Transcript Ultrasound Imaging Capability for Surgical Drills

Julianna Ianni
Meher Juttukonda
David Morris
Advisor: Dr. Jadrien Young, M.D.
What is Otologic Surgery?
 Surgery of the ear
 Mastoidectomy
 Mastoid

air-filled spaces behind the ear
 Surgery to remove cells from the mastoid
 Uses


to treat anti-biotic resistant infections in the region
to insert a cochlear implant
 30,000 to 60,000 performed annually in the U.S.1
Anatomy of the Ear
Objectives
 To find an ultrasound
transducer that is
compatible with an
otologic drill
 To calculate the
thickness of the mastoid
bone using A-mode US
 To shut off the drill when
the bone has been
drilled
Why Ultrasound?
Category
CT - Method
Ultrasound
Safety
Ionizing Radiation
No Ionizing Radiation
Real-time Data
Time
Drilling Platform
Not necessary
Invasiveness
Invasive
Non-invasive
Past Work
 Studied ultrasound equipment in order to
determine the most effective way to produce
accurate images
 Researched the best transducer frequency for
imaging that region of the skull
 Met with Dr. Young and discussed the surgical
aspects required to have a usable drill
 Read several papers and technical
documentation regarding the operation of
ultrasound surgical imaging technology
 Developed the website
 Updated list of design goals
 Observed use of otologic drills & identify design
constraints
 Identified potential design obstacles
 Generated design ideas concerning mechanism
of attachment
 Restructured design goals focusing more on
finding an ultrasound transducer compatible
with an otologic drill
Current work
 Finding company that can build hollow annular
transducer to specifications
 Performing measurements w/larger transducer on
material samples analogous to skull bone
 Researching renting a ultrasound depth gauge to test
on cadaver bone for proof of concept
Simulation of Signal
 Assumptions
 Speed of Sound in Skull Bone = 2700 m/s3
 Only Reflection/Transmission & Attenuation

No Scattering
 Results
1
1
0.9
0.8
Fractional Amplitude
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.2
0.4
0.6
0.8
1
Time (s)
1.2
1.4
1.6
1.8
-5
x 10
Solidworks Prototype
Side View
Top View
Bottom View
Future Work
• Deciding type & shape of ultrasound transducer
• Determine ideal frequency
• Developing method to connect to current power
source
• Developing cooling system
• Developing a B-Mode to image the path and
Doppler mode to measure blood flow
• Building & testing prototype
References
 1. French, LC et al. “An estimate of the number of
mastoidectomy procedures performed annually in the
United States”. Ear Nose Throat J. 2008 May; 87(5): 267-70.
 2. Ear Anatomy:
http://www.umm.edu/imagepages/1092.htm
 3. Clement, GT et. Al. “Correlation of Ultrasound Phase
with Physical Skull Properties”. Ultrasound in Medicine &
Biology. 2002 May; 28(5): 617-624.