Liquid transport apparatus and bubble determination method

• US 9,347,901 B2
• Filed: 10/25/2013
• Issued: 05/24/2016
• Est. Priority Date: 10/30/2012
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Katase, Makoto
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): Jenkins, Jermaine
• Application Number:
  US14/063,488
• Publication Number:
  US 20140116110A1
• Time in Patent Office: 942 Days
• Field of Search: None
• US Class Current: 1/1
• 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 5/14248 of the skin patch type
• 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 5/16854 by monitoring line pressure
• CPC Class Codes: A61M 5/365 Air detectors A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626
• CPC Class Codes: F04B 19/006 Micropumps F04B43/043 and F04B43/095 take precedence
• CPC Class Codes: F04B 43/1223 the actuating elements, e.g. rollers, moving in a straight line during squeezing
• CPC Class Codes: F04B 43/123 using an excenter as the squeezing element
• CPC Class Codes: G01N 27/02 by investigating impedance

Abstract

A liquid transport apparatus includes a tube for transporting a liquid, plural fingers that push and block the tube, a cam that pushes the fingers in sequence so as to squeeze the tube to transport the liquid, a first electrode and a second electrode that are provided at the tube located further toward the downstream side than a region pushed by the plural fingers, and a determination unit that determines the presence/absence of a bubble on the basis of the impedance between the first electrode and the second electrode.

Claims

1. A liquid transport apparatus comprising:

a tube that transports a liquid;

a plurality of fingers that push and block the tube;

a cam that pushes the fingers in sequence so as to squeeze the tube to transport the liquid;

a first electrode and a second electrode that are provided at the tube located downstream of a region pushed by the plurality of fingers; and

a determination unit that determines presence/absence of a bubble in the liquid transported through the tube based on an impedance between the first electrode and the second electrode.

2. The liquid transport apparatus according to claim 1,

wherein water-repellent treatment is performed to an inner surface of the tube.

3. The liquid transport apparatus according to claim 1,

wherein an alternating voltage is applied to the first electrode and the second electrode when the impedance between the first electrode and the second electrode is measured.

4. The liquid transport apparatus according to claim 1,

wherein in a priming process of filling a flow channel of the liquid transport apparatus with the liquid, it is determined that the priming process is not completed if it is detected that the bubble is present.

5. The liquid transport apparatus according to claim 1, further comprising:

a third electrode,

wherein the determination unit determines a size of the bubble based on the impedance between the first electrode and the second electrode and an impedance between the first electrode and the third electrode or an impedance between the second electrode and the third electrode.

6. A bubble determination method of a liquid transport apparatus including a tube that transports a liquid, a plurality of fingers that push and block the tube, a cam that pushes the fingers in sequence so as to squeeze the tube to transport the liquid, and a first electrode and a second electrode that are provided at the tube, the method comprising:

measuring an impedance between the first electrode and the second electrode; and

determining presence/absence of a bubble in the liquid transported through the tube based on the measured impedance.