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Invasive and Implanted Medical Devices: Rehabilitation
Therapeutic and Diagnostic Interventions and Their
Contraindications
Douglas P. Stevens, MS, MDNorton Healthcare
Norton Neuroscience InstituteLouisville, KY
Medical Director,SCI&D and PACT Clinics;
Electro-diagnosticianLouisville VAMC
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Disclosures
• I have read Lord of the Rings three times
• I enjoy karaoke
• I like the Beatles and Elvis (in that order)
• CME Staff Disclosures
Professional Education Services Group staff
have no financial interest or relationships to
disclose.
• Douglas P. Stevens, MS, MD
• Physician Advisory Board,
Hill-Rom Inc., The Vest
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Obtaining CME Credit• If you would like to receive CME
credit for this activity, please visit:
http://www.pesgce.com/PVAsummit2
011/
• This information can also be found in
the Summit 2011 Program on page
8.
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Objectives
A. list common implanted and invasive medical
devices.
B. discuss the changing clinical environment of
increasingly providing therapeutic and
diagnostic rehabilitation.
C. verbalize the contraindications in providing
specific rehabilitation interventions to patients
with specific medical devices.
At the conclusion of this activity, the participant will be
able to:
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Objectives• The participant will be able to list common implanted
and invasive medical devices.
• The participant will be able to discuss the changing
clinical environment of increasingly providing
therapeutic and diagnostic rehabilitation.
• The participant will be able to verbalize the
contraindications in providing specific rehabilitation
interventions to patients with specific medical devices.
of
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What You Should Learn
Big Picture• The ‘categories’ of devices
• What it is that goes ‘wrong’
• What is safe, and what is dangerous
• Therapeutic interventions
• Diagnostic interventions
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NO DEAD PATIENTS
Don’t order short-wave diathermy
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What You Should Learn
Big Picture
• The ‘categories’ of devices
• What it is that goes ‘wrong’
• What is safe, and what is dangerous
• Therapeutic interventions
• Diagnostic interventions
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Implanted & Invasive
Device ‘Categories’
• Hydraulic / Mechanical
(pacers, stimulators)
(pumps)
(implants)
(Bladder/phrenic stim)
(cardiac pacer, DBS)
• Space-occupying
• Electrical
• Passive receivers
• Pulsed generators
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Space-occupying Devices
• Penile implant
• Breast implants
• Orthopedic implants
• Tissue expanders
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Breast Implants
At risk from mechanical trauma
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Orthopedic Implants
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Implanted & Invasive
Device ‘Categories’
• Hydraulic / Mechanical
(pacers, stimulators)
(pumps)
(implants)
(bladder/phrenic stim)
(cardiac pacer, DBS)
• Space-occupying
• Electrical
• Pulsed generators
• Passive receivers
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Electrical Devices
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Electrical Devices• Cardiac pacer / defibrillator
• Diaphragm pacers
• Vagus nerve stimulator
• Deep-brain stimulators
• Spinal cord stimulator
• Gastric stimulator
• Bladder-stimulator (Vocare)
• Free-hand system • Phrenic nerve
Pulsed
Generators
Passive
Receivers
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Schematic of Pacemaker
The most commonly
encountered
device
Pulsed
GeneratorLead
Constant
Desire
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Phrenic Nerve Stimulator
Intermittent desire
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Diaphragm Pacer
External
Pulse
Generator
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Deep Brain Stimulators (DBS)
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Phrenic nerve pacer
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Bladder stimulator
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Bladder stimulator
Passive
Receiver
in Vocare
Pulsed
Generator
in InterStim
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Bladder (and bowel)
stimulator
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Hydraulic/Mechanical Devices
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Implanted & Invasive
Device ‘Categories’
• Hydraulic / Mechanical
(pacers, stimulators)
(pumps)
(implants)
(bladder/phrenic stim)
(cardiac pacer, DBS)
• Space-occupying
• Electrical
• Pulsed generators
• Passive receivers
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Implanted
Hydraulic Devices
• Ventricular-assist device (VAD / LVAD)
• Intra-thecal pumps
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Intrathecal Pumps
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Old Pump vs. New Pump
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Old Pump vs. New Pump
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Intrathecal Pumps
www.medtronic.com
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Baclofen flow rate as a function
of altitudetemperature(hyperbaric will reduce)
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Implanted
Hydraulic Devices
• Ventricular-assist device (VAD / LVAD)
• Intra-thecal pumps
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Ventricular-assist device
External
Pulse
Generator
Pump
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Invasive Devices• PICC line
• Peripheral IV
• Chest tube
• Gastric/nasogastric tube
• Tracheostomy tube / Ventilator
• Insulin pump
• Ventricular-assist device (VAD or LVAD)
• Diaphragm pacer
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Objectives
• The participant will be able to verbalize the
contraindications in providing specific rehabilitation
interventions to patients with specific medical devices.
of
• The participant will be able to list common implanted
and invasive medical devices.
• The participant will be able to discuss the changing
clinical environment of increasingly providing therapeutic
and diagnostic rehabilitation.
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What You Should Learn
Big Picture
• The ‘categories’ of devices
• What it is that goes ‘wrong’
• What is safe, and what is dangerous
• Physio-therapeutic interventions
• Diagnostic interventions
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Therapeutic Interventions
• Functional electrical stimulation / TENS
• Therapeutic ultrasound / phonophoresis
• Iontophoresis
• Diathermy (short-wave)
• Topical heat / cold
• Infra-red light therapy
• Massage
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Therapeutic Interventions• Body-weight support systems
– harness with Therastride and Lite-Gait– Lokomat
• Treadmill-training (ABT=Activity-based therapy)
• Aquatic therapy
• Lithotripsy
• Electroconvulsant therapy
• Transcranial magnetic stimulation
• Hyperbaric treatment
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TENS / FES / ELECTRODIAGNOSIS
• should not be used in patients with a
defibrillator or pacemaker (especially of
the demand type)
• caution in any pulse-generator device
(RELATIVE)
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Safety of nerve conduction
studies in patients with
implanted cardiac devices.Schoeck AP, Mellion ML, Gilchrist JM, Christian FV, Muscle Nerve. 2007
Apr;35(4):521-4.
We conclude that routine NCS is safe in
patients with implanted cardiac pacemakers
with bipolar sensing configurations and
defibrillators.
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LOKOMAT Contraindications
• Mechanical ventilation
• Severe vascular disorders of the lower limbs
• Cardiac contraindications
• Severe cognitive deficits
• Open skin lesions in the area of lower limbs and torso
• Circulatory problems
• Fixed contractures or hip, knee, ankle arthrodesis
• Bone instability
• Orthosis not adapted for the body (lower limbs)
• Body weight greater than 135 kg
ACTVITITY-BASED THERAPY
CONTRAINDICATIONS
WITH
DEVICES
NO absolute contraindications
Relative contraindications
of
mechanical compression
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Objectives
• The participant will be able to verbalize the
contraindications in providing specific rehabilitation
interventions to patients with specific medical devices.
of
• The participant will be able to list common implanted
and invasive medical devices.
• The participant will be able to discuss the changing
clinical environment of increasingly providing therapeutic
and diagnostic rehabilitation.
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What You Should Learn
Big Picture
• The ‘categories’ of devices
• What it is that goes ‘wrong’
• What is safe, and what is dangerous
• Therapeutic interventions
• Diagnostic interventions
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• Magnetic resonance imaging (MRI)
• Diagnostic ultrasound – Neuromuscular
– Musculoskeletal
• Computerized-tomography (CT)
• Positron-emission tomography (PET)
• Electrodiagnosis
Diagnostic Interventions
CONTRAINDICATIONS ?
YES
NO
NO
NO
RELATIVE
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• Lehman JF, Brunne GD, Martinis AJ, McMillan JA. Ultrasonic
effects as demonstrated in live pigs with surgical metallic
implants. Arch Phys Med Rehabil. 1959;40:483-488.
• Lotsova EI. Effect of ultrasound on the strength of metal fixing
pins for fractures and joint injuries. Mechanics of Composite
Materials. 1979;15:330.
• Gersten JW. Effect of metallic objects on temperature rises
produced in tissues by ultrasound. Amer J Phys Med.
1988;37:75-82
Ultrasound
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What You Should Learn
Big Picture
• The ‘categories’ of devices
• What it is that goes ‘wrong’
• What is safe, and what is dangerous
• Therapeutic interventions
• Diagnostic interventions
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Impact of the Intervention
• Electrical interference
• Excess heat
• Migration of device and/or leads
• Magnetic interference
• Hydraulic (flow) interference
• Mechanical compression
(what goes wrong)(Electromagnetic induced
currents)
(Elongated metal; i.e. LEAD TIPS)
(Negligible, ‘BUT’)
(Magnetic components)
(Temperature &
pressure)
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Practically speaking• Of what is the device made ?
• Does it have a ‘lead’ ?
• Is anything within it ferro-magnetic ?
• Is it electrical ?
• Is there a magnet within it ?
• How is the device damaged ?• Is it ruptured ?
• Is it melted ?
• Is it moved ?
• Is it ‘shorted-out’ ?
• Is it ‘frozen’ (stopped) ?
• How is the patient injured ?
• Are they burned ?
• Are they ‘stimulated’ ?
• Are they deprived of device intent ?
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What You Should Learn
Big Picture
• The ‘categories’ of devices
• What it is that goes ‘wrong’
• What is safe, and what is dangerous
• Therapeutic interventions
• Diagnostic interventions
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May be used over or near:
• Any part of the body - including the spine
• Metal implants, plates, pins and screws
• Pacemakers
• Defibrillators
Infrared-light Therapy
Superficial heat & cold
Ultrasound
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MRI Contraindications• Cardiac pacemakers
• Neurostimulators (DBS, Vagus, Phrenic)
• Penile implants Duraphase & Omniphase
• the only 2 out of 13 tested
• Gastric stimulators
• Programmable VP shunts
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OK with MRI• Vocare bladder system (1.5 T)
• Freehand system (1.5 T)
• Heart valves
• Coils, filters, stents (if non-ferromagnetic)
• if weakly ferromagnetic, wait 6-8wks
• Breast implants; most penile implants
• Orthopedic implant
• Intrathecal pumps
• Passive receivers (conditional & 1.5 T)
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www.MRIsafety.com
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Thank
You
QUESTIONS?