Non-Transcranial
Electroanesthesia
Group 2
Students: Ryan Demeter
Matt Jackson
Caroline Schulman
Matthew Whitfield
Advisors: Doctor Paul King and Doctor James Berry
Project Definition
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Design, build, and test a system for both
administering and recording data related
to vagal nerve stimulation.
Topics to cover: Project Background,
Design Ideas, Stimulation (production and
application) Techniques, Testing, Overall
Status, Current Status, and Key Issues
2
Project Background
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Advisor: Dr. James Berry (Dept. of
Anesthesiology Multi-Specialty Division)
Computer Engineering expertise from Dr.
Andrew Dozier (Dept. of
Electrical/Computer Engineering)
3
Project Background
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Currently, electroanesthesia devices are in use in Europe.
In less developed countries where anesthesia technology
is lacking, an electroanesthesia device would reduce
both the cost of the procedure and the need for
technical personal (anesthesiologist).
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S. Leduc --> Europe, Japan, Russia, and Germany
Activation of a theoretical pain center
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35 V, 4 mA, 100 Hz, rectangular pulsating signal
Alternative method
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Descending mechanism and the interconnections within the brain
4
Background:
Electroanethesia
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Quicker recovery time and less biological effect during
and after surgery (Photiades, 218-225)
Heal better (Sances and Larson, 21-27)
Less a build up of gases in the body (Sances and Larson,
218-219)
EEG and ECG
Electrolyte levels in extracellular and intracellular fluid of
the brain (Sances and Larson, 148-175)
Decreased gastric acid secretion (Sances and Larson, 3346)
FDA
Kano et al. (1976)
Vagal Nerve Stimulation (Kirchner et al., Ness et al.)
5
Background: Nerve Information
Vagal Nerve
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10th cranial nerve
Location: both sides of the neck
Composition: A, B, and C-fibers
Function: motor and sensory (visceral
afferent) signals
C-fibers and Pain
Not fully myelinated until adulthood
(Koo et al. 429-433)
Shown to help control seizures and
depression
Best Route to the Central Nervous
System Rutecki (1990)
Facial Nerve
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7th cranial nerve
Location: both sides of the head by the ear
Composition: Branches of fibers
Function: motor and sensory signals
Facial Expression
Myelinated
NO research into therapeutic use
Does lead into the Central Nervous
System
6
Background:
Vagal Nerve Fiber Information
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A-fibers
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B-fibers
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Adapt to constant stimulus and exhibit presynaptic
inhibition
Respond well to low stimulus (George et al. s56s61)
Conduction Speed: 90 to 30 m/s1
Selectively activated by low intensity VNS
No effect on EEG recorded in the rats studied by
Hammond et al. (1992)
Respond well to low stimulus (George et al. s56s61)
Conduction Speed: 20 to 10 m/s1
No effect on EEG recorded in the rats studied by
Hammond et al. (1992)
C-fibers
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[1] Woodbury,
Continue to fire with constant stimulus
Conduction Speed: 1.6 to .3 m/s1
7
DM and J.W. Woodbury. “Effects of Vagal Stimulation on Experimentally Induced Siezures in Rats.” Epilepsia. 31.Suppl. 2 (1990): s7-s19
Methods
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Computer system
Vital signs monitoring equipment
Testing
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Phase I:
- Device components connected and tested to assure
compatibility
-Software integrated and tested to assure
compatibility and proper operation
-Test inputs and outputs of device
Phase II: Applicator testing to assure proper outputs
and operation
Phase III: Testing of device operation with a rat
8
Design 1
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Too Complex
Un-needed
components
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Design 2
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Less Components
Needed
Laptop keyboard
eliminates need for an
additional keyboard
Internal components
dependent on
stimulation method
10
Cost
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Gas anesthesia
 In the case of gas
anesthesia, more is
required for treatment and
cost are around twenty to
forty dollars a patient
(Kurpiers et. al., 69-75).
Liquids
 between three and nine
times as expensive as gas
anesthesia per volume
(Kurpiers et. al., 69-75).
Electroanesthesia will reduce
the high cost of anesthesia for
surgery and other procedures
by reducing the need to keep
large quantities of liquid and
gas anesthesia on hand.
11
Stimulation Parameters
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Stimulation of both Vagal Nerves
20 Hz Rectangular pulse signal
Pulse length of 250 µs (Liporace et al.
885-886)
50 µA (Kirchner et al. 1167-1171)
25 V
Need to consult more with Dr. Berry to
estimate best parameters
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Soundcard
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Virtins Sound Card Signal Generator
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LabVIEW
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LabVIEW user interface
DAQ controller
Expensive to actually buy DAQ controller
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Block Diagram View
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Delivering Electroanesthesia
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Option 1: Cortical Stimulator (Ojemann
Cortical Stimulator)
- Advantage: Add gain stage
- Disadvantage: Knobs
not computer
compatible, gain stage
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Delivering Electroanesthesia
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2: Gain Stage
- Advantage: Computer
compatible
- Disadvantage: Noise,
unforeseen circuitry problems
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Recent Contacts
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Ray Booker - Simulation engineer at Ctr.
for Medical Simulation
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Discussed head and neck phantoms
Cost
 Availability
 Function
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Sim-man
-Most expensive and limited funds (NEGATIVE)
-Not immediately available (NEGATIVE)
-Possible damage from device (NEGATIVE)
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Airway Model
-Relatively inexpensive (POSITIVE)
-Immediately available (POSITIVE)
-Thin, plastic head and
neck (NEGATIVE)
-No damage from electric shock
(POSITIVE)
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Plaster Cast
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Inexpensive (POSITIVE)
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Can be made and remade whenever needed (POSITIVE)
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Dimensions somewhat flexible (POSITIVE)
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Current Status
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Sent out NCIIA report before winter break
Laptop for project given by Dr. Berry and
started programming in LabView
Applied to BMEidea
Divided tasks among group members
Consulted Ray Booker for test subjects
and materials
Assigned weekly meeting times
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Overall Status
Month
Description
November 2004
Look into previous research done on VNS and Electroanesthesia. Develop schematics
and possible device physical designs. Start design development.
December 2004
Proceed with research and finalize our design approach. Assemble basic design
components. Develop software and user interface.
January 2005
Begin designing prototype model and testing.
February 2005
Proceed with prototype design and testing. Obtain IRB approval to test our device.
March 2005
Run experiments if approved and make modifications where necessary. Continue
work-up and finalize design.
April 2005
Continue to finalize Design and prepare paper and presentation poster.
23
Most Important References
10 of 31
Ammons, W. Steve, Robert W. Blair, and Robert D. Foreman. "Vagal Afferent Inhibition
of Primate Thoracic Spinothalamic Neurons." Journal if Neurophysiology 50.4
(October 1983): 926-940.
Bohning, DE, MP Lomarev, S Denslow, Z Nahas, A Shastri, and MS George.
"Feasibility of vagus nerve stimulation-Feasibility of vagus nerve stimulationsynchronized blood oxygenation level-dependent functional MRI." Investigative
Radiology 36.8 (2001): 470-479.
Fries, Richard. E-mail interview. 5 2005.
“FDA: Significant Risk and Nonsignificant Risk Devices”. Mount Sinai School of
Medicine. 1 September 2005.
<http://www.mssm.edu/irb/pdfs/appendix/13.pdf>
Hammond , EJ, BM Uthman, SA Reid, and BJ Wilder. "Electrophysiological studies of
cervical vagus nerve stimulation in humans: I. EEG effects.." Epilepsia. 33 (1992):
1013-1020.
Kano, T, GS Cowan, and RH Smith. "Electroanesthesia (EA) studies: EA
produced by stimulation of sensory nerves of the scalp in Rhesus
monkeys." Anesthesia and Analgesia (1976): 536-541.
Kirchner MD, A., F. Birklein MD, H Stefan PhD, and H.O. Handwerker PhD.
"Left vagus nerve stimulation suppresses experimentally induced
pain." Neurology 55.8 (2000): 1167-1171.
Melzack, Ronald, and Patrick D. Wall. "Pain Mechanisms: A New Theory." Science
150.3699 (1965): 971-979.
Sances Jr., Anthony, and Sanford J. Larson. Electroanesthesia
Biomedical and Biophysical Studies. New York: Academic Press,
Inc., 1975.
Woodbury, DM and J.W. Woodbury. “Effects of Vagal Stimulation on Experimentally Induced Siezures in Rats.” Epilepsia. 24
31.Suppl. 2 (1990): s7-s19