Tracking and controlling fluid delivery from chamber

摘要

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.

主权项

1. A fluid dosing device for delivering one or more doses of fluid comprising:
a chamber configured to contain fluid; a chamber compressor configured to controllably apply pressure to fluid within the chamber; an outlet from the chamber configured to allow fluid to escape from the chamber when pressure is applied to the fluid; and an impedance detection system configured to detect changes in the electrochemical impedance of fluid within the chamber caused by changes in the volume of the fluid caused by fluid escaping the chamber, wherein one or both of the following:
the impedance detection system includes at least two physically-separated electrodes that do not move in response to fluid escaping the chamber; orthe impedance detection system detects an increase in the electrochemical impedance of the fluid in response to fluid escaping the chamber.