Dochan E Kwak

US Patent:

42908850, Sep 22, 1981

Filed:

Mar 2, 1979

Appl. No.:

6/016890

Inventors:

Dochan Kwak - San Jose CA

International Classification:

C02F 316
B28B 126

US Classification:

210197

Abstract:

An efficient apparatus related in general to introducing gas into a body of liquid and more particularly to aerating wastewater contained in an activation basin by means of interacting surface agitation and gas entrainment.

US Patent:

59478926, Sep 7, 1999

Filed:

Dec 13, 1996

Appl. No.:

8/766886

Inventors:

Robert J. Benkowski - League City TX
Cetin Kiris - Palo Alto CA
Dochan Kwak - Palo Alto CA
Bernard J. Rosenbaum - Seabrook TX
James W. Bacak - Houston TX
Michael E. DeBakey - Houston TX

Assignee:

MicroMed Technology, Inc. - The Woodlands TX

International Classification:

A61M 112

US Classification:

600 16

Abstract:

A blood pump that comprises a pump housing having a blood flow path therethrough, a blood inlet, and a blood outlet; a stator mounted to the pump housing, the stator having a stator field winding for producing a stator magnetic field; a flow straightener located within the pump housing, and comprising a flow straightener hub and at least one flow straightener blade attached to the flow straightener hub; a rotor mounted within the pump housing for rotation in response to the stator magnetic field, the rotor comprising an inducer and an impeller; the inducer being located downstream of the flow straightener, and comprising an inducer hub and at least one inducer blade attached to the inducer hub; the impeller being located downstream of the inducer, and comprising an impeller hub and at least one impeller blade attached to the impeller hub; and preferably also comprising a diffuser downstream of the impeller, the diffuser comprising a diffuser hub and at least one diffuser blade. Blood flow stagnation and clot formation within the pump are minimized by, among other things, providing the inducer hub with a diameter greater than the diameter of the flow straightener hub; by optimizing the axial spacing between the flow straightener hub and the inducer hub, and between the impeller hub and the diffuser hub; by optimizing the inlet angle of the diffuser blades; and by providing fillets or curved transitions between the upstream end of the inducer hub and the shaft mounted therein, and between the impeller hub and the shaft mounted therein.