Armando Tr Federico

US Patent:

39851230, Oct 12, 1976

Filed:

Jul 17, 1975

Appl. No.:

5/596907

Inventors:

George A. Herzlinger - Belmont MA
Armando Federico - Needham MA
Arthur R. Kantrowitz - Cambridge MA

Assignee:

Avco Everett Research Laboratory, Inc. - Everett MA

International Classification:

A61B 502

US Classification:

128 205F

Abstract:

A cardiac output monitor. The monitor receives signals representing radial arterial pressure, balloon pressure, balloon drive and balloon volume from an intra-aortic balloon pumping system. These signals are processed to define balloon depletion pressure (P. sub. 1), ventricle ejection pressure (P. sub. 2), balloon volume (BV) and heart rate (HR). The monitor displays the cardiac output according to Cardiac output = (P. sub. 2 /P. sub. 1) (BV) (HR) the monitor also indicates certain improper pumping system operations and can provide a continuous display.

US Patent:

40461378, Sep 6, 1977

Filed:

Aug 11, 1976

Appl. No.:

5/713546

Inventors:

Richard W. Curless - Nabnasset MA
Armando Federico - Needham MA

Assignee:

Avco Corporation - Greenwich CT

International Classification:

A61M 103
F04B 910

US Classification:

128 1D

Abstract:

A solenoid operated drive system or actuating unit for driving blood pumps such as intra-arterial "balloon" pumps, implantable pulsatile pumps, external pumps and the like, wherein a shaft attached to the movable end of a bellows is caused to move back and forth by a pair of oppositely disposed solenoids. The extent of the excursion of the shaft and hence the movable end of the bellows is variably controlled by a first stopper fixedly attached to the frame and a second stopper fixedly attached to a carriage which is adjustably carried within the frame. The solenoids are alternately actuated and/or controlled by suitable control signals which are keyed to the heartbeat or R wave. At the beginning of each cycle for each solenoid and for a short time thereafter, depending on the cycle, a voltage is applied to provide maximum drive. At the end of the maximum drive portion, a reduced voltage is applied to provide a drive and/or holding force of lesser magnitude and is maintained until after the shaft has stopped moving. Thereafter, the reduced voltage is removed and/or current flow through the solenoid is prevented for a further period of time until the next cycle for this solenoid begins with the application of the high voltage.