Tuning into long-wave radio frequency therapy
Consider the benefits of adding this modality to your pain management and rehabilitation practice.
By Craig G. Wenborg
Non-ablative long-wave radio frequency is the use of electromagnetic waves for therapeutic purposes without damaging or destroying tissue. Radio frequency (RF) technology has evolved and now controlled specific application can be administered through a hand piece. Patients report a comfortable experience, accelerated healing, and positive outcomes in pain management.
How it works
Radio waves are a part of the electromagnetic energy spectrum. Electromagnetic energy is described as an electrical and magnetic disturbance traveling through space. Short wave diathermy is at the high-frequency end of the therapeutic radio wave spectrum. Long-wave radio frequency is at the low end.
Diathermy wave length is 27.1 MHz whereas long wave radio frequency is 0.5 MHz. Long-wave radio frequencies do not cause ionization.
Long-wave radio frequency is similar to diathermy electromagnetic energy in that waves move between plates called capacitors. The space between capacitors is called the dielectric. As energy travels between the capacitors, resistance to that flow causes an effect. With human tissue, that resistance results in hyperthermia.
Long-wave radio frequency is different from diathermy in its administration to the patient. Long- wave radio frequency does not readily travel through air as does diathermy. This allows for treatment approaches using a hand piece.
One of the capacitors is an application hand piece and the other capacitor is an appropriately placed return plate. Energy travels from the hand piece to the return plate. The dielectric is the tissue between the hand piece and the return plate. The hand piece surface area is smaller than that of the return plate surface area, which results in a hyperthermic therapeutic effect at the hand piece location.
Properties of treatment
Hyperthermia is defined as abnormally high tissue temperature induced for therapeutic effect. As early as 1962, research was indicating that long-wave radio frequency had positive effects on a variety of pain conditions.1,2 The therapeutic effects of RF are both thermal and non-thermal.
The thermal properties of RF include vasodilatation, increased blood profusion, washing out of tissue exudates, increased cell membrane permeability, increased tissue elasticity, increased tissue oxygenation, and accelerated macrophage and granulocyte activity. Non-thermal properties of RF involve the electro-conformational coupling model. In this model, membrane ATPases are able to directly absorb energy from oscillating energy fields and convert it to electrical bond energy in the form of ATP or chemical potential energy of concentration gradients.
RF is specific for tissue high in water content such as muscle. These tissues have a high dielectric constant, which creates greater resistance to the flow of energy.
Water molecules are bipolar and shift their alignment when exposed to an alternating wave current. The shifting of bipolar molecules and resistance to the flow of energy creates heat. The goal of therapeutic RF is to raise tissue temperature to 40 degrees Celsius, and hold that temperature for a pre- determined period.
Types of hand pieces
Hand pieces used for RF treatment come in monopolar and bipolar design. For physical medicine applications, the monopolar hand piece is ideal. Monopolar hand pieces direct RF energy from the hand piece to the desired tissue. The return plate location can be relatively distant from the emission hand piece. Energy can thus be directed through tissues to achieve deep heat penetration.
Bipolar hand pieces deliver energy from both capacitors in the same hand piece. That is, the energy emitting capacitor and return capacitor are located in the hand piece itself.
These hand pieces are not appropriate for physical medicine as the energy produced is superficial and does not reach deep into tissue.
There are two types of monopolar hand pieces: capacitative
electrical transfer (CET) hand pieces are coated with porcelain, while direct electrical transfer (DET) hand pieces use a metal plate to transfer electrical energy directly to the tissue.
With CET, electrical energy is absorbed by the porcelain and thus target-tissue penetration is approximately 20 millimeters. As much as 90 percent of the energy can be absorbed by the porcelain. With DET, nearly all of the energy can be directed into the tissues, with penetration of 40 millimeters or more.
Specific hand pieces have been developed for physical medicine applications. Human anatomy varies from large relatively flat regions to small concave areas. Hand pieces have been developed to treat these anatomical variants.
For orthopedic and sports injury treatment, two hand pieces will satisfy the majority of your needs: The 50- millimeter hand piece allows for treatment of large areas such as the hamstring, quadriceps, and paraspinal regions. The 30-millimeter hand piece is used for smaller areas such as paraspinal muscles and extremities.
Choosing the right generator
The speed at which you can attain the desired temperature is dependent on the RF generator. As this is an attended therapy, you will want to achieve timely results. Some RF generators can take up to an hour to reach desired heat goals.
The generator has to be able to rapidly raise tissue temperature and hold that temperature against heat dissipation associated with vascular wash out. Therefore, the appropriate RF generator for clinical use will have sufficient power output so that total treatment time for this modality should not exceed 15 minutes.
RF treatment involves decision making. You evaluate patients for their condition, the size of the area being treated, and the application hand piece to use. Take your time and communicate frequently with the patient to gauge his or her response to treatment.
The goal is to bring tissue to the desired temperature as rapidly as possible, and hold that temperature for the desired period of time.
Contraindications for the use of RF are both relative and absolute. Be cautious if RF therapy without modification would place the patient at undue risk. These cases include impaired circulation, blood clot, infection, metal implant, and impaired sensation.
Absolute contraindications are those that render RF inappropriate because patient risk cannot be mitigated. These would include treatment to the lens of the eye, testes, fetus, and tumor as well as over electronic devices such as pacemakers.
Coding for RF therapy
When providing RF therapy, you are actually providing two services. One service involves creating heat in muscle tissue through the passage of electro- magnetic currents, which is coded 97024.
The other service is the mechanical effect of manual lymphatic drainage, which is coded 97140. These codes allow for the billing of your time as well as supplies. When combined with your manipulative service codes, this therapy can help you achieve a strong billing level.
RF therapy is a safe and effective modality for treating pain, increasing circulation, and relaxing muscles. It can open a whole new world of mechanical and hyperthermic treatment approaches. Physical medicine practitioners of all types can benefit by adding RF therapy to their pain management and rehabilitation practices.
Craig G. Wenborg, DC, DABCO, is the chief clinical investigator for InterMED, manufacturer of the RF MYO radio frequency system. He is experienced in developing RF pain management case studies and establishing RF therapy educational curricula. He can be reached at 800-528-1026.
1Lehmann JF et al. Comparison of relative heating patterns produced in tissues by exposure to microwave energy at frequencies of 2450 and 900 megacycles. Arch Phys Med. 1962;43:69-76.
2Lehmann JF et al. Comparison of deep heating by microwaves at frequencies of 2456 and 900 megacycles. Arch Phys Med. 1965;46:307-314. by microwaves at frequencies of 2456 and 900 megacycles. Arch Phys Med. 1965;46:307-314.