Join the BANSWUG team for this year’s Boston Heart Walk!

Dear friends,


This year, the Boston Area North SolidWorks User Group (BANSWUG) has made a commitment to help raise funds for lifesaving science. The funds won’t go into someone’s back pocket. They’ll go to real, human hearts, like mine – and help keep them beating. But, just like my heart needed the help of caring doctors and nurses in 2011, I can’t do it alone. I need the support of our amazing SolidWorks community.  Please, join my team, or donate to the cause. Together, we’ll raise donations that will directly impact the lives of millions – and maybe someone you love (like me!). Register now to join my team or chip in at You’ll have a ton of fun, and you’ll help save lives!

If you’re in the Boston area, I urge you to join BANSWUG members at the walk on September 8th.  Being a walker is fun and easy. The American Heart Association provides great tools and tips, including your own personal fundraising page where you can solicit donations quickly online, and help us reach our goal! But don’t worry, you can participate even if you are unable to be at the walk in person. Simply head over to our team page and click “Donate to this Team.”  So join us in supporting the AHA’s funding of life changing and lifesaving research and educational programs at the same time.

Register to walk with us or donate through the link below!

Boston Heart Walk

September 8, 2018 @ 9:00am

DCR Hatch Shell

47 David G. Mugar Way

Boston, MA 02108



Thank you, I look forward to seeing you at the walk this year!


With heart,

Daniel Herzberg

President, BANSWUG

The SolidWorks Company That Saved This SolidWorks User

Check out my On-X company bio and design review, guest hosted over on SolidSmack!


Were you at SolidWorks World 2011? If so, do you remember the second General Session, when Jon Hirschtick introduced us to the founders of MAKO surgical? This company is using visionary robotic techniques to revolutionize joint surgery. How about SolidWorks’ continuing support of Design that Matters, the nonprofit company that designs medical devices for use in the developing world? I’d like to introduce you to another medical device company, which is using SolidWorks to improve the lives of patients around the world, as well as right here in your favorite blog.


On-X Life Technologies

On August 17th, I underwent open-heart surgery to replace a heart valve which has been defective since birth. My choices for the new valve came down to a biological donor valve (from a pig, cow, or human), or a mechanical valve. The biological valve would have to be replaced with further major surgeries every 10-15 years due to wear, but would not require blood thinners (since it would have completely natural blood flow (or “hemodynamics”). The mechanical valve, on the other hand, would be permanent, but would require blood thinners to avoid clotting, involving a not-insignificant life change.

My doctors then told me about a promising new valve from a company called On-X Life Technologies, Inc. The designers of this valve had paid extra attention to every aspect of their valve that would improve hemodynamics, and hopefully someday (once all the data come in) eliminate the need for blood thinners. Through my research of the valve, as well as my direct contact with the company, I’ve learned how they used SolidWorks to design this revolutionary, life-saving medical device.

The design of a new kind of heart valve

The designers developed three new features which would decrease turbulence in the blood flow. First, they added an inlet flare (much like the smooth cowl of a jet engine), to mimic the shape of a real valve. Second, they extended the outer valve ring, to match the natural length of a biological valve (a length to diameter ratio of 0.7, as it turns out.)

Third, they designed the valve’s leaflets to open all the way to 90 degrees, where other valves only open to 85 degrees or less, increasing turbulence. It’s possible to evaluate the amount of turbulence in the circulatory system by measuring the levels of a certain chemical, which is released when red blood cells are ruptured.

But you may be asking, if the leaflets open all the way to 90 degrees, what forces them to close? On-X has designed a special pivot which uses the drag force of the flowing fluid to initiate closure of the leaflet. The pivot it also designed such that blood never stagnates in the openings, further reducing clotting risk.

To design such a sophisticated device – with only three parts – On-X needed a powerful CAD package. They had been using Pro/Engineer until recently, but this year, decided to make the switch to SolidWorks. For fun, I decided to model a rough representation of the valve myself. You can find it on GrabCAD, here.

If anyone out there is interested, here’s a SolidWorks brain teaser for you: Given the diameter of the valve and surrounding artery (1 inch) and my systolic (115 mmHg or 15.33 kPa), and diastolic (65 mmHg or 8.666 kPa) blood pressure, can you create a semi-accurate model of the valve opening and closing? Complete with snazzy visualizations, of course.

My Testimonial on the On-X Heart Valve


If you’ve been following along at home, you know I recently underwent heart valve replacement surgery. My new mechanical valve was developed by a company called On-X Life Technologies, Inc. The company recently approached me to write a short testimonial about my experiences so far with the valve.  I replied, and my words have already been posted on their Facebook and Twitter accounts, as well as the official company website.  I wrote:


“I was born with a bicuspid aortic valve, which developed stenosis and calcification over the last 23 years. After it was determined that I needed my valve replaced, every medical professional I consulted recommended the On-X valve.  They all recommended it because it is a permanent valve replacement solution, requiring no future surgeries, and also based on the very low risk of clotting, which may someday eliminate the need for blood thinners.  The surgery went well, and since then my heart has felt much better than I expected. The valve is quiet and never bothers me, even when I sleep.” – Daniel


Be sure to watch this space for more information about On-X, as I explore the science and design of their valves. Also, it’s come to my attention that they are a new SolidWorks customer, so stay tuned for that side of the story as well.


What a Long Strange Trip It’s Been

I’m not sure I’ll ever be able to fully describe my experiences over the past two weeks. My personal style is to write a chronological story of the events that brought me here, but that’s too impersonal; too soulless. My story should be all about emotion. The pain, the despair, depression, and eventual hopefulness and clarity I’ve swung through since August 17, 2011.


Let’s start with the big picture. Pieces of me have been removed. Important pieces that I need to live, and they’ve been replaced with new pieces, made by man. I can hear and feel these new pieces working inside me, every hour of every day. At the moment, they’re working pretty well, but not perfectly. There was a complication, and something’s not quite right with my heart rhythm, but it’s being kept in check with daily medication. My rhythm may improve as I heal, or it may not. But that’s a discussion for another time. We’ll cross that bridge when we come to it.


I was lucky, I think, because I didn’t have to deal with very much pain. Partially, this is due to basic anatomy – there aren’t a lot of muscles or nerves crossing the center of the chest. But also, I’d like to think it’s thanks to the skill of the doctors and nurses and Children’s Hospital. The procedure and ensuing care I went though is incredibly complex, but the staff at Children’s did a fantastic job keeping me as comfortable as possible. It’s surprisingly difficult to figure out everything that goes on behind the scenes at a large hospital, even as a lucid, mobile patient. But I know for a fact that these people know what they’re doing.


Aside from the pain, however, there’s another effect of surgery – especially heart surgery – that had to be addressed. For reasons that no one is quite sure of, heart surgery brings intense emotions and deep depression to the surface. It’s a strange phenomenon that I was warned of before the procedure, but was completely unprepared for when it hit me. While I was still bedridden, before I was able to move or do anything at all on my own, and especially after my rhythm issues brought me down from my recovery high, I felt an overewhelming despair. I was sure that life as I knew it was over, and nothing would ever be the same. I lost all sense of time, and I was certain I’d be there forever. I needed to be out of that bed, and out of that hospital, and back where I felt safe. I was homesick for the first time since sleepaway camp when I was 8. I cried, unabashedly, for the first time in years. (I remember the previous time was during the movie I Am Legend. If you’ve seen it, you probably know the specific scene I’m referring to.) And even though I was told it was all a product of a traumatic surgery (combined with sleepless nights and a pharmacy’s worth of medication), I couldn’t stop myself, and didn’t even try. I needed it.


Now, back in my childhood home, I’ve returned to the reality where, yes, things will be different, but manageably so. I’ll take my pills morning and night. I’ll get my blood tested and my heart scanned. I’ll keep my stress to a minimum and eat right(ish). And in five or six weeks, most of the physical signs will be gone, and it will all feel like the most natural thing in the world. and I’m sure of that not only because time heals all wounds, but also because I have a wonderful group of people surrounding me, who helped me through the worst of it, and will continue to be there for me.


First and foremost, my parents, who were with me every step of the way, especially my mother, who was literally by my side for the entire 10-day ordeal, sacrificing her own comfort and sanity for me.

Second, my girlfriend Rose. We’re a brand-new couple, but she’s a wonderful human being, and kept me in a good place when I was at my lowest. I honestly believe that the emotions she made me feel are half the reason my heart has recovered so quickly.

Next, Dr. Stephen Colan and the team at Children’s Hospital Boston. They’ll be following my progress for years to come, which is a huge relief.

Also, the SolidWorks community. Our shared love of social media allowed them to keep in touch with me and send along their well-wishes every step of the way. Plus, it’s flattering to know that people all over the world are thinking about you.

And last but not least, all my friends. I’ve heard from some of the most unlikely people, including high school friends who (unfortunately) dropped off my radar years ago. It was a very nice surprise.


So here I am, getting a little stronger every day. Walking a little farther, moving a little more easily, and barreling head-on back into a normal life, whether I want it or not. I can drive in about a month, and return to work at about the same time. I’ll probably head back down to Virginia a little before then (but nothing’s set in stone). Until then, I’d appreciate some company while I recover.


Until next time,




The Little Things

It’s amazing the things you miss after almost 2 weeks off the grid…


 A full update is coming soon, as soon as I can collect my thoughts.


I’m sitting at the airport right now, waiting to board the plane that will take me home to Boston. When I get there, I’ll only have a couple days before I go into the hospital. On Tuesday, I go in early in th morning for the pre-op tests (blood tests, x-rays, echoes, etc). Based on the results of these tests, the doctors will recommend which type of valve replacement procedure I should undergo. The options are for a mechanical valve, a biological valve, or a complex pulmonary/aortic valve switch known as th Ross procedure. Then I have to go home that night and try to get some sleep. The next morning, the actual surgery will be performed. I’ll spend the next day or two in the Intensive Care Unit on a ventilator. The anesthesia will be strong enough that I won’t be able to breathe on my own for a day or so, but I also won’t remember that first day.

After I’m out of the ICU, I’ll stay in the hospital for 4 to 10 days, slowly regaining my strength.  I’ll probably be standing and walking on my own after a couple days, and once the doctors think I’m ready, I’ll go home to Cambridge.  Hopefully, by this point, I’ll be relatively mobile, and the pain will be under control, so I’ll be able to received visitors.  The fatigue will be the biggest concern at this point, since all my energy will be used for healing the incision. The good news is, since there are no muscles across the center of the chest, my pain should be relatively low, and my mobility relatively high.

I’ve really appreciated  the well-wishes you’ve all been sending, keep them coming 🙂

A Personal Update

On the day I was born, I was diagnosed with a congenital heart defect known as Aortic Valve Stenosis. Essentially, due to a typo in my genetic code, one of the valves in my heart which is supposed to have three flaps, only has two.


Those two flaps leave a large gap in the valve, and allow a significant amount of blood to leak back into the heart after it beats (known as valvular regurgitation). This means that my heart has to work much, much harder than yours to pump the same amount of blood – and therefore oxygen, through my body.


The extra strain on the heart due to a bicuspid valve eventually leads to two complications, which have only become problematic for me within the last year or so. First, the valve itself has become calcified.  Literally, the extra stress on the valve has caused calcium deposits to build up in and around it.  From the Mayo Clinic:


“With age, heart valves may accumulate deposits of calcium (aortic valve calcification). Calcium is a mineral found in your blood. As blood repeatedly flows over the aortic valve, deposits of calcium can accumulate on the valve’s leaflets. In some people — particularly those with a bicuspid aortic valve — calcium deposits result in stiffening of the leaflets of the valve. This stiffening narrows the aortic valve.”


The second complication is enlarging of the heart, due to the extra work it’s being forced to do.  From the National Institutes of Health:


“Valvular regurgitation forces the heart to work harder to transport blood. Over time, the heart muscles expand to compensate for regurgitation, leading to an enlarged heart. An enlarged heart deforms the heart chambers and causes further damage to the heart valve, increasing the severity of valvular regurgitation.”


An enlarged heart not only increases the risk of heart attack and stroke, but also arrhythmia and bacterial infection in the lining of the heart (endocarditis).


This genetic disorder is not as rare as you may think. About 1–2% of the population have bicuspid aortic valves, but the condition is twice as common in men.

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