electrode placement system for sleep

MODULE

ELECTRODE PLACEMENT SYSTEM

FOR SLEEP

ELECTRODE PLACEMENT SYSTEM FOR SLEEP

OBJECTIVES:At the end of this module the student must be able to:• Demonstrate proper measurement of EEG

electrode sites according to the International 10-20 system

• Identify proper placement of EOG electrodes• Identify proper placement of EMG electrodes• Identify proper placement of ECG electrodes

LESSON 1: EEG ELECTRODE PLACEMENT

Summary of the International 10-20 Electrode Placement in Sleep

M1 M2

EEG ELECTRODE PLACEMENT

The EEG records the electrical activity of the brain. The different brain wave activities identify the specific stage of sleep.Correct EEG electrode placement is important to ensure proper location of electrodes in relation to cortical areas so that they can be reliably and precisely maintained from individual to individual. In order to get the “exact” placement of any EEG electrode, there must always be a cross-section of two intersecting marks. The next slides will be a step by step guide on how the EEG electrodes are attached on the scalp of the patient using the International 10-20 Electrode Placement


PROCEDURE:

1. Take measuring tape and use the centimeter side. Start from the "0" mark (cm side).Measure from the Nasion (bridge of the nose) to the Inion (occipital pretuberance - if you run your finger up the back of the neck of the skull, you will encounter a depression with the ridge of the protruding inion just above it).


PROCEDURE: (cont’d)

Mark the Nasion and Inion. (As a rule of the thumb, whichever direction the numbers are facing on the measuring tape is the direction you should make your marking). Get your total (for teaching purposes, let us say it is 36 cm).



2. Mark 50% of your total (i.e. 18 cm). This is your first mark of CZ.



3. Mark 10% up from the nasion and 10% up from the inion. (i.e. 3.6 cm)This is your first mark of FPZ and OZ.

oz

FPZ



4. Mark 20% up from either the first mark of FPZ or CZ. (i.e. 7.2 cm) This will be your first mark of FZ.

FPZ



5. Measure from pre-auricular point to pre-auricular point. Have the patient open his mouth slightly. Lightly run your finger up and down just anterior to the ear; the indentation above the zygomatic notch is easily identified. Obtain your total. (i.e. 38cm)



Mark half of your total (this number should intersect with your first 50% mark). (ex. 19 cm) This is your true CZ



6. Mark 10% up from each pre-auricular point. (ex. 3.8 cm) These are your first marks of T3, and T4.



7. Measure from your first mark of T3 to your CZ and obtain your total. (ex. 15 cm) Mark half of your total. (ex. 7.5 cm)This is your first mark of C3.



8. Measure from your first mark of T4 to your CZ and obtain your total. (ex. 15 cm) Mark half of your total. (ex. 7.5 cm)This is your first mark of C4.



9. Draw a cross-section on your first mark of FPZ. This is your true FPZ mark.

FPZ



10. Encircle the measuring tape all across your 10% mark; obtaining your circumference total. (ex. 56 cm) Mark half of your total. (ex. 28 cm)This will be your true mark of OZ.

OZ



11. Mark 5% (ex. 2.8 cm) of the half to the left and right of OZ. These will be your true marks of O1 and O2 respectively.

OZ



12. Mark 5% (ex. 2.8 cm) to the left and right of FPZ. These will be your true marks of FP1 and FP2 respectively.

FPZ



13. Mark 10% further down from FP1 and FP2. (ex. 5.6 cm) These will be your marks for F7 and F8 respectively.



14. Measure from F7 to F8 and obtain your total. (ex. 32 cm)

Mark half of your total. (ex. 16 cm). Where your first mark of FZ and this second mark of FZ intersect is your true mark of FZ.



15. Measure from F7 to FZ. Obtain your total. (ex. 16 cm)

Mark half. (ex. 8 cm) This will be your first mark of F3.



16. Measure from F8 to FZ. Obtain your total. (ex. 16 cm)

Mark half. (ex. 8 cm) This will be your first mark of F4.



17. Measure 20% from FP1 to F3. (ex. 7 cm) This will be your final mark of F3.



18. Measure 20% from FP2 to F4. (ex 7 cm)This will be your final mark of F4.



19. Measure from FP1 to your first mark of C3 to your O1. Obtain your total. (ex. 28 cm)

Mark half of your total. (ex 19 cm) Where your first and second marks intersect will be your true placement of C3



20. Measure from FP2 to your first mark of C4 to your O2. Obtain your total. (ex. 28 cm)

Mark half of your total. (ex 19 cm) Where your first and second marks intersect will be your true placement of C4


OVERVIEW:

3) Measure Nasion to Inion. Get total.4) Mark 50% from the total. This is your initial mark for

CZ.5) Mark 10% up from the Nasion and Inion. Initial mark of

FPZ and OZ.6) Mark 20% from FPZ or CZ. Initial mark of FZ.7) Measure from Pre-auricular point to pre-auricular point.

Get the total. Mark 50%. Where line will intersect with initial CZ, this is the FINAL mark of CZ


OVERVIEW: (cont’d)

6) Mark 10% up from each pre-auricular point. This is your T3, T4

7) Measure from first mark of T3 to your CZ. Obtain total. Mark half. This is your first mark of C3.

8) Measure from first mark of T4 to CZ. Obtain total. Mark half. First mark of C4.

9) Draw a cross-section across FPZ. This is your FINAL FPZ mark.



10) Measure entire circumference of head, going all across 10% marks, starting from FPZ. Get total. Mark half. TRUE mark of OZ.

11) Mark 5% of the half to the left and right of OZ. These will be your TRUE marks of O1 and O2.

12) Mark 5% of the half to the left and right of FPZ. True marks of FP1 and FP2.

13) Mark 10% further down from FP1 and FP2. Your marks for F7 and F8.



14) Measure from F7 to F8 and obtain your total. Mark half. Where your first and second marks of FZ intersect is your FINAL mark of FZ.

15) Measure from F7 to FZ. Obtain total. Mark half. This will be your first mark of F3.

16) Measure from F8 to FZ. Obtain total. Mark half. First mark of F4.

17) Measure 20% from FP1 to F3. This will be your final mark of F3.



18) Measure 20% from FP2 to F4. Final mark of F4.19) Measure from FP1 to first mark of C3 to O1. Obtain

total. Mark half. Where your first and second marks intersect will be your TRUE C3.

20) Measure from FP2 to first mark of C4 to O2. Obtain total. Mark half. Where first and second marks intersect will be your true placement of C4.


This concludes the “Modified” 10-20 Electrode Placement System for Sleep.

Next is the proper placement of EOG electrodes.

EOG ELECTRODE PLACEMENT

Electrodes are placed on each eye to determine electrical activity caused by eye movements

PROCEDURE:

On the Right, the EOG electrode is placed on the upper- outer edge of the right eye. (usually 1cm out and 1 cm up from the outer canthus of the eye)


PROCEDURE:

On the Left, the EOG electrode is placed on the lower-outer edge of the left eye. (usually 1cm out and 1 cm down from the outer canthus of the eye) Both are referenced to the contralateral mastoid site (M1, M2)


This concludes the proper placement of Right and Left EOG electrodes.

Next is the proper placement of the Chin, Leg & Arm EMG electrodes.

EMG ELECTRODE PLACEMENT

The EMG records the electrical activity of the muscles on the chin as the face twitches, the teeth grinds and the muscle relaxes on REM sleep. Electrodes are also placed on the limb, such as leg and/or arm, to monitor excessive amount of movements during sleep.


PROCEDURE:

The Chin EMG electrode is placed on the mentalis and submentalis muscle

Mentalis Submentalis



• The Leg EMG electrode is placed on the anterior tibialis muscle, 2-4 cm apart vertically.To locate the anterior tibialis muscle, palpate the shin as the patient repetitively points and flexes the foot or toes. The optimal electrode placement area is below the knee, anywhere from midpoint of the shinbone to the outer area of the upper shin.

Anterior Tibialis



• The Arm EMG electrode is placed on the forearm on the extensor digitorum muscle. To locate it, have the patient extend the forearm with palm downward. Then, feel the upper surface of the forearm as the patient bends the wrist up and down.


This concludes the proper placement of EMG electrode on the chin, leg and arm.

Next is the proper placement of ECG electrodes

ECG ELECTRODE PLACEMENT

ECG records the electrical activity of the heart, such as the rate and the rhythm.

PROCEDURE:

• Electrodes are placed just beneath the right clavicle (collar bone) and at the midclavicular line on the left (slightly lower than the right) and the fifth intercostal space

5th intercostalspace

clavicle

Mid-clavicular line (left)

RightECG placement

ECG ELECTRODE PLACEMENT

This concludes the ECG placement

ELECTRODE PLACEMENT SYSTEM FOR SLEEP

On this module you have learned to identify the proper placement of the:EEGEOGEMG and ECG leads

electrode placement system for sleep

Documents

contd mark half

mark of fpz

mark of cz

mark of c3

mark of t3

mark of t4

mark of c4

eeg electrodes