Download - Funktionelle Elektrostimulation
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Winfried Mayr, MedUni Wien 1
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Center of Biomedical Engineering and PhysicsMedical University of Vienna, Austria
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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:
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Winfried Mayr, MedUni Wien 2
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
. . . . .. . . . .
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Examples for co-operations projects:
EOG forremote control
diagnosticERG
Tool for gainingbrain samples
Pruritometer
Heater forlocal hyperdermia
Force distribution measurement
knee joint endo-prostheses
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
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Winfried Mayr, MedUni Wien 3
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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CardiacPacemaker: First Prototyp 1958 the most successful FES-Product today
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Auditory prostheses:
Cochlea implants
Visual prostheses:
epiretinal
subretinal optic nerve
cortical
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Practicallyall FES-applications are based onNERVE- and NOT on MUSCLE stimulation !
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Winfried Mayr, MedUni Wien 5
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Vienna epineural elektrode
Biocompatibility
Electrochemical stability
Mechanical stability
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Electrode technology
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
. . . . .. . . . .
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Winfried Mayr, MedUni Wien 6
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Rf-powered8-channel implant Rf-powered20-channel implant bat terypowered 8-channel implant
3 Generations of Vienna FES-Implants
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Wien, 1983 Montpellier, 2000
Locomotion pacemaker
Vienna, 1983 Montpellier, 2000
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Winfried Mayr, MedUni Wien 7
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Wien, 1983 Montpellier, 2000Montpellier, 2000
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Vienna / Bad Wildungen, 1984
Phrenic pacemaker - enormous improvement in quality of life
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Phrenic pacemaker - enormous improvement in quality of life
Atrotech / Finnland
Avery / US
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Winfried Mayr, MedUni Wien 8
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Brindleys sacral anterior root stimulator bladder control
more than 2000 implantations
more than 25 years lifetime
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
..........
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
.....
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Winfried Mayr, MedUni Wien 9
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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))
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FES of Spinal CordFES of Spinal Cord
Movement pattern generatorsMovement pattern generators
CPG, LLPGCPG, LLPG
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Mimicking brain stem control of the lumbar network
spinalspinalspinalcordcordcordinjuryinjuryinjury
spinalspinal cordcord
stimulationstimulation
(SCS)(SCS)
tonicsuprasegmental
drive
intermittentphasicafferent input
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Winfried Mayr, MedUni Wien 10
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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NonNon--patternedpatterned spinalspinal cordcord stimulationstimulation inducesinduces steppingstepping movementsmovements
Electromyographic recording
Electrode
Spine
Spinal cord
Descendinginput
Completespinal cord injury
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
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Winfried Mayr, MedUni Wien 11
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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CanCan thethe LLPGLLPG processprocess sensorysensory feedbackfeedback inputinput toto generategeneratefunctionalfunctional EMGEMG patternspatterns?? MethodsMethods
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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CanCan thethe LLPGLLPG processprocess sensorysensory feedbackfeedback inputinput toto generategeneratefunctionalfunctional EMGEMG patternspatterns?? ResultsResults
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FES of Autonomic Nervous SystemFES of Autonomic Nervous System
Insulin deliveryInsulin delivery
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Winfried Mayr, MedUni Wien 12
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Experiments in dogs:
39-electrode cuffaround left vagus
biphasic rectangular:
200s, 1mA, 20Hz
increase of insulin releasein bothintact and partlydysfunctioned (alloxan)pancreas
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
..
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Winfried Mayr, MedUni Wien 13
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
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Winfried Mayr, MedUni Wien 14
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
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Winfried Mayr, MedUni Wien 15
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
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Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
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Winfried Mayr, MedUni Wien 17
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Population pyramids 1950/2000/2050
male female
0
85year
0
85year
0
85year
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Winfried Mayr, MedUni Wien 18
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FES ofFES ofDenervatedDenervated MusclesMuscles
Direct muscle stimulationDirect muscle stimulation
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Uppermotor neuron lesion
Lowermotor neuron lesion
Nerve stimulation Muscle stimulation
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
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Winfried Mayr, MedUni Wien 19
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Winfried Mayr, MedUni Wien 20
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Lomo 1985
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Valencic et. al. 1985
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
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Winfried Mayr, MedUni Wien 21
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Clinical program for FESClinical program for FES
of subjects with lowerof subjects with lower
motor neuron lesionmotor neuron lesion
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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)
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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3 cm
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Winfried Mayr, MedUni Wien 22
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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per million EU citizens yearly:
100 new spinal cord injuries 250 rehospitalisations
500 outpatient treatments
63 % paraplegics
about 1/3 flaccid paraplegia
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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no adequate rehabilitation method available
fast degeneration of muscles, skeleton, joints, skin, ...
frequent secondary diseases
problems with social and professional integration
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
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Winfried Mayr, MedUni Wien 23
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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:
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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RISE Project Start Nov. 1, 2001
Kick Off Meeting Jan. 2002 in Vienna
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Winfried Mayr, MedUni Wien 24
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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Rabbit Study
STIMULATOR
TRANSMITTER UNITNOTEBOOK
ELECTRODES
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
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Winfried Mayr, MedUni Wien 25
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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.
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
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Winfried Mayr, MedUni Wien 26
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
Winfried Mayr Vienna Medical University - Center of Biomedical Engineering& Physics
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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
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Transformation of results from the rabbit studyTransformation of results from the rabbit study
Testing of patient equipmentTesting of patient equipment
Pig Study
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surgicalsurgical modelmodel forfor chronicchronic denervationdenervation::isolatedisolated transsectiontranssection andand resectionresectionof TA and EDLof TA and EDL motormotor branchbranch
PIG MODEL
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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
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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%
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R1 67 weeks denervated EDL
muscle 25%
fat, connective tissue 75%
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Electrode arrangement
A... monopolar stimulation needleB... stimulation reference
C... concentric EMG-needle
A
B
C
Measurementsetup:
BenchstimulatorDAQ PC-Card with preamplifieroszilloscope
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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
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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
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TechnicalTechnical WPsWPs WP 3: Equipment for homeWP 3: Equipment for home--based trainingbased training
WP 4: TestWP 4: Test-- and measurement equipmentand measurement equipment
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Patient Study / Technical WP3
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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
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Technical WP 3Technical WP 3
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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
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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
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LegLeg responsesresponses whilewhile FESFES amplitudeamplitude waswas increasedincreased
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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
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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
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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
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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
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SingleSingle fiberfiber recordings / measurement setuprecordings / measurement setup
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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
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Double pulse stimulation ofDouble pulse stimulation of
denervateddenervated musclemuscle
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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
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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
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CTCTscansscans everyevery 10 cm10 cm
trochanter
20 cm
10 cm
30 cm
40 cm
0 cm
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8.7a denervatedcross sectional area = ???
1.7a dendervatedcross sectional area = 50.17 cmmean density= 30 HU
PlanimetryPlanimetry
Cross Sectional Area (cm) andDensity (HU)
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A.B. #18 ( 205 )
0.8y denervated
20cm
30cm
CrossCross sectionsection rightrightthighthighat 20 &at 20 &
30cm30cm
0y 1y 2.5y0y 1y 2.5y stimulationstimulation
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H.T. #36 ( 119 )
3.2y denervated
20cm
30cm
CrossCross sectionsection rightrightthighthighat 20 &at 20 &
30cm30cm
0y 1.1y 1.6y0y 1.1y 1.6y stimulationstimulation
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K.L. #24 ( 109 )
7.7y denervated
20cm
30cm
CrossCross sectionsection rightrightthighthighat 20 &at 20 &
30cm30cm
0y 1.3y 2.5y0y 1.3y 2.5y stimulationstimulation
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Biopsies
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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
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From: Kern H et al J Rehabil
Res Dev 2005
Prof. Ugo Carraro -Applied
Myology Lab -Padova
Long-term Lower Motor Neuron Lesion
FES Training of Denervated Human Muscle
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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]
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Effect of FES Training on Myofiber Size of
Long-term Denervated Human Muscle
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
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MuscleMuscle excitabilityexcitability
CaCa++++ releaserelease
-- tttubulustubulus (1)(1)
-- sarcoplasmaticsarcoplasmatic reticulumreticulum (2)(2)
-- triadtriad (3)(3)
1
2
3
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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
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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]
Long-term Denervated Human Muscle
Lower Motor Neuron Lesion
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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
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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
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A B
x 40
x 4500
additional Rat Study
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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
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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.
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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/
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