Abstract: A first lead provides therapeutic stimulation to the heart and includes a first mechanical sensor that measures physical contraction and relaxation of the heart. A controller induces delivery of therapeutic stimulation via the first lead. The controller receives signals from the first mechanical sensor indicative of the contraction and relaxation; develops a template signal that corresponds to the contraction and relaxation; and uses the template signal to modify the delivery of therapeutic stimulations. In another arrangement, a second lead, with a second mechanical sensor also provides signals to the controller indicative of contraction and relaxation. The first mechanical sensor is adapted to be positioned at the interventricular septal region of the heart, and the second mechanical sensor is adapted to be positioned in the lateral region of the left ventricle. The controller processes the signals from the first mechanical sensor and the second mechanical sensor to develop a dysynchrony index.

Abstract: The present invention is a tool coupled to a hemostasis valve and adapted to slit/split a tubular body of a catheter or sheath to facilitate the removal of the tubular body from about a medical device extending through the hemostasis valve and tubular body. The tool comprises a conical barrel portion supporting one or more radially outward extending blades. The tool also comprises a stabilizing component for preventing displacement between the tool and medical device when the tubular body is being removed from about the medical device.

Abstract: A universal cable connector for detachably connecting a stimulation lead to a system analyzer includes a nonconductive connector block for releasably receiving and holding fixed a a proximate contact electrically in continuity with a distal electrode, a cable for selectively electrically interconnecting the proximate contact and the system analyzer, and a switch mechanism for selectively connecting electrically the system analyzer cable with the proximate contact thereby enabling the system analyzer to determine the efficacy of the chosen body tissue site. The connector block includes a nest region for receiving the proximal end of the lead and the switch mechanism includes a switch contact electrically engaged with the cable and movable between a first position disengaged from an associated and selected exposed proximate contact and a second position engaged with the proximate contact for electrically connecting the distal electrode to the system analyzer.

Abstract: An exemplary method includes implementing a nerve stimulation therapy that includes delivering stimulation energy to a target nerve, periodically acquiring compound action potentials responsive to the delivered stimulation energy and assessing condition of the target nerve based at least in part on the periodically acquired compound action potentials. Various other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: The implantable device is capable of performing thermal dilution analysis of the cardiac output of a patient using power delivered from an external source. By using power from an external source, the implantable device conserves its power resources for other purposes, such as for pacing or defibrillation therapy. In one example, an external programmer or bedside monitor provides power through a hand-held power delivery wand via electromagnetic induction, with the power routed from a subcutaneous coil to a heating element implanted in the right atrium, which heats blood as it passes through the right atrium. In another example, the heating element is formed of a material that generates heat in response to a beam of ultrasound provided by the wand. In either case, a downstream blood temperature profile is detected using a thermistor implanted in the pulmonary artery and cardiac output is then estimated by analyzing the temperature profile.

Abstract: In one implementation, a failsafe method for implantable satellite pacemaker pacing is provided, which includes pacing with a satellite pacemaker and monitoring for a local pacing pulse with an other satellite pacemaker. This implementation further includes, pacing with a surrogate satellite pacemaker if the local pacing pulse is not detected by the other satellite pacemaker. Certain implementations may include transmitting a wireless signal from the other satellite pacemaker to a master pacemaker if the local pacing pulse is not detected by the other satellite pacemaker and using the master pacemaker to select the surrogate satellite pacemaker. Certain implementations may include monitoring for the local pacing pulse with a plurality of satellite and causing the plurality of satellite pacemakers to select the surrogate satellite pacemaker.

Abstract: An exemplary method includes providing a mechanical activation time (MA time) for a myocardial location, the location defined at least in part by an electrode and the mechanical activation time determined at least in part by movement of the electrode; providing an electrical activation time (EA time) for the myocardial location; and determining an electromechanical delay (EMD) for the myocardial location based on the difference between the mechanical activation time (MA time) and the electrical activation time (EA time).

Abstract: A measurement light detector detects light transmitted by a light source of an implantable system that is scattered back into an implantable housing, and produces a measurement signal indicative of the intensity of the light detected by the measurement light detector. A calibration light detector detects a portion of the transmitted light that has not exited the housing, and produces a calibration signal that is indicative of the intensity of the light detected by the calibration light detector, which is indicative of the intensity of the light transmitted by the light source. Changes in the intensity of the transmitted light are compensated for based on the calibration signal produced by the calibration light detector. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

Abstract: Techniques are provided for detecting pulmonary edema based on a comparison of impedance-based respiratory patterns and impedance-based cardiac patterns, i.e. patterns derived from thoracic impedance signals. In one example, a numerical ratio is calculated between average peak-to-peak amplitudes of the respiratory patterns and average peak-to-peak amplitudes of the cardiac patterns. Pulmonary edema is detected if the amplitude ratio falls below a pulmonary edema detection threshold. Techniques are also provided for controlling operation of an impedance-based reduced respiration detector, i.e. a detector which seeks to detect apnea, hypopnea, or the like, based on analysis of respiratory patterns derived from a thoracic impedance signal.

Abstract: Techniques are provided for delivering cardiac pacing therapy to the heart of a patient using an epicardial left ventricular satellite pacing device in conjunction with primary pacemaker having at least a right ventricular pacing lead. In one embodiment described herein, right ventricular pulses generated by the primary pacemaker are detected by the satellite pacer and analyzed to determine the timing pattern employed by the primary pacemaker. The timing pattern is then used to specify the delivery times of epicardial left ventricular pulses so as to be synchronized with right ventricular pulses. In another embodiment described herein, the primary pacemaker modulates the right ventricular pulses to encode timing information, which is then detected and decoded by the satellite pacemaker. In this manner, biventricular pacing therapy, such as cardiac resynchronization therapy, may be conveniently delivered using a non-biventricular pacemaker in combination with an epicardial satellite pacer.

Abstract: Techniques are provided for estimating electrical conduction delays with the heart of a patient based on measured immittance values. In one example, impedance or admittance values are measured within the heart of a patient by a pacemaker or other implantable medical device, then used by the device to estimate cardiac electrical conduction delays. A first set of predetermined conversion factors may be used to convert the measured immittance values into conduction delay values. In some examples, the device then uses the estimated conduction delay values to estimate LAP or other cardiac pressure values. A second set of predetermined conversion factors may be used to convert the estimated conduction delays into pressure values. Techniques are also described for adaptively adjusting pacing parameters based on estimated LAP.

Abstract: An economical, repeatable, and non-invasive method and apparatus for the calibration of implantable pressure sensors that can minimize patient discomfort and risk of infection. In one embodiment, a calibration system for calibrating a first pressure sensor coupled to a management device and implanted into a human patient is provided. The calibration system includes a mouthpiece, a pump, a second pressure sensor, and a computer. The pump provides a positive pressure into an airway of the human patient via the mouthpiece. The second pressure sensor measures the airway pressure of the human patient, and the computer is coupled to the pump and monitors pressures measured by the first and second pressure sensors. Here, the computer also calculates one or more calibration constants based on the pressures measured by the first and second pressure sensors and provides the calibration constants to the management device to calibrate the first pressure sensor.

Abstract: Systems and methods for providing high voltage confirmation are disclosed. In various embodiments, impedance data can be used as a basis for determining the operation of a high voltage confirmation system. In some embodiments, measurements of impedance associated with the high voltage lead(s) can provide indication as to the condition of the lead(s). In some embodiments, faulty leads can yield impedance values that exceed a known threshold value. In some embodiments, such threshold value can be determined from a laboratory study of the leads under conditions that are similar to the operating conditions of implantable cardiac devices.

Abstract: Techniques are provided for use by a pacemaker or other implantable medical device for estimating optimal atrio-ventricular pacing delays within a patient. The inter-atrial conduction delays (IACDs) are determined based, at least in part, on atrial far-field (AFF) signals sensed using a multi-pole left ventricular (LV) lead, such as an LV lead implanted via the coronary sinus (CS) with a plurality of electrodes. In one example, for intrinsic atrial events, the IACD is equal to the interval from the beginning of a P-wave detected via a right atrial lead and the end (or peak) of an AFF event detected via a left atrial ring electrode of a CS/LV lead. For paced atrial events, the IACD is instead equal to the interval from the A-pulse to the end (or peak) of the AFF event detected via the CS/LV lead. AV/PV pacing delays are then calculated based on the IACD adjusted by an offset.

Abstract: Techniques are provided for evaluating and optimizing the contribution of particular heart chambers to pacing efficacy. Briefly, a pacemaker temporarily alters the mode with which pacing therapy is delivered so as to selectively alter the heart chambers that are paced. The pacemaker detects any transient changes in pacing efficacy following the alteration in pacing mode. The pacemaker then assesses the contribution of particular heart chambers to pacing efficacy based on the alteration in the pacing mode and on any transient changes in the pacing efficacy. Additionally, techniques are provided herein for automatically adjusting pacing parameters to optimize the contribution of particular chambers to pacing efficacy.

Abstract: An exemplary method includes providing a first value indicative of electrode polarization, delivering a cardiac stimulus and determining a second value indicative of electrode polarization associated with the cardiac stimulus, comparing the second value to the first value to determine whether a change in cardiac condition has occurred and, based at least in part on the comparing, deciding whether to adjust a cardiac stimulation therapy.

Abstract: This invention relates generally to apparatus and methods for the calibration of implanted pressure transducers. It is an object of several embodiments of the present invention to provide apparatus and methods for the calibration of one or more implanted pressure transducers implanted in the body of medical patients. Various embodiments of the present invention are particularly advantageous because they offer a calibration system that is less invasive than the systems currently available.

Abstract: An implantable medical device (IMD) is provided. The IMD comprises a sense circuit, a main processing unit coupled to the sense circuit, a memory unit coupled to the main processing unit, and a reconfigurable processor unit coupled to the memory unit and the main processing unit. The reconfigurable processor unit is adapted to receive data, perform a processing function on the data, and return processed data to the memory unit. The memory unit is adapted to store the processed data. The main processing unit is adapted to execute programmed instructions and selectively reconfigure the processing function of the reconfigurable processor unit in response to one of the programmed instructions. Such a configuration can be used to implement a method of efficiently processing data in an IMD.

Abstract: Techniques are provided for estimating left atrial pressure (LAP) or other cardiac performance parameters based on measured conduction delays. In particular, LAP is estimated based interventricular conduction delays. Predetermined conversion factors stored within the device are used to convert the various the conduction delays into LAP values or other appropriate cardiac performance parameters. The conversion factors may be, for example, slope and baseline values derived during an initial calibration procedure performed by an external system, such as an external programmer. In some examples, the slope and baseline values may be periodically re-calibrated by the implantable device itself. Techniques are also described for adaptively adjusting pacing parameters based on estimated LAP or other cardiac performance parameters. Still further, techniques are described for estimating conduction delays based on impedance or admittance values and for tracking heart failure therefrom.

Abstract: A non-implanted system receives, from an implantable cardiac device implanted within a patient, data corresponding to detected potential episodes of tachycardia. A representation of the data corresponding to the detected potential episodes of tachycardia is displayed to a user, and the user that observes the displayed representation of the data is allowed to enter a user diagnosis for each of the detected potential episodes of tachycardia. The non-implanted system simulates how the implantable cardiac device can use its discriminators to produce device diagnoses, based on the data for the detected potential episodes of tachycardia, including how adjustments to the discriminators affect how the device diagnoses match the user diagnoses. Thereafter, the non-implanted system can reprogram the implantable cardiac device to increase a likelihood that future device diagnoses produced by the implantable cardiac device would more closely match future user diagnoses produced by the user.