Baroreflex modulation based on monitored cardiovascular parameter

Abstract

The present invention is a system for providing baroreceptor stimulation comprising, a sensor to sense a physiologic parameter and provide a signal indicative of the physiologic parameter, a baroreceptor activation device, which includes, a pulse generator to intermittently generate a stimulation signal to provide baroreceptor stimulation for a baroreflex therapy, and a control system to adjust the stimulation signal based on the signal indicative of the physiologic parameter such that the stimulation signal provides a desired baroreceptor stimulation corresponding to a desired physiologic parameter.

1 . A system for providing baroreflex stimulation, comprising:
 a heart rate monitor to sense a heart rate and provide a signal indicative of the heart rate; and   a baroreflex stimulator, including:
 a pulse generator to chronically deliver an efficacious intermittent baroreflex stimulation, 
 wherein the pulse generator is programmed to generate a stimulation signal in a recurring succession of stimulation cycles to provide the efficacious intermittent baroreflex stimulation, 
 wherein the stimulation signal is generated for a portion of each stimulation cycle and is not generated for an other portion of each stimulation cycle; and 
 wherein the efficacious intermittent baroreflex stimulation is associated with a programmed target heart rate change between a first heart rate during the portion of each stimulation cycle when the stimulation signal is generated and a second heart rate during the other portion of each stimulation cycle when the stimulation signal is not generated; and 
 a modulator to adjust the stimulation signal based on the signal indicative of the heart rate such that the stimulation signal results in the target heart rate change between the first heart rate and the second heart rate to maintain efficacy. 
   
     
     
         2 . The system of  claim 1 , wherein the target heart rate change includes a percentage of a heart rate during a time without baroreflex stimulation. 
     
     
         3 . The system of  claim 1 , wherein the modulator is adapted to adjust a signal characteristic of the stimulation signal, wherein the signal characteristic is selected from a group consisting of: an amplitude, a frequency, a burst frequency, a pulse width, and a duty cycle. 
     
     
         4 . The system of  claim 1 , wherein the modulator is adapted to adjust any combination of at least two stimulation signal attributes from a group of stimulation signal attributes consisting of: an amplitude, a frequency, a burst frequency, a pulse width, and a duty cycle. 
     
     
         5 . The system of  claim 1 , wherein the stimulation signal is generated at a periodic interval. 
     
     
         6 . The system of  claim 1 , wherein the stimulation signal is generated at an interval other than a periodic interval. 
     
     
         7 . A system for providing baroreflex stimulation, comprising:
 a baroreflex stimulator, including:
 a pulse generator to chronically deliver an efficacious intermittent baroreflex stimulation, the pulse generator to generate a stimulation signal in a recurring succession of stimulation cycles to provide the intermittent baroreflex stimulation, each stimulation cycle having at least a stimulation portion and a non-stimulation portion, wherein the efficacious intermittent baroreflex stimulation for the programmed baroreflex therapy is associated with a target change between a first value for a cardiovascular parameter during the stimulation portion of each cycle and a second value for the cardiovascular parameter during the non-stimulation portion of each cycle; and 
 a modulator to adjust the stimulation signal; 
   a cardiovascular parameter monitor to monitor the cardiovascular parameter and provide a first signal indicative of the cardiovascular parameter during the stimulation portion and a second signal indicative of the cardiovascular parameter during the non-stimulation portion; and   a comparator to provide a detected change for the cardiovascular parameter based on the first and second signals, and to provide a therapy control signal based on the target change for the cardiovascular parameter and the detected change to maintain efficacy of the intermittent baroreflex stimulation.   
     
     
         8 . The system of  claim 7 , wherein the modulator is adapted to adjust at least one stimulation signal attribute from a group of stimulation signal attributes consisting of: an amplitude, a frequency, a burst frequency, and a pulse width. 
     
     
         9 . The system of  claim 7 , wherein the cardiovascular parameter monitor is adapted to monitor a parameter selected from the group consisting of: heart rate, blood pressure, respiration rate, a surrogate parameter for heart rate that increases and decreases with the heart rate, a percent change for the cardiovascular parameter when influenced by the baroreflex stimulation and a quantitative change associated with the cardiovascular parameter when influenced by the baroreflex stimulation. 
     
     
         10 . The system of  claim 7 , wherein the target change includes a percent change. 
     
     
         11 . The system of  claim 7 , wherein the target change includes a quantitative change. 
     
     
         12 . The system of  claim 7 , wherein the stimulation signal is generated in the recurring succession of stimulation portions and non-stimulation cycles at a periodic interval. 
     
     
         13 . The system of  claim 7 , wherein the stimulation signal is generated in the recurring succession of stimulation portions and non-stimulation cycles at an interval other than a periodic interval. 
     
     
         14 . A baroreflex stimulator, comprising:
 means for chronically providing efficacious intermittent baroreflex stimulation, including means for generating a stimulation signal in a recurring succession of stimulation cycles having at least a stimulation portion and a non-stimulation portion, wherein an efficacy of the chronic intermittent baroreflex stimulation is associated with a target feedback change for a cardiovascular feedback parameter;   means for comparing a first value for the cardiovascular feedback parameter for the stimulation portion of the cycles to a second value for the non-stimulation portion of the cycles to provide a detected feedback change;   means for comparing the detected feedback change to the target feedback change to provide a comparison result; and   means for adjusting the baroreflex stimulation based on the comparison result to maintain the efficacy of the chronic intermittent baroreflex stimulation.   
     
     
         15 . The baroreflex stimulator of  claim 14 , wherein the means for comparing includes means for comparing a first heart rate value for the stimulation portion to a second heart rate value for the non-stimulation portion. 
     
     
         16 . The baroreflex stimulator of  claim 14 , further comprising means for programming the target feedback change. 
     
     
         17 . A method, comprising:
 chronically providing efficacious intermittent baroreflex stimulation, including generating a stimulation signal in a recurring succession of stimulation cycles, and an efficacy of the chronic intermittent baroreflex stimulation is associated with a target feedback change for a cardiovascular feedback parameter;   wherein generating the stimulation signal includes generating the stimulation signal for a portion of each stimulation cycle and not generating the stimulation signal for an other portion of each stimulation cycle;   comparing a first value for the cardiovascular feedback parameter corresponding to the portion of each cycle when the stimulation cycle is generated and a second value corresponding to the other portion of each cycle when the stimulation cycle is not generated to provide a detected feedback change;   comparing the detected feedback change to the target feedback change to provide a comparison result; and   adjusting the baroreflex stimulation based on the comparison result to maintain the efficacy of the efficacious intermittent baroreflex stimulation.   
     
     
         18 . The method of  claim 17 , further comprising programming the-target feedback change for use in comparing the detected feedback change to the target feedback change. 
     
     
         19 . The method of  claim 18 , wherein programming the target feedback change includes programming a percent change. 
     
     
         20 . The method of  claim 18 , wherein programming the desired feedback change includes programming a quantitative value change. 
     
     
         21 . The method of  claim 17 , wherein the at least one cardiovascular feedback parameter is selected from the group consisting of, heart rate, blood pressure and respiration. 
     
     
         22 . The method of  claim 17 , wherein adjusting the baroreflex stimulation includes adjusting a signal characteristic of a baroreflex signal used to provide the baroreflex stimulation wherein the signal characteristic is selected from the group consisting of: amplitude, frequency, burst frequency, pulse width and a duty cycle. 
     
     
         23 . The method of  claim 17 , wherein generating the stimulation signal in the recurring succession of stimulation cycles includes generating the stimulation signal at a periodic interval. 
     
     
         24 . The method of  claim 17 , wherein generating the stimulation signal in the recurring succession of stimulation cycles includes generating the stimulation signal at an interval other than a periodic interval. 
     
     
         25 . A system for providing baroreceptor stimulation comprising:
 a sensor to sense a physiologic parameter and provide a signal indicative of the physiologic parameter; and   a baroreceptor activation device, including:
 a pulse generator to chronically deliver an efficacious intermittent baroreceptor stimulation, 
 wherein the pulse generator is programmed to generate a stimulation signal in a recurring succession of stimulation cycles to provide the intermittent baroreceptor stimulation, 
 wherein the stimulation signal is generated for a portion of each stimulation cycle and is not generated for an other portion of each stimulation cycle; and 
 wherein the efficacious intermittent baroreceptor stimulation is associated with a predetermined target physiologic parameter change between a first physiologic parameter value during the portion of each stimulation cycle when the stimulation signal is generated and a second physiologic parameter value during the other portion of each stimulation cycle when the stimulation signal is not generated; and 
   a control system to adjust the stimulation signal based on the signal indicative of the physiologic parameter such that the stimulation signal results in the target physiologic parameter change between the first physiologic parameter value and the second physiologic parameter value to maintain efficacy.   
     
     
         26 . A system for providing baroreceptor stimulation, comprising:
 a baroreceptor activation device including:
 a pulse generator to deliver a chronic, efficacious intermittent baroreceptor stimulation, the pulse generator to generate a stimulation signal in a recurring succession of stimulation cycles to provide the intermittent baroreceptor stimulation each stimulation cycle having at least a stimulation portion and a non-stimulation portion, wherein the efficacious intermittent baroreceptor stimulation is associated with a target change between a first value for a physiologic parameter during the stimulation portion of each cycle and a second value for the physiologic parameter during a non-stimulation portion of each cycle; and 
 a modulator to adjust the stimulation signal; 
   a sensor to monitor the physiologic parameter and provide a first signal indicative of the physiologic parameter during the stimulation portion and a second signal indicative of the physiologic parameter during the non-stimulation portion;   a comparator to provide a detected change for the physiologic parameter based on the first and second signals, and to provide a therapy control signal based on the target change for the physiologic parameter and the detected change to maintain efficacy of intermittent baroreceptor stimulation.   
     
     
         27 . A baroreceptor stimulator, comprising
 means for chronically providing efficacious intermittent baroreceptor stimulation that includes means for generating a stimulation signal in a recurring succession of stimulation cycles having at least a stimulation portion and a non-stimulation portion, wherein an efficacy of the chronic intermittent baroreceptor stimulation is associated with a target feedback change for a physiologic parameter;   means for comparing a first value for the physiologic parameter for the stimulation portion of the cycles to a second value for the non-stimulation portion of the cycles to provide a detected change in the physiologic parameter;   means for comparing the detected physiologic parameter change to the target physiologic parameter change to provide a comparison result; and   means for adjusting the baroreceptor stimulation based on the comparison result to maintain the efficacy of the chronic intermittent baroreceptor stimulation.   
     
     
         28 . A method, comprising:
 chronically providing efficacious intermittent baroreceptor stimulation, including generating a stimulation signal in a recurring succession of stimulation cycles, and an efficacy of the chronic intermittent baroreceptor stimulation is associated with a target feedback change for a physiologic parameter;   wherein generating the stimulation signal includes generating the stimulation signal for a portion of each stimulation cycle and not generating the stimulation signal for an other portion of each stimulation cycle;   comparing a first value for the physiologic parameter corresponding to the portion of each cycle when the stimulation cycle is generated and a second value corresponding to the other portion of each cycle when the stimulation cycle is not generated to provide a detected physiologic parameter change;   comparing the detected physiologic parameter change to the target physiologic parameter change to provide a comparison result; and   
       adjusting the baroreceptor stimulation based on the comparison result to maintain the efficacy of the efficacious intermittent baroreceptor stimulation.