The document discusses high frequency electrotherapy, defining high frequency currents as those above 500,000 Hz and detailing their medical applications including diathermy. It covers three types of diathermy: short wave, long wave, and microwave, highlighting their properties, physiological effects, and therapeutic uses in treating various conditions such as muscle pain and joint stiffness. The information emphasizes the importance of proper application for achieving safety and efficacy in medical procedures utilizing high frequency currents.

1. TOPIC:
HIGH FREQUENCY
ELECTROTHERAPY
BY-RACHIT KHERA
GROUP-6532

2. >Introduction to High Frequency Current:
“ A HIGH FREQUENCY CURRENT IS A CURRENT WHICH ALTERNATES SO
RAPIDLY THAT IT DOES NOT STIMULATE MOTOR OR SENSORY NERVES.
TO ACHIEVE THIS IT MUST HAVE A FREQUENCY OF MORE THAN
APPROXIMATELY 500,000 CYCLES PER SECOND / HERTZ AND IT IS
OFTEN TERMED AS OSCILLATING CURRENT.”
>Here Oscillation means Swinging TO AND FRO motion about a
mean position,
>In this Current, the electrons Swing To and Fro in the circuit.
High frequency ( HF ) / Radio frequencies are between
3 and 30 MHz.

3. =>TYPES OF OSCILLATIONS:
• 1: SUSTAINED OSCILLATIONS:
When oscillations of high
frequency current follow each
other closely ,said to be
sustained oscillations.
• 2:UNSUSTAINED OSCILLATIONS:
When there is a pause between
each group of oscillations , they
are unsustained oscillations.

4. • 3- DAMPED OSCILLATIONS:
When the amplitude of each
oscillation of the current is
less than its predecessor, then
the oscillations are DAMPED .
• 4-UNDAMPED OSCILLATIONS:
When amplitude of all
oscillations is the same, then
the oscillations are
UNDAMPED.

5. =>PROPERTIES OF HIGH FREQUENCY
CURRENT:

6. >High frequency currents in medical physics typically refer to alternating current (AC)
with frequencies above 100 kHz.
Some properties of high frequency currents in medical applications include:
1. **Tissue Penetration**:
High frequency currents can penetrate deeper into tissues compared to lower frequency
currents, making them suitable for certain medical procedures like diathermy and
electrosurgery.
2. **Tissue Heating**:
They generate heat within tissues due to the resistance encountered, making them
useful for thermal therapy, cauterization, and coagulation.
3. **Minimal Nerve Stimulation**:
High frequency currents can minimize nerve stimulation, reducing patient discomfort
during treatments.
4. **Enhanced Precision**:
They offer greater precision in targeting specific tissues or areas, making them valuable
in procedures requiring precise tissue ablation or coagulation.

7. 5. **Electrochemical Effects**:
High frequency currents can induce electrochemical reactions
within tissues, which can be utilized for tissue destruction or
modification in treatments like electrochemotherapy.
6. **Less Muscle Contraction**:
Compared to lower frequency currents, high frequency
currents typically induce less muscle contraction, which can
be advantageous in certain applications, such as aesthetic
procedures or pain management.
7. **Improved Safety Profile**:
They may have a lower risk of inducing cardiac arrhythmias
compared to lower frequency currents, making them safer
for certain medical interventions.
»These properties make high frequency currents valuable in
various medical procedures, ranging from surgical
interventions to non-invasive therapies. However, their
efficacy and safety depend on proper application and
understanding of their characteristics.

8. DIATHERMIA
»Diathermia is a Greek word meaning “ Through heating”.
DEFINITION: The use of non ionizing
electromagnetic energy
from the radio frequency spectrum as therapeutic agent.
≥ Diathermies are of following types:
(1) SHORT WAVE DIATHERMY
(2) LONG WAVE DIATHERMY
(3) MICROWAVE DIATHERMY

10. (1) INTRODUCTION TO SHORT WAVE
DIATHERMY (SWD):
• DEFINITION:
Short Wave Diathermy (SWD) is the use of
High frequency electromagnetic waves of
the frequency between 10^7 and 10^8 Hz
and a wavelength between 30 and 3 m to
generate heat in the body tissues. It
provides the deepest form of heat
available to the Physiotherapist.
The therapeutically used frequencies and
wavelengths are 27.12 MHz and 11 m
( commonly).
The less common frequencies and
wavelengths are 13.56 MHz and 22m.

11. PRINCIPLE OF SHORT WAVE DIATHERMY:
• The high frequency current is produced in
basic oscillator which is incorporated in
anode circuit of triode valve
• This current produces a similar high
frequency current in a second circuit, the
resonator circuit by electromagnetic
induction and by action of wireless waves.
• It is the current from this second circuit,
which is used for the treatment of patients,
thus oscillator and resonator circuits must
be in resonance with each other
• For this to occur the product of inductance
and capacity must be same for both
circuits.

13. INTRODUCTION TO LONG WAVE DIATHERMY
(LWD):
• Definition: Long Wave Diathermy ( LWD) is the use of high frequency electromagnetic
waves of the frequency 1MHz and wavelength 300 m.
COMPARISON OF LWD AND SWD
• It has the advantage over short wave diathermy that LWD has less frequency (1 MHz) than
short wave diathermy ( 27.12 MHz) hence there is minimal loss of energy
• The power output required for LWD is 25-75 watts only, whereas SWD generates 250-1000
watts of power
• Unlike SWD ,LWD doesn’t produce any interference with equipments
• => It is said that LWD can be used even with patients having metal implants. Also the
portability and affordability of equipment is good in LWD as compared to SWD.

14. PRINCIPLE OF LONG WAVE DIATHERMY
(LWD) :
• Long Wave Diathermy is
based on the Capacitor Field
Method.
• Long Wave Diathermy involves
generation at oscillating
electromagnetic field that are
comprised of both electrical
and magnetic fields.
• It can also work in heavy
voltage fluctuations.

15. Physiological Effects of LONG WAVE
DIATHERMY ( LWD):
• They include:
1. Increased blood Flow
2. Decreased Joint pain and
stiffness
3. Reduced inflammation
4. Accelerated wound healing
5. Increased Range of Motion
• INDICATIONS:
1. Osteoarthritis
2. Rheumatoid arthritis
3. Muscle Spasm
4. Back Pain.
5. Tendonitis
6. Myositis
7. Bursitis
8. Sprain and Strain
CONTRADICTIONS:
1. ULTER SENSATION
2. OPEN WOUND
3. PREGNANCY
4. VERY SERIOUS
PROBLEMS RELATED
TO LIVER AND
KIDNEY
5. HAEMORRHAGE
6. CARDIAC
PACEMAKER
PROBLEM
7. METAL IMPLANT

16. MICROWAVE DIATHERMY
Microwave diathermy uses
electromagnetic radio waves with
frequencies of 915 and 2456
MHz.14 On the basis of the
physical properties of these
waves and the corresponding
dimensions of the microwave
antennae, microwave diathermy
has two unique properties that
can be used to clinical advantage.

20. Applications and
therapeutics

21. Short wave diathermy
It is often used in physical therapy to relieve pain, promote
healing, and improve circulation.
Shortwave diathermy is commonly used to treat a variety of
conditions, including:
* Musculoskeletal injuries, such as strains, sprains, and muscle
spasms
* Chronic pain conditions, such as arthritis and fibromyalgia
* Soft tissue injuries, such as tendonitis and bursitis
• * Wound healing, such as in cases of delayed healing or

23. Long wave diathermy
This therapy is often used to treat muscle and joint
pain, stiffness, and inflammation.
• The electrical currents used in long wave diathermy can
penetrate several centimeters below the skin, making it
a effective treatment.

24. Here are some examples of conditions that may be treated with long wave
diathermy:
1. Muscle strains and sprains: Long wave diathermy can help to reduce muscle
pain.
2. Tendonitis: This therapy can help to reduce inflammation and pain in the
tendons, which are the tough cords that attach muscles to bones.
3. Scar tissue: Long wave diathermy can help to break up scar tissue and
improve mobility in injured areas.
• 4. Fibromyalgia: This therapy can help to reduce muscle pain and stiffness
in people with fibromyalgia.

26. Microwave diathermy
It is commonly used to treat muscle and joint pain,
stiffness, and inflammation.
Here are some examples of microwave diathermy
treatments:
1. Arthritis: Microwave diathermy can be used to relieve
pain and stiffness in joints affected by arthritis. The heat
can help reduce inflammation and improve joint mobility.
• 2. Tendonitis: Microwave diathermy can be used to treat
tendonitis, an inflammation of the tendons that connect

27. muscles to bones. The heat can help reduce inflammation and promote healing.
3. Muscle strains and sprains: Microwave diathermy can be used to treat muscle
strains and sprains. The heat can help reduce pain and inflammation, and
promote healing.
4. Bursitis: Microwave diathermy can be used to treat bursitis, an inflammation
of the fluid-filled sacs that cushion joints. The heat can help reduce
inflammation and promote healing.
• 5. Frozen shoulder: Microwave diathermy can be used to treat frozen shoulder,
a condition that causes stiffness and pain in the shoulder joint. The heat can
help reduce inflammation and improve joint mobility.

29. THANK YOU