Abstract: A method for abating carbon monoxide in an exhaust stream may include injecting an amount of air into the exhaust stream to produce an air/exhaust mixture; measuring an air/fuel ratio of the air/exhaust mixture; reacting carbon monoxide in the air/exhaust mixture with oxygen in the presence of a catalyst to produce carbon dioxide to abate carbon monoxide in the air/exhaust mixture; measuring a temperature of the catalyst; and adjusting the amount of air injected into the exhaust stream based on the air/fuel ratio or the temperature of the catalyst.

Abstract: The above-described methods and apparatus are believed to be of particular benefit for patients suffering heart failure including cardiac dysfunction, chronic HF, and the like and all variants as described herein and including those known to those of skill in the art to which the invention is directed. It will understood that the present invention offers the possibility of monitoring and therapy of a wide variety of acute and chronic cardiac dysfunctions. The current invention provides systems and methods for delivering therapy for cardiac hemodynamic dysfunction via the innervated myocardial substrate receives one or more discrete pulses of electrical stimulation during the refractory period of said innervated myocardial substrate.

Abstract: Refractory period stimulation (RPS) disclosed herein includes apparatus and methods to enhance cardiac performance by delivering monophasic stimulation pulses during the refractory period. The disclosure describes several system level improvements to RPS that include one or more of the following: (i) Delivery of RPS therapy pulses at multiple sites in an automatically alternating way to avoid increasing demand at any one location for prolonged periods of time. (ii) Delivery of RPS therapy pulses at multiple sites to determine one or more optimal electrode configurations for chronic RPS therapy delivery. (iii) Use of separate electrode(s) for sensing ventricular activity to properly time and adjust the application of RPS thereby avoiding limitations associated with electrode polarization that occurs due to the amount of energy delivered during the RPS. (iv) Use of a relatively long active recharge pulse at the RPS stimulation electrodes to remove the undesirable effects of polarization.

Abstract: In general, the disclosure describes implantable pulse generators (IPGs) adapted to deliver stimulation to refractory myocardial tissue. An IPG nominally delivers one to six monophasic stimulation pulses. Because monophasic stimulation tends to accumulate polarization, a programmable blanking period of between about 20 milliseconds (ms) and about 300 ms is implemented (subsequent to delivery of the last pulse in a RPS pulse train) to allow recovery from polarization. The stimulation pulse width is about 0.03 ms to about 1.6 ms and voltage amplitude of 0.5 volts to 8 volts at about 50 Hz. The amplitude of electrical current of the stimulation pulses is less than or equal to approximately 50 milliamps. The pulses are delivered to multiple sites within a cardiac chamber and device performance and/or diagnostic information can be stored within a memory structure and reviewed to confirm delivery of a desired therapy regimen.

Abstract: Methods and systems for treating patients with diastolic heart failure (DHF) are disclosed which include slowing a patient's heart rate below its intrinsic rate, and controlling the rate using cardiac pacing therapy to improve LV filling and cardiac output. In certain embodiments, a pacing treatment rate may be determined by adjusting an adaptive rate by an amount determined by evaluating one or more patient parameters.

Abstract: A method of controlling pulmonary capillary pressure is disclosed which includes increasing the output of a first ventricle (V1) (e.g., a left ventricle) relative to second ventricle (e.g., right ventricle) by increasing the magnitude of a post extrasystolic potentiation (PESP) therapy effect in the first ventricle relative to the magnitude of a PESP therapy effect produced in the second ventricle. In certain embodiments of the invention, this may be accomplished by adjusting the extra-stimulus interval (ESI) in either or both of the left ventricle and the right ventricle, for example.

Abstract: A method comprising sensing a blood pressure signal, deriving a hemodynamic measure from the sensed blood pressure signal, adjusting an extra systolic stimulation control parameter in response to the hemodynamic measure, and delivering extra systolic stimulation pulses according to the adjusted control parameter. The sensed blood pressure signal may be a ventricular or arterial blood pressure signal from which an estimated cardiac output, end diastolic pressure, mean pressure or any other hemodynamic measure is derived. Adjusting the extra systolic stimulation control parameter may include adjusting a pacing rate, a pacing interval, an extra systolic stimulation ratio, an extra systolic stimulation interval or enabling or terminating the extra systolic stimulation.

Abstract: An implantable medical device (IMD) includes a therapy circuit for delivering atrial pacing and a control circuit for detecting a return to sinus rhythm, determining the duration of atrial arrhythmia preceding the return to sinus rhythm, and controlling the therapy circuit to deliver transient atrial pacing based on the duration.

Abstract: A method of evaluating ventricular performance of a heart employing sensors to measure a ventricular dimension signal and deriving indices of ventricular performance therefrom. Premature Shortening (PS) and Isovolumic Lengthening (IL) comprise two indices of ventricular performance determined from analysis of the left ventricular dimension signal during the transition from ventricular filling to ventricular ejection. Measured values of PS and IL are compared to other measured values or reference values to determine if ventricular performance has improved (or worsened). In some embodiments, the dimension sensors may comprise piezoelectric sonomicrometer crystals that operate as ultrasound transmitters and receivers. The sensors may be mounted in relation to a ventricle of the heart either temporarily or permanently, and may be configured either separately from or integrally with cardiac pacing leads.

Abstract: A method and device for delivering cardiac stimulation that includes a first electrode, positioned within a first chamber of a heart, sensing cardiac signals associated with the first chamber and capable of delivering stimulation to the first chamber, and a second electrode, positioned within a second chamber of the heart, sensing cardiac signals associated with the second chamber and capable of delivering stimulation to the second chamber. A processing unit processes the sensed signals and controls the stimulation delivery via the first electrode and the second electrode, determining whether a predetermined rhythm is detected in the first chamber, and delivering high-frequency burst pacing to the first chamber in response to a predetermined rate being sensed in the second chamber during the predetermined rhythm.

Abstract: A system and method for detecting and classifying cardiac arrhythmias based on cardiac pressure signals or the combination of cardiac electrical and cardiac pressure signals. A cardiac electrogram signal is sensed to derive a cardiac rate from which an arrhythmia detection is made when the cardiac rate meets arrhythmia detection criteria. An intracardiac pressure signal is sensed to derive an indicator of tachycardia based on an analysis of the pressure signal in either the time domain or frequency domain. The detected arrhythmia is classified as tachycardia or fibrillation based on the tachycardia indicator wherein the tachycardia indicator is compared to tachycardia detection criteria and the arrhythmia is classified as tachycardia if tachycardia detection criteria are met and the arrhythmia is classified as fibrillation if the tachycardia detection criteria are not met.

Abstract: Control of defibrillation therapy delivered by implantable medical devices (IMDS) using hemodynamic sensor feedback is disclosed. The hemodynamic sensor feedback allows for increased control over application of atrial defibrillation therapy. Specifically, the therapy is delivered when a fibrillation episode results in a discrete loss of hemodynamic function. Defibrillation therapy is thus withheld for hemodynamically benign arrhythmias.

Abstract: A medical device, e.g., an implantable medical device, delivers one or more neurally-excitable stimulation pulses to myocardial tissue during a period when the tissue is refractory. The width of the pulses is less than or equal to approximately one half millisecond. In some embodiments, the current amplitude of the pulses is less than or equal to approximately twenty milliamps. In exemplary embodiments, the medical device delivers a pulse train of six or fewer pulses separated from each other by an interval that is greater than or equal to approximately ten milliseconds. In some embodiments, the medical device delivers pulses according to a schedule stored in a memory, or as a function of a monitored physiological parameter of a patient, such as an intracardiac pressure. In some embodiments, the medical device suspends or withholds delivery of neurally-excitable based on detection of cardiac ischemia.

Abstract: The above-described methods and apparatus are believed to be of particular benefit for patients suffering heart failure including cardiac dysfunction, chronic HF, and the like and all variants as described herein and including those known to those of skill in the art to which the invention is directed. It will understood that the present invention offers the possibility of monitoring and therapy of a wide variety of acute and chronic cardiac dysfunctions. The current invention provides systems and methods for delivering therapy for cardiac hemodynamic dysfunction.