Ultrasound Imaging Capability for Otologic Surgical Drills Julianna

Ultrasound Imaging Capability for Otologic 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 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/s 3 �Only Reflection/Transmission & Attenuation � No �Results Scattering

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.