t50_maes_ghoos {breathtestcore} R Documentation

## Half-emptying time by Maes/Ghoos method

### Description

Half-emptying time t50 as determined from the fit of a beta exponential function. In the Maes/Ghoos model, it is defined as the time when the area under curve (AUC) is 50% of the AUC from 0 to infinity.

Maes B D, Ghoos Y F, Rutgeerts P J, Hiele M I, Geypens B and Vantrappen G 1994 Dig. Dis. Sci. 39 S104-6.

### Usage

```t50_maes_ghoos(cf)
```

### Arguments

 `cf` named vector of coefficients; only `k` and `beta` are required note that `k` is measured in 1/min (e.g. 0.01/min), usually it is quoted as 1/h (e.g. 0.6/h).

### Value

Time in minutes when area under curve is 50% of the AUC to infinity. In the Maes/Ghoos model, this is used as a surrogate for gastric emptying half time `t50`.

`exp_beta`, and `t50_bluck_coward` for an example.

### Examples

```# Integral from 0 to infinity is 100 at dose 100 mg
integrate(exp_beta, 0, Inf, beta = 1.5, k = 0.01, m = 1, dose = 100)
t50_mg = t50_maes_ghoos(c(beta = 1.5, k = 0.01, dose = 100))
t50_mg
# Integral to half-emptying time \code{t50_maes_ghoos} is 50
integrate(exp_beta, 0, t50_mg, beta = 1.5, k = 0.01, m = 1, dose = 100)
```

[Package breathtestcore version 0.8.1 Index]