Pacific Diabetes Technologies Inc

William Kenneth Ward

Robert S Cargill

Thomas Seidl

Gabriel Heinrich

Sheila Benware

Mark Vreeke

Joseph D Kowalski

Huan-Ping Wu

A device for delivery of an insulin or insulin analog formulation and measurement of subcutaneous glucose concentration may comprise a hollow tube, and an amperometric glucose sensor located proximal to a distal end of the hollow tube. The amperometric glucose sensor may comprise a redox mediator and an enzyme comprising glucose oxidase or glucose dehydrogenase. An applied bias potential may allow an electrode layer of the amperometric glucose sensor to undergo substantially no electropolymerization of an excipient of the insulin or insulin analog formulation during continuous operation of amperometric glucose sensor. A sensitivity of the amperometric glucose sensor to the subcutaneous glucose concentration may be maintained in presence of the insulin or insulin analog formulation.

Measurement of glucose near an insulin delivery catheter by minimizing the adverse effects of insulin preservatives: alternative ligands and redox mediator metals

A method may comprise (a) inserting an insulin delivery device subcutaneously into a body of a subject, which comprises an amperometric glucose sensor comprising an electrode layer comprising an indicating electrode and underlying a redox-catalytic layer comprising a redox mediator; (b) using said insulin delivery device to deliver an insulin formulation (e.g., comprising a phenol or cresol excipient) subcutaneously to said subject; and (c) using said amperometric glucose sensor to measure a subcutaneous glucose concentration, which comprises using said redox-catalytic layer to allow electron transfer from subcutaneous glucose to said indicating electrode sufficient to cause a response of said amperometric glucose sensor at an applied bias potential of no more than +250 millivolts, wherein (b) and (c) are performed at the same time for at least one hour, while maintaining a sensor sensitivity of at least 50% of an initial sensor sensitivity for up to one hour.

Methods and systems for insulin delivery and glucose measurement

In an aspect, the present disclosure provides a method comprising: (a) positioning an insulin delivery device on a body of a subject via a single puncture site in said body of said subject; (b) using said insulin delivery device to deliver an insulin or insulin analog formulation to said subject via said single puncture site; and (c) using a sensor of said insulin delivery device to measure a glucose concentration in said body of said subject via said single puncture site, wherein (b) and (c) are performed at substantially the same time for a time period of at least 1 hour subsequent to said positioning in (a), while maintaining a sensitivity of said sensor of at least 50% of an initial sensitivity of said sensor.

Methods and devices useful for determining the analyte concentration of a sample using output currents obtained from an input potential in the kinetic potential region of a redox mediator are disclosed. Preferably, the input potential used to generate the output currents from the kinetic potential region of the redox mediator is continually increasing with time after initiating the analysis. A method of selecting an initial input potential within the kinetic potential region of a redox mediator based on the sensitivity of an individual or batch of subcutaneously insertable test sensors also is described. A method of selecting an analysis input potential within the kinetic potential region of redox mediator based on the sensitivity of an individual subcutaneously inserted test sensor also is described where the analysis input potential is increased with insertion time.

Biosensors and methods for determining analyte concentration in the kinetic potential region of redox mediators

This disclosure teaches the concept, and method of creating, a dual use device intended for persons who take insulin. In one embodiment, the novel device is an insulin delivery cannula, the outer wall of which contains electrodes, chemical compounds and electrical interconnects that allow continuous glucose sensing and delivery of data to a remote device. Heretofore, the main problem in attempting to sense glucose at the site of insulin delivery has been the high current resulting from oxidation by the sensor of the preservatives in the insulin formulations. One means of eliminating these interferences is to poise the indicating electrode(s) of the sensor at a bias sufficiently low to avoid the signal from oxidation of the preservatives. One way of obtaining a glucose signal at a low bias is to use an osmium-ligand-polymer complex instead of conventional hydrogen peroxide sensing. Another is to use a size exclusion filter located in line with the insulin delivery tubing in order to remove the smaller phenolic preservative molecules while allowing the larger insulin molecules to pass unimpeded. These filtration concepts can also be more broadly applied, that is, the general concept of removal of unwanted drug formulation excipients from a drug delivery system.

Growing community of inventors

Portland, OR, United States of America

William Kenneth Ward