Sensor device for use in a medical fluid delivery system
View Patent ↗A sensor device for use in a medical fluid delivery system, or an infusion pump device, comprises a fluidic chamber with a deformable cover closing at least an area of the chamber and an optical detection system comprising at least one light emitter for emitting one or more incident light beams and a sensor unit for monitoring one or more reflected light beams is presented. In a pressurized state of the fluidic chamber, the deformable cover is deformed such that it forms an inflexion point area within the deformed cover. The one or more incident light beams emitted by the light emitter are directed on the cover such that the one or more incident light beams are reflected essentially in the inflexion point area.
1. A sensor device comprising:
a fluidic chamber with a deformable cover closing at least one area of the chamber;
an optical detection system comprising at least one light emitter for emitting one or more incident light beams; and
a sensor unit for monitoring one or more reflected light beams, wherein the one or more incident light beams emitted by the light emitter are directed on the cover such that the one or more incident light beams are reflected in an inflexion point area that is formed within the deformable cover upon deformation of the deformable cover in a pressurized state of the fluidic chamber, and wherein the fluidic chamber is part of a disposable unit of a medical fluid delivery system and the optical detection system is part of a reusable unit of a medical fluid delivery system.
2. The sensor device of claim 1 wherein the incident light beams are directed on the cover at an angle α.
3. The sensor device of claim 1 wherein the light emitter is located on a side of the cover which is curved in a convex manner in an increased pressure state of the fluidic chamber.
4. The sensor device of claim 1 wherein one side of the cover is in fluid contact and the light emitter is located on the other side.
5. The sensor device of claim 1 wherein the incident light beam is a parallel light beam.
6. The sensor device of claim 1 wherein the light emitter is a laser diode or a light emitting diode comprising an optical element for parallelizing emitted light beams.
7. The sensor device of claim 1 wherein the sensor unit comprises a dual-element sensor with two photo-elements.
8. The sensor device of claim 7 further comprising an optical element disposed in an optical path from the inflexion point area towards one or both of the first and/or second photo-elements.
9. The sensor device of claim 1 wherein an overall diameter of the one or more incident light beams is selected such that an edge of the beam does not extend beyond a center point of the cover.
10. The sensor device of claim 1 wherein the cover covers an at least partially rounded opening of the fluidic chamber.
11. The sensor device of claim 1 wherein the one or more incident light beams are reflected at an inflection point area located closest to the light emitter.
12. A medical fluid delivery system comprising the sensor device of claim 1 .
13. The medical fluid delivery system of claim 12 wherein the disposable unit comprises an optical element for directing the one or more incident light beams in an angle α on the inflexion point area of the cover.
14. The medical fluid delivery system of claim 13 wherein the disposable unit comprises an optical element for directing the reflected light beam from the inflexion point area to the sensor unit.
15. A disposable unit adapted for use with the medical fluid delivery system of claim 13 .
16. A method for monitoring a pressure change in a fluidic chamber of a medical fluid delivery system using the sensor device of claim 1 , comprising:
directing one or more incident light beams on the inflexion point area of the deformable cover;
detecting one or more reflected light beams reflected from the deformable cover in a non-pressurized state and a pressurized state; and
comparing detection data of the non-pressurized state and the pressurized state to extract the pressure change value.