We're talking about moving heart surgery to a whole new level right now. It'sgoing to be more precise and give doctors a better idea. Is this what 3-Dprinting will do?Dr. Wang: I'm very excited about what 3-D printing can do. It can revolutionizewhat we do today in terms of medical device innovation and finding newtherapies and strategies to treat heart rhythm problems. It enables us to beable to take a concept and translate it into a workable model that we can usefor testing. We are trying to design a new tool; we want to really test it onthe bench. We really don't have a 3-D capability to do that at the presenttime. This allows us to take a real heart size model with its complexity ofstructure and to use the design that we've made and then to see whether thephysical and mechanical constraints are adequate to operate within thatenvironment. So, that's something that we would have to do experimentallybefore we get to patients. Then, eventually we can figure out whether that willwork in patients.
Was the before model like a hard model or what was it?Dr. Wang: Prior to having realistic models we couldn't tailor it to thedimensions of the patient, the types of heart disease, etc. We have thatpotential at the present time. It allows us to be able to have the realdimensions and real detail in terms of structure.
When you talk about experimental devices, what kind are you talking about,catheters or valves?Dr. Wang: The full range of different therapeutics and diagnostic capabilitiesare all suitable to using 3-D printing and 3-D printed models. That could becatheters or it could be artificial valves, valves that you introduce throughcatheters, or other devices that you might implant in the heart.
Do you see using this before every heart surgery?Dr. Wang: There may be a lot of circumstances where we will actually tailorwhat we do to the actual structure of the heart. We're not there at the presenttime, but that is a potential for the future. Also, we could design tools thatwould be able to be used in a specific set of conditions in certainstructures.
What are these 3-D hearts made out of?Dr. Wang: They could be made of a variety of circumstances and indeed that'sreally where some of the biggest innovations are. Currently we use a relativelyeasy to use hard material, hard plastic material. In the future, they'll bemuch more textured, they'll have other capabilities. There are structuralelements that can be used to grow cells on, things that will get incorporatedinto and dissolve over time. So, those are things for the future that are beingdeveloped now.
When you look at these 3-D printers, there's no blood, no heart beating so canit be that close to the real thing?Dr. Wang: Sure. There are definite limitations. It is not going to show you theability of the muscle that contract and that kind of thing. At the presenttime, that's certainly the kinds of models that we use. If you can look at thecomplexity, the detail of what we have is extraordinary. I've never seenanything like this in some kind of model that we can use. As I mentionedbefore, what is really important to us in designing new devices is the relativedimensions and positioning of different parts of the heart, whether it bevalve leaflets or different muscles. It's very hard to get that from an imagethat you might see on a screen and when you can actually put a device insidethe heart and see how it behaves, that gives you a whole other set ofconfidence it's likely to work in a human.
Is every heart different?Dr. Wang: Every heart is clearly different and they have very differentdimensions and relationships. When we consider that, we take account of thoseand make adjustments based on what the characteristics are. That is part of ourdaily practice, to make those adjustments. We don't have that same abilitywhen we're designing a device. The device generally is going to be fixed in itsdimensions. We have to be able to account for a lot of those variations aheadof time and to be able to see what the capabilities are.
Right now you are looking at scans to do all this?Dr. Wang: Currently we use data predominately from imaging scans that we have.In the future we can do a lot of other things, obviously. We also use theability of computer assisted drawing programs, which are used for architectureand other engineering design programs that can allow us to position within theheart devices that we've made.
With this 3-D printer, you take that information from the same scans. Is thathow you get this?Dr. Wang: We certainly can start with a scan itself and then generate theheart, but also what we'll do is take mechanical drawings and actually create amodel of the device we're creating. Then we can merge the two to see whetherthey fit, whether the dimensions are correct, and how they'll interact witheach other. It is really an important, exciting way in which we're able toadvance technology that we couldn't do before.
Could you explain to me how you get to a heart like that?Dr. Wang: We take the data set from the image and then have to refine it sothat you actually only get the area that you're interested in. Essentially theblood pool is invisible in terms of looking at the heart model. We only get thestructure of the heart. So, there's a process. It currently is very laborious.It would be hard for us to say with every patient that we see to create apicture of their heart and print because it's so laborious to get it to thatstate. In the future, that will become streamlined and we'll be able to havethat capability.
How long does it take to create a heart like that?Dr. Wang: The actual printing is relatively fast. It can be done in a matterof hours. So, we would leave it overnight, we can even get a complex modelovernight. The tedious part is actually teasing out the parts of the image asprecisely as possible, so that we can get rid of the extraneous informationthat we don't want printed. That's probably the most tedious part currently.
What's that made of right now?Dr. Wang: It is a special hard plastic that is one of the most commonly usedsubstances in 3-D printing.
Just looking at this, I would think that this would be instrumental ineducation. Would it be?Dr. Wang: Absolutely. I think we have a whole host of different applications in3-D printing that we have not even tried. One of the other aspects is to beable to have them understand how different tools can be constructed. In thepast, for example, we might create a diagram and you would say, okay well let'ssee if that might work. Now, overnight we can get the parts and see whether infact that will function. You will be able to really test whether your owndesign concept can really be translated into effective practice.
Have you used this yet in practice?Dr. Wang: We use it mainly in device innovations. We do this all the time. So,in the past if we wanted to create something on a very small scale to generatea working apparatus, I would go to a machinist and give them thespecifications. Then, maybe I'd have it two or three months later. Here we cansimply go to the computer on one of these assisted drawing programs and then wecan actually create it. It basically pops out and we get to work with it thenext day. It allows us to iterate in a very fast way so that over a series ofdays we can then see whether the concept that we've then adjusted and alteredwould produce the outcome that we want. It might have taken months or even ayear in the past to be able to get to that point. We have a real ability toaccelerate the pace of innovation and that's one of the most exciting thingsabout 3-D imaging.
As a surgeon, do you have a device that may not work as well as this?Dr. Wang: Well, certainly we always go through an iteration process any time wedevelop a new tool and so that's going to involve many, many steps of testingfor safety really to make sure it's effective. We want to do the best we canbefore we get to patients. We want to be able to solve the problems andunderstand better what the constraints are. The more we have the ability to3-Dimensonally deal with those mechanical and structural elements andcharacteristics of the tools we're designing the better, in my opinion. We'llget so much farther along in terms of designing.
So what's next for this?Dr. Wang: I think we are looking at new materials that we need to use fordesigning hearts, but also for tools that we make. So we're in the medicalinnovation device program and we're trying to create new designs and newtherapies for people. To have a greater range of tissue, properties, andmaterials that we use, that's really the next step for us. There are a varietyof different ways that people will start to use artificial tissues.
What do you mean by artificial tissues? Would you print this out of artificialtissue then?Dr. Wang: We are not doing this work currently, but others are and there areseveral avenues in which they're proceeding. One is that they're actuallycreating a so called scaffold, much as you would do for a shell of a house. Youare able to then have cells grow on that structure to provide a certainstructural element for it.
Is that the same as 3-D printing then?Dr. Wang: Well, we would 3-D print the scaffold or the structure in which itwould sit and the tissues then grow to conform that area.
What's this mean for everyday people?Dr. Wang: I think 3-D printing is going to be a revolution in terms of what wedo in medicine, what we do in all parts of our life. So, I think the ability totransform what we think conceptually whether it is on a page or now a screento be able to see it and hold it and work with it is really just an extensionof what we do in real life. The ability to have an object that you can hold andwork with is really something that we're very familiar with as humans. Infact, if you could argue while working on a screen it's kind of artificial;this is getting back to what I think people are mainly used to working with.We've just never been able to do it very effectively before. We could only dealwith pictures of things, copies of things that are on a screen or in a book.Now, we can actually have a real life model that we can make.