1. Image Guided
System for
Intracranial
Neurosurgery 1

2. Project Overview
• Problem:
– Neurosurgery is complicated, expensive, and not fully
accessible
– McKnight Brain Institute developed surgical planning
software that generates a 3D printed mask guide
– Mask cannot be sterilized, software is not accessible
• Solution:
– Create an easy to use, web based interface for software
– Design an articulating arm that can align with position
set by mask and maintain that position after sterilization
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3. Software Specifications
• Simple easy to follow user interface
• Web Accessible
• Ability to upload MRI/CT files
• View target and entry point in all three
anatomical planes
• Ability to view 3D model of patient head
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4. Software Overview
• Developed a simple and easy to use web-
based user interface
• No cost to develop
• Not hardware dependent
• Not browser dependent
• Functional 3D model from MRI files
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5. Hardware Specifications
Mechanical interface for positioning of surgical probe
according to target location specified by software-
generated mask:
– Simple, Easy to use articulating arm
• Pneumatic, passively locking device
• Manual manipulation
• Minimize size and weight
• Compatible w/ Medtronic articulating arm
• 5 degrees of freedom
• Maintain sterility: detachable probe head
• Maintain accuracy of probe positioning ~2 mm
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6. Hardware Design Overview
“Dumbbell” design
• 5” rigid shaft
• Ball joints
• Cylinder enclosures
Pneumatic locking
mechanism
• Passively locks
• Air pressure supplied
w/ foot pedal
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7. Pneumatic Locking
Mechanism
• Stacks of washers
and wave springs
clamp ball
• Silicone tubing inflates
to unclamp ball
• Ball freely moves
while air pressure is
supplied
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8. Test Overview
Tests were performed using a phantom
to set a target point whose 3D coordinates
can be measured in millimeters.
1. Locking Mechanism Test
AIM: To assess the accuracy of the
pneumatic locking mechanism.
• Unlock arm, line up to target position, lock arm, measure any
deviation from target position
2. Loading Test
AIM: To determine how much force the arm can withstand while
maintaining the set position.
• Applied varying upward loads to see working deflection after
locking
• Assessed permanent deflection after force is removed 8

9. Locking Test Results
The average error was
found to be:
• 1.6±0.43 mm in the
x-direction
• 1.15±0.37 mm in the
y-direction
• 0.6±0.4 in the z
direction.
Prototype was
successful in meeting
+/- 2mm accuracy
standard.
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10. Loading Test Results
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11. Technical Performance Measures
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12. Cost Analysis
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• Total cost of prototype fabrication was
$754.34
• Substantially cheaper than current system
(roughly $1 Million)
• Improved manufacturing and producing in
bulk could make a device for less than
$100

13. Recommendations
– Hardware
• Improve accuracy and reduce cost through optimized
manufacturing
– Software
• Allow for multiple trajectories to be set by the surgeon
• Connect to server and perform tests
– Testing
• Increase sample size
• Perform Survey of Surgeons
• Test in operating room
– Product
• File for patent
• FDA 510(k) Acceptance 13

14. Conclusions
• Successful at creating a functional, two part
image-based guidance system
– Software has high data capacity, user-friendliness, and
accessibility
– Hardware has a working pneumatic locking
mechanism amenable to operating room
• System is close to hoped accuracy
– Errors attributed to manufacturing
• Prototype is approved by consulted surgeons
• Product is much less expensive than the current
standard
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15. We would like to
thank:
• Dr. Scott Banks
• Dr. Frank Bova
• Dr. Didier Rajon
• UF Dept. of
Neurosurgery
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16. Irene Freire, CSE
Samantha Shuhala, ME
Emily Churchwell, BME
Celeste Rousseau, BE
Medhut Alnadi, BME
Matthew Thrush, ME
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