Source: http://www.google.com/patents/US20020198462?dq=5179747
Timestamp: 2017-12-11 21:53:49
Document Index: 557153056

Matched Legal Cases: ['art 8', 'art 8', 'art 8', 'art 8', 'art 8', 'art 8', 'art 8']

Patent US20020198462 - Method and system for monitoring heart failure using rate change dynamics - Google Patents
A method of monitoring heart failure is provided. A baseline heart rate change value is determined, wherein the baseline heart rate change value comprises a speed at which a first initial heart rate changes to a second initial heart rate. At least one subsequent heart rate change value is also determined,...http://www.google.com/patents/US20020198462?utm_source=gb-gplus-sharePatent US20020198462 - Method and system for monitoring heart failure using rate change dynamics
Publication number US20020198462 A1
Also published as EP1385422A2, US6636762, WO2002087432A2, WO2002087432A3
Publication number 09843917, 843917, US 2002/0198462 A1, US 2002/198462 A1, US 20020198462 A1, US 20020198462A1, US 2002198462 A1, US 2002198462A1, US-A1-20020198462, US-A1-2002198462, US2002/0198462A1, US2002/198462A1, US20020198462 A1, US20020198462A1, US2002198462 A1, US2002198462A1
Original Assignee Begemann Malcolm J.
US 20020198462 A1
30. The program of claim 45, further comprising:
31. The program of claim 45, further comprising:
32. The program of claim 45, further comprising:
33. The program of claim 45, further comprising:
34. The program of claim 45, further comprising:
35. The program of claim 45, further comprising:
36. The program of claim 45, further comprising:
37. The program of claim 45, further comprising:
40. The program of claim 45, further comprising:
42. The program of claim 45 further comprising:
43. The program of claim 45 further comprising:
44. The program of claim 45 further comprising:
45. A computer usable medium including a program for monitoring heart failure, comprising:
47. The program of claim 45, further comprising:
48. The program of claim 45, further comprising:
49. The program of claim 45, further comprising:
50. The program of claim 45, further comprising:
52. The program of claim 45, further comprising:
53. The program of claim 45, further comprising:
54. The program of claim 53, further comprising:
55. The program of claim 54 further comprising:
57. The system of claim 29, further comprising:
58. The program of claim 45 further comprising:
59. The program of claim 45 further comprising:
60. The program of claim 45 further comprising:
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[0025]FIG. 5 is a block diagram illustrating components of an embodiment of the implantable medical device of FIG. 4, made in accordance with the present invention;
[0026]FIG. 6 is a graph illustrating one embodiment of heart rate changes being evaluated in accordance with the presenting invention;
[0027]FIG. 7 is a flow diagram of one embodiment of a method for monitoring heart rate changes in accordance with the present invention; and
[0028]FIG. 8 is a flow diagram of one embodiment of a method for monitoring heart rate changes in accordance with the present invention.
[0030]FIG. 1 is a simplified schematic view of one embodiment of implantable medical device (“IMD”) 10 of the present invention. IMD 10 shown in FIG. 1 is a pacemaker comprising at least one of pacing and sensing leads 16 and 18 attached to hermetically sealed enclosure 14 and implanted near human or mammalian heart 8. Pacing and sensing leads 16 and 18 sense electrical signals attendant to the depolarization and re-polarization of the heart 8, and further provide pacing pulses for causing depolarization of cardiac tissue in the vicinity of the distal ends thereof. Leads 16 and 18 may have unipolar or bipolar electrodes disposed thereon, as is well known in the art. Examples of IMD 10 include implantable cardiac pacemakers disclosed in U.S. Pat. No. 5,158,078 to Bennett et al., U.S. Pat. No. 5,312,453 to Shelton et al. or U.S. Pat. No. 5,144,949 to Olson, all of which are hereby incorporated by reference herein, each in its respective entirety.
[0032]FIG. 3 shows a block diagram illustrating the constituent components of IMD 10 in accordance with one embodiment of the present invention, where IMD 10 is a pacemaker having a microprocessor-based architecture. IMD 10 is shown as including activity sensor or accelerometer 11, which may be an accelerometer bonded to a hybrid circuit located inside enclosure 14. Activity sensor 11 typically (although not necessarily) provides a sensor output that varies as a function of a measured parameter relating to a patient's metabolic requirements. For the sake of convenience, IMD 10 in FIG. 3 is shown with lead 18 only connected thereto; similar circuitry and connections not explicitly shown in FIG. 3 apply to lead 16.
In some preferred embodiments of the present invention, IMD 10 may operate in various non-rate-responsive modes, including, but not limited to, DDD, DDI, WI, VOO and WT modes. In other preferred embodiments of the present invention, IMD 10 may operate in various rate-responsive, including, but not limited to, DDDR, DDIR, VVIR, VOOR and VVTR modes. Some embodiments of the present invention are capable of operating in both non-rate-responsive and rate responsive modes. Moreover, in various embodiments of the present invention IMD 10 may be programmably configured to operate so that it varies the rate at which it delivers stimulating pulses to heart 8 only in response to one or more selected sensor outputs being generated. Numerous pacemaker features and functions not explicitly mentioned herein may be incorporated into IMD 10 while remaining within the scope of the present invention.
IMD 10 may also be a pacemaker-cardioverter-defibrillator (“PCD”) corresponding to any of numerous commercially available implantable PCDs. Various embodiments of the present invention may be practiced in conjunction with PCDs such as those disclosed in U.S. Pat. No. 5,545,186 to Olson et al., U.S. Pat. No. 5,354,316 to Keimel, U.S. Pat. No. 5,314,430 to Bardy, U.S. Pat. No. 5,131,388 to Pless and U.S. Pat. No. 4,821,723 to Baker et al., all of which are hereby incorporated by reference herein, each in its respective entirety. FIGS. 4 and 5 illustrate one embodiment of IMD 10 and a corresponding lead set of the present invention, where IMD 10 is a PCD. In FIG. 4, the ventricular lead takes the form of leads disclosed in U.S. Pat. Nos. 5,099,838 and 5,314,430 to Bardy, and includes an elongated insulative lead body 1 carrying three concentric coiled conductors separated from one another by tubular insulative sheaths. Located adjacent the distal end of lead 1 are ring electrode 2, extendable helix electrode 3 mounted retractably within insulative electrode head 4 and elongated coil electrode 5. Each of the electrodes is coupled to one of the coiled conductors within lead body 1. Electrodes 2 and 3 may be employed for cardiac pacing and for sensing ventricular depolarizations. At the proximal end of the lead is bifurcated connector 6, which carries three electrical connectors, each coupled to one of the coiled conductors. Defibrillation electrode 5 may be fabricated from platinum, platinum alloy or other materials known to be usable in implantable defibrillation electrodes and may be about 5 cm in length.
[0047]FIG. 5 is a functional schematic diagram of one embodiment of implantable PCD 10 of the present invention. This diagram should be taken as exemplary of the type of device in which various embodiments of the present invention may be embodied, and not as limiting, as it is believed that the invention may be practiced in a wide variety of device implementations, including cardioverter and defibrillators which do not provide anti-tachycardia pacing therapies.
Detection of atrial or ventricular tachyarrhythmias, as employed in the present invention, may correspond to any of the various tachyarrhythmia detection algorithms presently known in the art. For example, the presence of an atrial or ventricular tachyarrhythmia may be confirmed by detecting a sustained series of short R-R or P-P intervals of an average rate indicative of tachyarrhythmia or an unbroken series of short R-R or P-P intervals. The suddenness of onset of the detected high rates, the stability of the high rates, and a number of other factors known in the art may also be measured at this time. Appropriate ventricular tachyarrhythmia detection methodologies measuring such factors are described in U.S. Pat. No. 4,726,380 issued to Vollmann, U.S. Pat. No. 4,880,005, issued to Pless et al. and U.S. Pat. No. 4,830,006, issued to Haluska et al., all hereby incorporated by reference herein, each in its respective entirety. An additional set of tachycardia recognition methodologies is disclosed in the article “Onset and Stability for Ventricular Tachyarrhythmia Detection in an Implantable Pacer-Cardioverter-Defibrillator” by Olson et al., published in Computers in Cardiology, Oct. 7-10,1986, IEEE Computer Society Press, pages 167-170, also incorporated by reference herein in its entirety. Atrial fibrillation detection methodologies are disclosed in Published PCT Application Ser. No. US92/02829, Publication No. WO92/18198, by Adams et al., and in the article “Automatic Tachycardia Recognition”, by Arzbaecher et al., published in PACE, May-June, 1984, pp. 541-547, both of which are hereby incorporated by reference herein, each in its respective entirety.
Alternatively, circuitry for controlling the timing and generation of anti-tachycardia pacing pulses as described in U.S. Pat. No. 4,577,633, issued to Berkovits et al. on Mar. 25,1986, U.S. Pat. No. 4,880,005, issued to Pless et al. on Nov. 14, 1989, U.S. Pat. No. 4,726,380, issued to Vollmann et al. on Feb. 23,1988 and U.S. Pat. No. 4,587,970, issued to Holley et al. on May 13, 1986, all of which are hereby incorporated herein by reference, each in its respective entirety, may also be employed.
[0064]FIG. 6 shows a graph illustrating the operation of one embodiment of the present invention, where a baseline change in heart rate monitored by IMD 10 is compared to a subsequent change in heart rate, at 600. In one embodiment of the present invention, a subsequent change in heart rate which is significantly higher.
For example, in one embodiment of the invention, the heart rate is measured at fixed time intervals during time period 600. Thus, measurements may be taken, for example, at intervals ranging, without limitation, from every ten seconds, every twenty seconds, every thirty seconds or every 100 seconds. Alternatively, the measurements may be taken for example, at intervals ranging, without limitation, from every 5 minutes, every ten minutes, every 20 minutes, etc. Additionally, more than one timing interval could be taken (including, without limitation, every 10, 20, 30 and 60 seconds or every 10, 20, 30 and 60 minutes). In one embodiment of the invention, different measurements may be taken by sampling every x seconds with the resulting heart rate-change being a value calculated by subtracting every subsequent sample from the previous one
i.e., heart rate = current heart − previous heart rate
change rate value (n) value (n − 1)
Alternatively, different measurements may be taken by sampling every x seconds with the resulting heart rate-change being a value calculated by subtracting every subsequent sample from a sample that is y samples ago.
i.e., heart rate = current heart − earlier heart rate
change rate value (n) value (n − y)
[0091]FIG. 7 illustrates one embodiment of a method for monitoring a human heart in accordance with the teachings of the present invention. As discussed above, the method of the present invention may be performed under the control of any appropriate computer algorithm stored in a memory or a portion of a memory of microcomputer 58 in IMD 10. Such a computer algorithm may be any program capable of being stored in an electronic medium such as, by way of example only, RAM 68 or ROM 70 of IMD 10, where the contents of RAM 68 and ROM 70 may be accessed and consequently executed by microprocessor 64/microcomputer 58.
At block 720, a baseline heart rate change 610 is determined. This heart rate change may be, for example, the change in heart rate from the first measurement of initial heart rate to the second measurement of initial heart rate. The heart rate change value may be expressed in any suitable manner, for example, as a function over time, e.g., a 25 bpm change over 40 minutes, as a constant, e.g. a 0.625 heart rate change value, or as a percentage, a 62.5% change in heart rate. In one embodiment of the invention, different measurements may be taken by sampling every x seconds with the resulting heart rate-change being a value calculated by subtracting every subsequent sample from the previous one
Alternatively, different measurements may be taken by sampling every x seconds with the resulting heart rate-change with the resulting heart rate-change being a value calculated by subtracting every subsequent sample from a sample that is y samples ago.
The value measured at block 725 may provide another heart rate value for comparison to the value found at blocks 710 or 715. This too, may be, for example, an automatic or routine measurement. For example, IMD 10 may monitor the heart rate of heart 8 in a manner described above. Alternatively, this may be a value measured by the physician or under previously determined conditions set by the set by a physician, selected from a look-up table or database, or calculated (e.g., the measurement taken at block 725 may be taken once every day or after exercise.).
At block 732, the updated values from block 730 are subsequently stored in specific time slots, resulting in an overview of these values over time, with each time slot having its own stored values (average, maximum, minimum etc.).
[0106]FIG. 8 illustrates one embodiment of a method for monitoring a human heart in accordance with the teachings of the present invention. As discussed above, the method of the present invention may be performed under the control of any appropriate computer algorithm stored in a memory or a portion of a memory of microcomputer 58 in IMD 10. Such a computer algorithm may be any program capable of being stored in an electronic medium such as, by way of example only, RAM 68 or ROM 70 of IMD 10, where the contents of RAM 68 and ROM 70 may be accessed and consequently executed by microprocessor 64/microcomputer 58.
At block 820, a baseline heart rate change 610 is determined. This heart rate change may be, for example, the change in heart rate from the first measurement of initial heart rate to the second measurement of initial heart rate. The heart rate change value may be expressed in any suitable manner, for example, as a function over time, e.g., a 25 bpm change over 40 minutes, as a constant, e.g. a 0.625 heart rate change value, or as a percentage, a 62.5% change in heart rate. In one embodiment of the invention, different measurements may be taken by sampling every x seconds with the resulting heart rate-change being a value calculated by subtracting every subsequent sample from the previous one
At block 825, a subsequent heart rate of heart 8 may be measured. This may be, for example, an automatic or routine measurement. For example, IMD 10 may monitor the heart rate of heart 8 in a manner described above. Alternatively, this may be a value measured by the physician or under previously determined conditions set by the set by a physician, selected from a look-up table or database, or calculated (e.g., the measurement taken at block 725 may be taken once every day or before exercise.).
The value measured at block 825 may provide another heart rate value for comparison to the value found at blocks 710 or 715. This too, may be, for example, an automatic or routine measurement. For example, IMD 10 may monitor the heart rate of heart 8 in a manner described above. Alternatively, this may be a value measured by the physician or under previously determined conditions set by the set by a physician, selected from a look-up table or database, or calculated (e.g., the measurement taken at block 825 may be taken once every day or after exercise.).
International Classification A61N1/362, A61B5/0245, A61N1/372, G06F17/00
Cooperative Classification A61N1/3622, A61B5/02405, A61B5/0245, A61N1/3627