Medtronic, Inc.

Craig D Petersen

Brian J Steffens

Roger A Naidyhorski

Daniel Cheek

Charlene X Yuan

Trevor Huang

Walter Carpenter

Tessy Kanayinkal

Lawrence Erickson

Kartik Radhakrishnan

A pump drive for an extracorporeal blood pumping system including an adjustable drive magnet. The pump drive may be coupled to a blood pump which includes a pump impeller. The pump drive may include a stepper motor for dynamically adjusting the position of the drive magnet. The position of the drive magnet may be varied to vary the distance between the drive magnet and an impeller magnet of the pump impeller. Adjusting the position of the drive magnet may include dynamically adjusting the drive magnet and may include axially moving the drive magnet to thereby vary a magnetic attraction force between the drive magnet and the impeller magnet which may thereby minimize forces acting on one or more bearings of a pump impeller.

Reducing centrifugal pump bearing wear through dynamic magnetic coupling

Activated clotting time (ACT) tests detect blood clotting time based on the viscosity changes of a test sample, using a ferromagnetic washer lifted to the top of a test chamber and then dropped from the top via gravity; a drop time greater than a preset threshold value indicates clotting of the test sample. Blood samples which have high levels of heparin usually produce very weak clots that may easily be destroyed by the lifting movement of the washer. But if the clot threshold is set low to detect the weak clots, false detections occur during early testing cycles when activators are not fully suspended during the mixing cycle. Improved algorithms for lifting the washer and adjusting over time enable accurate detection of weak clots.

Clot protection and detection algorithm for activated clotting time testing

A roller pump including a drive shaft, a motor, a roller head assembly, a stator housing, and an occlusion adjustment assembly. The drive shaft is coupled to the motor. The roller head assembly includes a hub, a slide body, and a roller. The hub is mounted to the drive shaft, and maintains the slide body and the roller. The stator housing forms a raceway receiving surface. The occlusion adjustment assembly includes an actuator knob, an actuating structure, and a ground shaft. The actuating structure interfaces with the slide body, and thus the roller, with rotation of the knob. The ground shaft supports the knob and is rotationally isolated from the drive shaft. A user and optionally a control system can adjust occlusion while the pump continuously delivers a fluid medium.

Roller pump with dynamic occlusion adjustment

Multi-zone falling washer blood clot detection

Growing community of inventors

Minneapolis, MN, United States of America

Craig D Petersen