Patent ID: 8538526

Claim:
A pacemaker, comprising: pacing circuitry for generating pacing pulses to be delivered to one or more atrial or ventricular sites; a minute ventilation sensor for measuring minute ventilation (MV); an activity level sensor for measuring activity level; and, a controller for controlling the delivery of pacing pulses in accordance with a programmed mode, wherein the controller is further programmed to: deliver pacing pulses at a rate determined by a rate-adaptive algorithm as a function of the sensed minute ventilation, termed the sensor-indicated rate (SIR); compute the sensor-indicated rate by mapping a measured ventilation value equaling a specified baseline minute ventilation value (BMV) to a specified minimum pacing rate, termed the lower rate limit (LRL), and mapping a measured minute ventilation value greater than the baseline minute ventilation value to a pacing rate calculated as the LRL added to the amount by which the measured minute ventilation value exceeds the baseline minute ventilation value multiplied by a rate response factor; and, enter a parameter adjustment mode for calculating the value of the rate response factor by: 1) monitoring the measured activity level, 2) when the measured activity level is maintained within a specified target activity level range for a specified length of time, measuring a corresponding target minute ventilation value (TMV), and 3) calculating the rate response factor (RF) as: RF =( THR−LRL )/( TMV−BMV ) where the target heart rate THR is a specified value corresponding to a desired pacing rate for the target activity level range and wherein the target activity level range is selected such that the TMV is less than a minute ventilation value that is mapped by the rate-adaptive algorithm to a maximum sensor-indicated rate.