Control of cell electroporation

An electrode unit comprising:

• an electrode configured to contact a biological cell and provide a first electrical signal to the biological cell and configured for measuring (i) a first impedance of the electrode and the biological cell measured before providing the first electrical signal to the biological cell and (ii) a second impedance of the electrode and the biological cell measured after providing the first electrical signal to the biological cell;
• a stimulation unit electrically connected to the electrode;
• an impedance measurement device configured to measure the first impedance and the second impedance of the electrode and the biological cell contacting the electrode and configured to measure a third impedance of the electrode and the biological cell after measuring the second impedance;
• and
• a comparing element configured to make a determination of whether the first impedance is greater than a first predetermined threshold and configured to produce an adjustment value based on whether an impedance drop is greater than a second predetermined threshold, wherein the impedance drop is a difference between the first impedance and the second impedance, the stimulation unit being configured to apply, via the electrode, the first electrical signal based on the determination and a second electrical signal to the biological cell based on the adjustment value and configured to update the first electrical signal for future application to another biological cell based on whether the third impedance is greater than the second impedance by more than a third predetermined threshold.