University of Southern California

Christian A Gutierrez

Ellis Fan-chuin Meng

Electrochemical impedance may be used for accurate and real-time tracking and control of fluid delivery from fluid-filled chambers, such as from drug delivery devices. At least two measurement electrodes may be placed within the chamber in contact with the fluid to be sensed. Application of a small alternating current using these electrodes through the fluid/drug may allow measurement of electrochemical impedance. Volumetric changes of the compressible chamber due to movement of at least one surface within the compressible chamber (such as an actuating bellows or flexible diaphragm), may induce changes in the measured electrochemical impedance. Measuring these changes may allow for tracking of ejected liquid volumes from the compressible chamber. By taking the time-derivative of this signal, the rate of volume change can be tracked and therefore the rate of ejected fluid (flow rate) can be deduced.

Tracking and controlling fluid delivery from chamber

A pressure transducer for measuring pressure may include an all-polymer chamber that has no dimension greater than 1 mm. There may be fluid within the chamber, a gaseous bubble trapped within the fluid, and electrodes in contact with the fluid. The electrodes may enable a measurement of changes in the impedance of the fluid caused by changes in the volume of the gaseous bubble caused by changes in the pressure to be measured. The pressure transducer may be made by depositing the chamber, placing the fluid within the chamber, and generating the gaseous bubble within the fluid with electrolysis.

Growing community of inventors

Los Angeles, CA, United States of America

Christian A Gutierrez