My five year old came home from school the other day talking about how the shortest distance between two points is a straight line. That got me thinking about how a straight line might be the most direct route, but it’s not always the best one. For example, pilots fly around large thunderstorms because it is safer for the passengers…and the crew! So safety becomes the over-arching factor when determining the flight plan, even if the diversion uses a little more gas.
Medical devices are in a similar position of requiring a consideration of human lives. Therefore, linear thinking is probably not good enough when developing a new device. We must transition to the non-linear realm if we are to bring the safest devices to market.
Non-linear analysis will allow us to make great leaps forward in our understanding of device performance. But this will require us to cope with modeling complexities that may or may not have been dealt with in the past. Let me mention three typical sources of non-linear complexities: Continue reading
There are many fascinating medical evolutions that designers and engineers will discuss next week at the Pacific Design & Manufacturing Show in Anaheim, CA. Let me share one example, among many, for which engineering simulation plays a key role.
Advances in Implantable Medical Devices
With the world’s population aging, we can enjoy interacting with our parents and grandparents much longer than previous generations did. What is really even better is that their quality of life is improving. Today we can continuously monitor conditions that typically affect the elderly, such as heart malfunction, fluctuating blood glucose levels and hearing troubles. In fact, some implantable devices — like the implantable cardioverter-defibrillator (ICD) that corrects heart arrhythmia — connect to the web so they can immediately and transparently call for medical assistance if there is a sudden change in the patient’s health statistics. Continue reading
As the ski season gets into full swing, friends who recently suffered a sprain or had a total hip arthroplasty (THA) (implanted hip prosthesis) are wondering whether they will be able to hit the slopes this year. Did you know that 400,000 American had a THA this past year? How long after a THA must they wait before skiing? And beyond that sport, before they are jogging or biking again? Most doctors offer a conservative approach, allowing for full recovery before pursuing such rigorous sports. Their judgments are based on the average recovery of a large group of patients, throwing in a reasonable safety margin to try to avoid joint deterioration.
If you’ve had to endure the seemingly never-ending recovery period of THA, you’ve no doubt felt the frustration of feeling perfectly fit to go skiing, probably just before the season ended. Too soon, according to doctors’ recommendations. But let’s imagine imagine a more hopeful scenario: that your doctor could evaluate (for you as an individual patient, not an average) whether the risk of injury practicing your favorite sport is indeed real. Will the exercise induce too large a movement between bones and implant, thus preventing proper healing? Would the stress in your weakened ankle be too great, leading to a new injury? Could you at least start some light training again? If only we could estimate the exact stress induced by various movements in the different parts of the body, we would know for sure if we can get back in the game or need to rest further. Continue reading
In recent years, I’ve come across a number of cases in which engineering simulation has been used in medical treatment for real people, all in various ways. It is no longer confined to research laboratories for demonstration purposes. Roughly speaking, these scenarios correlate the functionality of a living organ to a corresponding machine, such as a heart to a pump, bones to beams, and so on. Thanks to advancements in simulation technology, millions of people today have been cured in a way that is much better than once thought possible.
Now I am perplexed by this thought: How far could this analogy go? I got one answer while reading a featured story about employing simulation for cancer research on the Texas Advanced Computing Center (TACC) site, written by Dr. Suse Broyde, a biology professor at NYU. Continue reading
In a previous post, I discussed how CFD can help to save newborn lives. Today, I will focus on another advancement in medicine that is generally based on the same approach: patient-specific CFD studies to treat disease. The Chiari malformation is a malformation of the brain that can cause headaches, fatigue, muscle weakness in the head and face, difficulty swallowing, dizziness, nausea, impaired coordination, and, in severe cases, paralysis (source: “Chiari malformation: Symptoms.” Mayo Clinic. November 13, 2008).
What physicians discovered is that this malformation alters the dynamic movement of fluid in the brain. This alteration is the cause for all of the malformation’s side effects. It can be corrected by a surgery that has a 70 percent success rate. This is good, but not good enough. Continue reading
I came across this USA Today article the other day about how knee replacements are on the increase among older adults. In fact, from 1991 to 2010, a whopping 3.27 million people age 65 and older have had total knee replacements. Also, the amount of time in the hospital has decreased from 7.9 days to 3.5 days.
This means I’ll be dealing with a lot more of the elderly jogging past me on my runs, hitting overhead smashes at tennis or giving a mean crossover dribble/layup in basketball.
Guess who I have to thank for making it possible for the elderly to continue their dominance over me? If you guessed ANSYS, I’ll give you a high five.
I have two examples I’d like to share with you: Continue reading
Just like me, when you’re faced with a possibly serious surgery, you might feel uncomfortable — maybe even anxious. But unlike most other patients, we experts in modeling think it would be great if surgeons could have access to simulation to see what’s actually happening in our bodies before they cut into us. Through the use of computer-aided surgery, medical teams could even train on “virtual clones” of ourselves, so that on the big day they’d be more prepared and confident in reacting to any situation, planned or not.
A team at the University Hospital of Rennes, France, led by Dr. Antoine Lucas didn’t hesitate to embrace such an opportunity. This team performs endovascular surgery to treat abdominal aortic aneurysm (AAA); a well-known solution involves implanting a stent graft. To minimize the risk of post-operative complications, the accuracy of stent graft positioning is crucial. The medical group scans the patient’s cardiovascular system at rest to gain insight about what they will encounter once the procedure starts. But during the surgery, the cardiovascular system gets deformed by the introduction of the wire guide and the stent — so releasing the stent based only on at-rest geometry could be less accurate. Continue reading
I had been thinking for a while about writing a blog on medical care and how engineering simulation (or CAE) can really help patients and surgeons. With the Supreme Court’s recent verdict on healthcare, it reminded me to do my part!
Over the years, I’ve seen numerous presentations by my colleagues and others about the use of simulation to design blood pumps and other devices, for research in drug delivery using inhalers, or even in the human eye, all simulating physiological phenomena. What recently captured my attention was a presentation by our resident biomedical expert, Marc Horner, at the ANSYS Confidence by Design workshop in Minneapolis on May 8th. Marc showed how these tools can help compute the risk of bone fracture in individual patients and how an orthopedic surgeon can narrow down choices for hip replacement. Continue reading