The Caffeinated Brain BMES 546 December 11 th, 2014 Julia Orchinik Alex Vogel Mike Yoder

Caffeine Background  Bitter substance found in coffee, tea, soft drinks, chocolate, certain medicines and energy drinks  Affects body’s metabolism – stimulates the central nervous system  Increases alertness, but can also induce unwanted side-effects of anxiety, nausea, and caffeine withdrawal headaches  68% of the coffee drinkers in the U.S. feel the need to drink a cup of coffee within the first hour of waking up.

Caffeine Effectiveness Caffeine binds to adenosine receptors in the brain  Adenosine - natural sedative  Caffeine inhibits adenosine binding  no feeling “sleepy”  Takes 30 minutes for caffeine to be absorbed into blood  Hour for caffeinated blood to reach brain Pregnancy & Use of Oral Contraceptives(birth control pill)  Doubles half-life of caffeine in the body Cigarette Smoking  Average half-life elimination of caffeine in the body is 70% of the half-life for non-smokers

Problem The half-life of caffeine in the brain is influenced by many factors.  How does the concentration of caffeine in the brain vary with beverage choice and physiological factors, specifically weight, smoking cigarettes, pregnancy, and use of oral contraceptives?  How do multiple beverages consumed throughout the day affect caffeine concentration in the brain?

Caffeine GUI Demonstration

Data and Diff. Equations  A = A o e -ln(2) * t / H1/2 (caffeine exponential decay)  Drink Type, A o = chosen once or twice as a “ value ”  H 1/2 = C(280-W)/26 (half life equation with weight)  Conditions, C = indexed as “ strings ” to return a number  If two conditions, took the product as the condition rate  dB/dt = -k 1 B+k 2 A used to calculate B = “concentrations”

Results and Conclusions The half-life of caffeine determines how long caffeine remains in the body.  If the half-life increases, caffeine is eliminated from the body faster. (Pregnancy, Oral Contraceptives)  If the half-life decreases, caffeine remains in the body longer. (Smoking cigarettes)  Combinations of factors (i.e. smoking and use of oral contraceptives) results in a cumulative caffeine half-life.

Challenges and Modifications  Trouble adding a second beverage without changing first beverage selection  Ignored “gender ” – No generalized gender equations  Hard to produce a generalized model of caffeine in the brain since caffeine half life rates can change due to other physiological factors (age, sleep, stress, tolerance)  More beverage choices and caffeinated foods  Chocolate has caffeine but caffeine is absorbed slower when digested; GUI works for fluids.

References   Borelli, Robert L. and Courtney S. Coleman. Differential Equations: a Modeling Perspective.  Debry, Gerard. Coffee and Health. Paris: John Libbey Eurotext,    Nawrot, S et all. Effects of Caffeine on Human Health Toxicological Evaluation Section, Chemical Health Hazard Assessment Division, Bureau of Chemical Safety, Food Directorate, Health Canada, Tunney’s Pasture, PL 2204D1, Ottawa, Ontario,Canada K1A 0L2 18 June 2012

Who Did What?  Julia  GUI Design  Flow Chart Process for Callbacks  Report  Alex  Function coding for Caffeine.m and Caffeinegui.m  Differential Equation Derivations  Mike  Research for conditions and drink types  Function coding for Caffeine.m and GUI modifications  User Guide and PP