Electrosurgical generators are the devices that use high-frequency (HF) electrical currents to cut or coagulate tissue during surgery, known as electrosurgery. It consists of an electrosurgical generator that transforms electrical energy into HF current. It is operated using a specific control.
Electrosurgery is the application of a high-frequency (radio frequency) alternating polarity, electrical current to biological tissue as a means to cut, coagulate, desiccate, or fulgurate tissue. Its benefits include the ability to make precise cuts with limited blood loss. Electrosurgical devices are frequently used during surgical operations helping to prevent blood loss in hospital operating rooms or in outpatient procedures.
Electrosurgical generator units facilitate therapeutic endoscopy by supplying the high-frequency electrical current required to use many endoscopic accessories. The term electrosurgical energy describes the transformation of alternating electrical current produced by the Electrosurgical generator units into thermal energy within tissue.
High frequency Electrosurgical Generator is a surgical technique related to Diathermy, which is a clinical method that uses high frequency electromagnetic currents for clinical therapy and has surgical applications. Electrosurgery uses alternating current to directly heat the tissue itself. Unlike electrocauterization that uses direct current to heat a probe to a glowing temperature to cauterize the tissue through heat conduction.
Development of high-frequency Electrosurgical Generators
The cautery method is the basic principle of high-frequency electrosurgical treatment. Its application to disease treatment can be traced back to prehistoric times. People use heated stones to stop bleeding. In the early 1920s, surgeons used the method of cauterization and current to treat patients, and now the cautery method has become one of the most commonly applied techniques. Plant physiologist William T. Bovie is considered the father of high-frequency electrosurgical surgery.
In the 19th century, medical treatment gradually realized electronic. In 1897, Franz Nagelschmidt wrote an article on “Electrothermal Therapy” to illustrate the thermal effect discovered by d’A rsonval six years ago.
In 1900, the Parisian physician Joseph Rivered made an innovative discovery in his work. When he treated an insomnia patient with an electric current generated by a generator similar to Nagelschmidt, the spark arc between the electrodes solidified the patient’s skin, and he finally used this This arc current treated a patient with a cancerous ulcer on the hand. This is the first recorded case of a surgical operation using high-frequency current. In the following ten years, people generally used electric current to treat skin damage, oral and bladder hemangioma, hemorrhoid coagulation and other diseases.
In 1910, Clark designed and produced a new device that can generate up to 3A of current. By increasing the current and reducing the voltage, it generates a spark with greater heat and shorter time, which can penetrate deeper layers of the human body tissues.
In 1914, he used the “drying method” to describe the effects of tissue damage and carbonization due to dehydration. Clark became the first American to routinely use this method to remove malignant hyperplasia of the skin, head, neck, breast and cervix. Since then, he pioneered the American high-frequency electrosurgical technology and promoted the rapid development of this type of technology.
After cutting the tissue with the high-frequency electrosurgical knife, the cut wound is neat and without blood oozing, but it can cause local tissue blood supply obstacles, tissue cell destruction, partial tissue carbonization and fat liquefaction. At present, high-frequency electrosurgical units are widely used in departments of gynecology, stomatology, general surgery, etc., and can be used in various traditional surgical operations, including: splenectomy, thyroidectomy, liver resection, lung resection, hemorrhoid resection, gastrectomy, Nephrectomy, etc.
High-frequency electrosurgical generator uses electrodes to apply high-frequency, high-voltage current to the patient’s diseased part, cauterize the tissue, cut the diseased part or coagulate to stop bleeding, and achieve cutting (separation of body tissue) or coagulation (coagulation or interstitial fluid).
It mainly uses three physical effects: Thermal Effect, Faraday Effect and Electrolysis Effect:
Thermal Effect: the electrosurgical generator discharges, the local tissue temperature exceeds 100℃, the cell liquefaction stretches the cell membrane to achieve cutting; when the temperature is not enough to make the cell liquefaction, the cell shrinks to stop bleeding;
Faraday Effect: Human nerves and muscles are not sensitive to alternating current stimulation higher than 300 kHz;
Electrolysis Effect: The current passing through the human body makes the electrolyte in the tissue conductive, and the tissue at the two poles of the electrolyte ion is burned.
The schematic diagram of the traditional high-frequency electrosurgical generator is shown in the figure below. The energy does not pass through the cell, but only heats the outer layer of the cell, causing serious carbonization and large thermal damage.
What is a high-frequency electrosurgical generator?
Utilizing the concentrated heating effect of high-density high-frequency current on the local biological tissues, the tissues or tissue components are vaporized or burst to achieve the purpose of medical operations such as coagulation or cutting.
Features: Good effect, little damage-less bleeding
Has a bactericidal effect
Shorten the operation time and facilitate postoperative recovery
If equipped with an argon gas controller, it can also significantly improve the cutting and coagulation effect, improve the working environment, and reduce the degree of scorch.
Why use high frequency current?
Three effects of electric current passing through human tissues
- Thermal effect-high frequency electricity
- Electrochemical effect-direct current
- Faraday effect-low frequency electricity
Direct current (for example: the current produced by a battery) is not suitable.
Direct current passing through the tissue will produce an electrochemical effect, which will cause ion burns due to the accumulation of anions and cations near the electrode tissue of the high-frequency electrosurgical generator, so the high-frequency electrosurgical generator uses alternating current.
Low frequency alternating current causes:
Low frequency (50-60HZ) alternating current is not suitable for use in electrosurgery. While using this current to get the thermal effect, it also produces the Faraday effect, which will cause nerve and muscle stimulation to produce muscle contraction.
Working Principle of High-Frequency Electrosurgical Generator
Why use high frequency current?
- The stimulating effect of electric current on the body decreases as the frequency increases
When ＞100kHz, each cycle time of sinusoidal alternating current is ＜0.01ms, and the stimulation time cannot reach the threshold of excitating nerves and muscles (0.03-1ms).
When＞500 kHz, there is almost no nerve excitement. The higher the frequency, the greater the current that the human body can withstand.
- Skin collection effect, little damage to human tissues
Current density on the surface of the conductor> Current density inside the conductor,
The higher the current frequency——the higher the skin effect
The high-frequency electrosurgical generator uses the thermal effect of electric current to achieve the surgical effect of cutting and coagulation.
Why is there a thermal effect?
The high-frequency current is applied to the surgical site through the surgical electrode (scalpel head).
Since the area of the electrode touching the human body during the operation is very small, the current density under the electrode is very large, so strong heat energy is generated instantly,
These heat energy acts on the human cells, causing the tissues in the cells to evaporate explosively and the cells are destroyed, so as to achieve the surgical effects such as cutting and coagulation.
Several concepts of high-frequency electrosurgical generator
- Electric cutting:
When we use a continuous high-frequency current waveform, the current generates a lot of heat and extremely high temperature in an instant. This temperature vaporizes the cell tissue and separates the tissue. This is the effect of electrocutting.
When the output current waveform is intermittent, the instantaneous heat generation is greatly reduced, and the temperature is relatively low, which is not enough to vaporize the tissue and only produce the effect of scalding, that is, the electrocoagulation effect.
- Mixed cutting:
When the output current waveform is between electrosurgical resection and electrocoagulation, and two mixed waveforms, the surgical effect of electrosurgical surgery is a kind of simultaneous resection and coagulation.
Technical characteristics of high-frequency electrosurgical generator
1. Fast cutting speed, good hemostatic effect, simple and convenient operation;
2. Compared with traditional mechanical scalpels, the use of high-frequency electric scalpels in clinic can shorten the operation time, reduce the patient’s blood loss and blood transfusion, thereby reducing complications and surgical costs;
3. Compared with other electrosurgical instruments (such as laser knives, microwave knives, ultrasonic knives, water knives, etc.), high-frequency electrosurgical generators are suitable for a wide range of operation, easy to enter the surgical site, and easy to operate.
The Role of High-Frequency Electrosurgical Generator
- Fast cutting speed, powerful and rapid hemostasis effect. Compared with ultrasonic scalpel, it is more suitable for open surgery.
- It can greatly shorten the operation time and reduce the patient’s blood loss and blood transfusion.
- Using the skin effect of high-frequency current, it will not penetrate the human body too deeply, and the degree of damage to the human body during the operation is minimized.
Heal Force Electrosurgical Generator
EB03 electrosurgical generator is a versatile electrosurgical unit for all around surgical procedures through all types of tissue. It has integrated seven power output, tissue responding and automatic solid or split return electrode recognition functions, with which surgeons can perform highly precise and safe operations.
- EB03 electrosurgical generator comes with an easy to use interface.
- It ensures smooth cutting through all types of tissue.
- The electrosurgical generator has automatic current monitoring and program memory function.
- It offers a maximum output of 350 watts/150 watts.
- It has 6 monopolar and 1 bipolar output.
- The electrosurgical unit features isolated output, all floating.
- Adaptor for laparoscopy and thoracoscopy application is optional.
EB03 is applicable in various surgeries such as general surgery, dermatology, plastic surgery, endoscopy, vascular surgery, heart/thoracic surgery, minimally invasive surgery, neurosurgery and ophthalmology.
EB05 electrosurgical generator combines versatility and safety, for all general electrosurgical procedures such as cutting and coagulation in clinics, offices and emergency rooms.
- EB05 electrosurgical generator offers a maximum power output of 400 watts.
- 7 monopolar and 3 bipolar outputs are available.
- The electrosurgical generator ensures smooth cutting through all types of tissue.
- It realizes automatic recognition of return electrode, whether solid or spilt.
- It offers automatic current monitoring and program memory functions.
- The argon module is optional for enhanced cutting and coagulation.
- Optional adaptor for laparoscopy and thoracoscopy application.
- The electrosurgical generator has an easy to use interface.
- It features isolated output, all floating.
EB05 well combines safety and effectiveness for a broad range of electrosurgical needs, such as General surgery, Cardiology, ENT surgery, Gastroenterology, Gynaecology, Laparoscopy, Neuro surgery, Plastic surgery, Thoracic surgery and Urology.