Receiver and digital demodulation circuitry for an external controller useable in an implantable medical device system

摘要

Receiver and digital demodulation circuitry for an external controller for communicating with an implantable medical device (IMD) is disclosed. A Digital Signal Processor (DSP) is used to sample received analog data transmitted from the IMD at a lower rate than would otherwise be required for the frequency components in the transmitted data by the Nyquist sampling criteria. To allow for this reduced sampling rate, the incoming data is shifted to a lower intermediate frequency using a switching circuit. The switching circuit receives a clock signal, which is preferably but not necessarily the same clock signal used by the DSP to sample the data. The switching circuit multiplies the received data with the clock signal to produce lower intermediate frequencies, which can then be adequately sampled at the DSP at the reduced sampling rate per the Nyquist sampling criteria.

主权项

1. An external controller for receiving wireless data from an implantable medical device, comprising:
an antenna configured to generate an analog AC signal in response to wireless data received from the implantable medical device, wherein the wireless data comprises at least one first frequency; an amplifier configured to amplify the analog AC signal; a switching circuit controlled by a digital reference signal of a second frequency, wherein the switching circuit is configured to invert the amplified analog AC signal when the digital reference signal changes state, thereby producing an intermediate frequency analog AC signal comprising at least one intermediate frequency; and an analog-to-digital (A/D) converter configured to sample the intermediate frequency analog AC signal using the digital reference signal, thereby producing digital samples.