Forum: help

RE: How to obtain Porges amplitude of RSA Value [ Reply ] By: samar singh on 2017-08-17 18:00	[forum:45263]
Hi Constantino Thanks for that. Extremely helpful. RHRV is a great gift but this forum has been really valuable. Much appreciated. best regards samar

RE: How to obtain Porges amplitude of RSA Value [ Reply ]
By: Constantino Antonio on 2017-08-17 15:58

[forum:45262]

Hi,

If I understood correctly, steps 1) and 2) can be done with RHRV by reading and interpolating the HRV data (LoadBeatXXX and InterpolateNIHR functions). The resulting time series can be obtained under the HRVData$HR field.

For step 3) I suggest to use the rollapply function of the zoo package (apply a function in temporal windows) in combination with the spline function (cubic interpolation) over the previously calculated HRVData$HR data.

Finally, the package 'signal' provides functions for performing the frequency-filtering.

Hope this helps you,
Kind regards

How to obtain Porges amplitude of RSA Value [ Reply ]
By: samar singh on 2017-08-11 05:59

[forum:45258]

How would I implement the following process in RHRV especially steps 3 and 4
The method includes the following steps:
1) R-R intervals are timed to the nearest ms to produce a time series of sequential heart periods; 2) sequential heart periods are resampled into 250 ms intervals to produce time-based data;
3) the time-based series is detrended by a 51-point cubic moving polynomial (Porges &
Bohrer, 1990) that is stepped through the data to create a smoothed template and the
template is subtracted from the original time-based series to generate a detrended residual
series;
4) the detrended time series is bandpassed to extract the variance in the heart period
pattern associated with spontaneous breathing (0.12–1.0 Hz to account for the wide range of
ages in the study cohort); and
5) the natural logarithm of the variance of the bandpassed time series is calculated as the measure of the amplitude of RSA