high voltage pulsating current or super imposed current

3. I
 HAFSA KHALID
 MARYAM KHALID
 LAIBA ROOP PAUL
 AQSA MUSHTAQ
 LAREB SATTAR
 SABIHA MANZOOR

5. Introduction
 HVPC used in therapy for many years in many
countries.
 It is highly popular in other countries
 HVPC delivers monophasic current so the polarity of
each electrode is known.
 It is a versatile form of electrical stimulation
 It has wide variety of uses (Muscle reeducation, nerve
stimulation, Edema reduction, pain control)

6.  HVPC generator produces:
 twin peaked waveform (pulses in duplets)
OR
 a train of two single pulses having a short phase duration and
long interpulse interval.
 Interpulse interval is much longer than pulse duration

7.  Low pulse charge requires an output voltage of
approx. 150 V or more to stimulate motor or sensory
nerves i.e. high peaked voltage up to 500 V typically
between 150-500 V
 Short phase duration allow activation of sensory and
motor nerve at a low intensity without stimulating pain
fibers.

8. Definition
 The high volt pulsed galvanic stimulator (HVPGS), a
type of neuromuscular stimulator is a short duration
(microsecond), microamperage current driven by a
high voltage current (up to 300 volts) that is delivered
as a twin-peak monophasic waveform of fixed
duration (100 microseconds).
 This direct current can produce both a mechanical
contraction and a chemical change within the body.

9.  HVPGS is the use of a high driving voltage (up to
500V) to produce analgesia, muscle contractions, and
to facilitate wound healing.
 Galvanic stimulation combines very short pulse
duration (of constant intensity) and high peak voltage,
yet low total current per second, to give relative
comfort and avoid tissue damage while stimulating
deep tissues.
 It is also an efficient means of exciting nerve fibers

10. Parameters
 Current type:
(A) Direct current
(B) Monophasic pulsed DC
(C) Symmetric biphasic pulsed
(D)Twin peak monophasic
 Amplitude: 0-500 ma
 Voltage: 150-500 Volts
 Pulse Frequency : 1-120 Pulse/sec
 Pulse Duration: 13-100 ms
 Phase Duration: 13-100 ms

11. (A) direct current (B) monophasic pulsed DC (C) symmetric biphasic
pulsed (D)twin peak monophasic

12. Waveforms
 Saw tooth
 M-wave
 Square Wave

13. Treatment duration
 Typical duration of HVPC is 15-30 min and the
treatment may repeated as many time as day needed

14. MODES:
A MODE SWITCH CAN CHANGE THE PATTERNS OF
CURRENT:
1. In continuous mode: The train of twin pulses are
delivered continuously.
2. Reciprocate mode: Refers to the alternate
application of train of pulses to one or other of two
active pads and does not mean that current
direction is reversed
3. Surge mode: Gives a train of pulses whose
intensity is gradually increased

15. Physiological effects
 Maintaining or increasing range of motion.
 Re-educating muscles.
 Edema/swelling/inflammation reduction.
 Reducing motor spasticity.
 Increasing local blood circulation to injured area and
promoting fluid movement to and from treatment area.

16.  Preventing or retarding muscle disuse atrophy.
 Managing chronic/post-traumatic/post- surgical pain
conditions allowing patient to participate in their pain
management program.
 Stimulation and acceleration of wound healing by
promoting blood circulation to wound.

17. Uses
1. Wound healing
2. Muscle Stimulation
3. Edema Reduction
4. Reduction of muscles spasm
5. Pain modulation

18. 1. Wound healing
 This current is formed to cause healing of the wound
and ulcer.
Induce human fibroblast
Increase rate of DNA and
protein synthesis
Hence healing occurs

19.  Positive electrode is used as active electrode if wound
healing is free from infection.
 This is because of the biophysical effects on wound
healing are polarity specific.
Blood clots /infection
pH acidic (+)
Hence cathode is used

20.  To account for the effects of polarity during the
treatment of cutaneous wounds the application of 20
min of negative polarity by 14 min of positive polarity
stimulation has been recommended .

21. • NOTE: depending upon the polarity of electrode
leucocytes, epidermal cells, fibroblast are attracted to
the area and level of collagenase increases.
• HVPS inhibits the growth of bacteria in infected
wounds.
• No changes in Ph and temperature that could effect
wound healing are not seen.

22.  Negative polarity helps in dissolving blood clots and
increases inflammatory byproducts, promoting healing
of the tissues.

23. 2. Muscle stimulation
 The current is used for stimulation of innervated
muscle as the pulses are very short(short pulses at
high intensity are more selective in stimulating motor
rather than pain nerves).
 HVPS is used both for strengthening as well as
reduction of disuse atrophy.
 Frequency of 30 Hz has been used.

24. 3. Edema reduction
 Rhythmical muscle contraction and release
due to the HVPS on motor nerve produces a
pumping effect and increased blood flow in
muscle and tissues and helps in draining in
edema and direct effect on the ANS leads to
local vasodilation, increase fluid exchange
thereby reduces edema .

25. 4. Reduction of spasm
 Ability of HVPS to stimulate innervated muscle has
leads to recommendation of this current in the
treatment of muscle spasm and enhance joint
mobility.

26. 5. Pain modulation
 Mechanism of pain relief brought about by this current
is the same as involved in the gate control theory of
pain.
 Since both the frequencies and intensities of HVPS
can be controlled. It is possible to apply both the high
frequency and low intensity stimulation for pain gate
control and low frequency or high intensity stimulation
for opiate release in descending pain suppression