Mechanical Engineering

Associate professor

Murakoshi, Michio

Building bridges between people and medical care through mechanical engineering

How can we detect hearing loss in newborn babies?

In our laboratory, based on knowledge of mechanical engineering and auditory mechanics, we would like to contribute to the area of human health by developing unique and effective diagnostic systems. Hearing disorders are reported to occur in about 1-2 out of every 1,000 neonates. Early diagnosis and treatment of such disorders in neonates is highly effective for realization of linguistic competence and intellectual development. Current procedures used for hearing screening programs include otoacoustic emissions (OAEs) and automated auditory brainstem response (ABR). Their diagnostic sensitivities have been reported to be high. Unfortunately, however, it is impossible to diagnose the type of hearing loss such as conductive hearing loss and sensorineural hearing loss using these methods. Therefore, we are focusing on middle ear dynamics and are attempting to develop a non-invasive diagnostic system for such diseases based on the techniques of acoustical engineering. Furthermore, we are focused on applying this system to neonates for early detection of hearing dysfunction.

Diagnostic device for middle ear dynamics in newborns.

The motor protein hidden in your inner ear

Outer hair cells in the human ear.

As many as 12,000 sensory cells called outer hair cells (OHCs) exist in the mammalian inner ear. There are three rows of such cells, and they amplify the hearing sensitivity by several tens of thousands of times by moving in synchronicity with the sound delivered in the inner ear. The origin of this OHC motility is believed to be a motor protein expressed in the plasma membrane of the OHCs. This motor protein has a diameter of one-thousandth of a hair width and is thought to transform its own size. In the laboratory, we are attempting to elucidate this transformation mechanism and to develop a new technology for manipulating this motor protein.

Profile

Mechanical Engineering

Associate professor

Murakoshi, Michio

Dr. Michio Murakoshi obtained his PhD degree at Tohoku University in 2008. Immediately after that, he became an engineer in A&D Company Limited, Tokyo, Japan, which offers a wide and diverse range of measurement, weighing and medical equipment. From 2009, he started working as Assistant Professor in the Department of Bioengineering and Robotics at Tohoku University. He was promoted to Associate Professor in 2013 in the Department of Mechanical Engineering at Kagoshima University. His research interests encompass both basic research into hearing mechanics and the application of research findings in the development of hearing diagnostic devices and biomicromachines. His special field of study includes system dynamics and biomedical engineering.

Message for Students

Performing hearing tests on adults is straight forward because you can ask if they can hear a sound or not. However this is not the case with infants. If they have some trouble hearing, how can we find out what the problem is? The research interests of our laboratory encompass both basic research into hearing mechanics and the application of our findings in the development of hearing diagnostic devices and biomicromachines such as the development of a diagnostic system for newborn hearing screening, the numerical analysis of the hearing organ at the nanoscale level, the structural analysis of molecular motor expressed in the plasma membrane by atomic force microscopy and the development of an implantable drug delivery system for the treatment of hereditary hearing loss.

Other Researcher