Fig. 1:
![Tetra-polar impedance measurement scheme. From [1] by permission.](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/67971ede082aa65dea3db022/j_joeb-2025-0002_fig_001.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20251208%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251208T113619Z&X-Amz-Expires=3600&X-Amz-Signature=5f99d8cb86ce431a54edc0881369096af64febb36d841a03c9831be92f1fe1c6&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Fig. 2:
![Basic concept of FIM-6. From [2] by permission.](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/67971ede082aa65dea3db022/j_joeb-2025-0002_fig_002.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20251208%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251208T113619Z&X-Amz-Expires=3600&X-Amz-Signature=d7363ef93ed16d6fb9582fb6f0e9e4d4556e6c179dd56d6cc587753df69f2ccf&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Fig. 3:
Fig. 4:
Fig. 5:
Fig. 6:
![Circuit for the current drive section for the FIM-6 system designed in the Proteus software (Labcenter Electronics Ltd, England) [7].](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/67971ede082aa65dea3db022/j_joeb-2025-0002_fig_006.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20251208%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251208T113619Z&X-Amz-Expires=3600&X-Amz-Signature=433c5e82941924eb2c63b323193637b7d1472f6a8025663657adc0697b6c320a&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Fig. 7:
Fig. 8:
Fig. 9:
Reading for the percentage change in impedance for arrangement of FIM-6 electrodes on right and left lung during lung ventilation_ The first column shows the study region_ The second column shows the arrangement scheme of electrodes for FIM-6 configuration_ The third and fourth column shows the FZ values for breathe in and breathe out in ohms_ The last column shows the percentage change in impedance_
| Arrangement | Breathe in impedance (ohms) | Breathe out impedance (ohms) | Percentage change (Ref: breathe-out) | |
|---|---|---|---|---|
| Lower right lung | Initial | 15.35 | 12.87 | 19.27 |
| Shifting of current electrodes only | 12.38 | 9.90 | 25.05 | |
| Shifting of both current electrodes and potential electrodes | 27.23 | 21.29 | 27.90 | |
| Left lung | Back part of the left lung | 18.56 | 16.09 | 15.35 |
Reading for the percentage change in impedance for arrangement of FIM-6 electrodes on the right lung and left lung during lung ventilation_ The first column shows the arrangement scheme for the electrodes in the lung region_ The second and third column shows the FTZ values for breathe in and breathe out in ohms_ The last column shows the percentage change in impedance_
| Arrangement | Breathe in impedance (ohms) | Breathe out impedance (ohms) | Percentage change (Ref: breathe out) |
|---|---|---|---|
| Lower right lung | 29.52 | 25.32 | 16.58 |
| Lower left lung | 19.13 | 15.19 | 25.90 |
Reading for the percentage change in impedance for different separation of potential electrodes for FIM-6 during lung ventilation_ The first column shows the separation between the potential electrodes in cm_ The second and third column show the FZ values for breathe in and breathe out, respectively, in ohms_ The last column shows the percentage change in impedance with the value on breathe out as the reference_
| Separation between potential electrodes (cm) | Breathe in impedance (ohms) | Breathe-out impedance (ohms) | Percentage change (Ref: breathe out) |
|---|---|---|---|
| 10.0 | 21.30 | 18.89 | 12.76 |
| 12.5 | 28.98 | 24.63 | 17.66 |