Receiver With Dual Band Pass Filters and Demodulation Circuitry for an External Controller Useable in an Implantable Medical Device System
First Claim
1. An external controller for receiving wireless data from an implantable medical device, comprising:
- an antenna configured to generate a AC signal in response to wireless data from the implantable medical device;
an amplifier configured to amplify the AC signal;
a first band pass filter configured to receive the amplified AC signal, the first band pass filter centered at a first frequency;
a second band pass filter configured to receive the output of the first band pass filter, the second band pass filter centered at a second frequency; and
a comparator configured to receive the output of the second band pass filter, wherein the comparator outputs a square wave.
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Accused Products
Abstract
Receiver and demodulation circuitry for an external controller for an implantable medical device is disclosed. The circuitry comprises two high Quality-factor band pass filters (BFPs) connected in series. Each BFP is tuned to a different center frequency, such that these center frequencies are outside the band of frequencies transmitted form the IMD. The resulting frequency response is suitably wide to receive the band without attenuation, but sharply rejects noise outside of the band. The resulting filtered signal is input to a comparator to produce a square wave of the filtered signal, which maintains the frequencies of the received signal and is suitable for input to a digital input of a microcontroller in the external controller. Demodulation of the square wave occurs in the microcontroller, and involves assessing the time between transitions in the square wave. These transmission timings are compared to expected transition times for the logic states in the transmitted data. The results of these comparisons are stored and filtered to remove noise and to recover the transmitted data.
20 Citations
29 Claims
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1. An external controller for receiving wireless data from an implantable medical device, comprising:
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an antenna configured to generate a AC signal in response to wireless data from the implantable medical device; an amplifier configured to amplify the AC signal; a first band pass filter configured to receive the amplified AC signal, the first band pass filter centered at a first frequency; a second band pass filter configured to receive the output of the first band pass filter, the second band pass filter centered at a second frequency; and a comparator configured to receive the output of the second band pass filter, wherein the comparator outputs a square wave. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An external controller for receiving wireless data from an implantable medical device, comprising:
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receiver circuitry configured to receive wireless data from the implantable medical device, wherein the wireless data from the implantable medical device comprises at least two data frequencies, each data frequency indicative of a data state, wherein the receiver circuitry outputs a square wave comprised of the at least two frequencies; and a microcontroller configured to receive the square wave, wherein the microcontroller is configured to recover the data states by determining timings between transitions in the square wave. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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Specification