ELECTRICAL CURRENT FOR TISSUE HELALING

Tissue healing 2

Chronic wound healing (ex. pressure ulcer) faster !

Mechanism - attraction of appropriate cell type of area - activation of theses cells by altering cell membrane function - modification of endogenous electrical potential of the tissue in concert with healing potentials.

- reduction of edema- enhancement of antimicrobial activity, and promotion of circulation

Galvanotaxis (전기 주성)- attraction to the negative pole : activated neutriphil, lymphocyte, platelet, mast cell, keratinocyte, fibroblast → negative electrode : inflamed or infected wound healing을 촉진

- attraction to the positive pole: inactive neutriphil, macrophage, epidermal cell → positive electrode : to promote healing of wound with no inflammation

Tissue healing 3

To enhance fibroblast replication and Increase the synthesis of DNA and collagen by fibroblast (voltage dependent)

- proposed mechanism ?

Injured tissue : positive charge relative to the surrounding uninjured tissue →returning to normal only after the wound closes

to promote tissue healing through antimicrobial activity - monophasic current ex. Microampere level DC and HVPC - bacterial growth를 억제하기 위한 ES는 much higher voltage 또는 much longer times 적용

to promote tissue healing by increasing circulation during or after the stimulation

Parameter for ES for tissue healing 4

Electrode placement

Waveform

Polarity

Pulse duration

Frequency

On:off time

Current amplitude

Treatment time

5

Figure 08-12. 13 Electrode placement to promote tissue healing.

Electrode placement

Monophasic waveform

HVPC

LIDC

Waveform 6

DC dual peak pulse

장점

맥동 기간이 짧고, 순간 전압이 높아 통증이나 조직 손상을 유발하지않고 효과적으로 심부조직을 자극할수 있다.

특징

High-voltage pulsed current (HVPC)7

Polarity8

Polarity of the electrode on or nearest to the wound

: wound healing의 특정 단계, infection or inflammation 유무에 따라 결정

- Negative polarity: early inflammation stage

- Positive polarity : later to facilitate epithelial cell migration across the wound bed

negative polarity→ positive polarity

9

Pulse duration

: HVPC, 40~100 ㎲

Frequency

: 60~125 pps

On:off time : off time X

Current amplitude

- sufficient to produce a comfortable sensation without a motor response

- 치료부위의 감각이 감소되거나 이상 감각이 있을 경우에는 정상 감각 부위에 먼저 electrode를 적용하여 적절한 강도 결정

Edema control 10

Edema formation associated with inflammation

: negative polarity HVPC below the threshold for motor contraction

microvessel permeability ↓

Edema formation caused by poor peripheral circulation due to lack of motion

: motor level ES

elevation, compression garment 함께 사용하면 효과적

Parameter for ES for edema control 11

ES for edema associated with inflammation

ES for edema associated with lack of muscle contraction

Iontophoresis12

transdermal drug delivery를 촉진하기 위해 low-amplitude DC 사용: mechanism ?

Depth of drug delivery : uncertain, 3~20mm - salicyclic acid와 lidocain은 stratum corneum(표피 각질층) 투과 가능

mA-min: table 8-5 , 주로 40 mA-min권장

ionized drug의 continuous delivery를 위해 DC 사용, akaline reaction: electrode 아래에서 undesirable chemical change 발생 가

능 . ! NaOH (- electrode), alkaline reaction, discomfort, skin irritation, chemical burn

→ to reduce the risk : negative electrode larger, current amplitude decrease HCl (+ electrode) : acidic reaction, less uncomfortable than alkaline reaction

Table 8-6

Parameter for the application of Iontophoresis13

Electrode placement and size - drug delivery electrode, dispersive electrode - current density가 0.5 mA(cathode), 1.0 mA(anode)를 초과하지 않도록 충분히 커

야 한다.

Polarity same polarity as the polarity of the active ion

Current amplitude : patient comfort에 의해 결정, 4mA를 넘어서는 안됨.

Treatment time - total treatment dose of 40 mA-min : table 7-7

14

Figure 08-17. 24-hour iontophoresis patch. Figure 08-18. Hybrid iontophoresis device.

15

Figure 08-20. Electrode placement for iontophoresis

Figure 08-19. The molecular structure of dexamethasone sodium phosphate.

Contraindication and precaution for the use of electrical current

Contraindication for the use of electrical currents 17

• Demand pacemaker or unstable arrhythmias

• Over the carotid sinus

• Venous or arterial thrombophlebitis

• Pelvis, abdomen, trunk, and low back area during pregnancy

Precautions for the use of electrical currents 18

Cardiac disease

Impairment mentation or impaired sensation

Malignant tumor

Skin irritation or open wounds

Iontoporesis after another physical agent

Adverse effects of electrical current 19

Careful evaluation으로 adverse effect 최소화

Burn at DC and AC

Skin irritation or inflammation

Pain

Patient positioningElectrode type Electrode placement

Application technique

20

Patient positioning

Area to be treated, goal of treatment, the device used 에 따라 환자자세 결정

ES for muscle strengthening midline → end of the available ROM

Positioning strap, cuff weight 활용하여 고정

Electrode type 22

Electrode most commonly used today Self-adhesive gel coating that serves as the conduction medium

disposable and flexible

gel : decrease resistance between the electrode and the skin

Gel coating start to dry out → uneven current density → burn

Carbon rubber electrode more long-lasting electrode, not self-adhesive

Should be cleaned with warm, soapy water and not alcohol

Current density 와 electrode size 는 반비례 larger electrode : more comfortable than smaller ones

cannot target small area

Electrode placement 23

Electrode must lie smoothly against the skin without wrinkles or gap self adhesive electrode : maintain good contact other type : flexible bandage 필요,

Should not be placed directly over bony prominence

distance or spacing between electrodes

Document electrode placement using diagram

General instruction for ES

24

25

Figure 08-23. Treatment of upper back and neck pain with electrical stimulation.

26

Figure 08-24. A, Electrical stimulation to increase hamstring strength

27

Figure 08-24. B, Electrical stimulation to increase quadriceps strength.

General stimulations for ES 28

General term

29

Waveform

31

Continuous bidirectional flow of charged particle equal ion flow in each

direction , no pulse charge

Frequency, cycle duration

Relationship between frequency and cycle duration Frequency↑, cycle duration ↓

1000~10,000 ㎐

Alternating current 32

Medium frequency 33

AC with a frequency between 1000 and 10,000 Hz 2500 ~ 5000 Hz for clinical unit

2개의 다른 medium frequency AC 의 의해 생성된 interferential current의형태로 주로 사용

Continuous current 34

Continuous flow of charged particles without interruption of break

Continuous current Direct current(DC) : one direction

Alternating current (AC) : two direction

Interferential current 35

An alternating current with a frequency of 5000 Hz interfering with an alternating currentwith a frequency of 5100 Hz to produce an interferential current with a beat frequency of 100 Hz.

interferential current between two crossed pairs of electrodes ( 4 electrode)

Interferential current 36

More comfortable than other waveform,

Why? Low amplitude current on skin

More total current than pulsed wave form

Larger area than other waveform

많은 Animal study에서 Inflammation과 ischemia와 관련된 pain을 감소시킨다고 하였으나, 특별하게 다른 효과 없다고 나타남.

AC with medium frequency

Same form as an interferential current

But single circuit and only 2 electrode

No advantage of interferential current (lower current amplitude, large area)

Premodurated current 37

An interrupted flow of charged particle

Type

Monophasic pulsed current tissue healing and acute edema

management application

Commonly used

High voltage pulsed current(HVPC)

(= pulsed galvanic current)

Pulsed current(Pulsatile current) 38

A, Monophasic; B, biphasic pulsed currents.

Biphasic pulsed current Symmetrical :

Asymmetrical : balanced, unbalanced

Symmetrical, balanced asymmetrical biphasic current

→net chare of zero

Often little difference between symmetrical and asymmetrical BPC Symmetrical : more comfortable for

large muscle group

Asymmetrical : ″ for small muscle group

Pulsed current39

A, Symmetrical;

B, balanced asymmetrical;

C, unbalanced asymmetrical biphasic pulsed currents.

Russian protocol 40

Waveform with specific parameter intended for quadriceps muscle strengthening

Median frequency AC with 2500 Hz delivered in 50 bursts/second

(= medium frequency burst AC)

Frequency

Interphase interval(intrapulse interval)

Interpulse interval

On:off time

Phase duration

Pulse duration

Ramp up/ramp down

Rise time/decay time

Wave length

Time-dependent parameter

41

Frequency 42

Number of cycles or pulsed per second

Measurement unit Hertz(Hz) for cycle

Pulse per second(PPS) for pulse

Monophasic pulsed current with frequencies of 3 pps and 9 pps.

Interval

The time between phases of a pulse

Interphase interval for a biphasic pulsed current

The time between pulse

43

Interphase interval (intrapulse interval) Interpulse interval

On: off time 44

On time: time during which a train of pulses occurs

off time: time between trains of pulses when no current flows

Usually only used when ES is used to muscle contraction

On time, off time One time: muscle contraction

off time : muscle relaxation,

needed to reduce muscle fatigue during stimulation session

Sequential on and off time

to mimic the voluntary contraction and relaxation phases of normal physiological exercise

On : off ratio

10sec on : 50 sec off

→ 1:5 on off ratio

On:off times for a biphasic current

Duration

Duration of one phase of a pulse

㎲, ㎳

Time from the beginning of the first phase of a pulse to the end of the last phase of a pulse

㎲

45

Phase duration Pulse duration

Time

During the on time During any one phase

46

Ramp up / ramp down time Rise time/decay time

Wavelength 47

The duration of 1 cycles of AC

The wavelength of AC is similar to the pulse duration of pulsed current

Amplitude (intensity)Amplitude modulation Burst modeFrequency modulationModulation Phase duration or pulse duration modulation Scan Sweep

Other ES parameter

48

Amplitude (intensity)

The magnitude of current or voltage

Modulation50

Burst mode 51

A current composed of series pulsed delivered in groups known as burst

Used to limit neural adaptationto an electrical current

Type Amplitude modulation

Frequency modulation

Phase duration /pulse duration modulation

Scan : amplitude modulation of an interferential current

Sweep: frequency modulation of an interferential current

Modulation 52

Absolute refractory periodAccommodation Action potential Adaptation ChronaxieDepolarization MyelinNode of RanvierPropagation Relative refractory current

Nerve and electrical current

53

54

Unn Figure 08-01. Unn. Fig. 8-1.

55

Medium frequency

Continuous current Direct current

Alternating current

Interferential premodulated current

Russian protocole