EP0229886A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Exercise-responsive rate-adaptive cardiac pacemaker
Assignee: Individual
•
Filing: 1986-10-16
•
Granted: —
•
Expires: 2006-10-16
Abstract
Abstract A temperature driven rate responsive cardiac pacemaker adapted to distinguish between physiologically determined changes of the patient's blood temperature under conditions of exercise and non-exercise, and to adaptively vary the rate at which stimuli are generated accordingly, is also capable of recognizing the blood temperature dip which is characteristic of the commencement of exercise. In response to such a temperature dip, the pacemaker initiates a rapid and physiologically beneficial increase in the stimulation rate. To assure the proper selective initiation of a rate increase, the pacemaker discriminates between a blood temperature drop indicative of the onset of exercise and those temperature drops which occur for other reasons, such as upon cessation of exercise or as normal phasic variations, including respiration and circadian fluctuations.
Inventors
- 👤 Eckhard Dr. Alt
- 👤 Richard Dr. Calfee
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 17:19
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/36; A61N1/362; A61N1/365; A61N1/36514; A61N1/3655
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
343 words
A cardiac pacemaker including a control device for automatic adaptation of the stimulation rate to the metabolic state of the patient, with a temperature sensor for detecting the temperature of the central venous blood in the heart, the sensor situated on a transvenous lead in proximity to the stimulation electrode such that the sensor may be introduced with the stimulation electrode into the atrium or the ventricle of the heart, and a circuit connected to the sensor which controls the stimulation rate dependent on the blood temperature detected by the sensor, wherein said circuit continually evaluates from the detected blood temperature the temporal change of the blood temperature at any given time, and if the temporal change of the blood temperature does not exceed a certain minimum, said circuit controls the stimulation rate in accordance with a reference characteristic function curve which corresponds to the body in rest state, but, if the temporal change of the blood temperature exceeds this minimum, said circuit controls the stimulation rate in accordance with exercise characteristic function curves which correspond to body exercise conditions, wherein each exercise curve begins at a different working point on the reference curve and, at one and the same temperature, each exercise curve has a higher stimulation rate than the reference curve and all exercise curves have a higher slope than the reference curve, characterized in that said circuit (11), if the pacemaker (1) is controlled in accordance with the reference curve (K2) and the current stimulation rate (HF) does not exceed a certain upper value, will increase the stimulation rate (HF) according to an initial characteristic curve (K-i) for a certain time period following the exercise-dependent initial decrease of the detected blood temperature (T), if the magnitude of the decrease exceeds a certain threshold value (ΔT) within a certain time span, and will switch the control of the stimulation rate (HF) from the initial characteristic curve (K-i) to control according to an exercise curve (K1), if the temporal change of the increase of the blood temperature exceeds a given minimum value.
Claim 2
Dependent Claim
343 words
A cardiac pacemaker including a control device for automatic adaptation of the stimulation rate to the metabolic state of the patient, with a temperature sensor for detecting the temperature of the central venous blood in the heart, the sensor situated on a transvenous lead in proximity to the stimulation electrode such that the sensor may be introduced with the stimulation electrode into the atrium or the ventricle of the heart, and a circuit connected to the sensor which controls the stimulation rate dependent on the blood temperature detected by the sensor, wherein said circuit continually evaluates from the detected blood temperature the temporal change of the blood temperature at any given time, and if the temporal change of the blood temperature does not exceed a certain minimum, said circuit controls the stimulation rate in accordance with a reference characteristic function curve which corresponds to the body in rest state, but, if the temporal change of the blood temperature exceeds this minimum, said circuit controls the stimulation rate in accordance with exercise characteristic function curves which correspond to body exercise conditions, wherein each exercise curve begins at a different working point on the reference curve and, at one and the same temperature, each exercise curve has a higher stimulation rate than the reference curve and all exercise curves have a higher slope than the reference curve, characterized in that said circuit (11), if the pacemaker (1) is controlled in accordance with the reference curve (K2) and the current stimulation rate (HF) does not exceed a certain upper value, will increase the stimulation rate (HF) according to an initial characteristic curve (K-i) for a certain time period following the exercise-dependent initial decrease of the detected blood temperature (T), if the magnitude of the decrease exceeds a certain threshold value (ΔT) within a certain time span, and will switch the control of the stimulation rate (HF) from the initial characteristic curve (K-i) to control according to an exercise curve (K1), if the temporal change of the increase of the blood temperature exceeds a given minimum value.
Claim 3
Dependent Claim
65 words
The cardiac pacemaker according to Claim 1, characterized in that the initial characteristic curve (K-i) describes the course of stimulation rate (HF) with time with an initial rate increase which is held for a certain time period (line d) and a subsequent delayed return (line e) of the rate in the direction of the stimulation rate associated with the temperature on the reference curve (K2).
Claim 4
Dependent Claim
47 words
The cardiac pacemaker according to Claim 1, characterized in that the transition to control of the stimulation rate (HF) according to an exercise curve (K1) occurs at that moment when the rate associated with that exercise curve equals the rate given by the initial characteristic curve (K-i).
Claim 5
Dependent Claim
75 words
The cardiac pacemaker according to Claim 1, characterized in that the transition to control of the stimulation rate (HF) according to an exercise curve (K1) occurs at that moment when the predetermined criteria for exercise according to that exercise curve are fulfilled, and also in that said circuit (11) controls the stimulation rate (HF) according to this exercise curve beginning with a rate corresponding to that of the initial characteristic curve (K-i) at that moment.
Claim 6
Dependent Claim
54 words
A rate-responsive cardiac pacemaker, comprising means for detecting the onset of exercise by the patient by recognizing the characteristic drop in the patient's central venous blood temperature often associated with the onset of exercise, and means for adjusting the stimulation rate of the pacemaker in response to that detection of the onset of exercise.
Claim 7
Dependent Claim
54 words
A rate-responsive cardiac pacemaker, comprising means for detecting the onset of exercise by the patient by recognizing the characteristic drop in the patient's central venous blood temperature often associated with the onset of exercise, and means for adjusting the stimulation rate of the pacemaker in response to that detection of the onset of exercise.
Claim 8
Dependent Claim
144 words
The pacemaker of Claim 5, in which said detecting means recognizes said characteristic drop by applying at least some of the criteria that the temperature drop occur at a point in time at which control of stimulation rate of the pacemaker be according to an algorithm relating stimulation rate to blood temperature characteristic of a condition of physical inactivity of the patient, that the temperature drop occur at a point in time at which patient's current heart rate does not exceed a predetermined threshold rate that may be indicative of recently completed exercise, that the magnitude of the temperature drop exceed a predetermined threshold value, and that the time rate of change of the temperature drop be within a predetermined range of slopes and extremes of which may be indicative of recently completed exercise or of a change associated with the patient's circadian rhythm.
Claim 9
Dependent Claim
61 words
The pacemaker of Claim 6, in which said predetermined threshold heart rate is equal to or greater than about 85 beats per minute, said predetermined threshold value of the temperature drop is in the range of approximately 0.12 to 0.25 degree C, and said predetermined range of slopes of the temperature drop is approximately 0.12 to 0.2 degree C per minute.
Claim 10
Dependent Claim
46 words
The pacemaker of Claim 5, in which said adjusting means rapidly increases the stimulation rate in response to said detection, and maintains the stimulation rate at the increased level for a predetermined period of time at least equal to the duration of the recognized temperature drop.
Claim 11
Dependent Claim
42 words
The pacemaker of Claim 8, in which said adjusting means controls the stimulation rate after said predetermined period of time according to an algorithm relating stimulation rate to blood temperature characteristic of a condition of exercise, for the period of continuing exercise.
Claim 12
Dependent Claim
75 words
A stimulus generator for a temperature driven rate responsive cardiac pacemaker, comprising means for detecting the onset of exercise by the patient by recognizing the characteristic drop in central venous blood temperature often associated with onset of exercise, means for distinguishing the exercise onset-characteristic drop in blood temperature from the behavior of the blood temperature at other times, and means responsive to said exercise onset detection for adjusting the stimulation rate of the generator accordingly.
Claim 13
Dependent Claim
75 words
A stimulus generator for a temperature driven rate responsive cardiac pacemaker, comprising means for detecting the onset of exercise by the patient by recognizing the characteristic drop in central venous blood temperature often associated with onset of exercise, means for distinguishing the exercise onset-characteristic drop in blood temperature from the behavior of the blood temperature at other times, and means responsive to said exercise onset detection for adjusting the stimulation rate of the generator accordingly.
Claim 14
Dependent Claim
56 words
The stimulus generator according to Claim 10, in which said detecting means recognizes said exercise onset-characteristic temperature drop by applying at least one of the criteria that the magnitude of the temperature drop must exceed a predetermined minimum value, and that the time rate of change of the temperature drop must exceed a predetermined minimum slope.
Claim 15
Dependent Claim
110 words
The stimulus generator according to Claim 11, in which said distinguishing means assists said detecting means in recognizing said exercise onset-characteristic temperature drop and discriminates from the behavior of the blood temperature at other times by applying at least one of the criteria that the temperature drop must occur at a point in time at which the stimulation rate of the generator is controlled according to an algorithm relating stimulation rate to blood temperature characteristic of a condition of physical inactivity of the patient, and that at said point in time the patient's heart rate must not exceed a predetermined threshold rate tending to indicate a recent condition of exercise.
Claim 16
Dependent Claim
33 words
The stimulus generator according to Claim 10, in which said adjusting means increases the stimulation rate to a predetermined rate level in response to recognition and distinguishment of the exercise onset-characteristic temperature drop.
Claim 17
Dependent Claim
36 words
The stimulus generator according to Claim 13, in which said adjusting means maintains the stimulation rate at said predetermined rate level for a period of time at least equal to the period of the temperature drop.
Claim 18
Dependent Claim
43 words
The stimulus generator according to Claim 14, in which said adjusting means controls the stimulation rate after said period of time according to an algorithm relating stimulation rate to blood temperature characteristic of a condition of exercise, for the duration of the exercise.
Claim 19
Dependent Claim
105 words
The stimulus generator according to Claim 10, in which said adjusting means adjusts the stimulation rate to an increased rate level for a predetermined period of time in response to said exercise onset detection, and at the conclusion of said period of time said adjusting means adjusts the stimulation rate to revert to the rate existing immediately prior to said detection, unless continuing exercise of the patient is detected, and, in response to detection of continuing exercise, said adjusting means interrupts said rate reversion and adjusts the stimulation rate according to an algorithm relating stimulation rate to blood temperature characteristic of a condition of exercise.
Claim 20
Dependent Claim
104 words
In an implantable cardiac pacemaker for adaptively varying the heart rate of a patient based on the level of the patient's central venous blood temperature, the improvement comprising means for detecting a drop of predetermined extent and duration in the blood temperature from a time when the patient is in a resting state, as indicative of the commencement of physical activity by the patient, and means responsive to said detection for rapidly increasing the stimulation rate of the pacemaker in an amount and for a time commensurate with physiological response to the commencement of exercise in a healthy person with a normally functioning heart.
Claim 21
Dependent Claim
104 words
In an implantable cardiac pacemaker for adaptively varying the heart rate of a patient based on the level of the patient's central venous blood temperature, the improvement comprising means for detecting a drop of predetermined extent and duration in the blood temperature from a time when the patient is in a resting state, as indicative of the commencement of physical activity by the patient, and means responsive to said detection for rapidly increasing the stimulation rate of the pacemaker in an amount and for a time commensurate with physiological response to the commencement of exercise in a healthy person with a normally functioning heart.
Claim 22
Dependent Claim
81 words
An exercise responsive cardiac pacemaker, comprising means for controllably varying the stimulation rate of the pacemaker according to whether the patient is at rest or undergoing exercise, based on the instantaneous level of the patient's blood temperature, and means responsive to a relatively rapid drop in the patient's blood temperature commencing from an apparent state of rest of the patient, as indicating commencement of exercise by the patient, and for thereupon increasing the stimulation rate to a level consistent with exercise.
Claim 23
Dependent Claim
81 words
An exercise responsive cardiac pacemaker, comprising means for controllably varying the stimulation rate of the pacemaker according to whether the patient is at rest or undergoing exercise, based on the instantaneous level of the patient's blood temperature, and means responsive to a relatively rapid drop in the patient's blood temperature commencing from an apparent state of rest of the patient, as indicating commencement of exercise by the patient, and for thereupon increasing the stimulation rate to a level consistent with exercise.
Claim 24
Independent Claim
105 words
A method for adaptively regulating an exercise responsive cardiac pacemaker in which the stimulation rate is based on the central venous blood temperature of the patient according to whether the patient is resting or undergoing exercise, said method comprising detecting a drop in the blood temperature level exceeding a predetermined amount and a predetermined time rate of change, at a time when the patient is in an apparent state of rest with a heart rate not exceeding a predetermined threshold rate, recognizing such detected temperature drop as denoting the onset of exercise by the patient, and significantly increasing the stimulation rate coincident with such detection.
Claim 25
Independent Claim
105 words
A method for adaptively regulating an exercise responsive cardiac pacemaker in which the stimulation rate is based on the central venous blood temperature of the patient according to whether the patient is resting or undergoing exercise, said method comprising detecting a drop in the blood temperature level exceeding a predetermined amount and a predetermined time rate of change, at a time when the patient is in an apparent state of rest with a heart rate not exceeding a predetermined threshold rate, recognizing such detected temperature drop as denoting the onset of exercise by the patient, and significantly increasing the stimulation rate coincident with such detection.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.