Rate responsive pacemaker and method for automatically initializing the same

Claim 2

A pacemaker system comprising a pacemaker including at least one sense amplifier, said system comprising: a. sensor means for sensing pacing parameters; and b. means for automatically initializing the sensitivity of said sense amplifiers to an optimized value via automatically optimizing a sensitivity threshold, including processor means for processing the sensed pacing parameters; c. said processor means including: i) means for periodically determining a sense ratio factor (SRF) according to the following equation: ##EQU10## where Recommended Safety Margin is calculated as follows: Recommended Safety Margin=(% Safety Margin+P %)/100, and Safety Margin and P are programmable values; and ii) means for determining said optimized sensitivity threshold (Recommended Sensitivity Threshold) by multiplying said SRF by a Programmed Threshold.

Claim 3

The pacemaker system as defined in claim 1, further including means for displaying an optimized sensitivity threshold parameter.

Claim 4

The pacemaker system as defined in claim 1, wherein a sensitivity threshold pacing parameter is set at an initialized value; and wherein said processor means further includes means for automatically initializing said sensitivity threshold parameter by setting it equal to an optimized sensitivity threshold parameter.

Claim 5

The pacemaker system as defined in claim 1, wherein the pacemaker system includes an implantable pacemaker for pacing a human heart, and an external programmer which communicates with said pacemaker and which allows a user to select the pacing parameter to be optimized.

Claim 6

The pacemaker system as defined in claim 4, wherein said processor means is at least partially located in said pacemaker.

Claim 7

The pacemaker system as defined in claim 4, wherein said processor means is at least partially located in said programmer.

Claim 8

A pacemaker system comprising a pacemaker, said system comprising: a. pacing pulse generator means for generating pacing pulses; and b. means for automatically initializing the pulse width of pacing pulses from said pacing pulse means to an optimized value via automatically establishing a Recommended Pulse Width, said means for automatically initializing including pulse width optimizing means; c. said pulse width optimizing means including: i) means for measuring peak pressure values; ii) means for averaging said peak pressure values over a predetermined interval of time; iii) means for determining a rheobase point along a strength duration curve; iv) means for determining a chronaxie point based on said rheobase point; v) means for determining an initialized pulse width parameter according to the following equation: Recommended Pulse Width=Pulse Width of the Chronaxie.

Claim 9

A pacemaker system comprising a pacemaker, said system comprising: a. pacing pulse generator means for generating pacing pulses; and b. means for automatically initializing the pulse width of pacing pulses from said pacing pulse means to an optimized value via automatically establishing a Recommended Pulse Width, said means for automatically initializing including pulse width optimizing means; c. said pulse width optimizing means including: i) means for measuring peak pressure values; ii) means for averaging said peak pressure values over a predetermined interval of time; iii) means for determining a rheobase point along a strength duration curve; iv) means for determining a chronaxie point based on said rheobase point; v) means for determining an initialized pulse width parameter according to the following equation: Recommended Pulse Width=Pulse Width of the Chronaxie.

Claim 10

The pacemaker system as defined in claim 7, further including optimizing means for automatically initializing a pacing pulse amplitude parameter; and wherein said pulse amplitude optimizing means includes means for determining said initialized pulse amplitude parameter according to the following equation: Pulse Amplitude=k×Pulse Amplitude of Chronaxie, where "k" is a programmable coefficient.

Claim 11

The pacemaker system as defined in claim 8, wherein said coefficient "k" is equal to the square root of a recommended safety margin.

Claim 12

A pacemaker system comprising an activity-based, rate-responsive pacemaker, said system comprising: a. pacing pulse generator means for generating pacing pulses; b. rate modulation means coupled to said pacing pulse generator means for modulating said pacing pulses based on sensed activity; and c. means for automatically initializing an activity threshold to be used by said rate modulation means to an optimized value including optimizing means; c. said optimizing means including: i) means for setting the activity threshold to an initial setting; ii) means for periodically counting sensed activity events at rest; and iii) means for automatically selecting one of a plurality of higher settings for said activity threshold, if said counting means indicates a positive activity count.

Claim 13

A pacemaker system comprising an activity-based, rate-responsive pacemaker, said system comprising: a. pacing pulse generator means for generating pacing pulses; b. rate modulation means coupled to said pacing pulse generator means for modulating said pacing pulses based on sensed activity; and c. means for automatically initializing an activity threshold to be used by said rate modulation means to an optimized value including optimizing means; c. said optimizing means including: i) means for setting the activity threshold to an initial setting; ii) means for periodically counting sensed activity events at rest; and iii) means for automatically selecting one of a plurality of higher settings for said activity threshold, if said counting means indicates a positive activity count.

Claim 14

The pacemaker system as defined in claim 10, wherein said optimizing means further includes means for automatically selecting one of a plurality of lower settings for said activity threshold, if said counting means indicates a zero activity count.

Claim 15

A pacemaker system comprising a pacemaker, said system comprising: a. pressure rate-response means for changing pacing rates of said pacemaker in response to sensed pressure signals; b. sensor means for sending pressure rate response gain threshold signals as sensed pacing parameters to said pressure rate-response means; c. processor means for processing the sensed pacing parameters, and for setting optimal values for the pacing parameters; d. said processor means including means for automatically optimizing a pressure rate response gain threshold parameter; and e. said optimizing means including: i) means for counting and measuring valid peak pressure value (dP/dt); ii) means for averaging said peak pressure values over a predetermined interval of time; iii) means for calculating a resting pressure value according to the following equation: ##EQU11## where M is a programmable value in pulses per minute; and iv) means for extrapolating said resting pressure value to calculate the rate response gain setting, as follows: ##EQU12##

Claim 16

A pacemaker system comprising a pacemaker, said system comprising: a. pressure rate-response means for changing pacing rates of said pacemaker in response to sensed pressure signals; b. sensor means for sending pressure rate response gain threshold signals as sensed pacing parameters to said pressure rate-response means; c. processor means for processing the sensed pacing parameters, and for setting optimal values for the pacing parameters; d. said processor means including means for automatically optimizing a pressure rate response gain threshold parameter; and e. said optimizing means including: i) means for counting and measuring valid peak pressure value (dP/dt); ii) means for averaging said peak pressure values over a predetermined interval of time; iii) means for calculating a resting pressure value according to the following equation: ##EQU11## where M is a programmable value in pulses per minute; and iv) means for extrapolating said resting pressure value to calculate the rate response gain setting, as follows: ##EQU12##

Claim 17

The pacemaker system as defined in claim 12 wherein M is equal to 70 pulses per minute.

Claim 18

A pacemaker system comprising a pacemaker, said system comprising: a. pacing pulse generator means for generating pacing pulses, said pacing pulse generator means employing a pacing pulse width parameter and a pacing pulse amplitude parameter; b. rate modulation means coupled to said pacing pulse generator means for modulating said pacing pulses, said rater modulation means employing an activity threshold parameter and a pressure rate response gain threshold parameter; c. at least a sense amplifier employing a sensitivity threshold parameter; and d. processor means, said processor means comprising: i) first optimizing means for optimizing said sensitivity threshold parameter; ii) second optimizing means for automatically initializing said pacing pulse width parameter; iii) third means for automatically initializing said pacing pulse amplitude parameter; iv) fourth optimizing means for automatically initializing said activity threshold parameter; and v) fifth optimizing means for automatically initializing said pressure rate response gain threshold parameter.

Claim 19

A pacemaker system comprising a pacemaker, said system comprising: a. pacing pulse generator means for generating pacing pulses, said pacing pulse generator means employing a pacing pulse width parameter and a pacing pulse amplitude parameter; b. rate modulation means coupled to said pacing pulse generator means for modulating said pacing pulses, said rater modulation means employing an activity threshold parameter and a pressure rate response gain threshold parameter; c. at least a sense amplifier employing a sensitivity threshold parameter; and d. processor means, said processor means comprising: i) first optimizing means for optimizing said sensitivity threshold parameter; ii) second optimizing means for automatically initializing said pacing pulse width parameter; iii) third means for automatically initializing said pacing pulse amplitude parameter; iv) fourth optimizing means for automatically initializing said activity threshold parameter; and v) fifth optimizing means for automatically initializing said pressure rate response gain threshold parameter.