Method and apparatus for leak detection in a fluid line
First Claim
1. A method of detecting a loss of integrity in a blood circuit supplying blood to a patient, comprising the steps of:
- delivering blood to a patient through a circuit during first times;
said step of delivering including applying a positive gauge pressure to said circuit;
applying a negative pressure to said blood circuit during second times;
detecting a presence of air in said blood circuit during at least a portion of said second times, or after said second times, such that air infiltrating said blood circuit during said second times as a result of said negative pressure and a presence of a leak is detected.
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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 the 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.
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Citations
89 Claims
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1. A method of detecting a loss of integrity in a blood circuit supplying blood to a patient, comprising the steps of:
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delivering blood to a patient through a circuit during first times;
said step of delivering including applying a positive gauge pressure to said circuit;
applying a negative pressure to said blood circuit during second times;
detecting a presence of air in said blood circuit during at least a portion of said second times, or after said second times, such that air infiltrating said blood circuit during said second times as a result of said negative pressure and a presence of a leak is detected. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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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 blood processing machine, comprising:
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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;
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)
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18. 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)
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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)
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42. A method of detecting a leak in a fluid infusion or treatment system, comprising:
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providing a source of fluid to be pumped into a patient;
drawing from said source and conveying said fluid from said source to said patient during a first time;
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. - View Dependent Claims (43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53)
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54. A sterile contiguous fluid line for infusing a patient, comprising:
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a draw line connectable to at least one patient access;
a return line connectable to said at least one patient 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;
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 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 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 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. An infusion device for delivering a fluid to a patient, comprising:
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a circuit including a pump, a source end and a delivery end joined by said pump, 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 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 times;
said step of conveying including applying a positive gauge pressure to said circuit;
regularly applying a negative pressure to said circuit during second times;
detecting a presence of air in said liquid circuit during at least a portion of said second times, or after said second times, such that air infiltrating said circuit during said second times, 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)
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70. An infusion device, comprising:
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a circuit connectable to a patient to deliver fluid to a patient;
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 blood processing machine, comprising:
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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;
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 blood processing machine, comprising:
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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;
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 machine.
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87. A blood processing machine, comprising:
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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 adapted to treat blood circulated through said process blood circuit;
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