Dye Dilution; Estimate value of an Integral

Click For Summary
SUMMARY

The discussion focuses on estimating cardiac output using dye dilution, specifically with a dye concentration modeled by the function c(t)=20te^(-0.6t) over the interval [0, 10]. The known dye amount A is 6 mg, and the cardiac output is calculated using the formula F=A/∫[c(t) dt] from 0 to 10. Participants attempted to use numerical methods such as Riemann sums and Simpson's rule for integration, with one user reporting a result of 54.5916 using a Riemann sum, while another user obtained an analytical integral value around 30, leading to confusion regarding the correct estimation technique.

PREREQUISITES
  • Understanding of integral calculus, specifically numerical integration techniques.
  • Familiarity with Riemann sums and Simpson's rule for approximating integrals.
  • Knowledge of exponential decay functions and their applications in modeling.
  • Basic principles of dye dilution and its relevance in measuring cardiac output.
NEXT STEPS
  • Study the application of Simpson's rule in numerical integration for better accuracy.
  • Explore the analytical integration of functions involving exponential decay.
  • Learn about the implications of dye dilution in physiological measurements.
  • Investigate the differences between numerical and analytical methods in estimating integrals.
USEFUL FOR

Students studying calculus, particularly those focusing on numerical methods and applications in biology or medicine, as well as professionals involved in cardiac output measurement and analysis.

oddjobmj
Messages
305
Reaction score
0

Homework Statement


The dye dilution is used to measure cardiac output with 6 mg of dye. The dye concentrations, in mg/L, are modeled by c(t)=20te^(-0.6t), 0 =< t =< 10, where t is measured in seconds. Find the cardiac output.

Homework Equations


Cardiac output is given by: F=A/\int[c(t) dt]010 where the amount of dye A is known and the integral can be approximated from the concentration readings.

The Attempt at a Solution



In this case A=6 mg and c(t) = 20te^(-0.6t).

I've been trying to estimate with a Riemann sum and/or Simpson's rule but I can't figure out how to get the integral in the correct form to estimate with.

Wolfram alpha spits out 54.5916 using a Riemann sum, but the next problem in this packet (same setup with different dye amount) suggests I use Simpson's rule.

When I plug values of 0->10 into the function I get weird values but I can't integrate it without an estimation technique.
 
Physics news on Phys.org
That is pretty easy to integrate directly, isn't it? I assume you are required to integrate numerically as practice, but what do you get for the integral, analytically?

I don't get anything at all like "54..", I get around 30 for the integral and then around 0.2 for the fraction.
 

Similar threads

Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
7K
  • · Replies 2 ·
Replies
2
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
1
Views
14K
  • · Replies 7 ·
Replies
7
Views
17K
  • · Replies 0 ·
Replies
0
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
Replies
1
Views
6K
  • · Replies 1 ·
Replies
1
Views
4K