Access disconnection systems and methods

• US 7,959,594 B2
• Filed: 01/25/2006
• Issued: 06/14/2011
• Est. Priority Date: 04/10/2002
• Status: Active Grant

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Inventors: Han, James, Falkvall, Thore, Lamberson, George, Hartranft, Thomas P., Wariar, Ramesh
• Primary Examiner(s): Deak; Leslie R
• Application Number:
  US11/338,988
• Publication Number:
  US 20060184087A1
• Time in Patent Office: 1,966 Days
• Field of Search: 604/4.01, 604/5.01, 604/6.16, 210/646, 210/746
• US Class Current: 604/6.16
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/30 Single needle dialysis ; Reciprocating systems, alternately withdrawing blood from and returning it to the patient, e.g. single-lumen-needle dialysis or single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/3653 Interfaces between patient blood circulation and extra-corporal blood circuit
• CPC Class Codes: A61M 1/3656 Monitoring patency or flow at connection sites; Detecting disconnections
• CPC Class Codes: A61M 1/3659 Cannulae pertaining to extracorporeal circulation
• CPC Class Codes: A61M 1/3661 for haemodialysis
• CPC Class Codes: A61M 1/367 Circuit parts not covered by the preceding subgroups of group A61M1/3621
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3324 PH measuring means
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• 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 5/5086 for indicating if defective, used, tampered with or unsterile

Abstract

Apparatuses, devices, systems and methods for detecting access disconnection are provided. In one embodiment, a medical fluid system includes (i) a medical fluid machine and (ii) a device operable with the medical fluid machine, the device configured to provide electrical contact with a medical fluid, the device including (a) a tube used during dialysis therapy through which the medical fluid can flow, and (b) a conductive element configured to self-sealingly pierce the tube, the conductive element having a first portion exposed to the medical fluid and a second portion external to the tube.

Claims

1. An extracorporeal blood system comprising:

an extracorporeal blood machine including an extracorporeal blood circuit;

an access device enabling the extracorporeal blood circuit to be connected to a patient;

a pair of electrical contacts configured to contact blood as the blood flows through the extracorporeal blood circuit; and

a controller configured to model a total impedance Z according to at least two lumped impedances including (i) a lumped impedance Z_D due to components of the extracorporeal blood machine and (ii) a lumped impedance Z_P due to access of the extracorporeal blood circuit to the patient.

2. The extracorporeal blood system of claim 1, wherein Z_P is due at least to the access device and tubing associated with the extracorporeal blood circuit.

3. The extracorporeal blood system of claim 1, wherein Z_D is due at least to a pump, dialyzer and drip chambers.

4. The extracorporeal blood system of claim 1, wherein the controller is configured to assume Z_P approaches infinity upon dislodgment of the access device from the patient, such that Z becomes at least substantially equal to Z_D.

5. The extracorporeal blood system of claim 1, wherein an electrical contact coupling device is coupled to the extracorporeal blood circuit.

6. The extracorporeal blood system of claim 5, which includes a conductive device including a first member and a second member movably attached to the first member allowing for displacement of the first member and the second member into an open arrangement and a closed arrangement.

7. The extracorporeal blood system of claim 6, wherein the conductive device includes a hinge attached to the first member and the second member at the end.

8. The extracorporeal blood system of claim 5, wherein at least a portion of each of the first and second members is made of a material compatible with an electrical contact provide on the conductive device such that an effective electrical connection can be made.

9. The extracorporeal blood system of claim 1, wherein the extracorporeal blood machine is of a type selected from the group consisting of:

hemodialysis, hemofiltration, hemodiafiltration and continuous renal replacement therapy.