Dripping fluid level detector

• US 4,237,878 A
• Filed: 01/03/1979
• Issued: 12/09/1980
• Est. Priority Date: 01/10/1978
• Status: Expired due to Term

• Current Assignee: Bohsei Enterprise, Omron Tateisi Electronics Co. (Omron Corporation)
• Original Assignee: Bohsei Enterprise, Omron Tateisi Electronics Co. (Omron Corporation)
• Inventors: Kobayashi, Toshiyuki, Kai, Isao, Nakai, Hideharu, Yonemori, Yoshinori
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US06/000,799
• Time in Patent Office: 706 Days
• Field of Search: 128/214 E, 128/214 F, 128/DIG. 12, 128/DIG. 13, 128/227, 340/562, 340/603, 340/606, 340/609, 340/620, 222/23
• US Class Current: 604/122
• 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 5/14 Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
• CPC Class Codes: A61M 5/1418 Clips, separators or the like for supporting tubes or leads
• CPC Class Codes: A61M 5/1684 by detecting the amount of infusate remaining, e.g. signalling end of infusion
• CPC Class Codes: Y10S 128/13 Infusion monitoring

Abstract

Disclosed is a dripping fluid level detector comprising a pair of electrodes oppositely disposed around a drip chamber of a supply passage of dripping medical fluid and a detecting circuit which detects the remaining amount of medical fluid according to changes in the electrostatic capacity caused between said pair of electrodes.

Claims

1. A dripping fluid level detector for use with a fluid passage of a medical fluid dropper comprising:

a drip chamber connected in said fluid passage;

a pair of electrodes oppositely disposed about and in contact with the outer surfaces of said drip chamber for detecting changes in the electrostatic capacity between said electrodes caused by changes in the amount of dripping fluid remaining in said chamber, said electrodes being formed of an elastic substance and being deformable into conformity with the shape of said drip chamber; and

,

an electric circuit for detecting a change in electrostatic capacity existing between said electrodes, which represents a change in the amount of fluid remaining in said chamber, said circuit including an oscillation circuit having an oscillation state which varies in accordance with a change in said electrostatic capacity and means responsive to said oscillator circuit for providing a predetermined output signal when said oscillator state reaches a predetermined condition indicating the dropping of fluid in said chamber below a predetermined amount.

2. A level detector as defined in claim 1, further comprising a pair of covers each supporting a respective one of said electrodes.

3. A level detector as defined in claim 2, wherein said pair of covers are hinged together in a manner permitting opening and closing of said covers to attach or release said electrodes from contact with said dripping chamber.

4. A level detector as defined in claim 3, wherein said covers are formed as a pair of pincers having a pair of holders provided with a spring means therebetween, said spring means biasing said covers into a closed condition surrounding said dripping chamber, said covers being supported thereby to said chamber and being opened by squeezing pressure applied to bring said holders together against the biasing force of said spring.

5. A level detector as defined in claim 4, further comprising a hangar provided on said holders for suspending said electrodes at a desired position.

6. A level detector as defined in claim 1, further comprising a pair of electrostatic shields each provided at the outside of a respective electrode.

7. A dripping level detector for use in a medical fluid passage of a liquid dropper comprising:

a drip chamber provided in said passage;

a pair of hinged covers formed as a pair of pincers having a pair of holders provided with a spring means therebetween, said covers being normally biased to a closing condition by said spring means to surround said drip chamber and being removable from said drip chamber upon opening said covers by pushing the holders towards one another against the force of said spring means;

a pair of electrodes each supported by a respective one of said covers for direct attachment with the outer surface of said drip chamber, said electrodes being made of an elastic substance deformable into conformity with the shape of said drip chamber;

an electric circuit for detecting a change in electrostatic capacity existing between said electrodes, which represents a change in the amount of fluid remaining in said chamber, said circuit including an oscillation circuit having an oscillation state which varies in accordance with a change in said electrostatic capacity and means responsive to said oscillator circuit for providing a predetermined output signal when said oscillator state reaches a predetermined condition indicating the dropping of fluid in said chamber below a predetermined amount;

a pair of electrostatic shield means each provided at the outside of a respective cover; and

,

means for suspending said covers supporting the electrodes at a desired position surrounding said drip chamber.