Source: https://patents.google.com/patent/US20110087119A1/en
Timestamp: 2018-07-16 21:14:19
Document Index: 83710302

Matched Legal Cases: ['art.\n2', 'art.\n3', 'art.\n5', 'art.\n9', 'art.\n11', 'art.\n12']

US20110087119A1 - Method and device for using impedance measurements based on electrical energy of the heart - Google Patents
US20110087119A1
US20110087119A1 US12857140 US85714010A US20110087119A1 US 20110087119 A1 US20110087119 A1 US 20110087119A1 US 12857140 US12857140 US 12857140 US 85714010 A US85714010 A US 85714010A US 20110087119 A1 US20110087119 A1 US 20110087119A1
US8219198B2 (en )
This application is a continuation of and claims priority from U.S. patent application Ser. No. 11/104,389, filed Apr. 11, 2005, which is a continuation-in-part of U.S. patent application Ser. No. 10/622,184, filed Jul. 16, 2003, and which is a continuation-in-part of U.S. patent application Ser. No. 10/155,771, filed May 25, 2002, now U.S. Pat. No. 6,829,503, that claims priority of DE 10148440-2, filed Oct. 1, 2001.
FIG. 12 is a flow diagram of the principles and signal processing of the present invention. An EKG signal sensor 45 consists of electronic means that makes connection with the site where the EKG signal is sensed either merely on an intracardiac basis, from a bipolar electrode, from a unipolar electrode (one electrode in the heart and one on the case), or from separate electrodes on an implantable case such as surface-mounted electrodes on a pacemaker, a defibrillator, or monitoring device that is preferably implanted subcutaneously, or implanted in a different location in the body as described in the cross-referenced related applications. At least bipolar EKG signals are sensed, and by a switching relay process 46 a load 6 is either added or not added to the signal circuitry. Thereby, two different EKG derived information signals are available for EKG amplifier and processor 47, one signal with and one signal without the load. Comparator and analyzer 48 derive the desired information from the quotient of the two impedances that correspond to voltages and impedances derived from a high and a low input impedance. This information is then provided on either a filtered or processed basis to storage medium 49 in which several long term, short term, and derivatives of the signals can be stored. Comparator 50 finally derives the information that is required to the respective implantable device either for a rate profile adjustment and optimization 51, or if it is only for monitoring purposes, for congestive heart failure 52 as described as one of exemplary embodiments in the aforementioned related '184 patent application. This telemonitoring signal can be telemetered to an outside device or through telemetry 53 or can also provide patient alert 54 in case of detecting a deviation from the desired pattern for the individual patient. Electronic means applied are state of the art, with switching relay process, EKG signal sensor, amplifier processor, analyzer, storage and comparator provided either in a single chip or the like, or in conventional electronic components applying a combination of digital and analog techniques or in solely digital techniques including filtering and effecter 55 that converts the available information into the desired action within the device.
1. A method of evaluating the cardio-circulatory and ventilatory condition of a patient, which comprises the step of determining the patient's thoracic impedance based on information solely derived from the electrical energy generated by the patient's own heart.
2. A method of adjusting the heart rate of a patient by means of an implantable rate adaptive pacemaker, said method comprising the step of adjusting the pacing rate of said pacemaker in response to a determination of the patient's intrinsic impedance derived solely from the electrical energy generated by the patient's heart.
3. The method of claim 2, including a step of closed loop optimization of said rate adaptive pacemaker to achieve said adjustment of pacing rate.
4. A method of monitoring the cardiocirculatory status of a patient with an implantable device, said method comprising the step of calculating the patient's impedance based on information derived from the electrical energy generated by the patient's own heart.
5. The method of claim 4, wherein said implantable device is implanted subcutaneously.
6. The method of claim 4, wherein said device is adapted to monitor the patient's EKG, and including the step of deriving changes in said impedance based on differential signal processing of said EKG.
7. The method of claim 6, including the step of applying information concerning said impedance changes within said device to determine the cardiocirculatory status of the patient.
8. The method of claim 4, wherein the patient is suffering from heart failure, and said device is adapted to monitor the patient's heart failure by performing said calculation of impedance and processing thereof solely using said electrical energy generated by the patient's own heart.
9. The method of enhancing the function of a body-implantable defibrillator, which comprises the steps of determining the impedance between sensing electrodes of said defibrillator, and changes in said impedance, based on energy generated by the heart of the patient in whom said defibrillator is implanted.
10. A device for evaluating the cardio-circulatory condition of a patient, said device comprising means for determining the patient's thoracic impedance based on information solely derived from the electrical energy generated by the patient's own heart.
11. The method of obtaining information about the cardiac function of a patient, said method comprising continuously processing electrical signal information from an EKG during depolarization and repolarization of the patient's heart representing systole and diastole as different phases of the heart represented by said EKG, using electrical energy generated by the patient's own heart.
12. The method of claim 11, including analyzing the impedance of the patient's heart and its changes with systole from a point close to the T-Wave of the EKG signal, and deriving information on the diastolic status of the heart derived from an impedance signal close to the R-Wave of the EKG signal.
13. The method of claim 12, including using a comparison between systole and diastole to assess the cardio-circulatory status of the patient.
14. The method of claim 1, including using the patient's thoracic impedance information to optimize the function of a rate adaptive pacemaker.
15. The method of claim 1, including using the patient's thoracic impedance information to optimize monitoring of the patient's congestive heart failure.
16. The method of claim 2, including using the patient's intrinsic impedance information to adapt the heart rate of a rate adaptive pacemaker accordingly.
17. The method of claim 2, including using the patient's intrinsic impedance information instantaneously to influence the rate adaptation on an ongoing basis within minutes.
18. The method of claim 2, including using the patient's intrinsic impedance information in which long term rate and cardio-circulatory response determine the rate adaptation on a long term daily or monthly basis.
19. An implantable device for monitoring the cardio-pulmonary status of a patient, comprising means for determining the patient's thoracic impedance from EKG signal information acquired by the device using electrical energy generated by the patient's own heart.
US20110087119A1 true true US20110087119A1 (en) 2011-04-14
US8219198B2 US8219198B2 (en) 2012-07-10
US8219198B2 (en) 2012-07-10 grant