EP0616819A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Rate-responsive pacemaker
Assignee: Individual
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Filing: 1989-02-16
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Granted: —
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Expires: 2009-02-16
Abstract
Abstract A pacemaker has means for producing first and second signals one of which changes rapidly in response to changes in exercise level but may inaccurately represent the appropriate pacing rate. Such signal may be derived from a vibration sensor. The second signal accurately represents the required pacing rate but changes slowly in response to exercise level and may represent any of a number of different physiological variables, such as respiratory rate. The signals may be derived from the same or separate sensors. A control circuit provides a pacing rate appropriate to resting conditions if the first signal has a value less than a threshold regardless of the value of the second signal. The pacing rate is elevated to a predetermined level, such as 95 beats/min, if the first signal exceeds the threshold but the second signal has a value indicative of a pacing rate less than the predetermined level. The pacing rate is further elevated to substantially equal that indicated by the value of the second signal when the first signal exceeds the threshold and the second signal indicates a rate higher than the predetermined rate.
Inventors
- 👤 Stuart Charles Webb
- 👤 Leland Milton Lewis
- 👤 Jayne Alison Morris-Thurgood
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 15:29
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/36; A61N1/362; A61N1/365; A61N1/36585
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
44 words
A sensing arrangement for a pacemaker, comprising a single sensor, and a signal processing means for processing signals from said sensor to produce a first output signal representative of a first biological variable and a second output signal representative of a second biological variable.
Claim 2
Dependent Claim
44 words
A sensing arrangement for a pacemaker, comprising a single sensor, and a signal processing means for processing signals from said sensor to produce a first output signal representative of a first biological variable and a second output signal representative of a second biological variable.
Claim 3
Dependent Claim
23 words
An arrangement according to claim 1, wherein said first biological variable is bodily vibration and said second biological variable is a physiological variable.
Claim 4
Dependent Claim
13 words
An arrangement according to claim 2, wherein said sensor is a vibration sensor.
Claim 5
Dependent Claim
13 words
An arrangement according to claim 3, wherein said processing means comprises filtering means.
Claim 6
Dependent Claim
41 words
An arrangement according to claim 4, wherein said filtering means is operable to provide said first signal by passing a frequency band in the region of 10Hz and to provide said second signal by passing frequencies of less than about 0.5Hz.
Claim 7
Dependent Claim
17 words
An arrangement according to any of claims 3 to 5, wherein said physiological variable is respiratory rate.
Claim 8
Dependent Claim
186 words
A pacemaker comprising: sensing means for providing a first signal which changes relatively rapidly in response to changes in a patient's exercise level but may inaccurately represent the pacing rate appropriate to said exercise level and a second signal which changes relatively slowly in response to changes in exercise level but, after having changed, relatively accurately represents the required pacing rate; and control means for controlling pacing rate in response to said sensing means, said control means being operative: (A) to provide a relatively low pacing rate when said first signal has a value less than a threshold; (B) to provide a predetermined pacing rate higher than said relatively low rate when the first signal exceeds said threshold and the second signal has a value indicative of a pacing rate less than said predetermined rate; and (C) to provide a pacing rate substantially equal to that indicated by the value of said second signal when the first signal exceeds said threshold and the second signal indicates a rate higher than said predetermined rate, regardless of the amount by which said first signal may exceed said threshold.
Claim 9
Dependent Claim
186 words
A pacemaker comprising: sensing means for providing a first signal which changes relatively rapidly in response to changes in a patient's exercise level but may inaccurately represent the pacing rate appropriate to said exercise level and a second signal which changes relatively slowly in response to changes in exercise level but, after having changed, relatively accurately represents the required pacing rate; and control means for controlling pacing rate in response to said sensing means, said control means being operative: (A) to provide a relatively low pacing rate when said first signal has a value less than a threshold; (B) to provide a predetermined pacing rate higher than said relatively low rate when the first signal exceeds said threshold and the second signal has a value indicative of a pacing rate less than said predetermined rate; and (C) to provide a pacing rate substantially equal to that indicated by the value of said second signal when the first signal exceeds said threshold and the second signal indicates a rate higher than said predetermined rate, regardless of the amount by which said first signal may exceed said threshold.
Claim 10
Dependent Claim
18 words
A pacemaker according to claim 7, wherein said control means is operable to change the pacing rate linearly.
Claim 11
Dependent Claim
18 words
A pacemaker according to claim 7, wherein said control means is operable to change the pacing rate non-linearly.
Claim 12
Dependent Claim
18 words
A pacemaker according to claim 7, wherein the control means is operable to change the pacing rate stepwise.
Claim 13
Dependent Claim
25 words
A pacemaker according to any preceding claim, comprising a first sensor for providing said first signal and a second sensor for providing said second signal.
Claim 14
Dependent Claim
27 words
A pacemaker according to claim 11, wherein said first sensor is operable to sense bodily vibrations and said second sensor is operable to sense a physiological variable.
Claim 15
Dependent Claim
32 words
A pacemaker according to claim 11, wherein said physiological variable is evoked QT interval, respiratory rate, minute ventilation, mixed venous temperature, venous oxygen saturation, or rate of change of right ventricular pressure.
Claim 16
Dependent Claim
32 words
A pacemaker according to any of claims 7 to 11, having a single sensor and processing means for processing signals from said single sensor to produce said first and second signals respectively.
Claim 17
Dependent Claim
21 words
A pacemaker according to claim 14, wherein said single sensor is a vibration sensor and said processing means comprises filtering means.
Claim 18
Dependent Claim
40 words
A pacemaker according to claim 15, wherein said filtering means is operable to provide said first signal by passing a frequency band in the region of 10Hz and to provide said second signal by passing frequencies less than about 0.5Hz.
Claim 19
Dependent Claim
13 words
A pacemaker according to claim 16, wherein said second signal represents respiratory rate.
Claim 20
Dependent Claim
29 words
A pacemaker according to any of claims 12, 13 and 15 to 17, wherein said threshold is defined as both a magnitude and a frequency of said first signal.
Claim 21
Dependent Claim
15 words
A pacemaker according to any preceding claim, wherein said predetermined rate is approximately 95 beats/min.
Claim 22
Dependent Claim
37 words
A pacemaker according to any preceding claim, wherein said control means is operable to define predetermined minimum and maximum values for said pacing rate and to maintain the pacing rate within said values regardless of said signals.
Claim 23
Dependent Claim
204 words
A pacemaker comprising: sensing means for providing a first signal which changes relatively rapidly in response to changes in a patient's exercise level but may inaccurately represent the pacing rate appropriate to said exercise level and a second signal which changes relatively slowly in response to changes in exercise level but, after having changed, relatively accurately represents the required pacing rate; and control means for controlling pacing rate in response to said sensing means, said control means being operative: (A) to provide a relatively low pacing rate unless said first signal includes frequency components having an amplitude above a predetermined amplitude and a frequency above a threshold frequency of at least 7 cycles per second; (B) to provide a predetermined pacing rate higher than said relatively low rate when said first signal includes frequency components having an amplitude above said predetermined amplitude and a frequency above said threshold frequency and the second signal has a value indicative of a pacing rate less than said predetermined rate; and (C) to provide a pacing rate substantially equal to that indicated by the value of said second signal when the first signal exceeds said threshold and the second signal indicates a rate higher than said predetermined rate.
Claim 24
Dependent Claim
204 words
A pacemaker comprising: sensing means for providing a first signal which changes relatively rapidly in response to changes in a patient's exercise level but may inaccurately represent the pacing rate appropriate to said exercise level and a second signal which changes relatively slowly in response to changes in exercise level but, after having changed, relatively accurately represents the required pacing rate; and control means for controlling pacing rate in response to said sensing means, said control means being operative: (A) to provide a relatively low pacing rate unless said first signal includes frequency components having an amplitude above a predetermined amplitude and a frequency above a threshold frequency of at least 7 cycles per second; (B) to provide a predetermined pacing rate higher than said relatively low rate when said first signal includes frequency components having an amplitude above said predetermined amplitude and a frequency above said threshold frequency and the second signal has a value indicative of a pacing rate less than said predetermined rate; and (C) to provide a pacing rate substantially equal to that indicated by the value of said second signal when the first signal exceeds said threshold and the second signal indicates a rate higher than said predetermined rate.
Claim 25
Dependent Claim
15 words
A pacemaker according to claim 21, wherein said threshold frequency is 10 cycles per second.
Claim 26
Dependent Claim
186 words
A pacemaker comprising: sensing means for providing a first signal which changes relatively rapidly in response to changes in a patient's exercise level but may inaccurately represent the pacing rate appropriate to said exercise level and a second signal which changes relatively slowly in response to changes in exercise level but, after having changed, relatively accurately represents the required pacing rate; and control means for controlling pacing rate in response to said sensing means, said control means being operative: (A) to define for said first signal a single substantially constant threshold value; (B) to provide a relatively low pacing rate when said has a value less than said threshold value; (C) to provide a predetermined pacing rate higher than said relatively low rate when the first signal exceeds said threshold value and the second signal has a value indicative of a pacing rate less than said predetermined rate; and (D) to provide a pacing rate substantially equal to that indicated by the value of said second signal when the first signal exceeds said threshold and the second signal indicates a rate higher than said predetermined rate.
Claim 27
Dependent Claim
186 words
A pacemaker comprising: sensing means for providing a first signal which changes relatively rapidly in response to changes in a patient's exercise level but may inaccurately represent the pacing rate appropriate to said exercise level and a second signal which changes relatively slowly in response to changes in exercise level but, after having changed, relatively accurately represents the required pacing rate; and control means for controlling pacing rate in response to said sensing means, said control means being operative: (A) to define for said first signal a single substantially constant threshold value; (B) to provide a relatively low pacing rate when said has a value less than said threshold value; (C) to provide a predetermined pacing rate higher than said relatively low rate when the first signal exceeds said threshold value and the second signal has a value indicative of a pacing rate less than said predetermined rate; and (D) to provide a pacing rate substantially equal to that indicated by the value of said second signal when the first signal exceeds said threshold and the second signal indicates a rate higher than said predetermined rate.
Claim 28
Dependent Claim
193 words
A pacemaker comprising: sensing means for providing a first signal which changes relatively rapidly in response to changes in a patient's exercise level but may inaccurately represent the pacing rate appropriate to said exercise level and a second signal which changes relatively slowly in response to changes in exercise level but, after having changed, relatively accurately represents the required pacing rate; and control means for controlling pacing rate in response to said sensing means, said control means being operative: (A) to provide a relatively low pacing rate when said first signal has a value less than a threshold; (B) to provide a predetermined pacing rate higher than said relatively low rate when the first signal exceeds said threshold and the second signal has a value indicative of a pacing rate less than said predetermined rate; (C) to provide a pacing rate substantially equal to that indicated by the value of said second signal when the first signal exceeds said threshold and the second signal indicates a rate higher than said predetermined rate; and (D) to increase said pacing rate above said predetermined pacing rate solely in response to increase in said second signal.
Claim 29
Dependent Claim
193 words
A pacemaker comprising: sensing means for providing a first signal which changes relatively rapidly in response to changes in a patient's exercise level but may inaccurately represent the pacing rate appropriate to said exercise level and a second signal which changes relatively slowly in response to changes in exercise level but, after having changed, relatively accurately represents the required pacing rate; and control means for controlling pacing rate in response to said sensing means, said control means being operative: (A) to provide a relatively low pacing rate when said first signal has a value less than a threshold; (B) to provide a predetermined pacing rate higher than said relatively low rate when the first signal exceeds said threshold and the second signal has a value indicative of a pacing rate less than said predetermined rate; (C) to provide a pacing rate substantially equal to that indicated by the value of said second signal when the first signal exceeds said threshold and the second signal indicates a rate higher than said predetermined rate; and (D) to increase said pacing rate above said predetermined pacing rate solely in response to increase in said second signal.
Claim 30
Dependent Claim
23 words
A pacemaker according to claim 24, wherein said predetermined rate is at least 20 beats per minute above said relatively low pacing rate.
Claim 31
Dependent Claim
24 words
A pacemaker according to claim 19, wherein said predetermined rate is between 20 and 30 beats per minute above said relatively low pacing rate.
Claim 32
Dependent Claim
21 words
A pacemaker according to claim 26, wherein said predetermined rate is approximately 25 bears per minute above said low pacing rate.
Claim 33
Dependent Claim
214 words
A pacemaker comprising: first sensing means for providing a first signal in response to bodily vibrations arising from a patient's activity; second sensing means for providing a second signal which changes in response to a physiological parameter which varies in response to a patient's activity; and control means for controlling pacing rate in response to said sensing means, said control means being operative: (A) to define for said first signal a threshold for components of said first signal having a frequency of at least 7Hz; (B) to provide a relatively low pacing rate when said first signal is such that said threshold is not exceeded; (C) to provide a predetermined pacing rate which is from 20 to 30 beats/min higher than said relatively low rate when the first signal is such that said threshold is exceeded and the second signal has a value indicative of a pacing rate less than said predetermined rate; (C) to provide a pacing rate substantially equal to that indicated by the value of said second signal when the first signal is such that said threshold is exceeded and the second signal indicates a rate higher than said predetermined rate; and (D) to increase said pacing rate above said predetermined pacing rate solely in response to increase in said signal.
Claim 34
Dependent Claim
214 words
A pacemaker comprising: first sensing means for providing a first signal in response to bodily vibrations arising from a patient's activity; second sensing means for providing a second signal which changes in response to a physiological parameter which varies in response to a patient's activity; and control means for controlling pacing rate in response to said sensing means, said control means being operative: (A) to define for said first signal a threshold for components of said first signal having a frequency of at least 7Hz; (B) to provide a relatively low pacing rate when said first signal is such that said threshold is not exceeded; (C) to provide a predetermined pacing rate which is from 20 to 30 beats/min higher than said relatively low rate when the first signal is such that said threshold is exceeded and the second signal has a value indicative of a pacing rate less than said predetermined rate; (C) to provide a pacing rate substantially equal to that indicated by the value of said second signal when the first signal is such that said threshold is exceeded and the second signal indicates a rate higher than said predetermined rate; and (D) to increase said pacing rate above said predetermined pacing rate solely in response to increase in said signal.
References Cited (Backward Citations)
No citation records indexed.
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