Ultrasound Imaging Capability for Otologic Surgical Drills

Julianna IanniMeher Juttukonda

David MorrisAdvisor: Dr. Jadrien Young,

M.D.

What is Otologic Surgery?Surgery of the earMastoidectomy

Mastoid air-filled spaces behind the ear

Surgery to remove cells from the mastoidUses

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

ObjectivesTo 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 RadiationReal-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 workFinding company that can build hollow

annular transducer to specificationsPerforming 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 SignalAssumptions

Speed of Sound in Skull Bone = 2700 m/s3

Only Reflection/Transmission & Attenuation No Scattering

Results

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Solidworks PrototypeSide 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

References1. 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.