Vaporizer anesthesia level detector

• US 9,217,658 B2
• Filed: 03/30/2012
• Issued: 12/22/2015
• Est. Priority Date: 03/30/2012
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Kuehl, Kenneth J., Jones, Michael, McHenry, William Breckenridge, Whitman, Shawn Thomas
• Primary Examiner(s): Williams, Hezron E
• Assistant Examiner(s): Eyassu, Marrit
• Application Number:
  US13/436,265
• Publication Number:
  US 20130255676A1
• Time in Patent Office: 1,362 Days
• Field of Search: 733/23, 733/04.C, 732/90.R, 733/25, 324/691
• US Class Current: 1/1
• CPC Class Codes: A61M 16/18 Vaporising devices for anaesthetic preparations
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3389 Continuous level detection A61M2205/3393 takes precedence
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/8206 battery-operated
• CPC Class Codes: G01F 23/02 by gauge glasses or other apparatus involving a window or transparent tube for directly observing the level to be measured or the level of a liquid column in free communication with the main body of the liquid
• CPC Class Codes: G01F 23/265 for discrete levels
• CPC Class Codes: G01F 23/266 measuring circuits therefor
• CPC Class Codes: G01F 23/268 mounting arrangements of probes

Abstract

A vaporizer including a reservoir for storing an anesthetic liquid agent and a vaporizing element configured to vaporize the anesthetic liquid agent. A level detector is located outside of and adjacent to the exterior of the reservoir. The level detector includes at least one electrical field sensor configured to provide an output voltage signal based upon the capacitance of material within the reservoir proximate the electrical field sensor. The vaporizer includes a display providing a visual indication of the amount of liquid anesthetic agent in the reservoir.

Claims

1. A level detector for use with an existing liquid anesthesia vaporizer having a sight glass operatively connected to a reservoir configured to hold a liquid anesthetic agent including, the level detector comprising:

a housing supporting at least one electrical field sensor configured to provide an output voltage signal based upon the capacitance of material proximate the electrical field sensor;

a power source;

a display;

an input device; and

a processing unit configured to obtain the voltage output of the electrical field sensor, wherein the processing unit is configured to obtain and store a first sum of the output voltage of all of the electrical field sensors when the reservoir is full of a liquid anesthetic agent and, periodically obtain a subsequent sum of the output voltage of all of the electrical field sensors and display the amount of liquid anesthetic agent remaining in the reservoir as a function of the ratio of the subsequent sum and the first sum

the housing being positioned proximate the vaporizer such that the electrical field sensor is adjacent the sight glass, the electrical field sensor configured to provide an output voltage signal that changes as the capacitance of material within the sight glass changes.

2. The level detector of claim 1, wherein the at least on electrical field sensor includes at least four electrical field sensors arranged along a vertical axis.

3. The level detector of claim 1 wherein the at least one electrical field sensor is more than two electrical field sensors, each electrical field sensors being evenly spaced from an adjacent electrical field sensor and arranged along a vertical axis.

4. A level detector for use with an existing liquid anesthesia vaporizer having a sight glass operatively connected to a reservoir configured to hold a liquid anesthetic agent including, the level detector comprising:

a housing supporting at least one electrical field sensor configured to provide an output voltage signal based upon the capacitance of material proximate the electrical field sensor;

the housing being positioned proximate the vaporizer such that the electrical field sensor is adjacent the sight glass, the electrical field sensor configured to provide an output voltage signal that changes as the capacitance of material within the sight glass changes;

wherein the housing includes a power source;

a display; and

an input device; and

a processing unit;

wherein the processing unit is configured to store in a memory a predetermined output value for each electrical field sensor, the processor receiving voltage output values from each electrical field sensor and providing instructions to the display to provide a visual indication of the percent of anesthetic remaining in the reservoir as a ratio of the number of electric field sensors below the predetermined value and the total number of electric field sensors.

5. A level detector for use with an existing liquid anesthesia vaporizer having a sight glass operatively connected to a reservoir configured to hold a liquid anesthetic agent including, the level detector comprising:

a housing supporting at least one electrical field sensor configured to provide an output voltage signal based upon the capacitance of material proximate the electrical field sensor;

the housing being positioned proximate the vaporizer such that the electrical field sensor is adjacent the sight glass, the electrical field sensor configured to provide an output voltage signal that changes as the capacitance of material within the sight glass changes;

wherein the housing includes a power source;

a display; and

an input device; and

a processing unit;

wherein the processing unit is configured to receive an output voltage from each electrical field sensor and execute instructions from memory to calculate an average output voltage of all of the electrical field sensors, the processing unit executing instructions to determine the number of electrical field sensors below the average value output voltage and provide the ratio of electrical field sensors below the average value to the total number of electrical field sensors.

6. A level detector for use with an existing liquid anesthesia vaporizer having a sight glass operatively connected to a reservoir configured to hold a liquid anesthetic agent including, the level detector comprising:

a housing supporting at least one electrical field sensor configured to provide an output voltage signal based upon the capacitance of material proximate the electrical field sensor;

the housing being positioned proximate the vaporizer such that the electrical field sensor is adjacent the sight glass, the electrical field sensor configured to provide an output voltage signal that changes as the capacitance of material within the sight glass changes;

wherein the housing includes a power source;

a display; and

an input device; and

a processing unit;

wherein the processing unit is configured to store an empty voltage value defined by the aggregate of the voltage output of each electrical field sensor when the reservoir is empty of an anesthetic liquid agent and full of air and store a full voltage value defined by the aggregate of the voltage output of each electrical field sensor when the reservoir is full of an anesthetic liquid agent, wherein the processing unit derives a differential voltage value as the difference between the full voltage value and the empty voltage value, the processing unit calculates a sample voltage value as the aggregate voltage output from all of the electrical field sensors at a time during use of the liquid anesthesia vaporizer and provides the percent of anesthetic remaining in the reservoir as the difference between the sample voltage value and the empty voltage value divided by the differential voltage value.