Optical displacement sensor for infusion devices
First Claim
1. A displacement sensor for a medical fluid pump having a reservoir and a translating piston, the sensor comprising:
- a. a plunger rod coupled to the piston bearing an encoded pattern of encoding features, wherein the encoding features includes a plurality of slots, the spacing of the encoding features from one another defining spaces between such that any two adjacent spaces form a unique sequence;
b. a light source for illuminating the encoded pattern;
c. a detector array for detecting light from the illuminated encoded pattern and generating a detector signal, said detector array configured to detect at least two of said plurality of slots simultaneously; and
d. a processor for determining a displacement of the plunger rod relative to a fiducial reference position based at least on the detector signal.
2 Assignments
0 Petitions
Accused Products
Abstract
An optical sensor for a delivery device having a piston that displaces a substance, such as a fluid, from a reservoir. The optical sensor has a light source and a detector array for imaging encoding features disposed along a plunger rod coupled to the piston. By virtue of the pattern of encoding features, an absolute position of the plunger rod relative to a fiducial position may be determined uniquely. Thus, the volume of fluid remaining in the reservoir, the rate of fluid delivery, and proper loading of the reservoir may be accurately ascertained. Additionally, the encoding may serve to uniquely identify a version of the reservoir which may be supplied in various versions corresponding, for example, to differing concentrations of a therapeutic agent to be dispensed.
-
Citations
19 Claims
-
1. A displacement sensor for a medical fluid pump having a reservoir and a translating piston, the sensor comprising:
-
a. a plunger rod coupled to the piston bearing an encoded pattern of encoding features, wherein the encoding features includes a plurality of slots, the spacing of the encoding features from one another defining spaces between such that any two adjacent spaces form a unique sequence; b. a light source for illuminating the encoded pattern; c. a detector array for detecting light from the illuminated encoded pattern and generating a detector signal, said detector array configured to detect at least two of said plurality of slots simultaneously; and d. a processor for determining a displacement of the plunger rod relative to a fiducial reference position based at least on the detector signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A medical fluid dispensing apparatus comprising:
-
a. a reservoir having a cylindrical inner volume for containing a medical fluid; b. a plunger rod for impelling a piston along a linear axis of motion within the inner volume of the reservoir in order to displace and dispense a measured quantity of medical fluid; c. an encoding pattern of encoding features disposed along the plunger rod in a direction substantially orthogonal to the linear axis of motion of the piston, wherein the encoding features includes a plurality of slots, the spacing of the encoding features from one another defining spaces between such that any two adjacent spaces form a unique sequence; d. an illumination source for illuminating the encoded pattern; e. a detector array for detecting light from the illuminated encoded pattern and generating a detector signal, said detector array configured to detect at least two of said plurality of slots simultaneously; and f. a processor for determining a displacement of the plunger rod relative to a fiducial reference position based at least on the detector signal. - View Dependent Claims (12, 13, 14, 15)
-
-
16. A method for measuring a rate of dispensing a medical fluid by means of a medical fluid pump having a piston driven along an axis of motion within a reservoir of the medical fluid, the method comprising:
-
a. illuminating with an illumination source an encoded pattern of encoding features disposed upon a plunger rod coupled to the piston, wherein the encoding features includes a plurality of slots, the spacing of the encoding features from one another defining spaces between such that any two adjacent spaces form a unique sequence; b. detecting light from the illuminated encoding features and generating a detector signal via a detector array configured to detect at least two of said plurality of slots simultaneously; and c. determining a displacement of the plunger rod relative to a fiducial reference position based at least on the detector signal. - View Dependent Claims (17, 18, 19)
-
Specification