really appreciate, how both of you walked through specific, orthopedic. Applications. For our, audience. Of course we would like to hear the audience, thoughts as well on the presentation. So attendees, you will be receiving, a link, to a survey. Asking for your thoughts about today's webinar. And, additionally. You will receive, an email with a link, to, access, this webinar, on demand. So thank you both, so much. Again, thank you everybody for attending, hope you have a great. Day. You.

2020-11-19 19:29

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