What are Position of electrodes

 

Position of electrodes

In order to drive the electric field through the structure that needs to be treated, the electrode positions should be carefully considered. As much as possible, the electrodes should be placed so that the various tissues are in series with one another, or at an angle to the electric field, if the structure has a high impedance. The best way to heat a low-impedance structure is to align the tissues parallel to the field. Electrodes are often applied to the medial and lateral portions of the ankle joint during treatment in order to heat the joint and ensure that the tissues are in series with one another. When using a longitudinal application, the ankle area feels warm, but since the tissues run parallel to the field, the heating is actually mostly limited to the muscles and blood vessels. Therefore, this type of heating is appropriate for treating soft structures.

Optimal Electrode Positioning for Shoulder Induction

In order to avoid the field concentrating on the tissue nearest to the electrode, the electrodes should be positioned parallel to the skin. Since most lines of force would choose the shortest path through the insulating material between the electrodes and the skin, it should give significant impedance to the lines of force. This is known as a low dielectric constant. The electrodes may not lie parallel to one another if they are positioned parallel to the skin, but this has minimal bearing on the distribution of the field as long as the additional conduit connecting the electrodes' more widely separated sections passes through bodily tissues. The message symbolizes the lateral aspect of the shoulder, which is thinner above than below. The tissues have a high dielectric constant, which allows the lines of force to pass through them readily. The lengthier passage adds little more impedance.

Improving the Effectiveness of Deep Tissue Stimulation

An even field is produced even though the electrodes are somewhat angled when they are placed parallel to the skin. Deeply positioned structures can also be treated with the cross-fire technique, especially if they are located in highly vascularized regions like the pelvic organs. Because the vascular tissues have a very high dielectric constant and the part's cross-sectional area is larger than the electrodes, the field travels into the deep tissues, which subsequently heat up less than the superficial tissues. The deep tissues are exposed for twice as long as the skin because the field passes through the region in two directions.

Single-polar method

The indifferent electrode is put to a different area of the body or may not be utilized at all, while the active electrode is placed over the lesion site. Each electrode has its own electric field created beneath it, with force lines extending outward from it. As a result, the heating is just superficial and the field's density decreases with increasing distance from the electrode.

Cable technique

Utilizing a cable to apply short-wave diathermy allows for the simultaneous application of the magnetic field's (inducto thermy) and electric field's effects. The electrode, which completes the patient's machine circuit, is made up of a thick, insulated cable. The cable is positioned in relation to the patient's tissues, but an insulating barrier keeps it apart. A fluctuating magnetic field surrounds the center of the cable and an oscillating electrostatic field forms between its ends as a result of the high-frequency current oscillation. These fields influence the tissues that are contained inside them and are represented diagrammatically.

The field of electrostatics

The strong electrostatic field between the cable's ends affects the tissues in a manner akin to that which occurs when current is supplied via the capacitor field approach. Since the field distribution is governed by the same principles, some heating of the deeper-ly located, high-impedance structures should be achievable as long as an appropriate approach is employed. The heating tends to be most in the superficial tissues and those with low impedance.

The magnetic field

Any conductor that is crossed by the magnetic lines of force experiences electromagnetic fields (EMFs) due to the fluctuating magnetic field caused by the current oscillation. EMFs cause eddy currents when the conductor is a solid piece of conducting material. Tissues that are near to the cable's center produce these kinds of currents. Since the eddy currents are limited to low impedance tissues, they only generate heat in conductors, preventing subcutaneous fat from heating up. The superficial tissues are most affected, though, because the currents are generated closest to the conductor's surface, where the magnetic field is highest. Naturally, conduction and the circulation of hot blood cause some heat to be transported to nearby tissues, although these effects are mostly felt on the low-impedance surface tissues.

The two fields' respective effects

Experimental evidence has demonstrated that the electric field's effect predominates when the cable is wound around a high-impedance material, but the electromagnetic induction currents are largest when the cable is wound around a low-impedance material. Hence, the electric field between the ends of the wire is preferred to the magnetic field at its center when treating an area of high impedance, especially if deep heating is needed. The eddy currents created by the magnetic field in the center of the cable are used instead of the electric field when treating a low impedance area, especially if superficial heating is needed. Alternatively, both effects can be used simultaneously: an electric field is created between the ends of the cable and eddy currents around its center if the entire cable is positioned in relation to the patient's tissues.

Maximizing Cable Utilization for Limb Therapy

Typically, the cable is wound around the affected area when treating the limbs. Both electrostatic and magnetic fields are used when the area is large, such as the entirety of a limb or two limbs. Depending on the needed depth of heating and the resistance of the tissues, only the ends or the center of the cable may be employed for treating a smaller area. The electrostatic field between the cable's ends is most effective in high impedance areas. For example, in the case of the knee joint, two turns of the wire, one above and one below the joint, may be made.

Sufficient Cable Configurations for Multiple Joint Therapy

One end of the cable can be wound around one joint and the other end can be wound around the other joint, for example, while treating both shoulders. The center of the cable is employed if the area that has to be treated has low impedance, such as the muscles in the calf or thigh, because the eddy currents will generate enough heat there. The cable can be placed in a flat helix, two helices can be created from its ends, or a grid layout can be employed to treat a flat surface like the back. When using the grid, the electric field heats the tissues primarily since the magnetic field is complex and likely does not penetrate deeply. When using the other two approaches, however, eddy currents heat the tissues. Since they run perpendicular to the magnetic lines of force, the heating generated by a single helix appears in the tissues underneath the coil as a hollow ring.

Applying a Double Helix Coil to Therapy

Viewed from the side, the coil displays the magnetic lines of force as broken lines and the eddy currents as an arrow-depicted line. When looking at the coil from above, the area that produces heat is depicted by the shade. The magnetic lines of force connect the two coils when the double helix is employed. Heating occurs in the tissues between the two helices as a result of eddy currents, with the greatest heating occurring in the surface tissues where the magnetic field is strongest. It is important to maintain a suitable gap between the two helices to prevent severe heating that could result in burns. The two coils can be positioned similarly to condenser electrodes on opposite sides of the body or on a flat surface. One condenser electrode may be utilized in conjunction with the cable. When anteroposterior condenser electrode application is inappropriate due to flexion deformity, this technique can be applied to treat the hip joint.

Improving Hip Therapy with the Cable Approach

The cord is wound around the leg. The machine is connected to one end, and the other is insulated typically with crutch rubber at the other. On the side of the afflicted hip, a condenser electrode is positioned level with the sacrum to guide the electric field across the hip area. When treating a large region that cannot be covered by condenser electrodes, when the area is uneven, as in the case of hands with rheumatoid arthritis, or when it is preferable to prevent heating the subcutaneous fat, the cable approach can be helpful. The inability to use air spacing due to the skin's propensity to warm up limits the effect that can be achieved on the deep tissues, which is a drawback of the cable.

 

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