# US 7,874,999 B2 · Detecting access disconnect using needle sleeve > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,874,999 B2 - Document ID: US7874999B2 - Status: Granted - Kind: B2 - Application number: 11/860,052 - Filed: 2007-09-24 - Published: 2009-03-26 - Granted: 2011-01-25 - Earliest claimed: 2007-09-24 - Assignees: Baxter International Inc.; Baxter Healthcare S.A. - Inventors: Donald Busby - Web page: https://patentgrep.com/patent/US7874999B2 ## CPC - A61M 1/3656: {Monitoring patency or flow at connection sites; Detecting disconnections} - A61B 5/15003: {for venous or arterial blood} - A61B 5/150396: {Specific tip design, e.g. for improved penetration characteristics} - A61B 5/150503: {Single-ended needles (hollow piercing element tip design A61B5/150396)} - A61B 5/150633: {Protective sleeves which are axially extensible, e.g. sleeves connected to, or integrated in, the piercing or driving device; pivotable protective sleeves} - A61B 5/15074: {Needle sets comprising wings, e.g. butterfly type, for ease of handling} - A61B 5/15087: {short range, e.g. between console and disposable (using implanted devices A61B5/150877)} - A61B 5/150961: {Means for the detection of the presence or absence of a module, a component or an abnormal condition; detection of leaks} - A61B 5/153: {Devices} specially adapted for taking samples of venous or arterial blood, e.g. with syringes - A61M 1/3653: {Interfaces between patient blood circulation and extra-corporal blood circuit} - A61M 1/3655: {Arterio-venous shunts or fistulae} - A61M 2205/13: with means for the detection of operative contact with patient, e.g. lip sensor - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract An access needle for extracorporeal therapy is equipped with a mount and a sleeve having a metal or magnetic component at its distal end. The mount includes a sensor for detecting when the distal end is pressed against the mount. The sensor is a hall-effect sensor or a proximity sensor. When therapy is begun, the sleeve is rolled up and urged against the mount, exposing the needle for use with the patient. While the sleeve, and the piece of metal or magnet, remains in contact with the sensor, the needle has not been dislodged and therapy may continue. If the needle is dislodged, the sleeve pushes away from mount, moving the metal or magnet away from the sensor. The sensor notes the dislodgement and sends a signal to alert the patient or a caregiver. ## Claims ### Claim 1 A method of detecting a needle disconnection, the method comprising: providing a needle having a mount with a sensor and a sleeve with a metallic target, the sensor configured for detecting the metallic target; placing the needle into an extracorporeal blood processing access site; urging the sleeve against the mount, thereby placing at least a portion of the metallic target near the sensor; taking a reading of the sensor after the metallic target is urged against the mount; monitoring the access site by taking additional readings of the sensor during an extracorporeal blood processing therapy; and sending a signal if a reading consistent with absence of the target from the sensor is detected, thereby indicating dislodgement of the needle. ### Claim 2 (depends on 1) The method of claim 1, further comprising taking a baseline reading of the sensor before the step of urging the sleeve against the mount. ### Claim 3 (depends on 1) The method of claim 1, wherein the signal is sent to a local output device to alert a person or to sound an alarm. ### Claim 4 (depends on 1) The method of claim 1, wherein the sensor is a hall-effect sensor or a proximity sensor. ### Claim 5 A method for detecting needle disconnection at an access site, the method comprising: providing an access needle with an electroactive sleeve and a sensor on a mount of the access needle, wherein the sensor is configured to detect metal or a magnet on the sleeve; mounting the access needle on the access site of a patient and pressing the sleeve toward the mount; taking a reading of the sensor with the pressed sleeve; monitoring the access site during a therapy procedure by taking additional readings with the sensor; and sending a signal if a reading indicative of needle dislodgement is taken. ### Claim 6 (depends on 5) The method of claim 5, further comprising taking a first baseline reading of the sensor and the sleeve while the sleeve covers the needle, and saving data of the first baseline reading for comparison with the baseline reading. ### Claim 7 (depends on 5) The method of claim 5, further comprising sending a local alert as a result of sending the signal. ### Claim 8 (depends on 5) The method of claim 5, further comprising saving data of the reading. ### Claim 9 A system for detecting needle dislodgement, the system comprising: an access needle suitable for mounting near an access site for extracorporeal therapeutic blood processing, the access needle including a mount; a sleeve having an electromagnetic target, the sleeve positioned over the needle and adjacent the mount; a sensor on the mount for detecting the electromagnetic element; and a communications circuit in communication with the sensor, wherein the needle is configured for placing into the access site, the sleeve is configured for pressing against the mount, the sensor is configured for detecting the electromagnetic element, and the communications circuit is configured for sending data indicative of a position of the electromagnetic element with respect to the sensor. ### Claim 10 (depends on 9) The system according to claim 9, wherein the electromagnetic target is selected from the group consisting of magnet or a piece of metal placed on a distal end of the sleeve, and metallic or magnet wire embedded within the sleeve. ### Claim 11 (depends on 9) The system according to claim 9, wherein the sensor is selected from the group consisting of a hall-effect sensor, a proximity sensor, and a magnetic sensor. ### Claim 12 (depends on 9) The system according to claim 9, wherein the sleeve has a shape of a thin tube or bellows. ### Claim 13 A system for detecting needle dislodgement, the system comprising: a needle with a mount suitable for mounting near an access site for an extracorporeal blood therapy; a sleeve having a metallic or magnetic target, the sleeve positioned over the needle and adjacent the mount; a sensor on the mount for detecting the metallic or magnetic target; and a control circuit connected to the sensor, wherein the needle is configured for placing into the access site, the sleeve is configured for pressing against the mount, and the control circuit is configured for taking readings of the sensor indicative of a position of the metallic or magnetic target with respect to the sensor. ### Claim 14 (depends on 13) The system according to claim 13, further comprising a local output device selected from the group consisting of a video screen and a speaker. ### Claim 15 (depends on 13) The system according to claim 13, further comprising a hemodialysis machine for providing the extracorporeal therapy. ### Claim 16 (depends on 13) The system according to claim 13, wherein the sleeve comprises a bellows made from a thin plastic or elastomeric material. ### Claim 17 (depends on 13) The system according to claim 13, wherein the metallic or magnetic target is positioned near a distal end of the sleeve. ### Claim 18 (depends on 13) The system according to claim 13, wherein a shape of the metallic or magnetic target is selected from the group consisting of a thin cylinder or an arc. ### Claim 19 (depends on 13) The system according to claim 13, wherein the sensor is a hall-effect sensor, a capacitance sensor, an inductance sensor, or a magnet sensor.