WAVE FORM IDENTIFICATION - G. J. Herbisongjherbison.com/pdfs/herbison-wave_form_analysis_handout.pdf · wave form identification. 3 muscle fiber & motor unit potentials g. j. herbison,

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WAVE FORM IDENTIFICATIONPURPOSE > DESCRIBE: COMMON SPONTANEOUS POTENTIALS NORMAL AND ABNORMAL RECRUITMENT PATTERNS LESS COMMON POTENTIALS

G. J. HERBISON, M.D., THOMAS JEFFERSON UNIVERSITY, PHILADELPHIA, PA 2009

MUSCLE FIBER vsMOTOR UNIT

SPONTANEOUS vs VOLITIONAL

< 5 msMove needle >disappears

> 5 msMove needle >does notdisappear

Slightly randomlyirregular

DURATIONAMPLITUDERATERHYTHM

BASED ON:

QUESTION 1. IDENTIFY POTENTIALS

a. POLYPHASIC MOTOR UNIT POTENTIALSb. NORMAL INSERTIONAL ACTIVITYc. INCREASED INSERTIONAL ACTIVITYd. DECREASED INSERTIONAL ACTIVITYe. MYOKYMIC POTENTIALS


2

QUESTION 2. THESE POTENTIALS ARE RECORDED FROMa. FIBROTIC MUSCLEb. NEONATAL MUSCLEc. MUSCLE DISUSEd. NORMAL ADULT MUSCLEe. STEROID MYOPATHY


ID INITIAL DEFLECTIONDUR DURATIONAMP AMPLITUDERA RATERHY RHYTHMO* ORIGINDS* DIAGNOSTIC SIGNIFICANCE


* In notes but will not be mentioned during presentation to allow time for adequate wave form identification

MUSCLE FIBERvs MOTOR UNIT

SPONTANEOUSvs VOLITIONAL

WAVE FORM IDENTIFICATION

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MUSCLE FIBER & MOTOR UNIT POTENTIALS


POTENTIALS are MORE LIKELY MUSCLEFIBER POTENTIALS if they ARE:

< 5 ms< 200 µvIf the POTENTIAL DISAPPEARSWITH MOVE NEEDLE MOVEMENT

POTENTIALS are MORE LIKELY MOTOR UNITPOTENTIALS if they ARE:

> 5 ms> 1 mvIf the POTENTIAL IS UNCHANBGEDWITH MOVE NEEDLE MOVEMENT

POTENTIALS ARE VOUNTARY if THEY ARESLIGHTLY RANDOMLY IRREGULAR

DETERMINING RATE =POTENTIALS/sec

EXAMPLE

100 ms BETWEEN POTENTIALS (P) =100 ms INTERPOTENTIAL INTERVAL =100 ms INTERSPIKE INTERVAL

1P100ms 1000ms/sec

X=

X = 1P x 1000ms/sec100ms

X = 10 P/secG. J. HERBISON, M.D., THOMAS JEFFERSON UNIVERSITY, PHILADELPHIA, PA 2005

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DETERMINING RATETO DETERMINE RATE i.e. Hz i.e. POTENTIALS/sec

IDENTIFY ms BETWEEN POTENTIALS =ONE POTENTIAL PER SO MANY ms =INTERPOTENTIAL INTERVAL in ms =INTERSPIKE INTERVAL in ms =INTER-EVENT INTERVAL in ms

POTENTIALS/sec 1000INTERPOTENTIAL INTERVAL in ms=


RHYTHM


Q3

a. Vol MUP

b. FIB

5

SPONTANEOUS POTENTIALSMUSCLE FIBER POTENTIALS

NORMAL ENDPLATE ACTIVITYNON-PROPAGATED: MEPP’sPROPAGATED ENDPLATE SPIKES

ABNORMAL POTENTIALSFIBRILLATIONSPOSITIVE SHARP WAVESMYOTONIACRD’s

MOTOR UNIT POTENTIALSMYOKYMIAFASCICULATIONS


MEMBRANEINSTABILITY

ALL THESEPOTENTIALSDRIFT

ID: NEGATIVEDUR: 0.2 to 2 msecAMP: 10 to 40 µVRA: 150 HzRHY: IRREGULARO: PREJUNCTIONALDS: NORMAL

MEPP


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Q4: QUESTION 3. IDENTIFY POTENTIALS

a. FIBRILLATIONSb. MYOPATHIC MUP’sc. MUP’s from EYE MUSCLESd. NEONATAL MUP’se. ENDPLATE SPIKES (EPS’s)


ENDPLATE SPIKES ID: USUALLY NEGATIVE DUR: < 5 msec AMP: < 1 mV RA: 1 to 100 Hz RHY: “WILDLY” IRREGULAR O: PREJUNCTIONAL DS: NORMAL


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a. FIBRILLATIONSb. ENDPLATE SPIKESc. MUPs


Q5

+_

+_

MUSCLE FIBER

NEEDLE ELECTRODE

NERVE

DEPOLARIZATION BEGINS AT THENEUROMUSCULAR JUNCTION (NMJ)

CLASSIC ENDPLATE SPIKE (EPS) WITH AN INITIAL NEGATIVE DEFLECTION & BIPHASIC SHAPE

CONDUCTIONPROPAGATESAWAY FROMTHE NMJ

AN EPS THAT ORIGINATES UNDER THE TIP OF THE ELECTRODE HAS AN INITIAL NEGATIVE DEFLECTION AND HAS A CLASSIC BIPHASIC SHAPE

+_ +__+

_+

+__+


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+_

+_

+_

ENDPLATE SPIKE (EPS) WITH AN INITIAL POSITIVE DEFLECTION & TRIPHASIC SHAPE

DEPOLARIZATION BEGINS AT THENEUROMUSCULARJUNCTION (NMJ)BUT AWAY FROM TIP OF THERECORDING ELECTRODE

AN EPS THAT ORIGINATES AWAY FROMTHE TIP OF THE ELECTRODE HAS AN INITIAL POSITIVE DEFLECTION

AS CONDUCTION PROPAGATESUNDER THE ELECTRODE THEDEFLECTION BECOMES NEGATIVE

AS CONDUCTION PROPAGATESAWAY FROM THE ELECTRODE THE DEFLECTION BECOMES POSITIVE

NERVENEEDLE ELECTRODE

MUSCLE FIBER

+_ _+

+__+

+_ _+

+_


+_

+_

+_

ENDPLATE SPIKE (EPS) WITH AN INITIAL POSITIVE DEFLECTION & “POSITIVE WAVE” SHAPE

DEPOLARIZATIONBEGINS AT THENEUROMUSCULARJUNCTION (NMJ)BUT AWAY FROMTIP OF THERECORDINGELECTRODE

NEEDLE ELECTRODE NERVE

MUSCLE FIBER

AS CONDUCTION PROPAGATESTOWARD THE ELECTRODE THEELECTRICAL ACTIVITYREVERSES POLARITY

AN EPS THAT ORIGINATES AWAY FROMTHE TIP OF THE ELECTRODE HAS AN INITIAL POSITIVE DEFLECTION

CONDUCTIONBLOCK

CONDUCTION DOES NOTPROPAGATE THROUGHBLOCKED AREA OF THEMUSCLE FIBER, & THENEGATIVE SPIKE (see dotted lines to the R)is not generated REPOLARIZATION OF

PREVIOUSLY DEPOLARIZEDMUSCLE FIBER

_+

+_

+_ +_


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Q6. QUESTION 4. IDENTIFY POTENTIALS

a. ENDPLATE SPIKESb. FIBRILLATIONSc. NORMAL MUP’sd. PACEMAKER POTENTIALSe. FASCICULATIONS


ID USUALLY POSITIVEDUR < 5 msecAMP < 1 mV

early > 300 µV late < 25 µV

RA 0.5 to 20 HzRHY VERY REGULAR but

DRIFT SLOW to FASTER SLOW to SLOWER EARLY SLIGHTLY IRREGULAR

O POSTJUNCTIONALDS ABNORMAL

FIBRILLATIONS IDENTIFIED BY THE SAME LETTER REPRESENTREPEAT FIRING OF THE SAME FIBRILLATION. NOTE REGULARITY OFFIRING OF THE SAME FIBRILLATIONS

A A A A A

B C B C B C B C B C


FIBRILLATION POTENTIALS

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IRREGULAR FIBRILLATION POTENTIALS

a. Voluntary MUPsb. ENDPLATE SPIKESc. FIBRILLATIONS


Q7

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G. J. HERBISON, M.D. THOMAS JEFFERSON UNIVERSITY PHILADELPHIA, PA 2009

a. FIBsb. Vol MUPs

Q8


CLOSE CLIP

a. END PLATE SPIKEb. FIBRILLATIONc. PACEMAKERd. Voluntary MUP

Q9

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QUESTION 5.IDENTIFY POTENTIALS

a. DISTANT MUP’sb. POTENTIALS from TENDONSc. POSITIVE WAVESd. ARTIFACTS from LIGHTSe. MYOTONIC POTENTIALS


POSITIVE WAVES

ID: SHARP POSITIVEDUR: 5 to 150 msecAMP: < 1 mVRA: 1 to 20 HzRHY: REGULAR but DRIFT

SLOW to FASTERALOW to SLOWER

O: POSTJUNCTIONALDS: ABNORMAL


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NEEDLE ELECTRODE

MUSCLE FIBER

MUSCLE MEMBRANEIRRITATED. Conductionbegins at the edge of theirritated membrane, notunder the tip of the needle


NEEDLE ELECTRODE

MUSCLE FIBER

MUSCLE MEMBRANE IRRITATED.Depolarization (conduction) doesnot pass the irritated segment ofmuscle membrane

DEPOLARIZATION


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INSERTIONALACTIVITY

50uV

10ms


Q11: WHAT ISTHE POTENTIALBETWEEN THETWO BURSTSOF INSERTIONALACTIVITY?

a. POSITIVE WAVEb. Voluntary MUP


a. POSITIVE WAVEb. Voluntary MUPQ12

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a. VOLUNTARY MOTOR UNIT POTENTIALb. FIBRILLATION POTENTIALSc. END PLATE SPIKES

Q13

GRADING OF FIBRILLATIONS & POSITIVE WAVES

1+ PERSIST > 1sec in > 2 SITES

2+ PERSIST IN MODERATENUMBER of SITES

3+ PERSIST IN MOST SITES

4+ PERSIST IN ALL SITE


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FIBRILLATIONS & POSITIVE WAVES DENERVATION

MYOPATHIESPOLYMYOSITISDYSTROPHIESMYOTUBULAR MYOPATHYHYPERKALEMIAACID MALTASE DEFICIENCYRHABDOMYOLYSISMUSCLE TRAUMA

UPPER MOTOR NEURON DISEASESTROKEBRAIN INJURYSCI


FIBRILLATIONS & POSITIVEWAVES UNUSUAL (MYOPATHIES)

HYPOKALEMIAMcARDLESMYOTONIA CONGENITATHYROID

HYPERHYPO

HYPOPARATHYROIDMYASTHENIA

GRAVISSYNDROME


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Q14: QUESTION 6. IDENTIFY CONDITION of the MUSCLE

50uV

10ms

a. FIBROTIC b. OLD DENERVATION c. DAY OLD DENERVATED d. FOUR WEEK OLD DENERVATION e. TWO WEEK OLD DENERVATION



a. COMPLEX REPETITIVE DISCHARGES (CRD’s)

b. MYOTONIC POTENTIALS

c. POSITIVE WAVES

d. NEUROMYOTONIC DISCHARGES

e. CRAMP POTENTIALS

50uV10ms


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MYOTONIC DISCHARGES50uV

10ms

CAN LOOK LIKE “CLASSIC”: EPS FIB’s POS WAVES

RA: 20 to 100 Hz

RHY: WAX & WANE SMOOTHLY and SLOWLY in

RATE & AMPLITUDE

O: POSTJUNCTIONAL

DS: ABNORMAL



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DS:MYOTONIC DISCHARGES MYOTONIA CONGENITA (THOMSON) MYOTONIC DYSTROPHY (STEINERT) BECKER MYOTONIA: AUTOSOMAL RECESSIVE PARAMYOTONIA DERMATOMYOSITIS MUSCLE TRAUMA HYPERKALEMIA HYPERTHYROIDISM ACID MALTASE DEFICIENCY SCHWARTZ-JAMPEL



a MYOTONIC POTENTIALSb. CRD’sc. NEUROMYOTONIC DISCHARGESd. 4 + FIBRILLTIONSe. NEEDLE ARTIFACTS

©THOMAS JEFFERSON UNIVERSITY, 2002. G. J. HERBISON, M.D.

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NEUROMYOTONIC DISCHARGESSOUND HIGH PITCHED

RATE 150 TO 300 Hz

RHYTHM WAX & WANE:RAPID CHANGEIN RATE & AMP

Q17: QUESTION 9. IDENTIFY POTENTIALSa. CRD’sb. MUP’sc. MYOTONIC POTENTIALSd. MYOKYMIC POTENTIALSe. CRAMP POTENTIALS


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COMPLEX REPETITIVE DISCHARGES (CRD’S)

MULTIPHASIC DISCHARGES

RA: 1 to 100 Hz

RHY: WITHIN DISCHARGES: REGULAR but CHANGE ABRUPTLYBETWEEN DISCHARGESREGULAR but DRIFT SLOW to FASTER SLOW to SLOWERABRUPT START & STOP

O: POSTJUNCTIONAL

DS: ABNORMAL


CRD’s: EPHAPTIC CONDUCTION

ADAPTED FROM BALL RD. GENERATORS OF SPONTANEOUS POTENTIALS. AAEM COURSE. ROCHESTER MN. 2000; p27

PACEMAKER1

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7

6

5

4

3

RED BARS REPRESENTSINGLE MUSCLE FIBERS


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a. CRDb. POLYPHASIC MUPc. ARTIFACT

Q18

a. MYOTONIC DISCHARGEb. CRDQ19


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a. POLYPHASIC MUPb. CRD

G. J. HERBISON, M.D. THOMAS JEFFERSON UNIVERSITY. PHILADELPHIA, PA 2008

Q20

DS: CRD’sNORMAL

ILIOPSOASURETHRAL SPHINCTERANY MUSCLE IN ISOLATION

ABNORMALCHRONIC

ANTERIOR HORN CELL DISEASERADICULOPATHIESPERIPHERAL NEUROPATHIES

MYOPATHIESPOLYMYOSITISMDMYXEDEMASCHWARTZ-JAMPEL


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Q21: QUESTION 10. IDENTIFY POTENTIALSa. FASCICULATIONS b. VOLUNTARY MUP’sc. END PLATE SPIKES d. TREMOR POTENTIALSe. MYOKYMIC DISCHARGES


MYOKYMIC DISCHARGES:

SINGLE or MULTIPLE MUP’s make up eachdischarge or burst

RA: Within each discharge: 5-150Hz Between each discharge: 0.1-10Hz

RHY: SEMI-REGULAR Within each discharge

more irregular than Between each discharge

O: PREJUNCTIONAL

DS: NORMAL / ABNORMAL


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DS: MYOKYMIC DISCHARGESNORMALABNORMAL

FACIALMSBRAINSTEM TUMORBELLGUILLAIN-BARRE (up to 15%)

EXTREMITYRADIATION PLEXOPATHY (60% to 70%)COMPRESSION (demyelination or remyelination)

ACUTECHRONIC

GENERALIZEDTIMBER RATTLESNAKE VENOMCIDP


Q22: QUESTION 11. IDENTIFY the MOST LIKELY CONDITIONa. NORMAL MUSCLE b. POST-POLIOc. ISAAC SYNDROMEd. ENDOCRINE MYOPATHY e. RHABDOMYOLYSIS


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SPONTANEOUS SINGLE MUP’s(only 10% to 20% polys)

RA: 2/min to 2/sec

RHY: “WILDLY” IRREGULAR

O: PREJUNCTIONAL

DS: ABNORMAL:based oncompanythey keep

THE TOP PANEL IS ONE CONTINUOUS SWEEP AT1 sec PER DIVISION. THE BOTTOM DESPLAYS SINGLEFASCICULATIONS AT 5 ms PER DIVISION.


FASCICULATION POTENTIALS

DS: FASCICULATION POTENTIALSNORMAL: FATIGUEABNORMAL

LOWER MOTOR NEURON DISEASEALS (3 of 4 regions of the body)

PRIMARY MUSCULAR ATROPHYKENNEDY SYNDROME (X LINKED RECESSIVE BULBOSPINAL MUS ATROPHY)

POST POLIOROOT COMPRESSIONCONDUCTION BLOCKPERIPHERAL NEUROPATHIES

METABOLIC/TOXICTHYROTOXICOSISTETANY ( HYPOCALCEMIA; PREDILECTION for FLEXOR HAND MUSCLES and LARYNGOSPASM)

ANTICHOLINESTERASE OVERDOSE


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SPONTANEOUS POTENTIALSMUSCLE FIBER POTENTIALS

NORMAL ENDPLATE ACTIVITYNON-PROPAGATED: MEPP’sPROPAGATED ENDPLATE SPIKES

ABNORMAL POTENTIALSFIBRILLATIONSPOSITIVE SHARP WAVESMYOTONIACRD’s

MOTOR UNIT POTENTIALSMYOKYMIAFASCICULATIONS


MEMBRANEINSTABILITY

ALL THESEPOTENTIALSDRIFT – DIFFERfrom VOLUNTARYMUPs WHICHRANDOMLY VARY

RECRUITMENT PATTERN:QUALITATIVE and/or QUANTITIVE DESCRIPTION of the

SEQUENCE of APPEARANCE of the

MUP’s DURING INCREASING VOLUNTARY MUSCLE CONTRACTION

INTERFERENCE PATTERN:PATTERN of ELECTRICAL ACTIVITY RECORDED with a

NEEDLE DURING VOLUNTARY EFFORT

A FULL INTERFERENCE PATTERN IMPLIES THAT NO MUP’s CAN BECLEARLY IDENTIFIED

Modified from MUSCLE NERVE: GLOSSARY OF TERMS: SUPPLEMENT 10:2001


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RECRUITMENTFREQUENCY

FIRING RATE (Hz) of a MUPWHEN a SECOND MUPBEGINS CONTRACTING

NORMAL RECRUITMENT: FREQUENCY < 20Hz

DECREASED RECRUITMENT: FREQUENCY > 20 Hz


RECRUITMENTRATIO

FIRING RATE of the FIRSTRECRUITED MUP DIVIDED by theNUMBER of RECRUITED MUP’sNORMAL RECRUITMENT: RATIO < 10Hz

DECREASED RECRUITMENT: RATIO > 10 Hz


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RECRUITMENT NORMAL RECRUITMENT FREQUENCY: FIRING RATE (Hz) of a MUP when a 2nd MUP BEGINS CONTRACTING: NORMAL < 20

RECRUITMENT RATIO: FIRING RATE of the FIRST RECRUITED MUP DIVIDED by the NUMBER of RECRUITED MUP’s: NORMAL < 10

NEUROPATHIC MYOPATHIC

A VOLUNTARYMUP FIRES ina RANDOMLYIRREGULARPATTERN

THE TWO “A’s” ARE the SAME MUP with ABOUT 60ms INTERVAL (RATE ABOUT 16/s.B, C & D ARE DIFFERENT MUP’s. RECRUITMENT RATIO = 16/4 = 4. ALTHOUGH “B” ISTHE FIRST MUP IN THE ABOVE FIGURE, “A” WAS THE FIRST RECRUITED MUP.

B A C D A


RECRUITMENTNORMAL

NEUROPATHIC: DECREASED RECRUITMENTFREQUENCY: > 20 HzRATIO: > 10 Hz

MYOPATHIC

ABOUT 40 ms INTERVAL= RATE of ABOUT 25Hz.RECRUITMENT FREQ = 25RECRUITMENT RATIO = 12.5


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RECRUITMENTNORMAL

NEUROPATHIC MYOPATHIC

200uV10ms

EARLY RECRUITMENT OF SMALL MUP’sWITH 1/5 GRADE MUSCLE CONTRACTION


RECRUITMENTNORMALNEUROPATHIC: DECREASEDMYOPATHIC: EARLY


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LESS COMMON SPONTANEOUS MUP’s EXCESS MOTOR UNIT ACTIVITY

CRAMPS (Begin & end with twitching of the muscle)STIFF PERSON SYNDROMENEUROMYOTONIC DISCHARGES

VOLUNTARILY INITIATED MUP’sDOUBLETSTRIPLETSMULTIPLETS

TREMORPARKINSON

ESSENTIAL


a. CRAMPb. DECREASED RECRUITMENTc. CRAMP & DECREASED RECRUITMENT


Q23

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DS: CRAMPS

NORMALBENIGN NOCTURNAL CRAMPSHEAVY EXERCISE IN WARM ENVIRONMENT

ABNORMALCHRONIC NEUROGENIC ATROPHYSALT DEPLETIONHYPOKALEMIAUREMIAPREGNANCYMYXEDEMAALCOHOLDRUGS (nifedipine, clofibrate, penicillamine, etc.)

Daube JR. Muscle Nerve 1991; 14: 685 - 700

LESS COMMON SPONTANEOUS MUP’s EXCESS MOTOR UNIT ACTIVITY

CRAMPS (Begin & end with twitching of the muscle)STIFF PERSON SYNDROME (SUSTAINED INTERFERENCE)(Auger 1994)

Syndrome: Stiff prox > dist: fixed increase in lumbar lordosisSweating, tachycardia, fluctuations in BP, increased DTR’sSpares facial musclesSpasms (painful) occur:

SpontaneouslyResponse to stimuli: emotional, auditory,cutaneous,proprioceptive

Seen in patients with: Anti GAD (Glutamic Acid Decarboxylase) Antibodies

Paraneoplastic with no anti GAD antibodie Idiopathic

NEUROMYOTONIC DISCHARGES



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CONTINUOUS MUSCLE FIBER ACTIVITY WITH STIFFNESS

NEUROMYOTONIC STIFF PERSON DISCHARGES SYNDROME

SOUND HIGH PITCHED (150 TO 300 Hz) SUSTAINED INTERFERENCE

SLEEP PERSISTS ABOLISHED

GENERAL ANESTHESIA PERSISTS ABOLISHED

NERVE BLOCK VARIABLE RESPONSE ABOLISHED

CURARE ABOLISHED ABOLISHED

DIAZEPAM PERSISTS ABOLISHED

CARBAMAZEPINE (TEGRETAL) ABOLISHED PERSISTS

DILANTIN ABOLISHED PERSISTS


ONLY DIFFERENCE IS FREQUENCYBOTH SPONTANEOUS MUP ACTIVITYBOTH POSSIBLY BASED on K CHANNELOPATHY

LOWER < 150HZ HIGHER > 150HZ

ISAAC SYNDROMETRUNK & EXTREMITY STIFFNESSHYPERHYDROSISSEEN IN PATIENTS with AUTOIMMUNE DISORDERS: MG

Thymoma Hodgkins lymphoma

Lung CarcinomaPlasmacytomaAmyloid

MORVAN VARIANT of ISAAC SYNDROMETRUNK & EXTREMITY STIFFNESSHYPERHYDROSISINSOMNIAHALLUCINATIONSCONFUSION

SPINAL MUSCULAR ATROPHYFACIAL MUSCLES DURING ACUSTIC NEUROMA SURGERY

MYOKYMICDISCHARGES

NEUROMYOTONICDISCHARGES

From Gutmann L. AAEM Course: Generators of Spontaneous Activity. 2000; 31Dumitru D, et al. Electrodiagnostic Medicine. 2nd ed. Hanley & Belfus. Philadelphia. p971

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LESS COMMON SPONTANEOUS MUP’s

EXCESS MOTOR UNIT ACTIVITYCRAMPS (Begin & end with twitching of the muscle)STIFF PERSON SYNDROMENEUROMYOTONIC DISCHARGES




a. DOUBLE DISCHARGESb. MYOKYMIC DISCHARGESQ24

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LESS COMMONSPONTANEOUS MUP’s

DOUBLETS, TRIPLETS & MULTIPLETSHYPOCALCEMIA *HYPERVENTILATIONMOTOR NEURON DISEASE (infrequent)

* HYPOCALCEMIA: PREDILECTION for FLEXOR HAND MUSCLES and LARYNGOSPASM


TREMOR @ 7/secTREMOR @ 4/sec

200uV100ms


a. Improved with alcoholb. Associated with bradykinesiac. Polyphasic voluntary MUPd. Myokymic dischargese. Multiplets

Q25

200uV100ms

36

IS IT A POLYPHASIC MUP


a. YESb. NO

Q26

WAVE FORM IDENTIFICATIONPURPOSE:

DESCRIBE: COMMON SPONTANEOUS POTENTIALS NORMAL & ABNORMAL RECRUITMENT PATTERNS LESS COMMON MUP’s

BASED ON DURATION AMPLITUDE RATE RHYTHM


MUSCLE FIBER vsMOTOR UNIT

SPONTANEOUS vs VOLITIONAL

< 5 msMove needle >disappears

> 5 msMove needle >no change

Slightly randomlyirregular

Documents

WAVE FORM IDENTIFICATION - G. J. Herbisongjherbison.com/pdfs/herbison-wave_form_analysis_handout.pdf · wave form identification. 3 muscle fiber & motor unit potentials g. j. herbison,