<p> Chapter 16. Diathermy</p><p>What Is Diathermy? • Prefix dia = • Suffix therm = • High-frequency ______that is primarily used to generate heat into body tissues • Involves ______and ______of EM by the body • Heat is produced by the ______of tissue to the passage of energy.</p><p>Why Is Diathermy Not Often Used in Sports Medicine? • – Shortwave diathermy units range from $5,000 to $25,000, making them prohibitive for many situations. • Poor information – Many of the contraindications regarding diathermy use are based on speculation. • Lack of research – Diathermy studies performed before 1970 were done on equipment that was not of caliber.</p><p>Classifications of Diathermy • Surgical – • Medical – Three types •  1 MHz, or 300 m  Oldest method  Not used anymore •  27.12 MHz, or 11 m  Wave identical to a shortwave radio  Most common type used in sports medicine •  2450 MHz, or 12 m  Similar to radar  Seldom used in United States  More contraindications than shortwave Shortwave Diathermy (SWD) • Shortwave diathermy device is basically a • Components • Generator: </p><p>• Drum: </p><p>• Three frequencies • • • </p><p>How Does SWD Work? • As the radio frequency exits the drum, an oscillating magnetic field is produced in the body. • As the magnetic field passes through the tissues, it causes reactions in the tissues.</p><p>Applicators or Drums • Most common type of SWD applicator is the induction drum electrode • Drum electrode is made up of </p><p>Shortwave (SWD) vs. Microwave (MWD) – – 2456 and 915 MHz</p><p>– Heating mainly owing to magnetic – Heating mainly owing to fields</p><p>– Penetrates – If fat is <0.5cm; MWD can go 5 cm deep. – At >0.5 cm penetration, temperature is ______of SWD</p><p>– Can apply directly to skin – Spacing required</p><p>– Doesn’t heat up metal as much as – No metal MWD – Most commonly used in sports – medicine</p><p>SWD Device • Shortwave units can either be one-drum or two-drum setup. • A one-applicator unit is called a • A two-applicator unit is called a • Inside the applicator drum is a single copper electrode (with high ______) shaped into a coil.</p><p>How Does Diathermy Work? • Runs on 110 V electricity from a wall outlet • Generator converts ______electricity to ______frequency, which is usually ______MHz. • ______frequency then passes through an inductive applicator (______). • As the high-frequency electrical energy is applied to the ______, a fluctuating ______field is generated around the ______. • As the ______frequency exits the ______, an oscillating ______field is produced in the body. • As the ______field passes through the tissues, it causes reactions in tissues, producing both ______and ______effects.</p><p>Two Ways in Which Diathermy Heats Tissues • (1) • Molecule whose ends carry opposite charges. • The ______wave produced by SWD causes rotation of dipoles • As these rotation, ______occurs, resulting in ______</p><p>• (2) • A ______field generates small ______fields. • Fields ______and increase cell ______, which causes ______• When a body part is placed within the ______field, electrical currents are induced within that conductor (tissue). • Within the body part, small eddy currents move in the direction of the ______field. • Rotation, movement, and vibration of ______in the tissues result in heat. • Greatest eddy current activity occurs in tissues high in ______(blood and muscle).</p><p>Energy Distribution and Heating Effects on Various Tissues Via SWD </p><p>Types of Diathermy • Continuous • • • Pulsed • • Physiological Effects of SWD • Increase blood flow, up to 30 mL/g of tissue – Comparable to • Increased • Decreased • Decreased • Increased ______cell infiltration • Realignment of ______and collagen content to increase ______• ______activity • Collagen deposition • New capillary growth • •</p><p>SWD: Indications • Strains • Sprains • Contusions • Tendinosis • Bursitis • Pain • Resolution of inflammatory infiltrates and exudates • Joint stiffness • Osteoarthritis • Decreased ROM • Increase extensibility of collagen fibers</p><p>SWD: Contraindications • More contraindications with Diathermy than any other modality • So why not just use ultrasound instead? • When tissue temperature rise is not indicated • Ischemic areas • Anesthetic areas • Effusion • Eyes (or contact lens) • Testes, ovaries • Caution over pelvis during pregnancy • Over moist wound dressings • Fever • Epiphysis • Cancer • Pacemakers • Metal implants (pins, screws)</p><p>Typical Diathermy Control Panel</p><p>1. Press power button on. 2. Select mode. 3. Press treatment button on. 4. Unit will turn off in 20 min, unless clinician adjusts time.</p><p>Application Procedures for Diathermy • Obtain history (condition, contraindications). • • • If indicated, drape with toweling. • Place electrode drum on treatment area. • • Set pulse duration (μsec). • Set pulse frequency (pps). • Adjust intensity. • Set treatment time (15–30 min). • • • When timer shuts off, terminate treatment. • Assess treatment efficacy. • Record treatment parameters. Thermal Ultrasound vs. SWD • Can heat tissues ____–___ cm deep • Can heat tissues ____–___ cm deep to >40°C to >40°C</p><p>• Heats ______areas • Heats ______areas</p><p>• Short stretch/thermal window • Long stretch/thermal window – – </p><p>• Edema reduction of small areas and • Decrease acute inflammation and joints edema of </p><p>• Stimulate • Stimulate tissue healing of </p><p>• Tigger point acute • Decrease pain in </p><p>• Acoustic • Magnetic • Stable </p><p>• • – Cell membrane permeability – Cell membrane permeability owing to mechanical effect on cell owing to electrical effect on cell Ca+ Ca+ gating gating</p><p>A few contraindications A few more contraindications Couplant required No Possible disrobing Can be applied over most clothing Easy to use Less affordable Monitoring by clinician Heats small areas Retains heat Retains heat _____ to _____ times longer</p>