Patent application number | Description | Published |
20100113964 | DETERMINING INTERCARDIAC IMPEDANCE - A system and method for determining complex intercardiac impedance to detect various cardiac functions are disclosed involving a signal generator means for providing an adjustable direct current signal, a modulator for modulating the adjustable direct current signal to produce a modulated signal, at least one electrode for propagating the modulated signal across a myocardium, at least one sensor for detecting an outputted modulated signal from the myocardium, and at least one circuit to reduce the influence of process noise (aggressors) in the outputted modulated signal. The at least one circuit comprises an amplifier, a demodulator, and an integrator. The amplitude and phase of the final outputted modulated signal indicate the complex impedance of the myocardium. Changes in the complex impedance patterns of the myocardium provide indication of reduced oxygen and blood flow to the myocardium. The apparatus can be employed in implantable devices, including cardiac pacemakers and implantable cardioverter defibrillators. | 05-06-2010 |
20100114223 | DETERMINING INTERCARDIAC IMPEDANCE - A system and method for determining complex intercardiac impedance to detect various cardiac functions are disclosed involving a signal generator means for providing an adjustable direct current signal, a modulator for modulating the adjustable direct current signal to produce a modulated signal, at least one electrode for propagating the modulated signal across a myocardium, at least one sensor for detecting an outputted modulated signal from the myocardium, and at least one circuit to reduce the influence of process noise (aggressors) in the outputted modulated signal. The at least one circuit comprises an amplifier, a demodulator, and an integrator. The amplitude and phase of the final outputted modulated signal indicate the complex impedance of the myocardium. Changes in the complex impedance patterns of the myocardium provide indication of reduced oxygen and blood flow to the myocardium. The apparatus can be employed in implantable devices, including cardiac pacemakers and implantable cardioverter defibrillators. | 05-06-2010 |
20100198309 | ISOLATION CIRCUITRY AND METHOD FOR GRADIENT FIELD SAFETY IN AN IMPLANTABLE MEDICAL DEVICE - An implantable medical device is provided for isolating an elongated medical lead from internal device circuitry in the presence of a gradient magnetic or electrical field. The device includes an isolation circuit adapted to operatively connect an internal circuit to the medical lead in a first operative state and to electrically isolate the medical lead from the internal circuit in a second operative state. | 08-05-2010 |
20110130984 | ESTIMATING REMAINING BATTERY SERVICE LIFE IN AN IMPLANTABLE MEDICAL DEVICE - Methods for estimating a remaining service life of an implantable medical device (IMD) battery are presented. In one embodiment, a characteristic discharge model of the battery is employed. Systems employing the methods may include an external device coupled to the IMD, for example, via a telemetry communications link, wherein a first portion of a computer readable medium included in the IMD is programmed to provide instructions for the measurement, or tracking, of time and the measurement of battery voltage, and a second portion of the computer readable medium included in the external device is programmed to provide instructions for carrying out the calculations when the voltage and time data is transferred via telemetry from the IMD to the external device. | 06-02-2011 |
20110270362 | ACTIVE CIRCUIT MRI/EMI PROTECTION POWERED BY INTERFERING ENERGY FOR A MEDICAL STIMULATION LEAD AND DEVICE - An implantable lead for use with a medical device (IMD) includes active circuits incorporated into the lead to reduce the creation of an induced current, or dissipate the induced current and heat created due to an induced current in the lead. The active circuits are powered by the magnetic resonant imaging energy or interfering magnetic or electrical fields. According to various embodiments, the lead and/or its components can be provided to reduce or dissipate a current and heat induced by various external magnetic or electrical fields. | 11-03-2011 |
20120101545 | IMPLANTABLE MEDICAL DEVICE IMPEDANCE MEASUREMENT MODULE FOR COMMUNICATION WITH ONE OR MORE LEAD-BORNE DEVICES - Example techniques for communicating between two medical devices are described. One medical device may be an implantable medical device. Another medical device may be a lead-borne implantable medical device. The lead-borne implantable medical device may be referred to as a satellite. The implantable medical device may measure impedance of a path including at least two electrodes, at least one of which is on the lead, using an impedance measurement module. In some example implementations of this disclosure, the implantable medical device may also use the impedance measurement module to communicate with the satellite on the lead. | 04-26-2012 |
20130165987 | FAULT TOLERANT PACING - Methods and/or devices may be configured to monitor the performance of pacing therapy and provide fault-tolerant operation to provide therapy in the event of certain failure modes occurring in the pacing delivery circuits, leads, and/or lead/tissue interfaces. Generally, the methods and/or devices may provide fault-detection, fault-recovery and fault-handling to, e.g., handle potential faults. | 06-27-2013 |