INTRO TO ELECTROTHERAPY (TYPES OF CURRENTS)

Principles of ES: Types of currents

AC

DC

PC

Principles of ES: Characteristics of currents

Qualitative

Quantitative

Principles of ES: Traditional & commercial designation of currents

Faradic

Galvanic

Russian

HVGC

Interferential

Diadynamic

Direct current is aka

Galvanic current

An uninterrupted flow of charged particles in 1 direction of about 1 s or longer

DC

Direct current is used for

Iontophoresis

Wound healing

Stim of denervated m

DC Modulations

Reversed DC

Interrupted DC

Surged DC

Continuous or uninterrupted, bidirectional flow of charged particles

AC

AC: Current that changes in direction of flow with reference to __ at least _

zero baseline

once per second

AC is used for

Promote soft tissue & osseous tissue regeneration

Management of pain

AC Modulations

Time-modulated AC

Amplitude-modulated DC

Uni or bidirectional flow of current that periodically ceases for a finite period of time

Pulsatile Current (PC)

PC is characterized by __ in current flow

periodic interruptions

Most commonly used type of current

PC

Pulse

Isolated electrical event

Separated by a period of time from the next event

represents a finite period of charged particle movement

Qualitative Characteristics

Waveform

Number of Phases

Symmetry

Phase charge balance

Visual representation of the pulse on a current vs. time plot

Waveform

Shape of waveform

Geometric

Rectangular

Square

Triangular

Sawtooth

Spiked

Mathematical function that would give rise to a shape

Waveform: Sinusoidal

Represents current flow in 1 direction or a finite period of time

Phase

Refers to unidirectional current flow on graph

Number of Phases

Monophasic:

Biphasic:

Polyphasic:

1 pulse, 1 phase

2 pulses, 2 phases

many phases, 1 pulse

Symmetry

Symmetrical

Asymmetrical

• Balanced phase charge

• Unbalanced phase charge

Amplitude-dependent

Peak Amplitude

Peak-to-peak amplitude

Max current/voltage delivered in 1 phase of a pulse

Peak amplitude

Max current reached in a monophasic pulse / each phase of a biphasic pulse

peak amplitude

Max current measured fr peak of 1st phase → peak of 2nd phase in a biphasic pulse

Peak-to-peak amplitude

Time dependent

Phase Duration

Pulse duration

Interphase interval

Interpulse interval

Rise time

Decay time

Old term of pulse duration

pulse width

Elapsed time bw start & end of 1 phase

Phase Duration

Elapsed time bw start & end of all phases in a single pulse

Pulse Duration

AKA intrapulse interval

Interphase Interval

Elapsed time bw 2 successive phases

Interphase Interval

Elapsed time bw 2 successive pulses

Interpulse Interval

Time for leading edge of the phase to inc from zero to peak amplitude of 1 phase

Rise Time

Time for trailing edge of phase to return to zero from current peak amplitude

Decay Time

% of total time that the current is ON

Duty Cycle

Period is _ + _

Pulse duration + interpulse interval

Elapsed time fr a reference point on 1 pulse → identical point on the next pulse

Period

Inversely proportional to frequency

Period

# times per sec a waveform repeats itself

# pulses per sec (pps)/cycles per sec (Hz)

Frequency / pulse rate

Amplitude & Time-dependent Variables

Phase charge

Pulse charge

# electrical energy delivered → tissue c each phase of each pulse

Rep by the area under a single phase

Phase Charge

Sum of all phase charges in the pulse

Rep by the area under a single pulse

Pulse charge

Current flow per unit of time

Average current aka total current

Average current

amt of current delivered to tissue per sec

Automatic sequential variation in current parameters

Current Modulation

Types of current modulation

Frequency Modulation

Ramp Modulation

Duration Modulation

Burst Modulation

An uneven alternating surged current with a pulse duration of 1 ms at a frequency of 50 Hz primarily followed by damped oscillation of 1000 Hz

Faradic current

A triangular/square wave pulses from 0.2 to 1ms pulse duration with a frequency of 50 Hz selectively surged

Faradic Current

asymmetric biphasic pulse of short duration (1ms) more comfortable then galvanic current

Faradic Current

2500 Hz is modulated to yield 50 burst per second. Each burst is actually a polyphasic pulse waveform “time modulated AC”

Russian current

HVPGC

High-Voltage Pulsed Galvanic Current

HVPGC: High voltage: used to __ skin impedance

dec

HVPGC: ___ -current amplitude _ waveform c _ phase duration (up to _ usec)

2 high peak

monophasic

short

200

HVPGC: Monopolar twin peak c instantaneous _ & _ on downslide.

_ is needed to stimulate n. Axons

Rise & slow

Dual peak

1k Hz burst-modulated AC current delivered in 4msec bursts

Aussie Current

Aussie current: Greater __ prod & _ rate of m. fatigue compared to the _

torque

dec

russian current

Physiologic responses to ES: Biological effects

Electrochemical

Electrophysical

Electrothermal

Physiologic responses to ES: Physiologic model

Cellular level

Tissue level

Segmental level

Systemic level

Physiologic responses to ES: Physiological correlates

Excitatory effects

Non-excitatory effect

Electrochemical effects

Polarity forms new chemical compounds

Faradays law

What law?

Amt of chemical reaction is _ prop to quantity of electricity passing thru _

Faradays law

directly

electrolytic solution

Arrange the ff currents fr highest → least # of electrochemical effects:

Direct current

Interrupted DC

Monophasic PC

Unbalanced Biphasic PC

Symmetrical Biphasic PC (cancels out, net = 0)

What effect: Causes ionic mvts including electrolytes & non-dissociated molecules

Electrophysical (electrokinetic) effects

Secondary to electrophysical effect

Electrothermal effects

Electrothermal effects: Microvibration along with friction produces _

heat

Law under electrothermal effects

Joule’s Law

What law?

Num of heat production (H) is prop to _, the _ , & _for which the current flows

Square of the total current (I^2)

Resistance (R)

Time (t)

Physiologic model: Cellular level

Excitation of peripheral n

Changes of membrane permeability

Modification of fibroblast, fibroclast, osteoblast, osteoclast formation

Modification of microcirculation and capillary flow

Changes of protein and blood-cell concentration

Alteration of enzymatic activity

Enhancement of protein synthesis

Modification of mitochondrial size and concentration

Physiologic model: Tissue level

Skeletal m contraction (force, contraction speed, reax time, fatigability)

Smooth m contraction or relaxation and its effect on BF

Tissue regen & remodeling

Changes in tissue thermal and chemical balance

Physiologic model: Segmental level

M grp contraction and its effect on joint mob & synergistic m activity

M pumping action effects on macrocirculation

Alteration of lymphatic drainage and arterial BF not associated c muscle contraction

Physiologic model: Systemic level

Analgesic effects associated c endogenous polypeptides

Analgesics effect d/t neurotransmitters

Circulatory effects associated c polypeptides

Modlation of internal organ act such as kidney & heart functions

Physiological correlates of ES: Excitatory effects (physiologic targets)

Sensation (sensory level response)

Skeletal m contraction (motor level response)

Pain (noxious level response)

• Subliminal excitation/microcurrent

Physiological correlates of ES: Non-excitatory effects

secondary to electrothermal/electrophysical effects

Bone growth

Wound healing

Edema

Protein synthesis

Scar tissue remodeling

Joules law formula

H = 0.24 I^2Rt