Abstract:
A system for generating a pacing vector selection table is configured to sense a heart sound signal and to represent sounds generated by the heart of the patient. A processor is configured to control the sequential selection (204) of pacing electrode vectors from electrodes positioned along a heart chamber. The processor is configured to receive (208) the heart sound signal, determine ((210), (212), (214), (216), (218), (220)) a plurality of different pacing responses using the heart sound signal for each of the pacing electrode vectors and generate (224) a pacing vector selection table listing the plurality of different pacing responses for each of the plurality of pacing electrode vectors.
Abstract:
Generally, the disclosure is directed one or more methods or systems of cardiac pacing employing a right ventricular electrode and a plurality of left ventricular electrodes. Pacing using the right ventricular electrode and a first one of the left ventricular electrodes and measuring activation times at other ones of the left ventricular electrodes. Pacing using the right ventricular electrode and a second one of the ventricular electrodes and measuring activation times at other ones of the left ventricular electrodes. Employing sums of the measured activation times to select one of the left ventricular electrodes for delivery of subsequent pacing pulses.
Abstract:
An implantable device and associated method detect anodal capture during electrical stimulation. A first pacing pulse is delivered using a first cathode and a first anode. A second pacing pulse is delivered using the first cathode and a second anode. A first response to the first pacing pulse and a second response to the second pacing pulse are measured. Anodal capture of the first pacing pulse at the first anode is detected in response to a first difference between the first response and the second response.
Abstract:
Electrical crosstalk between two implantable medical devices or two different therapy modules of a common implantable medical device may be evaluated, and, in some examples, mitigated. In some examples, one of the implantable medical devices or therapy modules delivers electrical stimulation to a nonmyocardial tissue site or a nonvascular cardiac tissue site, and the other implantable medical device or therapy module delivers cardiac rhythm management therapy to a heart of the patient.
Abstract:
Methods and devices that are configured to deliver cardiac stimuli in a particular fashion. In an illustrative embodiment, a method is used wherein a first stimulus is delivered using a first polarity, and, if the first stimulus fails to successfully convert an arrhythmia, a second stimulus having a second polarity that is different from or opposite of the first polarity is then delivered. Subsequent stimuli, if needed, are delivered in a continuing alternating-polarity manner. The first polarity may be determined by observing whether successfully-converting stimulus has been delivered previously and, if so, the polarity of the most recent stimulus that resulted in successful conversion is used as the first polarity. In additional embodiments, electrode configuration may be changed instead of or in addition to polarity, following unsuccessful stimulus delivery. Devices configured to perform such methods are included in additional illustrative embodiments.
Abstract:
A medical system comprises a plurality of electrodes; at least one sensor configured to output at least one signal based on at least one physiological parameter of a patient; and a processor. The processor is configured to control delivery of stimulation to the patient using a plurality of electrode configurations. Each of the electrode configurations comprises at least one of the plurality of electrodes. For each of the electrode configurations, the processor is configured to determine a first response of target tissue to the stimulation based on the signals, and a second response of non-target tissue to the stimulation based on the signals. The processor is also configured to select at least one of the electrode configurations for delivery of stimulation to the patient based on the first and second responses for the electrode configurations. As examples, the target tissue may be a left ventricle or vagus nerve.
Abstract:
A method and apparatus for treatment of an eating disorder includes electrically, mechanically and/or pharmaceutically/chemically stimulating a of the vagus nerve of the lower esophagus, cardia, esophageal/cardia junction, cardia/fundus junction or upper stomach so as to induce afferent action potentials on the vagus nerve. The device may be noninvasively adjusted after implantation to provide increased or decreased restriction on the patient's gastrointestinal tract. Each stimulus may be administered as a series of programmed pulses of defined amplitude, duration and period, to evoke a responsive signal to the brain by the target nerve, effective for producing a temporary feeling of satiety in the person. An implantable stimulus generator may be operatively coupled to a nerve electrode, pressure device or chemical outlet to apply a defined signal to a selected nerve branch. The implantable stimulus generator is programmable to allow clinician programming of defined signal parameters effective to treat the eating disorder of the patient. Methods are also provided to identify electrodes nearest to a branch of the vagus nerve to apply an electrical stimulation signal with improved efficiency.
Abstract:
Systems and methods sense electrical events about a selected annulus region (26, 30) of the heart (10) to identify the location of an accessory pathway. They establish a contact site between heart tissue and a multi-electrode array (E1-E10) conforming to the circumferential geometry of the selected annulus region (26, 30). The system and methods maintain this site, while conveying signals representing electrical events sensed by bipolar pairs of the electrodes (E1-E10). The systems and methods display the signals as graphic information that represents the time differences (T1, T2) between the atrium (A) and ventricular (V) electrogram complexes sensed by the pairs (E1-E10) on the selected annulus region (26, 30). The pairs (E1-E10) displaying the least time separation between the complexes (A, V) identifies the region of the accessory pathway. With this information, energy is conveyed to the electrodes of the selected pair to ablate tissue.
Abstract:
A method and apparatus for providing an enhanced capability of detecting and gathering electrical cardiac signals via an array of relatively closely spaced subcutaneous electrodes (located on the body of an implanted device) which may be employed with suitable switching circuits, signal processors, and memory to process the electrical cardiac signals between any selected pair or pairs of the electrode array in order to provide a leadless, orientation insensitive means for receiving the electrical signal from the heart. This far-field EGM may be used to provide storage and analysis of arrhythmic events and to provide control signals for the delivery of various therapies including pacing, cardioversion and defibrillation therapies as well as the delivery of antiarrhythmic drugs, and, in the pacing context, to effect capture detection and automatic stimulation threshold adaptation, recording of PMT episodes, measurement of refractory periods in order to set timing windows for antitachy pacing therapies, and as a control signal for use in adjusting pacing rate to physiologic demand. The housing or case of the subcutaneously implanted medical device is modified to provide an array of electrodes which may be selectively or sequentially coupled in one or more pairs to the terminals of one or more sense amplifiers to pick up, amplify and process the electrical cardiac signals across each electrode pair. In one embodiment, the signals from the selected electrode pairs may be stored and compared to one another in order to determine the sensing vector which provides the largest cardiac signal (in a test mode). Following completion of the test mode, the system may employ the selected subcutaneous ECG signal vector for a number of applications. The implanted device possesses analog-to-digital conversion circuitry for sampling and converting the selected subcutaneous ECG signal to digital data which is stored in a recirculating buffer, the contents of which are transferred to RAM for later data retrieval either periodically or upon the occurrence of an event of interest. In another embodiment, the selected subcutaneous ECG signal is used to confirm capture in conjunction with an algorithm for determining the stimulation threshold of the heart and set stimulation pulse energy at a level exceeding the threshold by a desired safety margin. Further embodiments include replacing the switching approach with parallel linear and nonlinear combinational processing of the signals from the orthogonal electrode pairs of the electrode array, to develop and employ continuous signals insensitive to the orientation variations of the electrode array. These linear and nonlinear embodiments would be used for improving the data storage and autocapture embodiments by providing an optimal signal at all times, while avoiding the switching process.