Method and apparatus for intra-body ultrasound communication

摘要

An intra-body ultrasonic signal can be converted into a first electrical signal, a local oscillator signal can be generated in an implantable system. The first electrical signal and the local oscillator signal can be mixed in an implantable system, such as to generate a demodulated signal, processed, such as using a filter. The filtered, demodulated signal can be further processed, such as implantably determining a peak amplitude of the first portion of the demodulated signal received from the filter over a time interval, implantably generating a dynamic tracking threshold that starts at an amplitude proportional the first portion of the demodulated signal and exponentially decays over a time interval, and determining a noise floor in the absence of a received intra-body ultrasonic signal and implantably comparing the peak amplitude and the tracking threshold and generate the digital output based on the difference.

主权项

1. An implantable system, comprising:
an ultrasonic receiver circuit coupleable to an ultrasonic transducer, the ultrasonic receiver circuit configured to obtain from the ultrasonic transducer a first electrical signal representative of an ultrasonic communication signal transduced by the ultrasonic transducer, the ultrasonic receiver circuit comprising: a local oscillator circuit; a mixer circuit coupled to the local oscillator circuit, the mixer circuit configured to provide a second electrical signal representative of the ultrasonic communication signal using the first electrical signal and the local oscillator circuit; a pre-amplifier circuit coupled to the mixer circuit, the pre-amplifier circuit including at least one field-effect transistor (FET) configured to operate in a weak inversion mode; and an analog-to-digital converter circuit coupled to the mixer and configured to provide a digital representation of the second electrical signal.