Choice of power supply block for RPI4 PCB and sensors
EMG sensors : Single Supply +2.9V to +5.7V   (low current)
FSR &amp; ADS1299's Unipolar or Bipolar Supplies: Analog: 4.75 ~ 5.25 V Digital: 1.8 ~ 3.6 V
&quot;I need to power them with the bipolar mode +2.5V/-2.5V.&quot;
Not really. Can you choose 5V=Vref and Vref/2 as your DC and AC ground reference ?
; or some ratio like this with DC bias to Vref/2.  &quot;ground&quot; =  &quot;relative&quot; 0V.
For EMG and FSR with long wires, you also want medically rated isolation from grid and SMPS noise, so battery power is best with such as 5V Power Bank with 3.3V LDO for Digital.
Always be conservative for Wh capacity for rPi then enjoy longer debug hours. ;)
Using charger at the same time would result in serious S/N degradation and even with shielded twisted pairs everywhere with large CM Chokes. (Consider Cat 6 cable with connectors and ground shields in use)

10nF RF Cap to AC ground helps reduce RF noise from 3.6 to 5V SMPS converter noise and ,

may need special attention to layout, ground, minimize crosstalk and muscle galvanic skin response,  CM chokes , minimize
wire loop area, antenna effects, use quality electrode pads and/or with right leg drive, RLD to cancel CM noise.



rPi 4 power specs
https://raspi.tv/2019/how-much-power-does-the-pi4b-use-power-measurements