# US 6,377,851 B1 · Implantable cardiac stimulation device and method for optimizing sensing performance during rate adaptive bradycardia pacing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,377,851 B1 - Document ID: US6377851B1 - Status: Granted - Kind: B1 - Application number: 09/484,868 - Filed: 2000-01-18 - Granted: 2002-04-23 - Earliest claimed: 1999-12-17 - Assignees: Pacesetter, Inc. - Inventors: Mae-Mae Shieh; Jim C. Chen; Anthony Mo; Eric S. Fain - Web page: https://patentgrep.com/patent/US6377851B1 ## CPC - A61N 1/362: Heart stimulators (heart defibrillators A61N1/39) - A61N 1/39622: {Pacing therapy} - A61N 1/37: Monitoring; Protecting - A61N 1/3956: {Implantable devices for applying electric shocks to the heart, e.g. for cardioversion} - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) ## Abstract An implantable cardiac stimulation device including a ventricular defibrillator and a rate adaptive cardiac pacer automatically adjusts post-pacing sensing parameters dependent upon pacing rate. The device includes a pulse generator that applies stimulation pulses to a heart at a calculated variable stimulation rate as a function of physiologic demand. A sensing circuit senses ventricular activity of the heart responsive to a plurality of sensing parameters including post-pace sensing parameters and a processor adjusts the post-pace sensing parameters responsive to the selected pacing rate. ## Claims ### Claim 1 An implantable cardiac stimulation device including a ventricular defibrillator and a rate adaptive cardiac pacer comprising: pulse generating means for applying stimulation pulses to a patient's heart at a variable stimulation rate that is a function of a sensed physiologic demand; sensing means for sensing ventricular activity of the heart responsive to a plurality of sensing parameters including post-stimulation sensing parameters including an initial sensing threshold; and adjusting means for adjusting the initial sensing threshold responsive to a calculated stimulation rate. ### Claim 2 (depends on 1) The device of claim 1 further including processing means for determining the post-stimulation sensing parameters responsive to the calculated stimulation rate. ### Claim 3 (depends on 1) The device of claim 1 wherein the device includes a look-up table including the post-stimulation sensing parameters versus stimulation rate for adjusting the post-stimulation sensing parameters responsive to the calculated stimulation rate. ### Claim 4 (depends on 3) The device of claim 3 further including processing means for providing the look-up table with the post-stimulation sensing parameters versus stimulation rate. ### Claim 5 (depends on 4) The device of claim 4 wherein the processing means provides the look-up table with the post-stimulation sensing parameters versus stimulation rate based upon fixed criteria. ### Claim 6 (depends on 4) The device of claim 4 wherein the processing means provides the look-up table with the post-stimulation sensing parameters versus stimulation rate based upon selectable criteria. ### Claim 7 An implantable cardiac stimulation device including a ventricular defibrillator and a cardiac pacer comprising: a pulse generator that applies stimulation pulses to a heart at a variable stimulation rate; a sensing circuit that senses ventricular activity of the heart responsive to a plurality of sensing parameters including post-stimulation sensing parameters; a processor that adjusts the post-stimulation sensing parameters responsive to a calculated stimulation rate; and wherein the sensing circuit has an initial sensing threshold, wherein the initial sensing threshold is one of the post-stimulation sensing parameters and wherein the processor adjusts the initial sensing threshold responsive to the calculated stimulation rate. ### Claim 8 (depends on 7) The device of claim 7 wherein the processor is programmed to determine the post-stimulation sensing parameters responsive to the calculated stimulation rate. ### Claim 9 (depends on 7) The device of claim 7 further including a memory having a look-up table including the post-stimulation sensing parameters versus stimulation rate. ### Claim 10 (depends on 9) The device of claim 9 wherein the processor is programmed to provide the look-up table with the post-stimulation sensing parameters versus stimulation rate. ### Claim 11 (depends on 10) The device of claim 10 wherein the processor is programmed to provide the look-up table with the post-stimulation sensing parameters versus stimulation rate based upon fixed criteria. ### Claim 12 (depends on 11) The device of claim 11 wherein the processor is programmed to provide the look-up table with the post-stimulation sensing parameters versus stimulation rate based upon selectable criteria. ### Claim 13 In an implantable stimulation device including a ventricular defibrillator and a rate adaptive cardiac pacer, a method of applying stimulation pulses to a heart and sensing ventricular activity after applying a stimulation pulse including the steps of: applying stimulation pulses to a heart at a stimulation rate that varies as a function of physiologic demand; sensing ventricular activity of the heart responsive to a plurality of sensing parameters including post-stimulation sensing parameters; and adjusting one of the post-stimulation sensing parameters comprising an initial sensing threshold responsive to a calculated stimulation rate. ### Claim 14 (depends on 13) The method of claim 13 wherein one of the post-stimulation sensing parameters is an initial sensing threshold and wherein the adjusting step includes adjusting the initial sensing threshold responsive to the calculated stimulation rate. ### Claim 15 (depends on 13) The method of claim 13 wherein the sensing step includes decreasing a sensing threshold a delay time after applying a stimulation pulse, wherein the delay time is one of the post-stimulation sensing parameters, and wherein the adjusting step includes adjusting the delay time responsive to the calculated stimulation rate. ### Claim 16 (depends on 13) The method of claim 13 further including the step of determining the post-stimulation sensing parameters prior to calculating the selected stimulation rate. ### Claim 17 (depends on 13) The method of claim 13 including the further step of providing a look-up table including the post-stimulation sensing parameters versus stimulation rate and wherein the adjusting step includes obtaining the post-stimulation sensing parameters from the look-up table responsive to the calculated stimulation rate. ### Claim 18 (depends on 17) The method of claim 17 including the further step of providing the look-up table with the post-stimulation sensing parameters versus stimulation rate. ### Claim 19 (depends on 18) The method of claim 18 wherein the step of providing the look-up table with the post-stimulation sensing parameters versus stimulation rate is performed based upon fixed criteria. ### Claim 20 (depends on 18) The method of claim 18 wherein the step of providing the look-up table with the post-stimulation sensing parameters versus stimulation rate is performed based upon selectable criteria. ### Claim 21 An implantable cardiac stimulation device including a ventricular defibrillator and a rate adaptive cardiac pacer comprising: pulse generating means for applying stimulation pulses to a patient's heart at a variable stimulation rate that is a function of a sensed physiologic demand; sensing means for sensing ventricular activity of the heart responsive to a plurality of sensing parameters including post-stimulation sensing parameters including a decreasing sensing threshold which begins decreasing a delay time after application of a stimulation pulse; and adjusting means for adjusting the delay time responsive to the calculated stimulation rate. ### Claim 22 An implantable cardiac stimulation device including a ventricular defibrillator and a cardiac pacer comprising: a pulse generator that applies stimulation pulses to a heart at a variable stimulation rate; a sensing circuit that senses ventricular activity of the heart responsive to a plurality of sensing parameters including post-stimulation sensing parameters; a processor that adjusts the post-stimulation sensing parameters responsive to a calculated stimulation rate; and wherein the sensing circuit has a decreasing sensing threshold which begins decreasing a delay time after application of a stimulation pulse, wherein the delay time is one of the post-stimulation sensing parameters, and wherein the process adjusts the delay time responsive to the calculated stimulation rate. ### Claim 23 In an implantable stimulation device including a ventricular defibrillator and a rate adaptive cardiac pacer, a method of applying stimulation pulses to a heart and sensing ventricular activity after applying a stimulation pulse including the steps of: applying stimulation pulses to a heart at a stimulation rate that varies as a function of physiologic demand; sensing ventricular activity of the heart by setting a sensing threshold and decreasing the sensing threshold a delay time after applying a stimulation pulse; and adjusting the delay time responsive to a calculated stimulation rate.