1. The Effect of Caffeine on Neurological Dopamine Production Process Dynamics & Control October 13 th, 2004 Student Name 1 Student Name 2

2. Presentation Outline Introduction Simulation Assumptions Process Outcomes  Laplace via Maple  Matlab  Simulink Conclusion

3. What is Caffeine? The most commonly used neurological drug worldwide trimethylxanthine, (C 8 H 10 N 4 O 2 ) bitter tasting white powder Retrieved from: www.cs.virginia.edu/.../ caffeine-molecule.gif

4. Common Substances Coffee, tea, soft drinks, and pain medication Caffeine Content:  Brewed coffee: 40-180 mg  Black Tea: 20-100 mg  Excedrin: 65 mg  Mountain Dew: 55 mg  Green Tea: 8-36 mg

5. What is Dopamine? Neurotransmitter  Movement  Thought processes  Emotions  Pleasure “Rewards” centers of the brain Retrieved from: http://www.bip.bham.ac.uk/osmart/msctox/

6. The Relationship Between Caffeine and Dopamine Caffeine has ½ life of ~6 hours in a healthy person Enters Digestive tract  Some caffeine is lost in liver  Remainder enters bloodstream Caffeine enters the brain  Stimulates excessive dopamine release  Blocks uptake receptors

7. Ultimate Response:

8. Simulation Assumptions Body consists of 3 tanks  Stomach, Liver, and Brain Flow rates, tank volumes and density remain constant Dopamine production is a first order chemical reaction  Caffeine→Dopamine

9. Initial Conditions F1F1 25 dL/s F2F2 20 dL/s F3F3 0.0001 dL/s F4F4 F5F5 0.05 dL/s k1k1 0.250 mol-dL -1 s -1 k2k2 0.125 mol-dL -1 s -1 VsVs 5 dL VlVl 4 dL VbVb 2 dL

10. Simulation Process C i,caf., F 1 Stomach: C 1, V s F 2, C 1 C 3, F 3, D 3 Liver: D 2, C 2, V l Brain: D 5, C 5, V b F 4, C 4, D 4 F 5, D 5 Caffeine Dopamine r b =k 1 C 5

11. Focus Amount of Dopamine produced as a function of input Caffeine

12. Mass Balances: Stomach C i,caf., F 1 Stomach: C 1, V s F 2, C 1 Equation 1. Stomach Mass Balance (Caffeine)

13. Mass Balance: Liver F 2, C 1 C 3, F 3, D 3 Liver: D 2, C 2, V l F 4, C 4, D 4 F 5, D 5 Equation 2. Liver Mass Balance (Caffeine) Equation 3. Liver Mass Balance (Dopamine)

14. Mass Balance: Brain Brain: D 5, C 5, V b F 4, C 4, D 4 F 5, D 5 Caffeine Dopamine r b =k 1 C 5 Equation 4. Brain Mass Balance (Caffeine) Equation 5. Brain Mass Balance (Dopamine)

15. Laplace Transform: Steady State S-Domain t-Domain =C i,caf { }

16. Caffeine Impulse Function

17. Caffeine Unit Step Function

18. Caffeine at Steady-State

19. Dopamine at Steady State

20. Dopamine Unit Step Function

21. Dopamine Impulse Function

22. Simulink Unit Step Function For Caffeine

23. Simulink Unit Step Function For Dopamine

24. Simulink Impulse Function for Caffeine

25. Simulink Impulse Function for Dopamine

26. Conclusion Achieved anticipated results in the theoretical process Possible differences in real process Suggestions Thanks to Dr. Rodgers

27. Questions?