Electromagnetic induction access disconnect sensor

• US 8,114,043 B2
• Filed: 07/25/2008
• Issued: 02/14/2012
• Est. Priority Date: 07/25/2008
• 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: Muller, Matthew R.
• Primary Examiner(s): Deak, Leslie
• Assistant Examiner(s): Wiest, Philip R
• Application Number:
  US12/180,318
• Publication Number:
  US 20100022935A1
• Time in Patent Office: 1,299 Days
• Field of Search: 604 401- 616, 604/65, 604/67, 210/85, 210/87, 210/103, 210645-646
• US Class Current: 604/6.04
• CPC Class Codes: A61M 1/3653 Interfaces between patient blood circulation and extra-corporal blood circuit
• CPC Class Codes: A61M 1/3655 Arterio-venous shunts or fistulae
• CPC Class Codes: A61M 1/3656 Monitoring patency or flow at connection sites; Detecting disconnections
• CPC Class Codes: A61M 1/3661 for haemodialysis
• CPC Class Codes: A61M 2205/13 with means for the detection of operative contact with patient, e.g. lip sensor
• CPC Class Codes: A61M 2205/3561 local, e.g. within room or hospital
• CPC Class Codes: A61M 2205/3569 sublocal, e.g. between console and disposable
• CPC Class Codes: A61M 2205/3592 using telemetric means, e.g. radio or optical transmission

Abstract

A connection of a patient'"'"'s vascular system to an extracorporeal blood treatment machine is monitored to ensure the patient'"'"'s safety during a procedure. The procedure may be hemodialysis, apheresis, plasmapheresis, a coronary by-pass operation, or other procedure. To ensure safe electrical connection, a contact and a return are connected via a conductive connection into the extracorporeal blood circuit. A current is then generated between the contact and the return and is monitored by a non-contact sensor near an access site of the patient. If the current or other quantity related to the current changes significantly, a signal is sent to the machine or a controller to notify a caregiver or a medical professional. The signal may also be sent to immediately stop a blood pump or other component of the machine.

Claims

1. An access disconnect system, comprising:

a blood processing machine including a blood filter and a blood pump;

first and second conductive contacts located in tubing of the blood processing machine on an arterial side of the blood filter, the first conductive contact located upstream of the blood pump, and the second conductive contact located downstream of the blood pump, the first and second conductive contacts configured to form a conductive connection between a vascular system of a patient and the blood processing machine;

a source of time-varying electric current connected to said first conductive contact;

a non-contact sensor for positioning atop an access site of the patient, near the vascular system of the patient, or near tubing leading to the blood processing machine, the non-contact sensor configured for detecting a value of a quantity corresponding to the current; and

a transmitter operably connected to the non-contact sensor for sending a signal indicative of the value to a controller of the blood processing machine.

2. The access disconnect system according to claim 1, wherein the signal is selected from the group consisting of a signal indicating the quantity or a signal indicating whether the quantity is within preselected limits.

3. The access disconnect system according to claim 1, wherein if the signal indicative of the value exceeds a preselected limit, a controller of the blood processing machine is configured to automatically (i) actuate a line clamp, or (ii) stop the blood pump.

4. The access disconnect system according to claim 1, wherein the sensor is selected from the group consisting of a hall-effect sensor, an induction coil, a capacitive sensor and an induction sensor.

5. The access disconnect system according to claim 1, wherein the time varying electric current is 10 microamperes or less.

6. The access disconnect system according to claim 1, wherein the blood processing machine is a hemodialysis machine and the blood filter is a dialyzer.

7. An access disconnect system, comprising:

a blood processing machine including a blood filter and a blood pump;

first and second conductive contacts in tubing leading to the blood processing machine on an arterial side of the blood filter, the first conductive contact located upstream of the blood pump, and the second conductive contact located downstream of the blood pump, the first and second conductive contacts configured to form a conductive connection between a vascular system of a patient and the blood processing machine;

a source of time-varying electric current connected to said first conductive contact;

a non-contact sensor mounted to a wristband for positioning atop an access site of the patient or near the vascular system of the patient, the non-contact sensor configured for detecting a value of a quantity corresponding to the current; and

a wireless transmitter operably connected to the non-contact sensor for sending a signal indicative of the value to a controller of the blood processing machine.

8. The access disconnect system according to claim 7, further comprising a line clamp on tubing leading to and from the blood processing machine.

9. The access disconnect system according to claim 7, further comprising a current sensing circuit on tubing connected to the blood processing machine.

10. The access disconnect system according to claim 7, further comprising a current impedance circuit on tubing connected to the blood processing machine.

11. The access disconnect system according to claim 7, wherein the blood processing machine is a hemodialysis machine and the blood filter is a dialyzer.