Download Project #13: Functional Model of a Cadaveric Human Middle Ear

Project #13: Functional Model of a
Cadaveric Human Middle Ear
NSF-UC 2012-2013 Academic-Year REU Program
Faculty Mentor: Vasile Nistor
Application Deadline: August 16, 2012
Abstract: The goal of this project is to develop a functional model of the human middle ear,
including the tympanic membrane, malleus, incus, stapes and suspensory ligaments. These
structures are the mechanism by which airborne vibrations are transferred to the fluid medium in
the inner ear, allowing for the generation of a nerve signal and the perception of sound. When
this system is disrupted, it results in Conductive Hearing Loss. Surgery is necessary to restore the
mechanical function of these structures, which are only millimeters long. This model is desired
by surgeons to provide an alternative means by which the surgical repair of these structures with
a prosthesis can be functionally evaluated. Cadavers and animal models are the current standard
for this practice, but the cost of obtaining and maintaining these limits their applicability in
practice and training, especially by residents and
other novice surgeons.
Models of a cadaveric middle ear have been
fabricated based on MicroCT images using
Amira® (Visage Imaging, San Diego, CA). The
bones of the middle ear were replicated at 10:1
scale using a silica powder printer. Joints and
other soft tissues were molded from RTV
urethanes of appropriate material properties. A
model of the intact middle ear as well as with an
inserted prosthesis (left) have been fabricated.
REU students working on this project will work
with a graduate student to characterize the mechanical transfer ability of the fabricated model
relative to previously published data for the native middle ear. Data will be compared for both
the complete and prosthetic models. A variety of acoustic and mechanical stimulation methods
will be assessed by both accelerometer and Laser Doppler Vibrometer measurements. Students
will collect and interpret data and present it in a manner such that it can be included in a
published work in a journal such as Hearing Research or The Laryngoscope. The scope of this
study is limited such that the students will be able to achieve these results within the period of
the REU experience and present their findings by its completion.
Faculty Mentor:
Vasile Nistor