| Week 3 | Over the past few weeks, our team has met with Samuel Brehm, our primary liaison for the Flexure Medical senior design project. These dialogues have centered on the project’s intricate technical specifications, and we have integrated insights from a diverse array of scientific sources and scholarly journals. In our pursuit of rigorous validation, we have placed particular emphasis on drawing from peer-reviewed literature. Furthermore, we have conscientiously incorporated insights that shape the project scope thereby detailing and defining the client, their needs and the relevant physiology, in particular, the L5-S1 lumbar region. Currently, we have a meeting scheduled with Shria Bucha of Sling Health to discuss the business applications of this project. Through these next upcoming weeks, Evie and Sophie will continue to collect, disseminate and detail information about the design specifications of the disk and how we can adjust these specifications depending on age and gender. Camila will look into possible materials that have been used that fit our design specifications to determine the next course of action that will be done. We also intend to establish a regular cadence of meetings with both our client and stakeholders including physicians who have utilized cervical artificial disc replacements before. This ongoing dialogue will ensure alignment with the project’s evolving requirements. We are currently interested more in-depth in what the preliminary presentation should include and to what extent we should be defining the problem as opposed to explaining our possible solutions. |
| Week 4 | This week, our team focused on preparing for our Problem Day presentation and pitch for Sling Health. To prepare for Problem Day, we researched the physiology of the L5-S1 intervertebral disc, spinal fusion surgery, and current artificial disc designs. Sophie focused on the unique properties of the L5-S1 disc, including the curvature and angle of the disc, the process of degeneration of the disc, and the population of people with an injury or disease to the disc. Evie focused on the nature and complications of spinal fusion surgery, including specific data about complications in different populations and risk to blood vessels and nerves in the spinal region. Camila looked into the different artificial disc designs currently on the market in terms of what their success rates are, how long they last, and what types of patients are eligible. We then worked together on our poster for the event, including our preliminary research as well as our contact information. At Problem Day, we spoke to a variety of medical students, business students, and undergraduate researchers about our problem and where we see our project going. We made good connections with various business students to help with the market research and patentability of our solution. We also were able to meet our client in person and discuss setting up a recurring meeting time. For the coming week, we are going to continue researching the specifics of our problem, and we are going to draft our Preliminary Report. |
| Week 5 | This week, our team focused on writing our preliminary report that is due on Friday 9/29/23. In order to play to our strengths and make the process easier, we thought it would be best to split up the report and then get together to explain all of our findings to each other. We met up on Friday 9/22/23 in order to think about how we would rework our need statement and project scope based on the feedback given by the professors and to split up the remaining portions of the report. Camila focused on the background information such as the population for the product and the current/ projected market. Evie focused on the need statement and project scope as well as the key stakeholders and the updated design metrics. Sophie focused on looking into existing solutions and finding their patents. She also organized all of our roles into a color-coded Gantt Chart. We will be meeting Thursday 9/28/23 in order to share all our findings with each other and combine it all into a complete preliminary report. We will also make the slides so that Camila can present next week. After Sling Problem Day, we had a few people reach out to us about joining our team. Evie will be meeting with one of them on Friday 9/29/23 in order to understand what he wants out of the experience and what he can bring to the team. We also attended the Sling Health Team Leads meeting on Thursday 9/28/23 and obtained some resources to help us with our project. |
| Week 6 | This week, our team focused on practicing and presenting our Preliminary Report Presentation. Within our presentation, we also added research about the failures about each existing solution. Previously, we delved deep into an extensive exploration of the various existing solutions. However we recognize the importance in recognizing the shortcomings in the: Intervertebral Prosthetic Discs from SDGI Holdings, Intervertebral Prosthetic Disk from DePuy Spine LL and an Intervertebral iImplant from Depuy Synthes Products. Furthermore, this week we discussed methods of information dissemination based on the audience and goals of our presentation. (the class, other medically minded people, potential investors etc). The whole group helped with the construction of the presentation and Camila presented the presentation. Evie has been in contact with a potential addition to the member of the team ( a member that the team met at Problem Day). However, this is an ongoing endeavor as the team needs to still check with the client. We also plan to meet with our client tomorrow. |
| Week 7 | Since our team was on fall break for the beginning of week 7, we did not do much product research or development and instead focused on setting up our website and planning for our next assignment for Sling Health. Our group met to discuss our design review deliverables and what aspects of our project we wanted to focus on discussing with the board. We are planning on explaining our timeline as outlined in our Preliminary Report, as well as the product we are planning on developing for our final prototype. We will show the existing patents and products on the market that we will be competing with as well. Additionally, we created our website. We discussed what aspects of the project would be important to include in the website and how we want to lay out the pages. We then divided up who would work primarily on each part of the website, and finished the set up. |
| Week 8 | This week our group mainly focused on the deliverables for design review 1 for Sling Health. We met with our client Sam to discuss what would be expected of us at the Sling design review as well as next steps in the project. We talked about some of the specific design requirements that he wanted us to include. He gave us some more specs about the exact stiffness and degrees of freedom that the prototype has to have. He told us that we need to be looking at some of the FDA specs for lumbar disks and to look at the SCA code for more specs. He also told us that Autodesk Inventor is fine to make the CAD model and or that we can use Fusion360. Sam also said that based on his experience in order to help with the biocompatibility we should consider using titanium. We will be meeting this Friday to finish our presentation for design review 1. This meeting will include a new group member that we met through Sling that will be helping with the CAD prototyping as he has extensive experience with that. We will start looking into solution designs this week after the Sling presentation is complete. Question: How soon do you think the CAD modeling should be done? |
| Week 9 | This week, there was a lot of ground that was covered. To start with, as our group (group 2) is a part of sling heath, we participated in a design review at the med school where we presented our plan for Revive-L5. Included in the presentation is information about the market as well as what percentage of disk replacements are from the L5/S1 region, a brief overview of the IP analysis and most importantly the Customer Interviews. Within the context of the L5/S1 artificial disk replacement, we identified three potential customers: Clinicians, Surgeons and End Users. From a clinicians point of view, we deduced that artificial disks are good options for a small proportion of patients because painful disc herniation uncommonly occurs in isolation. They also pointed out some possible parameters that the artificial disc would need to fall within to be successful for the most amount of patients. Interestingly, when interviewing surgeons, we deduced a lot of parallels between their concerns as well as clinicians. However, due to surgeons being the ones performing the surgeries, there were a lot of concerns with implementation and revisions of the artificial disk. Furthermore, when discussing with the surgeons, we were able to gain a bit more insights of what threshold it took for a patient to undergo surgery. It was also interesting to discuss shortfalls of current artificial disks on the market from the surgeon’s perspective. We found these clinicians and surgeons by leveraging connections within the WashU/Barnes Jewish Hospital System. We also discussed with possible end users their concerns about the artificial disks. These conversations were interesting as they had a myriad of background levels to possibilities of artificial disks. There was a variety in knowledge of physiology, as well as current available products on the market. Subsequently from these conversations, we plan to further meet many of the clinicians in person. It should be noted that we were incredibly grateful for the responses from these customers as we recognize their insights will be valuable as we continue to think through possible areas of concern for our project. We will continue to use this knowledge as a framework moving forward. |
| Week 10 | This week, we met with Dr. Camilo Molina, a neurosurgeon specializing in spinal revision surgeries at Barnes Jewish Hospital. Our interview notes go as follows: What is the makeup of your patients looking for lumbar surgery? Are they primarily athletes with disk injuries or older patients? Predom older 55+, spinal deformity, younger educated people looking for motion preservation -> don’t have enough severe disease for fusion or device, just decompression. What are the most common quality of life difficulties of patients who have undergone spinal fusion surgery? One level fusion imperceptible loss of fusion, risk of adjacent segment disease -> could also be natural degen of disc, fusion done incorrectly can put addition stress on other segments, everyone looking for movement, indications for fusion are tight -> have mechanical instability prior to surgery, surgery creates instability (often stress directly above, not enough segmental lordosis -> unnatural pressure) What are current artificial disk designs lacking? Biological considerations: Long term follow up, different from cervical, transfer of entire torso axial, then force transmitted through hips, requires anterior approach, minimal bail outs -> can’t go back in, if disc fails or subsides then stenosis (often incorrectly used for fusion therefore osteotomies happen at a high rate) What are your thoughts on the benefits and drawbacks of artificial lumbar disks as opposed to spinal fusion? In practice replace disc biologically, nucleu pulpos isi (restore disk height), does not want to burn the approach (disk subsides and collapses on themselves, risk of concern in lumbar spine), iliac veins at L5, peritoneum, ureter (why lumbar surgery from the front is dangerous). |
| Week 11 | This week, most of our group was out of town for conferences and competitions so we spent time thinking of what needed to be researched and dividing up some of it so that things could still get done. We spent some time going over our notes from the Sling Health design review and split up some of the tasks that they asked us to look over. A couple of the things that were mentioned were: To look into existing clinical trials to figure out how long ours would take as that it could take a significant amount of time and which would make this project a serious long term commitment. We did market research and analysis for the size of the entire lumbar disk replacement market but to find some numbers to quantify the size of the market for just that specific region. Furthermore, figure out if whatever novel design we create for this region in order to break into the market can then be reworked and used for other areas in the spine in order to expand. We have also been looking into the materials that our competitors are using in order to decide the best course of action for us. Most of our competitors are using cobalt chrome alloy or a similar metal for the endplates and ultra high molecular weight polyethylene (UHMWPE) for the core of the disk. We are looking into different materials and the pros and cons associated with using them versus the cobalt chrome alloy. Currently we are looking into titanium and stainless steel. |
| Week 12 | This week, we began initial planning for the Progress Report that is due the first week of December. We recognize that these Reports are a fantastic opportunity to show what we have been working on this semester and thus, we wanted to give it the time and effort which it deserves. Thus, we have already started to delegate and think through how we are distributing the work that is needed for the completion of this report. To start with, we revisited all of the different comments that we received on our preliminary project. There were a few things that we have fleshed out since then and thus, it was great to see our ongoing progress. We recognized that although the general structure of our presentation was well fleshed out, we need to clarify a couple of things as well as delineate numbers of impact such as the number of people in the market. Thus, we made note of information that we wanted to change and adapt in our Progress Report. Additionally, we thought out how to create a compelling Pugh Chart that would fit our product and class appropriately. Throughout the semester, we have had an ongoing dialogue with our client. This information, combined with ongoing conversations with clinicians at both orthopedic and neurological levels, has influenced our design to be effective and efficient, catering to the perspectives of both clinicians and patients. We plan to increase the frequency of meetings with our client in these upcoming weeks to ensure that we are on the same page in terms of design alternatives and chosen solutions. |
| Week 13 | Before thanksgiving break, we had delegated what each of us would start working on for the progress report, but we waited to submit the weekly report until we had come back to best update what we have been working on. For the progress report, Sophie led the brainstorm of different ideas based on the spring design our client proposed. We came up with different categories for each step of the device design: spring shape, spring quantity/configuration, attachment method to vertebrae, and materials. Sophie then sketched out our ideas and we went through multiple Pugh matrices to come up with our design. We determined our Pugh matrix criteria as a group, as led by Camila. Sophie then modeled the design in Fusion 360, and Evie and Camila began outlining the report. For the rest of this week we have been writing the report and working on our presentation slides. |
| Week 16 | This is the first week of the Spring semester. After we did the yellow stickies assignment in class we had a better understanding of the timeline that we are working with and who is responsible for what parts. We are currently in the process of trying to figure out if there is a titanium printing place in the area that we could pay to do it in order to cut back on shipping costs and wait times. If we cannot find a local one then it is very important that we get the CAD models done as soon as possible and send them out for titanium printing so we can have a better understanding of the final price and the wait times. Professor Rutz mentioned that we should reach out to Dr. Kathy Flores as she does this type of work but is there another person we can reach out to that would know where to print? We met with Sam and set out the times to meet this semester in order to get the CAD designs done and do the FEM testing. There are other real world tests that we might have to perform but we need to look into what kind of FDA testing would be required of us. Sam also mentioned that he wants to try to get a goat spine from a butcher and print a scaled down version of the device in order to get a better understanding of how the device works in an actual spine. |
| Week 17 | On Friday we met with our client for several hours to go over the FEM testing process and what changes need to be made to our 3D CAD model in greater detail. Our goal is to have a first prototype done that we can send to get protolabs to print in titanium so that we can start the testing process. We printed our first prototype in the maker’s space and realized that the spring shape that we had originally chosen does not have a hard stop due to its curve and ends up bending in the middle. We are making a CAD model in order to test a variation of design where the end is curved in order to reduce risk of snapping. We are looking into design recs that we need to change and ones that we hadn’t thought about before like the spring constant of springs and their thickness. |
| Week 18 | This week, we began to execute the plans that we are with our client last week. An interesting insight that we realized, is the variability in the published numbers for our disc parameters. A person’s disc degrades over time, and two different people who have “healthy” discs have wildly different sized lumbar discs due to genetic factors, anatomical variations, body weight and lifestyle etc. Thus, there is no consensus on what metrics should be utilized for healthy as well as degenerative disc disease patients. Nonetheless, this is an ongoing consideration as we continue to define the parameters for our product. Furthermore, as discussed in the week 17 update, we are starting to ramp up the model and design of our initial prototypes. Something that we are beginning to explore is the amount of infill to use when 3D printing. We hope to strike the balance between strength and weight so as we continue to formulate more prototypes, we will adjust these parameters. This is particularly applicable when coming to conclusions of our final designs. From the amount of infill, we can make informed decisions of our final design. This decision will determine where hard stops exist upon compression and what designs allow for appropriate amounts of bending. |
| Week 19 | This week we focused on FEM testing to determine what relationship between spring thickness, length, and width was ideal for producing the necessary spring constant. We are still working on developing this relationship, but we worked with our client to develop a MATLAB algorithm to take in our tested FEM values and the resulting spring constants to try to calculate what thickness, length, and width combinations would produce the necessary spring constant. We also prepared our slides for Design Review 3 for Sling Health. We performed further market research, determined value propositions, and discussed regulatory compliance. |
| Week 20 | We did our design review on Thursday and it went very well. We got overall positive reviews and have been working on the criticism that we got. We were told that it is really hard to get something FDA approved that is fully customizable for every person and they gave us the advice that we should probably make a couple sizes and allow the surgeon to pick the size that most closely fits the person. That way we can get through the FDA process much easier and still be able to offer different sizes to better accommodate our patients. Another comment that they had is that we should continue talking to more surgeons that perform these surgeries daily as the process continues to ensure that we are correctly putting on the features that they want and making a product that they think will be useful in the market. We have been making a list of people that we think we should talk to and figuring out what questions we want to ask them. We also continued FEM testing. |
| Week 21 | This week was a fun balance between the Sling health ideas that we wanted to implement over as well as starting the beginning stages of our verification and validation report ideas. To kick off this process, we realized that there was a lot of different information and design constraints and wishes that our design needed and wished to abide by. Thus, we needed to make determinations as to how these considerations can fall in line with our client’s needs, prospective patient’s needs as well as what can feasibly be achieved. Furthermore, to feel comfortable that our lumbar disc could be adequately implanted into a real person, we need to simulate all of the different scenarios a person may want to achieve i.e continuing all of the different ways we could adequately test our design both physically as well as the FEM testing. Lastly, we began to conduct and determine all of the different components that entail a MAUDE search. |
| Week 22 | This week we focused on the verification and validation report. We did a lot of research on the verification portion for the Sling presentation last week, so we were able to amend the information we gathered from that. We also met with Dr. Klaesner to understand the difference between verification and validation. In addition, we finalized the dimensions of our CAD model and sent it to print out of PLA for some initial testing, and we are waiting on Sling to send it to print out of titanium. |
| Week 23 | Since we are waiting for our printed file to arrive, we are unable to perform any physical testing. We worked this week on the verification and validation presentation slides and script, and came up with a timeline for how we plan to execute the rest of our project after spring break. |
| Week 25 | Our printed file is set to arrive on Saturday so we could not perform any physical testing this week. We talked about the Sling Health design review 4 and refined our timeline for testing starting next week. |
| Week 26 | Although this week was busy for a myriad of group members, we still came out quite productive. Both the titanium and the pla models of the disc are finally in our hands. As such, moving forward we will continue to solidify our plans in mechanical torsion testing and things of the sort. In other words, we are solidifying how, where and with who we can perform testing. Although to prove efficacy of our device we need to conduct animal testing, we recognize that this is out of the scope of our project given time constraints unfortunately |
| Week 27 | This week we focused on outlining our presentation for BME Day, as well as printing out our final physical version of our product in titanium and PLA. We have explored options for physical testing within the WashU Makerspace and other St. Louis makerspaces, but we have struggled to find the devices we need. We have also discussed our options to build a device that could perform the testing, but upon discussion, that would be beyond the scope of our knowledge and the timeline of the project. Our client is helping us explore our options and is discussing other physical testing mechanisms. We have also worked to update our website and organize our resources in preparation for the end of the semester. |
| Week 28 | This week, we were able to perform physical testing on our initial PLA model to determine that the FEM testing is mostly accurate to the amount of force the device can sustain, displacement at a given force, and consequential spring constant. We also began writing our final report and outlined what graphs and images we would need for our poster, so that we could divide up tasks to each of the group members and continue working on them. We finally ordered our final PLA and titanium models of our device. |