Abstract: Implantable leads incorporating accelerometer-based cardiac wall motion sensors, and a method of fabricating such leads, are provided. The cardiac wall motion sensors transduce accelerations of cardiac tissue to provide electrical signals indicative of cardiac wall motion to an implantable cardiac stimulating device. The implantable cardiac stimulating device may use the electrical signals indicative of cardiac wall motion to detect and discriminate among potentially malignant cardiac arrhythmias. In response to a detected abnormal cardiac rhythm, the cardiac stimulating device may deliver therapeutic electrical stimulation to selected regions of cardiac tissue.

Abstract: An atrial defibrillator applies cardioverting electrical energy to the atria of a human heart in need of cardioversion. The defibrillator includes an electrode pair and a sense amplifier associated with the atria of the heart for sensing electrical activity of the heart during a plurality of cardiac cycles to provide a cardiac signal. A detector is responsive to the cardiac signal for detecting cardiac events. During each cardiac cycle of the plurality of cardiac cycles, a time for counting is established wherein each time for counting has a total duration less than the duration of its corresponding cardiac cycle. A counter counts the cardiac events detected by the detector during the time for counting of the plurality of cardiac cycles to provide a cardiac event count. A comparator compares the cardiac event count to a predetermined cardiac event count.

Abstract: During sampling, a finite impulse response (FIR) filter separates a composite signal into two components, non-cardiac physiological phenomena and cardiac artifacts. The length of the filter window dynamically varies to produce an output signal in which the cardiac frequency and any associated harmonics are suppressed. The FIR filter is applied to the patient signal and lags the patient signal by at least one interval between triggering events. When the present interval between triggering events passes by the filter window, the window length is gradually adjusted to have the same length as the next period such that the triggering events are synchronized with the endpoints of the filter window at the start of each interval. The difference between the present interval and the next interval is evenly distributed or subtracted across the filter window between synchronizations.

Abstract: A method for producing a detecting phosphorescent emission from a body portion comprising the following steps: inserting phosphorescent material into the body portion; inserting a needle into said body portion, said needle encasing a light guide for propagating a light signal therethrough, said light signal exciting said phosphorescent material within said body portion so as to produce a phosphorescent emission having a radius of visibility; and collecting the phosphorescent emission using a collector placed proximate to the surface of the body portion. The present invention also encompasses apparatus for inserting an excitation light into a tissue sample comprising: a needle having a light guide extending axially within the needle, the light guide being configured to transmit an excitation light into the body portion, so as to a phosphorescent carrier medium within the tissue sample.

Abstract: Apparatus for multi-channel transverse epidural spinal cord stimulation uses a multi-channel pulse generator driving a plurality of electrodes mounted near the distal end of a lead. These electrodes are mounted in one or more lines, generally perpendicular to the lead axis, and have a planar surface along one surface of the lead. The lead is implanted adjacent to spinal cord dura mater with the electrodes transverse and facing the spinal cord. Pulses generated by the pulse generator for each channel are normally simultaneous, of equal amplitude and of equal duration, however the pulse generator is arranged such that pulses for each channel can selectably alternate in time, can selectably be of unequal amplitude, or both. The changes in pulse timing and magnitude permit shifting the electrical stimulation field and the resulting paresthesia pattern after installation to accommodate improper lead placement or postoperative dislocation and to minimize unwanted motor responses.

Abstract: A heart stimulator emits stimulation pulses to a heart, and has a regulator unit for regulating a variable function in the heart stimulator, a measurement device for measuring the return flow of blood to the heart, and a control device for controlling the regulation of the function by the regulator unit on the basis of changes in the return flow of blood. The regulator unit may be a pulse generator which generates and emits the stimulation pulses at a variable interval, the heart stimulator then becoming rate-adaptive and optimizing cardiac output. In this manner, heart rate is regulated on the basis of a variable directly related to the body's oxygenation needs.

Abstract: A device and method for assisting ventricular output in a human heart by compressing the heart. In the method, an electrocardiogram is generated as a function of the electrical activity of the heart, and an electromagnetic field is generated as a function of the electrocardiogram. A magnetic mat is moved towards the vertebral body to compress the heart therebetween in response to application of the electromagnetic field thereto. The device includes a transducer and control circuit to regulate the compressive force applied to the heart.

Abstract: An implantable medical device including a piezoelectric accelerometer activity sensor. The activity sensor includes a thin film piezoelectric cell within a frame structure. A mass imposes a load based upon acceleration to apply lateral or transverse forces which cause the generation of an electrical potential within the piezoelectric cell, which can be used by a rate control algorithm within the device to control operation of the device.

Abstract: A body implantable electrode with rate controlled drug delivery is disclosed. A body implantable lead is provided for the delivery of stimulation energy to a desired body site includes a drug dispenser carried by the lead which retains a drug to be dispensed at least adjacent the desired body stimulation site. The drug may be one which is intended to counter thrombus formation, fibrosis, inflammation or arrhythmias, for example. The drug may be in liquid or powder form retained in a reservoir carried by the lead. The reservoir is formed as a pump which controls dispensing of the drug using a fluid drawing agent such as a salt.

Abstract: Implantable leads incorporating accelerometer-based cardiac wall motion sensors, and a method of fabricating such leads, are provided. The cardiac wall motion sensors transduce accelerations of cardiac tissue to provide electrical signals indicative of cardiac wall motion to an implantable cardiac stimulating device. The implantable cardiac stimulating device may use the electrical signals indicative of cardiac wall motion to detect and discriminate among potentially malignant cardiac arrhythmias. In response to a detected abnormal cardiac rhythm, the cardiac stimulating device may deliver therapeutic electrical stimulation to selected regions of cardiac tissue.

Abstract: Improvement in pacemakers for a quick and safe replacement thereof without interrupting the electric stimulation of the patient's heart from the outside, wherein the contact pin of the electro-de-catheter inserted in the pacemaker is accessible from the outside, and related tool to be utilized therewith by which tool the contact pin can be pushed out of the pacemaker; the tool is provided with contact means to the electrode catheter which means make it possible the uninterrupted electric stimulation of the heart during the whole replacement operation of the pacemaker.

Abstract: Systems and methods examine heart tissue morphology using three or more spaced apart electrodes, at least two of which are located within the heart in contact with endocardial tissue. The systems and methods transmit electrical current through a region of heart tissue lying between selected pairs of the electrodes, at least one of the electrodes in each pair being located within the heart. The systems and methods derive the electrical characteristic of tissue lying between the electrode pairs based, at least in part, upon sensing tissue impedances. The systems and methods arrange the derived tissue electrical characteristics into groups of equal electrical characteristics. The systems and methods display the groups of equal electrical characteristics in spatial relation to the location of the examined tissue regions. The systems and methods make possible the use of multiple endocardial electrodes for taking multiple measurements of the electrical characteristics of heart tissue.

Abstract: Systems and methods examine heart tissue morphology by locating electrodes in contact with a region of heart tissue to sense the timing of a local depolarization events. From this, the systems and methods derive the propagation velocities of the depolarization events and create an output that displays the derived propagation velocities in spatial relation to sensing electrode. The systems and methods can arrange the derived propagation velocities into groups of equal propagation velocities and generate in three dimensions an output of the groups of equal propagation velocities in spatial relation to the location of the sensing electrodes. The iso-conduction display more rapidly identifies the regions of slow conduction which are candidate ablation sites, than an iso-chronal or iso-delay display.

Abstract: An atrial defibrillator and method provides cardioverting electrical energy to the atria of a human heart after timing successive R to R intervals. A detector detects ventricular activations of the heart and a timer times intervals between immediately successive ventricular activations. A cardiovertor applies cardioverting electrical energy to the atria of the heart when a second time interval between a third ventricular activation and a second ventricular activation immediately preceding the third ventricular activation satisfies a predetermined criteria with respect to a first time interval between the second ventricular activation and a first ventricular activation immediately preceding the second ventricular activation.

Abstract: Systems and methods examine heart tissue morphology using three or more spaced apart electrodes, at least two of which are located within the heart in contact with endocardial tissue. The systems and methods transmit electrical current through a region of heart tissue lying between selected pairs of the electrodes, at least one of the electrodes in each pair being located within the heart. The systems and methods derive the electrical characteristic of tissue lying between the electrode pairs based, at least in part, upon sensing tissue impedances. The systems and methods also sense the timing of local depolarization events in the tissue in which impedance is sensed and derive therefrom the propagation velocities of the sensed depolarization events. The systems and methods match the derived tissue electrical characteristics with the derived propagation velocities in spatial relation to the electrodes to characterize the morphology of the contacted heart tissue.

Abstract: A device capable of recording a bioelectrical signal under the normal living conditions of a living body is arranged so that an extremely real record can be obtained not only during a walk, a meal or a sleep of the living body but also even during bathing. A base member having flexibility which permits it to follow the motion of the living body is provided with electrodes for picking up electrical signals of the living body and a recording element for recording the picked-up electrical signals. If the base member is stuck on the living body, the electrodes pick up the electrical signals of the living body and the picked-up electrical signals are recorded in the recording element. When the base member is stuck on the living body, the base member watertightly covers the electrodes. Accordingly, even if the living body is surrounded by water, the electrodes can pick up the electrical signals of the living body without touching the water.

Abstract: A balloon for an inter aortic balloon pump having an elongate tapered section extending from a proximal end of minimal diameter and progressively increasing in diameter toward the distal end. The tapered section is of greater wall thickness with the wall thickness becoming progressively thinner toward the distal end.

Abstract: A temporarily implantable electrode device, intended for sensing electrical signals from living tissue, has an insulating sheath of resorbable material, and at least one non-toxic, liquid conductor contained inside the insulating sheath in order to form an electrical conductor which, via an electrode adapted for interaction with living tissue can sense and carry electrical signals from living tissue to a medical apparatus connected to the electrode device. The resorbable material ultimately dissolves completely into the body of the subject in whom the electrode device was temporarily implanted, and the non-toxic, liquid conductor simultaneously mixes with other fluids, making explantation of the electrode device unnecessary.

Abstract: In a method and apparatus for processing ECG signals for the purpose of detecting low-amplitude signal structures hidden in noise in the ECG signal, the ECG signals, number of cardiac cycles are analog-to-digital converted, and QRS complexes in the converted signals are detected. The signals from at least two cardiac cycles are cross-correlated, and the correlation between these signals in time intervals which comprise at least the time intervals of the two samples is determined. An output quantity representing the degree of correlation is thus obtained, the magnitude of this quantity designating the amplitude of the signal structure in question. This magnitude can then be analyzed to determine if, and where in the signal, the signal structure arises.

Abstract: A pacemaker lead includes a spiral electrical conductor lead surrounded by an insulating material sheath. One end of the lead is coupled to a connection head for removable connection to a pacemaker. The other end of the lead is connected to a stimulation device. Between the ends, the lead has a sealed access structure housing an auxiliary electrical connection for electrically coupling an external stimulation source or other circuit to the conductor lead by movement across the access structure.