Bionic man

The international Lister Medal, one of the most prestigious honours a surgeon can receive, was won by Australia’s Graeme Clarke this week. We profile the man who made the ‘bionic ear’ a reality.

For 10 years, Graeme Clark had been working tirelessly to develop an implant that would help the deaf to hear. The theory made sense. The electronics had been developed, and the design was near finalised.

But there was one seemingly insurmountable hurdle: how to actually get the implant into the intricate spiral of the inner ear.

During one Melbourne summer in 1977, he took his young children to the beach to escape the heat. While they were playing in the shallows, Clark noticed a seashell lying on the ground – and that its helical structure was a crude replica of the human cochlea.

Inspiration hit. He pulled up some grass blades and experimented with teasing them into the shell’s opening. Owing to their flexible tips and stiff bases, the blades slid smoothly into the tightening spiral. It revealed a simple solution to a complex problem.

Rushing back to  the lab, he confirmed that wire electrodes following the same design as a grass blade would solve his problem. Designed with progressive stiffness, the electrodes could be made to travel the length of the cochlea, all the way to the nerve cells that code for speech.

This design is now the basis of the hugely successful cochlear implant, a small surgical implant that simulates hearing for the deaf by stimulation of the auditory nerve to reproduce speech. Today, more than 200,000 people have received cochlear implants in more than 100 countries.

Read more here Bionic man | COSMOS magazine.

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