Comprehensive Notes on Low-Intensity Direct Current (Microcurrent)
Low-Intensity Direct Current (Microcurrent)
Microcurrent is defined as any current with an amplitude less than 1 mA (10^{-3}A).
Waveforms are typically DC or monophasic pulsed current.
Other names include low-volt pulsed current, micro electrical neuromuscular stimulator, or micro electrical stimulation.
Micro amperage is insufficient to excite sensory or motor nerves.
APTA recommends the term low-intensity direct current (LIDC).
LIDC is typically DC or monophasic pulsed current in the micro amperage range.
Monophasic pulsed current pulse duration depends on frequency; a typical pulse duration is 500 msec (0.5 sec).
Frequency on LIDC stimulators varies from 1 to 1,000 Hz.
Because LIDC is DC or monophasic, one electrode is the anode and the other is the cathode.
Cell populations respond differently to anodal and cathodal stimulation.
LIDC originated from observations of micro amperage DC flowing out of injured tissue.
Outward flow indicates an electrical potential across the skin, called the transepithelial potential (TEP).
Transepithelial Potential (TEP)
TEP is created by the separation of ions across sheets of epithelial cells (i.e., skin).
TEP is distinct from the resting membrane potential of single cells.
Ions accumulating on opposite sides of epithelial tissue create TEP.
LIDC and TEP Summary
LIDC originated from micro amperage DC flowing out of injured tissues, indicating TEP.
TEP arises from ion separation across epithelial cell sheets.
*TEP is electrical potential created when ions accumulate on opposite sides of epithelial tissue.
Current Amplitude: Micro amperage range (insufficient to excite sensory or motor nerves)
Therapeutic Benefit: No therapeutic benefit from activating sensory or motor nerves (physiologically implausible)
Recommended Terminology: Low-Intensity Direct Current (LIDC)
Waveform Type: Typically, DC (Direct Current) or Monophasic Pulsed Current
Pulse Duration: For monophasic pulsed current, pulse duration typically 500 msec (0.5 sec), much longer than most other pulsed currents
Frequency Range: 1 to 1,000 Hz
Electrode Polarity: One electrode is the anode and the other is the cathode (due to the nature of DC or monophasic current)
Electrode Effects:
Anodal Stimulation: Positive effects on cell populations
Cathodal Stimulation: Negative effects on cell populations
Physiological Effect on Cells:
Anodal: May attract negatively charged ions, affecting certain cell populations
Cathodal: May attract positively charged ions, influencing other cell populations
Clinical Use: Often used for iontophoresis, wound healing, and pain management without nerve activation
Voltage and Current Considerations: Low voltage and microamp current typically used, no strong electrical field to stimulate motor or sensory nervesThe skin's external surface has a net negative charge, known as the skin battery.
Injury creates a pathway for positively charged ions to flow from deeper tissues to the skin surface.
The wound becomes the cathode due to loss of positivity.
Lateral currents of injury are created as positive ions flow toward the wound cathode.
Clinical use of LIDC aims to augment these endogenously produced currents of injury.
HVPC can result in current with micro amperage intensity at low pulse durations and frequency.
Increasing the frequency or pulse duration of HVPC can result in milliamperage intensity.
Electrode Types and Effects on Cell Populations
Anode (Positive)
Attracts negatively charged ions (anions).
Can induce cellular activation depending on cell type.
May stimulate tissue repair or wound healing.
Anti-inflammatory effects in some cases.
Cathode (Negative)
Attracts positively charged ions (cations).
Typically results in cell membrane hyperpolarization.
May influence nerve regeneration or pain modulation.
More likely to cause tissue damage if not carefully controlled.
Clinical Use of Microcurrent and Best Evidence
LIDC is used to stimulate epithelialization of tissues in a non-healing skin wound.
The cathode is placed over the wound site, with the anode placed adjacent to the wound.
Microcurrent as Alternating Current
Microcurrent uses both positive and negative polarities.
Current is measured in Micro Amps with an intensity of 175-1000.
The frequency of the microcurrent ranges from 0.1-680 Hz.
Galvanic Currents
Galvanic currents are used primarily for facial muscles
Galvanic currents use mild electric currents that consist of positive and negative ions to stimulate the local muscles.
The outcome of a galvanic current is maintaining the muscle physiology.
Continuous direct current (also called galvanic current) has been used for wound healing, iontophoresis, and in the treatment of denervated muscle.
Galvanic Treatment Types
Two major uses of direct current in skin therapy:
Iontophoresis.
DE incrustation.
Types of Direct Current Stimulation
Three different types of stimulation: anodal, cathodal, and sham.
Anodal stimulation is positive (V+) stimulation that increases the neuronal excitability of the area being stimulated.
Cathodal (V−) stimulation decreases the neuronal excitability of the area being stimulated.
Low Frequency Currents
Low frequency currents are therapeutically used currents whose frequency is in the range of 0 to 100 cycles per second.
The primary use of low frequency current is the stimulation of nerve and muscle.
Direct Current (DC) vs Alternating Current (AC)
Direct current (DC) occurs when the current flows in one constant direction. It usually comes from batteries, solar cells, or from AC/DC converters.
DC is the preferred type of power for electronic devices.
Alternating current (AC) occurs when the electric current periodically inverts its direction.
Microcurrent Frequency
Frequencies are set at two different levels; for example, one microcurrent channel might be set at 10 Hz, and the second at 40 Hz.
The technician will apply the current with a saturated towel or with skin patches.
It's very important for the patient to drink plenty of fluids before FSM treatment.
Microcurrent Contraindications
Microcurrent cannot be performed on clients with diabetes, epilepsy, a pacemaker, pregnant women, or anyone under the direct care of a physician.
Galvanic vs Microcurrent Treatments
Galvanic treatments utilize direct current to conduct active ingredients into deeper skin layers and perform deep cleansing, while microcurrent treatments use low-level alternating current to stimulate facial muscles, promoting collagen and elastin production
Galvanic Current Frequency & History
PULSE DURATION –more than 1ms which may be unto 300ms.
FREQUENCY-less than 50 Hz.
HISTORY- LUIGI GALVANI (1737-1798) discovered the Galvanic current in 1780s.
Rectangular, saw-tooth, triangular & trapezoidal.
Maximum Current Frequency
Nuclear gamma rays have frequencies above 10^{20} hertz, and you may model their emission as a result of AC currents flowing inside atomic nuclei.
Term 1: Microcurrent
Definition 1: Current with an amplitude less than 1 mA (10^{-3}A).
Term 2: Waveforms of Microcurrent
Definition 2: Typically DC or monophasic pulsed current.
Term 3: Other names for Microcurrent
Definition 3: Low-volt pulsed current, micro electrical neuromuscular stimulator, or micro electrical stimulation
Term 4: Micro amperage
Definition 4: Insufficient to excite sensory or motor nerves.
Term 5: Low-Intensity Direct Current (LIDC)
Definition 5: Typically DC or monophasic pulsed current in the micro amperage range.
Term 6: Monophasic pulsed current pulse duration
Definition 6: Depends on frequency; a typical pulse duration is 500 msec (0.5 sec).
Term 7: Frequency on LIDC stimulators
Definition 7: Varies from 1 to 1,000 Hz.
Term 8: Because LIDC is DC or monophasic
Definition 8: One electrode is the anode and the other is the cathode.
Term 9: LIDC originated from observations of
Definition 9: Micro amperage DC flowing out of injured tissue.
Term 10: Transepithelial potential (TEP)
Definition 10: Electrical potential across the skin.
Term 11: TEP is created by the
Definition 11: Separation of ions across sheets of epithelial cells (i.e., skin).
Term 12: TEP arises from
Definition 12: Ions accumulating on opposite sides of epithelial tissue.
Term 13: Anode (Positive)
Definition 13: Attracts negatively charged ions (anions).
Term 14: Cathode (Negative)
Definition 14: Typically results in cell membrane hyperpolarization.
Term 15: LIDC is used to
Definition 15: Stimulate epithelialization of tissues in a non-healing skin wound.
Term 16: Microcurrent
Definition 16: Uses both positive and negative polarities.
Term 17: Galvanic currents
Definition 17: Mild electric currents that consist of positive and negative ions to stimulate the local muscles.
Term 18: Outcome of a galvanic current
Definition 18: Maintaining the muscle physiology.
Term 19: Three different types of stimulation
Definition 19: Anodal, cathodal, and sham.
Term 20: Anodal stimulation
Definition 20: Positive (V+) stimulation that increases the neuronal excitability of the area being stimulated.
Term 21: Cathodal (V−) stimulation
Definition 21: V− stimulation decreases the neuronal excitability of the area being stimulated.
Term 22: Low frequency currents
Definition 22: Therapeutically used currents whose frequency is in the range of 0 to 100 cycles per second.
Term 23: Primary use of low frequency current
Definition 23: Stimulation of nerve and muscle.
Term 24: Direct current (DC)
Definition 24: Occurs when the current flows in one constant direction.
Term 25: undefined
Definition 25: Occurs when the electric current periodically
Electrode Types and Effects on Cell Populations
Anode (Positive)
Attracts negatively charged ions (anions).
Can induce cellular activation depending on cell type.
May stimulate tissue repair or wound healing.
Anti-inflammatory effects in some cases.
Cathode (Negative)
Attracts positively charged ions (cations).
Typically results in cell membrane hyperpolarization.
May influence nerve regeneration or pain modulation.
More likely to cause tissue damage if not carefully controlled.
Clinical Use of Microcurrent and Best Evidence
LIDC is used to stimulate epithelialization of tissues in a non-healing skin wound.
The cathode is placed over the wound site, with the anode placed adjacent to the wound.
Microcurrent as Alternating Current
Microcurrent uses both positive and negative polarities.
Current is measured in Micro Amps with an intensity of 175-1000.
The frequency of the microcurrent ranges from 0.1-680 Hz.
Galvanic Currents
Galvanic currents are used primarily for facial muscles.
Galvanic currents use mild electric currents that consist of positive and negative ions to stimulate the local muscles.
The outcome of a galvanic current is maintaining the muscle physiology.
Continuous direct current (also called galvanic current) has been used for wound healing, iontophoresis, and in the treatment of denervated muscle.
Galvanic Treatment Types
Two major uses of direct current in skin therapy:
Iontophoresis.
DE incrustation.
Types of Direct Current Stimulation
Three different types of stimulation: anodal, cathodal, and sham.
Anodal stimulation is positive (V+) stimulation that increases the neuronal excitability of the area being stimulated.
Cathodal (V−) stimulation decreases the neuronal excitability of the area being stimulated.
Low Frequency Currents
Low frequency currents are therapeutically used currents whose frequency is in the range of 0 to 100 cycles per second.
The primary use of low frequency current is the stimulation of nerve and muscle.
Direct Current (DC) vs Alternating Current (AC)
Direct current (DC) occurs when the current flows in one constant direction. It usually comes from batteries, solar cells, or from AC/DC converters.
DC is the preferred type of power for electronic devices.
Alternating current (AC) occurs when the electric current periodically inverts its direction.
Microcurrent Frequency
Frequencies are set at two different levels; for example, one microcurrent channel might be set at 10 Hz, and the second at 40 Hz.
The technician will apply the current with a saturated towel or with skin patches.
It's very important for the patient to drink plenty of fluids before FSM treatment.