A Novel Bone Conduction Implant - Analog Radio Frequency Data and Power Link Design

Paper in proceeding, 2012

Patients who are suffering from conductive hearing loss and single sided deafness cannot sometimes be rehabilitated by conventional air conduction hearing aids. Today, percutaneous Bone Anchored Hearing Aid (BAHA) is an important alternative for such patients. BAHA uses a titanium implant which penetrates the skin and can cause skin infection, skin redness and requires life-long commitment of care every day. A novel Bone Conduction Implant (BCI) is designed as an alternative to the percutaneous BAHA, because it leaves the skin intact. It comprises an external audio processor and an implanted unit called the BCI Bone Bridge. Sound is transmitted to the implant via an inductive radio frequency (RF) link through the intact skin using amplitude modulation. This paper presents an analog RF data and power link design as a first implementation for the BCI. The RF link is designed to operate in critical coupling to transmit maximum power to the implant. Maximum Power Output of the BCI was measured at 2 mm skin thickness and was found to be 105 dB relative to 1 µN at the transducer resonance frequency. This output force is fairly robust in 2 mm to 6 mm skin thickness range.