Hi, this is not implemented in HRVTool. Giving a reasonable recording length, it should be doable by using the R amplitude modulation, e.g. see DOI 10.1088/1361-6579/aa670e. You are welcome to contribute any code making this possible.
You can export the inter-beat-intervals using the button 'Save annotations' in the top panel on the right. It saves all peak locations as mat, EDF, txt or csv files to allow the externaö use (out of the toolbox). I recommend saving the intervals and then plotting e.g. with the help of the function provided in the class HRV.m, e.g. plotting the first 20 relative intervals: HRV.rrx_view(RR, 1, 1:20)
RR intervals in HRVTool 1.07 are internally stored in milliseconds. The spectrum displayed in the app is computed by the fft function of Matlab (see de.mathworks.com/help/matlab/ref/fft.html) applied to the RR tachogram. As FFT requires an equidistant input vector, the RR tachogram will be interpolated with 'interp1'. If the type of interpolation is not set, it uses spline interpolation as default option. Within 'fft' I use a z-score normalized input of the spline-interpolated RR tachogram, which is then without any unit: Y = fft(HRV.nanzscore(RR_rsmp),NFFT)/L; The resulting single-sided amplitude spectrum should then have no unit at all, but still making it possible to compute normalized measures pULF,pLF, pHF.
hello Marcus, is it possible to extrapolate breathing rate using this package?
Hi, this is not implemented in HRVTool. Giving a reasonable recording length, it should be doable by using the R amplitude modulation, e.g. see DOI 10.1088/1361-6579/aa670e. You are welcome to contribute any code making this possible.
hi marcus, could you let me know how can i extract rr-tachogram dato to exel or txt file?
You can export the inter-beat-intervals using the button 'Save annotations' in the top panel on the right. It saves all peak locations as mat, EDF, txt or csv files to allow the externaö use (out of the toolbox). I recommend saving the intervals and then plotting e.g. with the help of the function provided in the class HRV.m, e.g. plotting the first 20 relative intervals:
HRV.rrx_view(RR, 1, 1:20)
hi marcus, thank you for the video. could you let me know the Y-axis unit of the 'Spectrum of the RR Tachogram'?
RR intervals in HRVTool 1.07 are internally stored in milliseconds. The spectrum displayed in the app is computed by the fft function of Matlab (see de.mathworks.com/help/matlab/ref/fft.html) applied to the RR tachogram. As FFT requires an equidistant input vector, the RR tachogram will be interpolated with 'interp1'. If the type of interpolation is not set, it uses spline interpolation as default option. Within 'fft' I use a z-score normalized input of the spline-interpolated RR tachogram, which is then without any unit: Y = fft(HRV.nanzscore(RR_rsmp),NFFT)/L; The resulting single-sided amplitude spectrum should then have no unit at all, but still making it possible to compute normalized measures pULF,pLF, pHF.