|Publication number||US3593718 A|
|Publication date||Jul 20, 1971|
|Filing date||Jul 13, 1967|
|Priority date||Jul 13, 1967|
|Publication number||US 3593718 A, US 3593718A, US-A-3593718, US3593718 A, US3593718A|
|Inventors||Krasner Jerome L, Nardella Paul|
|Original Assignee||Biocybernetics Inc|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (2), Non-Patent Citations (1), Referenced by (145), Classifications (7) |
|External Links: USPTO, USPTO Assignment, Espacenet|
Physiologically controlled cardiac pacer
US 3593718 A
United States Patent 1 swam 3,358,690 12/1967 Cohen Jerome L. Krasner Woburn;
Paul Nardella, Stougton, both of, Mass. 653,056
July 13, 1967 July 20, 197i Biocybernetics, Ilnc.
Inventors Appl. No. Filed Patented Assignee PHYSIOLOGICALLY CONTROLLED CARDIAC PACER 11 Claims, 5 Drawing Figs.
US. Cl 128/419 P Int. Cl A6ln 1/36 Field of Search 128/419- References Cited UNITED STATES PATENTS lMPEDANC LTAGE 3,433,228 3/l969 Keller,Jr
OTHER REFERENCES Myers et 21]., AMERICAN JOURNAL OF MEDICAL ELECTRONICS ()ct.-Dec., 1964, pp. 233-236 (copy in 128/419 P) Primary Examiner william E Kamm Attorney-Joseph Zallen FREQUENCY FREQUENCY CONVERTER CONSTANT CURRENT SOURCE CONVERTER /PULSE CONSTANT CURRENT SOURCE r RATIE OSCILLATOR DELAY PAIENTEU JULBO m1 SHEET 2 OF 2 I50msec 60msec A-V DELAY [0 VENTRICLE CONSTANT CURRENT TO ATRIUM EONSTANT CURRENT [FIG 4 PHYSIOLOGICALLY CONTROLLED CARDIAC PACER BACKGROUND OF INVENTION One may enumerate cardiac pacer classes in many ways depending upon the context of the point the author is trying to make. For this reason we choose to categorize pacers into the following classes: p-wave synchronous pacers, RF pacers and inductive-coupled pacers.
P-wave synchronous pacers function by detecting and amplifying the electrocardiographic p-wave and stimulating the ventricles via a delay mechanism. In this manner, heart rate is accommodated to the variations of the SA node.
Radio frequency cardiac stimulation provides a method free of the discomforts and dangers of long term, externally applied cardiac stimulation. This technique consists of transmitting electrical energy to the heart through radio waves via a two megacycle frequency generator and a transmitter antenna coil to a small receiving coil. Heart rate is externally controlled by the patient.
The inductive coupled pacer consists of a pulse generator, attached by a flexible lead to an external primary coil that is strapped to the skin over the implanted secondary coil, the ends of which are the myocardial electrodes. The pulse in the primary coil produces a pulse in the secondary coil by simple electromagnetic induction. Heart rate is externally controlled by the patient.
Artificial pacers are not self-regulatory. They are therapeutically applied to patients with disturbances of the conducting system. The origin of the conduction block may be from congenital heart disease, congenital AV block, surgical, or acquired nonsurgical block. In the latter case, the conduction system may thus be interrupted in myocarditis, endocarditis, coronary ischemia, tumor, sclerosis of the cardiac skeleton, fatty infiltration, uremia, and hemochromatosis, After the application of the artificial pacer, drugs are given to cause complete AV block. Under the influence of such drugs atrial fibrillation may occur. This would be disastrous for a p-wave synchrony pacer (an amplifier failure would give the same result).
A second limitation of present cardiac pacers arises from their inability to insure atrioventricular synchrony. It is a consequence of the artificial pacer that the need for atrioventricular synchronization arises. The procedure of applying the pacer does not include the excision of the sinoauricular node, thereby creating two cardiac pacers: the auricular, i.e., the SA node; and the ventricular, i.e., the artificial pacer. There is no guarantee that these pacers will beat in proper synchronization with one another.
A third limitation is concerned with automatically adjusting the intensity of stimulation to compensate for growths of fibrotic tissue around the myocardial electrodes.
SUMMARY OF INVENTION We have found that if the pacer frequency is controlled by one of several interrelated physiological functions, the heart rate will be accommodated to the needs of the organism. Such interrelated functions can be described as follows:
a. Vasoconstriction, tachycardia, increase in respiratory minute volume and increase in skeletal muscle tone.
b. Vasodilation, bradycardia, decrease in respiratory minute volume and decrease in skeletal muscle tone.
In either group, when one reaction is stimulated, it is followed by the occurrence of the other three reactions. For example, when an individual changes from the lying to the standing position, the venous return is reduced and a drop in arterial pressure occurs. The organism compensates by vasoconstriction (in both, arteries and veins) and by an increase of the heart rate. This reaction is always accompanied by an increase in respiratory minute volume and an increase in skeletal muscle tone. The opposite happens when an individual changes from the standing to the lying position. The resulting increase in blood pressure is compensated for by Vasodilation,
and simultaneously by bradycardia, decrease in respiratory minute volume and decrease in skeletal muscle tone. Similar reactions are observed during muscular exercise: Vasocon striction, tachycardia, increase in muscular tone.
We have found it preferable to use respiration as the controlling factor and for this purpose employ an impedance pneumograph. The waveform is converted into DC voltage which in turn fires a DC/pulse rate oscillator. The pulses are fed to either one constant current source which is connected to an electrode implanted in the ventricle of the heart or to two constant current sources, one connected to an electrode implanted in the atrium of the heart and the other delay-connected to the ventricle so that the atrium pulse is always ahead of the ventricle pulse.
The novel features ofthis invention include the enslavement of the cardiac frequency to a different physiological parame ter, the stimulation of both the atrium and the ventricle, the use with such dual stimulation of a delay which varies in accordance with atrial frequency, the use of a constant current source for stimulating the heart, and the use of the combination of an impedance/voltage converter, frequency/DC converter and DC/pulse rate oscillator.
This invention is applicable to a pacer for a so-called artifcial heart as well as a natural heart. The term cardiac pacer as used in the appended claims is intended to include an artificial heart.
BRIEF DESCRIPTION OF DRAWINGS FIG. I is a schematic block diagram illustrating the invention.
FIG. 2 is a graph of normal heart rate as a function of respiration rate.
FIG. 3 is a graph of heart rate as a function of atrioventricular delay.
FIG. 4 is a circuit diagram of one example of this invention.
FIG. 5 is a circuit diagram ofa constant current source.
SPECIFIC EXAMPLE OF INVENTION As illustrated in FIGS. 1 and 4, electrodes are placed on the chest and connected to an impedance/voltage converter 11. Examples of impedance/voltage converters are described in the book by .I. J. Nybor, Electrical Impedance Plethysmog raphy," the article, Quantitative Evaluation of the Impedance Spirometry in Man," by Baker, Geddes, and Hoff in American Journal of Medical Electronics," April-June 1965, pp. 73-77, and the article, The Measurement of Physiological Events by Impedance Change," by Geddes and Hoff in Proceedings of the San Diego Symposium for Biomedical Engineering," 1963, pp. l15l22. The output wave is then fed to a frequency/DC converter 112 to yield a DC voltage response to frequency. An example of a frequency/DC converter is described on pages 660-662 of the book, Electronic and Radio Engineering," by F. E. Terman, 4th edition, McGraw-Hill, 1955. This DC voltage is then fed to a DC/pulse rate oscillator 13. An example ofa DC/pulse rate oscillator is described in the article, A Two-Transistor Analog to Frequency Converter," by .l. L. Krasner, Electronic Design," Nov., I964, and also in block 1130f the circuit illustrated in FIG. 4 in the drawings. The frequency of pulses produced by oscillator 13 is dependent on the input DC voltage. The pulses are used in two ways with a constant current source to send impulses to the heart.
In one method illustrated by the dotted line in FIG. ll, the pulses are fed to a constant current source 17 to send impulses to an electrode implanted in the ventricle of the heart. An example of such a constant current source is illustrated in FIG. 5. In the other arrangement, delineated by the solid lines of FIG. I, the pulses are fed to two branches, one being a constant current source 14 whose impulses are sent to an electrode imbedded in the atrium of the heart. The other branch consists of a variable delay 115 before permitting the pulses to feed the constant current source 16 whose output is connected to an electrode imbedded in the ventricle of the heart. This latter arrangement provides atrioventricular synchronization. Pulse shape is controlled by block 18 as shown in FIG. 4. As shown in FIG. 3, the required delay for proper synchronization varies according to the heart rate. The atrial rate may exceed but never be less than the ventricular rate. However, the atria, when not fibrillating, must be in phase with the ventricles according to the graph of atrioventricular delay versus heart rate shown in FIG. 3.
Synchrony is obtained by designing the artificial pacer to set a pace slightly in excess of that pace the normal SA node would set. in this manner, the pacer artificially takes over the regulation of the atrium, i.e. increases the slope of the curve shown in FIG. 2. The ventricles are stimulated by a variable delay mechanism (consistent with FIG. 3) which operates by changing the temporal relation between two pulse generators, regulated by the same physiological parameters, as a function of their frequencies. (See block in FIG. 4) ln the case of atrial fibrillation, artificial atrial control is biologically overridden. Also, the atrial rate can never be less than the ventricular rate.
We have determined that there is no apparent difference between normal heart rate and pulse frequency response when the subject lies, sits, or stands, or does light muscular exercise. There is, however, significant difference between heart rate and pacer frequency response during hyperpnoea, and heavy muscular exercise, as well as during application of pressure on the carotid sinuses (carotid sinus reflex). Accordingly, the pacer is so designed that its frequency output can not be slowed below a selected output, as for example 60 pulses per minute, or increased above a selected maximum, as for example 160 pulses per minute. For this purpose a relaxation oscillator can be used whose frequency increases as a linear function of voltage. Thus, if only positive or ground signals are applied, the pacer will not fire at less than the relaxation frequency. The result is that extreme bradycardia is avoided.
The term pacer" is used in the title, abstract, specification and claims as the full equivalent of the generic term pacemaker to indicate a device for stimulating the heart with an alternating current to steady the heart or to reestablish the rhythm of an arrested heart, as defined in Websters Third New International Dictionary (Unabridged Copyright 1966). The term Pacemaker" is a registered trademark for one form of such device.
1. The combination ofa first means responsive to a separate but normally heart-related physiological function and a cardiac pacer, said means controlling the output frequency of said pacer and comprising in series an impedance/voltage converter, a frequency/DC converter, and a DC/pulse rate oscillalOf.
2. Claim 1 wherein said function is respiration.
3. Claim 1 wherein a constant current source connects said oscillator to said pacer.
4. Claim 1 wherein said pacer includes a first constant current source whose output is adapted for connection to the atrium, a second constant current source whose output is adapted for connection to the ventricle, and a second means for delaying the output of the second source with respect to the output of said first source.
5. Claim 4, wherein said second means provides a delay which is a function of artificially stimulated atrial frequency.
6. Claim 1 wherein said pacer comprises a first output adapted for connection to the atrium, a second output adapted for connection to the ventricle, and a second means for delaying the second output with respect to the first output.
7. Claim 6 wherein said second means provides a delay which is a function of artificially stimulated atrial frequency.
8. Claim 1 wherein said combination comprises an impedance/voltage converter, the output of which is fed to a frequency/DC converter, whose output voltage is fed to a DC/pulsc rate oscillator, which branches into two constant current sources; the output of one said source being adapted for connection to the atrium, the output of the second said source being adapted for connection to the ventricle; second means being provided for delaying the output of said second source with respect to the output of said first source.
9. Claim 8 wherein said second means provides a delay which is a function of artificially stimulated atrial frequency.
10. A cardiac pacer which includes two constant current sources, one whose output is adapted for connection to the atrium and a second whose output is adapted for connection to the ventricle; means being provided for delaying the output of said second source with respect to the output of said first source.
11. Claim 10, wherein said means provides a delay which is a function of artificially stimulated atrial frequency.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US3358690 *||Nov 18, 1964||Dec 19, 1967||Cohen Marvin M||Heart stimulator utilizing a pressuresensitive semiconductor|
|US3433228 *||May 6, 1966||Mar 18, 1969||Cordis Corp||Multimode cardiac pacer|
|1|| *||Myers et al., AMERICAN JOURNAL OF MEDICAL ELECTRONICS Oct.-Dec., 1964, pp. 233 236 (copy in 128/419 P)|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3709229 *||Feb 9, 1971||Jan 9, 1973||American Optical Corp||Free-running atrial and demand ventricular pacer|
|US3716059 *||Aug 24, 1970||Feb 13, 1973||Cardiac Resuscitator Corp||Cardiac resuscitator|
|US3746005 *||Jul 19, 1971||Jul 17, 1973||American Optical Corp||Constant energy heartbeat stimulating apparatus with pulse width control|
|US3747604 *||Dec 6, 1971||Jul 24, 1973||American Optical Corp||Atrial and ventricular demand pacer with separate atrial and ventricular beat detectors|
|US3773051 *||Mar 1, 1972||Nov 20, 1973||Research Corp||Method and apparatus for stimulation of body tissue|
|US3783878 *||Dec 6, 1971||Jan 8, 1974||American Optical Corp||Atrial and ventricular pacer having independent rate and av delay controls|
|US3794045 *||Dec 6, 1971||Feb 26, 1974||American Optical Corp||Passive hysteresis circuit demand pacer|
|US3807410 *||Nov 19, 1971||Apr 30, 1974||American Optical Corp||Adaptive demand pacer|
|US3845773 *||Jul 7, 1972||Nov 5, 1974||Ass Rech Et D Entraide Cardiol||Cardiac stimulators|
|US3882851 *||Aug 15, 1973||May 13, 1975||Systron Donner Corp||Impedance plethysmograph|
|US4009721 *||Apr 23, 1976||Mar 1, 1977||Pacer S.N.C. Of Cerchiai Vanna & C.||Artificial pacemaker|
|US4088138 *||Dec 29, 1975||May 9, 1978||Cardiac Resuscitator Corp.||Cardiac resuscitator and monitoring apparatus|
|US4114627 *||Dec 14, 1976||Sep 19, 1978||American Hospital Supply Corporation||Cardiac pacer system and method with capture verification signal|
|US4140132 *||Mar 23, 1978||Feb 20, 1979||Dahl Joseph D||Variable rate timer for a cardiac pacemaker|
|US4144891 *||Apr 20, 1977||Mar 20, 1979||Medtronic, Inc.||Heart stimulator lead set|
|US4165750 *||Mar 9, 1978||Aug 28, 1979||Aleev Leonid S||Bioelectrically controlled electric stimulator of human muscles|
|US4201219 *||Mar 3, 1978||May 6, 1980||Bozal Gonzalez Jose L||Cardiac pace-maker|
|US4202339 *||Dec 19, 1978||May 13, 1980||Alexander Wirtzfeld||Cardiac pacemaker|
|US4228803 *||Oct 6, 1978||Oct 21, 1980||Credit Du Nord International N.V.||Physiologically adaptive cardiac pacemaker|
|US4305396 *||Apr 16, 1979||Dec 15, 1981||Vitatron Medical B.V.||Rate adaptive pacemaker and method of cardiac pacing|
|US4397316 *||Sep 22, 1980||Aug 9, 1983||Medtronic, Inc.||Rate and A-V delay generator for heart pacemaker|
|US4527568 *||Dec 27, 1983||Jul 9, 1985||Vitafin N.V.||Dual chamber pacer with alternative rate adaptive means and method|
|US4543954 *||Oct 17, 1983||Oct 1, 1985||Purdue Research Foundation||Exercise responsive cardiac pacemaker|
|US4543955 *||Aug 1, 1983||Oct 1, 1985||Cordis Corporation||System for controlling body implantable action device|
|US4545380 *||Apr 16, 1984||Oct 8, 1985||Cordis Corporation||Method and apparatus for setting and changing parameters or functions of an implanted device|
|US4566456 *||Oct 18, 1984||Jan 28, 1986||Cordis Corporation||Apparatus and method for adjusting heart/pacer rate relative to right ventricular systolic pressure to obtain a required cardiac output|
|US4567892 *||Mar 10, 1983||Feb 4, 1986||Gianni Plicchi||Implantable cardiac pacemaker|
|US4576183 *||Sep 17, 1984||Mar 18, 1986||Gianni Plicchi||Electronic circuit for monitoring respiratory parameter for controlling operation of implantable medical device|
|US4596251 *||Oct 10, 1984||Jun 24, 1986||Gianni Plicchi||Minute ventilation dependent rate responsive pacer|
|US4694830 *||Sep 24, 1986||Sep 22, 1987||Siemens Aktiengesellschaft||Heart pacemaker with respiratory signal generation capability|
|US4697591 *||Jun 16, 1986||Oct 6, 1987||Siemens Aktiengesellschaft||Cardiac pacer for pacing a human heart and pacing method|
|US4702253 *||Oct 15, 1985||Oct 27, 1987||Telectronics N.V.||Metabolic-demand pacemaker and method of using the same to determine minute volume|
|US4712555 *||Mar 27, 1985||Dec 15, 1987||Siemens-Elema Ab||Physiologically responsive pacemaker and method of adjusting the pacing interval thereof|
|US4721110 *||Jul 24, 1985||Jan 26, 1988||Lampadius Michael S||Respiration-controlled cardiac pacemaker|
|US4726383 *||Oct 2, 1986||Feb 23, 1988||Purdue Research Foundation||Exercise-responsive cardiac pacemaker lead|
|US4730389 *||Aug 15, 1986||Mar 15, 1988||Medtronic, Inc.||Method for fabrication of an implantable hermetic transparent container|
|US4730618 *||Jun 16, 1986||Mar 15, 1988||Siemens Aktiengesellschaft||Cardiac pacer for pacing a human heart and pacing method|
|US4757815 *||Dec 17, 1986||Jul 19, 1988||Siemens Aktiengesellschaft||Heart pacemaker|
|US4771780 *||Jan 15, 1987||Sep 20, 1988||Siemens-Pacesetter, Inc.||Rate-responsive pacemaker having digital motion sensor|
|US4790318 *||Jun 16, 1986||Dec 13, 1988||Siemens Aktiengesellschaft||Cardiac pacer for pacing a human heart|
|US4791931 *||Aug 13, 1987||Dec 20, 1988||Pacesetter Infusion, Ltd.||Demand pacemaker using an artificial baroreceptor reflex|
|US4791935 *||Aug 15, 1986||Dec 20, 1988||Medtronic, Inc.||Oxygen sensing pacemaker|
|US4807629 *||Nov 19, 1987||Feb 28, 1989||Medtronic, Inc.||Oxygen sensing pacemaker|
|US4813421 *||Nov 19, 1987||Mar 21, 1989||Medtronic, Inc.||Oxygen sensing pacemaker|
|US4858611 *||Jun 3, 1987||Aug 22, 1989||Dimed, Inc.||Sensing system and method for sensing minute ventilation|
|US4860751 *||Feb 4, 1985||Aug 29, 1989||Cordis Corporation||Activity sensor for pacemaker control|
|US4884576 *||Sep 28, 1988||Dec 5, 1989||Eckhard Alt||Self adjusting rate responsive cardiac pacemaker and method|
|US4903701 *||Mar 10, 1988||Feb 27, 1990||Medtronic, Inc.||Oxygen sensing pacemaker|
|US4907593 *||May 21, 1987||Mar 13, 1990||Biocontrol Technology, Inc.||Adaptation of heart pacing to physical activity|
|US4919136 *||Sep 28, 1988||Apr 24, 1990||Eckhard Alt||Ventilation controlled rate responsive cardiac pacemaker|
|US4940053 *||Jan 25, 1989||Jul 10, 1990||Siemens-Pacesetter, Inc.||Energy controlled rate-responsive pacemaker having automatically adjustable control parameters|
|US5003976 *||Sep 28, 1988||Apr 2, 1991||Eckhard Alt||Cardiac and pulmonary physiological analysis via intracardiac measurements with a single sensor|
|US5010893 *||Mar 24, 1988||Apr 30, 1991||Siemens-Pacesetter, Inc.||Motion sensor for implanted medical device|
|US5036849 *||Apr 4, 1990||Aug 6, 1991||Cardiac Pacemakers, Inc.||Variable rate cardiac pacer|
|US5040534 *||May 30, 1990||Aug 20, 1991||Siemens-Pacesetter, Inc.||Microprocessor controlled rate-responsive pacemaker having automatic rate response threshold adjustment|
|US5040535 *||May 30, 1990||Aug 20, 1991||Siemens-Pacesetter, Inc.||Average amplitude controlled rate-responsive pacemaker having automatically adjustable control parameters|
|US5081988 *||Feb 26, 1991||Jan 21, 1992||Purdue Research Foundation||Exercise responive cardiac pacemaker|
|US5137019 *||Mar 1, 1991||Aug 11, 1992||Cardiac Pacemakers, Inc.||Variation in cardiac chamber volume or pressure as a controlling parameter|
|US5164898 *||Feb 10, 1992||Nov 17, 1992||Ricoh Company, Ltd.||System for determining hazardous substance exposure rate from concentration measurement and heart rate data|
|US5235976 *||Dec 13, 1991||Aug 17, 1993||Cardiac Pacemakers, Inc.||Method and apparatus for managing and monitoring cardiac rhythm using active time as the controlling parameter|
|US5282840 *||Mar 26, 1992||Feb 1, 1994||Medtronic, Inc.||Multiple frequency impedance measurement system|
|US5284136 *||May 13, 1991||Feb 8, 1994||Cardiac Pacemakers, Inc.||Dual indifferent electrode pacemaker|
|US5330510 *||Dec 22, 1992||Jul 19, 1994||Ela Medical||Pacemaker with patient effort-controlled frequency|
|US5391190 *||Apr 7, 1992||Feb 21, 1995||Cardiac Pacemakers, Inc.||Variation in cardiac chamber volume or pressure as a controlling parameter|
|US5429123 *||Dec 15, 1993||Jul 4, 1995||Temple University - Of The Commonwealth System Of Higher Education||Process control and apparatus for ventilation procedures with helium and oxygen mixtures|
|US5480441 *||Mar 30, 1994||Jan 2, 1996||Medtronic, Inc.||Rate-responsive heart pacemaker|
|US5522860 *||Dec 23, 1994||Jun 4, 1996||Ela Medical S.A.||Control of an active implantable medical device|
|US5674259 *||Oct 20, 1993||Oct 7, 1997||Gray; Noel Desmond||Multi-focal leadless apical cardiac pacemaker|
|US5792208 *||Jun 30, 1997||Aug 11, 1998||Gray; Noel Domond||Heart pacemaker|
|US5800470 *||Mar 11, 1996||Sep 1, 1998||Medtronic, Inc.||Respiratory muscle electromyographic rate responsive pacemaker|
|US5919210 *||Apr 10, 1997||Jul 6, 1999||Pharmatarget, Inc.||Device and method for detection and treatment of syncope|
|US5935153 *||Nov 20, 1997||Aug 10, 1999||Ela Medical S.A.||Active implantable medical device enslaved to a signal of acceleration|
|US5954757 *||Oct 1, 1997||Sep 21, 1999||Gray; Noel Desmond||Heart pacemaker|
|US6044300 *||Jun 30, 1997||Mar 28, 2000||Gray; Noel Desmond||Heart pacemaker|
|US6078834 *||Feb 25, 1999||Jun 20, 2000||Pharmatarget, Inc.||Device and method for detection and treatment of syncope|
|US6405738 *||Oct 22, 1999||Jun 18, 2002||Ultrafryer Systems, Inc.||Spray cleaning apparatus for deep fryer|
|US6519494||Aug 18, 2000||Feb 11, 2003||Biotronik Mess-Und Therapiegeraete Gmbh & Co. Ingenieurbuero Berlin||Rate-adaptive cardiac pacemaker|
|US6952610 *||Nov 5, 2001||Oct 4, 2005||Cameron Health, Inc.||Current waveforms for anti-tachycardia pacing for a subcutaneous implantable cardioverter- defibrillator|
|US7062326||Feb 6, 2003||Jun 13, 2006||Cardiac Pacemakers, Inc.||Method and apparatuses for monitoring hemodynamic activities using an intracardiac impedance-derived parameter|
|US7092757||Jul 12, 2002||Aug 15, 2006||Cardiac Pacemakers, Inc.||Minute ventilation sensor with dynamically adjusted excitation current|
|US7101339||Dec 13, 2002||Sep 5, 2006||Cardiac Pacemakers, Inc.||Respiration signal measurement apparatus, systems, and methods|
|US7133718||Jun 19, 2003||Nov 7, 2006||Medtronic, Inc.||Method and apparatus for temporarily varying a parameter in an implantable medical device|
|US7200440||Jul 2, 2003||Apr 3, 2007||Cardiac Pacemakers, Inc.||Cardiac cycle synchronized sampling of impedance signal|
|US7218964 *||Oct 26, 2001||May 15, 2007||Medtronic, Inc.||Closed-loop neuromodulation for prevention and treatment of cardiac conditions|
|US7628757||May 25, 2005||Dec 8, 2009||Pacesetter, Inc.||System and method for impedance-based detection of pulmonary edema and reduced respiration using an implantable medical system|
|US7647106||Apr 23, 2003||Jan 12, 2010||Medtronic, Inc.||Detection of vasovagal syncope|
|US7813812||Jul 7, 2006||Oct 12, 2010||Cvrx, Inc.||Baroreflex stimulator with integrated pressure sensor|
|US7840271||Jul 20, 2005||Nov 23, 2010||Cvrx, Inc.||Stimulus regimens for cardiovascular reflex control|
|US7949400||Nov 10, 2009||May 24, 2011||Cvrx, Inc.||Devices and methods for cardiovascular reflex control via coupled electrodes|
|US8005539||Jan 30, 2009||Aug 23, 2011||Medtronic, Inc.||Implantable medical device crosstalk evaluation and mitigation|
|US8050764||Oct 29, 2003||Nov 1, 2011||Cardiac Pacemakers, Inc.||Cross-checking of transthoracic impedance and acceleration signals|
|US8060206||Jul 7, 2006||Nov 15, 2011||Cvrx, Inc.||Baroreflex modulation to gradually decrease blood pressure|
|US8086314||Oct 29, 2002||Dec 27, 2011||Cvrx, Inc.||Devices and methods for cardiovascular reflex control|
|US8197234 *||May 24, 2005||Jun 12, 2012||California Institute Of Technology||In-line actuator for electromagnetic operation|
|US8209011||Sep 17, 2007||Jun 26, 2012||Cardiac Pacemakers, Inc.||Automatically configurable minute ventilation sensor|
|US8249708||Jan 30, 2009||Aug 21, 2012||Medtronic, Inc.||Implantable medical device crosstalk evaluation and mitigation|
|US8260412||Jan 30, 2009||Sep 4, 2012||Medtronic, Inc.||Implantable medical device crosstalk evaluation and mitigation|
|US8290595||Jul 7, 2006||Oct 16, 2012||Cvrx, Inc.||Method and apparatus for stimulation of baroreceptors in pulmonary artery|
|US8306621||Feb 16, 2007||Nov 6, 2012||Cardiac Pacemakers, Inc.||Cardiac cycle synchronized sampling of impedance signal|
|US8315713||Apr 30, 2009||Nov 20, 2012||Medtronic, Inc.||Techniques for placing medical leads for electrical stimulation of nerve tissue|
|US8412320||Aug 17, 2005||Apr 2, 2013||Cameron Health, Inc.||Nontransvenous and nonepicardial methods of cardiac treatment and stimulus|
|US8423142||Oct 31, 2011||Apr 16, 2013||Cardiac Pacemakers, Inc.||Cross-checking of transthoracic impedance and acceleration signals|
|US8442633||Oct 30, 2012||May 14, 2013||Cardiac Pacemakers, Inc.||Cardiac cycle synchronized sampling of impedance signal|
|US8452394||Jan 30, 2009||May 28, 2013||Medtronic, Inc.||Implantable medical device crosstalk evaluation and mitigation|
|US8473057||Oct 30, 2009||Jun 25, 2013||Medtronic, Inc.||Shunt-current reduction housing for an implantable therapy system|
|US8498698||Aug 31, 2009||Jul 30, 2013||Medtronic, Inc.||Isolation of sensing and stimulation circuitry|
|US8527045||Oct 30, 2009||Sep 3, 2013||Medtronic, Inc.||Therapy system including cardiac rhythm therapy and neurostimulation capabilities|
|US8532779||Jan 30, 2009||Sep 10, 2013||Medtronic, Inc.||Implantable medical device crosstalk evaluation and mitigation|
|US8532793||Apr 30, 2009||Sep 10, 2013||Medtronic, Inc.||Techniques for placing medical leads for electrical stimulation of nerve tissue|
|US8560060||Aug 31, 2009||Oct 15, 2013||Medtronic, Inc.||Isolation of sensing and stimulation circuitry|
|US8583236||Mar 8, 2010||Nov 12, 2013||Cvrx, Inc.||Devices and methods for cardiovascular reflex control|
|US8606359||Apr 13, 2007||Dec 10, 2013||Cvrx, Inc.||System and method for sustained baroreflex stimulation|
|US8611996||Jan 30, 2009||Dec 17, 2013||Medtronic, Inc.||Implantable medical device crosstalk evaluation and mitigation|
|US8688210||Jan 30, 2009||Apr 1, 2014||Medtronic, Inc.||Implantable medical device crosstalk evaluation and mitigation|
|US8688214||May 10, 2013||Apr 1, 2014||Cardiac Pacemakers. Inc.||Cardiac cycle synchronized sampling of impedance signal|
|US8706217||Mar 30, 2012||Apr 22, 2014||Cameron Health||Cardioverter-defibrillator having a focused shocking area and orientation thereof|
|US8712531||May 24, 2012||Apr 29, 2014||Cvrx, Inc.||Automatic baroreflex modulation responsive to adverse event|
|US8718760||May 6, 2013||May 6, 2014||Cameron Health Inc.||Subcutaneous implantable cardioverter-defibrillator placement methods|
|US8718789||Apr 19, 2010||May 6, 2014||Cvrx, Inc.||Electrode structures and methods for their use in cardiovascular reflex control|
|US8744565||Apr 30, 2008||Jun 3, 2014||Medtronic, Inc.||Multi-frequency impedance monitoring system|
|US8750989||May 20, 2013||Jun 10, 2014||Cameron Health, Inc.||Apparatus and method for identifying atrial arrhythmia by far-field sensing|
|US8774918||Jan 30, 2009||Jul 8, 2014||Medtronic, Inc.||Implantable medical device crosstalk evaluation and mitigation|
|US8831720||Oct 25, 2013||Sep 9, 2014||Cameron Health, Inc.||Method of implanting and using a subcutaneous defibrillator|
|US8838246||Sep 27, 2006||Sep 16, 2014||Cvrx, Inc.||Devices and methods for cardiovascular reflex treatments|
|USRE30750 *||May 7, 1980||Sep 29, 1981||Cardiac Resuscitator Corporation||Cardiac resuscitator and monitoring apparatus|
|DE2252312A1 *||Oct 20, 1972||May 30, 1973||American Optical Corp||Herzschrittmacher mit bedarfsanpassung|
|DE2613463A1 *||Mar 30, 1976||Nov 4, 1976||Pacer Snc||Herzschrittmacher|
|DE2809091A1 *||Mar 2, 1978||Sep 7, 1978||Bozal Gonzalez Jose L||Herzschrittmacher|
|DE3428975A1 *||Aug 6, 1984||Feb 13, 1986||Michael S Lampadius||Atmungsgesteuerter herzschrittmacher|
|DE3914680A1 *||May 3, 1989||Nov 8, 1990||Alt Eckhard||Herzschrittmacher|
|EP0089014A2 *||Mar 10, 1983||Sep 21, 1983||Gianni Plicchi||Physiological implantable cardiac pacemaker in which the stimulation rate is regulated by the respiration rate of the patient|
|EP0096464A1 *||May 5, 1983||Dec 21, 1983||Purdue Research Foundation||Exercise responsive cardiac pacemaker|
|EP0147820A2 *||Dec 21, 1984||Jul 10, 1985||Vitatron Medical B.V.||Dual chamber pacer with alternative rate adaptive means|
|EP0151689A2 *||Oct 8, 1984||Aug 21, 1985||SCHIAPPARELLI MEDTRONIC S.p.A.||Minute ventilation dependent rate responsive pacer|
|EP0218007A1 *||Jun 11, 1986||Apr 15, 1987||Siemens Aktiengesellschaft||Heart pace maker|
|EP0249819A1||Jun 4, 1987||Dec 23, 1987||Pacesetter AB||Cardiac pacer for pacing a human heart|
|EP0249824A1||Jun 4, 1987||Dec 23, 1987||Pacesetter AB||A cardiac pacer for pacing a heart|
|EP0426775A1 *||Jan 22, 1990||May 15, 1991||Pacesetter, Inc.||Automatically adjustable energy controlled rate-responsive pacemaker|
|EP1078650A1||Aug 8, 2000||Feb 28, 2001||BIOTRONIK Mess- und Therapiegeräte GmbH & Co Ingenieurbüro Berlin||Rate adaptive pacemaker|
|EP2184011A1 *||Oct 13, 2009||May 12, 2010||Ela Medical||Medical device such as an implantable artificial heart, including spirometric means for diagnosing pulmonary pathologies|
|WO1986000234A1 *||Jun 20, 1985||Jan 16, 1986||Medtronic Inc||Process and apparatus for diaphragmic stimulation|
|WO1994008657A1 *||Oct 20, 1993||Apr 28, 1994||Noel Desmond Gray||A heart pacemaker|
|WO1995016484A1 *||Nov 15, 1994||Jun 22, 1995||Univ Temple||Process and apparatus for controlling helium/oxygen|
|WO1996036395A1 *||Mar 11, 1996||Nov 21, 1996||Medtronic Inc||Respiratory muscle electromyographic rate responsive pacemaker|
|WO2004112897A1||Jun 18, 2004||Dec 29, 2004||Bakken Earl E||Method and apparatus for temporarily varying a parameter in an implantable medical device|