An electroacoustic recording device for wireless sensing of neural signals.

Elimination of wires connecting neural recording electrodes to external electronics is highly desired, particularly in survival animal studies, due to neural damage and the device failures caused by these wires. In this study, an electroacoustic device for sensing and wireless transmission of neural signals to an external unit is proposed and results from a prototype are presented. In this method, the neural signals modulate the acoustic pulse amplitudes generated by a small piezoelectric element that is implanted at the recording site. The acoustics waves are detected wirelessly outside the nervous system by another piezoelectric transducer and the neural signals are extracted by amplitude demodulation. To test the prototype, a sinusoidal signal with 100µVpp amplitude was applied in phosphate buffered saline to simulated neural signals and the external transducer was placed 10mm away from the recording element. The results show that a sinusoidal signal of the given amplitude could be wirelessly sensed and reconstructed with a signal-to-noise ratio of 14dB.