Draw the key components of a biomedical processing system. The DSP system must be able to connect to a pulse-rate sensor signal source, process the data digitally and then be able to send these signals wirelessly using a Bluetooth RF interface to a remote PC. The biomedical system in Q2a(i) can process a 1 V signal from the sensor signal to a 1 V full-scale ADC with an SQNR of 74 dB. The sampling frequency of the system is set at 250 Hz. Although, a low-pass anti-allas Butterworth filter with a cut-off frequency of 40 Hz is used to limit higher frequencies, it is observed that an unwanted signal of amplitude 0.5 V at a frequency of 160 Hz is appearing at the input to filter. Calculate the order of the low-pass Butterworth anti-alias filter required such that the unwanted signal (@160 Hz) does not degrade the specifications of the overall system.