Cardiopulmonary functional status assessment via metabolic response detection by implantable cardiac device
First Claim
Patent Images
1. An implantable medical device, comprising:
- a controller;
one or more sensing/pacing channels, wherein the controller is programmed to control the delivery of pacing pulses in accordance with an atrial-triggered mode such that a ventricular pace is delivered upon expiration of an escape interval designated as the AV delay interval;
a minute ventilation sensor interfaced to the controller;
an activity level sensor interfaced to the controller for measuring a parameter related to a patient'"'"'s level of physical activity;
wherein the controller is programmed to construct a historical record of activity level versus minute ventilation, referred to as a minute ventilation response profile;
wherein the controller is further programmed to monitor a patient'"'"'s cardiopulmonary functional status by computing a minute ventilation response slope from the minute ventilation response profile, defined as the ratio of an incremental change in minute ventilation to an incremental change in measured activity level, and compare the minute ventilation response slope to a specified limit value; and
,wherein the controller is further programmed to decrease the AV delay interval upon detecting that the patient'"'"'s minute ventilation response slope has worsened to a specified extent.
1 Assignment
0 Petitions
Accused Products
Abstract
An implantable cardiac device is configured and programmed to assess a patient'"'"'s cardiopulmonary function by evaluating the patient'"'"'s minute ventilation response. Such evaluation may be performed by computing a minute ventilation response slope, defined as the ratio of an incremental change in minute ventilation to an incremental change in measured activity level. The minute ventilation response slope may then be compared with a normal range to assess the patient'"'"'s functional status.
-
Citations
18 Claims
-
1. An implantable medical device, comprising:
-
a controller; one or more sensing/pacing channels, wherein the controller is programmed to control the delivery of pacing pulses in accordance with an atrial-triggered mode such that a ventricular pace is delivered upon expiration of an escape interval designated as the AV delay interval; a minute ventilation sensor interfaced to the controller; an activity level sensor interfaced to the controller for measuring a parameter related to a patient'"'"'s level of physical activity; wherein the controller is programmed to construct a historical record of activity level versus minute ventilation, referred to as a minute ventilation response profile; wherein the controller is further programmed to monitor a patient'"'"'s cardiopulmonary functional status by computing a minute ventilation response slope from the minute ventilation response profile, defined as the ratio of an incremental change in minute ventilation to an incremental change in measured activity level, and compare the minute ventilation response slope to a specified limit value; and
,wherein the controller is further programmed to decrease the AV delay interval upon detecting that the patient'"'"'s minute ventilation response slope has worsened to a specified extent. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method for operating an implantable medical device, comprising:
-
delivering pacing pulses in accordance with an atrial-triggered mode such that a ventricular pace is delivered upon expiration of an escape interval designated as the AV delay interval; measuring a parameter related to a patient'"'"'s level of physical activity; measuring a patient'"'"'s minute ventilation; constructing a historical record of activity level versus minute ventilation, referred to as a minute ventilation response profile; monitoring a patient'"'"'s cardiopulmonary functional status by computing a minute ventilation response slope from the minute ventilation response profile, defined as the ratio of an incremental change in minute ventilation to an incremental change in measured activity level, and comparing the minute ventilation response slope to a specified limit value; and
,decreasing the AV delay interval upon detecting that the patient'"'"'s minute ventilation response slope has worsened to a specified extent. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
-
Specification