Mohammed Taher Ahmed Associate professor of PT

E-Mail: MOMARAR@KSU.EDU.SA

Mobile phone : 0542115404

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.

2-High voltage device: current voltage ranged from (0-500V), maximum voltages (150V).

3-Pulse frequency: 1-200Hz. Usually (1-120Hz)

1.2-Pulse duration: very short (5-200µS), usually 50-120µS 1.3.Very long inter-pulse duration of 9900µS

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 300-400mA.

1

Not stimulate dennervated muscles as it can not depolarized membrane .

2

selectively stimulate motor rather than sensory nerves, so used for reduction of disuse atrophy.

.

3

No chemical effects

Stimulation is safe and comfortable than Faradic current

Maintained for longer periods of time (60minutes).

Very Short Pulse Duration (5-200 µSec)

HVPC penetrates deeper than that of low-voltage currents.

Muscles stimulations

Pain Modulation

Edema reduction

Wound Healing

Increases macrophagesPromotes epithelial growth

– IncreasesVascularityStimulation of fibroblastic growthCollagen productionEpidermal cell migration

– Inhibits bacterial growth .

Positive Polarity

NegativePolarity

MuscleMusclepumppump

Repeated muscle contraction (motor level stimulation) increase venous return & blood flow

.

FluidFluid RepulsionRepulsion TheoryTheory

Repulsion of protein rich fluid through microvascular exchanges (negative polarity).

Edema Control: 5-20 Hz (muscle twitch)

The net effects of these two mechanisms are to decrease edema

What makes HVPC more effective for edema management?

Gate control theory

supra spinal stimulation

Improve circulation

High frequency (80-120Hz)Low intensity HVPCC-TENS

Low frequency(10-20Hz) High intensity HVPCAL-TENS

Increase blood flowRemoval of waist product Reduction of inflammatory process,

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,

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 sensationb. Extensive torn tissuec. Hemorrhagic area

2. Patients with epilepsy should be monitored during treatment.

1. Intensity ( motor and / or sensory)2. Frequency (pulse rate); high or low pulse

frequency.3. Modes (continuously, reciprocal).4. Polarity (positive, negative).5. Electrodes Placement

(monopolar/bipolar)6. Treatment time ( 10-60 minutes)7. Frequency of treatment (daily /3 time per

week)

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.

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

Before TTT During TTT After TTT

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‐

Technique 1One 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.

Technique 2One 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.

HVPC Application for Hand Edema HVPC Application for Hand Edema ReductionReduction

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

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?

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