Method and apparatus for leak detection in a fluid line
First Claim
1. A leak detector comprising:
- at least one actuator controlled by a controller, said at least one actuator being configured to control pressure in a blood circuit, said controller configured to control flow in said blood circuit and detect a loss of integrity in said blood circuit, by;
delivering blood to a patient through the blood circuit during first time including applying a positive gauge pressure to said circuit;
applying a negative pressure to said blood circuit during second time;
detecting a presence of air in said blood circuit during at least a portion of said second time or after said second times, such that air infiltrating said blood circuit during said second time as a result of said negative pressure and a presence of a leak is detected.
11 Assignments
0 Petitions
Accused Products
Abstract
One of the most significant safety concerns in the automation of extracorporeal blood treatments such as dialysis is the risk of blood leakage. Such systems draw blood at such a high rate that a loss of integrity in the blood circuit can be catastrophic. The most reliable leak detection method known is the detection of infiltrated air in a blood line, but this only works in blood lines under negative pressure. According to the invention, a leak detector for return lines is provided by periodically generating a negative pressure, which may be brief or at a 50% duty cycle, in the blood return line to draw air into it and thereby reveal the leaks using an air sensor. Although the return line is ordinarily under positive pressure, during the negative pressure cycle, the blood return line draws air through any leaks or disconnects. If air is detected, the system is shut down and an alarm generated.
296 Citations
89 Claims
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1. A leak detector comprising:
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at least one actuator controlled by a controller, said at least one actuator being configured to control pressure in a blood circuit, said controller configured to control flow in said blood circuit and detect a loss of integrity in said blood circuit, by;
delivering blood to a patient through the blood circuit during first time including applying a positive gauge pressure to said circuit;
applying a negative pressure to said blood circuit during second time;
detecting a presence of air in said blood circuit during at least a portion of said second time or after said second times, such that air infiltrating said blood circuit during said second time as a result of said negative pressure and a presence of a leak is detected. - View Dependent Claims (2, 3, 4, 5, 6, 7)
said applying includes reversing a direction of flow of blood in said blood circuit;
said detecting includes detecting air with an air sensor located to detect air at a specified position in said blood circuit; and
a duration of said second time is at least long enough to insure that blood will ultimately flow from a terminus of said blood circuit to said specified position, whereby leakage of blood in said blood circuit at least between said specified position and said terminus is assured.
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8. A leak detector, comprising:
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a mechanism operative to reverse flow in a blood circuit configured to return blood to a patient such that a negative pressure is generated in said blood circuit;
an air sensor positioned with respect to said blood circuit to detect air drawn into said blood circuit in the event of a loss of integrity in said blood circuit;
a controller connected to control said mechanism such that said negative pressure is of sufficient magnitude and duration as to insure that blood at a remote end of said blood circuit connected to said patient is drawn to point where it is detectable by said air sensor. - View Dependent Claims (9, 10, 11, 12)
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13. A leak detector connectable to a blood processing machine that has an access blood circuit connectable to a patient to remove blood from, and deliver blood to, said patient;
- a process blood circuit including a treatment component for treating blood circulated through said process blood circuit, said leak detector comprising;
a reversible conveyance connected to move blood through said process and access blood circuits;
an air detector in said access circuit;
a controller configured to reverse said conveyance periodically to draw air into any leaks in said blood circuit and to control said conveyance such that said air is moved to said air detector, whereby a leak in said access blood circuit may be detected. - View Dependent Claims (14, 15, 16, 17)
- a process blood circuit including a treatment component for treating blood circulated through said process blood circuit, said leak detector comprising;
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18. A leak detector connectable to a device operative to control a flow of blood through a blood circuit, said leak detector including a controller programmed to implement a method of detecting a leak in a fluid circuit supplying fluid to a patient, comprising the steps of:
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delivering fluid to a patient through a circuit during a first time;
applying a negative pressure to said blood circuit during a second time;
detecting a presence of air in said fluid circuit during at least a portion of said second time or after said second time such that air infiltrating said fluid circuit during said second time as a result of said negative pressure is detected. - View Dependent Claims (19, 20, 21, 22, 23, 24)
said step of applying includes reversing a direction of flow of fluid in said fluid circuit;
said step of detecting includes detecting air with an air sensor located to detect air at a specified position in said fluid circuit; and
a duration of said second time is at least long as required to cause said fluid to flow from a terminus of said fluid circuit to said specified position.
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25. A tubing set for a leak detecting blood treatment device, comprising:
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draw and return lines connectable to at least one access of a patient for the draft and return of blood;
at least a body of a four-way valve with four ports, at least two of which are sealingly connected to said draw and return lines respectively;
arterial and venous lines connectable to a blood processing machine, said arterial and venous lines being connected, respectively, to two others of said four ports.
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26. A leak detection device connectable to a fluid infusion or treatment system, comprising:
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a support for a fluid circuit configured to convey fluid between a source and an outlet for connection to a patient;
at least an actuator operative to control a portion of said fluid circuit such that a negative pressure can be selectively generated in an outlet portion of said fluid circuit at selected times;
a controller connected to control said actuator and configured to generate a negative pressure in said outlet portion automatically and repeatedly during the course of a treatment of said patient such that a predefined volume of fluid is displaced in a reverse direction;
said controller being further configured to control said actuator such that, at other times, a positive pressure is permitted in said outlet portion. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
said source includes an air sensor and a source fluid circuit leading to said air sensor, said source fluid circuit being one of connected and connectable to said source;
said controller is configured such that said predefined volume of fluid is sufficient to insure that air infiltrating at said terminus of said outlet portion reaches a point of detectablility by said air sensor.
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33. A device as in claim 32, wherein said fluid is blood.
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34. A device as in claim 26, wherein said controller is configured such that said negative pressure in said outlet portion is generated with such regularity that no more than a predetermined volume of said fluid is conveyed through said outlet portion before said negative pressure is again generated.
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35. A device as in claim 34, wherein said fluid is blood.
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36. A device as in claim 26, further comprising an air sensor positioned to detect air in said fluid circuit when said fluid flows in reverse responsively to said controller.
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37. A device as in claim 36, wherein said fluid is blood.
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38. A device as in claim 36, wherein said controller is configured such that said predefined volume of fluid is sufficient to insure that air infiltrating at said terminus of said outlet portion reaches a point of being detectable by said air sensor.
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39. A device as in claim 38, wherein said fluid is blood.
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40. A device as in claim 38, further comprising at least one of a fluid flow halting actuator configured to halt flow in said fluid circuit and an alarm, said controller being configured to actuate said at least one a of a fluid flow halting actuator configured to halt flow in said fluid circuit and an alarm responsively to a signal from said air sensor.
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41. A device as in claim 40, wherein said fluid is blood.
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42. A leak detector comprising:
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a controller configured to detect a leak in a fluid infusion or treatment system that includes a source of fluid to be pumped into a patient;
the controller drawing from said source and conveying said fluid from said source to said patient during a first time and automatically regularly generating a negative pressure such that said fluid is drawn in a reverse direction away from said patient creating a reverse flow of said fluid and one detecting a presence and a flow of air into said fluid infusion system. - View Dependent Claims (43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53)
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54. A leak detector for a sterile contiguous fluid line for infusing a patient, the fluid line including a draw line connectable to at least one patient access and a return line connectable to said at least one patient access, said detector comprising:
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a portion adapted to be interoperable with a pump actuator such that fluid may be conveyed therethrough;
a filter, or filter connectors to permit connection to a filter, to complete a closed fluid circuit joining said draw and return lines;
at least a wetted portion of a device configured to generate a negative pressure in said return line, whereby a flow through said return line may be reversed. - View Dependent Claims (55, 56)
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57. A leak detecting replacement kit for infusing a patient, the replacement kit including a blood line with a draw line connectable to at least one patient blood access, a return line connectable to said at least one patient blood access, a portion adapted to be interoperable with a pump actuator such that fluid may be conveyed therethrough, a filter, or filter connectors to permit connection to a filter, to complete a closed fluid circuit joining said draw and return lines;
- instructions for using said blood line providing for the installation of said adapted to be interoperable with a pump actuator into a location such that it becomes interoperable with a reversible pump.
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58. A leak detecting replacement kit for infusing a patient, comprising:
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a blood line including;
a draw line connectable to at least one patient blood access;
a return line connectable to said at least one patient blood access;
a portion adapted to be interoperable with a flow reversing actuator;
a filter, or filter connectors to permit connection to a filter, to complete a closed fluid circuit joining said draw and return lines;
instructions for using said blood line providing for the installation of said portion adapted to be interoperable with flow reversing actuator into a device with a flow reversing actuator. - View Dependent Claims (59)
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60. A leak detector for an infusion device for delivering a fluid to a patient, the device including a circuit including a pump, a source end and a delivery end joined by said pump, comprising:
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a mechanism to reverse flow at least at said delivery end;
an air detector in said circuit;
said mechanism being controlled such that said mechanism is actuated to reverse said flow automatically and regularly and, at each instance of reversing said flow, to displace enough fluid to transport air infiltrating said circuit at said delivery end to said air detector. - View Dependent Claims (61)
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62. A leak detector with at least one actuator and a controller programmed to implement a method of detecting a loss of integrity in a liquid circuit, comprising the steps of:
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conveying liquid through a circuit during first time;
said step of conveying including applying a positive gauge pressure to said circuit;
regularly applying a negative pressure to said circuit during second time;
detecting a presence of air in said liquid circuit during at least a portion of said second time or after said second time, such that air infiltrating said circuit during said second time, as a result of said negative pressure and a presence of a leak, is detected. - View Dependent Claims (63, 64, 65, 66, 67, 68, 69)
said step of applying includes reversing a direction of flow of liquid in said circuit;
said step of detecting includes detecting air with an air sensor located to detect air at a specified position in said circuit; and
a duration of said second time at least long enough to cause liquid to flow from a terminus of said circuit to said specified position, whereby leakage of liquid from any point in said circuit between said specified position and said terminus is assured.
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70. A leak detector for an infusion device that includes a circuit connectable to a patient to deliver fluid to a patient, comprising:
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a reversible conveyance connected to move fluid through said circuit;
an air detector in said circuit;
a controller configured to reverse said conveyance regularly and periodically to draw air into any leaks in said circuit and move said air to said air detector, whereby a leak in said circuit may be detected. - View Dependent Claims (71, 72, 73, 74)
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75. A leak detector for a blood processing machine with a draw circuit and a return circuit connected, respectively, to supply blood from a patient to, and return blood to said patient from, a blood processing device, comprising:
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a reversible conveyance connected in said draw and return circuits to drive blood therethrough;
a controller connected to control said reversible conveyance such that said reversible conveyance is regularly reversed each time a predefined volume of blood is passed through said return circuit;
at least one air sensor in at least one of said draw and return circuits;
said controller being configured such that a volume of blood displaced in reverse each time said reversible conveyance is reversed, is at least sufficient to transport fluid from a terminal end of said return circuit up to a point of being detectable by said at least one air sensor. - View Dependent Claims (76, 77, 78, 79, 80)
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81. A leak detector for a blood processing machine that includes a draw circuit and a return circuit connected, respectively, to supply blood from a patient to, and return blood to said patient from, a blood processing device, comprising:
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a reversible conveyance connected in said draw and return circuits to drive blood therethrough;
a controller connected to control said reversible conveyance such that said reversible conveyance is regularly reversed;
at least one air sensor in said circuit;
said controller being configured such that a volume of blood displaced in reverse each time said reversible conveyance is reversed is sufficient to insure blood from a terminal end of said return circuit is drawn at least to said at least one air sensor. - View Dependent Claims (82, 83, 84, 85)
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86. A device for detecting leaks and connectable to a blood processing system having an air sensor adapted to detect blood in a blood circuit, said blood circuit having draw and return lines:
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a conduit connectable to said return line;
a fluid conveyance connectable to said return line and said conduit and configured to connect said return line to a patient return access;
said conveyance being adapted to selectively and generate a reverse flow in said conduit and convey said reverse flow to said draw line;
a final control configured to control said conveyance to generate said reverse flow repeatedly during a treatment cycle of said blood processing leak detector.
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87. A leak detector for a blood processing machine that includes an access blood circuit connectable to a patient to remove blood from, and deliver blood to, said patient and a a process blood circuit including a treatment component adapted to treat blood circulated through said process blood circuit, comprising:
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a conveyance connected to move blood through said process and access blood circuits configured to generate a negative pressure in a return portion of said access blood circuit;
an detector configured to detect infiltration of air in said return portion;
a controller configured to generate said negative pressure in said conveyance repeatedly during a treatment cycle to draw air into said access circuit. - View Dependent Claims (88, 89)
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Specification