Medtronic, Inc.

Lambert Muhlenberg

Chester L Struble

Pierre Andre Grandjean

Keon J Weijand

Pierre-endro Grandjean

An medical electrical lead in embodiments of the teachings may include one or more of the following features: (a) a lead body having a proximal end and a distal end, (b) a conductor traversing from the proximal end to the distal end, (c) an electrode disposed at the distal end of the lead body and electrically coupled to the conductor adapted to electrically stimulate a heart, (d) occlusion fabric disposed at the distal end of the lead body and supported by the electrode in a shape adapted to cover holes in the heart, and (f) a second electrode adapted to provide bipolar electrical stimulation of the heart.

Trans-septal/trans-myocardial ventricular pacing lead

A pacemaker provides multi-chamber pacing with a pacing interval that can be programmed and adapted in response to cardiac output measurements for a given patient. In a typical embodiment, the pacemaker may provide pacing stimuli to both ventricles of a heart. In addition, the invention may include a measurement device that incorporates first and second blood oxygen saturation sensors for deployment in the left and right ventricle. The oxygen saturation sensors provide a differential measurement that can be used to calculate cardiac output in accordance with the Fick method. The oxygen saturation sensors may be carried by a common trans-septal lead that positions one of the sensors proximate the right ventricle and the other sensor proximate the left ventricle. Alternatively, the oxygen saturation sensors may be deployed via separate leads. Whether single or dual leads are used to carry the oxygen saturation sensors, a respective lead may optionally carry electrodes for sensing, pacing, or both.

Cardiac output measurement using dual oxygen sensors in right and left ventricles

A plurality of sensors are disposed in and around the heart of a patient to collect data such as various electrical parameters, pressure parameters and temperature parameters. The data collected via the sensors may be organized and stored according to cardiac rhythm type. The organization of data according to cardiac rhythm type allows the patient's physician to be better able to monitor how the various parameters are related to the various cardiac rhythm types. In a typical embodiment, one or more of the sensors may be deployed on a single lead implanted in the heart.

Organizing data according to cardiac rhythm type

Techniques are described for estimating a rate of blood flow from a heart, such as a stroke volume or a cardiac output, as a function of a pressure in the heart. A pressure monitor may measure pressure values, and identify the times at which pressure values and valve opening and closing occur. The pressure monitor may estimate a velocity-time function as a function of the measured pressures and identified times, and may calculate a velocity-time integral by integrating the velocity-time function. The pressure monitor may also calculate an estimated velocity-time integral directly as a function of the measured pressures and the identified times. The pressure monitor may calculate the stroke volume or cardiac output using the velocity-time integral. The pressure monitor may control a delivery of therapy by an implantable medical device as a function of the stroke volume or cardiac output.

Estimation of stroke volume cardiac output using an intracardiac pressure sensor

In a system that includes a ventricular pacemaker, the system adjusts an atrioventricular delay to synchronize the onset of isovolumetric contraction with the completion of ventricular filling. The system adjusts the atrioventricular delay as a function of electrical and pressure data from the heart. The system further adjusts the atrioventricular delay as a function of measurements of the time interval between a cardiac occurrence such as a ventricular pace and the completion of ventricular filling. The system may also adjust the atrioventricular delay as a function of the heart rate.

Atrioventricular delay adjustment

A system and method of non-linear sampling of an analog signal, and for data compression, to provide overall compressed digital representative of analog signal such as a physiological signal obtained in a battery powered device such as an implantable pacemaker. Non-linear sampling is provided by generating a time varying threshold signal against which the analog signal is compared every clock sample, with the sample being skipped if the input analog signal does not exceed the threshold signal. The threshold signal can be either analog or a plurality of discrete levels, enabling up to a predetermined maximum number of samples to be skipped. The non-linearly sampled data is further compressed, using lossless techniques for compressing both the amplitude data and the data representative of skipped samples, to provide data for decompression. In a specific pacemaker embodiment, the data compression system recognizing a marker channel event, and includes data representative of the time and type of marker channel event.

System and method of data compression and non-linear sampling for

A system and method for more efficient data compression is provided, being particularly applicable to use in battery powered devices where there is a premium on minimizing the steps required and the amount of memory that must be dedicated to the task. The invention utilizes the technique of determining a delta or difference between each successive sample of the signal and the prior sample; examining the delta signals for a block comprising a predetermined number of such delta signals; determining the largest absolute delta value; determining the number of bits required to store such largest delta; and then storing both the determined number of bits and each delta value which is encoded with such determined number of bits. The block size is chosen to correspond to the type of signals being processed, and for typical medical applications is selected as a size within the range of 5-12 samples. The compressed data can be efficiently transmitted, such as from an implanted medical device to an external receiver, and decompressed by algebraically adding each delta to the value of the prior sample to recreate the respective samples and the signal.

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Landgraaf, Netherlands

Lambert Muhlenberg