Medical reservoir level sensor

Patent metadata

Field	Value
Publication number	US-2016334261-A1
Application number	US-201415112516-A
Country	US
Kind code	A1
Filing date	Dec 19, 2014
Priority date	Jan 21, 2014
Publication date	Nov 17, 2016
Grant date	—

Abstract

Devices can be used for detecting a level of a fluid in a medical fluid reservoir and for controlling the level. For example, this documents describes devices and methods for controlling the flow rate of a medical pump, and/or the occlusion amount of a medical fluid tube, based on the detected level of fluid in the medical reservoir.

First claim

1 .- 14 . (canceled)

15 . A medical fluid reservoir comprising:
a reservoir shell defining an interior space that is configured to receive a medical fluid; and two or more individual level sensors at least partially disposed in the interior space, each of the two or more individual level sensors comprising a wire that is configured to be immersed in the medical fluid such that a resistivity of the wire is indicative of a level of the medical fluid in the interior space.

16 . The medical fluid reservoir of claim 15 , wherein the wire is a loop, and wherein an amount of the wire loop that is immersed in the medical fluid corresponds to the resistivity of the wire loop.

17 . The medical fluid reservoir of claim 16 , wherein the amount of the wire loop that is immersed in the medical fluid is inversely proportional to the resistivity of the wire loop.

18 . The medical fluid reservoir of claim 16 , wherein the medical fluid is an electrolyte.

19 . The medical fluid reservoir of claim 18 , wherein the medical fluid comprises human blood.

20 . The medical fluid reservoir of claim 15 , wherein the two or more individual level sensors comprises three or more individual level sensors, the three or more individual level sensors having differing lengths.

21 . The medical fluid reservoir of claim 15 , wherein the two or more individual level sensors comprises five or more individual level sensors, the five or more individual level sensors having differing lengths.

22 . A method of controlling a medical pump, wherein the method comprises:
measuring a resistivity of two or more individual level sensors at least partially disposed in an interior space of a reservoir containing a medical fluid, each of the two or more individual level sensors comprising a wire that is configured to be immersed in the medical fluid such that a resistivity of the wire is indicative of a level of the medical fluid in the interior space; comparing the measured resistivity of adjacent individual level sensors of the two or more individual level sensors to determine a resistivity difference between adjacent individual level sensors; comparing the determined resistivity difference between adjacent individual level sensors to a pre-established threshold value or range of resistivity; determining the level of the medical fluid in the interior space based on a particular resistivity difference between adjacent individual level sensors being greater than the pre-established threshold value or range of resistivity; and in response to the determining, sending a pump speed adjustment signal to a pump speed control system that controls the speed of the medical pump that propels the medical fluid.

23 . The method of claim 22 , wherein the wire is a loop, and wherein an amount of the wire loop that is immersed in the medical fluid corresponds to the resistivity of the wire loop.

24 . The method of claim 23 , wherein the amount of the wire loop that is immersed in the medical fluid is inversely proportional to the resistivity of the wire loop.

25 . The method of claim 22 , wherein the medical fluid is an electrolyte.

26 . The method of claim 25 , wherein the medical fluid comprises human blood.

27 . The method of claim 22 , wherein the two or more individual level sensors comprises three or more individual level sensors.

28 . The method of claim 22 , wherein the two or more individual level sensors comprises five or more individual level sensors.

29 . A medical fluid system comprising:
a reservoir shell defining an interior space that is configured to receive a medical fluid; two or more individual level sensors at least partially disposed in the interior space, each of the two or more individual level sensors comprising a wire that is configured to be immersed in the medical fluid such that a resistivity of the wire is indicative of a level of the medical fluid in the interior space; and a pump system that is configured to pump the medical fluid into or out of the interior space, wherein a speed of the pump system is responsive to a pump speed adjustment input signal.

30 . The medical fluid system of claim 29 , wherein the wire is a loop, and wherein an amount of the wire loop that is immersed in the medical fluid corresponds to the resistivity of the wire loop.

31 . The medical fluid system of claim 30 , wherein the amount of the wire loop that is immersed in the medical fluid is inversely proportional to the resistivity of the wire loop.

32 . The medical fluid system of claim 31 , wherein, in response to a decreased resistivity of the wire loop, the pump speed adjustment input signal causes the speed of the pump system to increase.

33 . The medical fluid system of claim 31 , wherein, in response to an increased resistivity of the wire loop, the pump speed adjustment input signal causes the speed of the pump system to decrease.

34 . The medical fluid system of claim 29 , wherein the two or more individual level sensors comprises three or more individual level sensors, the three or more individual level sensors having differing lengths.

Assignees

• Mayo Foundation

Inventors

• Wilson Iii Donald S

Classifications

• A61M1/3667

  with assisted venous return · CPC title

• F04B2207/00

  External parameters · CPC title

• F04B49/06

  Control using electricity (regulating by means of floats actuating electric switches F04B49/04) · CPC title

• G01F23/241 Primary

  for discrete levels · CPC title

• A61M2205/3389

  Continuous level detection (A61M2205/3393 takes precedence) · CPC title