Category Archives: Bioengineering

Repair, don’t replace: developing a new treatment for lower back pain

Chances are that you, or someone you know, has had lower back pain get in the way of daily life. For some people it is merely an inconvenience, but for many, it is debilitating. In the United States, over 70% of adults suffer from back pain at some time during their lives. Lower back pain is the second-most common reason for missed work, after the common cold. Lost productivity due to lower back pain is estimated to be over $30 billion dollars annually.

Out of the myriad causes of lower back pain, one of the most common is degeneration of the intervertebral disk. The intervertebral disk is like a shock absorber between bones in the spine. As people age, wear-and-tear on these disks leads to damage: essentially only children have intervertebral disks without any signs of deterioration. By middle age, lower back pain is sometimes bad enough that people resort to invasive surgeries.

Ward presenting his research at the Graduate Research Showcase, 2019.

Ward Shalash, a first-year PhD student studying bioengineering with Dr. Morgan Giers, is working to find a better way to treat deteriorated intervertebral disks. Currently, the primary method for treating severe back pain caused by a deteriorated intervertebral disk is to either replace the disk with an artificial disk, or to remove the disk and fuse the neighboring vertebra. Although these methods are effective in relieving pain, patients often need to have the procedure redone after ten years. In addition, particularly for the method where vertebra are fused, patients experience loss of flexibility. In 2003 a new method, cell replacement therapy, was demonstrated on a rabbit. This treatment involves collecting mesenchymal stem cells from a patient (generally from fat cells), and injecting them into the gel-like material in the center of the intervertebral disk. Ideally, this process allows the disk to be restored in place. While this treatment has been applied with some success to human patients, the procedure is not yet standardized or tested well enough for FDA approval in the US. In particular it isn’t yet clear how to determine the number of cells to inject for best results.

This is where Ward’s research comes in. “The goal is to develop a method so that doctors can know whether cell replacement therapy will work for patients or not,” said Ward. An intervertebral disk consists of three main parts: the nucleous puplosus, a jelly-like substance in the center; the anulus fibrosus, stiff, fibrous walls around the jelly center; and cartilage endplates above and below.

Cross-section of an intervertebral disk. As the disk deteriorates, the gel-like nucleus pulposus leaks into the fibers of the anulus fibrosus.

Cells require a supply of nutrients to survive; as there is no blood flow into the disk, cells inside rely on water seeping through the cartilage endplates. Dissolved in the water are nutrients such as glucose and oxygen which are vital for cell survival.

Ward uses a combination of MRI imaging and mathematical modeling to study the flow of water through the intervertebral disk. From this information, he hopes to find a method doctors can use to determine the number of stem cells to inject. Ward hopes that the ability to algorithmically predict the success of treatment this way would cut down the cost of clinical trials.

Ward’s parents at the commencement ceremony in 2018. As a first-generation college student Ward mentions that his family’s support was important for him to continue his education towards a PhD degree.

Ward first came to Oregon as an exchange student from Israel. After finishing an associate’s degree at Portland Community College, he came to Oregon State to study bioengineering. He has a dream of a world where people don’t have to worry about injuries. One of his concerns is making sure that progress in bioengineering is ethical.  For example, says Ward, “How do you make sure that it’s accessible for all kinds of people?”

Along with his academic pursuits, Ward enjoys the outdoors, playing the oud, and volunteering. To hear more about Ward’s story and his science, tune in this Sunday at 7PM (PST). You can stream the show live online, or listen to the interview live on the air at 88.7 KBVR FM, Corvallis. If you miss the broadcast, you can also listen to the episode on our podcast soon after the broadcast.

In the background is Mt. Broken Top in the Deschutes Basin. Despite common belief that PhD degrees are scary and stressful, Ward believes that there is always time for adventures!

 

References:
Summary of stem cell treatment for back pain: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3347696/
Discussion of current strategies for treatment of lower back pain: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5651638/

 

 

How high’s the water, flood model? Five feet high and risin’

Climate change and the resulting effects on communities and their infrastructure are notoriously difficult to model, yet the importance is not difficult to grasp. Infrastructure is designed to last for a certain amount of time, called its design life. The design life of a bridge is about 50 years; a building can be designed for 70 years. For coastal communities that have infrastructure designed to survive severe coastal flooding at the time of construction, what happens if the sea rises during its design life? That severe flooding can become more severe, and the bridge or building might fail.

Most designers and engineers don’t consider the effects of climate change in their designs because they are hard to model and involve much uncertainty.

Kai at Wolf Rock in Oregon.

In comes Kai Parker, a 5th year PhD student in the Coastal Engineering program. Kai is including climate change and a host of other factors into his flood models: Waves, Tides, Storms, Atmospheric Forcing, Streamflow, and many others. He specifically models estuaries (including Coos and Tillamook Bay, Oregon and Grays Harbor, Washington), which extend inland and can have complex geometries. Not only is Kai working to incorporate those natural factors into his flood model, he has also worked with communities to incorporate their response to coastal hazards and the factors that are most important to them into his model.

Modeling climate change requires an immense amount of computing power. Kai uses super computers at the Texas Advanced Computing Center (TACC) to run a flood model and determine the fate of an estuary and its surroundings. But this is for one possible new climate, with one result (this is referred to as a deterministic model). Presenting these results can be misleading, especially if the uncertainty is not properly communicated.

Kai with his hydrodynamic model grid for Coos Bay, Oregon.

In an effort to model more responsibly, Kai has expanded into using what is called a probabilistic flood model, which results in a distribution of probabilities that an event of a certain severity will occur. Instead of just one new climate, Kai would model 10,000 climates and determine which event is most likely to occur. This technique is frequently used by earthquake engineers and often done using Monte Carlo simulations. Unfortunately, flooding models take time and it takes more than supercomputing to make probabilistic flooding a reality.

To increase efficiency, Kai has developed an “emulator”, which uses techniques similar to machine learning to “train” a faster flooding model that can make Monte Carlo simulation a possibility. Kai uses the emulator to solve flood models much like we use our brains to play catch: we are not using equations of physics, factoring in wind speed or the temperature of the air, to calculate where the ball will land. Instead we draw on a bank of experiences to predict where the ball will land, hopefully in our hands.

Kai doing field work at Bodega Bay in California.

Kai grew up in Gerlach, Nevada: Population 206. He moved to San Luis Obispo to study civil engineering at Cal Poly SLO and while studying, he worked as an intern at the Bodega Bay Marine Lab and has been working with the coast ever since. When Kai is not working on his research, he is brewing, climbing rocks, surfing waves, or cooking the meanest soup you’ve ever tasted. Next year, he will move to Chile with a Fulbright grant to apply his emulator techniques to a new hazard: tsunamis.

To hear more about Kai’s research, be sure to tune in to KBVR Corvallis 88.7 FM this Sunday May, 27 at 7 pm, stream the live interview at kbvr.com/listen, or find it in podcast form next week on Apple Podcasts.