Systems and methods for sensing vector selection in an implantable medical device

A programmer for use with an implantable medical device (IMD), the IMD including or configured for attachment to electrodes for sensing cardiac signals, the programmer comprising telemetry circuitry for communicating with the IMD, a user interface for communicating with an operator, and operational circuitry configured to perform a method of selecting a sensing vector for the IMD, the method which the programmer is configured to perform comprising:

• X) directing the IMD to capture and transmit data related to a selected sensing vector, including the IMD identifying a set of detected events separated by intervals in the data from the selected sensing vector;
• Y) analyzing the transmitted data to determine if the selected sensing vector is well-suited for cardiac event detection;
• and:
• if the selected sensing vector is well suited for cardiac event detection, directing the IMD to use the selected sensing vector for cardiac event detection;
• or
• repeating X) and Y) with another sensing vector;
• wherein analyzing the transmitted data to determine if the selected sensing vector is well-suited is performed while the patient is experiencing a cardiac rate in a range having an upper limit and comprises:
• analyzing the set of detected events and the intervals separating the detected events and characterizing events as either Noise or QRS by:
• a) observing the interval before a given event and, if the interval is greater than a predetermined length, wherein the predetermined length is set to correspond to the upper limit of the cardiac rate range, characterizing the given event as QRS;
• otherwise,
• b) observing whether the interval before the given event and the interval before a preceding event are very similar and, if so, performing amplitude analysis to characterize the given event and the preceding event as either Noise or QRS;
• and
• c) if neither a) nor b) determining whether to characterize the given event as Noise or QRS by comparing the interval before the given event to the interval before the preceding event, and characterizing the given event as noise if the interval before the given event is the shorter of the two intervals:
• further wherein, if amplitude analysis is performed, either:
• i) the given event is characterized as Noise and the preceding event is characterized as QRS;
• or
• ii) the given event is characterized as QRS and the preceding event is characterized as Noise;
• further wherein, in b), if two intervals are equal, the two intervals are considered very similar.

An implantable medical device (IMD) including or configured for coupling to electrodes for sensing cardiac signals and operational circuitry coupled to the electrodes, the IMD adapted to define a plurality of sensing vectors for observing electrical activity of a patient's heart from implanted positions, the operational circuitry configured to perform a method of selecting a sensing vector for the IMD, the method comprising:

• X) capturing data related to a selected sensing vector;
• Y) analyzing the captured data for vector selection purposes to determine if the selected sensing vector is well-suited for cardiac event detection;
• if the selected sensing vector is well suited for cardiac event detection, using the selected sensing vector for cardiac event detection;
• or
• repeating X) and Y) with another sensing vector;
• wherein analyzing data related to the captured cardiac signal data for vector selection purposes is performed while the patient is experiencing a cardiac rate in a range having an upper limit and comprises:
• setting a detection threshold and identifying a set of events separated by intervals in the cardiac signal data;
• analyzing the set of events and characterizing events as either Noise or QRS by:
• a) observing the interval before a given event and, if the interval is greater than a predetermined length, characterizing the given event as QRS, the predetermined length being set to correspond to the upper limit of the cardiac rate range;
• otherwise,
• b) observing whether the interval before the given event and the interval before a preceding event are very similar and, if so, performing amplitude analysis to characterize the event and the preceding event as either Noise or QRS;
• and
• c) if neither a) nor b), determining whether to characterize the given event as Noise or QRS by comparing the interval before the given event to the interval before the preceding event to identify the shorter of the two intervals, and identifying the given event as Noise if the interval before the given event is the shorter of the two intervals:
• further wherein, if amplitude analysis is performed, either:
• i) the given event is characterized as Noise and the preceding event is characterized as QRS;
• or
• ii) the given event is characterized as QRS and the preceding event is characterized as Noise;
• still further wherein, in b), if the two intervals are equal, then the two intervals are observed to be very similar.