Geometric HRV indices (triangular index and TINN)

Computes the geometric heart-rate-variability measures defined by the Task Force (1996) from a series of NN (normal-to-normal) intervals: the HRV triangular index and the triangular interpolation of the NN interval histogram (TINN).

Usage

ecgHRVgeometric(rr, bin_ms = 7.8125)

Arguments

rr: Numeric vector of NN/RR intervals in milliseconds.
bin_ms: Histogram bin width in milliseconds. Defaults to 7.8125 ms (1/128 s), the Task Force standard.

Value

A list with:

HRV_triangular_index: Total number of NN intervals divided by the height (modal count) of the NN histogram.
TINN: Baseline width, in milliseconds, of the triangle that best approximates the NN histogram in a least-squares sense.

References

Task Force of the ESC and NASPE (1996). Heart rate variability: standards of measurement. Circulation, 93(5), 1043-1065.

Examples

set.seed(1)
rr <- 800 + rnorm(500, sd = 40)  # NN intervals in ms
ecgHRVgeometric(rr)
#> $HRV_triangular_index
#> [1] 9.803922
#> 
#> $TINN
#> [1] 156.25
#>