Why your blood should flow like ketchup | Sean Farrington, PhD | TEDxWilmington

Key Concepts:

• Rheology: The study of flow and deformation of materials, particularly those that are neither purely solid nor purely liquid.
• Viscosity: A measure of a fluid's resistance to flow (thickness).
• Non-Newtonian Fluids: Fluids whose viscosity changes under applied force (shear). Examples include ketchup, blood, and some peanut butter and shampoo formulations.
• Shear-Thinning Fluid: A fluid whose viscosity decreases under shear stress (e.g., blood).
• Cardiovascular Disease: Diseases affecting the heart or blood vessels.
• Coronary Atherosclerosis: A chronic condition where plaque builds up in the arteries, narrowing them and reducing blood flow.
• Microfluidic Chip: A miniaturized device used to manipulate small amounts of fluids, often for diagnostic purposes.

1. Introduction and Personal Anecdote:

• The speaker recounts how his uncle's stories about his aerospace engineering career, including working on an Apollo rocket, inspired him to become an engineer.
• He emphasizes that engineering involves not only building amazing things but also a vital responsibility, sometimes with the ability to save human lives.
• He mentions his PhD advisor warning him about the consequences of engineering mistakes.

2. Rheology Explained:

• The speaker's PhD is in the field of rheology, which he initially didn't expect.
• Rheology is defined as the study of the flow and deformation of materials, primarily to measure viscosity for intended function.
• It's most useful for materials that are neither liquid nor solid.
• Examples of rheology in everyday products: lotion, motor oil, cement.

3. Rheology Lab Demonstrations:

• Peanut Butter: Different peanut butter consistencies (sticking to bread vs. sliding off) illustrate varying rheological properties.
• Shampoo: Shampoo should maintain its shape in the hand. Diluting shampoo with water changes its rheological properties, ruining its function.
• Ketchup: Different ketchup brands have different textures. An experiment is conducted by flipping beakers of different ketchup brands to demonstrate the difference in flow rate. One ketchup is clearly thicker and drains slower.

4. Non-Newtonian Fluids and Product Manufacturing:

• The demonstrated materials (peanut butter, shampoo, ketchup) are classified as non-Newtonian fluids.
• Rheology is used to measure the flow properties of these materials to ensure reproducible manufacturing and desired texture.

5. Rheology in Medical Diagnostics: Blood Viscosity:

• The speaker's primary interest lies in the application of rheology in medical diagnostics, specifically blood rheology.
• Blood is a non-Newtonian, shear-thinning fluid, which is essential for healthy blood flow.
• High blood viscosity increases the risk of clots or aneurysms, while low viscosity can lead to inflammation.
• Measuring blood viscosity could provide a method for early detection of cardiovascular disease.

6. The Problem: Lack of Awareness and Implementation:

• Rheology is a niche field, largely unknown to the public, hindering its widespread use in medical diagnostics.
• Statistics: Up to 46% of people over 40 have some form of coronary atherosclerosis. One quarter of deaths in the United States are caused by heart disease.
• Early detection of cardiovascular disease is crucial for effective treatment.
• Blood pressure monitoring has been used for 300 years. Blood rheology is at a similar stage of potential but lacks awareness.

7. The Solution: Collaboration and Awareness:

• Physicians and engineers need to collaborate to implement blood rheology in practice.
• The speaker's work involves developing a microfluidic chip to simplify rheological measurements.
• The goal is to create a small, cheap, portable device to measure blood viscosity, replacing expensive, bulky equipment.
• Some physicians are already using blood rheology with positive results.

8. Call to Action:

• The speaker urges the audience to spread awareness about blood rheology.
• He encourages those in the medical community to explore the science and consider its applications.
• He emphasizes the potential of blood rheology to improve cardiovascular disease diagnosis and save lives.

9. Conclusion:

• Increased awareness of blood rheology can lead to better solutions for pressing medical issues.
• Spreading awareness can potentially save lives.