Medtronic, Inc.

Opti Medical Systems

Narayanan Ramamurthy

Christopher M Hobot

Daniel Cheek

Douglas Dean Nippoldt

Qingshan (Sam) Ye

Kelvin Bonnema

Wei Qin

Vitally G Sitko

Randy Meyer

Chao Lin

Charlene X Yuan

Huarui He

Mark A Thompson

Vitaly G Sitko

Colleen Lutz

Jyotsna Ghai

Daniel S Cheek

Quingshan Ye

Methods and devices for point of care determination of heparin concentration in blood are described. Cartridges including protamine ion sensitive electrodes (ISEs) and reference electrodes and systems for automatically determining heparin concentration in the cartridges are provided. Some systems add blood to a protamine bolus sufficient to bind all heparin, leaving excess protamine. The excess protamine concentration can be determined by measuring the initial slope of the electrode potential rate of change, and comparing the slope to known protamine concentration slope values In some cartridges, an oscillating pressure source moves the blood-protamine mixture back and forth across the protamine ISE. Some systems also use a second blood sample having the heparin removed or degraded to create a blank reference sample. Protamine ISEs can include polyurethane polymer, DNNS ionophore, and NPOE plasticizer. The polyurethane may include hard segments and soft segments, where both hard and soft segments may include cyclic and straight chain aliphatic moieties having essentially no ester or ether groups. Some hard segments may include methylene diphenyl groups. Some reference electrodes have the same polymer, plasticizer, and ionophore as the measurement electrode, but with a different concentration of ionophore.

Point of care heparin determination system

The invention is directed to optical sensors for measuring clinically relevant analytes, their methods of manufacture, and their various uses. In an effort to develop a dry calibration method for the optical sensors of the invention it is discovered that water content inside or in the immediate vicinity of a such a sensor can have a major impact on fluorescence intensity (i.e., a sensor's response in the dry state). Thus, one of the objectives of the invention is the elimination of the bias of sensor responses measured at different humidity environments.

Spreading layer and humidity control layer for enhancing sensor performance

A method and kit for testing a multi-channel blood-testing cartridge. In particular, blood-testing cartridges are tested with plasma samples with clotting times measured to indicate whether a batch of cartridges is suitable for testing the blood of a patient.

Method and kit for testing a multi-channel blood assay cartridge

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Alpharetta, GA, United States of America

Narayanan Ramamurthy