Features for protecting against leaks in a fluid circuit are disclosed. In a first embodiment, a fluid circuit is housed by another fluid circuit that is configured to capture and convey leaks to leak detector. In a second embodiment, a first indicator of a leak is used to trigger confirmation by blood flow reversal and air detection in the blood circuit.

One of the most significant safety concerns in the automation of extracorporeal blood treatments such as dialysis is the risk of blood leakage. Extracorporeal blood treatment systems draw blood at such a high rate that a loss of integrity in the blood circuit can be serious. There are a number of mechanisms for detecting and preventing leaks, but none is perfect. This tends to limit the use of such equipment in unsupervised settings, such as the home will be limited. Some leak detection schemes can be made sensitive enough to detect the barest of leaks, but when this is done, they result in too many false positives. The invention combines information from multiple inputs to enhance sensitivity in leak detection and reduce the problem of false positives.

A method and a system are provided for detecting a condition indicative of a dislodged needle in a hemodialysis procedure. A venous return pressure for a patient undergoing dialysis is measured. The venous return pressure is analyzed via a controller, and an intravascular blood pressure in proximity to a location of needle insertion into the patient is derived. A lower limit is calculated as a function of the intravascular blood pressure via the controller. An average of the venous return pressure is calculated via the controller during a predetermined time window. The average is compared to the lower limit via the controller, and if the average is within a specified range of the lower limit, the controller determines that a condition indicative of a dislodged needle is present.

An apparatus and method are disclosed for detecting the disconnection of a vascular access device such as a needle, cannula or catheter from a blood vessel or vascular graft segment. A pair of electrodes is placed in direct contact with fluid or blood in fluid communication with the vascular segment. In one embodiment, the electrodes are incorporated into a pair of connectors connecting arterial and venous catheters to arterial and venous tubes leading to and from an extracorporeal blood flow apparatus. Wires leading from the electrodes to a detecting circuit can be incorporated into a pair of double lumen arterial and venous tubes connecting the blood flow apparatus to the blood vessel or vascular graft. The detecting circuit is configured to provide a low-voltage alternating current signal to the electrodes to measure the electrical resistance between the electrodes, minimizing both the duration and amount of current being delivered. Detection of an increase in electrical resistance between the electrodes exceeding a pre-determined threshold value may be used to indicate a possible disconnection of the vascular access device.

Systems and methods used to detect blood leaks (in, for example, extracorporeal blood treatment apparatus) by detecting the presence of blood in liquid above a selected threshold amount based on the flow rate of the liquid flowing through a passage (for example, a tube, etc.) are described.

An apparatus and method for extracorporeal blood treatment, especially a dialysis apparatus, are disclosed, the apparatus includes a radar sensor for monitoring a patient located at a place of treatment.

An article configured to warm and monitor a patient during a dialysis treatment, the article includes one or more heating elements. The article also includes one or more sensors configured to monitor a condition of the patient during the dialysis treatment. The article also includes a fabric portion configured to receive the one or more heating elements and the one or more sensors and position the one or more heating elements and the one or more sensors on the patient during treatment. The article also includes a transmitter configured to transmit information from the one or more sensors to a dialysis machine and an electrical connector configured to provide power to at least one of the one or more heating elements and the one or more sensors.

A medical system, usable for example in connection with a dialysis apparatus, may utilize radar waves for monitoring a patient, a medical area, or an object. The medical system includes at least one sending device for sending radar waves, and at least one receiving device for receiving reflected radar waves. The medical system further includes an evaluation unit for evaluating the reflected radar waves which have been received by the at least one receiving device, resulting in obtaining a result, and an output device for outputting the result or a signal based on the result.

Graphical user interfaces for use with extracorporeal blood treatment systems may include a human-shaped graphical element and one or more process feature graphical elements. The human-shaped graphical element may be moved automatically or manually by users with respect to the process feature graphical elements to provide indications with respect to the process features corresponding to the human-shaped graphical element and the process feature graphical elements.

Features for protecting against leaks in a fluid circuit are disclosed. In an embodiment, a first indicator of a leak is used to trigger confirmation by blood flow reversal and air detection in the blood circuit. A method for performing a blood treatment includes, at blood treatment machine, pumping blood to a patient through a first blood line. Further, at a controller of the blood treatment machine, a first signal is received, indicating a probability of a leak in the first blood line. Responsively to the first signal, the controller commands a leak verification operation and receives a second signal indicating whether a leak in the first blood line is verified. Further, a leak indicating signal is generated if the second signal indicates a leak is verified.