ACCESS DISCONNECT DETECTION SYSTEM

• US 20090082646A1
• Filed: 09/21/2007
• Published: 03/26/2009
• Est. Priority Date: 09/21/2007
• 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: Bouton, Chad E.
• Granted Patent: US 8,221,320 B2
• Time in Patent Office: Days
• US Class Current: 600/309
• 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 1/3661 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 2205/15 Detection of leaks
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 5/16836 by sensing tissue properties at the infusion site, e.g. for detecting infiltration detecting tissue temperature for diagnostic purposes A61M39/0247

Abstract

An access site disconnection system and method are disclosed. Radio frequency transmitters and receivers are placed near an access site. When a patient receives dialysis treatment, wetness may arise from blood if the access needle becomes disconnected from the access site. Radio-frequency transmitters are mounted on or near gauze or other absorbent material placed adjacent the access site, as are radio-frequency receivers. After the sensors are placed, the dialysis machine and radio-frequency control circuit may be initialized or baselined, and dialysis treatment, such as hemodialysis, begun. If blood leaks from the access site, such as if the access needle is dislodged, the blood attenuates the radio frequency transmissions, which are detected by the receivers. A signal is sent to a controller or to an output device to raise an alert or sound an alarm.

Claims

1. An access disconnect detector, comprising:

at least one radio-frequency transmitter;

at least one radio-frequency receiver; and

a mount suitable for mounting the at least one radio-frequency transmitter and at least one radio-frequency receiver,

wherein the mount and the at least one transmitter and receiver are configured for positioning adjacent an access site for detecting a presence of blood of a patient, and wherein the access site is positioned between the at least one radio-frequency transmitter and the at least one radio-frequency receiver so that the at least one radio-frequency receiver receives one level of signals from the at least one radio-frequency transmitter when the access site is dry and receives a lower level of signals when the access site is wetted.

2. The access disconnect detector according to claim 1, wherein the mount comprises at least one layer of absorbent material and optionally an adhesive layer.

3. The access disconnect detector according to claim 1, wherein the at least one transmitter and at least one receiver are configured for radio-frequency transmissions from about 1 MHz to about 10 GHz.

4. The access disconnect detector according to claim 1, wherein at least one of the at least one transmitter and receiver comprises a printed radio-frequency inlay.

5. The access disconnect detector according to claim 1, wherein at least one of the transmitter and the receiver comprises a microstrip antenna, a patch antenna, or a planar antenna.

6. The access disconnect detector according to claim 1, wherein the detector is configured to distinguish between blood and perspiration or other moisture.

7. The access disconnect detector according to claim 1, wherein at least one of the transmitter and the receiver comprises an edge-firing or face-firing planar antenna.

8. The access disconnect detector according to claim 1, further comprising a radio-frequency control circuit in operable communication with the transmitter and the receiver, the control circuit configured for sending a signal if blood is detected.

9. The access disconnect detector according to claim 1, wherein the detector further comprises a control circuit, and further comprising an output device configured for raising an alert if blood is detected.

10. The access disconnect detector according to claim 1, wherein the access site is a dialysis access site.

11. The access disconnect detector according to claim 1, wherein the mount comprises a circuit mount selected from the group consisting of a flexible circuit mount and a rigid circuit mount.

12. An access disconnect detector, comprising:

a flexible mount suitable for attaching to a patient;

an array comprising at least one radio-frequency transmitter and at least one radio-frequency receiver mounted on a first side of the mount; and

a pad of absorbent material on the array,

wherein the mount and the at least one transmitter and at least one receiver are configured for positioning adjacent a dialysis access site for detecting a presence of blood of the patient, and wherein the at least one transmitter and at least one receiver are configured so that the at least one receiver receives one level of signals from the at least one transmitter when the at least one transmitter and the at least one receiver are dry and receives a lower level of signals when one of the at least one transmitter and at the least one receiver is wetted with blood.

13. The access disconnect detector according to claim 12, wherein at least one of the at least one transmitter and at least one receiver is a printed inlay, the inlay comprising an antenna.

14. The access disconnect detector according to claim 12, wherein at least one of the plurality of transmitters and receivers comprise antennae.

15. The access disconnect detector according to claim 12, wherein at least one of the at least one transmitter and at least one receiver comprises a planar antenna, a patch antenna, an edge-firing planar antenna, or a microstrip antenna.

16. The access disconnect detector according to claim 12, wherein at least one of the at least one transmitter and at least one receiver has a tapered ground plane.

17. An access disconnect detector, comprising:

at least one radio-frequency transmitter for placement on a person;

at least one radio-frequency receiver for placement on a person; and

a flexible layer adjacent the at least one transmitter and the at least one receiver, wherein the transmitter and the receiver are mounted on a single side of the flexible layer for rapid detection of blood from the person.

18. The access disconnect detector according to claim 17, wherein the flexible layer is configured for placement on the person and further comprising an absorbent pad for mounting adjacent the person and between the person and the at least one transmitter and the at least one receiver.

19. The access disconnect detector according to claim 17, further comprising a controller for controlling sending and receiving signals by the at least one transmitter and the at least one receiver, and further comprising a local output device for raising an alert if blood is detected.

20. A method for detecting an access site disconnection, the method comprising:

placing at least one radio-frequency transmitter and at least one radio-frequency receiver adjacent the access site;

sending a transmission from the at least one radio-frequency transmitter to the least one radio-frequency receiver;

receiving the transmission at a baseline level by the at least one radio-frequency receiver;

periodically repeating the steps of sending and receiving; and

sending a signal if the transmission sent by the at least one radio-frequency transmitter is not received at the baseline level by the at least one of the radio-frequency receiver.

21. The method according to claim 20, wherein the at least one radio-frequency receiver comprises a plurality of radio-frequency receivers adjacent an absorbent layer, and wherein the signal is sent if one or more of the radio-frequency receivers does not receive the signal at the baseline level.

22. The method according to claim 20, further comprising mounting the at least one radio-frequency transmitter on a first side of the access site that is an opposite side of a second side for mounting the at least one radio-frequency receiver.

23. The method according to claim 20, further comprising raising an alarm with an output device if the at least one radio-frequency receiver does not receive the signal at the baseline level.

24. The method according to claim 20, further comprising waiting to send the signal until a minimum number of steps of sending and receiving do not detect the signal at the baseline level.