Fig. 17

(a) Recording of LFPs. The original LFP signal, which was previously recorded from the STN in a patient with PD withdrawn from levodopa, was injected by a waveform generator (Agilent 33220A) to the inputs of the proposed instrument’s AFE, the DP-301 differential amplifier and the bioamplifier included in the Powerlab 26 T data acquisition system. (b) Amplitude spectrum of the signals presented in Fig. 17 (a). (c) The output of the proposed instrument’s AFE better tracks the changes occurring in the original LFP signal in comparison to the other two instruments. This is verified by the fact that the RMSE between the original LFP signal and the signal recorded by the proposed instrument’s AFE is less than the errors characterizing the other two instruments. (d) The detailed amplitude spectrum shows that the AFE of the proposed instrument provides accurate recording of the LFP signal, whereas the other two instruments cannot accurately record the frequencies of the LFP signal that are higher than 120 Hz