Access disconnection systems and methods

• US 7,682,328 B2
• Filed: 01/16/2006
• Issued: 03/23/2010
• Est. Priority Date: 04/10/2002
• Status: Active Grant

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter International Inc.
• Inventors: Han, James, Hartranft, Thomas P., Lasso, Angel, Kelly, Thomas D.
• Primary Examiner(s): Deak; Leslie R
• Application Number:
  US11/331,609
• Publication Number:
  US 20060116623A1
• Time in Patent Office: 1,527 Days
• Field of Search: 604/5.04, 604/4.01, 604/6.06, 604/6.08, 604/6.09, 604/6.16, 604/5.01, 210/645, 210/646, 210/103, 210/85, 210/87, 210/746, 422/44, 738/610.8
• US Class Current: 604/5.04
• 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 1/3669 Electrical impedance measurement of body fluids; transducers specially adapted therefor
• CPC Class Codes: A61M 2205/13 with means for the detection of operative contact with patient, e.g. lip sensor
• CPC Class Codes: Y10S 439/909 Medical use or attached to human body

Abstract

An extracorporeal blood system includes: (i) an extracorporeal blood machine; an extracorporeal blood circuit coupled operably to the machine, the extracorporeal blood circuit including first and second blood lines, the blood lines configured to be in blood flow communication with a patient; (ii) an electrical loop including first and second electrodes placed in contact with blood flowing through the extracorporeal blood circuit; (iii) a device configured to inject an electrical signal into the blood circuit via the loop; and (iv) a third electrode placed in contact with blood flowing through the extracorporeal blood circuit, the third electrode configured to enable a change in an electrical value to be measured so that an access disconnection of the extracorporeal blood circuit from the patient can be measured.

Claims

1. An extracorporeal blood system comprising:

an extracorporeal blood machine;

an extracorporeal blood circuit coupled operably to the machine, the extracorporeal blood circuit including first and second blood lines, the blood lines configured to be in blood flow communication with a patient;

an electrical loop including first and second electrodes placed in contact with blood flowing through the first and second blood lines, respectively;

a device configured to inject an electrical signal into the blood circuit via the loop;

a third electrode placed in contact with blood flowing through the extracorporeal blood circuit, the third electrode configured to enable a change in an electrical value to be measured so that an access disconnection of the extracorporeal blood circuit from the patient can be measured; and

a conductive path between the first and second contacts, forming part of the electrical loop, the conductive path not directly connected to a signal source or a measuring device for providing and measuring the electrical value, respectively.

2. The extracorporeal blood system of claim 1, wherein the signal source includes an induction coil, which is coupled to the extracorporeal blood circuit at the third electrode.

3. The extracorporeal blood system of claim 1, wherein the loop is configured to bypass at least one component of the extracorporeal blood machine.

4. The extracorporeal blood system of claim 3, wherein the bypassed component is selected from the group consisting of:

a bubble trap, a blood pump, a blood treatment device, a dialysis machine and combinations thereof.

5. The extracorporeal blood system of claim 1, wherein the third electrode is coupled capacitively to the first and second blood lines.

6. The extracorporeal blood system of claim 1, wherein the electrical value is of a type selected from the group consisting of:

voltage, resistance, impedance, current, rate of changes thereof and combinations thereof.

7. The extracorporeal blood system of claim 1, wherein the change in electrical value is measured in response to dislodgment of a needle from the patient, the needle coupled to the extracorporeal blood circuit.

8. 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, continuous renal replacement therapy and peritoneal dialysis.

9. The extracorporeal blood system of claim 1, wherein the measuring device is configured to measure the change in electrical value at the third electrode.

10. The extracorporeal blood system of claim 9, further comprising an analyzer coupled operably to the measuring device, the analyzer configured to process a signal derived from the measuring device, the signal indicative of the change in electrical value.