Table 5.
Comparison of the proposed instrument with other state-of-the-art wearable and wireless biopotential acquisition systems existing in the literature
| Parameters | [43] | [44] | [45] | This work |
|---|---|---|---|---|
| Number of channels | 32 | 8 | 4 | 5 (+ 3) |
| Type of biosignals | EMG | ECG, EMG | EEG, LFP | ExG, ECoG, LFP, ERNA, body position and movement, PV ectopic activity (+ amperometric/potentiometric) |
| Voltage gain | 46 dB | ≈ 28 dB (max) | ≈ 54 dB | 60 dB |
| Input voltage range | ±5 mV | ±100 mV | ±1.15 mV | ±2.3 mV |
| Maximum available bandwidth | 10–500 Hz | 0–250 Hz | 1.5–100 Hz | 0.5–500 Hz |
| Input impedance | 1.3 GΩ (10 Hz) | ≈ 620 MΩ (10 Hz) | 47 kΩ (10 Hz) | ≈ 8 GΩ (10 Hz) |
| Input referred noise | < 3 μV rms | 0.2 μV rms (0–250 Hz) | ≈ 0.606 μV rms (1.5–100 Hz) | 0.169 μV rms (0.5–500 Hz) |
| CMRR | 82 dB | 110 dB | – | 134 dB |
| Maximum resolution of the ADC | 16 bits | 24 bits | 16 bits | 24 bits |
| Maximum sampling frequency | 2048 SPS | 500 SPS (16 kSPS for wired) | 500 SPS | 1 kSPS (32 kSPS for wired) |
| Hours of continuous operation | 5 (600 mAh 1-Cell LiPo battery) | 13.6 (1700 mAh battery) | 6 to 8 (CR1/3 N lithium ion button-cell battery) | 8 (1 Ah lithium battery) |
| Wireless capability | Yes (Wi-Fi) | Yes (Bluetooth) | Yes (2.4 GHz MSK) | Yes (Zigbee) |
| Latency | 12 ms | – | – | 1 ms |
| Max. transmission range | 22 m | 10 m | 3–5 m | 5 m |
| Area (length × width) | 10.2 cm2 | 21.7 cm2 (PCB area) | 4.76 cm2 | 44 cm2 (PCB area) |