Electrosurgical unit

Glossary

Frequency: The frequency is an magnitude that allow maesure the amount of repetitions that an event can occur.

Power: The power is the rate that energy is consumed.

Electrode: An electrode is an electrical conductor that allow connect a non metallic surface with the circuit.

Electrosurgical Unit (ESU)

The electrosurgical unit is an equipment that allow cut the skin in surgical procesures, besides cauterize the blood vessels. The electrosurgical unit work with current in high frequencies, allowing dont tamage the nervous system. ESU have different kind of waves to make the cuts, for example, to do coagulation, it has sused the damped sin wave, because allow deal more damage to the tissue. To make cuts in the tissue it has used the normal sine wave, because allow focus the energy over the tissue and start tu cut with lower coagulation an tissue damage.

Image 1. Electrosurgical unit model.

Circuit design

Image 2. R2R cirtuit to convert digital to analog signal.

This circuit let convert the analogic signals of Labview or Arduino to analogic signals that it can be read and visualized in osciloscope and work with analogic electronic (amplifiers, filters, etc.)

Image3. Power circuit to bisturi.

The power circuit is get the analogic signal and with TIP switch the signal when the cut or coagulation mode is selected, so in our result we didn´t get the power necessary to really cut or do coagulation, in this case it were necessary desing a power stage with hibrid model.

Image4. Amplitude modulated to generate wave to cut in electrosurgical unit.

Image 5. Wave to coagulation mode

 In image 4 and 5 we created the waves to electrosurgical unit based on amplitude and frecuency modulated that are the similar behavior that waves used in cut mode and coagulation mode respectively.

So in the next images you can see working the electrosurgical unit with the pencil, the return electrode and the patient (ham) in every mode.

Image 6. Electrosurgical unit working y coagulation mode.

Image 7. Electrosurgical unit working in cut mode

Finally in the next video there is a working mode of device with visualization and workiing in ham.