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=ASIA6AP2G7AKHQBRQUXV%2F20260320%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20260320T133316Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEGwaDGV1LWNlbnRyYWwtMSJGMEQCIEoXmSwpibts6VbJKH1X8QFZL6P2Lyjf7Z0Z3dj36CY6AiBnAXBC1UULBB%2BwymGYnEFJSGUPgU7RyFVemjvSGYA90iq8BQg1EAIaDDk2MzEzNDI4OTk0MCIMFrguYVxk2bjDcdafKpkFY3TqU2fX3l6BZ4HVoOeGAervQ%2FzfMOJu46bLheuzgn5MLzWNI9VRfKV%2FGuQq2xX838xFDIzP%2FTUUIYz008DRM5vgEtdN3fHfhN6t%2FN3ERSKROj8v%2B9HYaTMHLoY9e1hIaHALoyErt0hPoqj9qZdEWgvVB0z8dODCsh%2FQ28Oq4u8vA2iObvUxqzuK8S%2BKyHnVKNr7CUnI1eXOxY7wTNME0kiaUBc3vuTE8hQSDkmzwuazUkX74e47M%2B%2FZ%2BmuiQufUWslFbfk9Tmj4lZ4dI8bmDkgxISvhVHqTgQmKpB9jv6lIZoaEVui8poWw6VF9%2F5uSAYZ5kzq%2BYKgfqfgc91SHSHBV7iiLlJzPSwKmEjVvJczBLlMC0Zn0wXFSoM5hxcqJBiJ3%2B2VdAvd7sydkJhPTHcNik72IOk4I7vyOzT%2B5l3IVFk4KRxnpf%2BDjKnv6a%2FBjz19GILAwa2VFW4BcV9LUwub3eXfOGUguynFn%2FwjMdaOkk9N61o7H0Vsif1NAR9flGG1bdcimxASoGYW40xjyciDqVXytF6oIyqvDuUCSDf6%2FsA8%2BALJkjWJ7oNkbG%2FtVjIA1bs4kgpgfsrJl7FUvufWU0wD8t4kA2P70ly0h5LhxnHpSX5mf8wgaLWwKrtwdajXXnkiUnwx4E5nUIvc9UnQqUNb1S9P0EPfPMcKlKnxN1kbjMeBT9LeJuxVzDSVH0ii4VHMFtCkTabPE0iaTCZQKTH2imNwUPgSySHuiT02Nd7Wns8vTE91LxIXKwpD4p6EjAz30B7kcNkMZQ0zFMkVcAgsrRiMHez%2FZSqgkdjZZEJKsXlxxFJuMPCNJIhYeAhKTky6wxmeY3c2YHYYUXptOg3OQ67TYEjFaRh5SnRoaaBP%2BioXgFP4w4O%2F0zQY6sgG3UFhtLyPLmjDewdqinkbr9bUk%2BwN%2F1PHOTPBKUpmebw%2B8UupMYiJT26irvewTzK27RrUaWXAkKN3w12E6BRKpMjhd0lCW8oIMwSBzDybNP9sefUnR6oHSsyKTML5oFX8FiEf%2FixkZmBRGBZMgjLkISr13UM7HZVPvIjA%2FguTU8GN4DMOM1%2BSgQrKVnKQF6ozdiuBUi8DP556gU72bFwC1XOEbrobtthzC6vBWkCJrgm3Q&X-Amz-Signature=f83504cdc19708597815f4361ff3252c170f97426f48672d1b0cc2f5238abab0&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=ASIA6AP2G7AKHQBRQUXV%2F20260320%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20260320T133316Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEGwaDGV1LWNlbnRyYWwtMSJGMEQCIEoXmSwpibts6VbJKH1X8QFZL6P2Lyjf7Z0Z3dj36CY6AiBnAXBC1UULBB%2BwymGYnEFJSGUPgU7RyFVemjvSGYA90iq8BQg1EAIaDDk2MzEzNDI4OTk0MCIMFrguYVxk2bjDcdafKpkFY3TqU2fX3l6BZ4HVoOeGAervQ%2FzfMOJu46bLheuzgn5MLzWNI9VRfKV%2FGuQq2xX838xFDIzP%2FTUUIYz008DRM5vgEtdN3fHfhN6t%2FN3ERSKROj8v%2B9HYaTMHLoY9e1hIaHALoyErt0hPoqj9qZdEWgvVB0z8dODCsh%2FQ28Oq4u8vA2iObvUxqzuK8S%2BKyHnVKNr7CUnI1eXOxY7wTNME0kiaUBc3vuTE8hQSDkmzwuazUkX74e47M%2B%2FZ%2BmuiQufUWslFbfk9Tmj4lZ4dI8bmDkgxISvhVHqTgQmKpB9jv6lIZoaEVui8poWw6VF9%2F5uSAYZ5kzq%2BYKgfqfgc91SHSHBV7iiLlJzPSwKmEjVvJczBLlMC0Zn0wXFSoM5hxcqJBiJ3%2B2VdAvd7sydkJhPTHcNik72IOk4I7vyOzT%2B5l3IVFk4KRxnpf%2BDjKnv6a%2FBjz19GILAwa2VFW4BcV9LUwub3eXfOGUguynFn%2FwjMdaOkk9N61o7H0Vsif1NAR9flGG1bdcimxASoGYW40xjyciDqVXytF6oIyqvDuUCSDf6%2FsA8%2BALJkjWJ7oNkbG%2FtVjIA1bs4kgpgfsrJl7FUvufWU0wD8t4kA2P70ly0h5LhxnHpSX5mf8wgaLWwKrtwdajXXnkiUnwx4E5nUIvc9UnQqUNb1S9P0EPfPMcKlKnxN1kbjMeBT9LeJuxVzDSVH0ii4VHMFtCkTabPE0iaTCZQKTH2imNwUPgSySHuiT02Nd7Wns8vTE91LxIXKwpD4p6EjAz30B7kcNkMZQ0zFMkVcAgsrRiMHez%2FZSqgkdjZZEJKsXlxxFJuMPCNJIhYeAhKTky6wxmeY3c2YHYYUXptOg3OQ67TYEjFaRh5SnRoaaBP%2BioXgFP4w4O%2F0zQY6sgG3UFhtLyPLmjDewdqinkbr9bUk%2BwN%2F1PHOTPBKUpmebw%2B8UupMYiJT26irvewTzK27RrUaWXAkKN3w12E6BRKpMjhd0lCW8oIMwSBzDybNP9sefUnR6oHSsyKTML5oFX8FiEf%2FixkZmBRGBZMgjLkISr13UM7HZVPvIjA%2FguTU8GN4DMOM1%2BSgQrKVnKQF6ozdiuBUi8DP556gU72bFwC1XOEbrobtthzC6vBWkCJrgm3Q&X-Amz-Signature=309b8dbc9a00bdd7fd4714e9005012e8d252d04071a436526435aa605c65b6e9&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=ASIA6AP2G7AKHQBRQUXV%2F20260320%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20260320T133316Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEGwaDGV1LWNlbnRyYWwtMSJGMEQCIEoXmSwpibts6VbJKH1X8QFZL6P2Lyjf7Z0Z3dj36CY6AiBnAXBC1UULBB%2BwymGYnEFJSGUPgU7RyFVemjvSGYA90iq8BQg1EAIaDDk2MzEzNDI4OTk0MCIMFrguYVxk2bjDcdafKpkFY3TqU2fX3l6BZ4HVoOeGAervQ%2FzfMOJu46bLheuzgn5MLzWNI9VRfKV%2FGuQq2xX838xFDIzP%2FTUUIYz008DRM5vgEtdN3fHfhN6t%2FN3ERSKROj8v%2B9HYaTMHLoY9e1hIaHALoyErt0hPoqj9qZdEWgvVB0z8dODCsh%2FQ28Oq4u8vA2iObvUxqzuK8S%2BKyHnVKNr7CUnI1eXOxY7wTNME0kiaUBc3vuTE8hQSDkmzwuazUkX74e47M%2B%2FZ%2BmuiQufUWslFbfk9Tmj4lZ4dI8bmDkgxISvhVHqTgQmKpB9jv6lIZoaEVui8poWw6VF9%2F5uSAYZ5kzq%2BYKgfqfgc91SHSHBV7iiLlJzPSwKmEjVvJczBLlMC0Zn0wXFSoM5hxcqJBiJ3%2B2VdAvd7sydkJhPTHcNik72IOk4I7vyOzT%2B5l3IVFk4KRxnpf%2BDjKnv6a%2FBjz19GILAwa2VFW4BcV9LUwub3eXfOGUguynFn%2FwjMdaOkk9N61o7H0Vsif1NAR9flGG1bdcimxASoGYW40xjyciDqVXytF6oIyqvDuUCSDf6%2FsA8%2BALJkjWJ7oNkbG%2FtVjIA1bs4kgpgfsrJl7FUvufWU0wD8t4kA2P70ly0h5LhxnHpSX5mf8wgaLWwKrtwdajXXnkiUnwx4E5nUIvc9UnQqUNb1S9P0EPfPMcKlKnxN1kbjMeBT9LeJuxVzDSVH0ii4VHMFtCkTabPE0iaTCZQKTH2imNwUPgSySHuiT02Nd7Wns8vTE91LxIXKwpD4p6EjAz30B7kcNkMZQ0zFMkVcAgsrRiMHez%2FZSqgkdjZZEJKsXlxxFJuMPCNJIhYeAhKTky6wxmeY3c2YHYYUXptOg3OQ67TYEjFaRh5SnRoaaBP%2BioXgFP4w4O%2F0zQY6sgG3UFhtLyPLmjDewdqinkbr9bUk%2BwN%2F1PHOTPBKUpmebw%2B8UupMYiJT26irvewTzK27RrUaWXAkKN3w12E6BRKpMjhd0lCW8oIMwSBzDybNP9sefUnR6oHSsyKTML5oFX8FiEf%2FixkZmBRGBZMgjLkISr13UM7HZVPvIjA%2FguTU8GN4DMOM1%2BSgQrKVnKQF6ozdiuBUi8DP556gU72bFwC1XOEbrobtthzC6vBWkCJrgm3Q&X-Amz-Signature=5d336273868b2732affb755857dc95c375c696bcda849ac8685c274feb9480ab&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 |