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Jehangir Medical, founded in 1971, holds the credit of being "The First Indian Manufacturer Of Electrosurgical Equipment". The company has been manufacturing state-of-art new generation equipments & accessories since last 35 years. The company continues to provide solutions to many challenging surgical problems through consistent research & product development.
Introduction to Electrosurgery
History :
In the earlier days of medical science, before the advent of electricity heated surgical implements were used for very restricted operative convenience. Today, with the present advancement in electronics the same basic principles have been exploited & used for a greater variety of surgical results namely-cutting, coagulating & desiccating.
Electrosurgery (ES) :
Modern electro surgery can be interpreted as the use of a radio frequency (RF) current to achieve the desired surgical effects. Below 100 kHz (kilocycles per seconds) of electrical current, it is observed that muscle & nerve stimulation occurs. Hence, frequencies sufficiently above 100 kHz are invariably used in ES procedure. Earlier ES generators used up to 4000 kHz current where reactive effects due to stray inductance & stray capacitance produced undesired leakage paths. New generation solid state electronics ES generators operate around 500 kHz RF current as a compromise to confine the useful output to working electrodes & at the same time avoiding muscle stimulation.
Principal Surgical Effects :
There are two principal surgical effects that can be produce in ES procedure.
They are :
a) CUT
b) COAGULATION
Procedure Classification :
Modern ES procedures can be classified into two categories.

A) MONOPOLAR Mode :
Monopolar procedures are those ES procedures that need to use of a patient plate (PP) for the current path. Modern ES generators provide a two wire floating output circuit. Following figure shows a symbolic arrangement for understanding.
Since the area of active electrode is very small compared to that of PP, the concentration of current (i.e. current per unit area) is very large in the immediate vicinity of the actual electrode. When this exceeds a threshold value within the tissues ES effects will occur.
Hence, fine needle lancet or fine wire loop active electrodes achieve a larger current density & produce dominant effects locally whether cutting or fulgurating. On the other hand large surface area electrodes cause lesser current density in the tissue but extending over larger zone. Note that the current density in the tissues immediately in contact with PP is minimum over the entire zone compared to anywhere else. The current density near the PP in the tissues is well below the threshold of producing any ES effects. This makes one very important point clear that the entire surface area of PP must be in very good electrical contact with the tissues to avoid ES effects at PP. Contrary to this, spot contacts over the area can raise the local current density in the nearby tissues & can cause burns. Suitable gels should be used to improve the electrical contact with the tissues.
The PP must be affixed as near as possible to the operating area. The current path should be as short as possible & in longitudinal or diagonal direction of the body & not transverse at especially the thorax.
Also bony areas are to be avoided as they cause multiple discrete contact areas. No part of the patients body should come in contact with other metal parts or earthed & conducting parts (e.g. operating table, attachment, wet padding, moist clothes) so that RF leakages are avoided from any undesired points.
A.1) CUT : If by some means the tissue temperature is made to exceed 100C in a very short time, the cell fluid will vapourise. The cells in the tissue will explode & split up due to vapour pressure & cause tissue separation resultitng in what is called cutting the tissue. The heating action is so rapid that the heat generated has little ime available to conduct to the adjacent tissue. With electrode movement, an incision is formed. As the RF voltage is sufficiently high, a spark will jump across to the adjacent moist tissue & thus ionizing the air, Major heating energy is concentrated in this spark & the cutting progresses as the electrodes is moved along. This clarifies one thing that desiccation (i.e. removing moisture) alone can not result in a cutting effect.
A typical waveform of cutting current is shown in following figure & in electrical terminology is called a continuous sine waveform occurring at the operating RF.

A.1.1) BLEND Mode : Blend signifies a mixture of the cutting and coagulation modes. Under this mode, one gets the advantage of Homeostasis during cutting. It should therefore be regarded as a sub mode of cutting i.e. Pure cutting effect with three other selected BLEND modes for superior blending options. Following figure shows the typical current waveform for this mode.

A.2) COAGULATION :
Coagulation is the process of sparking to the tissues as in cutting but the amount of heat (i.e. RF power) is significantly less so that the tissue temperature is fairly below that of cutting. The current waveform consist of RF bursts of narrow width recurring in time. During the off time of RF heat is allowed to disperse to adjacent tissues so that the cell temperature is kept below explosion level. This leads to clotting of the cell constituents by dessication & if prolonged (i.e. by time at appropriate power level or by excess power level for a given time) it is possible to char the tissues. A typical waveform of coagulating current is shown in following figure & in electrical terminology it is called repetitive bursts of RF current.

There are two sub-modes in coagulations :
A.2.1) Spray COAGULATION :
Spray coagulation with safe isolation quickly controls bleeding with minimal tissue destruction. We call it 'Super Spray'. That's because it provides superior control of bleeding with less depth of tissue necrosis and minimal destruction. Spray coagulation can be used to give rapid fulguration for virtually all types of procedures from delicate micro-surgery to demanding oncology and thoracic surgery.
Spray COAG is ideal for superficial coagulation. The surgeon can carry out fully non-contact work between the electrode and the tissue. Effective coagulation is possible even in irrigation fluid.

A.2.2) Point COAGULATION :
Precise Pinpoint Coagulation (or SOFT COAG.) is also achieved in monopolar mode & provides precise control of localized bleeding. So it is ideal for use in a small, defined area.

This mode lets you treat tissues both gently & very effectively. Also it has a benefit of reduced tissue adhesion to the electrode.
A.2.3) Force Coagulation :
Force COAGULATION mode can be applied for deep coagulation of tissues and also for standard coagulation. It is a very effective and relatively fast mode of coagulation, which is operated either directly with the coagulation electrode applied to the tissue or indirectly for example with a surgical clamp.

This mode lets you treat tissues both gently & very effectively. Also it has a benefit of reduced tissue adhesion to the electrode.
B) BIPOLAR Mode :
Bipolar procedure do not need the use of a patient plate. They generally use a forcep where each limb is electrically insulated from the other. Special independent RF generator with a low power output at a low impedance is provided so that coagulation only can be effected through a purely desiccation process and without any sparking (unlike fulguration type of coagulation.) The tissues to be coagulated are held between the lines of the forcep and current is applied. Local coagulation is achieved over the area held. Following image shows the arrangement for clarity. The current is restricted to the area under coagulation.

At times, the blood vessels after coagulation stick to the forceps tips and again tear off while removing forceps. This can be avoided only by switching off the RF current at proper time. Excessive dehydration on the tissue causes sticking of tissues to the forcep tips, hence mastery can only come through experience.
At times, when the forceps tips are not clean, no coagulation occurs since the RF current can not flow due to dried blood or tissue residue on the working surface of the forceps. The remedy is to keep the tips in metal, bright condition by frequently wiping the working surfaces.
There are two sub-modes in BIPOLAR :
B.1] Auto BP COAGULATION :
In the auto BP mode no footswitch is necessary and once the surgeon grips the tissues to be coagulated with the bipolar forceps the RF output is activated after a predetermined delay is meant for the convenience of the surgeon - to give him time to decide what he is going to coagulate. If he releases the tissues before the turn on delay is over them, the delay is automatically cancelled and he can look for a fresh further attempt. Once the RF is activated after the delay time of a few seconds coagulation proceeds ahead and stops automatically on completion.

B.2] BP CUT:
Bipolar CUT technology lets you nearly eliminate excessive current, even during precision cutting in minute tissue structure.

Safety Precautions :
a] Grounding :
While using any electro medical equipment proper grounding is mandatory in the interest of patient safety. The ground lead in the three pin mains cable is connected to the metal frame of the unit to avoid any current flow from the cabinet. It is the responsibility of the user to assure that the ground pin of the power plug receives proper ground from his electrical power outlet socket.
b] PPF Alarm :
Our Patient Plate Fault (PPF) detection technology protects patients from burns due to inadequate contact of the patient plate electrode.
The system is designed such that whenever patient plate is disconnected from the circuit, the monopolar generator output is deactivated & simultaneously an Audio-Visual (Red LED on dial) indication is provided.
c] While operating, the patient must be electrically isolated from the operation table or any other metal object..
d] The cables carrying high-frequency (HF) currents must not come in contact with the patient or with other cables.
e] Any other electrode (e.g. ECG monitor electrode) to be positioned on patient's body, must be placed away from the HF electrode.
f] As is known electro surgical cutting / coagulation takes place via the HF current applied to the tissues. Hence the procedures are inherently NOT explosion proof & therefore must not be used in presence of flammable anesthetics or similar environment.
g] The contact between the Inactive Electrode / Patient Plate and the skin must always be spread over a large surface area & the patient plate must be firmly positioned under the buttocks.
h] Ensure that the entire surface of the patient plate is in contact with the patient's skin, if necessary shave off some hair to achieve good contact. Never wrap the stainless steel patient plate with cloth or gauze pad. Always use KY-Jelly for better contact.
i] Areas which are not suitable for placing the patient plate,
1] Body parts with bony prominences or uneven surfaces or small area of the calf.
2] Areas with a thick layer of fat
3] Scar tissue
308, Bussa Industrial Estate, Off. Ferguson Road, Hanuman Lane, Lower Parel, Mumbai - 400 013, India Tel:         022 - 24922782 / 65803160
TeleFax: 022 - 24930853
Mail: info@jehangirmedical.com