1. High Voltage Pulsed Current (HVPC)
Mohammed Taher Ahmed
Associate professor of PT
Mobile phone :

2. History of HVPC
In 1940 this current originally developed by Haslip in USA, and known as Dyna-wave.
In 1970s this current become popular and known as HVPC.
The first published paper on use of this current was by Young 1966, on edema reduction.
High voltage
developed in the 1940s and became commercially
available in the mid‐1970s
• The name of the device has changed and is now
more commonly called high voltage pulsed current
• HVPC is an electrical current with a monophasic
waveform
• There is a misconception that the current is called
“Interrupted Galvanic”, or “Interrupted Direct
Current”, because the waveform pulsed galvanic stimulators wereis monophasic

3. What is HVPC ? 1-Waveforme
1.1.Twin-peak monophasic pulse: Each pulse is made of a pair of monophasic (+/-) spike like waveforms that rising and falling rapidly, that reach maximum of mA.
1.2-Pulse duration: very short (5-200µS), usually µS
1.3.Very long inter-pulse duration of 9900µS
2-High voltage device: current voltage ranged from (0-500V), maximum voltages (150V).
3-Pulse frequency: 1-200Hz. Usually (1-120Hz)
The HPVC waveform allows for a high peak voltage
but a low average voltage, meaning the overall
amount of current the patient receives is very low
• The “high” in high voltage pulse current can be in
the order of 500 volts, but the average amount of
current is significantly less (measured in milliAmps
[mA] and turned up to patient tolerance)

4. Very Short Pulse Duration (5-200 µSec)3
No chemical effects
Stimulation is safe and comfortable than Faradic current
Maintained for longer periods of time (60minutes). 2
selectively stimulate motor rather than sensory nerves, so used for reduction of disuse atrophy. . 1
Not stimulate dennervated muscles as it can not depolarized membrane .
The pulse or phase
duration is quite narrow,
usually varying 50 – 200
μsec
• The interpulse interval is
large, helping to decrease
the overall amount of
current flow into the tissues
HVPC penetrates deeper than that of low-voltage currents.

5. Physiological effects
Wound Healing
Edema reduction
Pain Modulation
1. Decrease in pain
2. Decrease in swelling/inflammation/ Increase in local circulation
4. Facilitation of wound healing
5. Facilitation of muscle contraction
Muscles stimulations

6. Positive Polarity Negative Polarity Increases macrophages
Vascularity
Stimulation of fibroblastic growth
Collagen production
Epidermal cell migration
Inhibits bacterial growth .
Increases macrophages
Promotes epithelial growth
Facilitation of tissue healing
– change in endogenous voltage of tissues with monophasic waveform, which involves migration of cells toward the anode or cathode
– re‐establishing normal electric potential of the wound
– migration of neutrophils, macrophages, lymphocytes and platelets enhances the inflammatory phase of healing
Migration of fibroblasts enhances the proliferative phase of healing
– Local increase in circulation, bringing more oxygen and foodstuffs, and removing debris and waste products

7. Edema Reduction Muscle pump
Repeated muscle contraction (motor level stimulation) increase venous return & blood flow .
Fluid
Repulsion
Theory
Repulsion of protein rich fluid through microvascular exchanges (negative polarity).
Edema Control: Hz (muscle twitch)
Decrease in swelling/oedema
– Removal of vasoactive agents, debris and waste products from the injured area
– Increase in cell membrane permeability allowing more extracellular fluid to be resorbed
– Activation of motor nerves will bring about muscle contraction, thus enhancing the muscle pump effect
What makes HVPC more effective for edema management?
The net effects of these two mechanisms are to decrease edema

8. Pain modulation Improve circulation supra spinal Gate control
theory
supra spinal
stimulation
Improve
circulation
High frequency
(80-120Hz)
Low intensity HVPC
C-TENS
Low frequency
(10-20Hz)
High intensity HVPC
AL-TENS
Increase blood flow
Removal of waist product Reduction of inflammatory
process,
Decrease in pain
– Activation of pain‐gating mechanisms
– Stimulation of release of endogenous opiates
– Stimulation of descending pain suppression mechanism
– Removal of pain metabolites and vasoactive agents from injured area

11. THERAPEUTIC USES AND INDICATIONS OF HVPC
1-Wound healing
Pressure ulcer
Diabetic foot ulcer
Burn wound
2-Posttraumatic
Edema (fracture, burn).
Sprains & Strain
3-Musculoskeletal Pain
Chronic low back pain.
Osteoarthritis,

12. 1. Be cautious when using HVPC over an area with:
CONTRAINDICATIONS and PRECAUTIONS
Over neoplasic lesion.
Over area of extreme edema,
Over hemorrhagic area.
Over osteomyleities
Over anterior cervical area.
Over transcranial area.
Over electronic implants.
1. Be cautious when using HVPC over an area with:
a. Impaired sensation
b. Extensive torn tissue
c. Hemorrhagic area
2. Patients with epilepsy should be monitored during treatment.

13. Considerations for HVPC Application
Intensity ( motor and / or sensory)
Frequency (pulse rate); high or low pulse frequency.
Modes (continuously, reciprocal).
Polarity (positive, negative).
Electrodes Placement (monopolar/bipolar)
Treatment time ( minutes)
Frequency of treatment (daily /3 time per week)
HVPC requires the use of 2 electrical circuits in order
to conduct current to the patient
• The primary (active) circuit has positive or negative
electrodes in a 1, 2 or 4 electrode formation
• The secondary circuit is the dispersive circuit, where
the density of current is reduced in order that the
active circuit “feels stronger”
We need to address the issue of polarity when
applying HVPC to a patient. We will be using active
electrodes and a dispersive electrode
– Active electrodes will all be one polarity (‐ve or +ve)
– The dispersive electrode will be the opposite polarity
• HVPC must always use the dispersive electrode
outlet in order to complete the electrical circuit
Frequency
• Intensity of current
• Accurate localization of lesion/injury
• Accurate placement of electrodes
• Patency of circulation
• Intact neurological sensation
• Knowledge of underlying pathophysiology in relation to
desired outcome of treatment
• Contraindications and precautions to treatment

14. HVPC Application for Wound Healing
Cleaned and debrided the wound before application of HVPC.
Cover the wound with several layer of sterile gauze soaked in saline.
Active electrodes soaked in antiseptic solution
Active electrodes will be applied either
Directly over the wound
Directly in the wound periphery .
Dispersive electrodes are placed proximal to active electrode so that the current passes through the wound.

15. HVPC Application for Wound Healing
IF wound is infected used Negative electrodes (Cathode) Daily treatment (30-60minutes) IF wound is clean used Positive electrodes (anode) Day per day treatment (30-60minutes)
Before TTT
During TTT
After TTT

16. HVPC Application for Wound Healing
TREATMENT PARAMETER GUIDELINES
• Pulse frequency: 100 pps
• Pulse duration: about 100 μsecs
• Treatment intensity: 150 ‐ 200 V
• Treatment duration: 30 – 60 minutes; 3 ‐ 5 times/week
Before TTT
During TTT
After TTT

17. HVPC Application for Hand Edema Reduction
Technique 2 One active electrodes (negative polarity) were placed over the median nerve in the wrist crises, while another electrodes over dorsum of the hand, after being soaked in sterile 0.9% Na Cl, while the dispersive electrodes was placed over forearm area.
Technique 1 One active electrodes (negative polarity) were placed over the median nerve in the anticubital foss, while another electrodes over the ulnar nerve, at medial epicondyle, after being soaked in sterile 0.9% Na Cl, while the dispersive electrodes was placed over forearm area.

18. HVPC TREATMENT PARAMETER GUIDELINES
pain relief, most studies suggest the following:
• Place the cathode (‐ve) electrode(s) on or near the painful site (switch polarity if patient uncomfortable or pain is not diminished after 2‐3 treatments)
• Pulse frequency: between 80‐120 pps
• Pulse duration: about 100 μsecs
• Intensity: comfortable buzzing
• Treatment duration: 20 – 30 minutes

19. Self Questioning? Describe the waveform characteristics of HVPC
What are the 4 main indications for HVPC?
Describe the parameters for targeting pain control
What makes HVPC more effective for edema management?
How does the sensation of HVPC compare to TENS?
Pulse duration for HVPC
How is HVPC beneficial for wound healing?

20. HVPC FOR SWELLING I EDEMA
TREATMENT PARAMETER GUIDELINES
• Place the cathode (‐ve) electrode surrounding the edema are
• Pulse frequency: 120 pps
• Pulse duration: about 5 ‐ 20 μsecs
• Treatment intensity: strong buzzing (90% of visible muscle contraction)
• Treatment duration: 30 – 60 minutes; 3 times/week