Biomimetics and Dextrous Manipulation Lab
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Tags: SummerBlogs, Profiles.MireyaVelasquez

Mireya Velasquez Summer 2025

Week Five: July 14 - July 18

This week I:

Week Four: July 7 - July 11

This week I:

  • reviewed the readings Xinyi provided to us:
    • Thesis Takeaways (mainly focused on Chapter 3): This chapter showed that it’s possible to build a physical Windkessel module that accurately mimics how blood vessels resist and respond to flow. The resistance units made from parallel capillary tubes stay stable across flow rates, unlike traditional valves which become unreliable due to turbulence. By tuning the design, the resistance, capacitance, and inductance values can be predicted ahead of time and confirmed with real measurements. The full Windkessel module worked consistently under different simulated heartbeat patterns, and the math model matched what was measured in the lab. This means the physical system can reliably represent what happens inside the body. Using this setup helps validate computer simulations (CFD) by making sure the boundaries used in models behave like real arteries. It also creates realistic conditions for testing medical devices. Overall, this tool helps bridge the gap between physical experiments and simulations in cardiovascular research.
      • Questions/Confusion:
        • Would this setup still work with real blood, or is that too different from the glycerol?
        • How do you make sure all the capillary tubes are completely filled and free of air bubbles?
    • Test Rig Reading Takeaways: This reading explains how to test a weak, pulsing pump in a fair way using a simple setup. It shows that adding compliance (like air chambers) near the pump helps control pressure changes so the pump can fill and empty properly. The fluid level in a reservoir sets the pressure coming into the pump to match body conditions. Sensors and compliance need to be close to the pump, so placement has to be balanced. A valve can be added to make the pump work against higher pressure. The goal is to make sure the pump works well under different conditions without making the test too complex.
    • Compliance Elements Reading Takeaways: This reading explains three types of compliance devices used to mimic how real blood vessels handle pressure changes. Elastic devices, like rubber tubes or balloon-like parts, stretch with pressure and best imitate natural veins, especially when simulating breathing. Gravity-based compliance uses open containers where fluid height controls pressure and volume, making it easy to tune but risky if the column overflows. Windkessels use trapped air to absorb pressure spikes, like plumbing systems, and their compliance depends on air volume and pressure. Each type has pros and cons, and picking the right one depends on the type of simulation and flow. These tools help create more realistic mock circulations for research.
      • Questions/Confusion:
        • How do one know which type of compliance device to use: elastic, gravity, or Windkessel?
  • participated in the second part of the Arduino tutorial. We used Tinkercad to begin then set up Arduinos with wires, resistors, force-sensing resistors and LEDs to read data from. A screenshot of the Tinkercad visual we modeled is attached:

Tinkercad model and code we referenced when using real Arduinos

Breadboard wiring with Arduino and relay


Week Three: June 30 - July 4

This week I:

  • reviewed the papers I have been researching and any confusion I had surrounding the Fonton procedure with Xinyi
    • Fontan Complications:
      • Mazza, Giuseppe Antonio, Elena Gribaudo, and Gabriella Agnoletti. "The pathophysiology and complications of Fontan circulation." Acta Bio Medica: Atenei Parmensis 92.5 (2021): e2021260.; https://pmc.ncbi.nlm.nih.gov/articles/PMC8689331/
        • Key Takeaways:
    • Fontan Fenestration:
      • Bouhout, Ismail, et al. "Effect of fenestration on Fontan procedure outcomes: a meta-analysis and review." The Annals of thoracic surgery 109.5 (2020): 1467-1474.; https://doi.org/10.1016/j.athoracsur.2019.12.020
        • Key Takeaways: Fenestration during the Fontan procedure doesn’t change the risk of failure or early death, but it does lower lung pressure and reduces fluid buildup after surgery. However, it also leads to lower oxygen levels, which might be harmful over time, especially in kids. The fenestrated group in this study had more complex heart conditions going into surgery, which may explain why their hospital stays weren’t shorter even with fewer complications. Overall, fenestration can help with certain short-term issues, but because it lowers oxygen levels, its long-term impact means the decision to use it should be made carefully for each patient.
        • Questions/Confusion:
          • How do surgeons decide when to use fenestration, and is that decision more influenced by norms or patient-specific qualifications?
    • Fontan Palliation
      • De Leval, Marc R., and John E. Deanfield. "Four decades of Fontan palliation." Nature Reviews Cardiology 7.9 (2010): 520-527.; https://www.nature.com/articles/nrcardio.2010.99
        • Key Takeaways: The Fontan procedure provides a life-saving option for patients with single ventricle heart defects, but it comes with long-term challenges. The circulation it creates leads to elevated venous pressure and limited cardiac output. These conditions contribute to complications such as arrhythmias, liver dysfunction, protein-losing enteropathy, and reduced exercise capacity. Standard heart failure treatments are often ineffective due to the preload and afterload dynamics. Continued research is needed to better understand these mechanisms and to develop solutions that can address the specific needs of this patient population.
    • Fontan Outcomes
      • Dennis, Mark, et al. "Clinical outcomes in adolescents and adults after the Fontan procedure." Journal of the American College of Cardiology 71.9 (2018): 1009-1017.; https://www.jacc.org/doi/full/10.1016/j.jacc.2017.12.054
        • Key Takeaways: Adults who had the Fontan procedure as kids are living longer, but many face serious health issues as they get older. By age 40, only about 40% are free from major complications like arrhythmias, heart failure, or needing more surgeries. Those who had the older atriopulmonary (AP) version of the surgery tend to do worse than those with newer methods. Men and people with heart valve problems are especially at risk for bad outcomes. All in all, growing up with a Fontan heart means lifelong care, and the road gets bumpier with age.
        • Questions/Confusion:
          • What are the key differences between the AP, LT, and ECC types of Fontan procedures, and why do they impact long-term outcomes differently?
          • How does a patient's sex affect their long-term outcomes after the Fontan procedure, and why might male patients have worse results than females?
  • joined the Arduino tutorial and familiarized myself with Tinkercad
  • watched videos that helped give me a visual representation of what the Fontan procedure looks like. A few easy-to-understand videos follow:
  • began reviewing papers about mock circulatory loops
    • Timms, Daniel L., et al. "A compact mock circulation loop for the in vitro testing of cardiovascular devices." Artificial organs 35.4 (2011): 384-391.; https://doi.org/10.1111/j.1525-1594.2010.01088.x
      • Key Takeaways: This study built a compact system that mimics the full heart and blood vessels to test medical devices in the lab. By including five elements, resistance, compliance, inertia, and both arterial and venous features, it closely recreates how blood moves through the body. The system can simulate many conditions, like heart failure or valve disease, just by adjusting settings like pressure and heart strength. Using a computer model beforehand helped the team design it accurately. This kind of setup gives researchers a safer, more realistic way to test heart devices before moving to animal or human trials.

Week Two: June 23 - June 27

This week I:

  • met with Dr. Cutkosky and Xinyi to check-in/monitor our progress and future work to be done
  • brainstormed keywords that are helpful when researching the Fontan procedure/single ventricle heart defects; https://docs.google.com/document/d/1PzFtSyspx8K25GiXKiMwSW97GC-OltPH3R-Ng5f5fYw/edit?tab=t.0
  • attended training to get access to the Stanford PRL
  • learned from Xinyi in the PRL as she taught Kyla and I the process to 3D print
  • joined the 2025 Summer Kickoff to the Portola Redwoods State Park! It was a great experience to get to know everyone else in BDML. We drew on posters to present our internship and summer goals, as well as went on a hike as a group
  • began a 3D print after learning from Xinyi and saw the lasering cutting process from Teo

Week One: June 16 - June 20

This week I:

  • attended a meeting with Xinyi and Dr. Cutkosky regarding her project that involves pediatric cardiac patients that undergo a Fontan procedure.
  • attended a meeting regarding a project related to robot-assisted ultrasound application examinations.
  • familiarized myself with the personal Wiki pages, as well as the Wiki pages involving various projects/lab safety; MedicalRoboticsHome
  • updated my personal Wiki page to introduce myself; Profiles.MireyaVelasquez
  • began this summer blog Wiki page.

Literature Review: To familiarize myself with the content beginning in person next week, Xinyi and Dr. Cutkosky provided some papers to read through. They are listed below:

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Page last modified on July 15, 2025, at 12:59 pm