Functional Electrical Stimulation (FES) - a re-emerging technology

Functional Electrical Functional Electrical Stimulation (FES) - Stimulation (FES) -

a re-emerging technologya re-emerging technology

Ian SwainIan Swain

Dept. of Medical Physics and Dept. of Medical Physics and Biomedical Engineering, Salisbury Biomedical Engineering, Salisbury

District Hospital, U.K. District Hospital, U.K.

Academic Biomedical Engineering Academic Biomedical Engineering Research Group, Bournemouth University,Research Group, Bournemouth University,

U.K.U.K.

What are the What are the Prerequisites for a Prerequisites for a Clinical FES ServiceClinical FES Service

Clinical demandClinical demand Evidence that the technique worksEvidence that the technique works Management, Consultant, GP/PCT and Management, Consultant, GP/PCT and

patient support - patient support - all ideally neededall ideally needed Adequate and reliable fundingAdequate and reliable funding InformationInformation Reliable equipmentReliable equipment Trained staffTrained staff

DemandDemand

118,000 new 118,000 new strokes per year in strokes per year in UK,UK,– 10,000 under 50 10,000 under 50 – 1,000 under 30 1,000 under 30

80% survival, 30% 80% survival, 30% complete recoverycomplete recovery

about 10,000 left about 10,000 left with dropped foot with dropped foot

85,000 MS in UK85,000 MS in UK CPCP Head injuryHead injury Incomplete Spinal Incomplete Spinal

cord injurycord injury

Evidence -Evidence -Randomised controlled Randomised controlled

trial of the Odstock trial of the Odstock Dropped Foot Dropped Foot

StimulatorStimulatorJane Burridge, Paul Taylor, Jane Burridge, Paul Taylor,

Ian SwainIan Swain

Salisbury District HospitalSalisbury District Hospital

StudyStudy

32 subjects who had had a Stroke 32 subjects who had had a Stroke randomly allocated to an FES and a randomly allocated to an FES and a control groupcontrol group

Each group received 10 one hour Each group received 10 one hour sessions of physiotherapy over 1 sessions of physiotherapy over 1 month. The FES group used the month. The FES group used the stimulator in the sessions and at homestimulator in the sessions and at home

Assessments at start, 1 month and Assessments at start, 1 month and three monthsthree months

AssessmentsAssessments

Walking speedWalking speed Physiological Cost Index (PCI)Physiological Cost Index (PCI) Spasticity - Watenberg pendulum drop Spasticity - Watenberg pendulum drop

testtest Mobility questionnaireMobility questionnaire Nothingham QoL Health profileNothingham QoL Health profile Hospital Anxiety and Depression indexHospital Anxiety and Depression index Use of stimulator questionnaireUse of stimulator questionnaire

Walking speed at 3 Walking speed at 3 monthsmonths

With stimulationWith stimulation 20.5%20.5% p < p < 0.010.01

No StimulationNo Stimulation 0.12%0.12% p = 1p = 1 ControlControl 5.2%5.2% p = p =

0.380.38

PCI at 3 monthsPCI at 3 months

With StimulationWith Stimulation -24.1%-24.1% p < p < 0.010.01

No stimulationNo stimulation -11.8%-11.8% p = p = 0.670.67

ControlsControls -3.9 %-3.9 % p = 0.47p = 0.47

Quadriceps SpasticityQuadriceps Spasticity

A reduction in spasticity seen in A reduction in spasticity seen in the control group after 10 sessions the control group after 10 sessions of physiotherapy. This was lost of physiotherapy. This was lost after 2 monthsafter 2 months

A reduction in spasticity in the FES A reduction in spasticity in the FES group at the third assessmentgroup at the third assessment

Hospital Anxiety and Hospital Anxiety and Depression Index (HAD)Depression Index (HAD) Treatment GroupTreatment Group

– DepressionDepression– 5.5 5.5 3.5 3.5

p = 0.0028p = 0.0028

– AnxietyAnxiety5.3 5.3 3.0 3.0p = 0.0047p = 0.0047

Control GroupControl Group

– DepressionDepression– 4.3 4.3 3.8 3.8

p = 0.441p = 0.441

– AnxietyAnxiety4.8 4.8 3.7 3.7p = 0.096p = 0.096

ConclusionsConclusions

Significant increase in walking speed in Significant increase in walking speed in FES group - no change in control groupFES group - no change in control group

Significant fall in PCI in FES group - no Significant fall in PCI in FES group - no change in the control groupchange in the control group

Reduction in spasticity in FES group onlyReduction in spasticity in FES group only Reduced HAD scoreReduced HAD score Positive cost-benefit (QALY gain of Positive cost-benefit (QALY gain of

0.042)0.042)

Patients treated in Patients treated in Salisbury Salisbury (7/04/05)(7/04/05)

Service running for eleven yearsService running for eleven years Over 2000 patients referred to the Over 2000 patients referred to the

service and seen, not including the service and seen, not including the many who have participated in clinical many who have participated in clinical trialstrials

880 CVA, 540 MS, 120 SCI, 63 CP, 25 880 CVA, 540 MS, 120 SCI, 63 CP, 25 facial, 31 TBI, plus other neurological facial, 31 TBI, plus other neurological conditionsconditions

Patient with SLE, and subsequent bilateral CVA

Changes in Walking Changes in Walking SpeedSpeedFig. 2 Median % change in walking speed for MS (n=42)and CVA (n=116)

Initial walking speed MS 0.68ms-1 and CVA 0.57ms-1

-10

-5

0

5

10

15

20

25

0 10 20 30 40 50 60 70 80

Weeks

% c

han

ge

in w

alki

ng

sp

eed

rel

ativ

e to

NS

wee

k 0

CVA S

CVA NS

MS S

MS NS

Changes in PCIChanges in PCIFig 3 Median % change in PCI MS (n=42) and CVA (n=116)

Initial PCI MS 0.56 Heartbeats/min, CVA 0.57Heartbeats/min

-25

-20

-15

-10

-5

0

5

10

15

0 10 20 30 40 50 60 70 80

Weeks

% c

ha

ng

e in

PC

I re

lati

ve

to

NS

we

ek

0

CVA S

CVA NS

MS S

MS NS

Reliable equipmentReliable equipment

MUST meet patients needsMUST meet patients needs User involvement essential to design processUser involvement essential to design process large numbers needed to trial, then modify large numbers needed to trial, then modify

design accordingly, iterative processdesign accordingly, iterative process RELIABLERELIABLE

ODFS footswitch works every time, fifteen years ODFS footswitch works every time, fifteen years development ~1-200,000 cycles, ~development ~1-200,000 cycles, ~66//1212 use use

Safe, and built to recognised standardsSafe, and built to recognised standards Quality control, e.g. ISO 9000Quality control, e.g. ISO 9000 CE markedCE marked

Equipment Currently Equipment Currently AvailableAvailable

Few practical systems available such as Few practical systems available such as the FreeHand, HandMaster, Vocair the FreeHand, HandMaster, Vocair (Brindley Bladder Stimulator), ODFS etc (Brindley Bladder Stimulator), ODFS etc

From Salisbury we can supply (to From Salisbury we can supply (to registered users)registered users)– ODFSODFS– 2 channel ODFS2 channel ODFS– 2 and 4 channel exercise stimulators2 and 4 channel exercise stimulators– consumablesconsumables– implanted dropped foot system - STIM-U-STEPimplanted dropped foot system - STIM-U-STEP

Stim-U-StepStim-U-Step

2 channel implanted stimulator 2 channel implanted stimulator – CE marked, clinical service later this yearCE marked, clinical service later this year

Deep branchDeep branch– dorsiflexion + inversiondorsiflexion + inversion

Superficial branchSuperficial branch– dorsiflexion + eversiondorsiflexion + eversion

Developed with EU funding with, Developed with EU funding with, Salford, Het Roessingh and FinetechSalford, Het Roessingh and Finetech

Stim-U-Step - Stim-U-Step - implanted peroneal implanted peroneal

nerve stimulatornerve stimulator

Stim-U-Stim-U-StepStep

Handmaster system for stroke / tetraplegics

Using Handmaster systemUsing Handmaster system

Staff TrainingStaff Training

FES equipment has a tendency to be sold FES equipment has a tendency to be sold from back pages of newspapersfrom back pages of newspapers

FES is not a treatment in itself it is a part FES is not a treatment in itself it is a part of a rehabilitation programmeof a rehabilitation programme– use with BoTox, orthotics, therapy etcuse with BoTox, orthotics, therapy etc

Only trained staff can order and fit Only trained staff can order and fit equipment.equipment.

Therefore continuous training, education Therefore continuous training, education and support neededand support needed

Patient SupportPatient Support

Clinical guidelines/ Care pathways Clinical guidelines/ Care pathways – 82%success at initial assessment82%success at initial assessment

Prompt repair servicePrompt repair service Ongoing support for staff and Ongoing support for staff and

patientspatients– 86%compliance at 1 year86%compliance at 1 year

Audit and regular questionnairesAudit and regular questionnaires

How is the ODFS used?How is the ODFS used?

StrokeStroke Use every day Use every day 48%48% Use 4-6 daysUse 4-6 days 15%15%

10 to 100 yds10 to 100 yds 38%38% 100 to 500 yds100 to 500 yds 33%33% 500 yds to 1 m500 yds to 1 m 12%12% 1 m +1 m + 8% 8%

MSMS Use every day Use every day 40% 40% Use 4-6 daysUse 4-6 days 28% 28%

10 to 100 yds*10 to 100 yds* 40% 40% 100 to 500 yds** 38%100 to 500 yds** 38% 500 yds to 1 m500 yds to 1 m 8% 8% 1 m +1 m + 5% 5%

*EDSS 6 - 6.5*EDSS 6 - 6.5

**EDSS 4 - 5.5**EDSS 4 - 5.5

Most important reasonMost important reason

StrokeStroke

Less effortLess effort 27%27% Long term hopeLong term hope 20%20% CarryoverCarryover 22%22% More confidentMore confident 10%10%

MSMS

Less effortLess effort 33%33% Trip lessTrip less 28%28% Walk furtherWalk further 10%10% More confidentMore confident 10%10% No stickNo stick 10%10%

Clinical TreatmentClinical Treatment

StrokeStroke

very goodvery good 85%85% goodgood 12%12%

MSMS

very goodvery good 75% 75% goodgood 25% 25%

Improving hand Improving hand functionfunction

ExercisesExercises Reciprocal flexion and Reciprocal flexion and

extension of the wrist and extension of the wrist and fingers, optionally with the fingers, optionally with the lumbrical muscles.lumbrical muscles.

Exercises began at two Exercises began at two periods of 15 minutes a periods of 15 minutes a day, increasing to two day, increasing to two periods of 1 hour by three periods of 1 hour by three monthsmonths

20 Hz, 300 micro Seconds, 20 Hz, 300 micro Seconds, up to 80 mA.up to 80 mA.

MeasurementsMeasurements

1.1. The Jebsen-Taylor hand The Jebsen-Taylor hand function function test.test.

2.2. Static two point discriminationStatic two point discrimination 3.3. Power, pinch and key grip Power, pinch and key grip

strengthstrength

JEBSEN-TAYLOR % CHANGE

-50

0

50

100

150

200

1 3 5 7 9 11 13 15 17 19

SUBJECTS

% C

HA

NG

E

%CHANGE

SUBJECT 1. TWO POINT FREQUENCY

0

1

2

3

4

5

6

7

8

9

10

0 1 2 3 4 5

SCORE

FR

EQ

UE

NC

Y

BEFORE

AFTER

UNAFFECTED

ConclusionsConclusions

1.1. There are statistically significant There are statistically significant improvements in static two point discrimination improvements in static two point discrimination score, Jebsen-Taylor test score and key grip strength score, Jebsen-Taylor test score and key grip strength following three months of electrical stimulation following three months of electrical stimulation exercises.exercises.

2.2. It is not clear if there are significant benefits in It is not clear if there are significant benefits in ADL, though some anecdotal evidence was reported.ADL, though some anecdotal evidence was reported.

3. There is evidence to support the use of FES in 3. There is evidence to support the use of FES in shoulder subluxation (Chae,J) and useful in shoulder subluxation (Chae,J) and useful in improving hygiene in severe spasticity.improving hygiene in severe spasticity.

The clinical service in The clinical service in SalisburySalisbury

Clinical Service 1Clinical Service 1

Dropped foot correctionDropped foot correction Bilateral dropped footBilateral dropped foot More complex movement problemsMore complex movement problems

– 2 channel stimulator2 channel stimulator– in conjunction with orthoticsin conjunction with orthotics

Upper limb functionUpper limb function Facial stimulationFacial stimulation OrthopaedicOrthopaedic

Clinical Service 2 Clinical Service 2 (07/04/05)(07/04/05)

In Salisbury -In Salisbury -– up to 6 new patients per week, usually 4up to 6 new patients per week, usually 4– 42 follow up sessions per week42 follow up sessions per week– 1180 ODFS users, 266 2 Channel, over 350 1180 ODFS users, 266 2 Channel, over 350

upper limb & over 350 lower limb exerciseupper limb & over 350 lower limb exercise At present new patients are approx. At present new patients are approx.

50%NHS and 50% private50%NHS and 50% private

Clinical Service 3Clinical Service 3

Set up:Set up:– 2 consecutive days2 consecutive days

– each session 1 to 1 each session 1 to 1 11//2 2 hours hours

Follow up 6 weeks laterFollow up 6 weeks later Then 3 months laterThen 3 months later Then 6 months laterThen 6 months later Then yearly for as long as the system Then yearly for as long as the system

is used.is used.

Clinical Service 4Clinical Service 4

ISO 9000 system in placeISO 9000 system in place Rapid assistance if experiencing Rapid assistance if experiencing

problemsproblems Rapid repair serviceRapid repair service Telephone adviceTelephone advice User questionnaire/ comment bookUser questionnaire/ comment book

Advantages of running Advantages of running a clinical service for a a clinical service for a

research centreresearch centre Increases clinical experienceIncreases clinical experience Ensures research is to the advantage of Ensures research is to the advantage of

patientspatients Improves recruitment for trialsImproves recruitment for trials Constantly raises new areas of researchConstantly raises new areas of research Completes the design process, iterativeCompletes the design process, iterative What’s the point without it.What’s the point without it.

Advantages of running Advantages of running a purely clinical FES a purely clinical FES

centrecentre Better treatment for patientBetter treatment for patient Evidence based treatmentEvidence based treatment Ongoing treatment for a group of Ongoing treatment for a group of

patients who often feel neglectedpatients who often feel neglected– chronic CVA, MS, TBI etcchronic CVA, MS, TBI etc

Service well liked by patientsService well liked by patients

Disadvantages of Disadvantages of running a clinical FES running a clinical FES

centrecentre Long term commitment to Long term commitment to

patients, often many yearspatients, often many years Problems with new, untrained staff Problems with new, untrained staff

coming into the servicecoming into the service Ever increasing patient numbersEver increasing patient numbers TimeTime

Conclusions Conclusions (7/04/05)(7/04/05) In Salisbury we have seen over 2000 In Salisbury we have seen over 2000

patients patients over twelve years longest usageover twelve years longest usage results improve to 4results improve to 411//22 months then constant months then constant estimated UK prevelence 75,000 incidence 6000estimated UK prevelence 75,000 incidence 6000

ODFS recognised by DEC and RCP and RSCGODFS recognised by DEC and RCP and RSCG over 90 courses run, 940+ staff trainedover 90 courses run, 940+ staff trained Equipment production, ISO 9000, CE markingEquipment production, ISO 9000, CE marking

– 2370 ODFS sold2370 ODFS sold

– sold stimulators to 175 centres to date, £1m incomesold stimulators to 175 centres to date, £1m income

www.salisburyfes.com

www.ifess.org