Tc1 LLC

Triada, Ltd.

Thoratec Corporation

Tao Zhang

Masamichi Yanai

Shunzhou Yu

K R Raghavan

Joseph M Bugajski

Jeffrey G Houdek

A blood pump system includes a pump housing and an impeller for rotating in a pump chamber within the housing. The impeller has a first side and a second side opposite the first side. The system includes a stator having drive coils for applying a torque to the impeller and at least one bearing mechanism for suspending the impeller within the pump chamber. The system includes a position control mechanism for moving the impeller in an axial direction within the pump chamber to adjust a size of a first gap and a size of a second gap, thereby controlling a washout rate at each of the first gap and the second gap. The first gap is defined by a distance between the first side and the housing and the second gap is defined by a distance between the second side and the pump housing.

Alternating pump gaps

A implantable pump system comprises an implantable pump motor and an external unit. An inverter comprises respective phases couple to the motor via a cable with redundant conductors for each phase. A controller receives power measurements for all the redundant conductors, which are combined and compared in order to detect failures in the non-redundant components within the motor and windings.

Motor fault monitor for implantable blood pump

A centrifugal pump system for a cardiac assist device employs a disc-shaped impeller having an outer circumference adapted to be rotatably driven in a pumping direction. A pump housing has a pumping chamber receiving the impeller, wherein the pumping chamber defines an outlet volute having a separation edge spaced from the outer circumference to provide a limited backflow path coinciding with the pumping direction. A motor drives the impeller in response to a voltage provided to the motor. A current sensor measures current flow within the motor in response to the voltage. A controller estimates a pump flow rate in response to a predetermined relation between the measured current and the pump flow rate, wherein the predetermined relation includes a positive slope from a predetermined backflow rate to a zero pump flow rate.

Backflow detection for centrifugal blood pump

A pattern recognition method applicable to unique associated pattern recognition in a structured information system or structured database is presented. The process may be used to find patterns in a column which are associated with unique data values in another column, or to find the number of unique values in the second column which are paired with the same associated pattern in the first column. The technique is easily extended to more general cases in which both the condition field and the associated pattern field may be two groups of fields.

Multi-dimensional pattern analysis

A virtual structured information system or a virtual database is developed and presented in the framework of an information theory for multiple source information systems such as databases. A virtual tree structure is built from virtual nodes in main memory which contain no raw data. The virtual nodes and virtual trees provide general non-data virtual structure, like cross-table nodes, for systematic information manipulations such as on-line analytical processing in a structured information system.

Virtual structured information system

By placing a low cardinality node or a leaf in a lower level, and a high cardinality node or a leaf at a higher level, an optimal memory structure is automatically generated which yields the best compression within N-gram technology. After making an initial list of parallel streams or fields, the streams are ordered in accordance with increasing cardinality. Adjacent streams (fields), or nodes, are paired, and the children of the resulting node are eliminated from the list, while a new parent node is added to the list. The resulting new list is re-arranged from right to left as a function of increasing cardinality, and the pairing steps are repeated until a single root node is remains for the final memory structure.

Growing community of inventors

Ann Arbor, MI, United States of America

Tao Zhang