US5725561A — Method and apparatus for variable rate cardiac st…

Claim 1

Independent Claim 257 words

A cardiac pulse delivery and sensing apparatus comprising: a housing adapted to be implanted in an individual said housing containing means for generating and delivering stimulating pulses to an electrical connection outside said housing said electrical connection arranged and disposed for electrical connection to sensing and stimulating pulse delivery lead means and wherein said lead mean are configured and designed to allow for implantation so as to be in close association with said individual's heart so as to provide electrical connection between said heart and said electrical connection, a timing and control processor circuit and a memory circuit within said housing having control of the timing of delivery of said stimulating pulses and for timing said sensed heart signals and for storing values related to such timing in an associated portion of said memory circuit and wherein said processor circuit comprises as least two processors; a rate smoothing determining processor for determining whether rate smoothing criteria are met in sensed signals from said heart when a rapid rate drop is detected and; a rate support determining processor for determining from said values related to such timing when to maintain a support rate, said maintenance of support rate processor having two modes, a tracking mode which follows an intrinsic atrial rate and a decay mode which allows the support rate to fall in a controlled manner and wherein said timing and control processor circuit also comprises circuit means for adjusting the timing of said stimulating pulses in response to said rate smoothing processor and rate support processor's determining.

Claim 2

Dependent Claim 257 words

A cardiac pulse delivery and sensing apparatus comprising: a housing adapted to be implanted in an individual said housing containing means for generating and delivering stimulating pulses to an electrical connection outside said housing said electrical connection arranged and disposed for electrical connection to sensing and stimulating pulse delivery lead means and wherein said lead mean are configured and designed to allow for implantation so as to be in close association with said individual's heart so as to provide electrical connection between said heart and said electrical connection, a timing and control processor circuit and a memory circuit within said housing having control of the timing of delivery of said stimulating pulses and for timing said sensed heart signals and for storing values related to such timing in an associated portion of said memory circuit and wherein said processor circuit comprises as least two processors; a rate smoothing determining processor for determining whether rate smoothing criteria are met in sensed signals from said heart when a rapid rate drop is detected and; a rate support determining processor for determining from said values related to such timing when to maintain a support rate, said maintenance of support rate processor having two modes, a tracking mode which follows an intrinsic atrial rate and a decay mode which allows the support rate to fall in a controlled manner and wherein said timing and control processor circuit also comprises circuit means for adjusting the timing of said stimulating pulses in response to said rate smoothing processor and rate support processor's determining.

Claim 3

Dependent Claim 212 words

An apparatus as set forth in claim 1 wherein said rate smoothing determining processor bases its determination on a current Averaged Atrial Interval (AAI) value stored and updated in said memory circuit in which value is the measure of a previous AAI summed with a value for an increment of time or decremented by a value for a decrement of time such that: a) said previous AAI is incremented by a positive increment interval when the time between the last pair of atrial sensed events or the time between a leading sensed atrial event and a paced atrial event or the time between the last two atrial paced events is less than the value of the previous AAI, but b) said previous AAI is decremented by a negative increment interval when the time between the last pair of atrial sensed events or the time between a leading sensed atrial event and a paced atrial event or the time between the last two atrial paced events is greater than the value of the previous AAI; such that if the current AAI is less than the value of the previous AAI minus a predetermined Maximum Rate Drop interval value, then an indicator value in a memory circuit in favor of rate smoothing is "set".

Claim 4

Dependent Claim 90 words

An apparatus as set forth in claim 2 wherein when said indicator "Count N" is set in favor of rate smoothing and a next indicator value in said memory circuit will be either: "set" depending on if the current AAI is less than the value of the previous AAI minus said predetermined Maximum Rate Drop interval value; and "not-set" if not and wherein a set of all previously set or not-set indicator values is used by said rate smoothing determining circuit to determine whether or not to initiate rate smoothing.

Claim 5

Dependent Claim 97 words

An apparatus as set forth in claim 3 wherein the set of indicators available to be put into either said set or not-set condition is equal to a number P, said number P being a variable representing a number of memory circuit elements in said memory circuit that can be used for storing said set or not set variables and an index "CountP" is set equal to the variable from 1 to P that is being considered, and when the value of the index CountP=P, the next variable to be set or reset is indexed by CountP=1.

Claim 6

Dependent Claim 110 words

An apparatus as set forth in claim 2 wherein when said indicator is set a next indicator will be either: "set" depending on if the current AAI is less than the value of the previous AAI minus said predetermined Maximum Rate Drop interval value; and "not-set" if not and wherein the total of all previously set indicator values is determined and said total is compared by said rate smoothing determining circuit to a predetermined number N stored in said memory circuit and if said total is determined to be greater or equal to N, then said rate smoothing determining circuit signals said timing and control circuit to initiate rate smoothing.

Claim 7

Dependent Claim 30 words

An apparatus as set forth in claim 5 wherein the number N is predetermined by a user and stored by that user into said memory circuit for storing N's value.

Claim 8

Dependent Claim 36 words

An apparatus as set forth in claim 2 wherein the rate smoothing is accomplished by said rate smoothing processor accomplishing the summing of the current AAI with a small additional increment to reach the next AAI.

Claim 9

Dependent Claim 49 words

An apparatus as set forth in claim 7 wherein said small additional increment size is a storable value set by a user and stored by that user into said memory circuit for storing said additional increment's size value by use of a device that can communicate with said apparatus.

Claim 10

Dependent Claim 59 words

Apparatus as set forth in claim 1 wherein said timing and control processor circuit can be controlled by reference to a value by either said rate smoothing determining processor or by said rate support determining processor or by both processors depending on the value which is set by a user and stored by that user into said memory circuit.

Claim 11

Dependent Claim 30 words

Apparatus as set forth in claim 1 wherein said timing and control processor circuit is controlled by both said rate smoothing determining processor and by said rate support determining processor.

Claim 12

Dependent Claim 30 words

Apparatus as set forth in claim 9 wherein said rate support determining processor supports PRS and wherein said rate support processor is only activated upon achievement of a predetermined criterion.

Claim 13

Dependent Claim 46 words

Apparatus as set forth in claim 9 wherein said rate support determining processor supports PRS and wherein when said rate support processor is activated in accord with preset criteria, said activation causes an indication of said meeting of such criterion to be reported to the user.

Claim 14

Dependent Claim 209 words

A cardiac pulse delivery and sensing apparatus comprising: a housing adapted to be implanted in an individual said housing containing means for generating and delivering stimulating pulses to an electrical connection outside said housing said electrical connection arranged and disposed for electrical connection to sensing and pulse delivery leads connected thereto and wherein said leads are configured and designed to allow for implantation so as to be in close association with said individual's heart so as to provide electrical connection between said heart and said electrical connection, a timing and control processor circuit and a memory circuit within said housing having control of the timing of delivery of said stimulating pulses and for timing said sensed heart signals and for storing values related to such timing in an associated portion of said memory circuit wherein said processor circuit comprises; a rate smoothing determining processor for determining whether rate smoothing criteria are met in sensed signals from said heart if a rapid rate drop is detected; and wherein said processor circuit also comprises circuit means for adjusting the timing of said stimulating pulses in response to said determination so as to allow said drop to occur in a smoothed manner without first raising a pacing rate to a predetermined rate.

Claim 15

Dependent Claim 209 words

A cardiac pulse delivery and sensing apparatus comprising: a housing adapted to be implanted in an individual said housing containing means for generating and delivering stimulating pulses to an electrical connection outside said housing said electrical connection arranged and disposed for electrical connection to sensing and pulse delivery leads connected thereto and wherein said leads are configured and designed to allow for implantation so as to be in close association with said individual's heart so as to provide electrical connection between said heart and said electrical connection, a timing and control processor circuit and a memory circuit within said housing having control of the timing of delivery of said stimulating pulses and for timing said sensed heart signals and for storing values related to such timing in an associated portion of said memory circuit wherein said processor circuit comprises; a rate smoothing determining processor for determining whether rate smoothing criteria are met in sensed signals from said heart if a rapid rate drop is detected; and wherein said processor circuit also comprises circuit means for adjusting the timing of said stimulating pulses in response to said determination so as to allow said drop to occur in a smoothed manner without first raising a pacing rate to a predetermined rate.

Claim 16

Dependent Claim 218 words

A cardiac pulse delivery and sensing apparatus comprising: a housing adapted to be implanted in an individual said housing containing means for generating and delivering stimulating pulses to an electrical connection outside said housing said electrical connection arranged and disposed for electrical connection to sensing and pulse delivery leads connected thereto and wherein said lead are configured and designed to allow for implantation so as to be in close association with said individual's heart so as to provide electrical connection between said heart and said electrical connection, a timing and control processor circuit and a memory circuit means within said housing having control of the timing of delivery of said stimulating pulses, for timing said sensed heart signals and for storing values related to such timing in an associated portion of said memory circuit means and wherein said processor circuit comprises; a rate support determining processor for determining from said stored values when to maintain a support rate so as to prevent rapid rate drops; and wherein said processor circuit also comprises circuit means for adjusting the timing of said stimulating pulses in response to said determination, said support rate processor having two modes, a tracking mode which follows an intrinsic atrial rate and a decay mode which allows the support rate to fall in a controlled manner.

Claim 17

Dependent Claim 218 words

A cardiac pulse delivery and sensing apparatus comprising: a housing adapted to be implanted in an individual said housing containing means for generating and delivering stimulating pulses to an electrical connection outside said housing said electrical connection arranged and disposed for electrical connection to sensing and pulse delivery leads connected thereto and wherein said lead are configured and designed to allow for implantation so as to be in close association with said individual's heart so as to provide electrical connection between said heart and said electrical connection, a timing and control processor circuit and a memory circuit means within said housing having control of the timing of delivery of said stimulating pulses, for timing said sensed heart signals and for storing values related to such timing in an associated portion of said memory circuit means and wherein said processor circuit comprises; a rate support determining processor for determining from said stored values when to maintain a support rate so as to prevent rapid rate drops; and wherein said processor circuit also comprises circuit means for adjusting the timing of said stimulating pulses in response to said determination, said support rate processor having two modes, a tracking mode which follows an intrinsic atrial rate and a decay mode which allows the support rate to fall in a controlled manner.

Claim 18

Dependent Claim 74 words

Apparatus as set forth in claim 14, said timing and control circuit further comprising a sensor and a rate drop determination circuit, wherein the rate support determining processor is only triggered by said sensor and rate drop determination circuit and wherein said rate drop determination circuit determines based on sensed depolarizations that an occurrence of a drop in intrinsic rate from a predetermined maximum to a predetermined minimum within a given period has occurred.

Claim 19

Dependent Claim 66 words

Apparatus as set forth in claim 14, said timing and control circuit further comprising a sensor and a rate drop determination circuit, wherein the rate support determining processor is only triggered by said sensor and rate drop determination circuit that determines based on sensed depolarizations that an occurrence of a drop in intrinsic rate by a predetermined absolute value over a given time period has occurred.

Claim 20

Dependent Claim 63 words

Apparatus as set forth in claim 14, said timing and control circuit further comprising a sensor and a rate drop determination circuit, wherein the rate support determining processor is triggered by triggered by said sensor and rate drop determination circuit that determines based on sensed depolarizations that an occurrence of a predefined drop in the intrinsic rate over a given period has occurred.

Claim 21

Dependent Claim 93 words

Apparatus as set forth in claim 14 wherein said timing and control circuit retains timing values of escape intervals, including a present and a previous escape interval, and wherein when the rate support determining processor is on, said timing and control circuit functions by increasing an escape interval to slow pacing from one paced beat to the next, but does not function to slow pacing during "decay beats" while in said decay mode, the number of said decay beats being determined by whether an intrinsic event is found within said previous escape interval.

Claim 22

Independent Claim 152 words

A method for timing and controlling the delivery of pacing pulses to a heart comprising one step from the following set of steps, a, b, and c: a) 1) monitoring and detecting occurrences of rapid rate drop 2) when a rapid heart rate is detected, enabling a processor to apply smoothing criteria to the timing of delivery of subsequent pacing pulses, b) 1) monitoring and detecting occurrences of wide variation in heart rate, 2) enabling a processor to apply rate support criteria to subsequent pacing pulses following the detection of an occurrence of wide rate variation, and c) 1) monitoring and detecting occurrences of rapid rate drop and wide variation in intrinsic heart rate 2) when a rapid heart rate drop or occurrence of wide rate variation is detected, enabling a processor to apply a combination of rate support and rate smoothing criteria to the timing and delivery of subsequent pacing pulses.

Claim 23

Independent Claim 152 words

A method for timing and controlling the delivery of pacing pulses to a heart comprising one step from the following set of steps, a, b, and c: a) 1) monitoring and detecting occurrences of rapid rate drop 2) when a rapid heart rate is detected, enabling a processor to apply smoothing criteria to the timing of delivery of subsequent pacing pulses, b) 1) monitoring and detecting occurrences of wide variation in heart rate, 2) enabling a processor to apply rate support criteria to subsequent pacing pulses following the detection of an occurrence of wide rate variation, and c) 1) monitoring and detecting occurrences of rapid rate drop and wide variation in intrinsic heart rate 2) when a rapid heart rate drop or occurrence of wide rate variation is detected, enabling a processor to apply a combination of rate support and rate smoothing criteria to the timing and delivery of subsequent pacing pulses.

Claim 24

Independent Claim 71 words

A method for timing and controlling the delivery of pacing pulses to a heart comprising: monitoring and detecting occurrences of rapid rate drop when an intrinsic rapid heart rate drop is detected, enabling a processor to apply smoothing criteria to the timing of delivery of subsequent pacing pulses such that an intrinsic rapid rate drop is not allowed to occur but instead a smoothed rate drop is supported by said timing.

Claim 25

Independent Claim 71 words

A method for timing and controlling the delivery of pacing pulses to a heart comprising: monitoring and detecting occurrences of rapid rate drop when an intrinsic rapid heart rate drop is detected, enabling a processor to apply smoothing criteria to the timing of delivery of subsequent pacing pulses such that an intrinsic rapid rate drop is not allowed to occur but instead a smoothed rate drop is supported by said timing.

Claim 26

Independent Claim 114 words

A method for timing and controlling the delivery of pacing pulses to a heart comprising: monitoring and detecting occurrences of wide variation in heart rate when an occurrence of wide variation in heart rate is detected, enabling a processor to apply rate support criteria to the timing of delivery of subsequent pacing pulses such that the paced patient's intrinsic rate is not allowed to fall by adjusting the timing of pacing pulse delivery downward no faster than extinction of a timed interval adjusted by said processor to reflect the amount of rate support needed so said interval is directly proportional in size to the amount of support determined by said processor to be needed.

Claim 27

Independent Claim 114 words

A method for timing and controlling the delivery of pacing pulses to a heart comprising: monitoring and detecting occurrences of wide variation in heart rate when an occurrence of wide variation in heart rate is detected, enabling a processor to apply rate support criteria to the timing of delivery of subsequent pacing pulses such that the paced patient's intrinsic rate is not allowed to fall by adjusting the timing of pacing pulse delivery downward no faster than extinction of a timed interval adjusted by said processor to reflect the amount of rate support needed so said interval is directly proportional in size to the amount of support determined by said processor to be needed.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2001-03-09	2001-09-08	2002-03-10	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2005-03-09	2005-09-08	2006-03-10	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2009-03-09	2009-09-08	2010-03-10	$7700.00	Window Closed / Lapsed

Method and apparatus for variable rate cardiac stimulation

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag