Craig Bonsignore

3D Printed Aortic Bifurcation

I first saw a MakerBot Thing-O-Matic in action at the 2011 Bay Area Maker Faire, and it was truly a thing of beauty. I’ve used rapid prototyping machines and services since the mid 90′s, but here was something that you could build yourself, and have on your own desk! Wow. Later in the year, I happened to have a free day in New York during the NYC Maker Faire, so I was drawn to revisit this hacker dreamscape. There, I met @ErikDeBruijn, one of the developers of the Ultimaker: an elegant build-it-yourself 3D printing machine capable of relatively high speeds, stunning resolution, and a comparatively large print volume. I became immediately obsessed with visions of 3D printed anatomical structures, and medical device prototypes. I asked Erik if the Ultimaker was being used commercially, and he knew of a few customers that were using it in schools, and at least one other that was offering a service making 3D prints by the hour. Medical device development, not so much. That only made me more interested.

Later that day, I saw a great talk by Bre Pettis (@Bre) of MakerBot fame (30 minute video on Fora.tv). An icon of the open source hardware movement, Bre gave lots of examples of digitized “things” that are freely shared on sites like Thingiverse, where users can upload, download, share, modify, and combine digital objects. And now print them out, too, effectively “teleporting” physical objects among like minded citizens of the internets. Digital “mashups” of Yodas, Gantstas, and Rabbits delighted the maker-faithful in attendance, while evoking dismissive comments from the guy sitting behind me: “What’s the point?” Dismissive guy, and many like him, see a toy. Which it is. But its more than a toy.

A few quotes from Bre’s talk resonated with me:

If you’re not sharing, you’re doing it wrong!

If you’re at a company, and keeping things secret… Stop it!

Publish those things (even if they’re not done, or done done)… Just share them, because so much of the future depends on it.

These are the noble words of an open source evangelist, and the principles upon which Linux, Firefox, Wikipedia, Arduino, and countless other open source projects depend. And then there’s my professional universe of medical device design and development. An industry that relies upon proprietary designs, trade secrets, secure patents, guarded intellectual property. The opposite of open. And yet, everything that we do in my industry is directed at improving the human condition, which is very much in the common interest of all humans. Is there a way to be “open” in a “closed” industry?

It isn’t easy. I wrote about the opportunity and challenges in Open Medsystems a few of years ago.  Medical device development is expensive, and it generally isn’t going to get funded unless the investors have some confidence that they can profit from their investment. So NDA’s will be signed, secrets will be kept, patents will be filed, and knowledge will be sequestered. Brilliant engineers and designers will face the same challenges, each alone in their own respective proprietary silos, not knowing of their kinship, not benefiting from each other’s ideas or mistakes. In the end perhaps one will win, or both will lose.

But there is hope. I’ve tried to do my part by publishing Open Stent Design on NitinolUniversity.com, releasing Stent Calculator on Google Code. But I think there’s a bigger “open source” opportunity for the medical device community, and I’m not alone. 3D medical imaging technologies, like CT scans and MRI’s, have made amazing advances in the last decade. These increasingly ubiquitous machines create torrents of 3D data sets, each a unique atlas of human anatomy, and each an exquisite three dimensional map of  a diseased system, organ, or tissue. These medical imaging data sets hold secrets waiting to be discovered -they describe the environment in which medical devices must do their healing work. 3D imaging data, usually in DICOM format, is easily anonymized, and easily rendered and manipulated with open source software such as the excellent OsiriX [osirix-viewer.com]. Translating medical imaging data sets into useful 3D geometry for analysis or simulation is messy work (see segmentation [Wikipedia]). But it is important, and at least one group is working on developing a Cardiovascular and Pulmonary Model Repository [VascularModel.org] to do just that. Sponsored by NIH, this effort will collect medical imaging data sets for several body systems, perform segmentation, and make the raw data and analysis available to the public.

Freely available 3D anatomical data + open source 3D printers = freely available (plastic) body parts! Rapid prototyping of proprietary 3D data is nothing new in the medical device development world… but 3D printing of freely available anatomical models derived from freely available anonymized medical imaging data is all kinds of awesome! 3D printed blood vessels, organs, and bones can be used to mold or cast realistic benchtop models, which can be used to test and challenge medical device concepts in a realistic environment… Or better yet, many realistic environments, reflecting the many individual humans they are designed to help. And that is some true open-source mojo at work in a closed industry, to be benefit of all.

So after honing my Ultimaker skillz on snakes, whistles, cars, and alien eggs (“What’s the point?”), I have turned my attention to the beloved OsiriX DICOM Sample Library [pubimage.hcuge.ch], and tackled the aortic bifurcation of the AMNESIX model. After some quality time with OsiriX, I had a rough export of the aorta and iliac bifurcation, which I then cleaned up in MeshLab [meshlab.org], sliced using Netfabb [netfabb.com], then printed using ReplicatorG [replicat.org]. And though it isn’t final, done, or done done, it is now shared as Thing:15942 on Thingiverse!

Spooky Nitinol Magic

Every fall for the past dozen years, Washington DC has hosted the annual celebration of cardiovascular medical device innovation, inspiration, teaching, marketing, controversy,  and edutainment known as TCT. During this week, leading physicians, industry brass, deal makers, and investors mix at scientific sessions, banquet rooms, expo halls, bars, and restaurants at the heart of the heart business. Every year, it seems, has at least a few memorably controversial moments.

My first TCT was not in Washington, but in Milano, Italia. The year was 1997, and I was at the cath lab of legendary innovator Antonio Colombo, along with a host of other industry folks, all hoping that this diminutive giant of interventionl cardiology would honor us by using our particular widget during a live case transmission. Alas, the unremarkable Mini Crown stent that I brought never did make it to prime time. He did, however, open the first live transmission of the conference by performing balloon angioplasty and stenting on a opera singer — while the patient belted out ‘O Sole Mio on the table(!).  This was my introduction to the Theater of TCT. Some years later, Colombo opened the conference by implanting perhaps a dozen drug eluting stents in one patient’s coronary arteries. In the opening live case of 2004, a percutaneous aortic valve procedure tragically devolved into urgent practice of CPR and defibrillator techniques. 2001 was one of the few years that I missed TCT; the conference was cut short on its second day by the events of September 11th. This year, for the first time ever, TCT left its home in DC, and came to my own back yard: The Moscone Center in San Francisco.

In recent years, the opening cases have been less flamboyantly Italian, and more conservatively Dutch or German. 2009 was no exception, but it was a highlight none the less. In the opening case from Seiburg, Germany, a CoreValve was successfully placed in a 92 year old patient with aortic stenosis. Recently purchased by Medtronic, the CoreValve device prominently features a  Nitinol frame — marking the first of many moments where Nitinol took center stage in Cardiology at TCT 2009. While Nitinol has been a headliner in peripheral vascular stenting, carotid stenting, vena cava filters, and guidewires for many years, this marked the first year where this unique material took center stage in matters of the heart.

Nitinol featured prominently in Wednesday’s Coronary Stent Design and Device Development session, which was so interesting that it prompted evacuation of the Moscone Center for an hour. Noted author Tom Duerig highlighted the unique properties of Nitinol in his Metals as Implantable Materials talk, followed by some spectacular data presented by Juan Granada demonstrating the performance of Prescient Medical‘s vProtect Luminal Shield, a Nitinol stent designed to stabilize vulnerable coronary lesions. The hits kept coming on Thursday, with over three hours dedicated to The Re-Emergence of Self-Expanding Coronary Stents, which included my contribution (on behalf of “Real Metallurgist” Alan Pelton), Important Stent Design and Delivery System Issues Make All the Difference for Coronary Stents. I joined an all-star cast including Renu Virmani, Barry Katzen, Rob Schwartz, and Stefan Verheye along with friends and fellow JJIS alumni Bob Burgermeister and Hikmat Hojeibane, all singing the praises of Nitinol as a solution for persistent challenges in coronary arterial disease. On this year that the center of the cardiovascular universe came to my home turf, Nitinol and NDC were stars at the heart of TCT Theater.