Multifunction Capacitive Sensor for Medical Pump

• US 20140171868A1
• Filed: 12/12/2013
• Published: 06/19/2014
• Est. Priority Date: 12/13/2012
• Status: Active Grant

• Current Assignee: Zyno Medical, LLC
• Original Assignee: Zyno Medical, LLC
• Inventors: Zhang, Mei, Lee, Chaoyoung
• Granted Patent: US 9,327,072 B2
• Time in Patent Office: Days
• US Class Current: 604/111
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 5/14228 with linear peristaltic action, i.e. comprising at least three pressurising members or a helical member
• CPC Class Codes: A61M 5/16831 Monitoring, detecting, signalling or eliminating infusion flow anomalies low-level float-valves causing cut-off A61M5/40; indicating or recording presence, absence or direction of flow in general G01P13/0066
• CPC Class Codes: A61M 5/365 Air detectors A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626
• CPC Class Codes: A61M 5/5086 for indicating if defective, used, tampered with or unsterile

Abstract

A medical pump or the like provides for a multi-function flow monitor that provides for capacitive plates positioned on opposite sides of the IV line to sense changes in the electrical environment within the IV line to deduce IV line pressure, the presence of IV fluid bubbles, the presence of the IV line within the pump, and/or correct pump operation. Each of these conditions may be determined by different analysis of the capacitance across the capacitive plates.

Claims

1. A medical liquid delivery system comprising:

a housing adapted to receive an IV line within a housing portion;

capacitive sensor electrodes positioned in the housing portion to flank the received IV line, and

control electronics communicating with the capacitive sensor electrodes to measure capacitance across the capacitive sensor electrodes and to sense at least one condition of a pressure of medical fluid within a received IV line, a bubble within medical fluid within a received IV line, and a presence of a fluid-filled received IV line between the capacitive sensor electrodes.

2. The medical liquid delivery system of claim 1 wherein the control electronics sense pressure of medical fluid within the IV line by sensing capacitive changes caused by increase of water dielectric between the capacitive sensor electrodes caused by diametric distention of the received IV line.

3. The medical liquid delivery system of claim 2 wherein the control electronics includes calibration data relating change in capacitance to pressure-induced diametric distention of the received IV line for a particular IV line and determines the pressure of the medical fluid within the IV line by applying a sense-capacitive value to the calibration data.

4. The medical liquid delivery system of claim 3 wherein the control electronics includes signal filtering electronics removing short-term perturbations in the measured capacitance across the capacitive sensor electrodes.

5. The medical liquid delivery system of claim 1 wherein the control electronics sense a bubble within the medical fluid within the received IV line by detecting capacitive changes caused by displacement of water dielectric between the capacitive sensor electrodes by the presence of a bubble.

6. The medical liquid delivery system of claim 5 wherein the control electronics includes a high pass filter followed by a threshold detector for distinguishing a bubble within the medical fluid within the received IV line from pressure changes.

7. The medical liquid delivery system of claim 1 wherein the control electronics senses the presence of a fluid-filled received IV line by sensing an increase in water dielectric between the capacitive sensor electrodes with insertion of an IV line between the capacitive sensor electrodes.

8. The medical liquid delivery system of claim 7 wherein the control electronics includes a threshold detector discriminating between capacitance of air versus a fluid filled IV line between the capacitive sensor electrodes.

9. The medical liquid delivery system of claim 1 further including an alarm and wherein the control electronics triggers the alarm based on at least one condition.

10. The medical liquid delivery system of claim 1 further including a pump supported by the housing and receiving a portion of the IV line to pump fluid through the IV line and wherein the control electronics further communicates with the capacitive sensor electrodes to sense pressure fluctuation caused by operation of the pump.

11. The medical liquid delivery system of claim. 1 further including an IV line received by the housing.

12. The medical liquid delivery system of claim 1 wherein the capacitive sensor electrodes are fixed in separation.

13. The medical liquid delivery system of claim 12 wherein capacitive sensor electrodes are attached to the housing to be retained in the housing with removal of the IV line.

14. The medical liquid delivery system of claim 11 wherein the IV line provides an attachment coupling for sterile attachment to an IV bag and for sterile attachment to a hypodermic needle.

15. A medical liquid delivery system comprising:

a housing adapted to receive an IV line within a housing portion;

an optical sensor positioned in the housing portion to flank the received IV line, and

control electronics communicating with the optical sensor to sense at least one condition of a pressure of medical fluid within the IV line and a. presence of a fluid-filled IV line between the capacitive sensor electrodes.