Abstract: A plurality of phases of sniff operations are performed for detecting wake-up signals being received by an implantable medical device (IMD), including a phase that performs a staged detection of whether the integrated frequency deviation of a received signal is outside of an expected frequency deviation range, where sniff operations are aborted if the integrated frequency deviation of the received signal falls outside of corresponding high and low thresholds in any stage, wherein the difference between the high and low thresholds tightens with each subsequent stage and an average frequency deviation over all completed stages are used in the calculations. One phase of sniff operations includes a dual frequency modulation (FM) detector including a first FM detector that introduces a small delay in a received signal providing an average frequency estimate and a second FM detector having a larger delay that is adjusted based on the estimated average frequency.

Abstract: A low power method and apparatus for detecting wake-up signals in sniff processing performed in an implantable medical device (IMD) using a staged detection of RF energy in signals received in order to conserve current consumption. Incoming signals are monitored in a plurality of detection stages which each incrementally increase the accuracy of detecting whether the received signal is a wake-up communication signal. A desired number of stages of signal quantity measurements are performed such that a combined signal quantity is calculated by updating the signal quantity measurements performed in prior stages with signal quantity measurements performed at each stage. The combined signal quantity of the received communication signal is compared at each detection stage against a corresponding threshold value for that stage. The staged detection process aborts sniff processing if the combined signal quantity fails to meet the corresponding threshold value for that stage.

Abstract: A low power multiple channel receiver mixing architecture for detecting wake-up signals over multiple communication channels in sniff processing performed in an implantable medical device (IMD). The architecture includes a direct conversion real receiver configured to scan a selected center channel and a Weaver receiver configured in parallel to the direct conversion real receiver to simultaneously scan side channels, together simultaneously detecting whether a wake-up signal is being received over the center and side channels with minimal power consumption. The architecture further utilizes a falsing protection algorithm that reduces power consumption during sniff operations by inhibiting the sniffing of channels likely to provide a false indication of a wake-up signal based the presence of unwanted signals on those channels.

Abstract: A plurality of phases of sniff operations are performed for detecting wake-up signals being received by an implantable medical device (IMD), including a phase that performs a staged detection of whether the integrated frequency deviation of a received signal is outside of an expected frequency deviation range, where sniff operations are aborted if the integrated frequency deviation of the received signal falls outside of corresponding high and low thresholds in any stage, wherein the difference between the high and low thresholds tightens with each subsequent stage and an average frequency deviation over all completed stages are used in the calculations. One phase of sniff operations includes a dual frequency modulation (FM) detector including a first FM detector that introduces a small delay in a received signal providing an average frequency estimate and a second FM detector having a larger delay that is adjusted based on the estimated average frequency.

Abstract: A low power multiple channel receiver mixing architecture for detecting wake-up signals over multiple communication channles in sniff processing performed in an implantable medical device (IMD). The architecture includes a direct conversion real receiver configured to scan a selected center channel and a Weaver receiver configured in parallel to the direct conversion real receiver to simultaneously scan side channels, together simultaneously detecting whether a wake-up signal is being received over the center and side channels with minimal power consumption. The architecture further utilizes a falsing protection algorithm that reduces power consumption during sniff operations by inhibiting the sniffing of channels likely to provide a false indication of a wake-up signal based the presence of unwanted signals on those channels.

Abstract: A low power method and apparatus for detecting wake-up signals in sniff processing performed in an implantable medical device (IMD) using a staged detection of RF energy in signals received in order to conserve current consumption. Incoming signals are monitored in a plurality of detection stages which each incrementally increase the accuracy of detecting whether the received signal is a wake-up communication signal. A desired number of stages of signal quantity measurements are performed such that a combined signal quantity is calculated by updating the signal quantity measurements performed in prior stages with signal quantity measurements performed at each stage. The combined signal quantity of the received communication signal is compared at each detection stage against a corresponding threshold value for that stage. The staged detection process aborts sniff processing if the combined signal quantity fails to meet the corresponding threshold value for that stage.

Abstract: An integrator with a reset mechanism comprises an integration capacitor and a replacement integration capacitor, wherein the integration capacitor is replaced with the replacement integration capacitor during a reset operation. A method of resetting an integrator comprises temporarily removing an integration capacitor and replacing the integration capacitor with a reset capacitor during a reset operation of the integrator. The method may further comprise temporarily removing the integration capacitor and replacing it with a reset capacitor multiple times during a single reset operation of the integrator.

Abstract: A delta-sigma modulator comprising a number of integration stages and having a feed-forward path from a signal input section to the signal path prior to a final integration stage, so as to reduce processing in the majority of integration stages to error processing. A delta-sigma modulator with acceptable dynamic range and incomplete settling can be designed for audio applications using a ratio of gain bandwidth product to sampling frequency in terms of a resolution of the converter. Satisfying the criteria provided by the ratio reduces the gain bandwidth requirement below that previously used as acceptable values in data converter design.

Abstract: A delta-sigma modulator comprising a number of integration stages and having a feed-forward path from a signal input section to the signal path prior to a final integration stage, so as to reduce processing in the majority of integration stages to error processing. A delta-sigma modulator with acceptable dynamic range and incomplete settling can be designed for audio applications using a ratio of gain bandwidth product to sampling frequency in terms of a resolution of the converter. Satisfying the criteria provided by the ratio reduces the gain bandwidth requirement below that previously used as acceptable values in data converter design.