IP Library Granted Patent US 12697443
Granted Patent B2
US 12697443 · App. 18/195,318 · Granted Aug 4, 2026

Air detection method for pumps with volume measurement

Inventor: Frank Cai (Ontario, CA)
Assignee: CAREFUSION 303, INC.
A61M5/365A61M5/14228G01L1/16A61M2205/3327
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Quick Facts
Patent No.
US 12697443
App. No.
18/195,318
Granted
Aug 4, 2026
Kind
B2
Abstract

Methods of air detection in pumps are described herein. In certain embodiments, a pump for detecting air includes a plunger, a plunger air detection module, a camshaft, and a first biasing member. The plunger is movable to selectively engage a tubing segment with a fluid. The plunger air detection module is disposed within the plunger. The camshaft is configured to move the plunger between an engaged position in contact with the tubing segment and a disengaged position spaced apart from the tubing segment. The first biasing member is configured to urge the plunger toward the tubing segment to maintain contact with the tubing segment in the engaged position.

Claims (32)

1 . A pump for detecting air comprising:

a plunger movable to selectively engage a tubing segment comprising a fluid;

a backer configured to support the tubing segment when the plunger engages the tubing segment;

a plunger air detection module extending within the plunger and configured to transmit a signal;

a backer air detection module within the backer and configured to receive the signal from the plunger air detection module;

a camshaft configured to move the plunger between an engaged position in contact with the tubing segment and a disengaged position spaced apart from the tubing segment; and

a first biasing member configured to urge the plunger toward the tubing segment to maintain contact with the tubing segment in the engaged position, wherein the plunger is urged toward the tubing segment and the backer.

2 . The pump of claim 1 , further comprising:

the backer configured to engage the tubing segment in the engaged position and the disengaged position.

3 . The pump of claim 2 , wherein the backer comprises a channel configured to prevent movement of the tubing segment relative to the pump.

4 . The pump of claim 3 , wherein the channel extends a longitudinal length of the backer.

5 . The pump of claim 4 , wherein the channel is defined by a front wedge and a rear barrier extending therefrom along a longitudinal length of the backer.

6 . The pump of claim 2 , wherein the backer comprises a cutout extending along a longitudinal length thereof.

7 . The pump of claim 6 , wherein the cutout is configured to receive the backer air detection module.

8 . The pump of claim 7 , wherein the backer air detection module is parallel to the plunger air detection module.

9 . The pump of claim 1 , wherein the backer air detection module is configured to receive the signal when the plunger is in the engaged position.

10 . The pump of claim 1 , wherein the plunger air detection module comprises a plurality of elements.

11 . The pump of claim 10 , wherein the plunger air detection module comprises a piezoelectric array of elements.

12 . The pump of claim 1 , further comprising a slot defined in the plunger.

13 . The pump of claim 12 , wherein the plunger air detection module is disposed in the slot.

14 . The pump of claim 1 , wherein the plunger does not deform the tubing segment in the engaged position.

15 . A method comprising:

providing a tubing segment within a pump, the tubing segment comprising a fluid traveling therethrough;

urging a plunger toward the tubing segment and a backer such that the plunger is configured to maintain contact with the tubing segment as the fluid travels therethrough, and the backer is configured to support the tubing segment; and

emitting a signal from a plunger air detection module extending within the plunger through the tubing segment, and receiving the signal by a backer air detection module of the backer.

16 . The method of claim 15 , further comprising the backer air detection module receiving the signal when the plunger is in an engaged position in contact with the tubing segment.

17 . The method of claim 15 , further comprising:

moving the plunger with a camshaft to increase or decrease a cross section of the tubing segment to modulate a rate of flow of the fluid through the tubing segment.

18 . The method of claim 15 , further comprising:

moving the plunger with a camshaft to reduce a cross section of the tubing segment to prevent a flow of fluid through the tubing segment.

19 . The method of claim 15 , wherein the backer air detection module is parallel to the plunger air detection module when the plunger is urged toward the tubing segment to maintain contact with the tubing segment.

20 . The method of claim 15 , wherein the plunger does not deform the tubing segment when the plunger is urged toward the tubing segment to maintain contact with the tubing segment.