Presentation on theme: "Functional Electrical Stimulation (FES) - a re-emerging technology Ian Swain Dept. of Medical Physics and Biomedical Engineering, Salisbury District Hospital,"— Presentation transcript:
Functional Electrical Stimulation (FES) - a re-emerging technology Ian Swain Dept. of Medical Physics and Biomedical Engineering, Salisbury District Hospital, U.K. Academic Biomedical Engineering Research Group, Bournemouth University, U.K.
What are the Prerequisites for a Clinical FES Service l Clinical demand l Evidence that the technique works l Management, Consultant, GP/PCT and patient support - all ideally needed l Adequate and reliable funding l Information l Reliable equipment l Trained staff
Demand l 118,000 new strokes per year in UK, –10,000 under 50 –1,000 under 30 l 80% survival, 30% complete recovery l about 10,000 left with dropped foot l 85,000 MS in UK l CP l Head injury l Incomplete Spinal cord injury
Evidence - Randomised controlled trial of the Odstock Dropped Foot Stimulator Jane Burridge, Paul Taylor, Ian Swain Salisbury District Hospital
Study l 32 subjects who had had a Stroke randomly allocated to an FES and a control group l Each group received 10 one hour sessions of physiotherapy over 1 month. The FES group used the stimulator in the sessions and at home l Assessments at start, 1 month and three months
Assessments l Walking speed l Physiological Cost Index (PCI) l Spasticity - Watenberg pendulum drop test l Mobility questionnaire l Nothingham QoL Health profile l Hospital Anxiety and Depression index l Use of stimulator questionnaire
Walking speed at 3 months l With stimulation20.5%p < 0.01 l No Stimulation0.12%p = 1 l Control5.2%p = 0.38
PCI at 3 months l With Stimulation-24.1%p < 0.01 l No stimulation-11.8%p = 0.67 l Controls-3.9 %p = 0.47
Quadriceps Spasticity l A reduction in spasticity seen in the control group after 10 sessions of physiotherapy. This was lost after 2 months l A reduction in spasticity in the FES group at the third assessment
Hospital Anxiety and Depression Index (HAD) l Treatment Group –Depression –5.5 3.5 p = –Anxiety 5.3 3.0 p = l Control Group –Depression –4.3 3.8 p = –Anxiety 4.8 3.7 p = 0.096
Conclusions l Significant increase in walking speed in FES group - no change in control group l Significant fall in PCI in FES group - no change in the control group l Reduction in spasticity in FES group only l Reduced HAD score l Positive cost-benefit (QALY gain of 0.042)
Patients treated in Salisbury (7/04/05) l Service running for eleven years l Over 2000 patients referred to the service and seen, not including the many who have participated in clinical trials l 880 CVA, 540 MS, 120 SCI, 63 CP, 25 facial, 31 TBI, plus other neurological conditions
Patient with SLE, and subsequent bilateral CVA
Changes in Walking Speed
Changes in PCI
Reliable equipment l MUST meet patients needs l User involvement essential to design process l large numbers needed to trial, then modify design accordingly, iterative process l RELIABLE l ODFS footswitch works every time, fifteen years development ~1-200,000 cycles, ~ 6 / 12 use l Safe, and built to recognised standards l Quality control, e.g. ISO 9000 l CE marked
Equipment Currently Available l Few practical systems available such as the FreeHand, HandMaster, Vocair (Brindley Bladder Stimulator), ODFS etc l From Salisbury we can supply (to registered users) –ODFS –2 channel ODFS –2 and 4 channel exercise stimulators –consumables –implanted dropped foot system - STIM-U-STEP
Stim-U-Step l 2 channel implanted stimulator –CE marked, clinical service later this year l Deep branch –dorsiflexion + inversion l Superficial branch –dorsiflexion + eversion l Developed with EU funding with, Salford, Het Roessingh and Finetech
Staff Training l FES equipment has a tendency to be sold from back pages of newspapers l FES is not a treatment in itself it is a part of a rehabilitation programme –use with BoTox, orthotics, therapy etc l Only trained staff can order and fit equipment. l Therefore continuous training, education and support needed
Patient Support l Clinical guidelines/ Care pathways –82%success at initial assessment l Prompt repair service l Ongoing support for staff and patients –86%compliance at 1 year l Audit and regular questionnaires
How is the ODFS used? Stroke l Use every day 48% l Use 4-6 days15% l 10 to 100 yds38% l 100 to 500 yds33% l 500 yds to 1 m12% l 1 m + 8% MS l Use every day 40% l Use 4-6 days 28% l 10 to 100 yds* 40% l 100 to 500 yds** 38% l 500 yds to 1 m 8% l 1 m + 5% *EDSS **EDSS
Most important reason Stroke l Less effort27% l Long term hope20% l Carryover22% l More confident10% MS l Less effort33% l Trip less28% l Walk further10% l More confident10% l No stick10%
Clinical Treatment Stroke l very good85% l good12% MS l very good 75% l good 25%
Improving hand function
Exercises l Reciprocal flexion and extension of the wrist and fingers, optionally with the lumbrical muscles. l Exercises began at two periods of 15 minutes a day, increasing to two periods of 1 hour by three months l 20 Hz, 300 micro Seconds, up to 80 mA.
Measurements 1.The Jebsen-Taylor hand function test. 1.The Jebsen-Taylor hand function test. 2.Static two point discrimination 2.Static two point discrimination 3.Power, pinch and key grip strength 3.Power, pinch and key grip strength
JEBSEN-TAYLOR % CHANGE SUBJECTS % CHANGE
Conclusions 1.There are statistically significant improvements in static two point discrimination score, Jebsen- Taylor test score and key grip strength following three months of electrical stimulation exercises. 1.There are statistically significant improvements in static two point discrimination score, Jebsen- Taylor test score and key grip strength following three months of electrical stimulation exercises. 2.It is not clear if there are significant benefits in ADL, though some anecdotal evidence was reported. 2.It is not clear if there are significant benefits in ADL, though some anecdotal evidence was reported. 3. There is evidence to support the use of FES in shoulder subluxation (Chae,J) and useful in improving hygiene in severe spasticity. 3. There is evidence to support the use of FES in shoulder subluxation (Chae,J) and useful in improving hygiene in severe spasticity.
The clinical service in Salisbury
Clinical Service 1 l Dropped foot correction l Bilateral dropped foot l More complex movement problems –2 channel stimulator –in conjunction with orthotics l Upper limb function l Facial stimulation l Orthopaedic
Clinical Service 2 (07/04/05) l In Salisbury - –up to 6 new patients per week, usually 4 –42 follow up sessions per week –1180 ODFS users, Channel, over 350 upper limb & over 350 lower limb exercise l At present new patients are approx. 50%NHS and 50% private
Clinical Service 3 l Set up: –2 consecutive days –each session 1 to 1 1 / 2 hours l Follow up 6 weeks later l Then 3 months later l Then 6 months later l Then yearly for as long as the system is used.
Clinical Service 4 l ISO 9000 system in place l Rapid assistance if experiencing problems l Rapid repair service l Telephone advice l User questionnaire/ comment book
Advantages of running a clinical service for a research centre l Increases clinical experience l Ensures research is to the advantage of patients l Improves recruitment for trials l Constantly raises new areas of research l Completes the design process, iterative l What’s the point without it.
Advantages of running a purely clinical FES centre l Better treatment for patient l Evidence based treatment l Ongoing treatment for a group of patients who often feel neglected –chronic CVA, MS, TBI etc l Service well liked by patients
Disadvantages of running a clinical FES centre l Long term commitment to patients, often many years l Problems with new, untrained staff coming into the service l Ever increasing patient numbers l Time
Conclusions (7/04/05) l In Salisbury we have seen over 2000 patients l over twelve years longest usage l results improve to 4 1 / 2 months then constant l estimated UK prevelence 75,000 incidence 6000 l ODFS recognised by DEC and RCP and RSCG l over 90 courses run, 940+ staff trained l Equipment production, ISO 9000, CE marking –2370 ODFS sold –sold stimulators to 175 centres to date, £1m income