Algorithm 2 Estimation of the RR from the $O_{2}Hb$ signal’s baseline wander
Input:$O_{2}HB$ signal $x\left(n\right)$, Troughs of $O_{2}HB$ signal K, and the length of moving average
	filter L
Output:$RR$
1:	$m\left(n\right)\leftarrow$ Spline (K, $x\left(K\right)$, 1 to length($x\left(n\right)$))
2:	$MA\leftarrow$$\frac{1}{L}\times$ ones(L,1)
3:	$S\left(n\right)\leftarrow$ filtfilt($MA$,1,$m\left(n\right)$)
4:	$G\left(n\right)\leftarrow$$m\left(n\right)-S\left(n\right)$
5:	$[P,F]\leftarrow$ FFT ($G\left(n\right)$)
6:	$r\leftarrow$ find($P\left(F\right)\leftarrow$ Max($P\left(F\right)$))
7:	$RR\leftarrow$ r × 60
8:	return  $RR$