Abstract: An implantable endocardial defibrillation lead having an elongated lead body with multiple lumens therein. Windows, cut through the lead body, provide access to selected ones of the lumens at selected locations along the lead body. In addition, a method and an apparatus for forming windows in a multilumen lead body are disclosed. A ferromagnetic stylet is inserted into a selected lumen. The lead body is oriented in a jig by application of an electromagnetic field. A grinder or punch cuts a window into the selected lumen.

Abstract: An apparatus for contemporaneously treating a sequence of treatment sites in an internal organ and creating a viewable map of the treated sites includes a first catheter having a proximal end and a distal end for insertion through a body passage to tissue needing treatment. A needle assembly is attached to the distal end of the first catheter to permit injection of fluid into treatments sites of the tissue. A fluid injection assembly is connected to the proximal end of the first catheter and containing predetermined amounts of radiographic contrast agent and treatment agent for injection into the various treatment sites. A radiographic visualizing apparatus is aimed at the treatment sites, including a display screen for displaying the extent of migration of radiographic contrast agent around each treatment site after injection, so that a radiographic marking appears on the display screen for a predetermined amount of time after each injection, showing which treatment sites have been treated.

Abstract: Apparatus for opening an obstructed region of a patient blood vessel comprising a catheter and guidewire. The guidewire is of sufficient length to extend from a region outside the patient to the obstructed region. The catheter acts as a guide tube supporting the guidewire for free axial and rotary movement. A power assembly is positioned outside the patient and has an output shaft joined to the guidewire. The power assembly further includes plural motors drivingly interrelated to move the output shaft to impart simultaneous axial reciprocation and rotary reciprocation to guidewire.

Abstract: Two-chamber pacemaker (100), comprising atrium sensing means (EA, 107) as well as ventricle sensing means (EV, 105) and refractory switching means (100B) for influencing the processing of output signals from the atrium sensing means for a predetermined refractory time, further comprising ventricle stimulation means (106, EV) and a stimulation control unit (100A), which effects a changeover back from a non-atrium synchronous 1:1 operating mode to an atrium-synchronous 1:1 operating mode in dependence on the signals from the atrium sensing means that are influenced by the refractory switching means.

Abstract: An implantable medical device determines activity levels and Heart Rate and from a combination of these produces a value for a heart rate activity coefficient (HRAC). This value has significant diagnostic and patient tracking value. Methods and apparatus for determining this HRAC value are described. This enables physician review of patient cardiac status. Additional physiologic data can be recorded along with the HRAC data if desired, and this too, as well as the HRAC data alone, may be reported out from the implanted device to a medical communications system for alarm purposes, titrating drugs/therapies or other monitoring tasks. Further, substitutes for heart rate measurements and activity measurements are described which can be used to augment or substitute for heart rate measurements and activity measurements.

Abstract: A stethoscope cover for preventing a stethoscope from being contaminated by and transmitting infectious organisms and other biohazards is made of an acoustically transmitting and viral, bacterial, and fluid impermeable material to protect the stethoscope without interfering with the normal function of the stethoscope. The cover includes a body having a front panel and a back panel. The front and back panels are joined to form a pouch with a closed distal end and an open proximal end. The pouch is configured and dimensioned to receive the head and the connector portion of the stethoscope. The cover also includes a first flap connected to one side of the proximal end of the pouch and a second flap connected to the other side of the proximal end of the pouch. The first and second flaps are configured and dimensioned to cover most of the first and second ear tubes, respectively.

Abstract: A diagnostic system for intracardiac electrophysiological phenomena is provided. The phenomena are inferred based on at least one of a potential obtained from a patient and a magnetic field obtained from the patient. The system comprises inferbly analyzing element for analyzing the at least one information so as to obtain a characteristic quantity associated with at least one of a magnitude and an interval of a myocardial electroaction amount of the patient; and visualizing element for displaying the characteristic quantity as a distribution image.

Abstract: Mathematical functions such as recursive autoregression models which include parameters are used for defining the heart signal and any signals disturbing the heart signal, such as polarization signals. By registering, during a predetermined time interval, the electrode signal for determining the parameters for one or more different mathematical functions, the parameters can be used on their own or in combination to determine the activity of the heart, i.e., whether the registered electrode signal corresponds to a stimulated, spontaneous or absence of heart activity.

Abstract: Method and apparatus for continuous, non-invasive determination of cardiac output which processes a sequence of non-invasive cardiography signals which are quantitatively dependent upon cardiac output within a computer system and associated neural network capable of generating a single output signal for the combined input signals, wherein the neural network applies weighting factors determined during a training phase to force the output signal to match the known value of cardiac output determined by invasive means and reports the single output signal as the determined value of cardiac output.

Abstract: A thin film capacitor for use in an implantable defibrillator. A first dielectric polymer filmlayer has a metallized film on one side thereof. A second dielectric polymer film layer has a metallized film on one side thereof. The first and second layers are overlain on each other and wound spirally with the metallized film of one layer adjacent the dielectric polymer of the other layer. The beginnings and ends of the first and second metallized films are offset from the respective beginnings and ends of the first and second polymer film layers. The dielectric layers can be tapered in increasing thickness toward the respective beginnings and ends of the layers. The dielectric layers can themselves comprise at least two layers of differing polymer materials, the preferred materials being polyvinylidene fluoride and polyester for improved energy density and self-healing properties.

Abstract: An electrical method and apparatus for stimulating cardiac cells causing contraction to force hemodynamic output during fibrillation, hemodynamically compromising tachycardia, or asystole. Forcing fields are applied to the heart to give cardiac output on an emergency basis until the arrhythmia ceases or other intervention takes place. The device is used as a stand alone external or internal device, or as a backup to an ICD, atrial defibrillator, or an anti-tachycardia pacemaker. The method and apparatus maintain some cardiac output and not necessarily defibrillation.

Abstract: A system and method for discriminating cardiac rhythms occurring in an antegrade direction from cardiac rhythms occurring in a retrograde direction. Atrial and ventricular contractions are sensed, from which atrial and ventricular cycle lengths are determined. Ventricular contractions are also analyzed to determine the occurrence of a tachycardia episode that has a one-to-one association of atrial contractions to ventricular contractions. During a tachycardia episode having a one-to-one association of atrial contractions to ventricular contractions, the atrial cycle lengths are paired with the ventricular cycle lengths, where for each of the atrial cycle lengths the atrial cycle length is paired with at least one ventricular cycle length started before the first atrial contraction of each of the atrial cycle lengths and paired with at least one ventricular cycle length started after the first atrial contraction of each of the atrial cycle lengths.

Abstract: An electrically active substance is prepared by flowing a high frequency alternating electric current through an electrolytic material, such as distilled water with NaCl dissolved therein, so as to change a physical property of the material. The alternating current is caused to flow through the electrolytic substance for preferably 4 to 8 hours. The current flow is then removed and the resulting electrically activated substance is then applied to human or animal skin to provide cosmetic/medical benefits, such as the reduction of skin wrinkles, preferably within 4 days. The substance may also be orally ingested.

Abstract: A programmable output current source for use within an implantable tissue or nerve stimulator, e.g., an implantable cochlear stimulator or spinal cord stimulator, includes parallel-connected P-FET current source sets connected between a positive voltage rail and an electrode node, and parallel-connected N-FET current source sets connected between the electrode node and a negative voltage rail. The N-FET current source sets include n N-FET current sources, where n is an integer 0, 1, 2, 3, 4, . . . , and wherein each N-FET current source, when enabled, respectively sinks a current 2nI from the electrode node to the negative rail, where I is a selectable fixed current. Similarly, the P-FET current source sets include n P-FET current sources, where n=0, 1, 2, 3, . . . n, and wherein each P-FET current source, when enabled, respectively sources a current 2nI from the positive voltage rail to the electrode node.

Abstract: A method for external treatment of dysrhythmias including fibrillation of a patient's heart utilizes an externally located control box which generates electrical waveforms including shocks of variable energy content sufficient for terminating the dysrhythmias. A lead having transvenous defibrillation electrodes is inserted through a portion of the patient's venous system to position the electrodes to produce an electric field vector through the patient's heart when an electrical shock of sufficient energy content is applied across the electrodes. The control box is electrically connected to the lead to deliver electrical shocks from the control box to the electrodes, and to deliver a representation of the patient's ECG waveform to the control box. A display screen on the control box aids in synchronously triggering the electrical shocks in response to detection of the QRS complex of the ECG waveform.

Abstract: A lead and a lead system for dispersion of a cardioversion/defibrillation electrode formed of one or more small diameter defibrillation electrodes in a heart chamber and for attaching a pace/sense electrode in contact with the heart. The small diameter defibrillation electrode or electrodes extend distally from the distal end of the lead body. If multiple electrodes are employed, they are preferably biased to spread apart when unrestrained and have a cross-section size small enough to be inserted into interstices of trabeculae in the ventricular chamber. The distal ends of the defibrillation electrodes may be free of attachment to the lead body or may be attached by a weak bond to the distal portion of the lead.

Abstract: A method for mapping surgical target site contours precisely, especially the outer contour thereof, comprises the following steps: producing a plane slice image through the surgery site in the region of the surgery target whereby the plane of the slice image is located substantially perpendicular to a a plane of symmetry of the surgery target site; assigning the images split by the plane of symmetry, more particularly by mirrowing at the plane of symmetry; and establishing the difference in the image contents between the assigned split images and processing the resulting information to determine the location of the contour of the surgery target site, especially the outer contour thereof in the plane of the slice image.

Abstract: A method of controlling the blood pressure in a patient with high blood pressure or low blood pressure utilizing a non-invasive nerve stimulation device applied to the wrist.

Abstract: An external defibrillator with an output circuit having four legs arrayed in the form of an “H” (an “H-bridge”) is disclosed. The output circuit is designed to be able to conduct a range of defibrillation pulse energies, from below 50 joules to above 200 joules. Each leg of the output circuit contains a solid-state switch. By selectively switching on pairs of switches in the H-bridge, a biphasic defibrillation pulse may be applied to a patient. The switches in three of the legs of the H-bridge output circuit are preferably silicon controlled rectifiers (SCRs). Gate drive circuits are coupled to the SCRs to bias the SCRs with a voltage that allows the SCRs to remain turned-on even when conducting low current. The switch in the fourth leg is preferably a pair of insulated gate bipolar transistors (IGBTs) coupled in series. A gate drive circuit is coupled to the gate of the IGBTs to provide a slow turn-on and a fast turn-off of the IGBTs.

Abstract: There is disclosed a system for determining a pacing energy stimulation threshold of a heart chamber for use in a cardiac pacemaker for applying to the chamber of the heart pacing electrical pulses of sufficient energy so as to exceed a pacing energy stimulation threshold. The system includes a pulse generator which repeatedly applies pacing electrical pulse pairs to the chamber. Each electrical pulse pair includes a first pulse and a second pulse. The first pulse precedes the second pulse and is of lesser energy than the second pulse. The first and second pulses evoke a first and second response respectively of the chamber. A subtractor subtracts the second response from the first response for each pulse pair to provide a series of capture values. The stimulation threshold is selected when the capture values change sign. Also disclosed is a method carried out by the disclosed system.