Barouh V Berkovits

44211147, Dec 20, 1983

Aug 11, 1980

6/177285

Barouh V. Berkovits - Newton Highlands MA
Ray S. McDonald - St. Paul MN

A61N 136

128419PG

Treatment of re-entry tachycardias through the use of a pacemaker which includes sequentially timed oscillators for delivering stimulating pulses to an atrium and ventricle, preferably on a demand basis, and a circuit for detecting a tachycardia condition and switching to an asynchronous mode of operation. The detector does not respond to a single extraneous or premature beat, but after a predetermined number of beats occurring above a predetermined normal beat rate the detector switches the pacemaker to an asynchronous mode. Relative variation in the phase of the asynchronous pacing and the tachycardia beats results within a short time in occurrence of a pulse in the critical time period to stop the tachycardia. The use of sequential stimulation in both chambers overcomes some of the problems in selecting the proper site for stimulation. Hysteresis is provided in the heartbeat rate detecting circuit for preventing premature discontinuance of the asynchronous mode due to masking of pulses by the refractory period of the QRS-wave amplifying circuits.

45776334, Mar 25, 1986

Mar 28, 1984

6/594606

Barouh V. Berkovits - Newton Highlands MA
Menashe B. Waxman - Toronto, CA
William J. Combs - Shoreview MN

Medtronic, Inc. - Minneapolis MN

A61N 136

128419PG

A self-adapting demand pacemaker that recognizes the tachycardia from the intrinsic signals and initiates treatment in the following manner: First, the escape interval of the demand pacemaker is shortened to be identical to the cycle length of the tachycardia, then to overdrive the tachycardia the pacemaker escape interval is continuously shortened with each subsequent beat, for a predetermined number of beats, by a small programmable decrement. Thereafter, the escape interval is restored to its original value and protects against a potential bradycardia. It has to be emphasized that the pacemaker remains in demand mode all of the time; thus stimulation in a vulnerable zone is prevented and some of the hazards that accompany overdrive pacing are reduced. An additional advantage of this treatment is that since each stimulus is delivered only a few milliseconds before the next intrinsic depolarization is expected to arrive at the site of the electrode, it facilitates capture even when the excitable interval is extremely short.

49324063, Jun 12, 1990

Sep 23, 1988

7/249046

Barouh V. Berkovits - Newton Highlands MA

Medtronic - Minneapolis MN

A61B 100

128419PG

A pacemaker which operates in an atrial synchronized modality when the sensed atrial rate is within a physiologic range and which paces at a sensor determined rate when the atrial rate is above or below the physiologic range.