Funktionelle Elektrostimulation

8/8/2019 Funktionelle Elektrostimulation

1/45

Winfried Mayr, MedUni Wien 1

Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics

1

Center of Biomedical Engineering and PhysicsMedical University of Vienna, Austria


2

Technological Ressources

Mechanics

Microelectronics

CAD/CAM

Plastics Lab.

Electronics

Computer / Microcomputer

Ph.D.Modeling/Simulation

Digital SignalProcessing

+PC-Measurement,

CAD

Sensor-/Actuator-applications

+Sensors/

Measurement

FES-DDM

+Co-operations

Mechanics

FES-Implants

+Electronics

FES-Walking

+PCs, Network,

-Computer

PrecisionMechanics

MechanicalEngineer

CAD/CAM

Mechanic Electrical EngineerMicroelectronics

CAD/CAM

SoftwareEngineer

Ph.D.EMG-Feedback-FES

Industry collaboration

OUR TEAM Permanent Staff, Biomedical Engineering

Temporary StaffUniversity Education:

Sub-UniversityEducation:


2/45



4

CoCo--operationoperation partnerspartners

ClinicsClinics & Departments,& Departments,ViennaVienna MedicalMedical Univ.Univ.

TUTU BiomedBiomed

externalexternal ClinicsClinics,,Departments &Departments & RehabRehabCenters:Centers:WilhelminenspitalWilhelminenspitalViennaVienna, University of, University ofGraz, Weier Hof A,Graz, Weier Hof A,BadBad HringHring A, BadA, BadMurnau D, BadMurnau D, BadWildungenWildungen D, Hamburg,D, Hamburg,Tbingen, Heidelberg,Tbingen, Heidelberg,PadovaPadova, Ljubljana,, Ljubljana,MoscowMoscow, Liverpool, . . ., Liverpool, . . .

. . . . .. . . . .

Industriekooperationen:Industriekooperationen: Otto BockOtto Bock

MedMed--ElEl

InsightInsight InstrumentsInstruments

SeibersdorfSeibersdorf

Przisionsteile GmbHPrzisionsteile GmbH

PlanseePlansee

SchottSchott

. . . . .. . . . .


5

Examples for co-operations projects:

EOG forremote control

diagnosticERG

Tool for gainingbrain samples

Pruritometer

Heater forlocal hyperdermia

Force distribution measurement

knee joint endo-prostheses


6

ISEK 2006ISEK 2006 -- TorinoTorino

From Research to Clinical PracticeFrom Research to Clinical Practice

FFunctionalunctional EElectricallectrical SStimulationtimulation

Basic Research:Basic Research:-- indispensable for clinical applicationindispensable for clinical application-- explanation of clinical observationsexplanation of clinical observations

Clinical Research:Clinical Research:-- part of Clinical Practicepart of Clinical Practice

Clinical PracticeClinical Practice --> Clinical Routine> Clinical Routine-- routine component in rehabilitationroutine component in rehabilitation


3/45



7

CardiacPacemaker: First Prototyp 1958 the most successful FES-Product today


8

Auditory prostheses:

Cochlea implants

Visual prostheses:

epiretinal

subretinal optic nerve

cortical


9

Practicallyall FES-applications are based onNERVE- and NOT on MUSCLE stimulation !


4/45


5/45



13

Vienna epineural elektrode

Biocompatibility

Electrochemical stability

Mechanical stability


14

Electrode technology


15

RulesRules forfor constructingconstructing activeactive implantsimplants

AllAll surfacessurfaces biomaterialsbiomaterials,, smoothlysmoothly

structuredstructured, no, no edgesedges

RobustRobust butbut lightweightlightweight

ComponentsComponents andand DCDC--conductingconducting leadsleads inin

hermetichermetic casecase (metal oder(metal oder ceramicsceramics))

Pure metals, noPure metals, no alloysalloys

PreferablyPreferably weldingwelding,, ifif unavoidableunavoidable acidacid--

freefree solderingsoldering,, nevernever conductiveconductive bondingbonding

AntennaAntenna coilscoils insideinside thethe casecase

LongLong isolationisolation distancesdistances

PolymerPolymer sealingsealing inin NitrogenNitrogen atmosphereatmosphere,,

avoidingavoiding bubblesbubbles and fastand fast temperaturetemperature

changeschanges duringduring curingcuring

. . . . .. . . . .


6/45



16

Rf-powered8-channel implant Rf-powered20-channel implant bat terypowered 8-channel implant

3 Generations of Vienna FES-Implants


17

Antenna coil

Amplitude-limiter

P ow er su pp ly D ec od er

Impulseg enerator

Current source

Outputswitcharray

DCdecoupling capacitors

Hysol

Electrodeconn ector

8stimulation electrodes

RF-link

Antennacoil

Rechargable battery

Di sp la y C on tr ol s wi tc he s

-controllerboard

External supplyandcontrol unit

Implant

Covar case

RF-link

Antennacoil

toaSECONDIMPLANT

Stimulus Duration

PhaseChange

high,40 sm

l ow ,5 sm

CarrierSuppression,5 sm

27MHz Carrier

24 bit Data

Antennacoil

Telemetry circuit

W G 8602 bat t ery -contro ll er

Chargepumpe

Current source

Output switcharray

DC decouplingcapacitors

Hysol

Electrode connector

8stimulation electrodes

Interfacebox

Antennacoil

ImplantTitanium case

RS232

RF datalink

Electrodeconnector

Recording

electrodes

Amplifier

Rf-powered 8-channel State-of-the-art

Battery powered 8-channel Next generation


18

Wien, 1983 Montpellier, 2000

Locomotion pacemaker

Vienna, 1983 Montpellier, 2000


7/45



19

Wien, 1983 Montpellier, 2000Montpellier, 2000


20

Vienna / Bad Wildungen, 1984

Phrenic pacemaker - enormous improvement in quality of life


21

Phrenic pacemaker - enormous improvement in quality of life

Atrotech / Finnland

Avery / US


8/45



22

Brindleys sacral anterior root stimulator bladder control

more than 2000 implantations

more than 25 years lifetime


23

What decides about the survival of an FES implant ?What decides about the survival of an FES implant ?

There should beThere should be

a needa need

a smart solutiona smart solution

technology, application, handling sufficienttechnology, application, handling sufficient

legal requirements fulfilledlegal requirements fulfilled

fast reacting supportfast reacting support

in application and in case of failurein application and in case of failure justification of costsjustification of costs

unlimited financial room to moveunlimited financial room to move

..........


24

e

a b

c

f

POTENTIAL APPLICATIONS:

Continence( Graciloplasty)

Phrenic pacing

Cardiac support (latissimus)

Hand-/ arm-neuroprosthesis

Peroneus-stimulator

Walking aid

Spinal cordstimulation

- Chronic paintherapy

- Treatment of spasticity

- Locomotion

.....


9/45



25

What is new and promising ?What is new and promising ?

2 examples of novel implant applications:2 examples of novel implant applications: Activation of movement generatorsActivation of movement generators

in the SCIin the SCI(Milan(Milan DimitrijevicDimitrijevic))

Release of insulin via stimulation of theRelease of insulin via stimulation of theautonomic nervous systemautonomic nervous system((JanezJanez RozmanRozman))

26

FES of Spinal CordFES of Spinal Cord

Movement pattern generatorsMovement pattern generators

CPG, LLPGCPG, LLPG


27

Mimicking brain stem control of the lumbar network

spinalspinalspinalcordcordcordinjuryinjuryinjury

spinalspinal cordcord

stimulationstimulation

(SCS)(SCS)

tonicsuprasegmental

drive

intermittentphasicafferent input


10/45



28

Methods: Epidural spinal cord stimulationMethods: Epidural spinal cord stimulation

Continuous stimulationContinuous stimulation210 s pulse width210 s pulse width

11 10 V10 V2.22.2 100 Hz100 Hz

Cross-section at T12 vertebral level

Posterior roots

Dura mater

Epidural space

Spinal cord

Anterior roots

Vertebral bone Vertebral canal

Epidural electrode site

Electrode

Spine

Spinal cord

Pulse generator


29

NonNon--patternedpatterned spinalspinal cordcord stimulationstimulation inducesinduces steppingstepping movementsmovements

Electromyographic recording

Electrode

Spine

Spinal cord

Descendinginput

Completespinal cord injury


30

2 mV

1 mV

1 mV

1 mV

2 s

Q

H

TA

TS

KM

2 mV

Stimulus artifacts 0.05 s

0.5 mV

0.5 mV

1.5 mV

0.5 mV

45

2 s

Q

1 mV

1.5 mV

1 mV

1.5 mV

45

Q

H

TA

TS

KJA

2 s

A

B

10 V, 6 Hz 10 V, 31 Hz

90

9 V, 30 Hz


11/45



31

CanCan thethe LLPGLLPG processprocess sensorysensory feedbackfeedback inputinput toto generategeneratefunctionalfunctional EMGEMG patternspatterns?? MethodsMethods


32

CanCan thethe LLPGLLPG processprocess sensorysensory feedbackfeedback inputinput toto generategeneratefunctionalfunctional EMGEMG patternspatterns?? ResultsResults

33

FES of Autonomic Nervous SystemFES of Autonomic Nervous System

Insulin deliveryInsulin delivery


12/45



34

Experiments in dogs:

39-electrode cuffaround left vagus

biphasic rectangular:

200s, 1mA, 20Hz

increase of insulin releasein bothintact and partlydysfunctioned (alloxan)pancreas


35


36

P-system

(HC16)

stimulationmodule 1

stimulationmodule 2

stimulationmodul 3

stimulationmodule 4

I2C bus

EMG-signals

COM-Port

surface electrodes

I2C bus

4 channel

surface

stimulator

AD-board

PC

I2C Interface

stimulationmodule 1

stimulationmodule2

stimulationmodul 3

stimulationmodule4

I2C bus

EMG-signals

surface electrodes

I2C bus

APPLICATIONS:

Leg neural prosthesis

Peroneus stimulator

Remobilisation

Continence therapy

Pain therapy

Therapy of spasticity

Muscle training in space

Long-term bed rest

Chronic heart insufficiency

Sports

..


13/45



37


38

Technical WP 3Technical WP 3

stimulationmodule1

stimulationmodule2

stimulationmodul 3

stimulationmodule4

stimulationmodule1

stimulationmodule2

stimulationmodul 3

stimulationmodule4

I2C

Control Unit

RS232

RS232

433MHzFM

RS232

I2C Interface

WirelessLAN


39

EMG-triggerte FES-training

Relearning of lost movement functionsafter partial lesions

University Clinic for Physical Medicine

and Rehabilitation, MUW

University Clinic for Neurology, AKH

Rehabilitationscenters Weier Hof and

Werner Wicker-Klinik, Bad W ildungenStiwell / Medel/ Otto Bock


14/45



40

Long-term space flights are associated withdegenerative changes in the neuromuscular system.

Conventional exercising (treadmill, bicycle, expander...) at least 3-4 h per day required to be efficient.

Problems: loss of working time, motivation


41

Alternative FES training: MYOSTIMisometric muscle training with low intensity,6h per day, during routine work

easy to handle equipment:- electrode trousers (Patent D. Rafolt)- automized 8- channel stimulator

in co- operation withIBMP Moscow

First time in history application of FESfor muscle training in space

Dec.98 Feb.99 und Feb.99 Aug.99


42

Very positive judgement by both cosmonauts

Clear improvements in the functional tests:

Test 108, Ergometric locomotion

Equitest, sensomotoric coordination

Indications of positive effects of FES trainingin the neuromuscular tests:

Tendometry

Dynamometry

Reflex test

Histological results, to interprete with reservation:

Biopsyvom Vastus Lateralis

No in relation to FES interpretable results:

Bone density measurements


15/45



43

Preparation of potential application onboard ISS

ISS

Participation in the internationalterrestrialisolationstudy inMoscow(4 subjects)

successfulapplicationof themethod inchronicheart insufficiencypatients

Co- operation:University clinicfr Physical Medicineand Rehabilitation, Vienna

Terrestrial application:

French- russian crewan onboard of MIR

23. March2001


44

NMES-Group (n=17)

Age: 59 6

BMI: 22,7 3,2

LVEF: 15,1 3,1

NHYA: II: 4

III: 10

IV: 3

since, weeks: 24 6

Control group (n=16)

Age: 57 8

BMI: 25,7 3,9

LVEF: 18,1 5,2

NHYA: II: 4

III: 9

IV: 3

since, weeks: 26 5

all on a waiting list for HTX

stable medication

voluntary training not possible


45

biphasic rectangular impulsesCV / 0,7ms / 50Hz

2 s on / 6 s off

Intensity: 25 - 30% MVC

initially 30 min / day

after 2 weeks increased to 60 min / day

entire FES training period: 8 weeks

FES training parameters


16/45



46

Force-Endurance-Test

Stimulation group

150

170

190

210

230

250

270

290

310

0 5 10 15 20

Minutes

Extension

force

(N)

before

after

*

*

* * *

Control group

150

170

190

210

230

250

270

290

310

0 5 10 15 20

Minutes

Extension

force

(N)

before

after


47

NYHANMES-group

8 patients + 1 class

3: IV auf III

5: III auf II

9 patients unchanged

Control group

1 patient + 1 class

1: IV auf III

15 patients unchanged

ADL

10

12

14

16

18

20

22

NMES Control

SCOREpre

postP


17/45



49


50


51

Population pyramids 1950/2000/2050

male female

0

85year

0

85year

0

85year


18/45


52

FES ofFES ofDenervatedDenervated MusclesMuscles

Direct muscle stimulationDirect muscle stimulation


53

Uppermotor neuron lesion

Lowermotor neuron lesion

Nerve stimulation Muscle stimulation


54

Stimulation parameterStimulation parameter surface electrodessurface electrodesNerve stimulation:Nerve stimulation: Amplitude rangeAmplitude range100V /100V /300mA300mA

Pulse width (biphasic)Pulse width (biphasic)typtyp. 0.5. 0.5ms perms per phasephase

FrequencyFrequency ((fusedfused contrcontr.).)25 Hz25 Hz

Muscle stimulation:Muscle stimulation:

Amplitude rangeAmplitude range100V /100V /300mA300mA

Pulse width (biphasic)Pulse width (biphasic)typtyp.. 20ms (20ms (100ms) per100ms) per phasephase

FrequencyFrequency ((fusedfused contrcontr.).)25 Hz25 Hz


19/45



55


56


57


20/45



58

Lomo 1985


59

Valencic et. al. 1985


60

Modulation/demodulation

P ow er s up pl y -c on tr ol le r

Current source

Output endstage,

channelselector

Hysol

Electrode connector

Antennacoil

Implant

RS232

RF

datalink

Electrodeconnector

EMGrecordingelectrodes

Amplifier

External supplyand control unit

Rechargablebattery

Control switchesDisplay

-controller board

RF

powerlink

Titanium case

Dual-channelstimulationelectrodes

Antenna

connector

DC decoupling capacitors

FES of the denervatedposterior cricoarytenoid musclefor glottis opening

in synchrony with inspiration


21/45



61

Clinical program for FESClinical program for FES

of subjects with lowerof subjects with lower

motor neuron lesionmotor neuron lesion


62

5th Framework programme

Quality of Life and Management of Living Resources

Research relating to persons with disabilities

R I S E

Use of electrical stimulation to restore standingin paraplegics with long-term

denervated degenerated muscles (DDM)


63

3 cm


22/45



64

per million EU citizens yearly:

100 new spinal cord injuries 250 rehospitalisations

500 outpatient treatments

63 % paraplegics

about 1/3 flaccid paraplegia


65

no adequate rehabilitation method available

fast degeneration of muscles, skeleton, joints, skin, ...

frequent secondary diseases

problems with social and professional integration


66

Objectives of RISE

New rehabilitation methode -- transfer to clinical practice

Technical equipment -- new product family for biomedical industry

Adaptation of EU-regulations for FES-devices -- scientific basis


23/45



67

Mayr, Vienna (Co-ordinator)

Kern, ViennaSalmons, LiverpoolGirsch, ViennaCarraro, Padova

Gruber, ViennaDimitrijevic, LjubljanaGerner, HeidelbergExner, HamburgKaps, Tbingen

[Cerrel-Bazo, Vicenca][Helgason, Iceland][Protasi, Chieti]

Schrei, KlosterneuburgJonas, Bad HringPotulski, MurnauSchmidt, ViennaLosert, ViennaGallasch, Graz

Consortium:

Subcontract: Rehabilitation CentreRehabilitation CentreRehabilitation CentreDermatologyAnimal DepartmentMuscle Function

Biomedical Engineering

Clinical StudyRabbit StudyPig StudyMuscle Regeneration

Muscle HistologyNeurologyRehabilitation ClinicRehabilitation ClinicRehabilitation Clinic

Rehabilitation ClinicRehabilitation ClinicMuscle Fibre Structure

additional:


68


69

RISE Project Start Nov. 1, 2001

Kick Off Meeting Jan. 2002 in Vienna


24/45



70

100 ms

Twitch reaction

Amplitude Fmax

Duration at 50% Fmax

0

50

100

150

0 20 40 60

Pulse width [ms]

[ms]

Time to peak

00,10,20,30,40,50,60,70,8

0 20 40 60

Pulse width [ms]

[N]

Amplitude Fmax

I x t = const.

Pilot Study on Rabbits


71

Rabbit Study

STIMULATOR

TRANSMITTER UNITNOTEBOOK

ELECTRODES


72

Rabbit model ofRabbit model of denervationdenervation

DenervatedDenervated ankleankle dorsiflexorsdorsiflexors 1010 -- 51 weeks (51 weeks ( 3314 years in humans)14 years in humans)

Physiological propertiesPhysiological properties ExcitabilityExcitability

Force generation and kineticsForce generation and kinetics

Fatigue resistanceFatigue resistance

Morphological propertiesMorphological properties Weight and CSAWeight and CSA

MorphologyMorphology

Fibre areasFibre areas

Fibre typesFibre types

Electron microscopyElectron microscopy


25/45



73

Conclusions: rabbit modelConclusions: rabbit model

DenervationDenervation up to 1 year produced:up to 1 year produced:

Profound muscle and individual fibre atrophyProfound muscle and individual fibre atrophy Little degeneration / regenerationLittle degeneration / regeneration

Loss inLoss in tetanictetanic force generationforce generation

Poor morphological structurePoor morphological structure

No evidence of progressive changes; stable between 10No evidence of progressive changes; stable between 10and 51 weeksand 51 weeks denervationdenervation..

Atrophy, NOT degeneration, inAtrophy, NOT degeneration, in denervateddenervated rabbit anklerabbit ankledorsiflexordorsiflexor muscles.muscles.


74

What was achievedWhat was achieved

LongLong--term rabbit model ofterm rabbit model ofdenervationdenervation establishedestablished

Selective motorSelective motor denervationdenervation avoided problems of selfavoided problems of self--harmharm

Initial plan was toInitial plan was to denervatedenervate 10, 25 or 40 days10, 25 or 40 days

By the end we hadBy the end we had denervateddenervated up to 357 days!up to 357 days!

Safe envelope for stimulation establishedSafe envelope for stimulation established

Temperature rise under electrodes less than 1 deg CTemperature rise under electrodes less than 1 deg C

No damage under electrodes (other than thickened connective tissNo damage under electrodes (other than thickened connective tissue)ue)

No damage in muscle, even with the most intensive longNo damage in muscle, even with the most intensive long--term stimulation regimesterm stimulation regimes


75

What was achieved (What was achieved (contdcontd))ExcitabilityExcitability Did not change afterDid not change after 4 d4 d

Was not improved by stimulationWas not improved by stimulation

Size and morphologySize and morphology

Stimulation restored original weight and CSA (Stimulation restored original weight and CSA (~40% normal without)~40% normal without)

Histological appearance substantially restoredHistological appearance substantially restored

Electron microscopy (not yet liaised on stimulatedElectron microscopy (not yet liaised on stimulated--denervateddenervated))

ConclusionsConclusions

Any changes in excitability are not at cel lular level, or are deAny changes in excitability are not at cellular level, or are dependent on more atrophypendent on more atrophy

or degeneration than we sawor degeneration than we saw

Changes in SR and TChanges in SR and T--system suggest loss of Esystem suggest loss of E--C couplingC coupling


26/45



76

What was achieved (What was achieved (contdcontd))TensionTension--generating capacitygenerating capacity

Stimulation increasedStimulation increased tetanic tensiontetanic tension fromfrom ~27%~27% to ~49% of normalto ~49% of normal Force recovery not commensurate with recovery in weight and CSAForce recovery not commensurate with recovery in weight and CSA

Contractile speedContractile speed

Time to peak twitch, halfTime to peak twitch, half--relaxation and speed of shortening all much slower (likerelaxation and speed of shortening all much slower (like

soleussoleus!)!)

Stimulation did not alter thisStimulation did not alter this

ConclusionsConclusions

Slowness and loss ofSlowness and loss oftetanictetanic tension could be due to loss of Etension could be due to loss of E--C couplingC coupling

Disadvantage: reduction in power available from muscleDisadvantage: reduction in power available from muscle

AAdvantage: fusion achievable at a lower frequencydvantage: fusion achievable at a lower frequency


77

What was achieved (What was achieved (contdcontd))EnduranceEndurance

Denervation increases mitochondria (NADHDenervation increases mitochondria (NADH--TR, EM)TR, EM)

But muscles, if anything, MORE susceptible to fatigueBut muscles, if anything, MORE susceptible to fatigue

Fatigue resistance NOT improved by stimulationFatigue resistance NOT improved by stimulationworse with 40 Hz patterns!worse with 40 Hz patterns!

Lack of degenerationLack of degeneration

Major difference between rabbit (motor branches) an d rat (wholeMajor difference between rabbit (motor branches) and rat (whole sciatic)sciatic)

Could be species or procedural differenceCould be species or procedural difference

Intact muscles maintain vascular pumping, may avoid damage due tIntact muscles maintain vascular pumping, may avoid damage due to venouso venous

congestioncongestion

ConclusionsConclusions Stimulation does not improve endurance; may make it worseStimulation does not improve endurance; may make it worse

Rabbit is a GOOD model of human muscle at 1Rabbit is a GOOD model of human muscle at 1--2 years post2 years post--injuryinjury

Rat may be a good model of degenerative changes at longer periodRat may be a good model of degenerative changes at longer periodss


78

Transformation of results from the rabbit studyTransformation of results from the rabbit study

Testing of patient equipmentTesting of patient equipment

Pig Study


27/45


79

surgicalsurgical modelmodel forfor chronicchronic denervationdenervation::isolatedisolated transsectiontranssection andand resectionresectionof TA and EDLof TA and EDL motormotor branchbranch

PIG MODEL


80

0

1

2

3

4

5

6

7

8

9

0 10 20 30 40 50 60 70 80 90 100 110weeks

pigs

81

TechnicalTechnical setupsetupforfor invasiveinvasive investigationinvestigation::

SurgicalSurgical exposureexposure of TA and EDLof TA and EDL

DirectDirect needleneedle EMGEMGIntramuscularIntramuscular stimulationstimulationtoto evaluateevaluateELECTROPHYSIOLOGICAL PARAMETERSELECTROPHYSIOLOGICAL PARAMETERS

BIOPSIESBIOPSIES forfor histochemicalhistochemical investigationinvestigation

PIG EXPERIMENTS


28/45


82

Weight & Handling Problems

Bodyweight:time of denervation mean 29 kgnowR 1 - 5 mean age 103 weeks 105kgR 6 - 9 mean age 76 weeks 98kg

83

PIG EXPERIMENTS

FESR2 since 29.08.05R5 since 05.12.05

84

R1 44 weeks denervated EDL

muscle 73%

fat, connective tissue 27%


29/45


85

R1 67 weeks denervated EDL

muscle 25%

fat, connective tissue 75%


86

Electrode arrangement

A... monopolar stimulation needleB... stimulation reference

C... concentric EMG-needle

A

B

C

Measurementsetup:

BenchstimulatorDAQ PC-Card with preamplifieroszilloscope


87


30/45



88

R1 EDL den

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50

Pulsbreite/ms

Amplitude/V

l i ED L 15 12 04 _4 4w l i ED L 23 02 05 _5 1w l i ED L 20 04 05 _6 7w l i ED L 08 08 05 _8 3w

83w

67w

49w51w


89

49w 51w

3V/0.1ms; D:22mmLatency: 3,6msspeed:6,1m/s

3V/0.1ms; D:22mmLatency: 3.7msspeed:5,9m/s

1-2ms 1-2ms

89w

EMG-signanot found

R1_EDL li


90

TechnicalTechnical WPsWPs WP 3: Equipment for homeWP 3: Equipment for home--based trainingbased training

WP 4: TestWP 4: Test-- and measurement equipmentand measurement equipment


31/45



91

Patient Study / Technical WP3


92

Required pulse width

initially 120 - 150 ms

after appr. 1 year 30 - 40 ms

shortest pulse width 25 - 35 ms

t

(Nerve stimulation: 0.2 2ms)

Peak amplitude

+/- 80 V +/- 250 mA


93

Technical WP 3Technical WP 3


32/45



94

Agonist

Antagonist

FES

ForceDisplacement

Tendometry

t

50 100 150 200 250 300 350 400

-0.05

0

0.05

0.1

0.15

0.2

t

F

MucleStiffness& Viscosity

no stimulatin

Withstimulation

Transversal muscle stiffness

Oscillation Tonometry

Problem ofCo-contraction

0 2 4 6 8 1 0 12 1 4 160

0.5

1

1.5

2

2.5

3

3.5

4

Force

Kontraction

Displacement

Patient Study / Technical Workpackage 4

96

a mobile and a stationary system

Oscillation Tonometry


33/45


97

no stimulation weak stimulationOscillation TonometryPiendl

0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4

1,6

1,8

2,0

0 50 60 70 80 90 99

Stimulationin %of 80V

Frequenz

Daempfung


98

LegLeg responsesresponses whilewhile FESFES amplitudeamplitude waswas increasedincreased


99

Pendulum testModeling and estimated parameters

pendulumtestdata

model

forpendular

legmotion

T... joint torque

limb

geometricaldata

C...joint stiffness

D...viscous moment

J...moment of inertiaCG... gravity spring

sin( ) 0J D mgL C + + + =&& & sin( ) GmgL C =with


34/45


100

110 Skul

116 Ness

111 Pien

117 Lan

205 Br

206 Bt

119 Th

Oscillation TonometryFES-induced elastic moment [%]

-100

0

100

200

300

400

500

600

700

0 8 16 24 32 40 48 56 64 72 80

stimulation [V]

FES-inducedelasticmoment[%]

109-7.7y

105-7.5y

301-6.5 y

112-6.2y

117-6.2y

206-5.5y

104-4.1y

106-3.5y

108-3.3y

119-3.3y

111-1.8y

113-1.7y

207-15m

118-13m

110-11m

116-10m

114-10m

120-10m

115-10m

205-9m

201-9m

mean


101

Vergleich:Vergleich:nderung des Parameters Dnderung des Parameters D

Beispiel: Patient 7,3 Jahre denerviert

0,00

0,02

0,04

0,06

0,08

0,10

0,12

0,14

0 8 16 24 32 40 48 56 64 72 80

Stimulationsamplitude in V

nderungvonDinNms

vor demTraining

nach 1 Jahr Training

Beispiel: Patient 1,5 Jahre denerviert

0,00

0,50

1,00

1,50

2,00

2,50

0 8 16 24 32 40 48 56 64 72 80

Stimulationsamplitude in V

nderu

ngvonD

inNms

vor dem Training

nach 1 Jahr Training


102

Rot:preFES

Blau:1 Jahr FES

50 100 150 200 250 300 350 400

-0.05

0

0.05

0.1

0.15

0.2

t

F

TTP, HRT und El.Mech.Delay bei verschiedenen Pulsbreiten(1, 5, 10, 20, 40, 80, 120, 160ms)

Kein Balken bedeutet: kein Twitch detektierbarMit FES ist die Detektionsschwelle von 40ms auf 20ms gesunken.

Time to peak(TTP) Half relaxationtime (HRT) El.mech. delay


35/45



103

SingleSingle fiberfiber recordings / measurement setuprecordings / measurement setup


104

Analysis of muscle fibre conduction velocityAnalysis of muscle fibre conduction velocity(MFCV)(MFCV)

first pos. spike > 50Vfirst pos. spike > 50V

(5.76 ms)(5.76 ms)

last pos. spike (8.22 ms)last pos. spike (8.22 ms)

mean latency of all recordedmean latency of all recorded

spikes > 50V (7.10 ms)spikes > 50V (7.10 ms)

distancedistance betwbetw. electrodes. electrodes

32 mm32 mm

max. MFCVmax. MFCV = 5.6 ms= 5.6 ms--11

min. MFCVmin. MFCV = 3.9 ms= 3.9 ms--11

mean MFCV = 4.5 msmean MFCV = 4.5 ms--11


105

Double pulse stimulation ofDouble pulse stimulation of

denervateddenervated musclemuscle


36/45



106

RISE Pat. 108RISE Pat. 108 afterafter 11stst and 2and 2ndnd yearyear of FESof FES

ISI = 6 ms; MFCV = 1.85 m/s ISI = 3 ms; MFCV = 4.12 m/s


107

RISE Pat. 119RISE Pat. 119 beforebefore andand afterafter 11 yearyear of FESof FES

MFCV = 0.98 m/s; ISI = 8 ms MFCV = 1.83 m/s; ISI = 3 ms


108

CTCTscansscans everyevery 10 cm10 cm

trochanter

20 cm

10 cm

30 cm

40 cm

0 cm


37/45



109

8.7a denervatedcross sectional area = ???

1.7a dendervatedcross sectional area = 50.17 cmmean density= 30 HU

PlanimetryPlanimetry

Cross Sectional Area (cm) andDensity (HU)


110

A.B. #18 ( 205 )

0.8y denervated

20cm

30cm

CrossCross sectionsection rightrightthighthighat 20 &at 20 &

30cm30cm

0y 1y 2.5y0y 1y 2.5y stimulationstimulation


111


38/45



112

H.T. #36 ( 119 )

3.2y denervated

20cm

30cm


30cm30cm

0y 1.1y 1.6y0y 1.1y 1.6y stimulationstimulation


113


114

K.L. #24 ( 109 )

7.7y denervated

20cm

30cm


30cm30cm

0y 1.3y 2.5y0y 1.3y 2.5y stimulationstimulation


39/45



115


116

Biopsies


117

Prof. Ugo Carraro - Applied Myology Lab -Padova [email protected]

0.9-y [110 (26-5)]

1.9-y [111 (28-5)]

4.0-y [104 (20-5)]

8.7-y [103 (14-1)]

Long-term Denervated Human Muscle

Lower Motor Neuron Lesion


40/45



118

From: Kern H et al J Rehabil

Res Dev 2005

Prof. Ugo Carraro -Applied

Myology Lab -Padova

[email protected]

Long-term Lower Motor Neuron Lesion

FES Training of Denervated Human Muscle


119

Myofiber

Regeneration

in Long-term

Denervated

Human

Muscle

FES -

Training

Lower

Motor

Neuron

Lesion

MHC-emb+

RegeneratingMyofibers

From: Kern H et al J. Neuropathl Exp Neurol

2004; 63: 919-931.

Prof. Ugo Carraro -Applied Myology Lab -

Padova [email protected]


120

Effect of FES Training on Myofiber Size of


Prof. Ugo Carraro - Applied Myology Lab -Padova u [email protected] ECPRM - Wien, May 15, 2004

0

10

20

30

40

50

60

70

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Denervation (year)

MinimumDiameter(m)

FES Trained Normal Peripheral Denervation Central Lesion


41/45



121

MuscleMuscle excitabilityexcitability

CaCa++++ releaserelease

-- tttubulustubulus (1)(1)

-- sarcoplasmaticsarcoplasmatic reticulumreticulum (2)(2)

-- triadtriad (3)(3)

1

2

3


122

A, Severe atrophic fiber. B, a triad in normally innervated muscle. C-D, following long-termdenervation the frequency of ECC units decreases and the morphology changes

dramatically: Many junctions appear to be dyspedic (i.e. they lack RyRs).

1515--monthmonth DenervatedDenervated Human Quadriceps MuscleHuman Quadriceps Muscle

UgoCarraro, Applied MyologyLab, University of Padova

N

N


123

Conclusions

1. Human skeletal muscle undergoes three phases during long-term

denervation:

i) Atrophy; ii) Lipodystrophy; iii) Fibrosis,

2. Myofibers survive denervation much longer than generally accepted

(years)

3. After permanent lower-motoneuron lesion repeated cycles of myofiber

death/regeneration contribute to long-term skeletal muscle tissue

persistence

4. Regenerated myofibers have higher excitability and strength than long-

term denervated myofibers

5. Long-term FES training reverts severe denervation atrophy and

maintains trophism of regenerated myofibers

Prof. Ugo Carraro - Applied Myology Lab -Padova [email protected]


Lower Motor Neuron Lesion


42/45



124

Patient StudyPre- Clinical

selection Evaluation September 03 May 04 End of study

Wilhelminenspital 15 12 8 2 3 4

Weier Hof 13 8 5 1 2 3

Bad Hring 13 8 5 1 2 3

Murnau 13 8 5 2 5 3

Heidelberg 13 8 5 3 4 3

Hamburg 13 8 5 0 2 3

Tbingen 13 8 5 1 1 3

Vicenza 1 2

Island 2 3

Piacenza/Lotta 1 1

Patienten

gesamt

93 60 3 8 14 25 22

Begin of

study


125

PatientPatient StudyStudy

55 womenwomen 43 a43 a 5.8 a denervated5.8 a denervated

23 men

36 a

4.9 a denervated

28 Patients with traumatic fracture betweenTh5 und L1

(9 Th11, 13 Th12)

0

1

2

3

4

5

6

7

8

9

10

11

up to 1,5 2 to 5 6 to 10 11 to 20 20 +

yearsof denervation

numberofpatients


126


43/45



127


128

A B

x 40

x 4500

additional Rat Study


129

field distribution in the thigh

AP-Excitation and Propagation

Simulation of FESmuscle fiber

tubular openings

extra cellular

intra cellular

sarcomere

myofibri l lssarkolemma

transversal tubulus

longitudinal tubulus


44/45



130

ColourColour--coded T2coded T2--maps of humanmaps of humanskeletal muscle before (left) andskeletal muscle before (left) and

after (right) shortafter (right) short--term FES.term FES.


131

RISE Plenary Meeting - Iceland June 2005

End of RISE - May 31, 2006

132

9th VIENNA INTERNATIONAL WORKSHOP on

FUNCTIONAL ELECTRICAL STIMULATION

Basics, Technology, Application

19.Sept. - 22. Sept. 2007

The conference location is in one the mostlovely regions of Austria named "Wachau",

in the city of Krems/Danube

http://2007.fesworkshop.org/


45/45

Documents

Funktionelle Elektrostimulation