Dynamic control of sensitivity associated with detecting R-waves

A device capable of dynamically controlling sensitivity associated with detecting R-waves, the device comprising:

• a plurality of electrodes;
• a sense amplifier configured to be coupled to a pair of the electrodes and configured to output an analog signal indicative of cardiac electrical activity;
• an analog-to-digital converter (ADC) configured to convert the analog signal indicative of cardiac electrical activity to a digital signal indicative of cardiac electrical activity;
• adjustable gain circuitry downstream of the ADC and configured to adjust a gain applied to the digital signal indicative of cardiac electrical activity;
• a digital comparator downstream of the adjustable gain circuitry and configured to detect R-waves by comparing the digital signal indicative of cardiac electrical activity to a fixed detection threshold to thereby detect threshold crossings that corresponds to R-waves;
• and
• a controller configured to selectively adjust the gain applied by the adjustable gain circuitry to thereby selectively adjust a sensitivity associated with the comparator detecting R-waves by detecting threshold crossings that corresponds to R-waves;
• wherein the ADC, the adjustable gain circuitry downstream of the ADC, and the digital comparator downstream of the adjustable gain circuitry, are all included in a feedforward signal path;
• and
• wherein the adjustable gain circuitry, for which gain is selectively adjusted by the controller, is between the ADC and the digital comparator within the feedforward signal path, downstream of the ADC and upstream of the digital comparator.

A device capable of detecting R-waves, the device comprising:

• a plurality of electrodes;
• a sense amplifier configured to be coupled to a pair of the electrodes and configured to output an analog signal indicative of cardiac electrical activity;
• converter and adjustable gain circuitry configured to convert the analog signal indicative of cardiac electrical activity to a digital signal indicative of cardiac electrical activity and to selectively adjust at least one adjustable gain factor in the digital domain;
• digital comparator circuitry configured to detect R-waves by comparing the digital signal indicative of cardiac electrical activity to a fixed detection threshold to thereby detect threshold crossings that corresponds to R-waves;
• and
• a controller configured to selectively adjust the at least one adjustable gain factor of the converter and adjustable gain circuitry to thereby selectively adjust a sensitivity associated with detecting R-waves;
• wherein the converter and adjustable gain circuitry, for which the at least one adjustable gain factor is adjusted in the digital domain by the controller, is within a feedforward path between the sense amplifier and the digital comparator circuitry, downstream of the sense amplifier and upstream of the digital comparator.