High Voltage Pulsed Current (HVPC) Parameters and Applications
1.
2.
3. • Introduction
• Parameters of HVPC
• Waveforms used in HVPC
• Output Modulation
• Treatment Time for HVPC
• Electrode Configuration for HVPC
• Indications
• Uses
• Precautions
• Contraindications
4. • 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)
5. • 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.
6. • 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.
7. • Current type: 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. • Typical duration of HVPC is 15-30 min and the treatment may
repeated as many time as day needed.
12. • HVPC is applied using either a monopolar or bipolar
technique .
1. MONOPOLAR TECHNIQUE
Given over a wide area.
In sensory level pain control.
13. 2. BIPOLAR TECHNIQUE
To produce specific muscle contraction.
In motor level pain control.
14. • Peripheral nerve reeducation .
• Delay of denervation.
• Disuse atrophy by stimulating muscle contraction.
• Reduction of post-traumatic edema.
• To increase local blood circulation
15. Restoring of range of motion.
Reduction of muscle spasm.
Inhibition of spasticity.
Re-education of partially denervated muscles.
Facilitation of voluntary motor function.
16. CHARACTERSTICS OF A PULSE
• The twin pulse wave form has almost instant rise with
exponential fall.
• The pair of pulse(twin current) last only a few
microsecond.
• the shape and duration are normally fixed.
• very high voltage is needed to provide a high enough
current to stimulate nerve fibers
17. Such currents can easily pass through tissues as they
are comfortable and brief.
They have wide discrimination between sensory motor
and nociceptive nerve fibers.
Frequency, intensity and polarity can be altered by a
mode switch.
Current is applied through flexible electrodes and
sponges.
18. 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.
20. • 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
21. 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
22. • 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 .
• 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.
23. Negative polarity helps in dissolving blood
clots and increases inflammatory byproducts,
promoting healing of the tissues.
24. • 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.
25. • 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 .
26. • Ability of HVPS to stimulate innervated muscle has leads to
recommendation of this current in the treatment of muscle
spasm and enhance joint mobility.
27. • 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.
28. Parameters Gate Control Opiate Release
Output Intensity Sensory Level Motor level
Pulse Frequency 60-100 pps 2-4 pps
Mode Continuous Continuous
Electrode
arrangement
Monopolar/Bipolar Monopolar/Bipolar
Polarity Acute-Positive
Chronic-Negative
Acute-Positive
Chronic-Negative
Electrode
Placement
Directly over
painful site
• Painful site
• Trigger Points
• Acupuncture
points
29. • Stimulation of muscle can cause unwanted tension on the
muscle fibers, tendons or bony insertions.
• If frequency is too high then muscle will fatigue rapidly.
• Improper use can cause electrode burns or irritation.
• Intense or prolonged stimulation may result in muscle
soreness.
30. • Pacemaker implants
• Arterial Diseases
• Uncontrolled hemorrhage
• Blood Clots (DVT: Deep Vein Thrombosis)
• Pregnancy
• Cancerous Lesions
• Exposed metal implants
• History of Seizures
• Sensory impairment
• Unstable fractures