Cook Pacemaker Corporation

Arco Medical Products Company

Cook Vascular Incorporated

Coratomic Inc.

Medical Engineering and Development Institute, Inc.

William L Johnson

Donald A Stevens

Kevin S Heggs

Neal E Fearnot

Louis B Goode

David L Purdy

Frederick J Shipko

Robert A Walters

Vernon L Speicher

Barry E Norlander

James R Zewe

Carl A Cook

Donald J Bowser

Gary W Bivins

A medical device ( ) such as a radio frequency dilator sheath for separating an encapsulated elongated structure ( ) such as an electrical cardiac lead implanted in biological tissue ( ) such as a vessel leading to or from a patient's heart. The radio frequency dilator sheath includes inner and outer coaxial dilator sheaths ( and ) with respective beveled distal ends ( and ) for mechanically loosening and separating encapsulating tissue from an implanted electric cardiac lead. The beveled distal end of the inner sheath is truncated to form a transverse face or surface ( ) that is approximately perpendicular to the longitudinal axis of the sheath. Electrical conductors ( and ) are positioned about the distal end ( ) and passage ( ) of the inner dilator sheath. When energized, the electrical conductor emits an electrical arc which electrically separates encapsulating biological tissue from the elongated electrical structure implanted therein and placed in the passage of the inner elongated dilator sheath.

Radio frequency dilator sheath

A pacemaker is disclosed with a pacing rate that is restricted within a range defined by variable upper and lower rate limits that change as a function of the patient's detected level of activity. An indication such as the nonambient temperature of blood is sensed in the right ventricle of the heart to indicate detected activity level. Other activity indications, such as blood oxygen concentration and body motion, either singly or in combination are also disclosed. A control circuit of the pacemaker varies the upper and lower rate limits according to the patient's detected level of activity. The control circuit also varies the atrial and ventricular refractory periods along with the AV delay period in response to detected activity level changes.

Pacemaker with activity-dependent rate limiting

Method and appartaus are disclosed for stimulating the heart with a pacemaker in response to a nonambient temperature of a body, which is sensed, for example, in the right ventricle of the heart. The pacemaker stimulates the heart at one of at least three different nominal rates which have been selected by the physician for the various activity levels of the patient. When the heart is stimulated at an interim rate for mild or brief exercise conditions, the activity level of the patient is sensed using a motion sensor. A control circuit terminates a predetermined time period selected for the pacemaker to stimulate at the interim rate when the sensed level is less than a predetermined activity level. The stimulation rate of the heart is controlled by the nonambient body temperature sensed in the right ventricle of the heart, but the sensed motion or activity level of the patient is used to terminate the interim time period when the sensed activity level of the patient does not correspond to the level of activity intended for the selected stimulation rate.

Temperature-controlled cardiac pacemaker responsive to body motion

A programmable digital atrio-ventricular pacer is provided whereby a single programming circuit is utilized for providing program control signals for control of separate ventricular and atrial pacing circuits. The atrial stimulus circuitry is controlled by a multiple bit control signal to cause derivation of atrial timing signals from the same clock signal as used for deriving ventricular stimulus pulses. A programmable digital multiplier is employed in combination with a counter to set the atrial escape interval independent of the timing of the ventricular stimulus pulses.

Programmable atrio-ventricular pacer

A method of making a pacemaker which includes, in a container a subassembly of, a battery nested in an electrical converter serving to produce heart-pacing pulses. This subassembly is encapsulated in a mold in rigid, polyurethane foam of low weight and capable of protecting the encapsulated components from shock. The body formed by prepotting is generally ellipsoidal and is nested snugly in one of the sections of an ellipsoidal container. Another section of the container is welded to the one section along the congruent rims. Additional potting material is injected through the boards between the sides of the encapsulated body and the adjacent walls of the container. The encapsulated body is held firmly in the container without potting material between the top and bottom and ends of the body and the container. The potting material is injected through the hole in which the electrical feedthrough is subsequently welded. Alternatively, the pacemaker is formed by enclosing the subassembly between the parts of the container, welding the sections of the container, and injecting the foam through the opening in the container through which the output conductor passes.

Pacemakers of low weight and method of making such pacemakers

Growing community of inventors

Kittanning, PA, United States of America

William L Johnson