Abstract: A cardiac rhythm management system selects an atrioventricular (A-V) delay based on a time-interval between an atrial depolarization and mitral valve closure (MVC). For several different A-V delays, the system measures time intervals between atrial depolarizations (i.e., sensed or paced P-waves) and accelerometer-detected MVCs. Based on this information, the system selects a particular A-V delay for improving cardiac output during subsequent delivery of cardiac rhythm management therapy.

Abstract: A system is described which has a battery, a device which is powered by the battery in an episodic manner, and a charge storage capacitor. The system has attached to the charge storage capacitor a device or devices capable of: reading the rate of charge storage; or measuring both time and charge stored or added to the charge storage capacitor so that a rate of charge storage may be calculated. The estimated replacement time for the battery, particularly for a lithium battery in a pacing device, is easily estimated. Also described herein is a process for estimating a level of energy depletion in the system.

Abstract: A method and kit for the installation of a probe, implantable in the coronary sinus network for stimulation of a cardiac cavity. The kit includes: a) a guiding catheter (14), having an internal lumen open at its two extremities and able to receive the probe (10) along its length; and b) an extension (22) comprising at its distal extremity a connector (24) engaging a monodiameter connector (20) at the proximal extremity of the probe (10). The external diameter of the connector (24) is the external diameter of the remainder of the extension (22). The external surface of the extension (22) is a surface having a low coefficient of friction as compared to the interior surface of the lumen of the guiding-catheter (14), and the external diameter is smaller than the interior diameter of the lumen of the guiding-catheter, so as to allow the guiding catheter to slide over and along the entire length of the extension, without a concomitant axial displacement of the probe.

Abstract: An implantable cardiac stimulation device, such as a pacemaker, defibrillator and/or cardioverter, and an associated method that provide cardiac stimulation to at least two ventricular stimulation sites, within a single ventricle or across two ventricles. A high intrinsic atrial rate triggers a retrograde conduction detection routine when a high ventricular stimulation rate is sustained for a predetermined number of cycles during an atrial sensing mode. This routine interrupts concurrent stimulation, and alternates the stimulation output to the different ventricular sites.

Abstract: A “leads-off indicator” for an ECG apparatus for indicating that one or more of a plurality of ECG electrodes is not properly affixed to a patient and that that obviates the need for a conventional high frequency drive signal, but instead, employs common mode input noise as a drive signal to a reference electrode such that if one of the electrodes defining an ECG vector is not properly affixed, an increase in the ambient noise on an ECG vector associated with the detached electrode occurs as a detectable event. A first algorithm is used to identify whether or not the reference electrode itself is properly affixed to the patient's right leg and, if so, the common mode signal presented to the remaining limb electrodes becomes unbalanced should one of the limb electrodes not be properly connected to the patient. An impedance balancing circuit is provided for developing signals allowing identification of a lose electrode when the ECG system does not utilize a right leg electrode as a reference.

Abstract: A steerable catheter includes an elongate cannula having a proximal end and a distal end. A blood characteristic sensor, such as an oxygen sensor, is connected to the cannula and disposed to sense percent oxygen saturation of blood at the distal end of the cannula. The blood oxygen sensor generates a signal indicative of percent oxygen saturation. An oximetry display is responsive to the signal and capable of displaying sensed percent oxygen saturation in a form understandable by an operator. A steering mechanism is operably connected to the cannula and is selectively operable by an operator to deflect the distal end of the cannula. A method of locating the coronary sinus of a heart involves endovascularly introducing a catheter into the right atrium, sensing percent oxygen saturation at the distal end of the catheter, and steering the catheter toward a region of lowest percent oxygen saturation.

Abstract: An implantable medical device, such as a cardiac stimulator, has a noise cancelling circuit which cancels noise signals relating to body movements which originate outside of the heart, and which are sensed between a noise sensing electrode located outside of the heart and the indifferent electrode of the stimulator housing. The noise cancelling circuit cancels these noise signals from the electrical signals which originate within the heart and which are sensed between the tip electrode of a stimulator lead and the indifferent electrode of the stimulator housing.

Abstract: A flexible, thin implantable electrode lead can maintain a desired portion of a lead body (14) in a desired shape conforming to a body portion. The lead body (14) includes a conductor coil (30) obtained by helically winding at least one insulation-coated electrical conduction conductor wire, an insulating sheath (32) made of an electrically insulating resin material and covering the outer surface of the conductor coil, and a flexible reinforcing tube (40) formed to deform into a desired shape in the cavity of the conductor coil.

Abstract: A system and method for receiving telemetry data from implantable medical devices such as cardiac pacemakers with improved noise immunity is disclosed. Ambient noise levels and signal strength are monitored and used to adaptively adjust the detection sensitivity of the receiver. Filtering of the received signal is performed to remove both broadband and narrowband noise. Removal of narrowband noise is accomplished with notch filters that are dynamically adjusted in accordance with a detected noise spectrum.

Abstract: A low pass filter especially adapted for use with ECG equipment designed to negate any noise energy that may be superimposed upon the ECG signal itself. A plurality of low-pass FIR filter stages are connected in tandem between a signal input point and a signal output point where each of the stages has a distinct cut-off frequency characteristic. A device is provided for selectively turning ones of the plurality of stages on or off.

Abstract: A system for assisting the failing ventricle, which utilizes a single blood displacement chamber and a single cannula. The cannula is inserted into the failing ventricle cavity and is connected to a blood displacement actuator. The device produces blood displacement at a critical time for a critical duration and with blood flow time course such that it improves the systolic function of the heart: augments the cardiac output and increases the generated pressure. The device also improves the diastolic function by increasing the ventricle compliance and imposing rapid relaxation of the ventricle wall. The device provides additional external work without deteriorating the mechanical function of the failing ventricular, moreover it decreases the energy consumption of the failing heart and improves the coronary perfusion. Consequently, the device improves the balance between the energy supply (coronary perfusion) to the ventricle wall and the mechanical demands, and allows recovery of the failing heart.

Abstract: An alternative treatment of a nonsurgically treatable intracranial occlusion using twenty minute duration sessions of exposure to radio-frequency pulsed high-peak power electromagnetic energy until there is no longer any manifesting of conditions each or combination of episodic dizzy spells and sudden hemiplegia.