more than 10000 cycles/second. • Used as Therapeutic Current. • Produce deep heat in the tissues. E.g. Short Wave Diathermy Long Wave Diathermy Ultra Sound Microwave Diathermy 2 6.01 - 6.03 Short Wave Diathermy
107 to 108 Hz and wave-length between 30 and 3 meters. • But commonly used for medical purpose has frequency of 27.12 MHz and wave- length of 11 meters. 4 6.01 - 6.03 Short Wave Diathermy
current required for SWD purpose by mechanical device which causes sufficiently rapid movement to produce High frequency current. • Therefore, this type of current is obtained by discharging condenser through an inductance of low ohmic resistance produces the high frequency current with desired frequency & wavelength. 5 6.01 - 6.03 Short Wave Diathermy
both are coupled to get proper effect. • Machine/oscillator circuits: produces high frequency current and amplifies its intensity. • Patient/resonator circuit : it is coupled with the machine circuit and transfers electrical energy in form of electrostatic and electromagnetic fields to the patient. 7 6.01 - 6.03 Short Wave Diathermy
• High frequency current generated by circuit, which consist of a capacitance & inductance whose dimensions are arranged to allow electron oscillation at precise frequency, i.e- 27.12 MHZ. 10 6.01 - 6.03 Short Wave Diathermy
only on electrical size, Which is the product of Capacitance (C) & Inductance (L) : • F=1/√2π.LC • Main function is to give an amplified AC , that has a very high frequency of 27.12 MHZ & Wave Length of 11.06 meter. 11 6.01 - 6.03 Short Wave Diathermy
machine circuit by inductors and high frequency current is produced by electromagnetic induction. • Maximum current will flow if both the circuits are in resonance with each other. • And for this product of the conductance and inductance must be same in both the circuits. 14 6.01 - 6.03 Short Wave Diathermy
on the equipment glow • An ammeter wired into the circuit shows maximum reading that is diminished by turning the knob • A neon tube placed within the electric field will glow at maximum intensity when both the circuits are in resonance. 17 6.01 - 6.03 Short Wave Diathermy
o TO AND FRO/IONIZATION o In our body, there are number of charged molecules. In presence of SWD field, there will be attractive and repulsive forces causing acceleration of charged molecules along the lines of electric force. The charged molecule oscillate and kinetic energy is converted into heat. 18 6.01 - 6.03 Short Wave Diathermy
dipolar molecules in our body. Under the influence of alternating field of SWD, the positive pole of the molecule moves towards the negative pole of the electric field and vice-versa. This ultimately causes rotation of the dipoles and heat production. 19 6.01 - 6.03 Short Wave Diathermy
non-polar molecules. In them the electrons are firmly held to nucleus and are not displaced easily. The alternating electric field causes distortion of the electron cloud and thus production. All these procedure produces heat in accordance to Joules’ law. 20 6.01 - 6.03 Short Wave Diathermy