1. Julianna Ianni Meher Juttukonda David Morris Advisor: Dr. Jadrien Young, M.D.

2. 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

3. Anatomy of the Ear

4. 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

5. Why Ultrasound? CategoryCT - MethodUltrasound SafetyIonizing RadiationNo Ionizing Radiation Real-time Data TimeDrilling PlatformNot necessary InvasivenessInvasiveNon-invasive

6. 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

7. 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

8. Simulation of Signal Assumptions Speed of Sound in Skull Bone = 2700 m/s 3 Only Reflection/Transmission & Attenuation No Scattering Results

9. Solidworks Prototype Side View Top View Bottom View

10. 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

11. 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 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.