Transcript 4/5/07 - Research - Vanderbilt University

Quantitative Detection of
Parkinson's Disease Symptoms
Advisor:
Dr. Chris Kao
Project Team:
Kylen Bares
Eddie Cao
Dr. Changquing (Chris) Kao, M.D.,
Ph.D.
Research Associate
Professor in Department
of Neurosurgery at
Vanderbilt University
Clinical interest:
– Microelectrode brain mapping
for target localization of deep
brain stimulation treatment of
movement disorders
Research focus:
– Electrophysiology in nerve
stimulation, epilepsy, pain
control and head injury
What is Parkinson’s Disease?
Neurodegenerative disorder
caused by damaged or dead
dopamine-releasing neurons in
the substantia nigra
Dopamine: neurotransmitter
that carries information from
neuron to neuron and
eventually to the muscles
Brain no longer able to direct
or control muscle movement in
a normal manner.
Half a million people every
year are affected by
Parkinson’s
Symptoms
Tremor or trembling in hands, arms, legs,
jaw, and face
Rigidity or stiffness of the limbs and trunk
Slowness of motor movements
Postural instability or impaired balance
and coordination
Reduction in blinking rate of eyes
Treatment
Drugs: Levodopa/ L-Dopa
Drugs designed to mimic
dopamine effects or
counteract acetylcholine
effects
Pallidotomy: Section of
globus pallidus removed
Deep Brain Stimulation
(DBS) : Implants
stimulators that block
brain signals causing
rigidity, tremors and other
symptoms
http://www.pdmdcenter.com/articles/HopkinsWeb/index.html
http://www.pdmdcenter.com/articles/HopkinsWeb/index.html
Deep Brain Stimulation
3 parts: lead electrode, extension wire,
neurostimulator
Lead electrode: thin, insulated wire inserted
through the skull within the tip placed inside
predetermined target area (located by MRI or
CT scan)
Extension: thin, insulated wire connecting lead
and neurostimulator, passing under the skin
Neurostimulator (NS): “battery” pack implanted
under the skin near neck or torso
Electrical stimulation is delivered from NS to
affected target area in the brain, blocking
abnormal nerve signals
Problem
Quantifiable measurement of the
symptoms of Parkinson’s disease is
needed to maximize therapy.
Unfortunately, there currently does not
exist a method known to be reliable.
Our Device
A pneumatic-actuated frame that fits around the
right arm
- uses air pressure for individual flexion of the
fingers and forearm
- measures the pressure exerted on the
actuator piston
- this pressure corresponds to the force
needed to move the arm and, therefore, the
rigidity of the arm muscles
Each patient will be their own control since we
only need to measure effectiveness of
treatment
Our Device
Composed of two main parts
– Control Box
Contains the pneumatic valves and pressure
manifold
– Arm frame
Encloses the arm and translates motion of
pneumatic cylinders into motion of the arm
Gauge cluster
Air cylinders
4-way valve assembly
Forearm
section
Cylinder
connecters
Foam
padding
Fiberglass
resin gel
Upper arm
section
Pneumatic Circuit Diagram
Air cylinder
Glove with
air cylinder
attachments
on the
fingertips
Forearm section
of arm-frame
Connecting pins
Air cylinder
Elbow pivot joint
Upper arm frame
Current Status
ProE model of arm frame is completed
Materials to build prototype have been
collected. Fabrication is underway.
Since the design prototype changes from
3 cylinders to 2, the control box needs to
be re-built. Appointment next week at
Meredith Air Controls to acquire the parts.
Some answered questions
Anesthesia does affect rigidity, but cannot be eliminated, so
administration is localized.
Some patients do have tremors, which, however, don’t affect the
effectiveness of measurement.
Stimulation mapping will quantitatively detect efficacy more
objectively about muscle function improvement.
In-house air pressure is not available in the OR. An external source
is needed.
– Testing – Household air compressor (~125 psi)
– In the OR – likely a compressed air tank with regulator set to ~125 psi
The control box allows the operator to slowly flow air into the desired
side of the cylinder actuator, thus applying force on the actuator
piston and the arm via the arm-frame.
Ultimate Goals
To create and test the viability of a fully
controllable pneumatic device that forces
movement in the arms of actual
Parkinson’s patients and accurately
displays the required pressure to induce
movement.
To enable the device to adjust in order to
comfortably fit multiple patients.