Automatic selection of electrode vectors for assessing risk of heart failure decompensation events
First Claim
1. A method for determining a risk of a patient experiencing a heart failure decompensation event in the near future, the method comprising:
- storing, by a medical device implanted in the patient, an electrode vector parameter indicating an electrode vector of a plurality of electrode vectors, each of the electrode vectors being a different combination of electrodes;
using, by the medical device, a plurality of electrode vectors to generate a plurality of intrathoracic impedance measurements;
performing, by the medical device, a vector selection operation on a first recurring basis, wherein each time the medical device performs the vector selection operation, the medical device;
selects a given electrode vector from among the plurality of electrode vectors, the intrathoracic impedance measurements generated using the given electrode vector being at a current time likely to be more reliable than the intrathoracic impedance measurements generated using other ones of the electrode vectors for determining the risk of the patient experiencing the heart failure decompensation event in the near future;
causes a telemetry unit of the medical device to transmit a vector suggestion message to a programmer after the selection of the given electrode vector, the vector suggestion message specifying the selected electrode vector;
receives a selection message from the programmer in response to the vector suggestion message, the selection message specifying the selected electrode vector or another one of the electrode vectors; and
responsive to the selection message, updates the electrode vector parameter to indicate the electrode vector specified by the selection message;
performing, by the medical device, a risk assessment operation on a second recurring basis, wherein each time the medical device performs the risk assessment operation, the medical device determines the risk based at least in part on intrathoracic impedance measurements generated using the electrode vector indicated by the electrode vector parameter;
calculating, based on the intrathoracic impedance measurements generated using the electrode vector indicated by the electrode vector parameter, an initial risk score during the risk assessment operation, the risk score being correlated with a likelihood of the patient experiencing the heart failure decompensation event in the near future;
recalculating the risk score using one or more intrathoracic impedance measurements generated using electrode vectors other than the electrode vector indicated by the electrode vector parameter; and
responsive to determining that one of, but not both of, the initial risk score and the recalculated risk score exceeds a predetermined risk threshold, performing the vector selection operation.
1 Assignment
0 Petitions
Accused Products
Abstract
An implantable medical device (IMD) is implanted in a patient. The IMD uses a plurality of electrode vectors to generate intrathoracic impedance measurements. The intrathoracic impedance measurements can be indicative of amounts of intrathoracic fluid in the patient. An accumulation of intrathoracic fluid may indicate that the patient is at an increased risk of experiencing a heart failure event in the near future. The IMD performs a vector selection operation on a recurring basis. When the IMD performs the vector selection operation, the IMD uses impedance measurements to select one of the electrode vectors. The IMD can perform a risk assessment operation on another recurring basis. During performance of the risk assessment operation, the IMD uses impedance measurements of the selected electrode vector and/or other patient characteristics stored within the IMD to determine whether the patient is at an increased risk of experiencing a heart failure event.
52 Citations
15 Claims
-
1. A method for determining a risk of a patient experiencing a heart failure decompensation event in the near future, the method comprising:
-
storing, by a medical device implanted in the patient, an electrode vector parameter indicating an electrode vector of a plurality of electrode vectors, each of the electrode vectors being a different combination of electrodes; using, by the medical device, a plurality of electrode vectors to generate a plurality of intrathoracic impedance measurements; performing, by the medical device, a vector selection operation on a first recurring basis, wherein each time the medical device performs the vector selection operation, the medical device; selects a given electrode vector from among the plurality of electrode vectors, the intrathoracic impedance measurements generated using the given electrode vector being at a current time likely to be more reliable than the intrathoracic impedance measurements generated using other ones of the electrode vectors for determining the risk of the patient experiencing the heart failure decompensation event in the near future; causes a telemetry unit of the medical device to transmit a vector suggestion message to a programmer after the selection of the given electrode vector, the vector suggestion message specifying the selected electrode vector; receives a selection message from the programmer in response to the vector suggestion message, the selection message specifying the selected electrode vector or another one of the electrode vectors; and responsive to the selection message, updates the electrode vector parameter to indicate the electrode vector specified by the selection message; performing, by the medical device, a risk assessment operation on a second recurring basis, wherein each time the medical device performs the risk assessment operation, the medical device determines the risk based at least in part on intrathoracic impedance measurements generated using the electrode vector indicated by the electrode vector parameter; calculating, based on the intrathoracic impedance measurements generated using the electrode vector indicated by the electrode vector parameter, an initial risk score during the risk assessment operation, the risk score being correlated with a likelihood of the patient experiencing the heart failure decompensation event in the near future; recalculating the risk score using one or more intrathoracic impedance measurements generated using electrode vectors other than the electrode vector indicated by the electrode vector parameter; and responsive to determining that one of, but not both of, the initial risk score and the recalculated risk score exceeds a predetermined risk threshold, performing the vector selection operation. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. An implantable medical device (IMD), comprising:
-
a plurality of electrodes; a memory storing an electrode vector parameter indicating an electrode vector of a plurality of electrode vectors, each of the electrode vectors being a different combination of the electrodes; a telemetry unit; and a processor configured to; use the plurality of electrode vectors to generate a plurality of intrathoracic impedance measurements; perform a vector selection operation on a first recurring basis, wherein each time the processor performs the vector selection operation, the processor; selects a given electrode vector from among the plurality of electrode vectors, the intrathoracic impedance measurements generated using the given electrode vector being at a current time likely to be more reliable than the intrathoracic impedance measurements generated using other ones of the electrode vectors for determining a risk of a patient experiencing a heart failure decompensation event in the near future; causes the telemetry unit to transmit a vector suggestion message to a programmer after the selection of the given electrode vector, the vector suggestion message specifying the selected electrode vector, wherein the telemetry unit receives a selection message from the programmer in response to the vector suggestion message, the selection message specifying the selected electrode vector or another one of the electrode vectors; responsive to the selection message, updates the electrode vector parameter to indicate the electrode vector specified by the selection message; and perform a risk assessment operation on a second recurring basis, wherein each time the processor performs the risk assessment operation, the processor determines the risk based at least in part on intrathoracic impedance measurements generated using the electrode vector indicated by the electrode vector parameter, wherein the processor is further configured to; calculate, based on the intrathoracic impedance measurements generated using the electrode vector indicated by the electrode vector parameter, an initial risk score during the risk assessment operation, the risk score being correlated with a likelihood of the patient experiencing the heart failure decompensation event in the near future; recalculate the risk score using one or more intrathoracic impedance measurements generated using electrode vectors other than the electrode vector indicated by the electrode vector parameter; and responsive to determining that one of, but not both of, the initial risk score and the recalculated risk score exceeds a predetermined risk threshold, perform the vector selection operation. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
-
15. A non-transitory computer readable medium that stores instructions, execution of the instructions causing an implantable medical device (IMD) to:
-
store an electrode vector parameter indicating an electrode vector of a plurality of electrode vectors, each of the electrode vectors being a different combination of electrodes; use the plurality of electrode vectors to generate a plurality of intrathoracic impedance measurements; perform a vector selection operation on a first recurring basis, wherein each time the medical device performs the vector selection operation, the medical device; selects a given electrode vector from among the plurality of electrode vectors, the intrathoracic impedance measurements generated using the given electrode vector being at a current time likely to be more reliable than the intrathoracic impedance measurements generated using other ones of the electrode vectors for determining a risk of a patient experiencing a heart failure decompensation event in the near future; causes a telemetry unit of the medical device to transmit a vector suggestion message to a programmer after the selection of the given electrode vector, the vector suggestion message specifying the selected electrode vector; receives a selection message from the programmer in response to the vector suggestion message, the selection message specifying the selected electrode vector or another one of the electrode vectors; and responsive to the selection message, updates the electrode vector parameter to indicate the electrode vector specified by the selection message; perform a risk assessment operation on a second recurring basis, wherein each time the medical device performs the risk assessment operation, the medical device determines the risk based at least in part on intrathoracic impedance measurements generated using the electrode vector indicated by the electrode vector parameter; calculate, based on the intrathoracic impedance measurements generated using the electrode vector indicated by the electrode vector parameter, an initial risk score during the risk assessment operation, the risk score being correlated with a likelihood of the patient experiencing the heart failure decompensation event in the near future; recalculate the risk score using one or more intrathoracic impedance measurements generated using electrode vectors other than the electrode vector indicated by the electrode vector parameter; and responsive to determining that one of, but not both of, the initial risk score and the recalculated risk score exceeds a predetermined risk threshold, perform the vector selection operation.
-
Specification